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From: Bill Gatliff <bgat@billgatliff.com>
To: Bill Gatliff <bgat@billgatliff.com>,
	 gdb@sourceware.org, linuxppc-embedded@ozlabs.org
Subject: Re: Gdbserver syscall clobber
Date: Thu, 26 Jul 2007 11:28:48 -0500	[thread overview]
Message-ID: <46A8CBC0.8010909@billgatliff.com> (raw)
In-Reply-To: <20070723161512.GA3235@caradoc.them.org>

Daniel Jacobowitz wrote:
> Look around do_signal:
>
>                         regs->nip -= 4; /* Back up & retry system call */
>
> If your kernel has corrupted the register containing the syscall
> number at this point, that would explain your problem.  It will then
> do the wrong syscall.  I guess PPC only backs up one instruction.
>
>   

Found the code in do_signal, right where you said it would be.  I threw 
in a printk or two to see what's up when an ERESTARTSYS is detected, and 
started getting OOPSes all over the place.  Apparently that's not a good 
place for printk.  :)

Before I go on, can anyone confirm that gdbserver and/or strace _ever_ 
worked with circa 2.4.16 PPC kernels?



b.g.

-- 
Bill Gatliff
bgat@billgatliff.com

  reply	other threads:[~2007-07-26 16:29 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-07-16 15:43 Gdbserver syscall clobber Bill Gatliff
2007-07-16 15:53 ` Daniel Jacobowitz
2007-07-18 17:42   ` Bill Gatliff
2007-07-18 17:59   ` Bill Gatliff
2007-07-18 18:31     ` Daniel Jacobowitz
2007-07-23 15:37       ` Bill Gatliff
2007-07-23 15:38       ` Bill Gatliff
2007-07-23 16:06       ` Bill Gatliff
2007-07-23 16:15         ` Daniel Jacobowitz
2007-07-26 16:28           ` Bill Gatliff [this message]
2007-07-23 16:19         ` Andreas Schwab

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