linux-kernel - Re: [PATCH] x86, perf: check that current->mm alive before getting user callchain

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: <1314710043.5812.1.camel@twins>
Date:	Tue, 30 Aug 2011 15:14:03 +0200
From:	Peter Zijlstra <a.p.zijlstra@...llo.nl>
To:	Andrey Vagin <avagin@...nvz.org>
Cc:	linux-kernel@...r.kernel.org, Paul Mackerras <paulus@...ba.org>,
	Ingo Molnar <mingo@...e.hu>,
	Arnaldo Carvalho de Melo <acme@...stprotocols.net>
Subject: Re: [PATCH] x86, perf: check that current->mm alive before getting
 user callchain

On Tue, 2011-08-30 at 12:32 +0400, Andrey Vagin wrote:
> An event may occurs when mm is already released.

> Signed-off-by: Andrey Vagin <avagin@...nvz.org>
> ---
>  arch/x86/kernel/cpu/perf_event.c |    3 +++
>  1 files changed, 3 insertions(+), 0 deletions(-)
> 
> diff --git a/arch/x86/kernel/cpu/perf_event.c b/arch/x86/kernel/cpu/perf_event.c
> index 4ee3abf..cfa62ec 100644
> --- a/arch/x86/kernel/cpu/perf_event.c
> +++ b/arch/x86/kernel/cpu/perf_event.c
> @@ -1900,6 +1900,9 @@ perf_callchain_user(struct perf_callchain_entry *entry, struct pt_regs *regs)
>  
>  	perf_callchain_store(entry, regs->ip);
>  
> +	if (!current->mm)
> +		return;
> +
>  	if (perf_callchain_user32(regs, entry))
>  		return;
>  

Thanks!
--
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/