gcc/testsuite/c-c++-common/asan/swapcontext-test-1.c

   1 /* Check that ASan plays well with easy cases of makecontext/swapcontext. */
   2
   3 /* { dg-do run { target swapcontext } } */
   4
   5 #include <stdio.h>
   6 #include <ucontext.h>
   7 #include <unistd.h>
   8
   9 ucontext_t orig_context;
  10 ucontext_t child_context;
  11
  12 void Child(int mode) {
  13   char x[32] = {0};  /* Stack gets poisoned. */
  14   printf("Child: %p\n", x);
  15   /* (a) Do nothing, just return to parent function.
  16      (b) Jump into the original function. Stack remains poisoned unless we do
  17          something. */
  18   if (mode == 1) {
  19     if (swapcontext(&child_context, &orig_context) < 0) {
  20       perror("swapcontext");
  21       _exit(0);
  22     }
  23   }
  24 }
  25
  26 int Run(int arg, int mode) {
  27   int i;
  28   const int kStackSize = 1 << 20;
  29   char child_stack[kStackSize + 1];
  30   printf("Child stack: %p\n", child_stack);
  31   /* Setup child context. */
  32   getcontext(&child_context);
  33   child_context.uc_stack.ss_sp = child_stack;
  34   child_context.uc_stack.ss_size = kStackSize / 2;
  35   if (mode == 0) {
  36     child_context.uc_link = &orig_context;
  37   }
  38   makecontext(&child_context, (void (*)())Child, 1, mode);
  39   if (swapcontext(&orig_context, &child_context) < 0) {
  40     perror("swapcontext");
  41     return 0;
  42   }
  43   /* Touch childs's stack to make sure it's unpoisoned. */
  44   for (i = 0; i < kStackSize; i++) {
  45     child_stack[i] = i;
  46   }
  47   return child_stack[arg];
  48 }
  49
  50 volatile int zero = 0;
  51
  52 int main(int argc, char **argv) {
  53   int ret = 0;
  54   ret += Run(zero, 0);
  55   printf("Test1 passed\n");
  56   ret += Run(zero, 1);
  57   printf("Test2 passed\n");
  58   return ret;
  59 }
  60
  61 /* { dg-output "WARNING: ASan doesn't fully support makecontext/swapcontext.*" } */
  62 /* { dg-output "Test1 passed.*" } */
  63 /* { dg-output "Test2 passed.*" } */