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 = &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}
80