Hi,
This is the 3rd version of the fetch-arg improvement series. This includes variable changes on fetcharg framework like,
- Add fetcharg testcases (syntax, argN, symbol, string and array) - Rewrite fetcharg framework with fetch_insn, switch-case based instead of function pointer. - Add "symbol" type support, which shows symbol+offset instead of address value. - Add "$argN" fetcharg, which fetches function parameters. (currently only for x86-64) - Add array type support (including string arrary :) ) , which enables to get fixed length array from probe-events.
V2 is here: https://lkml.org/lkml/2018/2/21/863
Changes from the v2 are here:
- [1/18] Use kstrtol instead of kstrtoul. (Thanks Namhyung!) - [7/18][8/18] Split out probe type table unification. - [14/18] Show $arg<N> in README only when this feature is supported - [16/18] Use ip register instead of top of stack for symbol type test
Last 2 changes are for non x86 environment, I've tested on arm/arm64.
Here are examples:
o 'symbol' type
# echo 'p vfs_read $stack0:symbol' > kprobe_events # echo 1 > events/kprobes/p_vfs_read_0/enable # tail -n 3 trace sh-729 [007] ...2 105.753637: p_vfs_read_0: (vfs_read+0x0/0x130) arg1=SyS_read+0x42/0x90 tail-736 [000] ...2 105.754904: p_vfs_read_0: (vfs_read+0x0/0x130) arg1=kernel_read+0x2c/0x40 tail-736 [000] ...2 105.754929: p_vfs_read_0: (vfs_read+0x0/0x130) arg1=kernel_read+0x2c/0x40
o $argN
# echo 'p vfs_read $arg0 $arg1 $arg2' > kprobe_events # echo 1 > events/kprobes/p_vfs_read_0/enable # tail -n 3 trace sh-726 [007] ...2 134.288973: p_vfs_read_0: (vfs_read+0x0/0x130) arg1=0xffff88001d98ec00 arg2=0x7ffeb4330f79 arg3=0x1 tail-731 [000] ...2 134.289987: p_vfs_read_0: (vfs_read+0x0/0x130) arg1=0xffff88001d9dd200 arg2=0xffff88001d8a0a00 arg3=0x80 tail-731 [000] ...2 134.290016: p_vfs_read_0: (vfs_read+0x0/0x130) arg1=0xffff88001d9dd200 arg2=0xffff88001faf4a00 arg3=0x150
o Array type
# echo 'p vfs_read +0($stack):x64 +0($stack):x8[8]' > kprobe_events # echo 1 > events/kprobes/p_vfs_read_0/enable # tail -n 3 trace sh-729 [007] ...2 91.701664: p_vfs_read_0: (vfs_read+0x0/0x130) arg1=0xffffffff811b1252 arg2={0x52,0x12,0x1b,0x81,0xff,0xff,0xff,0xff} tail-734 [000] ...2 91.702366: p_vfs_read_0: (vfs_read+0x0/0x130) arg1=0xffffffff811b0dec arg2={0xec,0xd,0x1b,0x81,0xff,0xff,0xff,0xff} tail-734 [000] ...2 91.702386: p_vfs_read_0: (vfs_read+0x0/0x130) arg1=0xffffffff811b0dec arg2={0xec,0xd,0x1b,0x81,0xff,0xff,0xff,0xff} # # cat events/kprobes/p_vfs_read_0/format name: p_vfs_read_0 ID: 1069 format: field:unsigned short common_type; offset:0; size:2; signed:0; field:unsigned char common_flags; offset:2; size:1; signed:0; field:unsigned char common_preempt_count; offset:3; size:1; signed:0; field:int common_pid; offset:4; size:4; signed:1;
field:unsigned long __probe_ip; offset:8; size:8; signed:0; field:u64 arg1; offset:16; size:0; signed:0; field:u8 arg2[8]; offset:24; size:8; signed:0;
print fmt: "(%lx) arg1=0x%Lx arg2={0x%x,0x%x,0x%x,0x%x,0x%x,0x%x,0x%x,0x%x}", REC->__probe_ip, REC->arg1, REC->arg2[0], REC->arg2[1], REC->arg2[2], REC->arg2[3], REC->arg2[4], REC->arg2[5], REC->arg2[6], REC->arg2[7]
o String Array type
# echo "p create_trace_kprobe arg1=+0(%si):string[3]" > kprobe_events # echo test1 test2 test3 >> kprobe_events sh: write error: Invalid argument # echo 'p vfs_read $stack' >> kprobe_events # tail -n 2 trace sh-744 [007] ...1 183.382407: p_create_trace_kprobe_0: (create_trace_kprobe+0x0/0x890) arg1={"test1","test2","test3"} sh-744 [007] ...1 230.487809: p_create_trace_kprobe_0: (create_trace_kprobe+0x0/0x890) arg1={"p","vfs_read","$stack"}
Thank you,
---
Masami Hiramatsu (18): [BUGFIX] tracing: probeevent: Fix to support minus offset from symbol selftests: ftrace: Add probe event argument syntax testcase selftests: ftrace: Add a testcase for string type with kprobe_event tracing: probeevent: Cleanup print argument functions tracing: probeevent: Cleanup argument field definition tracing: probeevent: Remove NOKPROBE_SYMBOL from print functions tracing: probeevent: Introduce new argument fetching code tracing: probeevent: Unify fetch type tables tracing: probeevent: Return consumed bytes of dynamic area tracing: probeevent: Append traceprobe_ for exported function tracing: probeevent: Unify fetch_insn processing common part tracing: probeevent: Add symbol type x86: ptrace: Add function argument access API tracing: probeevent: Add $argN for accessing function args tracing: probeevent: Add array type support selftests: ftrace: Add a testcase for symbol type selftests: ftrace: Add a testcase for $argN with kprobe_event selftests: ftrace: Add a testcase for array type with kprobe_event
Documentation/trace/kprobetrace.txt | 26 + arch/Kconfig | 7 arch/x86/Kconfig | 1 arch/x86/include/asm/ptrace.h | 38 + kernel/trace/trace.c | 9 kernel/trace/trace_kprobe.c | 366 ++++-------- kernel/trace/trace_probe.c | 629 +++++++++----------- kernel/trace/trace_probe.h | 284 +++------ kernel/trace/trace_probe_tmpl.h | 214 +++++++ kernel/trace/trace_uprobe.c | 168 ++--- .../ftrace/test.d/kprobe/kprobe_args_argN.tc | 25 + .../ftrace/test.d/kprobe/kprobe_args_array.tc | 75 ++ .../ftrace/test.d/kprobe/kprobe_args_string.tc | 46 + .../ftrace/test.d/kprobe/kprobe_args_symbol.tc | 77 ++ .../ftrace/test.d/kprobe/kprobe_args_syntax.tc | 97 +++ 15 files changed, 1171 insertions(+), 891 deletions(-) create mode 100644 kernel/trace/trace_probe_tmpl.h create mode 100644 tools/testing/selftests/ftrace/test.d/kprobe/kprobe_args_argN.tc create mode 100644 tools/testing/selftests/ftrace/test.d/kprobe/kprobe_args_array.tc create mode 100644 tools/testing/selftests/ftrace/test.d/kprobe/kprobe_args_string.tc create mode 100644 tools/testing/selftests/ftrace/test.d/kprobe/kprobe_args_symbol.tc create mode 100644 tools/testing/selftests/ftrace/test.d/kprobe/kprobe_args_syntax.tc
-- Masami Hiramatsu (Linaro) mhiramat@kernel.org -- To unsubscribe from this list: send the line "unsubscribe linux-kselftest" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
In Documentation/trace/kprobetrace.txt, it says
@SYM[+|-offs] : Fetch memory at SYM +|- offs (SYM should be a data symbol)
However, the parser doesn't parse minus offset correctly, since commit 2fba0c8867af ("tracing/kprobes: Fix probe offset to be unsigned") drops minus ("-") offset support for kprobe probe address usage.
This fixes the traceprobe_split_symbol_offset() to parse minus offset again with checking the offset range, and add a minus offset check in kprobe probe address usage.
Fixes: 2fba0c8867af ("tracing/kprobes: Fix probe offset to be unsigned") Signed-off-by: Masami Hiramatsu mhiramat@kernel.org --- Changes in v3: - Use kstrtol instead of kstrtoul. (Thanks Namhyung!) --- kernel/trace/trace_kprobe.c | 4 ++-- kernel/trace/trace_probe.c | 8 +++----- kernel/trace/trace_probe.h | 2 +- 3 files changed, 6 insertions(+), 8 deletions(-)
diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c index 5ce9b8cf7be3..b5b1d8aa47d6 100644 --- a/kernel/trace/trace_kprobe.c +++ b/kernel/trace/trace_kprobe.c @@ -667,7 +667,7 @@ static int create_trace_kprobe(int argc, char **argv) char *symbol = NULL, *event = NULL, *group = NULL; int maxactive = 0; char *arg; - unsigned long offset = 0; + long offset = 0; void *addr = NULL; char buf[MAX_EVENT_NAME_LEN];
@@ -755,7 +755,7 @@ static int create_trace_kprobe(int argc, char **argv) symbol = argv[1]; /* TODO: support .init module functions */ ret = traceprobe_split_symbol_offset(symbol, &offset); - if (ret) { + if (ret || offset < 0) { pr_info("Failed to parse either an address or a symbol.\n"); return ret; } diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c index d59357308677..d3d1ee820336 100644 --- a/kernel/trace/trace_probe.c +++ b/kernel/trace/trace_probe.c @@ -320,7 +320,7 @@ static fetch_func_t get_fetch_size_function(const struct fetch_type *type, }
/* Split symbol and offset. */ -int traceprobe_split_symbol_offset(char *symbol, unsigned long *offset) +int traceprobe_split_symbol_offset(char *symbol, long *offset) { char *tmp; int ret; @@ -328,13 +328,11 @@ int traceprobe_split_symbol_offset(char *symbol, unsigned long *offset) if (!offset) return -EINVAL;
- tmp = strchr(symbol, '+'); + tmp = strpbrk(symbol, "+-"); if (tmp) { - /* skip sign because kstrtoul doesn't accept '+' */ - ret = kstrtoul(tmp + 1, 0, offset); + ret = kstrtol(tmp + 1, 0, offset); if (ret) return ret; - *tmp = '\0'; } else *offset = 0; diff --git a/kernel/trace/trace_probe.h b/kernel/trace/trace_probe.h index 0745f895f780..75daff22ccea 100644 --- a/kernel/trace/trace_probe.h +++ b/kernel/trace/trace_probe.h @@ -365,7 +365,7 @@ extern int traceprobe_conflict_field_name(const char *name, extern void traceprobe_update_arg(struct probe_arg *arg); extern void traceprobe_free_probe_arg(struct probe_arg *arg);
-extern int traceprobe_split_symbol_offset(char *symbol, unsigned long *offset); +extern int traceprobe_split_symbol_offset(char *symbol, long *offset);
/* Sum up total data length for dynamic arraies (strings) */ static nokprobe_inline int
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Add a testcase for probe event argument syntax which ensures the kprobe_events interface correctly parses given event arguments.
Signed-off-by: Masami Hiramatsu mhiramat@kernel.org --- .../ftrace/test.d/kprobe/kprobe_args_syntax.tc | 97 ++++++++++++++++++++ 1 file changed, 97 insertions(+) create mode 100644 tools/testing/selftests/ftrace/test.d/kprobe/kprobe_args_syntax.tc
diff --git a/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_args_syntax.tc b/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_args_syntax.tc new file mode 100644 index 000000000000..231bcd2c4eb5 --- /dev/null +++ b/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_args_syntax.tc @@ -0,0 +1,97 @@ +#!/bin/sh +# SPDX-License-Identifier: GPL-2.0 +# description: Kprobe event argument syntax + +[ -f kprobe_events ] || exit_unsupported # this is configurable + +grep "x8/16/32/64" README > /dev/null || exit_unsupported # version issue + +echo 0 > events/enable +echo > kprobe_events + +PROBEFUNC="vfs_read" +GOODREG= +BADREG= +GOODSYM="_sdata" +if ! grep -qw ${GOODSYM} /proc/kallsyms ; then + GOODSYM=$PROBEFUNC +fi +BADSYM="deaqswdefr" +SYMADDR=0x`grep -w ${GOODSYM} /proc/kallsyms | cut -f 1 -d " "` +GOODTYPE="x16" +BADTYPE="y16" + +case `uname -m` in +x86_64|i[3456]86) + GOODREG=%ax + BADREG=%ex +;; +aarch64) + GOODREG=%x0 + BADREG=%ax +;; +arm*) + GOODREG=%r0 + BADREG=%ax +;; +esac + +test_goodarg() # Good-args +{ + while [ "$1" ]; do + echo "p ${PROBEFUNC} $1" > kprobe_events + shift 1 + done; +} + +test_badarg() # Bad-args +{ + while [ "$1" ]; do + ! echo "p ${PROBEFUNC} $1" > kprobe_events + shift 1 + done; +} + +echo > kprobe_events + +: "Register access" +test_goodarg ${GOODREG} +test_badarg ${BADREG} + +: "Symbol access" +test_goodarg "@${GOODSYM}" "@${SYMADDR}" "@${GOODSYM}+10" "@${GOODSYM}-10" +test_badarg "@" "@${BADSYM}" "@${GOODSYM}*10" "@${GOODSYM}/10" \ + "@${GOODSYM}%10" "@${GOODSYM}&10" "@${GOODSYM}|10" + +: "Stack access" +test_goodarg "$stack" "$stack0" "$stack1" +test_badarg "$stackp" "$stack0+10" "$stack1-10" + +: "Retval access" +echo "r ${PROBEFUNC} $retval" > kprobe_events +! echo "p ${PROBEFUNC} $retval" > kprobe_events + +: "Comm access" +test_goodarg "$comm" + +: "Indirect memory access" +test_goodarg "+0(${GOODREG})" "-0(${GOODREG})" "+10($stack)" \ + "+0($stack1)" "+10(@${GOODSYM}-10)" "+0(+10(+20($stack)))" +test_badarg "+(${GOODREG})" "(${GOODREG}+10)" "-(${GOODREG})" "(${GOODREG})" \ + "+10($comm)" "+0(${GOODREG})+10" + +: "Name assignment" +test_goodarg "varname=${GOODREG}" +test_badarg "varname=varname2=${GOODREG}" + +: "Type syntax" +test_goodarg "${GOODREG}:${GOODTYPE}" +test_badarg "${GOODREG}::${GOODTYPE}" "${GOODREG}:${BADTYPE}" \ + "${GOODTYPE}:${GOODREG}" + +: "Combination check" + +test_goodarg "$comm:string" "+0($stack):string" +test_badarg "$comm:x64" "$stack:string" "${GOODREG}:string" + +echo > kprobe_events
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Add a testcase for string type with kprobe event. This tests good/bad syntax combinations and also the traced data is correct in several way.
Signed-off-by: Masami Hiramatsu mhiramat@kernel.org --- .../ftrace/test.d/kprobe/kprobe_args_string.tc | 46 ++++++++++++++++++++ 1 file changed, 46 insertions(+) create mode 100644 tools/testing/selftests/ftrace/test.d/kprobe/kprobe_args_string.tc
diff --git a/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_args_string.tc b/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_args_string.tc new file mode 100644 index 000000000000..5ba73035e1d9 --- /dev/null +++ b/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_args_string.tc @@ -0,0 +1,46 @@ +#!/bin/sh +# SPDX-License-Identifier: GPL-2.0 +# description: Kprobe event string type argument + +[ -f kprobe_events ] || exit_unsupported # this is configurable + +echo 0 > events/enable +echo > kprobe_events + +case `uname -m` in +x86_64) + ARG2=%si + OFFS=8 +;; +i[3456]86) + ARG2=%cx + OFFS=4 +;; +aarch64) + ARG2=%x1 + OFFS=8 +;; +arm*) + ARG2=%r1 + OFFS=4 +;; +*) + echo "Please implement other architecture here" + exit_untested +esac + +: "Test get argument (1)" +echo "p:testprobe create_trace_kprobe arg1=+0(+0(${ARG2})):string" > kprobe_events +echo 1 > events/kprobes/testprobe/enable +! echo test >> kprobe_events +tail -n 1 trace | grep -qe "testprobe.* arg1="test"" + +echo 0 > events/kprobes/testprobe/enable +: "Test get argument (2)" +echo "p:testprobe create_trace_kprobe arg1=+0(+0(${ARG2})):string arg2=+0(+${OFFS}(${ARG2})):string" > kprobe_events +echo 1 > events/kprobes/testprobe/enable +! echo test1 test2 >> kprobe_events +tail -n 1 trace | grep -qe "testprobe.* arg1="test1" arg2="test2"" + +echo 0 > events/enable +echo > kprobe_events
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Current print argument functions prints the argument name too. It is not good for printing out multiple values for one argument. This change it to just print out the value.
Signed-off-by: Masami Hiramatsu mhiramat@kernel.org --- kernel/trace/trace_kprobe.c | 20 ++++++-------------- kernel/trace/trace_probe.c | 12 +++++------- kernel/trace/trace_probe.h | 19 ++++++++++++++++--- kernel/trace/trace_uprobe.c | 9 ++------- 4 files changed, 29 insertions(+), 31 deletions(-)
diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c index b5b1d8aa47d6..503827750446 100644 --- a/kernel/trace/trace_kprobe.c +++ b/kernel/trace/trace_kprobe.c @@ -1090,8 +1090,6 @@ print_kprobe_event(struct trace_iterator *iter, int flags, struct kprobe_trace_entry_head *field; struct trace_seq *s = &iter->seq; struct trace_probe *tp; - u8 *data; - int i;
field = (struct kprobe_trace_entry_head *)iter->ent; tp = container_of(event, struct trace_probe, call.event); @@ -1103,11 +1101,9 @@ print_kprobe_event(struct trace_iterator *iter, int flags,
trace_seq_putc(s, ')');
- data = (u8 *)&field[1]; - for (i = 0; i < tp->nr_args; i++) - if (!tp->args[i].type->print(s, tp->args[i].name, - data + tp->args[i].offset, field)) - goto out; + if (print_probe_args(s, tp->args, tp->nr_args, + (u8 *)&field[1], field) < 0) + goto out;
trace_seq_putc(s, '\n'); out: @@ -1121,8 +1117,6 @@ print_kretprobe_event(struct trace_iterator *iter, int flags, struct kretprobe_trace_entry_head *field; struct trace_seq *s = &iter->seq; struct trace_probe *tp; - u8 *data; - int i;
field = (struct kretprobe_trace_entry_head *)iter->ent; tp = container_of(event, struct trace_probe, call.event); @@ -1139,11 +1133,9 @@ print_kretprobe_event(struct trace_iterator *iter, int flags,
trace_seq_putc(s, ')');
- data = (u8 *)&field[1]; - for (i = 0; i < tp->nr_args; i++) - if (!tp->args[i].type->print(s, tp->args[i].name, - data + tp->args[i].offset, field)) - goto out; + if (print_probe_args(s, tp->args, tp->nr_args, + (u8 *)&field[1], field) < 0) + goto out;
trace_seq_putc(s, '\n');
diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c index d3d1ee820336..e90cccf0adc7 100644 --- a/kernel/trace/trace_probe.c +++ b/kernel/trace/trace_probe.c @@ -38,10 +38,9 @@ const char *reserved_field_names[] = {
/* Printing in basic type function template */ #define DEFINE_BASIC_PRINT_TYPE_FUNC(tname, type, fmt) \ -int PRINT_TYPE_FUNC_NAME(tname)(struct trace_seq *s, const char *name, \ - void *data, void *ent) \ +int PRINT_TYPE_FUNC_NAME(tname)(struct trace_seq *s, void *data, void *ent)\ { \ - trace_seq_printf(s, " %s=" fmt, name, *(type *)data); \ + trace_seq_printf(s, fmt, *(type *)data); \ return !trace_seq_has_overflowed(s); \ } \ const char PRINT_TYPE_FMT_NAME(tname)[] = fmt; \ @@ -61,15 +60,14 @@ DEFINE_BASIC_PRINT_TYPE_FUNC(x32, u32, "0x%x") DEFINE_BASIC_PRINT_TYPE_FUNC(x64, u64, "0x%Lx")
/* Print type function for string type */ -int PRINT_TYPE_FUNC_NAME(string)(struct trace_seq *s, const char *name, - void *data, void *ent) +int PRINT_TYPE_FUNC_NAME(string)(struct trace_seq *s, void *data, void *ent) { int len = *(u32 *)data >> 16;
if (!len) - trace_seq_printf(s, " %s=(fault)", name); + trace_seq_puts(s, "(fault)"); else - trace_seq_printf(s, " %s="%s"", name, + trace_seq_printf(s, ""%s"", (const char *)get_loc_data(data, ent)); return !trace_seq_has_overflowed(s); } diff --git a/kernel/trace/trace_probe.h b/kernel/trace/trace_probe.h index 75daff22ccea..0c8e66f9c855 100644 --- a/kernel/trace/trace_probe.h +++ b/kernel/trace/trace_probe.h @@ -94,7 +94,7 @@ static nokprobe_inline void *get_loc_data(u32 *dl, void *ent) /* Data fetch function type */ typedef void (*fetch_func_t)(struct pt_regs *, void *, void *); /* Printing function type */ -typedef int (*print_type_func_t)(struct trace_seq *, const char *, void *, void *); +typedef int (*print_type_func_t)(struct trace_seq *, void *, void *);
/* Fetch types */ enum { @@ -136,8 +136,7 @@ typedef u32 string_size;
/* Printing in basic type function template */ #define DECLARE_BASIC_PRINT_TYPE_FUNC(type) \ -int PRINT_TYPE_FUNC_NAME(type)(struct trace_seq *s, const char *name, \ - void *data, void *ent); \ +int PRINT_TYPE_FUNC_NAME(type)(struct trace_seq *s, void *data, void *ent);\ extern const char PRINT_TYPE_FMT_NAME(type)[]
DECLARE_BASIC_PRINT_TYPE_FUNC(u8); @@ -415,6 +414,20 @@ store_trace_args(int ent_size, struct trace_probe *tp, struct pt_regs *regs, } }
+static inline int +print_probe_args(struct trace_seq *s, struct probe_arg *args, int nr_args, + u8 *data, void *field) +{ + int i; + + for (i = 0; i < nr_args; i++) { + trace_seq_printf(s, " %s=", args[i].name); + if (!args[i].type->print(s, data + args[i].offset, field)) + return -ENOMEM; + } + return 0; +} + extern int set_print_fmt(struct trace_probe *tp, bool is_return);
#ifdef CONFIG_PERF_EVENTS diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c index 2014f4351ae0..4c006a693663 100644 --- a/kernel/trace/trace_uprobe.c +++ b/kernel/trace/trace_uprobe.c @@ -864,7 +864,6 @@ print_uprobe_event(struct trace_iterator *iter, int flags, struct trace_event *e struct trace_seq *s = &iter->seq; struct trace_uprobe *tu; u8 *data; - int i;
entry = (struct uprobe_trace_entry_head *)iter->ent; tu = container_of(event, struct trace_uprobe, tp.call.event); @@ -881,12 +880,8 @@ print_uprobe_event(struct trace_iterator *iter, int flags, struct trace_event *e data = DATAOF_TRACE_ENTRY(entry, false); }
- for (i = 0; i < tu->tp.nr_args; i++) { - struct probe_arg *parg = &tu->tp.args[i]; - - if (!parg->type->print(s, parg->name, data + parg->offset, entry)) - goto out; - } + if (print_probe_args(s, tu->tp.args, tu->tp.nr_args, data, entry) < 0) + goto out;
trace_seq_putc(s, '\n');
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Cleanup event argument definition code in one place for maintenancability.
Signed-off-by: Masami Hiramatsu mhiramat@kernel.org --- kernel/trace/trace_kprobe.c | 32 ++++---------------------------- kernel/trace/trace_probe.c | 21 +++++++++++++++++++++ kernel/trace/trace_probe.h | 2 ++ kernel/trace/trace_uprobe.c | 15 ++------------- 4 files changed, 29 insertions(+), 41 deletions(-)
diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c index 503827750446..1018867022b6 100644 --- a/kernel/trace/trace_kprobe.c +++ b/kernel/trace/trace_kprobe.c @@ -1146,49 +1146,25 @@ print_kretprobe_event(struct trace_iterator *iter, int flags,
static int kprobe_event_define_fields(struct trace_event_call *event_call) { - int ret, i; + int ret; struct kprobe_trace_entry_head field; struct trace_kprobe *tk = (struct trace_kprobe *)event_call->data;
DEFINE_FIELD(unsigned long, ip, FIELD_STRING_IP, 0); - /* Set argument names as fields */ - for (i = 0; i < tk->tp.nr_args; i++) { - struct probe_arg *parg = &tk->tp.args[i];
- ret = trace_define_field(event_call, parg->type->fmttype, - parg->name, - sizeof(field) + parg->offset, - parg->type->size, - parg->type->is_signed, - FILTER_OTHER); - if (ret) - return ret; - } - return 0; + return traceprobe_define_arg_fields(event_call, sizeof(field), &tk->tp); }
static int kretprobe_event_define_fields(struct trace_event_call *event_call) { - int ret, i; + int ret; struct kretprobe_trace_entry_head field; struct trace_kprobe *tk = (struct trace_kprobe *)event_call->data;
DEFINE_FIELD(unsigned long, func, FIELD_STRING_FUNC, 0); DEFINE_FIELD(unsigned long, ret_ip, FIELD_STRING_RETIP, 0); - /* Set argument names as fields */ - for (i = 0; i < tk->tp.nr_args; i++) { - struct probe_arg *parg = &tk->tp.args[i];
- ret = trace_define_field(event_call, parg->type->fmttype, - parg->name, - sizeof(field) + parg->offset, - parg->type->size, - parg->type->is_signed, - FILTER_OTHER); - if (ret) - return ret; - } - return 0; + return traceprobe_define_arg_fields(event_call, sizeof(field), &tk->tp); }
#ifdef CONFIG_PERF_EVENTS diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c index e90cccf0adc7..92d96ed6a2bf 100644 --- a/kernel/trace/trace_probe.c +++ b/kernel/trace/trace_probe.c @@ -680,3 +680,24 @@ int set_print_fmt(struct trace_probe *tp, bool is_return)
return 0; } + +int traceprobe_define_arg_fields(struct trace_event_call *event_call, + size_t offset, struct trace_probe *tp) +{ + int ret, i; + + /* Set argument names as fields */ + for (i = 0; i < tp->nr_args; i++) { + struct probe_arg *parg = &tp->args[i]; + + ret = trace_define_field(event_call, parg->type->fmttype, + parg->name, + offset + parg->offset, + parg->type->size, + parg->type->is_signed, + FILTER_OTHER); + if (ret) + return ret; + } + return 0; +} diff --git a/kernel/trace/trace_probe.h b/kernel/trace/trace_probe.h index 0c8e66f9c855..de928052926b 100644 --- a/kernel/trace/trace_probe.h +++ b/kernel/trace/trace_probe.h @@ -440,3 +440,5 @@ extern struct trace_event_call * create_local_trace_uprobe(char *name, unsigned long offs, bool is_return); extern void destroy_local_trace_uprobe(struct trace_event_call *event_call); #endif +extern int traceprobe_define_arg_fields(struct trace_event_call *event_call, + size_t offset, struct trace_probe *tp); diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c index 4c006a693663..887da2bb63aa 100644 --- a/kernel/trace/trace_uprobe.c +++ b/kernel/trace/trace_uprobe.c @@ -982,7 +982,7 @@ probe_event_disable(struct trace_uprobe *tu, struct trace_event_file *file)
static int uprobe_event_define_fields(struct trace_event_call *event_call) { - int ret, i, size; + int ret, size; struct uprobe_trace_entry_head field; struct trace_uprobe *tu = event_call->data;
@@ -994,19 +994,8 @@ static int uprobe_event_define_fields(struct trace_event_call *event_call) DEFINE_FIELD(unsigned long, vaddr[0], FIELD_STRING_IP, 0); size = SIZEOF_TRACE_ENTRY(false); } - /* Set argument names as fields */ - for (i = 0; i < tu->tp.nr_args; i++) { - struct probe_arg *parg = &tu->tp.args[i]; - - ret = trace_define_field(event_call, parg->type->fmttype, - parg->name, size + parg->offset, - parg->type->size, parg->type->is_signed, - FILTER_OTHER);
- if (ret) - return ret; - } - return 0; + return traceprobe_define_arg_fields(event_call, size, &tu->tp); }
#ifdef CONFIG_PERF_EVENTS
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Remove unneeded NOKPROBE_SYMBOL from print functions since the print functions are only used when printing out the trace data, and not from kprobe handler.
Signed-off-by: Masami Hiramatsu mhiramat@kernel.org --- kernel/trace/trace_probe.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-)
diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c index 92d96ed6a2bf..0a809efabeb6 100644 --- a/kernel/trace/trace_probe.c +++ b/kernel/trace/trace_probe.c @@ -43,8 +43,7 @@ int PRINT_TYPE_FUNC_NAME(tname)(struct trace_seq *s, void *data, void *ent)\ trace_seq_printf(s, fmt, *(type *)data); \ return !trace_seq_has_overflowed(s); \ } \ -const char PRINT_TYPE_FMT_NAME(tname)[] = fmt; \ -NOKPROBE_SYMBOL(PRINT_TYPE_FUNC_NAME(tname)); +const char PRINT_TYPE_FMT_NAME(tname)[] = fmt;
DEFINE_BASIC_PRINT_TYPE_FUNC(u8, u8, "%u") DEFINE_BASIC_PRINT_TYPE_FUNC(u16, u16, "%u") @@ -71,7 +70,6 @@ int PRINT_TYPE_FUNC_NAME(string)(struct trace_seq *s, void *data, void *ent) (const char *)get_loc_data(data, ent)); return !trace_seq_has_overflowed(s); } -NOKPROBE_SYMBOL(PRINT_TYPE_FUNC_NAME(string));
const char PRINT_TYPE_FMT_NAME(string)[] = "\"%s\"";
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Replace {k,u}probe event argument fetching framework with switch-case based. Currently that is implemented with structures, macros and chain of function-pointers, which is more complicated than necessary and may get a performance penalty by retpoline.
This simplify that with an array of "fetch_insn" (opcode and oprands), and make process_fetch_insn() just interprets it. No function pointers are used.
Signed-off-by: Masami Hiramatsu mhiramat@kernel.org --- Changes in v3: - Split out probe type table unification. --- kernel/trace/trace_kprobe.c | 291 +++++++++++++--------------- kernel/trace/trace_probe.c | 401 +++++++++++---------------------------- kernel/trace/trace_probe.h | 230 ++++------------------ kernel/trace/trace_probe_tmpl.h | 120 ++++++++++++ kernel/trace/trace_uprobe.c | 127 ++++++++---- 5 files changed, 491 insertions(+), 678 deletions(-) create mode 100644 kernel/trace/trace_probe_tmpl.h
diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c index 1018867022b6..8423815ff986 100644 --- a/kernel/trace/trace_kprobe.c +++ b/kernel/trace/trace_kprobe.c @@ -24,6 +24,7 @@ #include <linux/error-injection.h>
#include "trace_probe.h" +#include "trace_probe_tmpl.h"
#define KPROBE_EVENT_SYSTEM "kprobes" #define KRETPROBE_MAXACTIVE_MAX 4096 @@ -121,160 +122,6 @@ static int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs); static int kretprobe_dispatcher(struct kretprobe_instance *ri, struct pt_regs *regs);
-/* Memory fetching by symbol */ -struct symbol_cache { - char *symbol; - long offset; - unsigned long addr; -}; - -unsigned long update_symbol_cache(struct symbol_cache *sc) -{ - sc->addr = (unsigned long)kallsyms_lookup_name(sc->symbol); - - if (sc->addr) - sc->addr += sc->offset; - - return sc->addr; -} - -void free_symbol_cache(struct symbol_cache *sc) -{ - kfree(sc->symbol); - kfree(sc); -} - -struct symbol_cache *alloc_symbol_cache(const char *sym, long offset) -{ - struct symbol_cache *sc; - - if (!sym || strlen(sym) == 0) - return NULL; - - sc = kzalloc(sizeof(struct symbol_cache), GFP_KERNEL); - if (!sc) - return NULL; - - sc->symbol = kstrdup(sym, GFP_KERNEL); - if (!sc->symbol) { - kfree(sc); - return NULL; - } - sc->offset = offset; - update_symbol_cache(sc); - - return sc; -} - -/* - * Kprobes-specific fetch functions - */ -#define DEFINE_FETCH_stack(type) \ -static void FETCH_FUNC_NAME(stack, type)(struct pt_regs *regs, \ - void *offset, void *dest) \ -{ \ - *(type *)dest = (type)regs_get_kernel_stack_nth(regs, \ - (unsigned int)((unsigned long)offset)); \ -} \ -NOKPROBE_SYMBOL(FETCH_FUNC_NAME(stack, type)); - -DEFINE_BASIC_FETCH_FUNCS(stack) -/* No string on the stack entry */ -#define fetch_stack_string NULL -#define fetch_stack_string_size NULL - -#define DEFINE_FETCH_memory(type) \ -static void FETCH_FUNC_NAME(memory, type)(struct pt_regs *regs, \ - void *addr, void *dest) \ -{ \ - type retval; \ - if (probe_kernel_address(addr, retval)) \ - *(type *)dest = 0; \ - else \ - *(type *)dest = retval; \ -} \ -NOKPROBE_SYMBOL(FETCH_FUNC_NAME(memory, type)); - -DEFINE_BASIC_FETCH_FUNCS(memory) -/* - * Fetch a null-terminated string. Caller MUST set *(u32 *)dest with max - * length and relative data location. - */ -static void FETCH_FUNC_NAME(memory, string)(struct pt_regs *regs, - void *addr, void *dest) -{ - int maxlen = get_rloc_len(*(u32 *)dest); - u8 *dst = get_rloc_data(dest); - long ret; - - if (!maxlen) - return; - - /* - * Try to get string again, since the string can be changed while - * probing. - */ - ret = strncpy_from_unsafe(dst, addr, maxlen); - - if (ret < 0) { /* Failed to fetch string */ - dst[0] = '\0'; - *(u32 *)dest = make_data_rloc(0, get_rloc_offs(*(u32 *)dest)); - } else { - *(u32 *)dest = make_data_rloc(ret, get_rloc_offs(*(u32 *)dest)); - } -} -NOKPROBE_SYMBOL(FETCH_FUNC_NAME(memory, string)); - -/* Return the length of string -- including null terminal byte */ -static void FETCH_FUNC_NAME(memory, string_size)(struct pt_regs *regs, - void *addr, void *dest) -{ - mm_segment_t old_fs; - int ret, len = 0; - u8 c; - - old_fs = get_fs(); - set_fs(KERNEL_DS); - pagefault_disable(); - - do { - ret = __copy_from_user_inatomic(&c, (u8 *)addr + len, 1); - len++; - } while (c && ret == 0 && len < MAX_STRING_SIZE); - - pagefault_enable(); - set_fs(old_fs); - - if (ret < 0) /* Failed to check the length */ - *(u32 *)dest = 0; - else - *(u32 *)dest = len; -} -NOKPROBE_SYMBOL(FETCH_FUNC_NAME(memory, string_size)); - -#define DEFINE_FETCH_symbol(type) \ -void FETCH_FUNC_NAME(symbol, type)(struct pt_regs *regs, void *data, void *dest)\ -{ \ - struct symbol_cache *sc = data; \ - if (sc->addr) \ - fetch_memory_##type(regs, (void *)sc->addr, dest); \ - else \ - *(type *)dest = 0; \ -} \ -NOKPROBE_SYMBOL(FETCH_FUNC_NAME(symbol, type)); - -DEFINE_BASIC_FETCH_FUNCS(symbol) -DEFINE_FETCH_symbol(string) -DEFINE_FETCH_symbol(string_size) - -/* kprobes don't support file_offset fetch methods */ -#define fetch_file_offset_u8 NULL -#define fetch_file_offset_u16 NULL -#define fetch_file_offset_u32 NULL -#define fetch_file_offset_u64 NULL -#define fetch_file_offset_string NULL -#define fetch_file_offset_string_size NULL - /* Fetch type information table */ static const struct fetch_type kprobes_fetch_type_table[] = { /* Special types */ @@ -490,14 +337,11 @@ disable_trace_kprobe(struct trace_kprobe *tk, struct trace_event_file *file) /* Internal register function - just handle k*probes and flags */ static int __register_trace_kprobe(struct trace_kprobe *tk) { - int i, ret; + int ret;
if (trace_probe_is_registered(&tk->tp)) return -EINVAL;
- for (i = 0; i < tk->tp.nr_args; i++) - traceprobe_update_arg(&tk->tp.args[i]); - /* Set/clear disabled flag according to tp->flag */ if (trace_probe_is_enabled(&tk->tp)) tk->rp.kp.flags &= ~KPROBE_FLAG_DISABLED; @@ -830,8 +674,8 @@ static int create_trace_kprobe(int argc, char **argv)
/* Parse fetch argument */ ret = traceprobe_parse_probe_arg(arg, &tk->tp.size, parg, - is_return, true, - kprobes_fetch_type_table); + is_return, true, + kprobes_fetch_type_table); if (ret) { pr_info("Parse error at argument[%d]. (%d)\n", i, ret); goto error; @@ -985,6 +829,133 @@ static const struct file_operations kprobe_profile_ops = { .release = seq_release, };
+/* Kprobe specific fetch functions */ + +/* Return the length of string -- including null terminal byte */ +static nokprobe_inline void +fetch_store_strlen(unsigned long addr, void *dest) +{ + mm_segment_t old_fs; + int ret, len = 0; + u8 c; + + old_fs = get_fs(); + set_fs(KERNEL_DS); + pagefault_disable(); + + do { + ret = __copy_from_user_inatomic(&c, (u8 *)addr + len, 1); + len++; + } while (c && ret == 0 && len < MAX_STRING_SIZE); + + pagefault_enable(); + set_fs(old_fs); + + if (ret < 0) /* Failed to check the length */ + *(u32 *)dest = 0; + else + *(u32 *)dest = len; +} + +/* + * Fetch a null-terminated string. Caller MUST set *(u32 *)buf with max + * length and relative data location. + */ +static nokprobe_inline void +fetch_store_string(unsigned long addr, void *dest) +{ + int maxlen = get_rloc_len(*(u32 *)dest); + u8 *dst = get_rloc_data(dest); + long ret; + + if (!maxlen) + return; + + /* + * Try to get string again, since the string can be changed while + * probing. + */ + ret = strncpy_from_unsafe(dst, (void *)addr, maxlen); + + if (ret < 0) { /* Failed to fetch string */ + dst[0] = '\0'; + *(u32 *)dest = make_data_rloc(0, get_rloc_offs(*(u32 *)dest)); + } else { + *(u32 *)dest = make_data_rloc(ret, get_rloc_offs(*(u32 *)dest)); + } +} + +/* Note that we don't verify it, since the code does not come from user space */ +static int +process_fetch_insn(struct fetch_insn *code, struct pt_regs *regs, void *dest, + bool pre) +{ + unsigned long val; + int ret; + + /* 1st stage: get value from context */ + switch (code->op) { + case FETCH_OP_REG: + val = regs_get_register(regs, code->param); + break; + case FETCH_OP_STACK: + val = regs_get_kernel_stack_nth(regs, code->param); + break; + case FETCH_OP_STACKP: + val = kernel_stack_pointer(regs); + break; + case FETCH_OP_RETVAL: + val = regs_return_value(regs); + break; + case FETCH_OP_IMM: + val = code->immediate; + break; + case FETCH_OP_COMM: + val = (unsigned long)current->comm; + break; + default: + return -EILSEQ; + } + code++; + + /* 2nd stage: dereference memory if needed */ + while (code->op == FETCH_OP_DEREF) { + ret = probe_kernel_read(&val, (void *)val + code->offset, + sizeof(val)); + if (ret) + return ret; + code++; + } + + /* 3rd stage: store value to buffer */ + switch (code->op) { + case FETCH_OP_ST_RAW: + fetch_store_raw(val, code, dest); + break; + case FETCH_OP_ST_MEM: + probe_kernel_read(dest, (void *)val + code->offset, code->size); + break; + case FETCH_OP_ST_STRING: + if (pre) + fetch_store_strlen(val + code->offset, dest); + else + fetch_store_string(val + code->offset, dest); + break; + default: + return -EILSEQ; + } + code++; + + /* 4th stage: modify stored value if needed */ + if (code->op == FETCH_OP_MOD_BF) { + fetch_apply_bitfield(code, dest); + code++; + } + + return code->op == FETCH_OP_END ? 0 : -EILSEQ; +} +NOKPROBE_SYMBOL(process_fetch_insn) + /* Kprobe handler */ static nokprobe_inline void __kprobe_trace_func(struct trace_kprobe *tk, struct pt_regs *regs, diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c index 0a809efabeb6..a7e36606718a 100644 --- a/kernel/trace/trace_probe.c +++ b/kernel/trace/trace_probe.c @@ -73,174 +73,6 @@ int PRINT_TYPE_FUNC_NAME(string)(struct trace_seq *s, void *data, void *ent)
const char PRINT_TYPE_FMT_NAME(string)[] = "\"%s\"";
-#define CHECK_FETCH_FUNCS(method, fn) \ - (((FETCH_FUNC_NAME(method, u8) == fn) || \ - (FETCH_FUNC_NAME(method, u16) == fn) || \ - (FETCH_FUNC_NAME(method, u32) == fn) || \ - (FETCH_FUNC_NAME(method, u64) == fn) || \ - (FETCH_FUNC_NAME(method, string) == fn) || \ - (FETCH_FUNC_NAME(method, string_size) == fn)) \ - && (fn != NULL)) - -/* Data fetch function templates */ -#define DEFINE_FETCH_reg(type) \ -void FETCH_FUNC_NAME(reg, type)(struct pt_regs *regs, void *offset, void *dest) \ -{ \ - *(type *)dest = (type)regs_get_register(regs, \ - (unsigned int)((unsigned long)offset)); \ -} \ -NOKPROBE_SYMBOL(FETCH_FUNC_NAME(reg, type)); -DEFINE_BASIC_FETCH_FUNCS(reg) -/* No string on the register */ -#define fetch_reg_string NULL -#define fetch_reg_string_size NULL - -#define DEFINE_FETCH_retval(type) \ -void FETCH_FUNC_NAME(retval, type)(struct pt_regs *regs, \ - void *dummy, void *dest) \ -{ \ - *(type *)dest = (type)regs_return_value(regs); \ -} \ -NOKPROBE_SYMBOL(FETCH_FUNC_NAME(retval, type)); -DEFINE_BASIC_FETCH_FUNCS(retval) -/* No string on the retval */ -#define fetch_retval_string NULL -#define fetch_retval_string_size NULL - -/* Dereference memory access function */ -struct deref_fetch_param { - struct fetch_param orig; - long offset; - fetch_func_t fetch; - fetch_func_t fetch_size; -}; - -#define DEFINE_FETCH_deref(type) \ -void FETCH_FUNC_NAME(deref, type)(struct pt_regs *regs, \ - void *data, void *dest) \ -{ \ - struct deref_fetch_param *dprm = data; \ - unsigned long addr; \ - call_fetch(&dprm->orig, regs, &addr); \ - if (addr) { \ - addr += dprm->offset; \ - dprm->fetch(regs, (void *)addr, dest); \ - } else \ - *(type *)dest = 0; \ -} \ -NOKPROBE_SYMBOL(FETCH_FUNC_NAME(deref, type)); -DEFINE_BASIC_FETCH_FUNCS(deref) -DEFINE_FETCH_deref(string) - -void FETCH_FUNC_NAME(deref, string_size)(struct pt_regs *regs, - void *data, void *dest) -{ - struct deref_fetch_param *dprm = data; - unsigned long addr; - - call_fetch(&dprm->orig, regs, &addr); - if (addr && dprm->fetch_size) { - addr += dprm->offset; - dprm->fetch_size(regs, (void *)addr, dest); - } else - *(string_size *)dest = 0; -} -NOKPROBE_SYMBOL(FETCH_FUNC_NAME(deref, string_size)); - -static void update_deref_fetch_param(struct deref_fetch_param *data) -{ - if (CHECK_FETCH_FUNCS(deref, data->orig.fn)) - update_deref_fetch_param(data->orig.data); - else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn)) - update_symbol_cache(data->orig.data); -} -NOKPROBE_SYMBOL(update_deref_fetch_param); - -static void free_deref_fetch_param(struct deref_fetch_param *data) -{ - if (CHECK_FETCH_FUNCS(deref, data->orig.fn)) - free_deref_fetch_param(data->orig.data); - else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn)) - free_symbol_cache(data->orig.data); - kfree(data); -} -NOKPROBE_SYMBOL(free_deref_fetch_param); - -/* Bitfield fetch function */ -struct bitfield_fetch_param { - struct fetch_param orig; - unsigned char hi_shift; - unsigned char low_shift; -}; - -#define DEFINE_FETCH_bitfield(type) \ -void FETCH_FUNC_NAME(bitfield, type)(struct pt_regs *regs, \ - void *data, void *dest) \ -{ \ - struct bitfield_fetch_param *bprm = data; \ - type buf = 0; \ - call_fetch(&bprm->orig, regs, &buf); \ - if (buf) { \ - buf <<= bprm->hi_shift; \ - buf >>= bprm->low_shift; \ - } \ - *(type *)dest = buf; \ -} \ -NOKPROBE_SYMBOL(FETCH_FUNC_NAME(bitfield, type)); -DEFINE_BASIC_FETCH_FUNCS(bitfield) -#define fetch_bitfield_string NULL -#define fetch_bitfield_string_size NULL - -static void -update_bitfield_fetch_param(struct bitfield_fetch_param *data) -{ - /* - * Don't check the bitfield itself, because this must be the - * last fetch function. - */ - if (CHECK_FETCH_FUNCS(deref, data->orig.fn)) - update_deref_fetch_param(data->orig.data); - else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn)) - update_symbol_cache(data->orig.data); -} - -static void -free_bitfield_fetch_param(struct bitfield_fetch_param *data) -{ - /* - * Don't check the bitfield itself, because this must be the - * last fetch function. - */ - if (CHECK_FETCH_FUNCS(deref, data->orig.fn)) - free_deref_fetch_param(data->orig.data); - else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn)) - free_symbol_cache(data->orig.data); - - kfree(data); -} - -void FETCH_FUNC_NAME(comm, string)(struct pt_regs *regs, - void *data, void *dest) -{ - int maxlen = get_rloc_len(*(u32 *)dest); - u8 *dst = get_rloc_data(dest); - long ret; - - if (!maxlen) - return; - - ret = strlcpy(dst, current->comm, maxlen); - *(u32 *)dest = make_data_rloc(ret, get_rloc_offs(*(u32 *)dest)); -} -NOKPROBE_SYMBOL(FETCH_FUNC_NAME(comm, string)); - -void FETCH_FUNC_NAME(comm, string_size)(struct pt_regs *regs, - void *data, void *dest) -{ - *(u32 *)dest = strlen(current->comm) + 1; -} -NOKPROBE_SYMBOL(FETCH_FUNC_NAME(comm, string_size)); - static const struct fetch_type *find_fetch_type(const char *type, const struct fetch_type *ftbl) { @@ -284,37 +116,6 @@ static const struct fetch_type *find_fetch_type(const char *type, return NULL; }
-/* Special function : only accept unsigned long */ -static void fetch_kernel_stack_address(struct pt_regs *regs, void *dummy, void *dest) -{ - *(unsigned long *)dest = kernel_stack_pointer(regs); -} -NOKPROBE_SYMBOL(fetch_kernel_stack_address); - -static void fetch_user_stack_address(struct pt_regs *regs, void *dummy, void *dest) -{ - *(unsigned long *)dest = user_stack_pointer(regs); -} -NOKPROBE_SYMBOL(fetch_user_stack_address); - -static fetch_func_t get_fetch_size_function(const struct fetch_type *type, - fetch_func_t orig_fn, - const struct fetch_type *ftbl) -{ - int i; - - if (type != &ftbl[FETCH_TYPE_STRING]) - return NULL; /* Only string type needs size function */ - - for (i = 0; i < FETCH_MTD_END; i++) - if (type->fetch[i] == orig_fn) - return ftbl[FETCH_TYPE_STRSIZE].fetch[i]; - - WARN_ON(1); /* This should not happen */ - - return NULL; -} - /* Split symbol and offset. */ int traceprobe_split_symbol_offset(char *symbol, long *offset) { @@ -339,7 +140,7 @@ int traceprobe_split_symbol_offset(char *symbol, long *offset) #define PARAM_MAX_STACK (THREAD_SIZE / sizeof(unsigned long))
static int parse_probe_vars(char *arg, const struct fetch_type *t, - struct fetch_param *f, bool is_return, + struct fetch_insn *code, bool is_return, bool is_kprobe) { int ret = 0; @@ -347,33 +148,24 @@ static int parse_probe_vars(char *arg, const struct fetch_type *t,
if (strcmp(arg, "retval") == 0) { if (is_return) - f->fn = t->fetch[FETCH_MTD_retval]; + code->op = FETCH_OP_RETVAL; else ret = -EINVAL; } else if (strncmp(arg, "stack", 5) == 0) { if (arg[5] == '\0') { - if (strcmp(t->name, DEFAULT_FETCH_TYPE_STR)) - return -EINVAL; - - if (is_kprobe) - f->fn = fetch_kernel_stack_address; - else - f->fn = fetch_user_stack_address; + code->op = FETCH_OP_STACKP; } else if (isdigit(arg[5])) { ret = kstrtoul(arg + 5, 10, ¶m); if (ret || (is_kprobe && param > PARAM_MAX_STACK)) ret = -EINVAL; else { - f->fn = t->fetch[FETCH_MTD_stack]; - f->data = (void *)param; + code->op = FETCH_OP_STACK; + code->param = (unsigned int)param; } } else ret = -EINVAL; } else if (strcmp(arg, "comm") == 0) { - if (strcmp(t->name, "string") != 0 && - strcmp(t->name, "string_size") != 0) - return -EINVAL; - f->fn = t->fetch[FETCH_MTD_comm]; + code->op = FETCH_OP_COMM; } else ret = -EINVAL;
@@ -381,10 +173,13 @@ static int parse_probe_vars(char *arg, const struct fetch_type *t, }
/* Recursive argument parser */ -static int parse_probe_arg(char *arg, const struct fetch_type *t, - struct fetch_param *f, bool is_return, bool is_kprobe, - const struct fetch_type *ftbl) +static int +parse_probe_arg(char *arg, const struct fetch_type *type, + struct fetch_insn **pcode, struct fetch_insn *end, + bool is_return, bool is_kprobe, + const struct fetch_type *ftbl) { + struct fetch_insn *code = *pcode; unsigned long param; long offset; char *tmp; @@ -392,14 +187,15 @@ static int parse_probe_arg(char *arg, const struct fetch_type *t,
switch (arg[0]) { case '$': - ret = parse_probe_vars(arg + 1, t, f, is_return, is_kprobe); + ret = parse_probe_vars(arg + 1, type, code, + is_return, is_kprobe); break;
case '%': /* named register */ ret = regs_query_register_offset(arg + 1); if (ret >= 0) { - f->fn = t->fetch[FETCH_MTD_reg]; - f->data = (void *)(unsigned long)ret; + code->op = FETCH_OP_REG; + code->param = (unsigned int)ret; ret = 0; } break; @@ -409,9 +205,9 @@ static int parse_probe_arg(char *arg, const struct fetch_type *t, ret = kstrtoul(arg + 1, 0, ¶m); if (ret) break; - - f->fn = t->fetch[FETCH_MTD_memory]; - f->data = (void *)param; + /* load address */ + code->op = FETCH_OP_IMM; + code->immediate = param; } else if (arg[1] == '+') { /* kprobes don't support file offsets */ if (is_kprobe) @@ -421,8 +217,8 @@ static int parse_probe_arg(char *arg, const struct fetch_type *t, if (ret) break;
- f->fn = t->fetch[FETCH_MTD_file_offset]; - f->data = (void *)offset; + code->op = FETCH_OP_FOFFS; + code->immediate = (unsigned long)offset; // imm64? } else { /* uprobes don't support symbols */ if (!is_kprobe) @@ -432,10 +228,19 @@ static int parse_probe_arg(char *arg, const struct fetch_type *t, if (ret) break;
- f->data = alloc_symbol_cache(arg + 1, offset); - if (f->data) - f->fn = t->fetch[FETCH_MTD_symbol]; + code->op = FETCH_OP_IMM; + code->immediate = + (unsigned long)kallsyms_lookup_name(arg + 1); + if (!code->immediate) + return -ENOENT; + code->immediate += offset; } + /* These are fetching from memory */ + if (++code == end) + return -E2BIG; + *pcode = code; + code->op = FETCH_OP_DEREF; + code->offset = offset; break;
case '+': /* deref memory */ @@ -443,11 +248,10 @@ static int parse_probe_arg(char *arg, const struct fetch_type *t, case '-': tmp = strchr(arg, '('); if (!tmp) - break; + return -EINVAL;
*tmp = '\0'; ret = kstrtol(arg, 0, &offset); - if (ret) break;
@@ -455,36 +259,29 @@ static int parse_probe_arg(char *arg, const struct fetch_type *t, tmp = strrchr(arg, ')');
if (tmp) { - struct deref_fetch_param *dprm; - const struct fetch_type *t2; + const struct fetch_type *t2;
t2 = find_fetch_type(NULL, ftbl); *tmp = '\0'; - dprm = kzalloc(sizeof(struct deref_fetch_param), GFP_KERNEL); - - if (!dprm) - return -ENOMEM; - - dprm->offset = offset; - dprm->fetch = t->fetch[FETCH_MTD_memory]; - dprm->fetch_size = get_fetch_size_function(t, - dprm->fetch, ftbl); - ret = parse_probe_arg(arg, t2, &dprm->orig, is_return, - is_kprobe, ftbl); + ret = parse_probe_arg(arg, t2, &code, end, is_return, + is_kprobe, ftbl); if (ret) - kfree(dprm); - else { - f->fn = t->fetch[FETCH_MTD_deref]; - f->data = (void *)dprm; - } + break; + if (code->op == FETCH_OP_COMM) + return -EINVAL; + if (++code == end) + return -E2BIG; + *pcode = code; + + code->op = FETCH_OP_DEREF; + code->offset = offset; } break; } - if (!ret && !f->fn) { /* Parsed, but do not find fetch method */ - pr_info("%s type has no corresponding fetch method.\n", t->name); + if (!ret && code->op == FETCH_OP_NOP) { + /* Parsed, but do not find fetch method */ ret = -EINVAL; } - return ret; }
@@ -493,22 +290,15 @@ static int parse_probe_arg(char *arg, const struct fetch_type *t, /* Bitfield type needs to be parsed into a fetch function */ static int __parse_bitfield_probe_arg(const char *bf, const struct fetch_type *t, - struct fetch_param *f) + struct fetch_insn **pcode) { - struct bitfield_fetch_param *bprm; + struct fetch_insn *code = *pcode; unsigned long bw, bo; char *tail;
if (*bf != 'b') return 0;
- bprm = kzalloc(sizeof(*bprm), GFP_KERNEL); - if (!bprm) - return -ENOMEM; - - bprm->orig = *f; - f->fn = t->fetch[FETCH_MTD_bitfield]; - f->data = (void *)bprm; bw = simple_strtoul(bf + 1, &tail, 0); /* Use simple one */
if (bw == 0 || *tail != '@') @@ -519,9 +309,15 @@ static int __parse_bitfield_probe_arg(const char *bf,
if (tail == bf || *tail != '/') return -EINVAL; + code++; + if (code->op != FETCH_OP_NOP) + return -E2BIG; + *pcode = code;
- bprm->hi_shift = BYTES_TO_BITS(t->size) - (bw + bo); - bprm->low_shift = bprm->hi_shift + bo; + code->op = FETCH_OP_MOD_BF; + code->lshift = BYTES_TO_BITS(t->size) - (bw + bo); + code->rshift = BYTES_TO_BITS(t->size) - bw; + code->basesize = t->size;
return (BYTES_TO_BITS(t->size) < (bw + bo)) ? -EINVAL : 0; } @@ -531,6 +327,7 @@ int traceprobe_parse_probe_arg(char *arg, ssize_t *size, struct probe_arg *parg, bool is_return, bool is_kprobe, const struct fetch_type *ftbl) { + struct fetch_insn *code, *tmp = NULL; const char *t; int ret;
@@ -561,18 +358,60 @@ int traceprobe_parse_probe_arg(char *arg, ssize_t *size, } parg->offset = *size; *size += parg->type->size; - ret = parse_probe_arg(arg, parg->type, &parg->fetch, is_return, - is_kprobe, ftbl); - - if (ret >= 0 && t != NULL) - ret = __parse_bitfield_probe_arg(t, parg->type, &parg->fetch);
- if (ret >= 0) { - parg->fetch_size.fn = get_fetch_size_function(parg->type, - parg->fetch.fn, - ftbl); - parg->fetch_size.data = parg->fetch.data; + code = tmp = kzalloc(sizeof(*code) * FETCH_INSN_MAX, GFP_KERNEL); + if (!code) + return -ENOMEM; + code[FETCH_INSN_MAX - 1].op = FETCH_OP_END; + + ret = parse_probe_arg(arg, parg->type, &code, &code[FETCH_INSN_MAX - 1], + is_return, is_kprobe, ftbl); + if (ret) + goto fail; + + /* Store operation */ + if (!strcmp(parg->type->name, "string")) { + if (code->op != FETCH_OP_DEREF && code->op != FETCH_OP_IMM && + code->op != FETCH_OP_COMM) { + pr_info("string only accepts memory or address.\n"); + ret = -EINVAL; + goto fail; + } + /* Since IMM or COMM must be the 1st insn, this is safe */ + if (code->op == FETCH_OP_IMM || code->op == FETCH_OP_COMM) + code++; + code->op = FETCH_OP_ST_STRING; /* In DEREF case, replace it */ + parg->dynamic = true; + } else if (code->op == FETCH_OP_DEREF) { + code->op = FETCH_OP_ST_MEM; + code->size = parg->type->size; + } else { + code++; + if (code->op != FETCH_OP_NOP) { + ret = -E2BIG; + goto fail; + } + code->op = FETCH_OP_ST_RAW; + code->size = parg->type->size; + } + /* Modify operation */ + if (t != NULL) { + ret = __parse_bitfield_probe_arg(t, parg->type, &code); + if (ret) + goto fail; } + code++; + code->op = FETCH_OP_END; + + /* Shrink down the code buffer */ + parg->code = kzalloc(sizeof(*code) * (code - tmp + 1), GFP_KERNEL); + if (!parg->code) + ret = -ENOMEM; + else + memcpy(parg->code, tmp, sizeof(*code) * (code - tmp + 1)); + +fail: + kfree(tmp);
return ret; } @@ -594,25 +433,9 @@ int traceprobe_conflict_field_name(const char *name, return 0; }
-void traceprobe_update_arg(struct probe_arg *arg) -{ - if (CHECK_FETCH_FUNCS(bitfield, arg->fetch.fn)) - update_bitfield_fetch_param(arg->fetch.data); - else if (CHECK_FETCH_FUNCS(deref, arg->fetch.fn)) - update_deref_fetch_param(arg->fetch.data); - else if (CHECK_FETCH_FUNCS(symbol, arg->fetch.fn)) - update_symbol_cache(arg->fetch.data); -} - void traceprobe_free_probe_arg(struct probe_arg *arg) { - if (CHECK_FETCH_FUNCS(bitfield, arg->fetch.fn)) - free_bitfield_fetch_param(arg->fetch.data); - else if (CHECK_FETCH_FUNCS(deref, arg->fetch.fn)) - free_deref_fetch_param(arg->fetch.data); - else if (CHECK_FETCH_FUNCS(symbol, arg->fetch.fn)) - free_symbol_cache(arg->fetch.data); - + kfree(arg->code); kfree(arg->name); kfree(arg->comm); } diff --git a/kernel/trace/trace_probe.h b/kernel/trace/trace_probe.h index de928052926b..9d9de7535d06 100644 --- a/kernel/trace/trace_probe.h +++ b/kernel/trace/trace_probe.h @@ -91,25 +91,50 @@ static nokprobe_inline void *get_loc_data(u32 *dl, void *ent) return (u8 *)ent + get_rloc_offs(*dl); }
-/* Data fetch function type */ -typedef void (*fetch_func_t)(struct pt_regs *, void *, void *); /* Printing function type */ typedef int (*print_type_func_t)(struct trace_seq *, void *, void *);
-/* Fetch types */ -enum { - FETCH_MTD_reg = 0, - FETCH_MTD_stack, - FETCH_MTD_retval, - FETCH_MTD_comm, - FETCH_MTD_memory, - FETCH_MTD_symbol, - FETCH_MTD_deref, - FETCH_MTD_bitfield, - FETCH_MTD_file_offset, - FETCH_MTD_END, +enum fetch_op { + FETCH_OP_NOP = 0, + // Stage 1 (load) ops + FETCH_OP_REG, /* Register : .param = offset */ + FETCH_OP_STACK, /* Stack : .param = index */ + FETCH_OP_STACKP, /* Stack pointer */ + FETCH_OP_RETVAL, /* Return value */ + FETCH_OP_IMM, /* Immediate : .immediate */ + FETCH_OP_COMM, /* Current comm */ + FETCH_OP_FOFFS, /* File offset: .immediate */ + // Stage 2 (dereference) op + FETCH_OP_DEREF, /* Dereference: .offset */ + // Stage 3 (store) ops + FETCH_OP_ST_RAW, /* Raw: .size */ + FETCH_OP_ST_MEM, /* Mem: .offset, .size */ + FETCH_OP_ST_STRING, /* String: .offset, .size */ + // Stage 4 (modify) op + FETCH_OP_MOD_BF, /* Bitfield: .basesize, .lshift, .rshift */ + FETCH_OP_END, };
+struct fetch_insn { + enum fetch_op op; + union { + unsigned int param; + struct { + unsigned int size; + int offset; + }; + struct { + unsigned char basesize; + unsigned char lshift; + unsigned char rshift; + }; + unsigned long immediate; + }; +}; + +/* fetch + deref*N + store + mod + end <= 16, this allows N=12, enough */ +#define FETCH_INSN_MAX 16 + /* Fetch type information table */ struct fetch_type { const char *name; /* Name of type */ @@ -118,13 +143,6 @@ struct fetch_type { print_type_func_t print; /* Print functions */ const char *fmt; /* Fromat string */ const char *fmttype; /* Name in format file */ - /* Fetch functions */ - fetch_func_t fetch[FETCH_MTD_END]; -}; - -struct fetch_param { - fetch_func_t fn; - void *data; };
/* For defining macros, define string/string_size types */ @@ -154,66 +172,12 @@ DECLARE_BASIC_PRINT_TYPE_FUNC(x64);
DECLARE_BASIC_PRINT_TYPE_FUNC(string);
-#define FETCH_FUNC_NAME(method, type) fetch_##method##_##type - -/* Declare macro for basic types */ -#define DECLARE_FETCH_FUNC(method, type) \ -extern void FETCH_FUNC_NAME(method, type)(struct pt_regs *regs, \ - void *data, void *dest) - -#define DECLARE_BASIC_FETCH_FUNCS(method) \ -DECLARE_FETCH_FUNC(method, u8); \ -DECLARE_FETCH_FUNC(method, u16); \ -DECLARE_FETCH_FUNC(method, u32); \ -DECLARE_FETCH_FUNC(method, u64) - -DECLARE_BASIC_FETCH_FUNCS(reg); -#define fetch_reg_string NULL -#define fetch_reg_string_size NULL - -DECLARE_BASIC_FETCH_FUNCS(retval); -#define fetch_retval_string NULL -#define fetch_retval_string_size NULL - -DECLARE_BASIC_FETCH_FUNCS(symbol); -DECLARE_FETCH_FUNC(symbol, string); -DECLARE_FETCH_FUNC(symbol, string_size); - -DECLARE_BASIC_FETCH_FUNCS(deref); -DECLARE_FETCH_FUNC(deref, string); -DECLARE_FETCH_FUNC(deref, string_size); - -DECLARE_BASIC_FETCH_FUNCS(bitfield); -#define fetch_bitfield_string NULL -#define fetch_bitfield_string_size NULL - -/* comm only makes sense as a string */ -#define fetch_comm_u8 NULL -#define fetch_comm_u16 NULL -#define fetch_comm_u32 NULL -#define fetch_comm_u64 NULL -DECLARE_FETCH_FUNC(comm, string); -DECLARE_FETCH_FUNC(comm, string_size); - -/* - * Define macro for basic types - we don't need to define s* types, because - * we have to care only about bitwidth at recording time. - */ -#define DEFINE_BASIC_FETCH_FUNCS(method) \ -DEFINE_FETCH_##method(u8) \ -DEFINE_FETCH_##method(u16) \ -DEFINE_FETCH_##method(u32) \ -DEFINE_FETCH_##method(u64) - /* Default (unsigned long) fetch type */ #define __DEFAULT_FETCH_TYPE(t) x##t #define _DEFAULT_FETCH_TYPE(t) __DEFAULT_FETCH_TYPE(t) #define DEFAULT_FETCH_TYPE _DEFAULT_FETCH_TYPE(BITS_PER_LONG) #define DEFAULT_FETCH_TYPE_STR __stringify(DEFAULT_FETCH_TYPE)
-#define ASSIGN_FETCH_FUNC(method, type) \ - [FETCH_MTD_##method] = FETCH_FUNC_NAME(method, type) - #define __ASSIGN_FETCH_TYPE(_name, ptype, ftype, _size, sign, _fmttype) \ {.name = _name, \ .size = _size, \ @@ -221,17 +185,6 @@ DEFINE_FETCH_##method(u64) .print = PRINT_TYPE_FUNC_NAME(ptype), \ .fmt = PRINT_TYPE_FMT_NAME(ptype), \ .fmttype = _fmttype, \ - .fetch = { \ -ASSIGN_FETCH_FUNC(reg, ftype), \ -ASSIGN_FETCH_FUNC(stack, ftype), \ -ASSIGN_FETCH_FUNC(retval, ftype), \ -ASSIGN_FETCH_FUNC(comm, ftype), \ -ASSIGN_FETCH_FUNC(memory, ftype), \ -ASSIGN_FETCH_FUNC(symbol, ftype), \ -ASSIGN_FETCH_FUNC(deref, ftype), \ -ASSIGN_FETCH_FUNC(bitfield, ftype), \ -ASSIGN_FETCH_FUNC(file_offset, ftype), \ - } \ }
#define ASSIGN_FETCH_TYPE(ptype, ftype, sign) \ @@ -243,42 +196,13 @@ ASSIGN_FETCH_FUNC(file_offset, ftype), \
#define ASSIGN_FETCH_TYPE_END {}
-#define FETCH_TYPE_STRING 0 -#define FETCH_TYPE_STRSIZE 1 +#define FETCH_TYPE_STRING 0 +#define FETCH_TYPE_STRSIZE 1
#ifdef CONFIG_KPROBE_EVENTS -struct symbol_cache; -unsigned long update_symbol_cache(struct symbol_cache *sc); -void free_symbol_cache(struct symbol_cache *sc); -struct symbol_cache *alloc_symbol_cache(const char *sym, long offset); bool trace_kprobe_on_func_entry(struct trace_event_call *call); bool trace_kprobe_error_injectable(struct trace_event_call *call); #else -/* uprobes do not support symbol fetch methods */ -#define fetch_symbol_u8 NULL -#define fetch_symbol_u16 NULL -#define fetch_symbol_u32 NULL -#define fetch_symbol_u64 NULL -#define fetch_symbol_string NULL -#define fetch_symbol_string_size NULL - -struct symbol_cache { -}; -static inline unsigned long __used update_symbol_cache(struct symbol_cache *sc) -{ - return 0; -} - -static inline void __used free_symbol_cache(struct symbol_cache *sc) -{ -} - -static inline struct symbol_cache * __used -alloc_symbol_cache(const char *sym, long offset) -{ - return NULL; -} - static inline bool trace_kprobe_on_func_entry(struct trace_event_call *call) { return false; @@ -291,8 +215,8 @@ static inline bool trace_kprobe_error_injectable(struct trace_event_call *call) #endif /* CONFIG_KPROBE_EVENTS */
struct probe_arg { - struct fetch_param fetch; - struct fetch_param fetch_size; + struct fetch_insn *code; + bool dynamic;/* Dynamic array (string) is used */ unsigned int offset; /* Offset from argument entry */ const char *name; /* Name of this argument */ const char *comm; /* Command of this argument */ @@ -324,12 +248,6 @@ static inline bool trace_probe_is_registered(struct trace_probe *tp) return !!(tp->flags & TP_FLAG_REGISTERED); }
-static nokprobe_inline void call_fetch(struct fetch_param *fprm, - struct pt_regs *regs, void *dest) -{ - return fprm->fn(regs, fprm->data, dest); -} - /* Check the name is good for event/group/fields */ static inline bool is_good_name(const char *name) { @@ -366,68 +284,6 @@ extern void traceprobe_free_probe_arg(struct probe_arg *arg);
extern int traceprobe_split_symbol_offset(char *symbol, long *offset);
-/* Sum up total data length for dynamic arraies (strings) */ -static nokprobe_inline int -__get_data_size(struct trace_probe *tp, struct pt_regs *regs) -{ - int i, ret = 0; - u32 len; - - for (i = 0; i < tp->nr_args; i++) - if (unlikely(tp->args[i].fetch_size.fn)) { - call_fetch(&tp->args[i].fetch_size, regs, &len); - ret += len; - } - - return ret; -} - -/* Store the value of each argument */ -static nokprobe_inline void -store_trace_args(int ent_size, struct trace_probe *tp, struct pt_regs *regs, - u8 *data, int maxlen) -{ - int i; - u32 end = tp->size; - u32 *dl; /* Data (relative) location */ - - for (i = 0; i < tp->nr_args; i++) { - if (unlikely(tp->args[i].fetch_size.fn)) { - /* - * First, we set the relative location and - * maximum data length to *dl - */ - dl = (u32 *)(data + tp->args[i].offset); - *dl = make_data_rloc(maxlen, end - tp->args[i].offset); - /* Then try to fetch string or dynamic array data */ - call_fetch(&tp->args[i].fetch, regs, dl); - /* Reduce maximum length */ - end += get_rloc_len(*dl); - maxlen -= get_rloc_len(*dl); - /* Trick here, convert data_rloc to data_loc */ - *dl = convert_rloc_to_loc(*dl, - ent_size + tp->args[i].offset); - } else - /* Just fetching data normally */ - call_fetch(&tp->args[i].fetch, regs, - data + tp->args[i].offset); - } -} - -static inline int -print_probe_args(struct trace_seq *s, struct probe_arg *args, int nr_args, - u8 *data, void *field) -{ - int i; - - for (i = 0; i < nr_args; i++) { - trace_seq_printf(s, " %s=", args[i].name); - if (!args[i].type->print(s, data + args[i].offset, field)) - return -ENOMEM; - } - return 0; -} - extern int set_print_fmt(struct trace_probe *tp, bool is_return);
#ifdef CONFIG_PERF_EVENTS diff --git a/kernel/trace/trace_probe_tmpl.h b/kernel/trace/trace_probe_tmpl.h new file mode 100644 index 000000000000..c8a5272abf01 --- /dev/null +++ b/kernel/trace/trace_probe_tmpl.h @@ -0,0 +1,120 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Traceprobe fetch helper inlines + */ + +static nokprobe_inline void +fetch_store_raw(unsigned long val, struct fetch_insn *code, void *buf) +{ + switch (code->size) { + case 1: + *(u8 *)buf = (u8)val; + break; + case 2: + *(u16 *)buf = (u16)val; + break; + case 4: + *(u32 *)buf = (u32)val; + break; + case 8: + //TBD: 32bit signed + *(u64 *)buf = (u64)val; + break; + default: + *(unsigned long *)buf = val; + } +} + +static nokprobe_inline void +fetch_apply_bitfield(struct fetch_insn *code, void *buf) +{ + switch (code->basesize) { + case 1: + *(u8 *)buf <<= code->lshift; + *(u8 *)buf >>= code->rshift; + break; + case 2: + *(u16 *)buf <<= code->lshift; + *(u16 *)buf >>= code->rshift; + break; + case 4: + *(u32 *)buf <<= code->lshift; + *(u32 *)buf >>= code->rshift; + break; + case 8: + *(u64 *)buf <<= code->lshift; + *(u64 *)buf >>= code->rshift; + break; + } +} + +/* Define this for each callsite */ +static int +process_fetch_insn(struct fetch_insn *code, struct pt_regs *regs, + void *dest, bool pre); + +/* Sum up total data length for dynamic arraies (strings) */ +static nokprobe_inline int +__get_data_size(struct trace_probe *tp, struct pt_regs *regs) +{ + struct probe_arg *arg; + int i, ret = 0; + u32 len; + + for (i = 0; i < tp->nr_args; i++) { + arg = tp->args + i; + if (unlikely(arg->dynamic)) { + process_fetch_insn(arg->code, regs, &len, true); + ret += len; + } + } + + return ret; +} + +/* Store the value of each argument */ +static nokprobe_inline void +store_trace_args(int ent_size, struct trace_probe *tp, struct pt_regs *regs, + u8 *data, int maxlen) +{ + struct probe_arg *arg; + u32 end = tp->size; + u32 *dl; /* Data (relative) location */ + int i; + + for (i = 0; i < tp->nr_args; i++) { + arg = tp->args + i; + if (unlikely(arg->dynamic)) { + /* + * First, we set the relative location and + * maximum data length to *dl + */ + dl = (u32 *)(data + arg->offset); + *dl = make_data_rloc(maxlen, end - arg->offset); + /* Then try to fetch string or dynamic array data */ + process_fetch_insn(arg->code, regs, dl, false); + /* Reduce maximum length */ + end += get_rloc_len(*dl); + maxlen -= get_rloc_len(*dl); + /* Trick here, convert data_rloc to data_loc */ + *dl = convert_rloc_to_loc(*dl, ent_size + arg->offset); + } else + /* Just fetching data normally */ + process_fetch_insn(arg->code, regs, data + arg->offset, + false); + } +} + +static inline int +print_probe_args(struct trace_seq *s, struct probe_arg *args, int nr_args, + u8 *data, void *field) +{ + int i; + + for (i = 0; i < nr_args; i++) { + trace_seq_printf(s, " %s=", args[i].name); + if (!args[i].type->print(s, data + args[i].offset, field)) + return -ENOMEM; + } + return 0; +} diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c index 887da2bb63aa..e1bc33c5cd99 100644 --- a/kernel/trace/trace_uprobe.c +++ b/kernel/trace/trace_uprobe.c @@ -27,6 +27,7 @@ #include <linux/rculist.h>
#include "trace_probe.h" +#include "trace_probe_tmpl.h"
#define UPROBE_EVENT_SYSTEM "uprobes"
@@ -109,37 +110,19 @@ static unsigned long get_user_stack_nth(struct pt_regs *regs, unsigned int n) /* * Uprobes-specific fetch functions */ -#define DEFINE_FETCH_stack(type) \ -static void FETCH_FUNC_NAME(stack, type)(struct pt_regs *regs, \ - void *offset, void *dest) \ -{ \ - *(type *)dest = (type)get_user_stack_nth(regs, \ - ((unsigned long)offset)); \ -} -DEFINE_BASIC_FETCH_FUNCS(stack) -/* No string on the stack entry */ -#define fetch_stack_string NULL -#define fetch_stack_string_size NULL - -#define DEFINE_FETCH_memory(type) \ -static void FETCH_FUNC_NAME(memory, type)(struct pt_regs *regs, \ - void *addr, void *dest) \ -{ \ - type retval; \ - void __user *vaddr = (void __force __user *) addr; \ - \ - if (copy_from_user(&retval, vaddr, sizeof(type))) \ - *(type *)dest = 0; \ - else \ - *(type *) dest = retval; \ +static nokprobe_inline int +probe_user_read(void *dest, void *src, size_t size) +{ + void __user *vaddr = (void __force __user *)src; + + return copy_from_user(dest, vaddr, size); } -DEFINE_BASIC_FETCH_FUNCS(memory) /* * Fetch a null-terminated string. Caller MUST set *(u32 *)dest with max * length and relative data location. */ -static void FETCH_FUNC_NAME(memory, string)(struct pt_regs *regs, - void *addr, void *dest) +static nokprobe_inline void +fetch_store_string(unsigned long addr, void *dest) { long ret; u32 rloc = *(u32 *)dest; @@ -160,8 +143,9 @@ static void FETCH_FUNC_NAME(memory, string)(struct pt_regs *regs, } }
-static void FETCH_FUNC_NAME(memory, string_size)(struct pt_regs *regs, - void *addr, void *dest) +/* Return the length of string -- including null terminal byte */ +static nokprobe_inline void +fetch_store_strlen(unsigned long addr, void *dest) { int len; void __user *vaddr = (void __force __user *) addr; @@ -174,7 +158,7 @@ static void FETCH_FUNC_NAME(memory, string_size)(struct pt_regs *regs, *(u32 *)dest = len; }
-static unsigned long translate_user_vaddr(void *file_offset) +static unsigned long translate_user_vaddr(unsigned long file_offset) { unsigned long base_addr; struct uprobe_dispatch_data *udd; @@ -182,21 +166,9 @@ static unsigned long translate_user_vaddr(void *file_offset) udd = (void *) current->utask->vaddr;
base_addr = udd->bp_addr - udd->tu->offset; - return base_addr + (unsigned long)file_offset; + return base_addr + file_offset; }
-#define DEFINE_FETCH_file_offset(type) \ -static void FETCH_FUNC_NAME(file_offset, type)(struct pt_regs *regs, \ - void *offset, void *dest)\ -{ \ - void *vaddr = (void *)translate_user_vaddr(offset); \ - \ - FETCH_FUNC_NAME(memory, type)(regs, vaddr, dest); \ -} -DEFINE_BASIC_FETCH_FUNCS(file_offset) -DEFINE_FETCH_file_offset(string) -DEFINE_FETCH_file_offset(string_size) - /* Fetch type information table */ static const struct fetch_type uprobes_fetch_type_table[] = { /* Special types */ @@ -221,6 +193,77 @@ static const struct fetch_type uprobes_fetch_type_table[] = { ASSIGN_FETCH_TYPE_END };
+/* Note that we don't verify it, since the code does not come from user space */ +static int +process_fetch_insn(struct fetch_insn *code, struct pt_regs *regs, void *dest, + bool pre) +{ + unsigned long val; + int ret; + + /* 1st stage: get value from context */ + switch (code->op) { + case FETCH_OP_REG: + val = regs_get_register(regs, code->param); + break; + case FETCH_OP_STACK: + val = get_user_stack_nth(regs, code->param); + break; + case FETCH_OP_STACKP: + val = user_stack_pointer(regs); + break; + case FETCH_OP_RETVAL: + val = regs_return_value(regs); + break; + case FETCH_OP_IMM: + val = code->immediate; + break; + case FETCH_OP_FOFFS: + val = translate_user_vaddr(code->immediate); + break; + default: + return -EILSEQ; + } + code++; + + /* 2nd stage: dereference memory if needed */ + while (code->op == FETCH_OP_DEREF) { + ret = probe_user_read(&val, (void *)val + code->offset, + sizeof(val)); + if (ret) + return ret; + code++; + } + + /* 3rd stage: store value to buffer */ + switch (code->op) { + case FETCH_OP_ST_RAW: + fetch_store_raw(val, code, dest); + break; + case FETCH_OP_ST_MEM: + probe_user_read(dest, (void *)val + code->offset, code->size); + break; + case FETCH_OP_ST_STRING: + if (pre) + fetch_store_strlen(val + code->offset, dest); + else + fetch_store_string(val + code->offset, dest); + break; + default: + return -EILSEQ; + } + code++; + + /* 4th stage: modify stored value if needed */ + if (code->op == FETCH_OP_MOD_BF) { + fetch_apply_bitfield(code, dest); + code++; + } + + return code->op == FETCH_OP_END ? 0 : -EILSEQ; +} +NOKPROBE_SYMBOL(process_fetch_insn) + static inline void init_trace_uprobe_filter(struct trace_uprobe_filter *filter) { rwlock_init(&filter->rwlock);
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Unify {k,u}probe_fetch_type_table to probe_fetch_type_table because the main difference of those type tables (fetcharg methods) are gone. Now we can consolidate it.
Signed-off-by: Masami Hiramatsu mhiramat@kernel.org --- kernel/trace/trace_kprobe.c | 27 +--------------------- kernel/trace/trace_probe.c | 54 +++++++++++++++++++++++++++++-------------- kernel/trace/trace_probe.h | 6 +---- kernel/trace/trace_uprobe.c | 27 +--------------------- 4 files changed, 39 insertions(+), 75 deletions(-)
diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c index 8423815ff986..4caf019b5917 100644 --- a/kernel/trace/trace_kprobe.c +++ b/kernel/trace/trace_kprobe.c @@ -122,30 +122,6 @@ static int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs); static int kretprobe_dispatcher(struct kretprobe_instance *ri, struct pt_regs *regs);
-/* Fetch type information table */ -static const struct fetch_type kprobes_fetch_type_table[] = { - /* Special types */ - [FETCH_TYPE_STRING] = __ASSIGN_FETCH_TYPE("string", string, string, - sizeof(u32), 1, "__data_loc char[]"), - [FETCH_TYPE_STRSIZE] = __ASSIGN_FETCH_TYPE("string_size", u32, - string_size, sizeof(u32), 0, "u32"), - /* Basic types */ - ASSIGN_FETCH_TYPE(u8, u8, 0), - ASSIGN_FETCH_TYPE(u16, u16, 0), - ASSIGN_FETCH_TYPE(u32, u32, 0), - ASSIGN_FETCH_TYPE(u64, u64, 0), - ASSIGN_FETCH_TYPE(s8, u8, 1), - ASSIGN_FETCH_TYPE(s16, u16, 1), - ASSIGN_FETCH_TYPE(s32, u32, 1), - ASSIGN_FETCH_TYPE(s64, u64, 1), - ASSIGN_FETCH_TYPE_ALIAS(x8, u8, u8, 0), - ASSIGN_FETCH_TYPE_ALIAS(x16, u16, u16, 0), - ASSIGN_FETCH_TYPE_ALIAS(x32, u32, u32, 0), - ASSIGN_FETCH_TYPE_ALIAS(x64, u64, u64, 0), - - ASSIGN_FETCH_TYPE_END -}; - /* * Allocate new trace_probe and initialize it (including kprobes). */ @@ -674,8 +650,7 @@ static int create_trace_kprobe(int argc, char **argv)
/* Parse fetch argument */ ret = traceprobe_parse_probe_arg(arg, &tk->tp.size, parg, - is_return, true, - kprobes_fetch_type_table); + is_return, true); if (ret) { pr_info("Parse error at argument[%d]. (%d)\n", i, ret); goto error; diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c index a7e36606718a..9ffc07c7c949 100644 --- a/kernel/trace/trace_probe.c +++ b/kernel/trace/trace_probe.c @@ -73,8 +73,29 @@ int PRINT_TYPE_FUNC_NAME(string)(struct trace_seq *s, void *data, void *ent)
const char PRINT_TYPE_FMT_NAME(string)[] = "\"%s\"";
-static const struct fetch_type *find_fetch_type(const char *type, - const struct fetch_type *ftbl) +/* Fetch type information table */ +static const struct fetch_type probe_fetch_types[] = { + /* Special types */ + __ASSIGN_FETCH_TYPE("string", string, string, sizeof(u32), 1, + "__data_loc char[]"), + /* Basic types */ + ASSIGN_FETCH_TYPE(u8, u8, 0), + ASSIGN_FETCH_TYPE(u16, u16, 0), + ASSIGN_FETCH_TYPE(u32, u32, 0), + ASSIGN_FETCH_TYPE(u64, u64, 0), + ASSIGN_FETCH_TYPE(s8, u8, 1), + ASSIGN_FETCH_TYPE(s16, u16, 1), + ASSIGN_FETCH_TYPE(s32, u32, 1), + ASSIGN_FETCH_TYPE(s64, u64, 1), + ASSIGN_FETCH_TYPE_ALIAS(x8, u8, u8, 0), + ASSIGN_FETCH_TYPE_ALIAS(x16, u16, u16, 0), + ASSIGN_FETCH_TYPE_ALIAS(x32, u32, u32, 0), + ASSIGN_FETCH_TYPE_ALIAS(x64, u64, u64, 0), + + ASSIGN_FETCH_TYPE_END +}; + +static const struct fetch_type *find_fetch_type(const char *type) { int i;
@@ -95,21 +116,21 @@ static const struct fetch_type *find_fetch_type(const char *type,
switch (bs) { case 8: - return find_fetch_type("u8", ftbl); + return find_fetch_type("u8"); case 16: - return find_fetch_type("u16", ftbl); + return find_fetch_type("u16"); case 32: - return find_fetch_type("u32", ftbl); + return find_fetch_type("u32"); case 64: - return find_fetch_type("u64", ftbl); + return find_fetch_type("u64"); default: goto fail; } }
- for (i = 0; ftbl[i].name; i++) { - if (strcmp(type, ftbl[i].name) == 0) - return &ftbl[i]; + for (i = 0; probe_fetch_types[i].name; i++) { + if (strcmp(type, probe_fetch_types[i].name) == 0) + return &probe_fetch_types[i]; }
fail: @@ -176,8 +197,7 @@ static int parse_probe_vars(char *arg, const struct fetch_type *t, static int parse_probe_arg(char *arg, const struct fetch_type *type, struct fetch_insn **pcode, struct fetch_insn *end, - bool is_return, bool is_kprobe, - const struct fetch_type *ftbl) + bool is_return, bool is_kprobe) { struct fetch_insn *code = *pcode; unsigned long param; @@ -259,12 +279,11 @@ parse_probe_arg(char *arg, const struct fetch_type *type, tmp = strrchr(arg, ')');
if (tmp) { - const struct fetch_type *t2; + const struct fetch_type *t2 = find_fetch_type(NULL);
- t2 = find_fetch_type(NULL, ftbl); *tmp = '\0'; ret = parse_probe_arg(arg, t2, &code, end, is_return, - is_kprobe, ftbl); + is_kprobe); if (ret) break; if (code->op == FETCH_OP_COMM) @@ -324,8 +343,7 @@ static int __parse_bitfield_probe_arg(const char *bf,
/* String length checking wrapper */ int traceprobe_parse_probe_arg(char *arg, ssize_t *size, - struct probe_arg *parg, bool is_return, bool is_kprobe, - const struct fetch_type *ftbl) + struct probe_arg *parg, bool is_return, bool is_kprobe) { struct fetch_insn *code, *tmp = NULL; const char *t; @@ -351,7 +369,7 @@ int traceprobe_parse_probe_arg(char *arg, ssize_t *size, */ if (!t && strcmp(arg, "$comm") == 0) t = "string"; - parg->type = find_fetch_type(t, ftbl); + parg->type = find_fetch_type(t); if (!parg->type) { pr_info("Unsupported type: %s\n", t); return -EINVAL; @@ -365,7 +383,7 @@ int traceprobe_parse_probe_arg(char *arg, ssize_t *size, code[FETCH_INSN_MAX - 1].op = FETCH_OP_END;
ret = parse_probe_arg(arg, parg->type, &code, &code[FETCH_INSN_MAX - 1], - is_return, is_kprobe, ftbl); + is_return, is_kprobe); if (ret) goto fail;
diff --git a/kernel/trace/trace_probe.h b/kernel/trace/trace_probe.h index 9d9de7535d06..89d853ef5174 100644 --- a/kernel/trace/trace_probe.h +++ b/kernel/trace/trace_probe.h @@ -196,9 +196,6 @@ DECLARE_BASIC_PRINT_TYPE_FUNC(string);
#define ASSIGN_FETCH_TYPE_END {}
-#define FETCH_TYPE_STRING 0 -#define FETCH_TYPE_STRSIZE 1 - #ifdef CONFIG_KPROBE_EVENTS bool trace_kprobe_on_func_entry(struct trace_event_call *call); bool trace_kprobe_error_injectable(struct trace_event_call *call); @@ -273,8 +270,7 @@ find_event_file_link(struct trace_probe *tp, struct trace_event_file *file) }
extern int traceprobe_parse_probe_arg(char *arg, ssize_t *size, - struct probe_arg *parg, bool is_return, bool is_kprobe, - const struct fetch_type *ftbl); + struct probe_arg *parg, bool is_return, bool is_kprobe);
extern int traceprobe_conflict_field_name(const char *name, struct probe_arg *args, int narg); diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c index e1bc33c5cd99..9fc0123c721f 100644 --- a/kernel/trace/trace_uprobe.c +++ b/kernel/trace/trace_uprobe.c @@ -169,30 +169,6 @@ static unsigned long translate_user_vaddr(unsigned long file_offset) return base_addr + file_offset; }
-/* Fetch type information table */ -static const struct fetch_type uprobes_fetch_type_table[] = { - /* Special types */ - [FETCH_TYPE_STRING] = __ASSIGN_FETCH_TYPE("string", string, string, - sizeof(u32), 1, "__data_loc char[]"), - [FETCH_TYPE_STRSIZE] = __ASSIGN_FETCH_TYPE("string_size", u32, - string_size, sizeof(u32), 0, "u32"), - /* Basic types */ - ASSIGN_FETCH_TYPE(u8, u8, 0), - ASSIGN_FETCH_TYPE(u16, u16, 0), - ASSIGN_FETCH_TYPE(u32, u32, 0), - ASSIGN_FETCH_TYPE(u64, u64, 0), - ASSIGN_FETCH_TYPE(s8, u8, 1), - ASSIGN_FETCH_TYPE(s16, u16, 1), - ASSIGN_FETCH_TYPE(s32, u32, 1), - ASSIGN_FETCH_TYPE(s64, u64, 1), - ASSIGN_FETCH_TYPE_ALIAS(x8, u8, u8, 0), - ASSIGN_FETCH_TYPE_ALIAS(x16, u16, u16, 0), - ASSIGN_FETCH_TYPE_ALIAS(x32, u32, u32, 0), - ASSIGN_FETCH_TYPE_ALIAS(x64, u64, u64, 0), - - ASSIGN_FETCH_TYPE_END -}; - /* Note that we don't verify it, since the code does not come from user space */ static int process_fetch_insn(struct fetch_insn *code, struct pt_regs *regs, void *dest, @@ -581,8 +557,7 @@ static int create_trace_uprobe(int argc, char **argv)
/* Parse fetch argument */ ret = traceprobe_parse_probe_arg(arg, &tu->tp.size, parg, - is_return, false, - uprobes_fetch_type_table); + is_return, false); if (ret) { pr_info("Parse error at argument[%d]. (%d)\n", i, ret); goto error;
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Cleanup string fetching routine so that returns the consumed bytes of dynamic area and store the string information as data_loc format instead of data_rloc. This simplifies the fetcharg loop.
Signed-off-by: Masami Hiramatsu mhiramat@kernel.org --- kernel/trace/trace_kprobe.c | 51 +++++++++++++++++++------------------- kernel/trace/trace_probe.h | 26 ++++--------------- kernel/trace/trace_probe_tmpl.h | 52 +++++++++++++++++--------------------- kernel/trace/trace_uprobe.c | 53 ++++++++++++++++++++------------------- 4 files changed, 82 insertions(+), 100 deletions(-)
diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c index 4caf019b5917..02d19eff49bb 100644 --- a/kernel/trace/trace_kprobe.c +++ b/kernel/trace/trace_kprobe.c @@ -807,8 +807,8 @@ static const struct file_operations kprobe_profile_ops = { /* Kprobe specific fetch functions */
/* Return the length of string -- including null terminal byte */ -static nokprobe_inline void -fetch_store_strlen(unsigned long addr, void *dest) +static nokprobe_inline int +fetch_store_strlen(unsigned long addr) { mm_segment_t old_fs; int ret, len = 0; @@ -826,25 +826,22 @@ fetch_store_strlen(unsigned long addr, void *dest) pagefault_enable(); set_fs(old_fs);
- if (ret < 0) /* Failed to check the length */ - *(u32 *)dest = 0; - else - *(u32 *)dest = len; + return (ret < 0) ? ret : len; }
/* * Fetch a null-terminated string. Caller MUST set *(u32 *)buf with max * length and relative data location. */ -static nokprobe_inline void -fetch_store_string(unsigned long addr, void *dest) +static nokprobe_inline int +fetch_store_string(unsigned long addr, void *dest, void *base) { - int maxlen = get_rloc_len(*(u32 *)dest); - u8 *dst = get_rloc_data(dest); + int maxlen = get_loc_len(*(u32 *)dest); + u8 *dst = get_loc_data(dest, base); long ret;
if (!maxlen) - return; + return -ENOMEM;
/* * Try to get string again, since the string can be changed while @@ -854,19 +851,19 @@ fetch_store_string(unsigned long addr, void *dest)
if (ret < 0) { /* Failed to fetch string */ dst[0] = '\0'; - *(u32 *)dest = make_data_rloc(0, get_rloc_offs(*(u32 *)dest)); - } else { - *(u32 *)dest = make_data_rloc(ret, get_rloc_offs(*(u32 *)dest)); + ret = 0; } + *(u32 *)dest = make_data_loc(ret, (void *)dst - base); + return ret; }
/* Note that we don't verify it, since the code does not come from user space */ static int process_fetch_insn(struct fetch_insn *code, struct pt_regs *regs, void *dest, - bool pre) + void *base) { unsigned long val; - int ret; + int ret = 0;
/* 1st stage: get value from context */ switch (code->op) { @@ -903,6 +900,13 @@ process_fetch_insn(struct fetch_insn *code, struct pt_regs *regs, void *dest, }
/* 3rd stage: store value to buffer */ + if (unlikely(!dest)) { + if (code->op == FETCH_OP_ST_STRING) + return fetch_store_strlen(val + code->offset); + else + return -EILSEQ; + } + switch (code->op) { case FETCH_OP_ST_RAW: fetch_store_raw(val, code, dest); @@ -911,10 +915,7 @@ process_fetch_insn(struct fetch_insn *code, struct pt_regs *regs, void *dest, probe_kernel_read(dest, (void *)val + code->offset, code->size); break; case FETCH_OP_ST_STRING: - if (pre) - fetch_store_strlen(val + code->offset, dest); - else - fetch_store_string(val + code->offset, dest); + ret = fetch_store_string(val + code->offset, dest, base); break; default: return -EILSEQ; @@ -927,7 +928,7 @@ process_fetch_insn(struct fetch_insn *code, struct pt_regs *regs, void *dest, code++; }
- return code->op == FETCH_OP_END ? 0 : -EILSEQ; + return code->op == FETCH_OP_END ? ret : -EILSEQ; } NOKPROBE_SYMBOL(process_fetch_insn)
@@ -962,7 +963,7 @@ __kprobe_trace_func(struct trace_kprobe *tk, struct pt_regs *regs,
entry = ring_buffer_event_data(event); entry->ip = (unsigned long)tk->rp.kp.addr; - store_trace_args(sizeof(*entry), &tk->tp, regs, (u8 *)&entry[1], dsize); + store_trace_args(&entry[1], &tk->tp, regs, sizeof(*entry), dsize);
event_trigger_unlock_commit_regs(trace_file, buffer, event, entry, irq_flags, pc, regs); @@ -1011,7 +1012,7 @@ __kretprobe_trace_func(struct trace_kprobe *tk, struct kretprobe_instance *ri, entry = ring_buffer_event_data(event); entry->func = (unsigned long)tk->rp.kp.addr; entry->ret_ip = (unsigned long)ri->ret_addr; - store_trace_args(sizeof(*entry), &tk->tp, regs, (u8 *)&entry[1], dsize); + store_trace_args(&entry[1], &tk->tp, regs, sizeof(*entry), dsize);
event_trigger_unlock_commit_regs(trace_file, buffer, event, entry, irq_flags, pc, regs); @@ -1162,7 +1163,7 @@ kprobe_perf_func(struct trace_kprobe *tk, struct pt_regs *regs)
entry->ip = (unsigned long)tk->rp.kp.addr; memset(&entry[1], 0, dsize); - store_trace_args(sizeof(*entry), &tk->tp, regs, (u8 *)&entry[1], dsize); + store_trace_args(&entry[1], &tk->tp, regs, sizeof(*entry), dsize); perf_trace_buf_submit(entry, size, rctx, call->event.type, 1, regs, head, NULL); return 0; @@ -1198,7 +1199,7 @@ kretprobe_perf_func(struct trace_kprobe *tk, struct kretprobe_instance *ri,
entry->func = (unsigned long)tk->rp.kp.addr; entry->ret_ip = (unsigned long)ri->ret_addr; - store_trace_args(sizeof(*entry), &tk->tp, regs, (u8 *)&entry[1], dsize); + store_trace_args(&entry[1], &tk->tp, regs, sizeof(*entry), dsize); perf_trace_buf_submit(entry, size, rctx, call->event.type, 1, regs, head, NULL); } diff --git a/kernel/trace/trace_probe.h b/kernel/trace/trace_probe.h index 89d853ef5174..d1b8bd74bf56 100644 --- a/kernel/trace/trace_probe.h +++ b/kernel/trace/trace_probe.h @@ -66,29 +66,15 @@ #define TP_FLAG_PROFILE 2 #define TP_FLAG_REGISTERED 4
+/* data_loc: data location, compatible with u32 */ +#define make_data_loc(len, offs) \ + (((u32)(len) << 16) | ((u32)(offs) & 0xffff)) +#define get_loc_len(dl) ((u32)(dl) >> 16) +#define get_loc_offs(dl) ((u32)(dl) & 0xffff)
-/* data_rloc: data relative location, compatible with u32 */ -#define make_data_rloc(len, roffs) \ - (((u32)(len) << 16) | ((u32)(roffs) & 0xffff)) -#define get_rloc_len(dl) ((u32)(dl) >> 16) -#define get_rloc_offs(dl) ((u32)(dl) & 0xffff) - -/* - * Convert data_rloc to data_loc: - * data_rloc stores the offset from data_rloc itself, but data_loc - * stores the offset from event entry. - */ -#define convert_rloc_to_loc(dl, offs) ((u32)(dl) + (offs)) - -static nokprobe_inline void *get_rloc_data(u32 *dl) -{ - return (u8 *)dl + get_rloc_offs(*dl); -} - -/* For data_loc conversion */ static nokprobe_inline void *get_loc_data(u32 *dl, void *ent) { - return (u8 *)ent + get_rloc_offs(*dl); + return (u8 *)ent + get_loc_offs(*dl); }
/* Printing function type */ diff --git a/kernel/trace/trace_probe_tmpl.h b/kernel/trace/trace_probe_tmpl.h index c8a5272abf01..d9aebd395a9d 100644 --- a/kernel/trace/trace_probe_tmpl.h +++ b/kernel/trace/trace_probe_tmpl.h @@ -48,24 +48,28 @@ fetch_apply_bitfield(struct fetch_insn *code, void *buf) } }
-/* Define this for each callsite */ +/* + * This must be defined for each callsite. + * Return consumed dynamic data size (>= 0), or error (< 0). + * If dest is NULL, don't store result and return required dynamic data size. + */ static int process_fetch_insn(struct fetch_insn *code, struct pt_regs *regs, - void *dest, bool pre); + void *dest, void *base);
/* Sum up total data length for dynamic arraies (strings) */ static nokprobe_inline int __get_data_size(struct trace_probe *tp, struct pt_regs *regs) { struct probe_arg *arg; - int i, ret = 0; - u32 len; + int i, len, ret = 0;
for (i = 0; i < tp->nr_args; i++) { arg = tp->args + i; if (unlikely(arg->dynamic)) { - process_fetch_insn(arg->code, regs, &len, true); - ret += len; + len = process_fetch_insn(arg->code, regs, NULL, NULL); + if (len > 0) + ret += len; } }
@@ -74,34 +78,24 @@ __get_data_size(struct trace_probe *tp, struct pt_regs *regs)
/* Store the value of each argument */ static nokprobe_inline void -store_trace_args(int ent_size, struct trace_probe *tp, struct pt_regs *regs, - u8 *data, int maxlen) +store_trace_args(void *data, struct trace_probe *tp, struct pt_regs *regs, + int header_size, int maxlen) { struct probe_arg *arg; - u32 end = tp->size; - u32 *dl; /* Data (relative) location */ - int i; + void *base = data - header_size; + void *dyndata = data + tp->size; + u32 *dl; /* Data location */ + int ret, i;
for (i = 0; i < tp->nr_args; i++) { arg = tp->args + i; - if (unlikely(arg->dynamic)) { - /* - * First, we set the relative location and - * maximum data length to *dl - */ - dl = (u32 *)(data + arg->offset); - *dl = make_data_rloc(maxlen, end - arg->offset); - /* Then try to fetch string or dynamic array data */ - process_fetch_insn(arg->code, regs, dl, false); - /* Reduce maximum length */ - end += get_rloc_len(*dl); - maxlen -= get_rloc_len(*dl); - /* Trick here, convert data_rloc to data_loc */ - *dl = convert_rloc_to_loc(*dl, ent_size + arg->offset); - } else - /* Just fetching data normally */ - process_fetch_insn(arg->code, regs, data + arg->offset, - false); + dl = data + arg->offset; + /* Point the dynamic data area if needed */ + if (unlikely(arg->dynamic)) + *dl = make_data_loc(maxlen, dyndata - base); + ret = process_fetch_insn(arg->code, regs, dl, base); + if (ret > 0) + dyndata += ret; } }
diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c index 9fc0123c721f..de4f91bb313a 100644 --- a/kernel/trace/trace_uprobe.c +++ b/kernel/trace/trace_uprobe.c @@ -121,41 +121,38 @@ probe_user_read(void *dest, void *src, size_t size) * Fetch a null-terminated string. Caller MUST set *(u32 *)dest with max * length and relative data location. */ -static nokprobe_inline void -fetch_store_string(unsigned long addr, void *dest) +static nokprobe_inline int +fetch_store_string(unsigned long addr, void *dest, void *base) { long ret; - u32 rloc = *(u32 *)dest; - int maxlen = get_rloc_len(rloc); - u8 *dst = get_rloc_data(dest); + u32 loc = *(u32 *)dest; + int maxlen = get_loc_len(loc); + u8 *dst = get_loc_data(dest, base); void __user *src = (void __force __user *) addr;
if (!maxlen) - return; + return -ENOMEM;
ret = strncpy_from_user(dst, src, maxlen);
if (ret < 0) { /* Failed to fetch string */ - ((u8 *)get_rloc_data(dest))[0] = '\0'; - *(u32 *)dest = make_data_rloc(0, get_rloc_offs(rloc)); - } else { - *(u32 *)dest = make_data_rloc(ret, get_rloc_offs(rloc)); + dst[0] = '\0'; + ret = 0; } + *(u32 *)dest = make_data_loc(ret, (void *)dst - base); + return ret; }
/* Return the length of string -- including null terminal byte */ -static nokprobe_inline void -fetch_store_strlen(unsigned long addr, void *dest) +static nokprobe_inline int +fetch_store_strlen(unsigned long addr) { int len; void __user *vaddr = (void __force __user *) addr;
len = strnlen_user(vaddr, MAX_STRING_SIZE);
- if (len == 0 || len > MAX_STRING_SIZE) /* Failed to check length */ - *(u32 *)dest = 0; - else - *(u32 *)dest = len; + return (len > MAX_STRING_SIZE) ? 0 : len; }
static unsigned long translate_user_vaddr(unsigned long file_offset) @@ -172,10 +169,10 @@ static unsigned long translate_user_vaddr(unsigned long file_offset) /* Note that we don't verify it, since the code does not come from user space */ static int process_fetch_insn(struct fetch_insn *code, struct pt_regs *regs, void *dest, - bool pre) + void *base) { unsigned long val; - int ret; + int ret = 0;
/* 1st stage: get value from context */ switch (code->op) { @@ -212,18 +209,22 @@ process_fetch_insn(struct fetch_insn *code, struct pt_regs *regs, void *dest, }
/* 3rd stage: store value to buffer */ + if (unlikely(!dest)) { + if (code->op == FETCH_OP_ST_STRING) + return fetch_store_strlen(val + code->offset); + else + return -EILSEQ; + } + switch (code->op) { case FETCH_OP_ST_RAW: fetch_store_raw(val, code, dest); break; case FETCH_OP_ST_MEM: - probe_user_read(dest, (void *)val + code->offset, code->size); + probe_kernel_read(dest, (void *)val + code->offset, code->size); break; case FETCH_OP_ST_STRING: - if (pre) - fetch_store_strlen(val + code->offset, dest); - else - fetch_store_string(val + code->offset, dest); + ret = fetch_store_string(val + code->offset, dest, base); break; default: return -EILSEQ; @@ -236,7 +237,7 @@ process_fetch_insn(struct fetch_insn *code, struct pt_regs *regs, void *dest, code++; }
- return code->op == FETCH_OP_END ? 0 : -EILSEQ; + return code->op == FETCH_OP_END ? ret : -EILSEQ; } NOKPROBE_SYMBOL(process_fetch_insn)
@@ -1242,7 +1243,7 @@ static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs) esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
ucb = uprobe_buffer_get(); - store_trace_args(esize, &tu->tp, regs, ucb->buf, dsize); + store_trace_args(ucb->buf, &tu->tp, regs, esize, dsize);
if (tu->tp.flags & TP_FLAG_TRACE) ret |= uprobe_trace_func(tu, regs, ucb, dsize); @@ -1277,7 +1278,7 @@ static int uretprobe_dispatcher(struct uprobe_consumer *con, esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
ucb = uprobe_buffer_get(); - store_trace_args(esize, &tu->tp, regs, ucb->buf, dsize); + store_trace_args(ucb->buf, &tu->tp, regs, esize, dsize);
if (tu->tp.flags & TP_FLAG_TRACE) uretprobe_trace_func(tu, func, regs, ucb, dsize);
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Append traceprobe_ for exported function set_print_fmt() as same as other functions.
Signed-off-by: Masami Hiramatsu mhiramat@kernel.org --- kernel/trace/trace_kprobe.c | 4 ++-- kernel/trace/trace_probe.c | 2 +- kernel/trace/trace_probe.h | 2 +- kernel/trace/trace_uprobe.c | 4 ++-- 4 files changed, 6 insertions(+), 6 deletions(-)
diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c index 02d19eff49bb..35f81e1eb70e 100644 --- a/kernel/trace/trace_kprobe.c +++ b/kernel/trace/trace_kprobe.c @@ -1305,7 +1305,7 @@ static int register_kprobe_event(struct trace_kprobe *tk)
init_trace_event_call(tk, call);
- if (set_print_fmt(&tk->tp, trace_kprobe_is_return(tk)) < 0) + if (traceprobe_set_print_fmt(&tk->tp, trace_kprobe_is_return(tk)) < 0) return -ENOMEM; ret = register_trace_event(&call->event); if (!ret) { @@ -1362,7 +1362,7 @@ create_local_trace_kprobe(char *func, void *addr, unsigned long offs,
init_trace_event_call(tk, &tk->tp.call);
- if (set_print_fmt(&tk->tp, trace_kprobe_is_return(tk)) < 0) { + if (traceprobe_set_print_fmt(&tk->tp, trace_kprobe_is_return(tk)) < 0) { ret = -ENOMEM; goto error; } diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c index 9ffc07c7c949..9c1b55e0ccfd 100644 --- a/kernel/trace/trace_probe.c +++ b/kernel/trace/trace_probe.c @@ -502,7 +502,7 @@ static int __set_print_fmt(struct trace_probe *tp, char *buf, int len, return pos; }
-int set_print_fmt(struct trace_probe *tp, bool is_return) +int traceprobe_set_print_fmt(struct trace_probe *tp, bool is_return) { int len; char *print_fmt; diff --git a/kernel/trace/trace_probe.h b/kernel/trace/trace_probe.h index d1b8bd74bf56..3bc43c1ce628 100644 --- a/kernel/trace/trace_probe.h +++ b/kernel/trace/trace_probe.h @@ -266,7 +266,7 @@ extern void traceprobe_free_probe_arg(struct probe_arg *arg);
extern int traceprobe_split_symbol_offset(char *symbol, long *offset);
-extern int set_print_fmt(struct trace_probe *tp, bool is_return); +extern int traceprobe_set_print_fmt(struct trace_probe *tp, bool is_return);
#ifdef CONFIG_PERF_EVENTS extern struct trace_event_call * diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c index de4f91bb313a..fafd48310823 100644 --- a/kernel/trace/trace_uprobe.c +++ b/kernel/trace/trace_uprobe.c @@ -1314,7 +1314,7 @@ static int register_uprobe_event(struct trace_uprobe *tu)
init_trace_event_call(tu, call);
- if (set_print_fmt(&tu->tp, is_ret_probe(tu)) < 0) + if (traceprobe_set_print_fmt(&tu->tp, is_ret_probe(tu)) < 0) return -ENOMEM;
ret = register_trace_event(&call->event); @@ -1388,7 +1388,7 @@ create_local_trace_uprobe(char *name, unsigned long offs, bool is_return) tu->filename = kstrdup(name, GFP_KERNEL); init_trace_event_call(tu, &tu->tp.call);
- if (set_print_fmt(&tu->tp, is_ret_probe(tu)) < 0) { + if (traceprobe_set_print_fmt(&tu->tp, is_ret_probe(tu)) < 0) { ret = -ENOMEM; goto error; }
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Unify the fetch_insn bottom process (from stage 2: dereference indirect data) from kprobe and uprobe events, since those are mostly same.
Signed-off-by: Masami Hiramatsu mhiramat@kernel.org --- kernel/trace/trace_kprobe.c | 47 +++++---------------------------- kernel/trace/trace_probe_tmpl.h | 55 ++++++++++++++++++++++++++++++++++++++- kernel/trace/trace_uprobe.c | 43 +----------------------------- 3 files changed, 63 insertions(+), 82 deletions(-)
diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c index 35f81e1eb70e..292d5ae6d18b 100644 --- a/kernel/trace/trace_kprobe.c +++ b/kernel/trace/trace_kprobe.c @@ -857,13 +857,18 @@ fetch_store_string(unsigned long addr, void *dest, void *base) return ret; }
+static nokprobe_inline int +probe_mem_read(void *dest, void *src, size_t size) +{ + return probe_kernel_read(dest, src, size); +} + /* Note that we don't verify it, since the code does not come from user space */ static int process_fetch_insn(struct fetch_insn *code, struct pt_regs *regs, void *dest, void *base) { unsigned long val; - int ret = 0;
/* 1st stage: get value from context */ switch (code->op) { @@ -890,45 +895,7 @@ process_fetch_insn(struct fetch_insn *code, struct pt_regs *regs, void *dest, } code++;
- /* 2nd stage: dereference memory if needed */ - while (code->op == FETCH_OP_DEREF) { - ret = probe_kernel_read(&val, (void *)val + code->offset, - sizeof(val)); - if (ret) - return ret; - code++; - } - - /* 3rd stage: store value to buffer */ - if (unlikely(!dest)) { - if (code->op == FETCH_OP_ST_STRING) - return fetch_store_strlen(val + code->offset); - else - return -EILSEQ; - } - - switch (code->op) { - case FETCH_OP_ST_RAW: - fetch_store_raw(val, code, dest); - break; - case FETCH_OP_ST_MEM: - probe_kernel_read(dest, (void *)val + code->offset, code->size); - break; - case FETCH_OP_ST_STRING: - ret = fetch_store_string(val + code->offset, dest, base); - break; - default: - return -EILSEQ; - } - code++; - - /* 4th stage: modify stored value if needed */ - if (code->op == FETCH_OP_MOD_BF) { - fetch_apply_bitfield(code, dest); - code++; - } - - return code->op == FETCH_OP_END ? ret : -EILSEQ; + return process_fetch_insn_bottom(code, val, dest, base); } NOKPROBE_SYMBOL(process_fetch_insn)
diff --git a/kernel/trace/trace_probe_tmpl.h b/kernel/trace/trace_probe_tmpl.h index d9aebd395a9d..32ae2fc78190 100644 --- a/kernel/trace/trace_probe_tmpl.h +++ b/kernel/trace/trace_probe_tmpl.h @@ -49,13 +49,66 @@ fetch_apply_bitfield(struct fetch_insn *code, void *buf) }
/* - * This must be defined for each callsite. + * These functions must be defined for each callsite. * Return consumed dynamic data size (>= 0), or error (< 0). * If dest is NULL, don't store result and return required dynamic data size. */ static int process_fetch_insn(struct fetch_insn *code, struct pt_regs *regs, void *dest, void *base); +static nokprobe_inline int fetch_store_strlen(unsigned long addr); +static nokprobe_inline int +fetch_store_string(unsigned long addr, void *dest, void *base); +static nokprobe_inline int +probe_mem_read(void *dest, void *src, size_t size); + +/* From the 2nd stage, routine is same */ +static nokprobe_inline int +process_fetch_insn_bottom(struct fetch_insn *code, unsigned long val, + void *dest, void *base) +{ + int ret = 0; + + /* 2nd stage: dereference memory if needed */ + while (code->op == FETCH_OP_DEREF) { + ret = probe_mem_read(&val, (void *)val + code->offset, + sizeof(val)); + if (ret) + return ret; + code++; + } + + /* 3rd stage: store value to buffer */ + if (unlikely(!dest)) { + if (code->op == FETCH_OP_ST_STRING) + return fetch_store_strlen(val + code->offset); + else + return -EILSEQ; + } + + switch (code->op) { + case FETCH_OP_ST_RAW: + fetch_store_raw(val, code, dest); + break; + case FETCH_OP_ST_MEM: + probe_mem_read(dest, (void *)val + code->offset, code->size); + break; + case FETCH_OP_ST_STRING: + ret = fetch_store_string(val + code->offset, dest, base); + break; + default: + return -EILSEQ; + } + code++; + + /* 4th stage: modify stored value if needed */ + if (code->op == FETCH_OP_MOD_BF) { + fetch_apply_bitfield(code, dest); + code++; + } + + return code->op == FETCH_OP_END ? ret : -EILSEQ; +}
/* Sum up total data length for dynamic arraies (strings) */ static nokprobe_inline int diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c index fafd48310823..64c1fbe087a1 100644 --- a/kernel/trace/trace_uprobe.c +++ b/kernel/trace/trace_uprobe.c @@ -111,7 +111,7 @@ static unsigned long get_user_stack_nth(struct pt_regs *regs, unsigned int n) * Uprobes-specific fetch functions */ static nokprobe_inline int -probe_user_read(void *dest, void *src, size_t size) +probe_mem_read(void *dest, void *src, size_t size) { void __user *vaddr = (void __force __user *)src;
@@ -172,7 +172,6 @@ process_fetch_insn(struct fetch_insn *code, struct pt_regs *regs, void *dest, void *base) { unsigned long val; - int ret = 0;
/* 1st stage: get value from context */ switch (code->op) { @@ -199,45 +198,7 @@ process_fetch_insn(struct fetch_insn *code, struct pt_regs *regs, void *dest, } code++;
- /* 2nd stage: dereference memory if needed */ - while (code->op == FETCH_OP_DEREF) { - ret = probe_user_read(&val, (void *)val + code->offset, - sizeof(val)); - if (ret) - return ret; - code++; - } - - /* 3rd stage: store value to buffer */ - if (unlikely(!dest)) { - if (code->op == FETCH_OP_ST_STRING) - return fetch_store_strlen(val + code->offset); - else - return -EILSEQ; - } - - switch (code->op) { - case FETCH_OP_ST_RAW: - fetch_store_raw(val, code, dest); - break; - case FETCH_OP_ST_MEM: - probe_kernel_read(dest, (void *)val + code->offset, code->size); - break; - case FETCH_OP_ST_STRING: - ret = fetch_store_string(val + code->offset, dest, base); - break; - default: - return -EILSEQ; - } - code++; - - /* 4th stage: modify stored value if needed */ - if (code->op == FETCH_OP_MOD_BF) { - fetch_apply_bitfield(code, dest); - code++; - } - - return code->op == FETCH_OP_END ? ret : -EILSEQ; + return process_fetch_insn_bottom(code, val, dest, base); } NOKPROBE_SYMBOL(process_fetch_insn)
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Add "symbol" type to probeevent, which is an alias of u32 or u64 (depends on BITS_PER_LONG). This shows the result value in symbol+offset style. This type is only available with kprobe events.
Signed-off-by: Masami Hiramatsu mhiramat@kernel.org --- Changes in v2: - Add symbol type to README file. --- Documentation/trace/kprobetrace.txt | 3 +++ kernel/trace/trace.c | 2 +- kernel/trace/trace_probe.c | 8 ++++++++ kernel/trace/trace_probe.h | 12 +++++++++--- 4 files changed, 21 insertions(+), 4 deletions(-)
diff --git a/Documentation/trace/kprobetrace.txt b/Documentation/trace/kprobetrace.txt index 1a3a3d6bc2a8..d49381f2e411 100644 --- a/Documentation/trace/kprobetrace.txt +++ b/Documentation/trace/kprobetrace.txt @@ -62,6 +62,7 @@ respectively. 'x' prefix implies it is unsigned. Traced arguments are shown in decimal ('s' and 'u') or hexadecimal ('x'). Without type casting, 'x32' or 'x64' is used depends on the architecture (e.g. x86-32 uses x32, and x86-64 uses x64). + String type is a special type, which fetches a "null-terminated" string from kernel space. This means it will fail and store NULL if the string container has been paged out. @@ -70,6 +71,8 @@ offset, and container-size (usually 32). The syntax is;
b<bit-width>@<bit-offset>/<container-size>
+Symbol type('symbol') is an alias of u32 or u64 type (depends on BITS_PER_LONG) +which shows given pointer in "symbol+offset" style. For $comm, the default type is "string"; any other type is invalid.
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 20a2300ae4e8..8f08811d15b8 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -4609,7 +4609,7 @@ static const char readme_msg[] = "\t args: <name>=fetcharg[:type]\n" "\t fetcharg: %<register>, @<address>, @<symbol>[+|-<offset>],\n" "\t $stack<index>, $stack, $retval, $comm\n" - "\t type: s8/16/32/64, u8/16/32/64, x8/16/32/64, string,\n" + "\t type: s8/16/32/64, u8/16/32/64, x8/16/32/64, string, symbol,\n" "\t b<bit-width>@<bit-offset>/<container-size>\n" #endif " events/\t\t- Directory containing all trace event subsystems:\n" diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c index 9c1b55e0ccfd..4c83b00ebec0 100644 --- a/kernel/trace/trace_probe.c +++ b/kernel/trace/trace_probe.c @@ -58,6 +58,13 @@ DEFINE_BASIC_PRINT_TYPE_FUNC(x16, u16, "0x%x") DEFINE_BASIC_PRINT_TYPE_FUNC(x32, u32, "0x%x") DEFINE_BASIC_PRINT_TYPE_FUNC(x64, u64, "0x%Lx")
+int PRINT_TYPE_FUNC_NAME(symbol)(struct trace_seq *s, void *data, void *ent) +{ + trace_seq_printf(s, "%pS", (void *)*(unsigned long *)data); + return !trace_seq_has_overflowed(s); +} +const char PRINT_TYPE_FMT_NAME(symbol)[] = "%pS"; + /* Print type function for string type */ int PRINT_TYPE_FUNC_NAME(string)(struct trace_seq *s, void *data, void *ent) { @@ -91,6 +98,7 @@ static const struct fetch_type probe_fetch_types[] = { ASSIGN_FETCH_TYPE_ALIAS(x16, u16, u16, 0), ASSIGN_FETCH_TYPE_ALIAS(x32, u32, u32, 0), ASSIGN_FETCH_TYPE_ALIAS(x64, u64, u64, 0), + ASSIGN_FETCH_TYPE_ALIAS(symbol, ADDR_FETCH_TYPE, ADDR_FETCH_TYPE, 0),
ASSIGN_FETCH_TYPE_END }; diff --git a/kernel/trace/trace_probe.h b/kernel/trace/trace_probe.h index 3bc43c1ce628..ef477bd8468a 100644 --- a/kernel/trace/trace_probe.h +++ b/kernel/trace/trace_probe.h @@ -157,6 +157,7 @@ DECLARE_BASIC_PRINT_TYPE_FUNC(x32); DECLARE_BASIC_PRINT_TYPE_FUNC(x64);
DECLARE_BASIC_PRINT_TYPE_FUNC(string); +DECLARE_BASIC_PRINT_TYPE_FUNC(symbol);
/* Default (unsigned long) fetch type */ #define __DEFAULT_FETCH_TYPE(t) x##t @@ -164,6 +165,10 @@ DECLARE_BASIC_PRINT_TYPE_FUNC(string); #define DEFAULT_FETCH_TYPE _DEFAULT_FETCH_TYPE(BITS_PER_LONG) #define DEFAULT_FETCH_TYPE_STR __stringify(DEFAULT_FETCH_TYPE)
+#define __ADDR_FETCH_TYPE(t) u##t +#define _ADDR_FETCH_TYPE(t) __ADDR_FETCH_TYPE(t) +#define ADDR_FETCH_TYPE _ADDR_FETCH_TYPE(BITS_PER_LONG) + #define __ASSIGN_FETCH_TYPE(_name, ptype, ftype, _size, sign, _fmttype) \ {.name = _name, \ .size = _size, \ @@ -172,13 +177,14 @@ DECLARE_BASIC_PRINT_TYPE_FUNC(string); .fmt = PRINT_TYPE_FMT_NAME(ptype), \ .fmttype = _fmttype, \ } - +#define _ASSIGN_FETCH_TYPE(_name, ptype, ftype, _size, sign, _fmttype) \ + __ASSIGN_FETCH_TYPE(_name, ptype, ftype, _size, sign, #_fmttype) #define ASSIGN_FETCH_TYPE(ptype, ftype, sign) \ - __ASSIGN_FETCH_TYPE(#ptype, ptype, ftype, sizeof(ftype), sign, #ptype) + _ASSIGN_FETCH_TYPE(#ptype, ptype, ftype, sizeof(ftype), sign, ptype)
/* If ptype is an alias of atype, use this macro (show atype in format) */ #define ASSIGN_FETCH_TYPE_ALIAS(ptype, atype, ftype, sign) \ - __ASSIGN_FETCH_TYPE(#ptype, ptype, ftype, sizeof(ftype), sign, #atype) + _ASSIGN_FETCH_TYPE(#ptype, ptype, ftype, sizeof(ftype), sign, atype)
#define ASSIGN_FETCH_TYPE_END {}
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Add regs_get_argument() which returns N th argument of the function call. Note that this chooses most probably assignment, in some case it can be incorrect (e.g. passing data structure or floating point etc.)
This is expected to be called from kprobes or ftrace with regs where the top of stack is the return address.
Signed-off-by: Masami Hiramatsu mhiramat@kernel.org --- arch/Kconfig | 7 +++++++ arch/x86/Kconfig | 1 + arch/x86/include/asm/ptrace.h | 38 ++++++++++++++++++++++++++++++++++++++ 3 files changed, 46 insertions(+)
diff --git a/arch/Kconfig b/arch/Kconfig index 76c0b54443b1..4126ad4b122c 100644 --- a/arch/Kconfig +++ b/arch/Kconfig @@ -272,6 +272,13 @@ config HAVE_REGS_AND_STACK_ACCESS_API declared in asm/ptrace.h For example the kprobes-based event tracer needs this API.
+config HAVE_FUNCTION_ARG_ACCESS_API + bool + help + This symbol should be selected by an architecure if it supports + the API needed to access function arguments from pt_regs, + declared in asm/ptrace.h + config HAVE_CLK bool help diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 552b3d0eae36..eb0cad381ace 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -176,6 +176,7 @@ config X86 select HAVE_PERF_USER_STACK_DUMP select HAVE_RCU_TABLE_FREE select HAVE_REGS_AND_STACK_ACCESS_API + select HAVE_FUNCTION_ARG_ACCESS_API select HAVE_RELIABLE_STACKTRACE if X86_64 && UNWINDER_FRAME_POINTER && STACK_VALIDATION select HAVE_STACK_VALIDATION if X86_64 select HAVE_SYSCALL_TRACEPOINTS diff --git a/arch/x86/include/asm/ptrace.h b/arch/x86/include/asm/ptrace.h index 6de1fd3d0097..c2304b25e2fd 100644 --- a/arch/x86/include/asm/ptrace.h +++ b/arch/x86/include/asm/ptrace.h @@ -256,6 +256,44 @@ static inline unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, return 0; }
+/** + * regs_get_kernel_argument() - get Nth function argument in kernel + * @regs: pt_regs of that context + * @n: function argument number (start from 0) + * + * regs_get_argument() returns @n th argument of the function call. + * Note that this chooses most probably assignment, in some case + * it can be incorrect. + * This is expected to be called from kprobes or ftrace with regs + * where the top of stack is the return address. + */ +static inline unsigned long regs_get_kernel_argument(struct pt_regs *regs, + unsigned int n) +{ + static const unsigned int argument_offs[] = { +#ifdef __i386__ + offsetof(struct pt_regs, ax), + offsetof(struct pt_regs, cx), + offsetof(struct pt_regs, dx), +#define NR_REG_ARGUMENTS 3 +#else + offsetof(struct pt_regs, di), + offsetof(struct pt_regs, si), + offsetof(struct pt_regs, dx), + offsetof(struct pt_regs, cx), + offsetof(struct pt_regs, r8), + offsetof(struct pt_regs, r9), +#define NR_REG_ARGUMENTS 6 +#endif + }; + + if (n >= NR_REG_ARGUMENTS) { + n -= NR_REG_ARGUMENTS - 1; + return regs_get_kernel_stack_nth(regs, n); + } else + return regs_get_register(regs, argument_offs[n]); +} + #define arch_has_single_step() (1) #ifdef CONFIG_X86_DEBUGCTLMSR #define arch_has_block_step() (1)
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Add $argN special fetch variable for accessing function arguments. This allows user to trace the Nth argument easily at the function entry.
Note that this returns most probably assignment of registers and stacks. In some case, it may not work well. If you need to access correct registers or stacks you should use perf-probe.
Signed-off-by: Masami Hiramatsu mhiramat@kernel.org --- Changes in v2: - Add $argN in README file - Make N start from 1 as same as auto-generate event argument names. Changes in v3: - Show $arg<N> in README only when this feature is supported. --- Documentation/trace/kprobetrace.txt | 10 ++++++---- kernel/trace/trace.c | 4 ++++ kernel/trace/trace_kprobe.c | 18 +++++++++++++----- kernel/trace/trace_probe.c | 36 ++++++++++++++++++++++------------- kernel/trace/trace_probe.h | 9 ++++++++- kernel/trace/trace_uprobe.c | 2 +- 6 files changed, 55 insertions(+), 24 deletions(-)
diff --git a/Documentation/trace/kprobetrace.txt b/Documentation/trace/kprobetrace.txt index d49381f2e411..1d082f8ffeee 100644 --- a/Documentation/trace/kprobetrace.txt +++ b/Documentation/trace/kprobetrace.txt @@ -43,16 +43,18 @@ Synopsis of kprobe_events @SYM[+|-offs] : Fetch memory at SYM +|- offs (SYM should be a data symbol) $stackN : Fetch Nth entry of stack (N >= 0) $stack : Fetch stack address. - $retval : Fetch return value.(*) + $argN : Fetch the Nth function argument. (N >= 1) (*1) + $retval : Fetch return value.(*2) $comm : Fetch current task comm. - +|-offs(FETCHARG) : Fetch memory at FETCHARG +|- offs address.(**) + +|-offs(FETCHARG) : Fetch memory at FETCHARG +|- offs address.(*3) NAME=FETCHARG : Set NAME as the argument name of FETCHARG. FETCHARG:TYPE : Set TYPE as the type of FETCHARG. Currently, basic types (u8/u16/u32/u64/s8/s16/s32/s64), hexadecimal types (x8/x16/x32/x64), "string" and bitfield are supported.
- (*) only for return probe. - (**) this is useful for fetching a field of data structures. + (*1) only for the probe on function entry (offs == 0). + (*2) only for return probe. + (*3) this is useful for fetching a field of data structures.
Types ----- diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 8f08811d15b8..bcd1fd87082d 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -4608,7 +4608,11 @@ static const char readme_msg[] = #endif "\t args: <name>=fetcharg[:type]\n" "\t fetcharg: %<register>, @<address>, @<symbol>[+|-<offset>],\n" +#ifdef CONFIG_HAVE_FUNCTION_ARG_ACCESS_API + "\t $stack<index>, $stack, $retval, $comm, $arg<N>\n" +#else "\t $stack<index>, $stack, $retval, $comm\n" +#endif "\t type: s8/16/32/64, u8/16/32/64, x8/16/32/64, string, symbol,\n" "\t b<bit-width>@<bit-offset>/<container-size>\n" #endif diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c index 292d5ae6d18b..e5a52b5f70ec 100644 --- a/kernel/trace/trace_kprobe.c +++ b/kernel/trace/trace_kprobe.c @@ -490,13 +490,15 @@ static int create_trace_kprobe(int argc, char **argv) long offset = 0; void *addr = NULL; char buf[MAX_EVENT_NAME_LEN]; + unsigned int flags = TPARG_FL_KERNEL;
/* argc must be >= 1 */ if (argv[0][0] == 'p') is_return = false; - else if (argv[0][0] == 'r') + else if (argv[0][0] == 'r') { is_return = true; - else if (argv[0][0] == '-') + flags |= TPARG_FL_RETURN; + } else if (argv[0][0] == '-') is_delete = true; else { pr_info("Probe definition must be started with 'p', 'r' or" @@ -579,8 +581,9 @@ static int create_trace_kprobe(int argc, char **argv) pr_info("Failed to parse either an address or a symbol.\n"); return ret; } - if (offset && is_return && - !kprobe_on_func_entry(NULL, symbol, offset)) { + if (kprobe_on_func_entry(NULL, symbol, offset)) + flags |= TPARG_FL_FENTRY; + if (offset && is_return && !(flags & TPARG_FL_FENTRY)) { pr_info("Given offset is not valid for return probe.\n"); return -EINVAL; } @@ -650,7 +653,7 @@ static int create_trace_kprobe(int argc, char **argv)
/* Parse fetch argument */ ret = traceprobe_parse_probe_arg(arg, &tk->tp.size, parg, - is_return, true); + flags); if (ret) { pr_info("Parse error at argument[%d]. (%d)\n", i, ret); goto error; @@ -890,6 +893,11 @@ process_fetch_insn(struct fetch_insn *code, struct pt_regs *regs, void *dest, case FETCH_OP_COMM: val = (unsigned long)current->comm; break; +#ifdef CONFIG_HAVE_FUNCTION_ARG_ACCESS_API + case FETCH_OP_ARG: + val = regs_get_kernel_argument(regs, code->param); + break; +#endif default: return -EILSEQ; } diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c index 4c83b00ebec0..84887754702a 100644 --- a/kernel/trace/trace_probe.c +++ b/kernel/trace/trace_probe.c @@ -169,14 +169,13 @@ int traceprobe_split_symbol_offset(char *symbol, long *offset) #define PARAM_MAX_STACK (THREAD_SIZE / sizeof(unsigned long))
static int parse_probe_vars(char *arg, const struct fetch_type *t, - struct fetch_insn *code, bool is_return, - bool is_kprobe) + struct fetch_insn *code, unsigned int flags) { int ret = 0; unsigned long param;
if (strcmp(arg, "retval") == 0) { - if (is_return) + if (flags & TPARG_FL_RETURN) code->op = FETCH_OP_RETVAL; else ret = -EINVAL; @@ -185,7 +184,8 @@ static int parse_probe_vars(char *arg, const struct fetch_type *t, code->op = FETCH_OP_STACKP; } else if (isdigit(arg[5])) { ret = kstrtoul(arg + 5, 10, ¶m); - if (ret || (is_kprobe && param > PARAM_MAX_STACK)) + if (ret || ((flags & TPARG_FL_KERNEL) && + param > PARAM_MAX_STACK)) ret = -EINVAL; else { code->op = FETCH_OP_STACK; @@ -195,6 +195,18 @@ static int parse_probe_vars(char *arg, const struct fetch_type *t, ret = -EINVAL; } else if (strcmp(arg, "comm") == 0) { code->op = FETCH_OP_COMM; +#ifdef CONFIG_HAVE_FUNCTION_ARG_ACCESS_API + } else if (((flags & TPARG_FL_MASK) == + (TPARG_FL_KERNEL | TPARG_FL_FENTRY)) && + strncmp(arg, "arg", 3) == 0) { + if (!isdigit(arg[3])) + return -EINVAL; + ret = kstrtoul(arg + 3, 10, ¶m); + if (ret || !param || param > PARAM_MAX_STACK) + return -EINVAL; + code->op = FETCH_OP_ARG; + code->param = (unsigned int)param - 1; +#endif } else ret = -EINVAL;
@@ -205,7 +217,7 @@ static int parse_probe_vars(char *arg, const struct fetch_type *t, static int parse_probe_arg(char *arg, const struct fetch_type *type, struct fetch_insn **pcode, struct fetch_insn *end, - bool is_return, bool is_kprobe) + unsigned int flags) { struct fetch_insn *code = *pcode; unsigned long param; @@ -215,8 +227,7 @@ parse_probe_arg(char *arg, const struct fetch_type *type,
switch (arg[0]) { case '$': - ret = parse_probe_vars(arg + 1, type, code, - is_return, is_kprobe); + ret = parse_probe_vars(arg + 1, type, code, flags); break;
case '%': /* named register */ @@ -238,7 +249,7 @@ parse_probe_arg(char *arg, const struct fetch_type *type, code->immediate = param; } else if (arg[1] == '+') { /* kprobes don't support file offsets */ - if (is_kprobe) + if (flags & TPARG_FL_KERNEL) return -EINVAL;
ret = kstrtol(arg + 2, 0, &offset); @@ -249,7 +260,7 @@ parse_probe_arg(char *arg, const struct fetch_type *type, code->immediate = (unsigned long)offset; // imm64? } else { /* uprobes don't support symbols */ - if (!is_kprobe) + if (!(flags & TPARG_FL_KERNEL)) return -EINVAL;
ret = traceprobe_split_symbol_offset(arg + 1, &offset); @@ -290,8 +301,7 @@ parse_probe_arg(char *arg, const struct fetch_type *type, const struct fetch_type *t2 = find_fetch_type(NULL);
*tmp = '\0'; - ret = parse_probe_arg(arg, t2, &code, end, is_return, - is_kprobe); + ret = parse_probe_arg(arg, t2, &code, end, flags); if (ret) break; if (code->op == FETCH_OP_COMM) @@ -351,7 +361,7 @@ static int __parse_bitfield_probe_arg(const char *bf,
/* String length checking wrapper */ int traceprobe_parse_probe_arg(char *arg, ssize_t *size, - struct probe_arg *parg, bool is_return, bool is_kprobe) + struct probe_arg *parg, unsigned int flags) { struct fetch_insn *code, *tmp = NULL; const char *t; @@ -391,7 +401,7 @@ int traceprobe_parse_probe_arg(char *arg, ssize_t *size, code[FETCH_INSN_MAX - 1].op = FETCH_OP_END;
ret = parse_probe_arg(arg, parg->type, &code, &code[FETCH_INSN_MAX - 1], - is_return, is_kprobe); + flags); if (ret) goto fail;
diff --git a/kernel/trace/trace_probe.h b/kernel/trace/trace_probe.h index ef477bd8468a..ff91faf70887 100644 --- a/kernel/trace/trace_probe.h +++ b/kernel/trace/trace_probe.h @@ -35,6 +35,7 @@ #include <linux/stringify.h> #include <linux/limits.h> #include <linux/uaccess.h> +#include <linux/bitops.h> #include <asm/bitsperlong.h>
#include "trace.h" @@ -89,6 +90,7 @@ enum fetch_op { FETCH_OP_RETVAL, /* Return value */ FETCH_OP_IMM, /* Immediate : .immediate */ FETCH_OP_COMM, /* Current comm */ + FETCH_OP_ARG, /* Function argument : .param */ FETCH_OP_FOFFS, /* File offset: .immediate */ // Stage 2 (dereference) op FETCH_OP_DEREF, /* Dereference: .offset */ @@ -261,8 +263,13 @@ find_event_file_link(struct trace_probe *tp, struct trace_event_file *file) return NULL; }
+#define TPARG_FL_RETURN BIT(0) +#define TPARG_FL_KERNEL BIT(1) +#define TPARG_FL_FENTRY BIT(2) +#define TPARG_FL_MASK GENMASK(2, 0) + extern int traceprobe_parse_probe_arg(char *arg, ssize_t *size, - struct probe_arg *parg, bool is_return, bool is_kprobe); + struct probe_arg *parg, unsigned int flags);
extern int traceprobe_conflict_field_name(const char *name, struct probe_arg *args, int narg); diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c index 64c1fbe087a1..e15da2281855 100644 --- a/kernel/trace/trace_uprobe.c +++ b/kernel/trace/trace_uprobe.c @@ -519,7 +519,7 @@ static int create_trace_uprobe(int argc, char **argv)
/* Parse fetch argument */ ret = traceprobe_parse_probe_arg(arg, &tu->tp.size, parg, - is_return, false); + is_return ? TPARG_FL_RETURN : 0); if (ret) { pr_info("Parse error at argument[%d]. (%d)\n", i, ret); goto error;
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Add array type support for probe events. This allows user to get arraied types from memory address. The array type syntax is
TYPE[N]
Where TYPE is one of types (u8/16/32/64,s8/16/32/64, x8/16/32/64, symbol, string) and N is a fixed value less than 64.
The string array type is a bit different from other types. For other base types, <base-type>[1] is equal to <base-type> (e.g. +0(%di):x32[1] is same as +0(%di):x32.) But string[1] is not equal to string. The string type itself represents "char array", but string array type represents "char * array". So, for example, +0(%di):string[1] is equal to +0(+0(%di)):string.
Signed-off-by: Masami Hiramatsu mhiramat@kernel.org --- Changes in v2: - Add array description in README file - Fix to init s3 code out of loop. - Fix to proceed code when the last code is OP_ARRAY. - Add string array type and bitfield array type. --- Documentation/trace/kprobetrace.txt | 13 ++++ kernel/trace/trace.c | 3 + kernel/trace/trace_probe.c | 129 +++++++++++++++++++++++++++-------- kernel/trace/trace_probe.h | 14 ++++ kernel/trace/trace_probe_tmpl.h | 63 +++++++++++++++-- 5 files changed, 183 insertions(+), 39 deletions(-)
diff --git a/Documentation/trace/kprobetrace.txt b/Documentation/trace/kprobetrace.txt index 1d082f8ffeee..8bf752dfc072 100644 --- a/Documentation/trace/kprobetrace.txt +++ b/Documentation/trace/kprobetrace.txt @@ -65,9 +65,22 @@ in decimal ('s' and 'u') or hexadecimal ('x'). Without type casting, 'x32' or 'x64' is used depends on the architecture (e.g. x86-32 uses x32, and x86-64 uses x64).
+These value types can be an array. To record array data, you can add '[N]' +(where N is a fixed number, less than 64) to the base type. +E.g. 'x16[4]' means an array of x16 (2bytes hex) with 4 elements. +Note that the array can be applied to memory type fetchargs, you can not +apply it to registers/stack-entries etc. (for example, '$stack1:x8[8]' is +wrong, but '+8($stack):x8[8]' is OK.) + String type is a special type, which fetches a "null-terminated" string from kernel space. This means it will fail and store NULL if the string container has been paged out. +The string array type is a bit different from other types. For other base +types, <base-type>[1] is equal to <base-type> (e.g. +0(%di):x32[1] is same +as +0(%di):x32.) But string[1] is not equal to string. The string type itself +represents "char array", but string array type represents "char * array". +So, for example, +0(%di):string[1] is equal to +0(+0(%di)):string. + Bitfield is another special type, which takes 3 parameters, bit-width, bit- offset, and container-size (usually 32). The syntax is;
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index bcd1fd87082d..b7c6698265e5 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -4614,7 +4614,8 @@ static const char readme_msg[] = "\t $stack<index>, $stack, $retval, $comm\n" #endif "\t type: s8/16/32/64, u8/16/32/64, x8/16/32/64, string, symbol,\n" - "\t b<bit-width>@<bit-offset>/<container-size>\n" + "\t b<bit-width>@<bit-offset>/<container-size>,\n" + "\t <type>[<array-size>]\n" #endif " events/\t\t- Directory containing all trace event subsystems:\n" " enable\t\t- Write 0/1 to enable/disable tracing of all events\n" diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c index 84887754702a..73359d248523 100644 --- a/kernel/trace/trace_probe.c +++ b/kernel/trace/trace_probe.c @@ -363,9 +363,9 @@ static int __parse_bitfield_probe_arg(const char *bf, int traceprobe_parse_probe_arg(char *arg, ssize_t *size, struct probe_arg *parg, unsigned int flags) { - struct fetch_insn *code, *tmp = NULL; - const char *t; - int ret; + struct fetch_insn *code, *scode, *tmp = NULL; + char *t, *t2; + int ret, len;
if (strlen(arg) > MAX_ARGSTR_LEN) { pr_info("Argument is too long.: %s\n", arg); @@ -376,24 +376,42 @@ int traceprobe_parse_probe_arg(char *arg, ssize_t *size, pr_info("Failed to allocate memory for command '%s'.\n", arg); return -ENOMEM; } - t = strchr(parg->comm, ':'); + t = strchr(arg, ':'); if (t) { - arg[t - parg->comm] = '\0'; - t++; + *t = '\0'; + t2 = strchr(++t, '['); + if (t2) { + *t2 = '\0'; + parg->count = simple_strtoul(t2 + 1, &t2, 0); + if (strcmp(t2, "]") || parg->count == 0) + return -EINVAL; + if (parg->count > MAX_ARRAY_LEN) + return -E2BIG; + } } /* * The default type of $comm should be "string", and it can't be * dereferenced. */ if (!t && strcmp(arg, "$comm") == 0) - t = "string"; - parg->type = find_fetch_type(t); + parg->type = find_fetch_type("string"); + else + parg->type = find_fetch_type(t); if (!parg->type) { pr_info("Unsupported type: %s\n", t); return -EINVAL; } parg->offset = *size; - *size += parg->type->size; + *size += parg->type->size * (parg->count ?: 1); + + if (parg->count) { + len = strlen(parg->type->fmttype) + 6; + parg->fmt = kmalloc(len, GFP_KERNEL); + if (!parg->fmt) + return -ENOMEM; + snprintf(parg->fmt, len, "%s[%d]", parg->type->fmttype, + parg->count); + }
code = tmp = kzalloc(sizeof(*code) * FETCH_INSN_MAX, GFP_KERNEL); if (!code) @@ -413,10 +431,20 @@ int traceprobe_parse_probe_arg(char *arg, ssize_t *size, ret = -EINVAL; goto fail; } - /* Since IMM or COMM must be the 1st insn, this is safe */ - if (code->op == FETCH_OP_IMM || code->op == FETCH_OP_COMM) + if (code->op != FETCH_OP_DEREF || parg->count) { + /* + * IMM and COMM is pointing actual address, those must + * be kept, and if parg->count != 0, this is an array + * of string pointers instead of string address itself. + */ code++; + if (code->op != FETCH_OP_NOP) { + ret = -E2BIG; + goto fail; + } + } code->op = FETCH_OP_ST_STRING; /* In DEREF case, replace it */ + code->size = parg->type->size; parg->dynamic = true; } else if (code->op == FETCH_OP_DEREF) { code->op = FETCH_OP_ST_MEM; @@ -430,12 +458,29 @@ int traceprobe_parse_probe_arg(char *arg, ssize_t *size, code->op = FETCH_OP_ST_RAW; code->size = parg->type->size; } + scode = code; /* Modify operation */ if (t != NULL) { ret = __parse_bitfield_probe_arg(t, parg->type, &code); if (ret) goto fail; } + /* Loop(Array) operation */ + if (parg->count) { + if (scode->op != FETCH_OP_ST_MEM && + scode->op != FETCH_OP_ST_STRING) { + pr_info("array only accepts memory or address\n"); + ret = -EINVAL; + goto fail; + } + code++; + if (code->op != FETCH_OP_NOP) { + ret = -E2BIG; + goto fail; + } + code->op = FETCH_OP_LP_ARRAY; + code->param = parg->count; + } code++; code->op = FETCH_OP_END;
@@ -474,14 +519,17 @@ void traceprobe_free_probe_arg(struct probe_arg *arg) kfree(arg->code); kfree(arg->name); kfree(arg->comm); + kfree(arg->fmt); }
+/* When len=0, we just calculate the needed length */ +#define LEN_OR_ZERO (len ? len - pos : 0) static int __set_print_fmt(struct trace_probe *tp, char *buf, int len, bool is_return) { - int i; + struct probe_arg *parg; + int i, j; int pos = 0; - const char *fmt, *arg;
if (!is_return) { @@ -492,33 +540,49 @@ static int __set_print_fmt(struct trace_probe *tp, char *buf, int len, arg = "REC->" FIELD_STRING_FUNC ", REC->" FIELD_STRING_RETIP; }
- /* When len=0, we just calculate the needed length */ -#define LEN_OR_ZERO (len ? len - pos : 0) - pos += snprintf(buf + pos, LEN_OR_ZERO, ""%s", fmt);
for (i = 0; i < tp->nr_args; i++) { - pos += snprintf(buf + pos, LEN_OR_ZERO, " %s=%s", - tp->args[i].name, tp->args[i].type->fmt); + parg = tp->args + i; + pos += snprintf(buf + pos, LEN_OR_ZERO, " %s=", parg->name); + if (parg->count) { + pos += snprintf(buf + pos, LEN_OR_ZERO, "{%s", + parg->type->fmt); + for (j = 1; j < parg->count; j++) + pos += snprintf(buf + pos, LEN_OR_ZERO, ",%s", + parg->type->fmt); + pos += snprintf(buf + pos, LEN_OR_ZERO, "}"); + } else + pos += snprintf(buf + pos, LEN_OR_ZERO, "%s", + parg->type->fmt); }
pos += snprintf(buf + pos, LEN_OR_ZERO, "", %s", arg);
for (i = 0; i < tp->nr_args; i++) { - if (strcmp(tp->args[i].type->name, "string") == 0) + parg = tp->args + i; + if (parg->count) { + if (strcmp(parg->type->name, "string") == 0) + fmt = ", __get_str(%s[%d])"; + else + fmt = ", REC->%s[%d]"; + for (j = 0; j < parg->count; j++) + pos += snprintf(buf + pos, LEN_OR_ZERO, + fmt, parg->name, j); + } else { + if (strcmp(parg->type->name, "string") == 0) + fmt = ", __get_str(%s)"; + else + fmt = ", REC->%s"; pos += snprintf(buf + pos, LEN_OR_ZERO, - ", __get_str(%s)", - tp->args[i].name); - else - pos += snprintf(buf + pos, LEN_OR_ZERO, ", REC->%s", - tp->args[i].name); + fmt, parg->name); + } }
-#undef LEN_OR_ZERO - /* return the length of print_fmt */ return pos; } +#undef LEN_OR_ZERO
int traceprobe_set_print_fmt(struct trace_probe *tp, bool is_return) { @@ -546,11 +610,16 @@ int traceprobe_define_arg_fields(struct trace_event_call *event_call, /* Set argument names as fields */ for (i = 0; i < tp->nr_args; i++) { struct probe_arg *parg = &tp->args[i]; - - ret = trace_define_field(event_call, parg->type->fmttype, - parg->name, + const char *fmt = parg->type->fmttype; + int size = parg->type->size; + + if (parg->fmt) + fmt = parg->fmt; + if (parg->count) + size *= parg->count; + ret = trace_define_field(event_call, fmt, parg->name, offset + parg->offset, - parg->type->size, + parg->type->size * parg->count, parg->type->is_signed, FILTER_OTHER); if (ret) diff --git a/kernel/trace/trace_probe.h b/kernel/trace/trace_probe.h index ff91faf70887..d256a19ee6d1 100644 --- a/kernel/trace/trace_probe.h +++ b/kernel/trace/trace_probe.h @@ -43,6 +43,7 @@
#define MAX_TRACE_ARGS 128 #define MAX_ARGSTR_LEN 63 +#define MAX_ARRAY_LEN 64 #define MAX_STRING_SIZE PATH_MAX
/* Reserved field names */ @@ -78,6 +79,14 @@ static nokprobe_inline void *get_loc_data(u32 *dl, void *ent) return (u8 *)ent + get_loc_offs(*dl); }
+static nokprobe_inline u32 update_data_loc(u32 loc, int consumed) +{ + u32 maxlen = get_loc_len(loc); + u32 offset = get_loc_offs(loc); + + return make_data_loc(maxlen - consumed, offset + consumed); +} + /* Printing function type */ typedef int (*print_type_func_t)(struct trace_seq *, void *, void *);
@@ -100,6 +109,8 @@ enum fetch_op { FETCH_OP_ST_STRING, /* String: .offset, .size */ // Stage 4 (modify) op FETCH_OP_MOD_BF, /* Bitfield: .basesize, .lshift, .rshift */ + // Stage 5 (loop) op + FETCH_OP_LP_ARRAY, /* Array: .param = loop count */ FETCH_OP_END, };
@@ -189,6 +200,7 @@ DECLARE_BASIC_PRINT_TYPE_FUNC(symbol); _ASSIGN_FETCH_TYPE(#ptype, ptype, ftype, sizeof(ftype), sign, atype)
#define ASSIGN_FETCH_TYPE_END {} +#define MAX_ARRAY_LEN 64
#ifdef CONFIG_KPROBE_EVENTS bool trace_kprobe_on_func_entry(struct trace_event_call *call); @@ -209,8 +221,10 @@ struct probe_arg { struct fetch_insn *code; bool dynamic;/* Dynamic array (string) is used */ unsigned int offset; /* Offset from argument entry */ + unsigned int count; /* Array count */ const char *name; /* Name of this argument */ const char *comm; /* Command of this argument */ + char *fmt; /* Format string if needed */ const struct fetch_type *type; /* Type of this argument */ };
diff --git a/kernel/trace/trace_probe_tmpl.h b/kernel/trace/trace_probe_tmpl.h index 32ae2fc78190..edc09f2cd6b2 100644 --- a/kernel/trace/trace_probe_tmpl.h +++ b/kernel/trace/trace_probe_tmpl.h @@ -67,10 +67,15 @@ static nokprobe_inline int process_fetch_insn_bottom(struct fetch_insn *code, unsigned long val, void *dest, void *base) { - int ret = 0; + struct fetch_insn *s3 = NULL; + int total = 0, ret = 0, i = 0; + u32 loc = 0; + unsigned long lval = val;
+stage2: /* 2nd stage: dereference memory if needed */ while (code->op == FETCH_OP_DEREF) { + lval = val; ret = probe_mem_read(&val, (void *)val + code->offset, sizeof(val)); if (ret) @@ -78,11 +83,15 @@ process_fetch_insn_bottom(struct fetch_insn *code, unsigned long val, code++; }
+ s3 = code; +stage3: /* 3rd stage: store value to buffer */ if (unlikely(!dest)) { - if (code->op == FETCH_OP_ST_STRING) - return fetch_store_strlen(val + code->offset); - else + if (code->op == FETCH_OP_ST_STRING) { + ret += fetch_store_strlen(val + code->offset); + code++; + goto array; + } else return -EILSEQ; }
@@ -94,6 +103,7 @@ process_fetch_insn_bottom(struct fetch_insn *code, unsigned long val, probe_mem_read(dest, (void *)val + code->offset, code->size); break; case FETCH_OP_ST_STRING: + loc = *(u32 *)dest; ret = fetch_store_string(val + code->offset, dest, base); break; default: @@ -107,6 +117,29 @@ process_fetch_insn_bottom(struct fetch_insn *code, unsigned long val, code++; }
+array: + /* the last stage: Loop on array */ + if (code->op == FETCH_OP_LP_ARRAY) { + total += ret; + if (++i < code->param) { + code = s3; + if (s3->op != FETCH_OP_ST_STRING) { + dest += s3->size; + val += s3->size; + goto stage3; + } + code--; + val = lval + sizeof(char *); + if (dest) { + dest += sizeof(u32); + *(u32 *)dest = update_data_loc(loc, ret); + } + goto stage2; + } + code++; + ret = total; + } + return code->op == FETCH_OP_END ? ret : -EILSEQ; }
@@ -156,12 +189,26 @@ static inline int print_probe_args(struct trace_seq *s, struct probe_arg *args, int nr_args, u8 *data, void *field) { - int i; + void *p; + int i, j;
for (i = 0; i < nr_args; i++) { - trace_seq_printf(s, " %s=", args[i].name); - if (!args[i].type->print(s, data + args[i].offset, field)) - return -ENOMEM; + struct probe_arg *a = args + i; + + trace_seq_printf(s, " %s=", a->name); + if (likely(!a->count)) { + if (!a->type->print(s, data + a->offset, field)) + return -ENOMEM; + continue; + } + trace_seq_putc(s, '{'); + p = data + a->offset; + for (j = 0; j < a->count; j++) { + if (!a->type->print(s, p, field)) + return -ENOMEM; + trace_seq_putc(s, j == a->count - 1 ? '}' : ','); + p += a->type->size; + } } return 0; }
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Add a testcase for symbol type with kprobe event. This tests good/bad syntax combinations and also the traced data. If the kernel doesn't support symbol type, it skips the test as UNSUPPORTED.
Signed-off-by: Masami Hiramatsu mhiramat@kernel.org --- Changes in v3: - Use IP/PC register to test the symbol type --- .../ftrace/test.d/kprobe/kprobe_args_symbol.tc | 77 ++++++++++++++++++++ 1 file changed, 77 insertions(+) create mode 100644 tools/testing/selftests/ftrace/test.d/kprobe/kprobe_args_symbol.tc
diff --git a/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_args_symbol.tc b/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_args_symbol.tc new file mode 100644 index 000000000000..20a8664a838b --- /dev/null +++ b/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_args_symbol.tc @@ -0,0 +1,77 @@ +#!/bin/sh +# SPDX-License-Identifier: GPL-2.0 +# description: Kprobe event argument symbol type + +[ -f kprobe_events ] || exit_unsupported # this is configurable + +grep -qe "type:.* symbol" README || exit_unsupported # version issue + +echo 0 > events/enable +echo > kprobe_events + +PROBEFUNC="vfs_read" +GOODREG= +BADREG= +REG= +GOODSYM="_sdata" +if ! grep -qw ${GOODSYM} /proc/kallsyms ; then + GOODSYM=$PROBEFUNC +fi + +case `uname -m` in +x86_64|i[3456]86) + GOODREG=%ax + BADREG=%ex + REG=%ip +;; +aarch64) + GOODREG=%x0 + BADREG=%ax + REG=%pc +;; +arm*) + GOODREG=%r0 + BADREG=%ax + REG=%pc +;; +*) + echo "Please implement other architecture here" + exit_untested +esac + +test_goodarg() # Good-args +{ + while [ "$1" ]; do + echo "p ${PROBEFUNC} $1" > kprobe_events + shift 1 + done; +} + +test_badarg() # Bad-args +{ + while [ "$1" ]; do + ! echo "p ${PROBEFUNC} $1" > kprobe_events + shift 1 + done; +} + +echo > kprobe_events + +: "Symbol type" +test_goodarg "${GOODREG}:symbol" "@${GOODSYM}:symbol" "@${GOODSYM}+10:symbol" \ + "$stack0:symbol" "+0($stack):symbol" +test_badarg "$comm:symbol" + +: "Retval with symbol type" +echo "r ${PROBEFUNC} $retval:symbol" > kprobe_events + +echo > kprobe_events + +: "Test get symbol" +echo "p:testprobe create_trace_kprobe ${REG}:symbol" > kprobe_events +echo 1 > events/kprobes/testprobe/enable +! echo test >> kprobe_events +tail -n 1 trace | grep -q "arg1=create_trace_kprobe" + +echo 0 > events/enable +echo > kprobe_events
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Add a testcase for array type with kprobe event. This tests whether the traced data is correct or not. If the kernel doesn't support array type, it skips the test as UNSUPPORTED.
Signed-off-by: Masami Hiramatsu mhiramat@kernel.org --- .../ftrace/test.d/kprobe/kprobe_args_argN.tc | 25 ++++++++++++++++++++ 1 file changed, 25 insertions(+) create mode 100644 tools/testing/selftests/ftrace/test.d/kprobe/kprobe_args_argN.tc
diff --git a/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_args_argN.tc b/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_args_argN.tc new file mode 100644 index 000000000000..d5c5c8c3a51e --- /dev/null +++ b/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_args_argN.tc @@ -0,0 +1,25 @@ +#!/bin/sh +# SPDX-License-Identifier: GPL-2.0 +# description: Kprobe event argN argument + +[ -f kprobe_events ] || exit_unsupported # this is configurable + +grep -q "arg<N>" README || exit_unsupported # version issue + +echo 0 > events/enable +echo > kprobe_events + +: "Test bad pattern : arg0 is not allowed" +! echo 'p:testprobe create_trace_kprobe $arg0' > kprobe_events + +: "Test get argument" +echo 'p:testprobe create_trace_kprobe $arg1' > kprobe_events +echo 1 > events/kprobes/testprobe/enable +! echo test >> kprobe_events +tail -n 1 trace | grep -qe "testprobe.* arg1=0x1" + +! echo test test test >> kprobe_events +tail -n 1 trace | grep -qe "testprobe.* arg1=0x3" + +echo 0 > events/enable +echo > kprobe_events
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Add a testcase for array type with kprobe event. This tests good/bad syntax combinations and also the traced data is correct in several way. If the kernel doesn't support array type, it skips the test as UNSUPPORTED.
Signed-off-by: Masami Hiramatsu mhiramat@kernel.org --- .../ftrace/test.d/kprobe/kprobe_args_array.tc | 75 ++++++++++++++++++++ 1 file changed, 75 insertions(+) create mode 100644 tools/testing/selftests/ftrace/test.d/kprobe/kprobe_args_array.tc
diff --git a/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_args_array.tc b/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_args_array.tc new file mode 100644 index 000000000000..27c9628c1fff --- /dev/null +++ b/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_args_array.tc @@ -0,0 +1,75 @@ +#!/bin/sh +# SPDX-License-Identifier: GPL-2.0 +# description: Kprobe event array argument + +[ -f kprobe_events ] || exit_unsupported # this is configurable + +grep -q "<type>[<array-size>]" README || exit_unsupported # version issue + +GOODSYM="_sdata" +if ! grep -qw ${GOODSYM} /proc/kallsyms ; then + GOODSYM="create_trace_kprobe" +fi +case `uname -m` in +x86_64) + ARG2=%si + OFFS=8 +;; +i[3456]86) + ARG2=%cx + OFFS=4 +;; +aarch64) + ARG2=%x1 + OFFS=8 +;; +arm*) + ARG2=%r1 + OFFS=4 +;; +*) + echo "Please implement other architecture here" + exit_untested +esac + +create_testprobe() { # args + echo "p:testprobe create_trace_kprobe $*" > kprobe_events +} + +echo 0 > events/enable +echo > kprobe_events + +: "Syntax test" +create_testprobe "+0(${ARG2}):x8[1] +0(${ARG2}):s16[1] +0(${ARG2}):u32[1]" +create_testprobe "+0(${ARG2}):x64[1] +0(${ARG2}):symbol[1]" +create_testprobe "+0(${ARG2}):b2@3/8[1] +0(${ARG2}):string[1]" +create_testprobe "+0(${ARG2}):x8[64] @${GOODSYM}:x8[4]" + +! create_testprobe "${ARG2}:x8[1]" # Can not use array type on register +! create_testprobe "$comm:x8[1]" # Can not use array type on $comm +! create_testprobe "$comm:string[1]" # No, even if it is string array +! create_testprobe "+0(${ARG2}):x64[0]" # array size >= 1 +! create_testprobe "+0(${ARG2}):x64[65]" # array size <= 64 + +: "Test get argument (1)" +create_testprobe "arg1=+0(${ARG2}):string[1]" > kprobe_events +echo 1 > events/kprobes/testprobe/enable +! echo test >> kprobe_events +tail -n 1 trace | grep -qe "testprobe.* arg1={"test"}" +echo 0 > events/kprobes/testprobe/enable + +: "Test get argument (2)" +create_testprobe "arg1=+0(${ARG2}):string[3]" > kprobe_events +echo 1 > events/kprobes/testprobe/enable +! echo foo bar buzz >> kprobe_events +tail -n 1 trace | grep -qe "testprobe.* arg1={"foo","bar","buzz"}" +echo 0 > events/kprobes/testprobe/enable + +: "Test get argument (3)" +create_testprobe "arg1=+0(+0(${ARG2})):u8[4]" > kprobe_events +echo 1 > events/kprobes/testprobe/enable +! echo 1234 >> kprobe_events +tail -n 1 trace | grep -qe "testprobe.* arg1={49,50,51,52}" # ascii code +echo 0 > events/kprobes/testprobe/enable + +echo > kprobe_events
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Hi Masami,
On Sat, Feb 24, 2018 at 02:28:52PM +0900, Masami Hiramatsu wrote:
In Documentation/trace/kprobetrace.txt, it says
@SYM[+|-offs] : Fetch memory at SYM +|- offs (SYM should be a data symbol)
However, the parser doesn't parse minus offset correctly, since commit 2fba0c8867af ("tracing/kprobes: Fix probe offset to be unsigned") drops minus ("-") offset support for kprobe probe address usage.
This fixes the traceprobe_split_symbol_offset() to parse minus offset again with checking the offset range, and add a minus offset check in kprobe probe address usage.
Fixes: 2fba0c8867af ("tracing/kprobes: Fix probe offset to be unsigned") Signed-off-by: Masami Hiramatsu mhiramat@kernel.org
Changes in v3:
- Use kstrtol instead of kstrtoul. (Thanks Namhyung!)
kernel/trace/trace_kprobe.c | 4 ++-- kernel/trace/trace_probe.c | 8 +++----- kernel/trace/trace_probe.h | 2 +- 3 files changed, 6 insertions(+), 8 deletions(-)
diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c index 5ce9b8cf7be3..b5b1d8aa47d6 100644 --- a/kernel/trace/trace_kprobe.c +++ b/kernel/trace/trace_kprobe.c @@ -667,7 +667,7 @@ static int create_trace_kprobe(int argc, char **argv) char *symbol = NULL, *event = NULL, *group = NULL; int maxactive = 0; char *arg;
- unsigned long offset = 0;
- long offset = 0; void *addr = NULL; char buf[MAX_EVENT_NAME_LEN];
@@ -755,7 +755,7 @@ static int create_trace_kprobe(int argc, char **argv) symbol = argv[1]; /* TODO: support .init module functions */ ret = traceprobe_split_symbol_offset(symbol, &offset);
if (ret) {
if (ret || offset < 0) {
Hmm.. is minus offset an error? Then why not removing it from the documentation? And the 'ret' would be 0 in that case.
pr_info("Failed to parse either an address or a symbol.\n"); return ret; }
diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c index d59357308677..d3d1ee820336 100644 --- a/kernel/trace/trace_probe.c +++ b/kernel/trace/trace_probe.c @@ -320,7 +320,7 @@ static fetch_func_t get_fetch_size_function(const struct fetch_type *type, } /* Split symbol and offset. */ -int traceprobe_split_symbol_offset(char *symbol, unsigned long *offset) +int traceprobe_split_symbol_offset(char *symbol, long *offset) { char *tmp; int ret; @@ -328,13 +328,11 @@ int traceprobe_split_symbol_offset(char *symbol, unsigned long *offset) if (!offset) return -EINVAL;
- tmp = strchr(symbol, '+');
- tmp = strpbrk(symbol, "+-"); if (tmp) {
/* skip sign because kstrtoul doesn't accept '+' */
ret = kstrtoul(tmp + 1, 0, offset);
ret = kstrtol(tmp + 1, 0, offset);
It should not skip the sign anymore.
Thanks, Namhyung
if (ret) return ret;
- *tmp = '\0'; } else *offset = 0;
diff --git a/kernel/trace/trace_probe.h b/kernel/trace/trace_probe.h index 0745f895f780..75daff22ccea 100644 --- a/kernel/trace/trace_probe.h +++ b/kernel/trace/trace_probe.h @@ -365,7 +365,7 @@ extern int traceprobe_conflict_field_name(const char *name, extern void traceprobe_update_arg(struct probe_arg *arg); extern void traceprobe_free_probe_arg(struct probe_arg *arg); -extern int traceprobe_split_symbol_offset(char *symbol, unsigned long *offset); +extern int traceprobe_split_symbol_offset(char *symbol, long *offset); /* Sum up total data length for dynamic arraies (strings) */ static nokprobe_inline int
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On Sat, Feb 24, 2018 at 02:35:40PM +0900, Masami Hiramatsu wrote:
Add array type support for probe events. This allows user to get arraied types from memory address. The array type syntax is
TYPE[N]
Where TYPE is one of types (u8/16/32/64,s8/16/32/64, x8/16/32/64, symbol, string) and N is a fixed value less than 64.
The string array type is a bit different from other types. For other base types, <base-type>[1] is equal to <base-type> (e.g. +0(%di):x32[1] is same as +0(%di):x32.) But string[1] is not equal to string. The string type itself represents "char array", but string array type represents "char * array". So, for example, +0(%di):string[1] is equal to +0(+0(%di)):string.
Signed-off-by: Masami Hiramatsu mhiramat@kernel.org
Changes in v2:
- Add array description in README file
- Fix to init s3 code out of loop.
- Fix to proceed code when the last code is OP_ARRAY.
- Add string array type and bitfield array type.
[SNIP]
@@ -546,11 +610,16 @@ int traceprobe_define_arg_fields(struct trace_event_call *event_call, /* Set argument names as fields */ for (i = 0; i < tp->nr_args; i++) { struct probe_arg *parg = &tp->args[i];
ret = trace_define_field(event_call, parg->type->fmttype,
parg->name,
const char *fmt = parg->type->fmttype;
int size = parg->type->size;
if (parg->fmt)
fmt = parg->fmt;
if (parg->count)
size *= parg->count;
ret = trace_define_field(event_call, fmt, parg->name, offset + parg->offset,
parg->type->size,
parg->type->size * parg->count,
It should use the 'size' variable, otherwise scalar types will have 0 size.
Thanks, Namhyung
parg->type->is_signed, FILTER_OTHER);
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On Mon, 26 Feb 2018 10:45:32 +0900 Namhyung Kim namhyung@kernel.org wrote:
On Sat, Feb 24, 2018 at 02:35:40PM +0900, Masami Hiramatsu wrote:
Add array type support for probe events. This allows user to get arraied types from memory address. The array type syntax is
TYPE[N]
Where TYPE is one of types (u8/16/32/64,s8/16/32/64, x8/16/32/64, symbol, string) and N is a fixed value less than 64.
The string array type is a bit different from other types. For other base types, <base-type>[1] is equal to <base-type> (e.g. +0(%di):x32[1] is same as +0(%di):x32.) But string[1] is not equal to string. The string type itself represents "char array", but string array type represents "char * array". So, for example, +0(%di):string[1] is equal to +0(+0(%di)):string.
Signed-off-by: Masami Hiramatsu mhiramat@kernel.org
Changes in v2:
- Add array description in README file
- Fix to init s3 code out of loop.
- Fix to proceed code when the last code is OP_ARRAY.
- Add string array type and bitfield array type.
[SNIP]
@@ -546,11 +610,16 @@ int traceprobe_define_arg_fields(struct trace_event_call *event_call, /* Set argument names as fields */ for (i = 0; i < tp->nr_args; i++) { struct probe_arg *parg = &tp->args[i];
ret = trace_define_field(event_call, parg->type->fmttype,
parg->name,
const char *fmt = parg->type->fmttype;
int size = parg->type->size;
if (parg->fmt)
fmt = parg->fmt;
if (parg->count)
size *= parg->count;
ret = trace_define_field(event_call, fmt, parg->name, offset + parg->offset,
parg->type->size,
parg->type->size * parg->count,
It should use the 'size' variable, otherwise scalar types will have 0 size.
Oops, good catch! I forgot to use it at the main point...
Thank you so much!
Thanks, Namhyung
parg->type->is_signed, FILTER_OTHER);
On Mon, 26 Feb 2018 09:38:18 +0900 Namhyung Kim namhyung@kernel.org wrote:
Hi Masami,
On Sat, Feb 24, 2018 at 02:28:52PM +0900, Masami Hiramatsu wrote:
In Documentation/trace/kprobetrace.txt, it says
@SYM[+|-offs] : Fetch memory at SYM +|- offs (SYM should be a data symbol)
However, the parser doesn't parse minus offset correctly, since commit 2fba0c8867af ("tracing/kprobes: Fix probe offset to be unsigned") drops minus ("-") offset support for kprobe probe address usage.
This fixes the traceprobe_split_symbol_offset() to parse minus offset again with checking the offset range, and add a minus offset check in kprobe probe address usage.
Fixes: 2fba0c8867af ("tracing/kprobes: Fix probe offset to be unsigned") Signed-off-by: Masami Hiramatsu mhiramat@kernel.org
Changes in v3:
- Use kstrtol instead of kstrtoul. (Thanks Namhyung!)
kernel/trace/trace_kprobe.c | 4 ++-- kernel/trace/trace_probe.c | 8 +++----- kernel/trace/trace_probe.h | 2 +- 3 files changed, 6 insertions(+), 8 deletions(-)
diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c index 5ce9b8cf7be3..b5b1d8aa47d6 100644 --- a/kernel/trace/trace_kprobe.c +++ b/kernel/trace/trace_kprobe.c @@ -667,7 +667,7 @@ static int create_trace_kprobe(int argc, char **argv) char *symbol = NULL, *event = NULL, *group = NULL; int maxactive = 0; char *arg;
- unsigned long offset = 0;
- long offset = 0; void *addr = NULL; char buf[MAX_EVENT_NAME_LEN];
@@ -755,7 +755,7 @@ static int create_trace_kprobe(int argc, char **argv) symbol = argv[1]; /* TODO: support .init module functions */ ret = traceprobe_split_symbol_offset(symbol, &offset);
if (ret) {
if (ret || offset < 0) {
Hmm.. is minus offset an error? Then why not removing it from the documentation? And the 'ret' would be 0 in that case.
Yes, since the kprobe.offset is unsigned, it is not possible. BTW, I found it is "unsigned int", so it should check UINT_MAX too... (Or make it unsigned long)
pr_info("Failed to parse either an address or a symbol.\n"); return ret; }
diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c index d59357308677..d3d1ee820336 100644 --- a/kernel/trace/trace_probe.c +++ b/kernel/trace/trace_probe.c @@ -320,7 +320,7 @@ static fetch_func_t get_fetch_size_function(const struct fetch_type *type, } /* Split symbol and offset. */ -int traceprobe_split_symbol_offset(char *symbol, unsigned long *offset) +int traceprobe_split_symbol_offset(char *symbol, long *offset) { char *tmp; int ret; @@ -328,13 +328,11 @@ int traceprobe_split_symbol_offset(char *symbol, unsigned long *offset) if (!offset) return -EINVAL;
- tmp = strchr(symbol, '+');
- tmp = strpbrk(symbol, "+-"); if (tmp) {
/* skip sign because kstrtoul doesn't accept '+' */
ret = kstrtoul(tmp + 1, 0, offset);
ret = kstrtol(tmp + 1, 0, offset);
It should not skip the sign anymore.
Oops, yes. I'll fix it and I should add a test case for it. Thanks!
Thanks, Namhyung
if (ret) return ret;
- *tmp = '\0'; } else *offset = 0;
diff --git a/kernel/trace/trace_probe.h b/kernel/trace/trace_probe.h index 0745f895f780..75daff22ccea 100644 --- a/kernel/trace/trace_probe.h +++ b/kernel/trace/trace_probe.h @@ -365,7 +365,7 @@ extern int traceprobe_conflict_field_name(const char *name, extern void traceprobe_update_arg(struct probe_arg *arg); extern void traceprobe_free_probe_arg(struct probe_arg *arg); -extern int traceprobe_split_symbol_offset(char *symbol, unsigned long *offset); +extern int traceprobe_split_symbol_offset(char *symbol, long *offset); /* Sum up total data length for dynamic arraies (strings) */ static nokprobe_inline int
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