Bug #1094

kgdb crashes when remote debugging requested

Added by jgordeev almost 6 years ago. Updated almost 4 years ago.

Status:ClosedStart date:
Priority:NormalDue date:
Assignee:corecode% Done:

0%

Category:-
Target version:-

Description

kgdb crashes when remote debugging (-r) is requested. The crash involves
a NULL pointer dereference in libkvm.
I've found that the crash was introduced with revision 1.2 of
src/gnu/usr.bin/gdb/kgdb/kgdb.c.
In that revision the global variable 'kvm' isn't initialised if remote
debugging is requested, however it is always used. The value of 'kvm' is
passed to a libkvm function which attempts to dereference it.

History

#1 Updated by alexh over 4 years ago

Simon, is there any update on this? Did you have a chance of looking into this?

Cheers,
Alex Hornung

#2 Updated by tuxillo almost 4 years ago

Hi,

I've started a qemu booting w/ our latest i386 ISO.

# qemu -m 128 -hda root.img -cdrom dfly.iso -boot d -s

Using /boot/kernel from the ISO image, I've done:

# kgdb -r localhost:1234 /tmp/kernel

I don't get any segfault. So can you please give some instructions on how to
reproduce this crash?

Or maybe it is gone after the gdb update that took place after this bug was opened?

Thanks,
Antonio Huete

#3 Updated by corecode almost 4 years ago

Quite possible that the bug is gone. If -r works, then all is fine.

#4 Updated by tuxillo almost 4 years ago

Ok, I'm closing it as this issue seems to be gone.

Thanks,
Antonio Huete

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