1 // Check that ASan plays well with easy cases of makecontext/swapcontext.
2
3 // RUN: %clangxx_asan -O0 %s -o %t && %run %t 2>&1 | FileCheck %s
4 // RUN: %clangxx_asan -O1 %s -o %t && %run %t 2>&1 | FileCheck %s
5 // RUN: %clangxx_asan -O2 %s -o %t && %run %t 2>&1 | FileCheck %s
6 // RUN: %clangxx_asan -O3 %s -o %t && %run %t 2>&1 | FileCheck %s
7 //
8 // This test is too sublte to try on non-x86 arch for now.
9 // REQUIRES: x86_64-supported-target,i386-supported-target
10
11 #include <stdio.h>
12 #include <ucontext.h>
13 #include <unistd.h>
14
15 ucontext_t orig_context;
16 ucontext_t child_context;
17
18 const int kStackSize = 1 << 20;
19
20 __attribute__((noinline))
Throw()21 void Throw() {
22 throw 1;
23 }
24
25 __attribute__((noinline))
ThrowAndCatch()26 void ThrowAndCatch() {
27 try {
28 Throw();
29 } catch(int a) {
30 printf("ThrowAndCatch: %d\n", a);
31 }
32 }
33
Child(int mode)34 void Child(int mode) {
35 char x[32] = {0}; // Stack gets poisoned.
36 printf("Child: %p\n", x);
37 ThrowAndCatch(); // Simulate __asan_handle_no_return().
38 // (a) Do nothing, just return to parent function.
39 // (b) Jump into the original function. Stack remains poisoned unless we do
40 // something.
41 if (mode == 1) {
42 if (swapcontext(&child_context, &orig_context) < 0) {
43 perror("swapcontext");
44 _exit(0);
45 }
46 }
47 }
48
Run(int arg,int mode,char * child_stack)49 int Run(int arg, int mode, char *child_stack) {
50 printf("Child stack: %p\n", child_stack);
51 // Setup child context.
52 getcontext(&child_context);
53 child_context.uc_stack.ss_sp = child_stack;
54 child_context.uc_stack.ss_size = kStackSize / 2;
55 if (mode == 0) {
56 child_context.uc_link = &orig_context;
57 }
58 makecontext(&child_context, (void (*)())Child, 1, mode);
59 if (swapcontext(&orig_context, &child_context) < 0) {
60 perror("swapcontext");
61 return 0;
62 }
63 // Touch childs's stack to make sure it's unpoisoned.
64 for (int i = 0; i < kStackSize; i++) {
65 child_stack[i] = i;
66 }
67 return child_stack[arg];
68 }
69
main(int argc,char ** argv)70 int main(int argc, char **argv) {
71 char stack[kStackSize + 1];
72 // CHECK: WARNING: ASan doesn't fully support makecontext/swapcontext
73 int ret = 0;
74 ret += Run(argc - 1, 0, stack);
75 printf("Test1 passed\n");
76 // CHECK: Test1 passed
77 ret += Run(argc - 1, 1, stack);
78 printf("Test2 passed\n");
79 // CHECK: Test2 passed
80 char *heap = new char[kStackSize + 1];
81 ret += Run(argc - 1, 0, heap);
82 printf("Test3 passed\n");
83 // CHECK: Test3 passed
84 ret += Run(argc - 1, 1, heap);
85 printf("Test4 passed\n");
86 // CHECK: Test4 passed
87
88 delete [] heap;
89 return ret;
90 }
91