LXR linux/tools/perf/arch/x86/tests/dwarf-unwind.c

   1// SPDX-License-Identifier: GPL-2.0
   2#include <string.h>
   3#include "perf_regs.h"
   4#include "thread.h"
   5#include "map.h"
   6#include "maps.h"
   7#include "event.h"
   8#include "debug.h"
   9#include "tests/tests.h"
  10
  11#define STACK_SIZE 8192
  12
  13static int sample_ustack(struct perf_sample *sample,
  14                         struct thread *thread, u64 *regs)
  15{
  16        struct stack_dump *stack = &sample->user_stack;
  17        struct map *map;
  18        unsigned long sp;
  19        u64 stack_size, *buf;
  20
  21        buf = malloc(STACK_SIZE);
  22        if (!buf) {
  23                pr_debug("failed to allocate sample uregs data\n");
  24                return -1;
  25        }
  26
  27        sp = (unsigned long) regs[PERF_REG_X86_SP];
  28
  29        map = maps__find(thread->maps, (u64)sp);
  30        if (!map) {
  31                pr_debug("failed to get stack map\n");
  32                free(buf);
  33                return -1;
  34        }
  35
  36        stack_size = map->end - sp;
  37        stack_size = stack_size > STACK_SIZE ? STACK_SIZE : stack_size;
  38
  39        memcpy(buf, (void *) sp, stack_size);
  40#ifdef MEMORY_SANITIZER
  41        /*
  42         * Copying the stack may copy msan poison, avoid false positives in the
  43         * unwinder by removing the poison here.
  44         */
  45        __msan_unpoison(buf, stack_size);
  46#endif
  47        stack->data = (char *) buf;
  48        stack->size = stack_size;
  49        return 0;
  50}
  51
  52int test__arch_unwind_sample(struct perf_sample *sample,
  53                             struct thread *thread)
  54{
  55        struct regs_dump *regs = &sample->user_regs;
  56        u64 *buf;
  57
  58        buf = malloc(sizeof(u64) * PERF_REGS_MAX);
  59        if (!buf) {
  60                pr_debug("failed to allocate sample uregs data\n");
  61                return -1;
  62        }
  63
  64#ifdef MEMORY_SANITIZER
  65        /*
  66         * Assignments to buf in the assembly function perf_regs_load aren't
  67         * seen by memory sanitizer. Zero the memory to convince memory
  68         * sanitizer the memory is initialized.
  69         */
  70        memset(buf, 0, sizeof(u64) * PERF_REGS_MAX);
  71#endif
  72        perf_regs_load(buf);
  73        regs->abi  = PERF_SAMPLE_REGS_ABI;
  74        regs->regs = buf;
  75        regs->mask = PERF_REGS_MASK;
  76
  77        return sample_ustack(sample, thread, buf);
  78}
  79