@@ -1039,9 +1039,6 @@ void spi_finalize_current_message(struct spi_master *master)
spin_lock_irqsave(&master->queue_lock, flags);
mesg = master->cur_msg;
- master->cur_msg = NULL;
-
- queue_kthread_work(&master->kworker, &master->pump_messages);
spin_unlock_irqrestore(&master->queue_lock, flags);
spi_unmap_msg(master, mesg);
@@ -1054,9 +1051,13 @@ void spi_finalize_current_message(struct spi_master *master)
}
}
- trace_spi_message_done(mesg);
-
+ spin_lock_irqsave(&master->queue_lock, flags);
+ master->cur_msg = NULL;
master->cur_msg_prepared = false;
+ queue_kthread_work(&master->kworker, &master->pump_messages);
+ spin_unlock_irqrestore(&master->queue_lock, flags);
+
+ trace_spi_message_done(mesg);
mesg->state = NULL;
if (mesg->complete)
This is a note to let you know that I have just added a patch titled spi: fix race freeing dummy_tx/rx before it is unmapped to the linux-3.16.y-queue branch of the 3.16.y-ckt extended stable tree which can be found at: http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-3.16.y-queue This patch is scheduled to be released in version 3.16.7-ckt15. If you, or anyone else, feels it should not be added to this tree, please reply to this email. For more information about the 3.16.y-ckt tree, see https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable Thanks. -Luis ------ From a1800bf1690821717e58399f8ae698bf0e6a7ae9 Mon Sep 17 00:00:00 2001 From: Martin Sperl <kernel@martin.sperl.org> Date: Sun, 10 May 2015 07:50:45 +0000 Subject: spi: fix race freeing dummy_tx/rx before it is unmapped MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit commit 8e76ef88f607174082023f50b87fe12dcdbe5db5 upstream. Fix a race (with some kernel configurations) where a queued master->pump_messages runs and frees dummy_tx/rx before spi_unmap_msg is running (or is finished). This results in the following messages: BUG: Bad page state in process page:db7ba030 count:0 mapcount:0 mapping: (null) index:0x0 flags: 0x200(arch_1) page dumped because: PAGE_FLAGS_CHECK_AT_PREP flag set ... Reported-by: Noralf Trønnes <noralf@tronnes.org> Suggested-by: Noralf Trønnes <noralf@tronnes.org> Tested-by: Noralf Trønnes <noralf@tronnes.org> Signed-off-by: Martin Sperl <kernel@martin.sperl.org> Signed-off-by: Mark Brown <broonie@kernel.org> Signed-off-by: Luis Henriques <luis.henriques@canonical.com> --- drivers/spi/spi.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-)