On ARM the debug info is not present in the .eh_frame sections but in .debug_frame instead, in dwarf format.
This patch set uses libunwind to load and parse the dwarf debug info from the .debug_frame section if no .eh_frame_hdr section is found; also it sets the hooks in the perf_regs and libunwind code for ARMv7.
Dependencies: . if present, libunwind >= 1.1 is needed to prevent a segfault when parsing the dwarf info, . libunwind needs to be configured with --enable-debug-frame. Note: --enable-debug-frame is automatically selected on ARM.
The generated perf binary has been tested on ARMv7 (OMAP4, Marvell Armada XP) and x86_64, using the following commands: perf record -g [dwarf] -- <binary> perf report --sort symbol --call-graph --stdio
Jean Pihet (2): perf tools: Check libunwind for availability of dwarf parsing feature perf: parse the .debug_frame section in case .eh_frame is not present
Will Deacon (2): ARM: perf: add support for perf registers API ARM: perf: wire up perf_regs and unwind support for ARM
arch/arm/Kconfig | 2 + arch/arm/include/uapi/asm/Kbuild | 1 + arch/arm/include/uapi/asm/perf_regs.h | 23 ++++++++++ arch/arm/kernel/Makefile | 1 + arch/arm/kernel/perf_regs.c | 30 +++++++++++++ tools/perf/arch/arm/Makefile | 3 ++ tools/perf/arch/arm/include/perf_regs.h | 54 ++++++++++++++++++++++++ tools/perf/arch/arm/util/unwind.c | 48 +++++++++++++++++++++ tools/perf/config/Makefile | 13 ++++-- tools/perf/config/feature-tests.mak | 21 ++++++++- tools/perf/util/unwind.c | 75 ++++++++++++++++++++++++++------- 11 files changed, 251 insertions(+), 20 deletions(-) create mode 100644 arch/arm/include/uapi/asm/perf_regs.h create mode 100644 arch/arm/kernel/perf_regs.c create mode 100644 tools/perf/arch/arm/include/perf_regs.h create mode 100644 tools/perf/arch/arm/util/unwind.c
From: Will Deacon will.deacon@arm.com
This patch implements the functions required for the perf registers API, allowing the perf tool to interface kernel register dumps with libunwind in order to provide userspace backtracing.
Signed-off-by: Will Deacon will.deacon@arm.com Cc: Jean Pihet jean.pihet@linaro.org --- arch/arm/Kconfig | 2 ++ arch/arm/include/uapi/asm/Kbuild | 1 + arch/arm/include/uapi/asm/perf_regs.h | 23 +++++++++++++++++++++++ arch/arm/kernel/Makefile | 1 + arch/arm/kernel/perf_regs.c | 30 ++++++++++++++++++++++++++++++ 5 files changed, 57 insertions(+) create mode 100644 arch/arm/include/uapi/asm/perf_regs.h create mode 100644 arch/arm/kernel/perf_regs.c
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index 3f7714d..5595888 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -51,6 +51,8 @@ config ARM select HAVE_MOD_ARCH_SPECIFIC if ARM_UNWIND select HAVE_OPROFILE if (HAVE_PERF_EVENTS) select HAVE_PERF_EVENTS + select HAVE_PERF_REGS + select HAVE_PERF_USER_STACK_DUMP select HAVE_REGS_AND_STACK_ACCESS_API select HAVE_SYSCALL_TRACEPOINTS select HAVE_UID16 diff --git a/arch/arm/include/uapi/asm/Kbuild b/arch/arm/include/uapi/asm/Kbuild index 18d76fd..70a1c9d 100644 --- a/arch/arm/include/uapi/asm/Kbuild +++ b/arch/arm/include/uapi/asm/Kbuild @@ -7,6 +7,7 @@ header-y += hwcap.h header-y += ioctls.h header-y += kvm_para.h header-y += mman.h +header-y += perf_regs.h header-y += posix_types.h header-y += ptrace.h header-y += setup.h diff --git a/arch/arm/include/uapi/asm/perf_regs.h b/arch/arm/include/uapi/asm/perf_regs.h new file mode 100644 index 0000000..ce59448 --- /dev/null +++ b/arch/arm/include/uapi/asm/perf_regs.h @@ -0,0 +1,23 @@ +#ifndef _ASM_ARM_PERF_REGS_H +#define _ASM_ARM_PERF_REGS_H + +enum perf_event_arm_regs { + PERF_REG_ARM_R0, + PERF_REG_ARM_R1, + PERF_REG_ARM_R2, + PERF_REG_ARM_R3, + PERF_REG_ARM_R4, + PERF_REG_ARM_R5, + PERF_REG_ARM_R6, + PERF_REG_ARM_R7, + PERF_REG_ARM_R8, + PERF_REG_ARM_R9, + PERF_REG_ARM_R10, + PERF_REG_ARM_FP, + PERF_REG_ARM_IP, + PERF_REG_ARM_SP, + PERF_REG_ARM_LR, + PERF_REG_ARM_PC, + PERF_REG_ARM_MAX, +}; +#endif /* _ASM_ARM_PERF_REGS_H */ diff --git a/arch/arm/kernel/Makefile b/arch/arm/kernel/Makefile index 5140df5f..9b818ca 100644 --- a/arch/arm/kernel/Makefile +++ b/arch/arm/kernel/Makefile @@ -78,6 +78,7 @@ obj-$(CONFIG_CPU_XSC3) += xscale-cp0.o obj-$(CONFIG_CPU_MOHAWK) += xscale-cp0.o obj-$(CONFIG_CPU_PJ4) += pj4-cp0.o obj-$(CONFIG_IWMMXT) += iwmmxt.o +obj-$(CONFIG_PERF_EVENTS) += perf_regs.o obj-$(CONFIG_HW_PERF_EVENTS) += perf_event.o perf_event_cpu.o AFLAGS_iwmmxt.o := -Wa,-mcpu=iwmmxt obj-$(CONFIG_ARM_CPU_TOPOLOGY) += topology.o diff --git a/arch/arm/kernel/perf_regs.c b/arch/arm/kernel/perf_regs.c new file mode 100644 index 0000000..6e4379c --- /dev/null +++ b/arch/arm/kernel/perf_regs.c @@ -0,0 +1,30 @@ + +#include <linux/errno.h> +#include <linux/kernel.h> +#include <linux/perf_event.h> +#include <linux/bug.h> +#include <asm/perf_regs.h> +#include <asm/ptrace.h> + +u64 perf_reg_value(struct pt_regs *regs, int idx) +{ + if (WARN_ON_ONCE((u32)idx >= PERF_REG_ARM_MAX)) + return 0; + + return regs->uregs[idx]; +} + +#define REG_RESERVED (~((1ULL << PERF_REG_ARM_MAX) - 1)) + +int perf_reg_validate(u64 mask) +{ + if (!mask || mask & REG_RESERVED) + return -EINVAL; + + return 0; +} + +u64 perf_reg_abi(struct task_struct *task) +{ + return PERF_SAMPLE_REGS_ABI_32; +}
From: Will Deacon will.deacon@arm.com
This patch hooks in the perf_regs and libunwind code for ARM.
Signed-off-by: Will Deacon will.deacon@arm.com Cc: Jean Pihet jean.pihet@linaro.org --- tools/perf/arch/arm/Makefile | 3 ++ tools/perf/arch/arm/include/perf_regs.h | 54 +++++++++++++++++++++++++++++++++ tools/perf/arch/arm/util/unwind.c | 48 +++++++++++++++++++++++++++++ tools/perf/config/Makefile | 7 +++-- 4 files changed, 110 insertions(+), 2 deletions(-) create mode 100644 tools/perf/arch/arm/include/perf_regs.h create mode 100644 tools/perf/arch/arm/util/unwind.c
diff --git a/tools/perf/arch/arm/Makefile b/tools/perf/arch/arm/Makefile index 15130b5..fe9b61e 100644 --- a/tools/perf/arch/arm/Makefile +++ b/tools/perf/arch/arm/Makefile @@ -2,3 +2,6 @@ ifndef NO_DWARF PERF_HAVE_DWARF_REGS := 1 LIB_OBJS += $(OUTPUT)arch/$(ARCH)/util/dwarf-regs.o endif +ifndef NO_LIBUNWIND +LIB_OBJS += $(OUTPUT)arch/$(ARCH)/util/unwind.o +endif diff --git a/tools/perf/arch/arm/include/perf_regs.h b/tools/perf/arch/arm/include/perf_regs.h new file mode 100644 index 0000000..2a1cfde --- /dev/null +++ b/tools/perf/arch/arm/include/perf_regs.h @@ -0,0 +1,54 @@ +#ifndef ARCH_PERF_REGS_H +#define ARCH_PERF_REGS_H + +#include <stdlib.h> +#include "../../util/types.h" +#include <asm/perf_regs.h> + +#define PERF_REGS_MASK ((1ULL << PERF_REG_ARM_MAX) - 1) +#define PERF_REG_IP PERF_REG_ARM_PC +#define PERF_REG_SP PERF_REG_ARM_SP + +static inline const char *perf_reg_name(int id) +{ + switch (id) { + case PERF_REG_ARM_R0: + return "r0"; + case PERF_REG_ARM_R1: + return "r1"; + case PERF_REG_ARM_R2: + return "r2"; + case PERF_REG_ARM_R3: + return "r3"; + case PERF_REG_ARM_R4: + return "r4"; + case PERF_REG_ARM_R5: + return "r5"; + case PERF_REG_ARM_R6: + return "r6"; + case PERF_REG_ARM_R7: + return "r7"; + case PERF_REG_ARM_R8: + return "r8"; + case PERF_REG_ARM_R9: + return "r9"; + case PERF_REG_ARM_R10: + return "r10"; + case PERF_REG_ARM_FP: + return "fp"; + case PERF_REG_ARM_IP: + return "ip"; + case PERF_REG_ARM_SP: + return "sp"; + case PERF_REG_ARM_LR: + return "lr"; + case PERF_REG_ARM_PC: + return "pc"; + default: + return NULL; + } + + return NULL; +} + +#endif /* ARCH_PERF_REGS_H */ diff --git a/tools/perf/arch/arm/util/unwind.c b/tools/perf/arch/arm/util/unwind.c new file mode 100644 index 0000000..da3dc95 --- /dev/null +++ b/tools/perf/arch/arm/util/unwind.c @@ -0,0 +1,48 @@ + +#include <errno.h> +#include <libunwind.h> +#include "perf_regs.h" +#include "../../util/unwind.h" + +int unwind__arch_reg_id(int regnum) +{ + switch (regnum) { + case UNW_ARM_R0: + return PERF_REG_ARM_R0; + case UNW_ARM_R1: + return PERF_REG_ARM_R1; + case UNW_ARM_R2: + return PERF_REG_ARM_R2; + case UNW_ARM_R3: + return PERF_REG_ARM_R3; + case UNW_ARM_R4: + return PERF_REG_ARM_R4; + case UNW_ARM_R5: + return PERF_REG_ARM_R5; + case UNW_ARM_R6: + return PERF_REG_ARM_R6; + case UNW_ARM_R7: + return PERF_REG_ARM_R7; + case UNW_ARM_R8: + return PERF_REG_ARM_R8; + case UNW_ARM_R9: + return PERF_REG_ARM_R9; + case UNW_ARM_R10: + return PERF_REG_ARM_R10; + case UNW_ARM_R11: + return PERF_REG_ARM_FP; + case UNW_ARM_R12: + return PERF_REG_ARM_IP; + case UNW_ARM_R13: + return PERF_REG_ARM_SP; + case UNW_ARM_R14: + return PERF_REG_ARM_LR; + case UNW_ARM_R15: + return PERF_REG_ARM_PC; + default: + pr_err("unwind: invalid reg id %d\n", regnum); + return -EINVAL; + } + + return -EINVAL; +} diff --git a/tools/perf/config/Makefile b/tools/perf/config/Makefile index 214e17e..4b65710 100644 --- a/tools/perf/config/Makefile +++ b/tools/perf/config/Makefile @@ -29,6 +29,10 @@ ifeq ($(ARCH),x86_64) NO_PERF_REGS := 0 LIBUNWIND_LIBS = -lunwind -lunwind-x86_64 endif +ifeq ($(ARCH),arm) + NO_PERF_REGS := 0 + LIBUNWIND_LIBS = -lunwind -lunwind-arm +endif
ifeq ($(NO_PERF_REGS),0) CFLAGS += -DHAVE_PERF_REGS @@ -205,8 +209,7 @@ ifeq ($(call try-cc,$(SOURCE_ELF_MMAP),$(FLAGS_LIBELF),-DLIBELF_MMAP),y) endif # try-cc endif # NO_LIBELF
-# There's only x86 (both 32 and 64) support for CFI unwind so far -ifneq ($(ARCH),x86) +ifeq ($(LIBUNWIND_LIBS),) NO_LIBUNWIND := 1 endif
The newly added dwarf unwinding feature [1] requires: . a recent version (>= 1.1) of libunwind, . libunwind to be configured with --enable-debug-frame.
[1] http://www.spinics.net/lists/kernel/msg1598951.html
Add the corresponding API tests in the feature check list.
Signed-off-by: Jean Pihet jean.pihet@linaro.org --- tools/perf/config/Makefile | 6 +++++- tools/perf/config/feature-tests.mak | 21 ++++++++++++++++++++- 2 files changed, 25 insertions(+), 2 deletions(-)
diff --git a/tools/perf/config/Makefile b/tools/perf/config/Makefile index 4b65710..bbaeb04 100644 --- a/tools/perf/config/Makefile +++ b/tools/perf/config/Makefile @@ -223,9 +223,13 @@ endif
FLAGS_UNWIND=$(LIBUNWIND_CFLAGS) $(CFLAGS) $(LIBUNWIND_LDFLAGS) $(LDFLAGS) $(EXTLIBS) $(LIBUNWIND_LIBS) ifneq ($(call try-cc,$(SOURCE_LIBUNWIND),$(FLAGS_UNWIND),libunwind),y) - msg := $(warning No libunwind found, disabling post unwind support. Please install libunwind-dev[el] >= 0.99); + msg := $(warning No libunwind found, disabling post unwind support. Please install libunwind-dev[el] >= 1.1); NO_LIBUNWIND := 1 endif # Libunwind support +ifneq ($(call try-cc,$(SOURCE_LIBUNWIND_DEBUG_FRAME),$(FLAGS_UNWIND),libunwind debug_frame),y) + msg := $(warning No debug_frame support found in libunwind); +CFLAGS += -DNO_LIBUNWIND_DEBUG_FRAME +endif # debug_frame support in libunwind endif # NO_LIBUNWIND
ifndef NO_LIBUNWIND diff --git a/tools/perf/config/feature-tests.mak b/tools/perf/config/feature-tests.mak index 708fb8e..cde75f5 100644 --- a/tools/perf/config/feature-tests.mak +++ b/tools/perf/config/feature-tests.mak @@ -176,7 +176,6 @@ extern int UNW_OBJ(dwarf_search_unwind_table) (unw_addr_space_t as, unw_proc_info_t *pi, int need_unwind_info, void *arg);
- #define dwarf_search_unwind_table UNW_OBJ(dwarf_search_unwind_table)
int main(void) @@ -188,6 +187,26 @@ int main(void) return 0; } endef + +define SOURCE_LIBUNWIND_DEBUG_FRAME +#include <libunwind.h> +#include <stdlib.h> + +extern int +UNW_OBJ(dwarf_find_debug_frame) (int found, unw_dyn_info_t *di_debug, + unw_word_t ip, unw_word_t segbase, + const char *obj_name, unw_word_t start, + unw_word_t end); + +#define dwarf_find_debug_frame UNW_OBJ(dwarf_find_debug_frame) + +int main(void) +{ + dwarf_find_debug_frame(0, NULL, 0, 0, NULL, 0, 0); + return 0; +} +endef + endif
ifndef NO_BACKTRACE
On Thu, Sep 26, 2013 at 01:36:37PM +0200, Jean Pihet wrote:
The newly added dwarf unwinding feature [1] requires: . a recent version (>= 1.1) of libunwind, . libunwind to be configured with --enable-debug-frame.
[1] http://www.spinics.net/lists/kernel/msg1598951.html
Add the corresponding API tests in the feature check list.
Acked-by: Jiri Olsa jolsa@redhat.com
thanks, jirka
Hi,
On 26 September 2013 14:48, Jiri Olsa jolsa@redhat.com wrote:
On Thu, Sep 26, 2013 at 01:36:37PM +0200, Jean Pihet wrote:
The newly added dwarf unwinding feature [1] requires: . a recent version (>= 1.1) of libunwind, . libunwind to be configured with --enable-debug-frame.
[1] http://www.spinics.net/lists/kernel/msg1598951.html
Add the corresponding API tests in the feature check list.
Acked-by: Jiri Olsa jolsa@redhat.com
thanks, jirka
Thanks for the ack!
Is it possible to get an ack from the perf core maintainers? Also, is the patch going in Will's tree?
Regards, Jean
On Tue, Oct 08, 2013 at 12:44:32PM +0200, Jean Pihet wrote:
Hi,
On 26 September 2013 14:48, Jiri Olsa jolsa@redhat.com wrote:
On Thu, Sep 26, 2013 at 01:36:37PM +0200, Jean Pihet wrote:
The newly added dwarf unwinding feature [1] requires: . a recent version (>= 1.1) of libunwind, . libunwind to be configured with --enable-debug-frame.
[1] http://www.spinics.net/lists/kernel/msg1598951.html
Add the corresponding API tests in the feature check list.
Acked-by: Jiri Olsa jolsa@redhat.com
thanks, jirka
Thanks for the ack!
Is it possible to get an ack from the perf core maintainers? Also, is the patch going in Will's tree?
This being a tools patch you'd have to ask acme; also I know next to nothing about all this unwind business except that its stupid expensive ;-)
Hi,
On 8 October 2013 12:47, Peter Zijlstra peterz@infradead.org wrote:
On Tue, Oct 08, 2013 at 12:44:32PM +0200, Jean Pihet wrote:
Hi,
On 26 September 2013 14:48, Jiri Olsa jolsa@redhat.com wrote:
On Thu, Sep 26, 2013 at 01:36:37PM +0200, Jean Pihet wrote:
The newly added dwarf unwinding feature [1] requires: . a recent version (>= 1.1) of libunwind, . libunwind to be configured with --enable-debug-frame.
[1] http://www.spinics.net/lists/kernel/msg1598951.html
Add the corresponding API tests in the feature check list.
Acked-by: Jiri Olsa jolsa@redhat.com
thanks, jirka
Thanks for the ack!
Is it possible to get an ack from the perf core maintainers? Also, is the patch going in Will's tree?
This being a tools patch you'd have to ask acme; also I know next to nothing about all this unwind business except that its stupid expensive ;-)
You are right! It brings some more info on the trace though.
-- adding Arnaldo in the loop -- Arnaldo, are you OK with the changes [1]? Jiri acked the patches already; Will is willing (no pun intended) to take the ARM specific patches [2] in his tree.
[1] http://www.spinics.net/lists/kernel/msg1608921.html and http://www.spinics.net/lists/kernel/msg1608922.html [2] http://www.spinics.net/lists/kernel/msg1608920.html and http://www.spinics.net/lists/kernel/msg1608923.html
Regards, Jean
Em Tue, Oct 08, 2013 at 04:15:40PM +0200, Jean Pihet escreveu:
On 8 October 2013 12:47, Peter Zijlstra peterz@infradead.org wrote:
On Tue, Oct 08, 2013 at 12:44:32PM +0200, Jean Pihet wrote:
On 26 September 2013 14:48, Jiri Olsa jolsa@redhat.com wrote:
On Thu, Sep 26, 2013 at 01:36:37PM +0200, Jean Pihet wrote:
The newly added dwarf unwinding feature [1] requires: . a recent version (>= 1.1) of libunwind, . libunwind to be configured with --enable-debug-frame.
Add the corresponding API tests in the feature check list.
Acked-by: Jiri Olsa jolsa@redhat.com
Thanks for the ack!
Is it possible to get an ack from the perf core maintainers? Also, is the patch going in Will's tree?
This being a tools patch you'd have to ask acme; also I know next to nothing about all this unwind business except that its stupid expensive ;-)
You are right! It brings some more info on the trace though.
-- adding Arnaldo in the loop -- Arnaldo, are you OK with the changes [1]? Jiri acked the patches already; Will is willing (no pun intended) to take the ARM specific patches [2] in his tree.
As Jiri acked, go ahead and pick as much as you can via Will's tree, I'd say. :-)
- Arnaldo
[1] http://www.spinics.net/lists/kernel/msg1608921.html and http://www.spinics.net/lists/kernel/msg1608922.html [2] http://www.spinics.net/lists/kernel/msg1608920.html and http://www.spinics.net/lists/kernel/msg1608923.html
Regards, Jean
On Tue, Oct 08, 2013 at 03:28:30PM +0100, Arnaldo Carvalho de Melo wrote:
Em Tue, Oct 08, 2013 at 04:15:40PM +0200, Jean Pihet escreveu:
On 26 September 2013 14:48, Jiri Olsa jolsa@redhat.com wrote:
Acked-by: Jiri Olsa jolsa@redhat.com
-- adding Arnaldo in the loop -- Arnaldo, are you OK with the changes [1]? Jiri acked the patches already; Will is willing (no pun intended) to take the ARM specific patches [2] in his tree.
As Jiri acked, go ahead and pick as much as you can via Will's tree, I'd say. :-)
Cheers guys, that suits me!
Will
On ARM the debug info is not present in the .eh_frame sections but in .debug_frame instead, in dwarf format. Use libunwind to load and parse the debug info.
Dependencies: . if present, libunwind >= 1.1 is needed to prevent a segfault when parsing the dwarf info, . libunwind needs to be configured with --enable-debug-frame. Note: --enable-debug-frame is automatically selected on ARM.
Signed-off-by: Jean Pihet jean.pihet@linaro.org --- tools/perf/util/unwind.c | 75 +++++++++++++++++++++++++++++++++++++----------- 1 file changed, 59 insertions(+), 16 deletions(-)
diff --git a/tools/perf/util/unwind.c b/tools/perf/util/unwind.c index 2f891f7..5390d0b 100644 --- a/tools/perf/util/unwind.c +++ b/tools/perf/util/unwind.c @@ -39,6 +39,15 @@ UNW_OBJ(dwarf_search_unwind_table) (unw_addr_space_t as,
#define dwarf_search_unwind_table UNW_OBJ(dwarf_search_unwind_table)
+extern int +UNW_OBJ(dwarf_find_debug_frame) (int found, unw_dyn_info_t *di_debug, + unw_word_t ip, + unw_word_t segbase, + const char *obj_name, unw_word_t start, + unw_word_t end); + +#define dwarf_find_debug_frame UNW_OBJ(dwarf_find_debug_frame) + #define DW_EH_PE_FORMAT_MASK 0x0f /* format of the encoded value */ #define DW_EH_PE_APPL_MASK 0x70 /* how the value is to be applied */
@@ -245,8 +254,9 @@ static int unwind_spec_ehframe(struct dso *dso, struct machine *machine, return 0; }
-static int read_unwind_spec(struct dso *dso, struct machine *machine, - u64 *table_data, u64 *segbase, u64 *fde_count) +static int read_unwind_spec_eh_frame(struct dso *dso, struct machine *machine, + u64 *table_data, u64 *segbase, + u64 *fde_count) { int ret = -EINVAL, fd; u64 offset; @@ -255,6 +265,7 @@ static int read_unwind_spec(struct dso *dso, struct machine *machine, if (fd < 0) return -EINVAL;
+ /* Check the .eh_frame section for unwinding info */ offset = elf_section_offset(fd, ".eh_frame_hdr"); close(fd);
@@ -263,10 +274,29 @@ static int read_unwind_spec(struct dso *dso, struct machine *machine, table_data, segbase, fde_count);
- /* TODO .debug_frame check if eh_frame_hdr fails */ return ret; }
+#ifndef NO_LIBUNWIND_DEBUG_FRAME +static int read_unwind_spec_debug_frame(struct dso *dso, + struct machine *machine, u64 *offset) +{ + int fd = dso__data_fd(dso, machine); + + if (fd < 0) + return -EINVAL; + + /* Check the .debug_frame section for unwinding info */ + *offset = elf_section_offset(fd, ".debug_frame"); + close(fd); + + if (*offset) + return 0; + + return -EINVAL; +} +#endif + static struct map *find_map(unw_word_t ip, struct unwind_info *ui) { struct addr_location al; @@ -291,20 +321,33 @@ find_proc_info(unw_addr_space_t as, unw_word_t ip, unw_proc_info_t *pi,
pr_debug("unwind: find_proc_info dso %s\n", map->dso->name);
- if (read_unwind_spec(map->dso, ui->machine, - &table_data, &segbase, &fde_count)) - return -EINVAL; + /* Check the .eh_frame section for unwinding info */ + if (!read_unwind_spec_eh_frame(map->dso, ui->machine, + &table_data, &segbase, &fde_count)) { + memset(&di, 0, sizeof(di)); + di.format = UNW_INFO_FORMAT_REMOTE_TABLE; + di.start_ip = map->start; + di.end_ip = map->end; + di.u.rti.segbase = map->start + segbase; + di.u.rti.table_data = map->start + table_data; + di.u.rti.table_len = fde_count * sizeof(struct table_entry) + / sizeof(unw_word_t); + return dwarf_search_unwind_table(as, ip, &di, pi, + need_unwind_info, arg); + } + +#ifndef NO_LIBUNWIND_DEBUG_FRAME + /* Check the .debug_frame section for unwinding info */ + if (!read_unwind_spec_debug_frame(map->dso, ui->machine, &segbase)) { + memset(&di, 0, sizeof(di)); + dwarf_find_debug_frame(0, &di, ip, 0, map->dso->name, + map->start, map->end); + return dwarf_search_unwind_table(as, ip, &di, pi, + need_unwind_info, arg); + } +#endif
- memset(&di, 0, sizeof(di)); - di.format = UNW_INFO_FORMAT_REMOTE_TABLE; - di.start_ip = map->start; - di.end_ip = map->end; - di.u.rti.segbase = map->start + segbase; - di.u.rti.table_data = map->start + table_data; - di.u.rti.table_len = fde_count * sizeof(struct table_entry) - / sizeof(unw_word_t); - return dwarf_search_unwind_table(as, ip, &di, pi, - need_unwind_info, arg); + return -EINVAL; }
static int access_fpreg(unw_addr_space_t __maybe_unused as,
On Thu, Sep 26, 2013 at 01:36:38PM +0200, Jean Pihet wrote:
On ARM the debug info is not present in the .eh_frame sections but in .debug_frame instead, in dwarf format. Use libunwind to load and parse the debug info.
Dependencies: . if present, libunwind >= 1.1 is needed to prevent a segfault when parsing the dwarf info, . libunwind needs to be configured with --enable-debug-frame. Note: --enable-debug-frame is automatically selected on ARM.
Acked-by: Jiri Olsa jolsa@redhat.com
thanks, jirka
Hi,
On 26 September 2013 14:49, Jiri Olsa jolsa@redhat.com wrote:
On Thu, Sep 26, 2013 at 01:36:38PM +0200, Jean Pihet wrote:
On ARM the debug info is not present in the .eh_frame sections but in .debug_frame instead, in dwarf format. Use libunwind to load and parse the debug info.
Dependencies: . if present, libunwind >= 1.1 is needed to prevent a segfault when parsing the dwarf info, . libunwind needs to be configured with --enable-debug-frame. Note: --enable-debug-frame is automatically selected on ARM.
Acked-by: Jiri Olsa jolsa@redhat.com
thanks, jirka
Thanks for the ack!
Is it possible to get an ack from the perf core maintainers? Also, is the patch going in Will's tree?
Regards, Jean
linaro-kernel@lists.linaro.org
-
Arnaldo Carvalho de Melo -
Jean Pihet -
Jiri Olsa -
Peter Zijlstra -
Will Deacon