1// Check that if LSan finds that SP doesn't point into thread stack (e.g.
2// if swapcontext is used), LSan will not hit the guard page.
3// RUN: %clang_lsan %s -o %t && %run %t
4#include <errno.h>
5#include <stdio.h>
6#include <stdlib.h>
7#include <string.h>
8#include <pthread.h>
9#include <ucontext.h>
10
11pthread_cond_t cond = PTHREAD_COND_INITIALIZER;
12pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER;
13int ctxfunc_started = 0;
14
15static void die(const char* msg, int err) {
16  if (err == 0)
17    err = errno;
18  fprintf(stderr, "%s: %s\n", msg, strerror(err));
19  exit(EXIT_FAILURE);
20}
21
22static void ctxfunc() {
23  pthread_mutex_lock(&mutex);
24  ctxfunc_started = 1;
25  pthread_cond_signal(&cond);
26  pthread_mutex_unlock(&mutex);
27  // Leave this context alive when the program exits.
28  for (;;);
29}
30
31static void* thread(void* arg) {
32  (void)arg;
33  ucontext_t ctx;
34  void* stack;
35
36  if (getcontext(&ctx) < 0)
37    die("getcontext", 0);
38  stack = malloc(1 << 10);
39  if (stack == NULL)
40    die("malloc", 0);
41  ctx.uc_stack.ss_sp = stack;
42  ctx.uc_stack.ss_size = 1 << 10;
43  makecontext(&ctx, ctxfunc, 0);
44  setcontext(&ctx);
45  die("setcontext", 0);
46  return NULL;
47}
48
49int main() {
50  pthread_t tid;
51  int i;
52
53  pthread_mutex_lock(&mutex);
54  i = pthread_create(&tid, NULL, thread, NULL);
55  if (i != 0)
56    die("pthread_create", i);
57  while (!ctxfunc_started) pthread_cond_wait(&cond, &mutex);
58  pthread_mutex_unlock(&mutex);
59  return 0;
60}
61