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(thread), (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(map) - sp;
37 map__put(map);
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
53int test__arch_unwind_sample(struct perf_sample *sample,
54 struct thread *thread)
55{
56 struct regs_dump *regs = perf_sample__user_regs(sample);
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}
80

source code of linux/tools/perf/arch/x86/tests/dwarf-unwind.c