sewardj | 8eb8bab | 2015-07-21 14:44:28 +0000 | [diff] [blame] | 1 | /* Test of correct simulation for active stack. */ |
| 2 | |
| 3 | #include <assert.h> |
| 4 | #include <signal.h> |
| 5 | #include <stdio.h> |
| 6 | #include <ucontext.h> |
| 7 | |
| 8 | static char altstack_map[8096]; |
| 9 | static volatile stack_t *sp; |
| 10 | |
| 11 | static void sighandler(int sig) |
| 12 | { |
| 13 | /* Check that the alternate stack is active. */ |
| 14 | assert(sp->ss_sp == altstack_map); |
| 15 | assert(sp->ss_size == sizeof(altstack_map)); |
| 16 | assert(sp->ss_flags == SS_ONSTACK); |
| 17 | } |
| 18 | |
| 19 | int main(void) |
| 20 | { |
| 21 | stack_t mainstack; |
| 22 | stack_t altstack; |
| 23 | struct sigaction sa; |
| 24 | /* Obtain an address inside the stack using a dirty trick. */ |
| 25 | void *local = &sa; |
| 26 | |
| 27 | /* Get an address for stack definition. */ |
| 28 | if (getustack((stack_t**)&sp)) { |
| 29 | perror("getustack"); |
| 30 | return 1; |
| 31 | } |
| 32 | |
| 33 | /* Check the current stack. */ |
| 34 | assert(sp->ss_sp <= local); |
| 35 | assert(local < (void*)((char*)sp->ss_sp + sp->ss_size)); |
| 36 | assert(sp->ss_flags == 0); |
| 37 | |
| 38 | /* Backup the current stack. */ |
| 39 | mainstack = *sp; |
| 40 | |
| 41 | /* Setup a signal handler. */ |
| 42 | sa.sa_handler = sighandler; |
| 43 | sa.sa_flags = SA_ONSTACK; |
| 44 | if (sigfillset(&sa.sa_mask)) { |
| 45 | perror("sigfillset"); |
| 46 | return 1; |
| 47 | } |
| 48 | if (sigaction(SIGUSR1, &sa, NULL)) { |
| 49 | perror("sigaction"); |
| 50 | return 1; |
| 51 | } |
| 52 | |
| 53 | /* Setup an alternate stack. */ |
| 54 | altstack.ss_sp = altstack_map; |
| 55 | altstack.ss_size = sizeof(altstack_map); |
| 56 | altstack.ss_flags = 0; |
| 57 | if (sigaltstack(&altstack, NULL)) { |
| 58 | perror("sigaltstack"); |
| 59 | return 1; |
| 60 | } |
| 61 | |
| 62 | /* Raise a signal. */ |
| 63 | raise(SIGUSR1); |
| 64 | |
| 65 | /* Check the current stack. */ |
| 66 | assert(mainstack.ss_sp == sp->ss_sp); |
| 67 | assert(mainstack.ss_size == sp->ss_size); |
| 68 | assert(mainstack.ss_flags == sp->ss_flags); |
| 69 | |
| 70 | return 0; |
| 71 | } |
| 72 | |