mirror of
https://github.com/ioacademy-jikim/debugging
synced 2025-06-08 08:26:14 +00:00
93 lines
2.3 KiB
C
93 lines
2.3 KiB
C
/* x86 variant of the amd64-solaris/context_gpr.c test. */
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#include <assert.h>
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#include <signal.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <unistd.h>
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#include <sys/syscall.h>
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#include <sys/ucontext.h>
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static siginfo_t si;
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static ucontext_t uc;
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/* x0 is always zero, but is visible to Valgrind as uninitialised. */
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static int x0;
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static void sighandler(int sig, siginfo_t *sip, ucontext_t *ucp)
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{
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si = *sip;
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uc = *ucp;
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ucp->uc_mcontext.gregs[ECX] = x0;
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}
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int main(void)
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{
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struct sigaction sa;
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pid_t pid;
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int eax, ebx, ecx, edx, esi, edi;
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int y0;
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/* Uninitialised, but we know px[0] is 0x0. */
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int *px = malloc(sizeof(*px));
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x0 = px[0];
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/* Uninitialised, but we know py[0] is 0x0. */
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int *py = malloc(sizeof(*py));
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y0 = py[0];
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sa.sa_handler = sighandler;
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sa.sa_flags = SA_SIGINFO;
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if (sigfillset(&sa.sa_mask)) {
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perror("sigfillset");
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return 1;
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}
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if (sigaction(SIGUSR1, &sa, NULL)) {
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perror("sigaction");
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return 1;
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}
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pid = getpid();
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__asm__ __volatile__(
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/* Set values in general purpose registers. */
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"movl %[y0], %%ebx\n"
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"movl $0xf1, %%ecx\n"
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"movl $0xf2, %%edx\n"
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"movl $0xf3, %%esi\n"
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"movl $0xf4, %%edi\n"
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/* Prepare syscall parameters. */
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"pushl %[sig]\n"
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"pushl %[pid]\n"
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"pushl $0xdeadbeef\n"
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"movl %[scall], %%eax\n"
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/* Trigger the signal handler. */
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"int $0x91\n"
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"addl $12, %%esp\n"
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: "=a" (eax), "=b" (ebx), "=c" (ecx), "=d" (edx), "=S" (esi),
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"=D" (edi)
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: [scall] "i" (SYS_kill), [pid] "a" (pid), [sig] "i" (SIGUSR1),
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[y0] "m" (y0)
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: "cc", "memory");
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printf("Values in the signal handler:\n");
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printf(" eax=%#x, edx=%#x, esi=%#x, edi=%#x\n",
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uc.uc_mcontext.gregs[EAX], uc.uc_mcontext.gregs[EDX],
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uc.uc_mcontext.gregs[ESI], uc.uc_mcontext.gregs[EDI]);
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/* Check that ebx contains an uninitialised value (origin is py[0]). */
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if (uc.uc_mcontext.gregs[EBX])
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assert(0);
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printf("Values after the return from the signal handler:\n");
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printf(" eax=%#x, edx=%#x, esi=%#x, edi=%#x\n", eax, edx, esi, edi);
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/* Check that ebx and ecx contain uninitialised values (origin is py[0]
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and px[0], respectively). */
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if (ebx || ecx)
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assert(0);
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return 0;
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}
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