From 7495f3742dda97612a77d92fa62f85cb7591ab14 Mon Sep 17 00:00:00 2001 From: Will Deacon Date: Thu, 26 Sep 2013 12:36:36 +0100 Subject: ARM: perf: wire up perf_regs and unwind support for ARM This patch hooks in the perf_regs and libunwind code for ARM. Cc: Jean Pihet Signed-off-by: Will Deacon --- 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 (limited to 'tools/perf') diff --git a/tools/perf/arch/arm/Makefile b/tools/perf/arch/arm/Makefile index 15130b50dfe3..fe9b61e322a5 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 000000000000..2a1cfde66b69 --- /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 +#include "../../util/types.h" +#include + +#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 000000000000..da3dc950550c --- /dev/null +++ b/tools/perf/arch/arm/util/unwind.c @@ -0,0 +1,48 @@ + +#include +#include +#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 5f6f9b3271bb..4796ce54e653 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 ($(NO_PERF_REGS),0) CFLAGS += -DHAVE_PERF_REGS @@ -208,8 +212,7 @@ ifeq ($(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 -- cgit v1.2.3 From 405ffbd4988118c56ff127792ebddae77d2c7a43 Mon Sep 17 00:00:00 2001 From: Jean Pihet Date: Thu, 26 Sep 2013 12:36:37 +0100 Subject: perf tools: Check libunwind for availability of dwarf parsing feature 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 Signed-off-by: Jean Pihet Signed-off-by: Will Deacon --- tools/perf/config/Makefile | 6 +++++- tools/perf/config/feature-tests.mak | 21 ++++++++++++++++++++- 2 files changed, 25 insertions(+), 2 deletions(-) (limited to 'tools/perf') diff --git a/tools/perf/config/Makefile b/tools/perf/config/Makefile index 4796ce54e653..75b93d7f7860 100644 --- a/tools/perf/config/Makefile +++ b/tools/perf/config/Makefile @@ -226,9 +226,13 @@ 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 d5a8dd44945f..40b21c0bc10a 100644 --- a/tools/perf/config/feature-tests.mak +++ b/tools/perf/config/feature-tests.mak @@ -185,7 +185,6 @@ 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) @@ -197,6 +196,26 @@ int main(void) return 0; } endef + +define SOURCE_LIBUNWIND_DEBUG_FRAME +#include +#include + +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 -- cgit v1.2.3 From ab255e72204fc5127f0adf40ba103d9335fefa30 Mon Sep 17 00:00:00 2001 From: Jean Pihet Date: Thu, 26 Sep 2013 12:36:38 +0100 Subject: perf: parse the .debug_frame section in case .eh_frame is not present 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 Signed-off-by: Jean Pihet Signed-off-by: Will Deacon --- tools/perf/util/unwind.c | 75 +++++++++++++++++++++++++++++++++++++----------- 1 file changed, 59 insertions(+), 16 deletions(-) (limited to 'tools/perf') diff --git a/tools/perf/util/unwind.c b/tools/perf/util/unwind.c index 2f891f7e70bf..5390d0b8862a 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, -- cgit v1.2.3