1// RUN: %clang_scudo %s -o %t
2// RUN: %run %t after 2>&1 | FileCheck %s
3// RUN: %run %t before 2>&1 | FileCheck %s
4
5// Test that we hit a guard page when writing past the end of a chunk
6// allocated by the Secondary allocator, or writing too far in front of it.
7
8#include <assert.h>
9#include <malloc.h>
10#include <signal.h>
11#include <stdlib.h>
12#include <string.h>
13#include <unistd.h>
14
15void handler(int signo, siginfo_t *info, void *uctx) {
16 if (info->si_code == SEGV_ACCERR) {
17 fprintf(stderr, format: "SCUDO SIGSEGV\n");
18 exit(status: 0);
19 }
20 exit(status: 1);
21}
22
23int main(int argc, char **argv) {
24 // The size must be large enough to be serviced by the secondary allocator.
25 long page_size = sysconf(_SC_PAGESIZE);
26 size_t size = (1U << 17) + page_size;
27 struct sigaction a;
28
29 assert(argc == 2);
30 memset(s: &a, c: 0, n: sizeof(a));
31 a.sa_sigaction = handler;
32 a.sa_flags = SA_SIGINFO;
33
34 char *p = (char *)malloc(size: size);
35 assert(p);
36 memset(s: p, c: 'A', n: size); // This should not trigger anything.
37 // Set up the SIGSEGV handler now, as the rest should trigger an AV.
38 sigaction(SIGSEGV, act: &a, NULL);
39 if (!strcmp(s1: argv[1], s2: "after")) {
40 for (int i = 0; i < page_size; i++)
41 p[size + i] = 'A';
42 }
43 if (!strcmp(s1: argv[1], s2: "before")) {
44 for (int i = 1; i < page_size; i++)
45 p[-i] = 'A';
46 }
47 free(ptr: p);
48
49 return 1; // A successful test means we shouldn't reach this.
50}
51
52// CHECK: SCUDO SIGSEGV
53

source code of compiler-rt/test/scudo/secondary.c