mirror of
https://github.com/ioacademy-jikim/debugging
synced 2025-06-08 08:26:14 +00:00
93 lines
2.1 KiB
C
93 lines
2.1 KiB
C
#define _GNU_SOURCE
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#include <stdio.h>
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#include <signal.h>
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#include <unistd.h>
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#include <sys/ucontext.h>
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#include <asm/unistd.h>
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#define VAL1 0x11223344
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#define VAL2 0x44332211
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static void handler1(int sig, siginfo_t *si, ucontext_t *uc)
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{
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/* Since the handler will be called as kill leaves the kernel,
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this is replacing the kill syscall's return value. */
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if (uc->uc_mcontext.gregs[REG_EAX] != 0)
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printf("FAILED: handler2 expected eax == 0, not %d\n", uc->uc_mcontext.gregs[REG_EAX]);
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uc->uc_mcontext.gregs[REG_EAX] = VAL1;
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asm volatile (
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"movl $0, %%edx\n"
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"movl $0, %%esi\n"
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"movl $0, %%edi\n"
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: : : "edx", "esi", "edi");
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}
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static void handler2(int sig, struct sigcontext sc)
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{
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/* Since the handler will be called as kill leaves the kernel,
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this is replacing the kill syscall's return value. */
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if (sc.eax != 0)
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printf("FAILED: handler2 expected eax == 0, not %p\n", (void*)sc.eax);
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sc.eax = VAL2;
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asm volatile (
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"movl $0, %%edx\n"
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"movl $0, %%esi\n"
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"movl $0, %%edi\n"
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: : : "edx", "esi", "edi");
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}
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int main()
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{
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struct sigaction sa;
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int ret;
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int v2, v3, v4;
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sa.sa_handler = (void*)handler1;
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sa.sa_flags = SA_SIGINFO;
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sigfillset(&sa.sa_mask);
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sigaction(SIGUSR1, &sa, NULL);
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sa.sa_handler = (void*)handler2;
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sa.sa_flags = 0;
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sigfillset(&sa.sa_mask);
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sigaction(SIGUSR2, &sa, NULL);
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asm volatile (
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//"movl $0x11111111, %%ebp\n"
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"movl $0x22222222, %%edx\n"
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"movl $0x33333333, %%esi\n"
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"movl $0x44444444, %%edi\n"
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"int $0x80"
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: "=a" (ret), "=d" (v2), "=S" (v3), "=D" (v4)
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: "0" (__NR_kill), "b" (getpid()), "c" (SIGUSR1));
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printf("v2=%x v3=%x v4=%x\n", v2, v3, v4);
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if (ret == VAL1)
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printf("PASS %x\n", ret);
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else
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printf("FAIL ret=%x not %x\n", ret, VAL1);
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asm volatile (
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//"movl $0x11111111, %%ebp\n"
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"movl $0x22222222, %%edx\n"
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"movl $0x33333333, %%esi\n"
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"movl $0x44444444, %%edi\n"
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"int $0x80"
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: "=a" (ret), "=d" (v2), "=S" (v3), "=D" (v4)
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: "0" (__NR_kill), "b" (getpid()), "c" (SIGUSR2));
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printf("v2=%x v3=%x v4=%x\n", v2, v3, v4);
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if (ret == VAL2)
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printf("PASS %x\n", ret);
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else
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printf("FAIL ret=%x not %x\n", ret, VAL2);
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return 0;
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}
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