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1// RUN: %clang_safestack %s -pthread -o %t2// RUN: %run %t 03// RUN: not --crash %run %t 14 5// Test unsafe stack deallocation. Unsafe stacks are not deallocated immediately6// at thread exit. They are deallocated by following exiting threads.7 8#include <stdlib.h>9#include <string.h>10#include <pthread.h>11 12enum { kBufferSize = (1 << 15) };13 14void *start(void *ptr)15{16 char buffer[kBufferSize];17 return buffer;18}19 20extern unsigned sleep(unsigned seconds);21 22int main(int argc, char **argv)23{24 int arg = atoi(argv[1]);25 26 pthread_t t1, t2;27 char *t1_buffer = NULL;28 29 if (pthread_create(&t1, NULL, start, NULL))30 abort();31 if (pthread_join(t1, (void **)&t1_buffer))32 abort();33 34 // Stack has not yet been deallocated35 memset(t1_buffer, 0, kBufferSize);36 37 if (arg == 0)38 return 0;39 40 for (int i = 0; i < 3; i++) {41 if (pthread_create(&t2, NULL, start, NULL))42 abort();43 // Second thread destructor cleans up the first thread's stack.44 if (pthread_join(t2, NULL))45 abort();46 47 // Should segfault here48 memset(t1_buffer, 0, kBufferSize);49 50 // PR39001: Re-try in the rare case that pthread_join() returns before the51 // thread finishes exiting in the kernel--hence the tgkill() check for t152 // returns that it's alive despite pthread_join() returning.53 sleep(1);54 }55 return 0;56}57