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From: will.deacon@arm.com (Will Deacon)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH 1/3] ARM: perf: Check that current->mm is alive before getting user callchain
Date: Thu, 3 Jul 2014 18:53:07 +0100	[thread overview]
Message-ID: <20140703175306.GG17372@arm.com> (raw)
In-Reply-To: <1403881067-22690-2-git-send-email-jean.pihet@linaro.org>

On Fri, Jun 27, 2014 at 03:57:45PM +0100, Jean Pihet wrote:
> An event may occur when an mm is already released.
> 
> As per commit 20afc60f892d285fde179ead4b24e6a7938c2f1b
>  'x86, perf: Check that current->mm is alive before getting user callchain'
> 
> Signed-off-by: Jean Pihet <jean.pihet@linaro.org>
> Cc: Will Deacon <will.deacon@arm.com>
> ---

Acked-by: Will Deacon <will.deacon@arm.com>

>  arch/arm/kernel/perf_event.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/arch/arm/kernel/perf_event.c b/arch/arm/kernel/perf_event.c
> index 4238bcb..6493c4c 100644
> --- a/arch/arm/kernel/perf_event.c
> +++ b/arch/arm/kernel/perf_event.c
> @@ -590,6 +590,10 @@ perf_callchain_user(struct perf_callchain_entry *entry, struct pt_regs *regs)
>  	}
>  
>  	perf_callchain_store(entry, regs->ARM_pc);
> +
> +	if (!current->mm)
> +		return;
> +
>  	tail = (struct frame_tail __user *)regs->ARM_fp - 1;
>  
>  	while ((entry->nr < PERF_MAX_STACK_DEPTH) &&
> -- 
> 1.8.1.2
> 
> 

  reply	other threads:[~2014-07-03 17:53 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-06-27 14:57 [PATCH 0/3] ARM: perf: allow tracing with kernel tracepoints events Jean Pihet
2014-06-27 14:57 ` [PATCH 1/3] ARM: perf: Check that current->mm is alive before getting user callchain Jean Pihet
2014-07-03 17:53   ` Will Deacon [this message]
2014-06-27 14:57 ` [PATCH 2/3] ARM: perf: disable the pagefault handler when reading from user space Jean Pihet
2014-07-03 17:52   ` Will Deacon
2014-07-07 13:40     ` Jean Pihet
2014-06-27 14:57 ` [PATCH 3/3] ARM: perf: allow tracing with kernel tracepoints events Jean Pihet
2014-07-03 17:54   ` Will Deacon
2014-07-07 13:42     ` Jean Pihet
  -- strict thread matches above, loose matches on Subject: below --
2014-07-07 13:45 [PATCH 0/3] " Jean Pihet
2014-07-07 13:45 ` [PATCH 1/3] ARM: perf: Check that current->mm is alive before getting user callchain Jean Pihet

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