diff options
Diffstat (limited to '')
| -rw-r--r-- | tools/perf/util/unwind-libunwind-local.c | 115 |
1 files changed, 82 insertions, 33 deletions
diff --git a/tools/perf/util/unwind-libunwind-local.c b/tools/perf/util/unwind-libunwind-local.c index 71a353349181..81b6bd6e1536 100644 --- a/tools/perf/util/unwind-libunwind-local.c +++ b/tools/perf/util/unwind-libunwind-local.c @@ -96,6 +96,7 @@ struct unwind_info { struct perf_sample *sample; struct machine *machine; struct thread *thread; + bool best_effort; }; #define dw_read(ptr, type, end) ({ \ @@ -168,29 +169,63 @@ static int __dw_read_encoded_value(u8 **p, u8 *end, u64 *val, __v; \ }) -static u64 elf_section_offset(int fd, const char *name) +static int elf_section_address_and_offset(int fd, const char *name, u64 *address, u64 *offset) { Elf *elf; GElf_Ehdr ehdr; GElf_Shdr shdr; - u64 offset = 0; + int ret = -1; elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL); if (elf == NULL) + return -1; + + if (gelf_getehdr(elf, &ehdr) == NULL) + goto out_err; + + if (!elf_section_by_name(elf, &ehdr, &shdr, name, NULL)) + goto out_err; + + *address = shdr.sh_addr; + *offset = shdr.sh_offset; + ret = 0; +out_err: + elf_end(elf); + return ret; +} + +#ifndef NO_LIBUNWIND_DEBUG_FRAME +static u64 elf_section_offset(int fd, const char *name) +{ + u64 address, offset = 0; + + if (elf_section_address_and_offset(fd, name, &address, &offset)) return 0; - do { - if (gelf_getehdr(elf, &ehdr) == NULL) - break; + return offset; +} +#endif - if (!elf_section_by_name(elf, &ehdr, &shdr, name, NULL)) - break; +static u64 elf_base_address(int fd) +{ + Elf *elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL); + GElf_Phdr phdr; + u64 retval = 0; + size_t i, phdrnum = 0; - offset = shdr.sh_offset; - } while (0); + if (elf == NULL) + return 0; + (void)elf_getphdrnum(elf, &phdrnum); + /* PT_LOAD segments are sorted by p_vaddr, so the first has the minimum p_vaddr. */ + for (i = 0; i < phdrnum; i++) { + if (gelf_getphdr(elf, i, &phdr) && phdr.p_type == PT_LOAD) { + retval = phdr.p_vaddr & -getpagesize(); + break; + } + } elf_end(elf); - return offset; + return retval; } #ifndef NO_LIBUNWIND_DEBUG_FRAME @@ -247,8 +282,7 @@ struct eh_frame_hdr { } __packed; static int unwind_spec_ehframe(struct dso *dso, struct machine *machine, - u64 offset, u64 *table_data, u64 *segbase, - u64 *fde_count) + u64 offset, u64 *table_data_offset, u64 *fde_count) { struct eh_frame_hdr hdr; u8 *enc = (u8 *) &hdr.enc; @@ -264,35 +298,47 @@ static int unwind_spec_ehframe(struct dso *dso, struct machine *machine, dw_read_encoded_value(enc, end, hdr.eh_frame_ptr_enc); *fde_count = dw_read_encoded_value(enc, end, hdr.fde_count_enc); - *segbase = offset; - *table_data = (enc - (u8 *) &hdr) + offset; + *table_data_offset = enc - (u8 *) &hdr; return 0; } -static int read_unwind_spec_eh_frame(struct dso *dso, struct machine *machine, +static int read_unwind_spec_eh_frame(struct dso *dso, struct unwind_info *ui, u64 *table_data, u64 *segbase, u64 *fde_count) { - int ret = -EINVAL, fd; - u64 offset = dso->data.eh_frame_hdr_offset; + struct map *map; + u64 base_addr = UINT64_MAX; + int ret, fd; - if (offset == 0) { - fd = dso__data_get_fd(dso, machine); + if (dso->data.eh_frame_hdr_offset == 0) { + fd = dso__data_get_fd(dso, ui->machine); if (fd < 0) return -EINVAL; /* Check the .eh_frame section for unwinding info */ - offset = elf_section_offset(fd, ".eh_frame_hdr"); - dso->data.eh_frame_hdr_offset = offset; + ret = elf_section_address_and_offset(fd, ".eh_frame_hdr", + &dso->data.eh_frame_hdr_addr, + &dso->data.eh_frame_hdr_offset); + dso->data.elf_base_addr = elf_base_address(fd); dso__data_put_fd(dso); + if (ret || dso->data.eh_frame_hdr_offset == 0) + return -EINVAL; } - if (offset) - ret = unwind_spec_ehframe(dso, machine, offset, - table_data, segbase, - fde_count); - - return ret; + maps__for_each_entry(ui->thread->maps, map) { + if (map->dso == dso && map->start < base_addr) + base_addr = map->start; + } + base_addr -= dso->data.elf_base_addr; + /* Address of .eh_frame_hdr */ + *segbase = base_addr + dso->data.eh_frame_hdr_addr; + ret = unwind_spec_ehframe(dso, ui->machine, dso->data.eh_frame_hdr_offset, + table_data, fde_count); + if (ret) + return ret; + /* binary_search_table offset plus .eh_frame_hdr address */ + *table_data += *segbase; + return 0; } #ifndef NO_LIBUNWIND_DEBUG_FRAME @@ -387,14 +433,14 @@ 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); /* Check the .eh_frame section for unwinding info */ - if (!read_unwind_spec_eh_frame(map->dso, ui->machine, + if (!read_unwind_spec_eh_frame(map->dso, ui, &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 - map->pgoff; - di.u.rti.table_data = map->start + table_data - map->pgoff; + di.u.rti.segbase = segbase; + di.u.rti.table_data = table_data; di.u.rti.table_len = fde_count * sizeof(struct table_entry) / sizeof(unw_word_t); ret = dwarf_search_unwind_table(as, ip, &di, pi, @@ -553,7 +599,8 @@ static int access_reg(unw_addr_space_t __maybe_unused as, ret = perf_reg_value(&val, &ui->sample->user_regs, id); if (ret) { - pr_err("unwind: can't read reg %d\n", regnum); + if (!ui->best_effort) + pr_err("unwind: can't read reg %d\n", regnum); return ret; } @@ -666,7 +713,7 @@ static int get_entries(struct unwind_info *ui, unwind_entry_cb_t cb, return -1; ret = unw_init_remote(&c, addr_space, ui); - if (ret) + if (ret && !ui->best_effort) display_error(ret); while (!ret && (unw_step(&c) > 0) && i < max_stack) { @@ -704,12 +751,14 @@ static int get_entries(struct unwind_info *ui, unwind_entry_cb_t cb, static int _unwind__get_entries(unwind_entry_cb_t cb, void *arg, struct thread *thread, - struct perf_sample *data, int max_stack) + struct perf_sample *data, int max_stack, + bool best_effort) { struct unwind_info ui = { .sample = data, .thread = thread, .machine = thread->maps->machine, + .best_effort = best_effort }; if (!data->user_regs.regs) |