1 // RUN: %clang_safestack -fno-stack-protector -D_FORTIFY_SOURCE=0 -g %s -o %t.nossp
2 // RUN: %run %t.nossp 2>&1 | FileCheck --check-prefix=NOSSP %s
3
4 // RUN: %clang_safestack -fstack-protector-all -D_FORTIFY_SOURCE=0 -g %s -o %t.ssp
5 // RUN: not --crash %run %t.ssp 2>&1 | FileCheck -check-prefix=SSP %s
6
7 // Test stack canaries on the unsafe stack.
8
9 // REQUIRES: stable-runtime
10
11 #include <assert.h>
12 #include <stdio.h>
13 #include <string.h>
14
f(unsigned * y)15 __attribute__((noinline)) void f(unsigned *y) {
16 char x;
17 char *volatile p = &x;
18 char *volatile q = (char *)y;
19 assert(p < q);
20 assert(q - p < 1024); // sanity
21 // This has technically undefined behavior, but we know the actual layout of
22 // the unsafe stack and this should not touch anything important.
23 memset(&x, 0xab, q - p + sizeof(*y));
24 }
25
main(int argc,char ** argv)26 int main(int argc, char **argv)
27 {
28 unsigned y;
29 // NOSSP: main 1
30 // SSP: main 1
31 fprintf(stderr, "main 1\n");
32 f(&y);
33 // NOSSP: main 2
34 // SSP-NOT: main 2
35 fprintf(stderr, "main 2\n");
36 return 0;
37 }
38