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 }
80