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Original file line number | Diff line number | Diff line change |
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#include <sys/types.h> | ||
#include <sys/syscall.h> | ||
#include <unistd.h> | ||
#include <signal.h> | ||
#include <stdlib.h> | ||
#include <string.h> | ||
#include <stdio.h> | ||
#include <assert.h> | ||
#include <errno.h> | ||
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#ifndef SA_RESTORER | ||
#define SA_RESTORER 0x04000000 | ||
#endif | ||
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struct kernel_sigaction { | ||
unsigned long sa__; | ||
unsigned long flags; | ||
unsigned long restorer; | ||
unsigned long masks; | ||
}; | ||
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static int rt_sigreturn(void* regs) | ||
{ | ||
return (int)syscall(SYS_rt_sigreturn, regs); | ||
} | ||
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static int rt_sigaction(int signum, const struct kernel_sigaction* new, struct kernel_sigaction* old) | ||
{ | ||
unsigned long r = (unsigned long)syscall(SYS_rt_sigaction, signum, new, old, 8); | ||
if ( r >= ~0xfffUL) { | ||
return (int)r; | ||
} else { | ||
return (int)r; | ||
} | ||
} | ||
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static volatile int quit = 0; | ||
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static void handler(int sig, siginfo_t *info, void *ucontext) | ||
{ | ||
printf("[OK] received signal %u\n", sig); | ||
quit = 1; | ||
} | ||
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extern int __restore_rt(void); | ||
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int main(int argc, char* argv[]) | ||
{ | ||
int ret; | ||
struct kernel_sigaction old, new; | ||
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memset(&old, 0, sizeof(old)); | ||
memset(&new, 0, sizeof(new)); | ||
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new.sa__ = (unsigned long)handler; | ||
new.flags = SA_RESTART | SA_RESTORER; | ||
new.restorer = (unsigned long)rt_sigreturn; | ||
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ret = rt_sigaction(SIGALRM, &new, NULL); | ||
if (ret < 0) { | ||
perror("rt_sigaction"); | ||
exit(1); | ||
} | ||
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ret = rt_sigaction(SIGALRM, NULL, &old); | ||
if (ret < 0) { | ||
perror("rt_sigaction"); | ||
exit(1); | ||
} | ||
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assert(old.sa__ == (unsigned long)handler); | ||
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alarm(1); | ||
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while(!quit); | ||
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return 0; | ||
} |