RGBCube/serenity
1
Fork 0
mirror of https://github.com/RGBCube/serenity synced 2025-10-31 16:52:43 +00:00
Code Issues Activity Actions

Debugger: Get entry point of debugged process

Browse source 
Also, start debugging only after execve is done
This commit is contained in:
Itamar 2020-04-04 12:10:54 +03:00 • committed by Andreas Kling
parent 984ff93406
commit 924fda19b0
1 changed files with 51 additions and 12 deletions
Download patch file Download diff file Expand all files Collapse all files

63
Applications/Debugger/main.cpp
View file

@ -25,7 +25,10 @@
*/
#include <AK/Assertions.h>
#include <AK/ByteBuffer.h>
#include <LibC/sys/arch/i386/regs.h>
#include <LibCore/File.h>
#include <LibELF/ELFImage.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
@ -70,11 +73,51 @@ void run_child_and_attach(char** argv)
ASSERT_NOT_REACHED();
}
g_pid = pid;
if (waitpid(pid, nullptr, WSTOPPED) != pid) {
perror("waitpid");
exit(1);
}
g_pid = pid;
if (ptrace(PT_ATTACH, g_pid, 0, 0) == -1) {
perror("attach");
exit(1);
}
if (waitpid(g_pid, nullptr, WSTOPPED) != g_pid) {
perror("waitpid");
exit(1);
}
// we want to continue until the exit from the 'execve' sycsall
// we do this to ensure that when we start debugging the process,
// it executes the target image, and not the forked image of the debugger
// NOTE: we only need to do this when we are debugging a new process (i.e not attaching to a process that's already running!)
if (ptrace(PT_SYSCALL, g_pid, 0, 0) == -1) {
perror("syscall");
exit(1);
}
if (waitpid(g_pid, nullptr, WSTOPPED) != g_pid) {
perror("wait_pid");
exit(1);
}
}
VirtualAddress get_entry_point(int pid)
{
auto path = String::format("/proc/%d/exe", pid);
dbg() << "path: " << path;
auto file = Core::File::construct(path);
if (!file->open(Core::File::ReadOnly)) {
fprintf(stderr, "Failed to open Debugged executable");
exit(1);
}
auto data = file->read_all();
dbg() << "data size:" << data.size();
ELFImage elf(data.data(), data.size());
return elf.entry();
}
int main(int argc, char** argv)
@ -82,21 +125,16 @@ int main(int argc, char** argv)
if (argc == 1)
return usage();
run_child_and_attach(argv);
struct sigaction sa;
memset(&sa, 0, sizeof(struct sigaction));
sa.sa_handler = handle_sigint;
sigaction(SIGINT, &sa, nullptr);
if (ptrace(PT_ATTACH, g_pid, 0, 0) == -1) {
perror("attach");
return 1;
}
if (waitpid(g_pid, nullptr, WSTOPPED) != g_pid) {
perror("waitpid");
return 1;
}
run_child_and_attach(argv);
dbg() << "pid:" << g_pid;
auto entry_point = get_entry_point(g_pid);
dbg() << "entry point:" << entry_point;
if (ptrace(PT_CONTINUE, g_pid, 0, 0) == -1) {
perror("continue");
@ -108,13 +146,14 @@ int main(int argc, char** argv)
return 1;
}
printf("hit breakpoint\n");
PtraceRegisters regs;
if (ptrace(PT_GETREGS, g_pid, &regs, 0) == -1) {
perror("getregs");
return 1;
}
printf("hit breakpoint\n");
printf("eip:0x%x\n", regs.eip);
uint32_t data = ptrace(PT_PEEK, g_pid, (void*)regs.eip, 0);