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