ASan doesn't unpoison stack of subprocesses that share the same memory

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ASan doesn't unpoison stack of subprocesses that share the same memory

[GoogleCodeExporter]

or 3) instrumenting all noreturn calls with __tsan_unpoison_stack or some such. 
I'll give it a try. 

(and thanks for the repro)

Original comment by [email protected] on 8 Feb 2012 at 3:42

[GoogleCodeExporter]

shorter repro:

#include <sched.h>                                                              


#include <stdio.h>                                                              


#include <sys/syscall.h>                                                        


#include <sys/types.h>                                                          


#include <sys/wait.h>                                                           


#include <unistd.h>                                                             



int Child(void *arg) {                                                          


  char x[32] = {0};                                                                                                                                                                                 
  fprintf(stderr, "Child:  %p\n", x);                                                                                                                                                               
  volatile char *ch = x + 32;                                                                                                                                                                       
  _exit(1);                                                                                                                                                                                         
}                                                                               



int main(int argc, char **argv) {                                               


  const int kStackSize = 1 << 20;                                                                                                                                                                   
  char child_stack[kStackSize + 1];                                                                                                                                                                 
  char *sp = child_stack + kStackSize;  // Stack grows down.                                                                                                                                        
  fprintf(stderr, "Parent: %p\n", sp);                                                                                                                                                              
  pid_t clone_pid = clone(Child, sp, CLONE_FILES | CLONE_VM, NULL, 0, 0, 0);                                                                                                                        
  waitpid(clone_pid, NULL, 0);                                                                                                                                                                      
  for (int i = 0; i < kStackSize; i++)                                                                                                                                                              
    child_stack[i] = i;                                                                                                                                                                             
  return child_stack[argc - 1];                                                                                                                                                                     
}                                      

Original comment by [email protected] on 8 Feb 2012 at 6:45

[GoogleCodeExporter]

This particular test is fixed by r150101 / r150102.
Will see if it fixes more complicated cases. 

Original comment by [email protected] on 8 Feb 2012 at 9:41

• Changed state: Fixed