linux-kernel - Re: [PATCH 1/1] function tracing: fix wrong position computing of stack

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <alpine.DEB.1.10.0811210813510.6447@gandalf.stny.rr.com>
Date:	Fri, 21 Nov 2008 08:14:18 -0500 (EST)
From:	Steven Rostedt <rostedt@...dmis.org>
To:	Liming Wang <liming.wang@...driver.com>
cc:	Ingo Molnar <mingo@...e.hu>, linux-kernel@...r.kernel.org
Subject: Re: [PATCH 1/1] function tracing: fix wrong position computing of
 stack_trace


On Fri, 21 Nov 2008, Liming Wang wrote:

> Impact: make output of stack_trace complete if buffer overflow
> 
> When read buffer overflows, the output of stack_trace isn't complete.
> 
> When printing records with seq_printf in t_show, if the read buffer
> has overflowed by the current record, then this record won't be printed
> to user space through read buffer, it will just be dropped in this printing.
> 
> When next printing, t_start should return the "*pos"th record, which is the one
> dropped by previous printing, but it just returns (m->private + *pos)th record.
> 
> Here we use a more sane method to implement seq_operations which can be found
> in kernel code. Thus we needn't initialize m->private.
> 
> About testing, it's not easy to overflow read buffer, but we can use
> seq_printf to print more padding bytes in t_show, then it's easy to check
> whether or not records are lost.
> 
> This commit has been tested on both condition of overflow and non overflow.
> 
> Signed-off-by: Liming Wang <liming.wang@...driver.com>

Acked-by: Steven Rostedt <srostedt@...hat.com>

-- Steve

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/