From: Yao Qi <yao@codesourcery.com>
To: Kevin Pouget <kevin.pouget@gmail.com>
Cc: Robert Dewar <dewar@adacore.com>,
Jan Kratochvil <jan.kratochvil@redhat.com>,
Xin Tong <xerox.time.tech@gmail.com>, <gdb@sourceware.org>
Subject: Re: software breakpoint in gdb
Date: Mon, 30 Jan 2012 06:17:00 -0000 [thread overview]
Message-ID: <4F2635DA.3060805@codesourcery.com> (raw)
In-Reply-To: <CAPftXUJ8qb7BLeE+U6jn67T=27eoGn8E6MgaqhBSkCGbV70yqQ@mail.gmail.com>
On 01/30/2012 01:54 PM, Kevin Pouget wrote:
> I would be curious about why it would be "a disastrous mistake".
> Please correct me if I'm wrong in my understanding:
The real disaster is interrupt instruction may corrupt the following
instruction of breakpointed instruction, if interrupt instruction is
longer than breakpointed instruction. For example,
JMP L1:
...
INSN1 (1-byte)
L1:INSN2 (2-byte)
Supposing the length of interrupt instruction is 2-byte, when setting
breakpoint on INSN1, the INSN2 is corrupted. If the program runs JMP
instruction to L1 directly, something wrong will be executed.
--
Yao (é½å°§)
next prev parent reply other threads:[~2012-01-30 6:17 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-01-29 16:48 Xin Tong
2012-01-29 16:53 ` Jan Kratochvil
2012-01-30 0:54 ` Robert Dewar
2012-01-30 5:54 ` Kevin Pouget
2012-01-30 6:17 ` Yao Qi [this message]
2012-01-30 15:51 ` Marc Khouzam
2012-01-30 13:19 ` Robert Dewar
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