Arch Linux

gneg

Member

Registered: 2023-10-31

Posts: 3

gdb: Cannot insert breakpoint 1. Cannot access memory at address 0x

Hi! I can’t debug C code, because GDB can’t access memory at address 0x1139.

This happens in all programs I’m trying to debug. For example, I’ve made a super
simple C program:

#include <stdio.h>

int main(void) {
	for (;;) {
		puts("hi");
	}
}

I compiled it with

gcc -ggdb3 main.c -o main

Then I tried to debug it with

gdb main

Here’s what happened next:

GNU gdb (GDB) 17.1
Copyright <...>

Reading symbols from main...
(gdb) list
1	#include <stdio.h>
2	
3	int main(void) {
4		for (;;) {
5			puts("hi");
6		}
7	}
(gdb) break main
Breakpoint 1 at 0x113d: file main.c, line 5.
(gdb) info break
Num     Type           Disp Enb Address            What
1       breakpoint     keep y   0x000000000000113d in main at main.c:5
(gdb) run
Starting program: /tmp/main 
❌️ Warning:
Cannot insert breakpoint 1.
Cannot access memory at address 0x1139

Interestingly, the address of the break point is 0x113d, but GDB can’t access 0x1139.

I’ve searched the internet about this, but haven’t found anything helpful. What I’ve seen:

• Gentoo: gdb accepts no breakpoint. They talk about “CONFIG_PROC_
  MEM_FORCE_PTRACE.” I don’t know  what it is.

• Gentoo: GDB "Cannot Insert Breakpoint." This guy’s GDB doesn’t work
  because his kernel is hardened. As far as I know, my kernel is not hardened.
  I use regular linux-lts.

• Arch: GDB can't insert breakpoint. This guy has a problem with /proc/sys/
  kernel/yama/ptrace_scope. I can set it to 0, but it doesn’t help.

Other questions I’ve seen about this problem are unrelated, I think.

By the way, Delve, a Go debugger, works fine.

Help me fix my GDB!

dimich

Member

From: Kharkiv, Ukraine

Registered: 2009-11-03

Posts: 515

Re: gdb: Cannot insert breakpoint 1. Cannot access memory at address 0x

$ gdb --nh main

Does this work? If it does, show your ~/.config/gdb/*