From: William Tambe <tambewilliam@gmail.com>
To: Simon Marchi <simark@simark.ca>
Cc: gdb@sourceware.org
Subject: Re: How to disable GDB backtrace new behavior of including disassembly in backtrace ?
Date: Tue, 24 Dec 2019 12:30:00 -0000 [thread overview]
Message-ID: <CAF8i9mNg5uy9z28MnGbbMRxRk4jTn_0poswCRe0ndM-n3JJS-w@mail.gmail.com> (raw)
In-Reply-To: <4bef00a7-eccd-a9cf-807d-504fa9bb1bb4@simark.ca>
On Fri, Dec 13, 2019 at 2:48 PM Simon Marchi <simark@simark.ca> wrote:
>
> On 2019-12-13 7:09 a.m., William Tambe wrote:
> > How to disable GDB backtrace new behavior of including disassembly in
> > backtrace ?
> >
> > I have built GDB 8.3 and here is an example of output that I now see:
> >
> > bt
> > #0 0x0005ed42 in set_next_entity (se=<optimized out>,
> > cfs_rq=<optimized out>) at /linux/kernel/sched/fair.c:6844
> > 0x0005ed38 <pick_next_task_fair+492>: 80 74 li8 %7, 0x4 # 4
> > 0x0005ed3a <pick_next_task_fair+494>: b8 70 add %7, %sp
> > 0x0005ed3c <pick_next_task_fair+496>: ea 37 ld32 %3, %7
> > 0x0005ed3e <pick_next_task_fair+498>: c7 13 cpy %1, %3
> > 0x0005ed40 <pick_next_task_fair+500>: 92 10 inc8 %1, 32 # 0x20
> > => 0x0005ed42 <pick_next_task_fair+502>: ea 11 ld32 %1, %1
> > 0x0005ed44 <pick_next_task_fair+504>: ea 50 ld32 %5, %sp
> > 0x0005ed46 <pick_next_task_fair+506>: e0 d0 gip %sr
> > 0x0005ed48 <pick_next_task_fair+508>: a2 d0 4e 00 00 00
> > inc32 %sr, 78 # 0x4e
> > 0x0005ed4e <pick_next_task_fair+514>: d1 1d jnz %1, %sr
> > #1 pick_next_task_fair (rq=<optimized out>, prev=<optimized out>,
> > rf=<optimized out>) at /linux/kernel/sched/fair.c:6844
> >
> > Using an earlier version of GDB would have just shown two lines
> > without disassembly; ie:
> >
> > bt
> > #0 0x0005ed42 in set_next_entity (se=<optimized out>,
> > cfs_rq=<optimized out>) at /linux/kernel/sched/fair.c:6844
> > #1 pick_next_task_fair (rq=<optimized out>, prev=<optimized out>,
> > rf=<optimized out>) at /linux/kernel/sched/fair.c:6844
> >
> > How can I restore the GDB old behavior when using backtrace ?
> >
>
> Hi William,
>
> I have never seen this behavior. It's either a setting I have never
> encountered, or a Python script you have loaded that is providing this
> functionality (e.g. with a frame-filter).
I do not have a python script loaded.
What GDB command should I use to check whether I have a frame-filter ?
>
> Are you able to reproduce this behavior with another program? If so, could
> you send a small reproducer (small source snippet to compile + GDB commands),
Yes, I am able to reproduce it with any program that I compile; here
is a simple example where I can see the issue when breaking after
calling printf() and using the command backtrace.
---
#include <stdio.h>
void myfunc() {
printf("Hello world!\n");
}
void main () {
myfunc();
}
---
> we can try it and tell you if we see the same behavior.
I am using the following Binutils release that include GDB:
commit b5624945ea67525c0ba4ffec7a9d3f9366bf9071 (tag: binutils-2_33_1)
Author: Nick Clifton <nickc@redhat.com>
Date: Sat Oct 12 15:07:18 2019 +0100
Release 2.33.1
>
> Simon
next prev parent reply other threads:[~2019-12-24 12:30 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-12-13 12:10 William Tambe
2019-12-13 19:48 ` Simon Marchi
2019-12-24 12:30 ` William Tambe [this message]
2020-01-01 23:07 ` Simon Marchi
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