diff options
| -rw-r--r-- | tools/perf/Makefile.perf | 11 | ||||
| -rw-r--r-- | tools/perf/arch/x86/Makefile | 3 | ||||
| -rw-r--r-- | tools/perf/arch/x86/util/unwind-libdw.c | 51 | ||||
| -rw-r--r-- | tools/perf/config/Makefile | 1 | ||||
| -rw-r--r-- | tools/perf/util/unwind-libdw.c | 210 | ||||
| -rw-r--r-- | tools/perf/util/unwind-libdw.h | 21 |
6 files changed, 297 insertions, 0 deletions
diff --git a/tools/perf/Makefile.perf b/tools/perf/Makefile.perf index bde91f8..2dff0b8 100644 --- a/tools/perf/Makefile.perf +++ b/tools/perf/Makefile.perf @@ -57,6 +57,12 @@ include config/utilities.mak # Define NO_LIBAUDIT if you do not want libaudit support # # Define NO_LIBBIONIC if you do not want bionic support +# +# Define NO_LIBDW_DWARF_UNWIND if you do not want libdw support +# for dwarf backtrace post unwind. + +# temporarily disabled +NO_LIBDW_DWARF_UNWIND := 1 ifeq ($(srctree),) srctree := $(patsubst %/,%,$(dir $(shell pwd))) @@ -478,6 +484,11 @@ ifndef NO_DWARF endif # NO_DWARF endif # NO_LIBELF +ifndef NO_LIBDW_DWARF_UNWIND + LIB_OBJS += $(OUTPUT)util/unwind-libdw.o + LIB_H += util/unwind-libdw.h +endif + ifndef NO_LIBUNWIND LIB_OBJS += $(OUTPUT)util/unwind-libunwind.o endif diff --git a/tools/perf/arch/x86/Makefile b/tools/perf/arch/x86/Makefile index 4fa9be9..37c4652 100644 --- a/tools/perf/arch/x86/Makefile +++ b/tools/perf/arch/x86/Makefile @@ -7,6 +7,9 @@ LIB_OBJS += $(OUTPUT)arch/$(ARCH)/util/unwind-libunwind.o LIB_OBJS += $(OUTPUT)arch/$(ARCH)/tests/regs_load.o LIB_OBJS += $(OUTPUT)arch/$(ARCH)/tests/dwarf-unwind.o endif +ifndef NO_LIBDW_DWARF_UNWIND +LIB_OBJS += $(OUTPUT)arch/$(ARCH)/util/unwind-libdw.o +endif LIB_OBJS += $(OUTPUT)arch/$(ARCH)/util/header.o LIB_OBJS += $(OUTPUT)arch/$(ARCH)/util/tsc.o LIB_H += arch/$(ARCH)/util/tsc.h diff --git a/tools/perf/arch/x86/util/unwind-libdw.c b/tools/perf/arch/x86/util/unwind-libdw.c new file mode 100644 index 0000000..c4b7217 --- /dev/null +++ b/tools/perf/arch/x86/util/unwind-libdw.c @@ -0,0 +1,51 @@ +#include <elfutils/libdwfl.h> +#include "../../util/unwind-libdw.h" +#include "../../util/perf_regs.h" + +bool libdw__arch_set_initial_registers(Dwfl_Thread *thread, void *arg) +{ + struct unwind_info *ui = arg; + struct regs_dump *user_regs = &ui->sample->user_regs; + Dwarf_Word dwarf_regs[17]; + unsigned nregs; + +#define REG(r) ({ \ + Dwarf_Word val = 0; \ + perf_reg_value(&val, user_regs, PERF_REG_X86_##r); \ + val; \ +}) + + if (user_regs->abi == PERF_SAMPLE_REGS_ABI_32) { + dwarf_regs[0] = REG(AX); + dwarf_regs[1] = REG(CX); + dwarf_regs[2] = REG(DX); + dwarf_regs[3] = REG(BX); + dwarf_regs[4] = REG(SP); + dwarf_regs[5] = REG(BP); + dwarf_regs[6] = REG(SI); + dwarf_regs[7] = REG(DI); + dwarf_regs[8] = REG(IP); + nregs = 9; + } else { + dwarf_regs[0] = REG(AX); + dwarf_regs[1] = REG(DX); + dwarf_regs[2] = REG(CX); + dwarf_regs[3] = REG(BX); + dwarf_regs[4] = REG(SI); + dwarf_regs[5] = REG(DI); + dwarf_regs[6] = REG(BP); + dwarf_regs[7] = REG(SP); + dwarf_regs[8] = REG(R8); + dwarf_regs[9] = REG(R9); + dwarf_regs[10] = REG(R10); + dwarf_regs[11] = REG(R11); + dwarf_regs[12] = REG(R12); + dwarf_regs[13] = REG(R13); + dwarf_regs[14] = REG(R14); + dwarf_regs[15] = REG(R15); + dwarf_regs[16] = REG(IP); + nregs = 17; + } + + return dwfl_thread_state_registers(thread, 0, nregs, dwarf_regs); +} diff --git a/tools/perf/config/Makefile b/tools/perf/config/Makefile index 074fa61..c040d86 100644 --- a/tools/perf/config/Makefile +++ b/tools/perf/config/Makefile @@ -261,6 +261,7 @@ ifdef NO_LIBELF NO_DWARF := 1 NO_DEMANGLE := 1 NO_LIBUNWIND := 1 + NO_LIBDW_DWARF_UNWIND := 1 else ifeq ($(feature-libelf), 0) ifeq ($(feature-glibc), 1) diff --git a/tools/perf/util/unwind-libdw.c b/tools/perf/util/unwind-libdw.c new file mode 100644 index 0000000..67db73e --- /dev/null +++ b/tools/perf/util/unwind-libdw.c @@ -0,0 +1,210 @@ +#include <linux/compiler.h> +#include <elfutils/libdw.h> +#include <elfutils/libdwfl.h> +#include <inttypes.h> +#include <errno.h> +#include "unwind.h" +#include "unwind-libdw.h" +#include "machine.h" +#include "thread.h" +#include "types.h" +#include "event.h" +#include "perf_regs.h" + +static char *debuginfo_path; + +static const Dwfl_Callbacks offline_callbacks = { + .find_debuginfo = dwfl_standard_find_debuginfo, + .debuginfo_path = &debuginfo_path, + .section_address = dwfl_offline_section_address, +}; + +static int __report_module(struct addr_location *al, u64 ip, + struct unwind_info *ui) +{ + Dwfl_Module *mod; + struct dso *dso = NULL; + + thread__find_addr_location(ui->thread, ui->machine, + PERF_RECORD_MISC_USER, + MAP__FUNCTION, ip, al); + + if (al->map) + dso = al->map->dso; + + if (!dso) + return 0; + + mod = dwfl_addrmodule(ui->dwfl, ip); + if (!mod) + mod = dwfl_report_elf(ui->dwfl, dso->short_name, + dso->long_name, -1, al->map->start, + false); + + return mod && dwfl_addrmodule(ui->dwfl, ip) == mod ? 0 : -1; +} + +static int report_module(u64 ip, struct unwind_info *ui) +{ + struct addr_location al; + + return __report_module(&al, ip, ui); +} + +static int entry(u64 ip, struct unwind_info *ui) + +{ + struct unwind_entry e; + struct addr_location al; + + if (__report_module(&al, ip, ui)) + return -1; + + e.ip = ip; + e.map = al.map; + e.sym = al.sym; + + pr_debug("unwind: %s:ip = 0x%" PRIx64 " (0x%" PRIx64 ")\n", + al.sym ? al.sym->name : "''", + ip, + al.map ? al.map->map_ip(al.map, ip) : (u64) 0); + + return ui->cb(&e, ui->arg); +} + +static pid_t next_thread(Dwfl *dwfl, void *arg, void **thread_argp) +{ + /* We want only single thread to be processed. */ + if (*thread_argp != NULL) + return 0; + + *thread_argp = arg; + return dwfl_pid(dwfl); +} + +static int access_dso_mem(struct unwind_info *ui, Dwarf_Addr addr, + Dwarf_Word *data) +{ + struct addr_location al; + ssize_t size; + + thread__find_addr_map(ui->thread, ui->machine, PERF_RECORD_MISC_USER, + MAP__FUNCTION, addr, &al); + if (!al.map) { + pr_debug("unwind: no map for %lx\n", (unsigned long)addr); + return -1; + } + + if (!al.map->dso) + return -1; + + size = dso__data_read_addr(al.map->dso, al.map, ui->machine, + addr, (u8 *) data, sizeof(*data)); + + return !(size == sizeof(*data)); +} + +static bool memory_read(Dwfl *dwfl __maybe_unused, Dwarf_Addr addr, Dwarf_Word *result, + void *arg) +{ + struct unwind_info *ui = arg; + struct stack_dump *stack = &ui->sample->user_stack; + u64 start, end; + int offset; + int ret; + + ret = perf_reg_value(&start, &ui->sample->user_regs, PERF_REG_SP); + if (ret) + return false; + + end = start + stack->size; + + /* Check overflow. */ + if (addr + sizeof(Dwarf_Word) < addr) + return false; + + if (addr < start || addr + sizeof(Dwarf_Word) > end) { + ret = access_dso_mem(ui, addr, result); + if (ret) { + pr_debug("unwind: access_mem 0x%" PRIx64 " not inside range" + " 0x%" PRIx64 "-0x%" PRIx64 "\n", + addr, start, end); + return false; + } + return true; + } + + offset = addr - start; + *result = *(Dwarf_Word *)&stack->data[offset]; + pr_debug("unwind: access_mem addr 0x%" PRIx64 ", val %lx, offset %d\n", + addr, (unsigned long)*result, offset); + return true; +} + +static const Dwfl_Thread_Callbacks callbacks = { + .next_thread = next_thread, + .memory_read = memory_read, + .set_initial_registers = libdw__arch_set_initial_registers, +}; + +static int +frame_callback(Dwfl_Frame *state, void *arg) +{ + struct unwind_info *ui = arg; + Dwarf_Addr pc; + + if (!dwfl_frame_pc(state, &pc, NULL)) { + pr_err("%s", dwfl_errmsg(-1)); + return DWARF_CB_ABORT; + } + + return entry(pc, ui) || !(--ui->max_stack) ? + DWARF_CB_ABORT : DWARF_CB_OK; +} + +int unwind__get_entries(unwind_entry_cb_t cb, void *arg, + struct machine *machine, struct thread *thread, + struct perf_sample *data, + int max_stack) +{ + struct unwind_info ui = { + .sample = data, + .thread = thread, + .machine = machine, + .cb = cb, + .arg = arg, + .max_stack = max_stack, + }; + Dwarf_Word ip; + int err = -EINVAL; + + if (!data->user_regs.regs) + return -EINVAL; + + ui.dwfl = dwfl_begin(&offline_callbacks); + if (!ui.dwfl) + goto out; + + err = perf_reg_value(&ip, &data->user_regs, PERF_REG_IP); + if (err) + goto out; + + err = report_module(ip, &ui); + if (err) + goto out; + + if (!dwfl_attach_state(ui.dwfl, EM_NONE, thread->tid, &callbacks, &ui)) + goto out; + + err = dwfl_getthread_frames(ui.dwfl, thread->tid, frame_callback, &ui); + + if (err && !ui.max_stack) + err = 0; + + out: + if (err) + pr_debug("unwind: failed with '%s'\n", dwfl_errmsg(-1)); + + dwfl_end(ui.dwfl); + return 0; +} diff --git a/tools/perf/util/unwind-libdw.h b/tools/perf/util/unwind-libdw.h new file mode 100644 index 0000000..417a142 --- /dev/null +++ b/tools/perf/util/unwind-libdw.h @@ -0,0 +1,21 @@ +#ifndef __PERF_UNWIND_LIBDW_H +#define __PERF_UNWIND_LIBDW_H + +#include <elfutils/libdwfl.h> +#include "event.h" +#include "thread.h" +#include "unwind.h" + +bool libdw__arch_set_initial_registers(Dwfl_Thread *thread, void *arg); + +struct unwind_info { + Dwfl *dwfl; + struct perf_sample *sample; + struct machine *machine; + struct thread *thread; + unwind_entry_cb_t cb; + void *arg; + int max_stack; +}; + +#endif /* __PERF_UNWIND_LIBDW_H */ |
