Re: gdb/gdbserver uclibc illegal instruction

Re: gdb/gdbserver uclibc illegal instruction

[Paul Blacquiere]

Resolution in thread: 	Re: Howto single step from beginning

Built uclibc from snapshot dated 02/02/06 - this fixed the issue.



----- Forwarded message from blacq@slingshot.co.nz -----
    Date: Mon, 23 Jan 2006 17:12:24 +1300
    From: Paul Blacquiere <blacq@slingshot.co.nz>
Reply-To: Paul Blacquiere <blacq@slingshot.co.nz>
 Subject: gdb/gdbserver uclibc illegal instruction
      To: "gdb@sourceware.org" <gdb@sourceware.org>

Hi,

I am attempting to run gdb/gdbserver on an Arm Linux board built using the
uclibc libraries.

Attempting to run an app causes an illegal instruction error (the simple hello
world app obviously runs normally).  One oddity is that the address that it
reports seems to contain a valid arm instruction.

I have seen some old posts on the forum, but being over two years old and
previous versions, I have ignored.

My uclibc version is 0.9.28
GCC 3.4.5
Linux kernel 2.6.12
GDB 6.3 (am building 6.4 at the moment)

Any thoughts or comments welcome and appreciated.


PaulB.

----- End forwarded message -----

gdb/gdbserver uclibc illegal instruction

[Paul Blacquiere]

Hi,

I am attempting to run gdb/gdbserver on an Arm Linux board built using the
uclibc libraries.

Attempting to run an app causes an illegal instruction error (the simple hello
world app obviously runs normally).  One oddity is that the address that it
reports seems to contain a valid arm instruction.

I have seen some old posts on the forum, but being over two years old and
previous versions, I have ignored.

My uclibc version is 0.9.28
GCC 3.4.5
Linux kernel 2.6.12
GDB 6.3 (am building 6.4 at the moment)

Any thoughts or comments welcome and appreciated.


PaulB.

Re: gdb/gdbserver uclibc illegal instruction

[Daniel Jacobowitz]

On Mon, Jan 23, 2006 at 05:12:24PM +1300, Paul Blacquiere wrote:
> Hi,
> 
> I am attempting to run gdb/gdbserver on an Arm Linux board built using the
> uclibc libraries.
> 
> Attempting to run an app causes an illegal instruction error (the simple hello
> world app obviously runs normally).  One oddity is that the address that it
> reports seems to contain a valid arm instruction.

And what instruction is it?  What's around that instruction?  Could you
post a complete session log?

There's not enough information here to help you, sorry.

-- 
Daniel Jacobowitz
CodeSourcery

Re: gdb/gdbserver uclibc illegal instruction

[Paul Blacquiere]

Hi,

session log:

1	#include <stdio.h>
2
3	int main( int argc, char *argv[] ) {
4		printf("Hello World....\n\n");
5
6		return 0;
7	}
Starting program: /home/blacq/src/bin/hello

Program received signal SIGILL, Illegal instruction.
0x40003360 in ?? ()
Dump of assembler code from 0x40003350 to 0x40003370:
0x40003350:	str	r6, [r1]
0x40003354:	str	r12, [r11, #-304]
0x40003358:	str	lr, [r11, #-280]
0x4000335c:	bl	0x40000b60
0x40003360:	bl	0x40001670
0x40003364:	ldr	r3, [pc, #2304]	; 0x40003c6c
0x40003368:	ldr	r3, [r10, r3]
0x4000336c:	ldr	r2, [r3]
End of assembler dump.
Dump of assembler code from 0x40001670 to 0x400016a0:
0x40001670:	stmdb	sp!, {r4, r5, r6, r7, r8, r10, lr}
0x40001674:	ldr	r10, [pc, #668]	; 0x40001918
0x40001678:	ldr	r6, [pc, #668]	; 0x4000191c
0x4000167c:	add	r10, pc, r10
0x40001680:	ldr	lr, [r10, r6]
0x40001684:	ldr	r0, [lr]
0x40001688:	cmn	r0, #1	; 0x1
0x4000168c:	sub	sp, sp, #88	; 0x58
0x40001690:	beq	0x40001910
0x40001694:	cmp	r0, #0	; 0x0
0x40001698:	bne	0x400018ac
0x4000169c:	ldr	r7, [pc, #636]	; 0x40001920
End of assembler dump.

Hope this gives some insight.

PaulB.

Quoting Daniel Jacobowitz <drow@false.org>:

> On Mon, Jan 23, 2006 at 05:12:24PM +1300, Paul Blacquiere wrote:
>> Hi,
>>
>> I am attempting to run gdb/gdbserver on an Arm Linux board built using the
>> uclibc libraries.
>>
>> Attempting to run an app causes an illegal instruction error (the 
>> simple hello
>> world app obviously runs normally).  One oddity is that the address that it
>> reports seems to contain a valid arm instruction.
>
> And what instruction is it?  What's around that instruction?  Could you
> post a complete session log?
>
> There's not enough information here to help you, sorry.
>
> --
> Daniel Jacobowitz
> CodeSourcery

Re: gdb/gdbserver uclibc illegal instruction

[Daniel Jacobowitz]

On Tue, Jan 24, 2006 at 05:48:32PM +1300, Paul Blacquiere wrote:
> Hope this gives some insight.

Not really, I'm afraid.  At a guess, something has messed up the CPSR
T bit (Thumb state)?

-- 
Daniel Jacobowitz
CodeSourcery