1 #include <stdio.h>
2 #include <stdlib.h>
3 #include <ucontext.h>
4 #include "tests/sys_mman.h"
5
6 #include "valgrind.h"
7
8 #define STACK_SIZE (10 * 4096)
9
10 // This test is checking the libc context calls (setcontext, etc.) and
11 // checks that Valgrind notices their stack changes properly.
12
13 typedef struct ucontext mycontext;
14
15 mycontext ctx1, ctx2, oldc;
16 int count;
17
hello(mycontext * newc)18 void hello(mycontext *newc)
19 {
20 printf("hello, world: %d\n", count);
21 if (count++ == 2)
22 newc = &oldc;
23 setcontext(newc);
24 }
25
init_context(mycontext * uc)26 int init_context(mycontext *uc)
27 {
28 void *stack;
29 int ret;
30
31 if (getcontext(uc) == -1) {
32 //perror("getcontext");
33 printf("getcontext() doesn't seem to work\n");
34 exit(1);
35 }
36
37 stack = (void *)mmap(0, STACK_SIZE, PROT_READ|PROT_WRITE|PROT_EXEC,
38 MAP_ANONYMOUS|MAP_PRIVATE, -1, 0);
39
40 if (stack == (void*)-1) {
41 perror("mmap");
42 exit(1);
43 }
44
45 ret = VALGRIND_STACK_REGISTER(stack, stack + STACK_SIZE);
46
47 uc->uc_link = NULL;
48 uc->uc_stack.ss_sp = stack;
49 uc->uc_stack.ss_size = STACK_SIZE;
50 uc->uc_stack.ss_flags = 0;
51
52 return ret;
53 }
54
main(int argc,char ** argv)55 int main(int argc, char **argv)
56 {
57 int c1 = init_context(&ctx1);
58 int c2 = init_context(&ctx2);
59
60 makecontext(&ctx1, (void (*)()) hello, 1, &ctx2);
61 makecontext(&ctx2, (void (*)()) hello, 1, &ctx1);
62
63 swapcontext(&oldc, &ctx1);
64
65 VALGRIND_STACK_DEREGISTER(c1);
66 //free(ctx1.uc_stack.ss_sp);
67 VALGRIND_STACK_DEREGISTER(c2);
68 //free(ctx2.uc_stack.ss_sp);
69
70 return 0;
71 }
72