1 /* x86 variant of the amd64-solaris/context_rflags.c test. */ 2 3 #include <assert.h> 4 #include <signal.h> 5 #include <stdio.h> 6 #include <stdlib.h> 7 #include <unistd.h> 8 #include <sys/regset.h> 9 #include <sys/syscall.h> 10 #include <sys/ucontext.h> 11 12 #define OBIT(eflags) (!!((eflags) & (1 << 11))) 13 #define SBIT(eflags) (!!((eflags) & (1 << 7))) 14 15 static siginfo_t si; 16 static ucontext_t uc; 17 18 static void sighandler(int sig, siginfo_t *sip, void *arg) 19 { 20 si = *sip; 21 uc = *((ucontext_t *) arg); 22 } 23 24 int main(void) 25 { 26 struct sigaction sa; 27 pid_t pid; 28 int eflags; 29 30 sa.sa_sigaction = sighandler; 31 sa.sa_flags = SA_SIGINFO; 32 if (sigfillset(&sa.sa_mask)) { 33 perror("sigfillset"); 34 return 1; 35 } 36 if (sigaction(SIGUSR1, &sa, NULL)) { 37 perror("sigaction"); 38 return 1; 39 } 40 41 pid = getpid(); 42 43 __asm__ __volatile__( 44 /* Set overflow and sign flags. */ 45 "movl $1, %%edx\n" 46 "addl $0x7fffffff, %%edx\n" 47 48 /* Prepare syscall parameters. */ 49 "pushl %[sig]\n" 50 "pushl %[pid]\n" 51 "pushl $0xdeadbeef\n" 52 "movl %[scall], %%eax\n" 53 54 /* Trigger the signal handler. */ 55 "int $0x91\n" 56 "pushfl\n" 57 "popl %%edx\n" 58 "addl $12, %%esp\n" 59 : "=d" (eflags) 60 : [scall] "i" (SYS_kill), [pid] "a" (pid), [sig] "i" (SIGUSR1) 61 : "cc", "memory"); 62 63 printf("Values in the signal handler:\n"); 64 printf(" overflow=%d, sign=%d\n", 65 OBIT(uc.uc_mcontext.gregs[EFL]), SBIT(uc.uc_mcontext.gregs[EFL])); 66 67 printf("Values after the return from the signal handler:\n"); 68 printf(" overflow=%d, sign=%d\n", OBIT(eflags), SBIT(eflags)); 69 70 return 0; 71 } 72 73
