[Segfault] Nasty section error How to debug "Segment Fault" on Linux

Overview

We can get segfault by several reasons:

• Aligned access to unaligned memory (usally see in ARM NEON)

• Cross-border Access

  int temp[2] = {0};temp[22//  Segfault

• Write on read-only access

  Char " Haha " ; temp[12//  Segfault

• Others

How to find which code line results in Segfaultstep 1:debug

DEBUG flavour usually add some assert () statements about the memory alignment access.

Step 2:using GDB

If DEBUG flavour did not give any assert report, or you have a fixed all of the Assert () report, but it still aborts with SEGFA Ult. What ' s next?

Usually, we can add "-g" compiler flag and rebuild the executable, then use GDB to locate where is the Segfault.

1 /*main.c*/2#include <stdio.h>3#include <stdlib.h>4 extern intF0 ();5 extern intF2 ();6 extern intf4 ();7 intF1 ();8 intf3 ();9 intMain ()Ten { Oneprintf"Test for segfault.\n"); A     returnf4 (); - } - intF1 () the { -     returnF0 (); - } - intf3 () + { -     returnF2 (); + } A   at /*segfault.c*/ -#include <stdio.h> - CharF0 () - { -     Char*tmp ="Haha"; -tmp[0] ='h'; in     returntmp[4]; - } to CharF2 () + { -     returnF1 (); the } * Charf4 () $ {Panax Notoginseng     returnf3 (); -}

Example Code

Build and run on Terminal:

gcc main.c segfault.c-o segfault.x$. / for segfault.segmentation fault (core dumped)

Then with GDB:

$GCC-g-o3 MAIN.C segfault.c-o segfault.x$ gdb./segfault.xgnu gdb (Ubuntu7.7-0ubuntu3.1)7.7Copyright (C) theFree Software Foundation, Inc. (GDB) rstarting program:/home/jxion/jxion_porting_server/users_jxion/test_segfault/segfault.xtest forSegfault.program received signal SIGSEGV, segmentation fault.f0 () at segfault.c:66tmp[0] ='h';(gdb) bt#0F0 () at segfault.c:6#1  0x0000000000400557 inchF1 () at MAIN.C: +#2  0x000000000040058b inchF2 () at segfault.c: A#3  0x0000000000400567 inchF3 () at MAIN.C: -#4  0x000000000040059b inchF4 () at segfault.c: -#5  0x00007ffff7a35ec5 inch__libc_start_main (main=0x400440<main>, argc=1, argv=0x7fffffffd6f8, init=<optimized Out>, fini=<optimized out>, rtld_fini=<optimized Out>, stack_end=0x7fffffffd6e8) at libc-START.C:287#6  0x0000000000400482 inch_start () (GDB)

Now you can get the all info to you need.

[Segfault] Nasty section error How to debug "Segment Fault" on Linux