linux-mm.kvack.org archive mirror
 help / color / mirror / Atom feed
From: Dima Zavin <dima@android.com>
To: linux-kernel@vger.kernel.org
Cc: linux-mm@kvack.org, Dima Zavin <dima@android.com>
Subject: [PATCH] mm: add a might_sleep_if in dma_pool_alloc
Date: Wed, 22 Sep 2010 20:52:47 -0700	[thread overview]
Message-ID: <1285213967-14052-1-git-send-email-dima@android.com> (raw)

Buggy drivers (e.g. fsl_udc) could call dma_pool_alloc from atomic
context with GFP_KERNEL. In most instances, the first pool_alloc_page
call would succeed and the sleeping functions would never be called.
This allowed the buggy drivers to slip through the cracks.

Add a might_sleep_if checking for __GFP_WAIT in flags.

Signed-off-by: Dima Zavin <dima@android.com>
---
 mm/dmapool.c |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)

diff --git a/mm/dmapool.c b/mm/dmapool.c
index 3df0637..4df2de7 100644
--- a/mm/dmapool.c
+++ b/mm/dmapool.c
@@ -311,6 +311,8 @@ void *dma_pool_alloc(struct dma_pool *pool, gfp_t mem_flags,
 	size_t offset;
 	void *retval;
 
+	might_sleep_if(mem_flags & __GFP_WAIT);
+
 	spin_lock_irqsave(&pool->lock, flags);
  restart:
 	list_for_each_entry(page, &pool->page_list, page_list) {
-- 
1.6.6

--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org.  For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>

                 reply	other threads:[~2010-09-23  3:53 UTC|newest]

Thread overview: [no followups] expand[flat|nested]  mbox.gz  Atom feed

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=1285213967-14052-1-git-send-email-dima@android.com \
    --to=dima@android.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).