Aren
/
toaruos
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

ptrace: add demo tool to test overwriting syscall number

This commit is contained in:
K. Lange 2023-10-08 08:34:56 +09:00
parent 453486bc52
commit 48dcf55a5d
1 changed files with 69 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

69
apps/test-ptrace-syscall.c Normal file
View File

@ -0,0 +1,69 @@
#include <errno.h>
#include <string.h>
#include <stdio.h>
#include <unistd.h>
#include <fcntl.h>
#include <getopt.h>
#include <signal.h>
#include <sys/ptrace.h>
#include <sys/wait.h>
#include <sys/signal.h>
#include <sys/signal_defs.h>
#include <sys/sysfunc.h>
#include <sys/utsname.h>
#include <sys/time.h>
#include <sys/socket.h>
#include <sys/uregs.h>
#include <syscall_nums.h>
int main(int argc, char * argv[]) {
pid_t p = fork();
if (!p) {
if (ptrace(PTRACE_TRACEME, 0, NULL, NULL) < 0) {
fprintf(stderr, "%s: ptrace: %s\n", argv[0], strerror(errno));
return 1;
}
execvp(argv[optind], &argv[optind]);
return 1;
}
while (1) {
int status = 0;
pid_t res = waitpid(p, &status, WSTOPPED);
if (res < 0) {
fprintf(stderr, "%s: waitpid: %s\n", argv[0], strerror(errno));
} else {
if (WIFSTOPPED(status)) {
if (WSTOPSIG(status) == SIGTRAP) {
struct URegs regs;
ptrace(PTRACE_GETREGS, p, NULL, &regs);
/* Event type */
int event = (status >> 16) & 0xFF;
switch (event) {
case PTRACE_EVENT_SYSCALL_ENTER:
if (uregs_syscall_num(&regs) == SYS_SLEEP) {
fprintf(stderr, "%s: sleep called, rewriting to yield\n", argv[0]);
uregs_syscall_num(&regs) = SYS_YIELD;
ptrace(PTRACE_SETREGS, p, NULL, &regs);
}
break;
default:
break;
}
ptrace(PTRACE_CONT, p, NULL, NULL);
} else {
ptrace(PTRACE_CONT, p, NULL, (void*)(uintptr_t)WSTOPSIG(status));
}
} else if (WIFSIGNALED(status)) {
return 0;
} else if (WIFEXITED(status)) {
return 0;
}
}
}
return 0;
}