From: Stephen Boyd <sboyd@codeaurora.org>
To: Vikram Mulukutla <markivx@codeaurora.org>,
Steven Rostedt <rostedt@goodmis.org>,
Ingo Molnar <mingo@redhat.com>
Cc: linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org,
Lime Yang <limey@codeaurora.org>
Subject: Re: [PATCH] tracing: Fix unmapping loop in tracing_mark_write
Date: Mon, 09 Feb 2015 15:33:58 -0800 [thread overview]
Message-ID: <54D943E6.1030404@codeaurora.org> (raw)
In-Reply-To: <1418871056-6614-1-git-send-email-markivx@codeaurora.org>
On 12/17/14 18:50, Vikram Mulukutla wrote:
> Commit 6edb2a8a385f0cdef51dae37ff23e74d76d8a6ce introduced
> an array map_pages that contains the addresses returned by
> kmap_atomic. However, when unmapping those pages, map_pages[0]
> is unmapped before map_pages[1], breaking the nesting requirement
> as specified in the documentation for kmap_atomic/kunmap_atomic.
>
> This was caught by the highmem debug code present in kunmap_atomic.
> Fix the loop to do the unmapping properly.
>
> Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
> Reported-by: Lime Yang <limey@codeaurora.org>
> Signed-off-by: Vikram Mulukutla <markivx@codeaurora.org>
> ---
ping? What happened to this patch?
> kernel/trace/trace.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
> index ab76b7b..bceed34 100644
> --- a/kernel/trace/trace.c
> +++ b/kernel/trace/trace.c
> @@ -4931,7 +4931,7 @@ tracing_mark_write(struct file *filp, const char __user *ubuf,
> *fpos += written;
>
> out_unlock:
> - for (i = 0; i < nr_pages; i++){
> + for (i = nr_pages - 1; i >= 0; i--) {
> kunmap_atomic(map_page[i]);
> put_page(pages[i]);
> }
--
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum,
a Linux Foundation Collaborative Project
next prev parent reply other threads:[~2015-02-09 23:34 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-12-18 2:50 [PATCH] tracing: Fix unmapping loop in tracing_mark_write Vikram Mulukutla
2015-02-09 23:33 ` Stephen Boyd [this message]
2015-02-09 23:45 ` Steven Rostedt
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