From: Masami Hiramatsu (Google) mhiramat@kernel.org

With CONFIG_DEBUG_INFO_BTF=y and PAHOLE_HAS_BTF_TAG=y, `__user` is converted to `__attribute((btf_type_tag("user")))`. In this case, some syscall events have `const char __attribute(...) *` for __user string, like below;

/sys/kernel/tracing # cat events/syscalls/sys_enter_openat/format name: sys_enter_openat ID: 720 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:int __syscall_nr; offset:8; size:4; signed:1; field:int dfd; offset:16; size:8; signed:0; field:const char __attribute__((btf_type_tag("user"))) * filename; offset:24; size:8; signed:0; field:int flags; offset:32; size:8; signed:0; field:umode_t mode; offset:40; size:8; signed:0;

Then the trace event filter failes to set string acceptable flag (FILTER_PTR_STRING) and rejects setting string filter;

# echo 'filename.ustring ~ "*ftracetest-dir.wbx24v*"' >> events/syscalls/sys_enter_openat/filter sh: write error: Invalid argument # cat error_log [ 723.743637] event filter parse error: error: Expecting numeric field Command: filename.ustring ~ "*ftracetest-dir.wbx24v*"

Handle "(const) char __attribute() *" also as string ptr type.

Signed-off-by: Masami Hiramatsu (Google) mhiramat@kernel.org --- kernel/trace/trace_events_filter.c | 5 +++++ 1 file changed, 5 insertions(+)

diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c index 3885aadc434d..5e27190a0377 100644 --- a/kernel/trace/trace_events_filter.c +++ b/kernel/trace/trace_events_filter.c @@ -1488,6 +1488,11 @@ int filter_assign_type(const char *type) if (strcmp(type, "char *") == 0 || strcmp(type, "const char *") == 0) return FILTER_PTR_STRING;

+ /* Ignore attributes */ + if (glob_match("char __attribute(*) \*", type) || + glob_match("const char __attribute(*) \*", type)) + return FILTER_PTR_STRING; + return FILTER_OTHER; }

From: Masami Hiramatsu (Google) mhiramat@kernel.org

Since commit c5b6ababd21a ("locking/mutex: implement mutex_trylock_nested") makes mutex_trylock() as an inlined function if CONFIG_DEBUG_LOCK_ALLOC=y, we can not use mutex_trylock() for testing the glob filter of ftrace.

Use mutex_unlock instead.

Signed-off-by: Masami Hiramatsu (Google) mhiramat@kernel.org --- .../ftrace/test.d/ftrace/func-filter-glob.tc | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/testing/selftests/ftrace/test.d/ftrace/func-filter-glob.tc b/tools/testing/selftests/ftrace/test.d/ftrace/func-filter-glob.tc index 4b994b6df5ac..ed81eaf2afd6 100644 --- a/tools/testing/selftests/ftrace/test.d/ftrace/func-filter-glob.tc +++ b/tools/testing/selftests/ftrace/test.d/ftrace/func-filter-glob.tc @@ -29,7 +29,7 @@ ftrace_filter_check 'schedule*' '^schedule.*$' ftrace_filter_check '*pin*lock' '.*pin.*lock$'

# filter by start*mid* -ftrace_filter_check 'mutex*try*' '^mutex.*try.*' +ftrace_filter_check 'mutex*unl*' '^mutex.*unl.*'

# Advanced full-glob matching feature is recently supported. # Skip the tests if we are sure the kernel does not support it.