mirror of
https://github.com/ptitSeb/box64.git
synced 2024-11-23 18:04:16 +08:00
97 lines
2.2 KiB
C
97 lines
2.2 KiB
C
#define __USE_GNU
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#include <signal.h>
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#include <setjmp.h>
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#include <stdio.h>
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#include <sys/mman.h>
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#include <sys/ucontext.h>
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#include <errno.h>
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#include <string.h>
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#include <unistd.h>
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static jmp_buf context_buf;
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static void segv_handler(int sig)
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{
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printf("sig = %d\n", sig);
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siglongjmp(context_buf, 1);
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}
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void test()
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{
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if(!setjmp(context_buf)) {
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int *bad_ptr = (int*)0xffffffffdeadbeef;
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printf("*bad_ptr = %d\n", *bad_ptr);
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} else {
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printf("got bad_ptr\n");
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}
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}
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void* exec_p = NULL;
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typedef void(*vFv_t)(void);
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#define X_IP 16
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#define X_TRAPNO 20
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#define X_ERR 19
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static void segv_action(int sig, siginfo_t* info, ucontext_t* ucntx)
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{
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printf("sig = %d\n", sig);
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printf("si_addr: %zx, si_code: %d, si_errno: %d, RIP offset: %zd, TRAPERR=%d TRAPNO=%d\n",
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info->si_addr,
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info->si_code,
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info->si_errno,
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((intptr_t)ucntx->uc_mcontext.gregs[X_IP])-((intptr_t)exec_p),
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ucntx->uc_mcontext.gregs[X_ERR],
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ucntx->uc_mcontext.gregs[X_TRAPNO]
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);
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siglongjmp(context_buf, 1);
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}
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static unsigned char buff_cc[] = { 0xcc, 0xc3 };
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static unsigned char buff_cd03[] = { 0xcd, 0x03, 0xc3 };
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static unsigned char buff_cd2d[] = { 0xcd, 0x2d, 0xc3 };
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void test_cc()
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{
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memcpy(exec_p, buff_cc, sizeof(buff_cc));
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if(!setjmp(context_buf)) {
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vFv_t f = (vFv_t)exec_p;
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f();
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}
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memcpy(exec_p, buff_cd03, sizeof(buff_cd03));
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if(!setjmp(context_buf)) {
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vFv_t f = (vFv_t)exec_p;
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f();
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}
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/*memcpy(exec_p, buff_cd2d, sizeof(buff_cd2d));
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if(!setjmp(context_buf)) {
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vFv_t f = (vFv_t)exec_p;
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f();
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}*/
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}
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int main()
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{
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if(signal(SIGSEGV, segv_handler) == SIG_ERR) {
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printf("signal: Err = %d\n", errno);
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return -1;
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}
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//printf("handler = %p\n", segv_handler);
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test();
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struct sigaction action = {0};
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action.sa_flags = SA_SIGINFO | SA_RESTART | SA_NODEFER;
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action.sa_sigaction = segv_action;
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if(sigaction(SIGSEGV, &action, NULL)) {
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printf("sigaction: Err = %d\n", errno);
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return -2;
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}
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if(sigaction(SIGTRAP, &action, NULL)) {
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printf("sigaction 2: Err = %d\n", errno);
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return -2;
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}
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exec_p = mmap(NULL, 65536, PROT_READ|PROT_WRITE|PROT_EXEC, MAP_ANONYMOUS|MAP_PRIVATE, -1, 0);
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if(exec_p==MAP_FAILED) {
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printf("mmap: Err = %d\n", errno);
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return -3;
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}
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test_cc();
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return 0;
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}
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