diff options
| author | Geert Uytterhoeven <geert+renesas@glider.be> | 2015-04-07 20:39:19 +0200 |
|---|---|---|
| committer | Mark Brown <broonie@kernel.org> | 2015-04-07 19:41:32 +0100 |
| commit | ff61eb422024a4614f898c1c73625e222b219a5d (patch) | |
| tree | ccb5274cf076e8b0473c7dfa2408da63b51ec5c4 | |
| parent | b716c4ffc6a2b0bfbcf9619880f335be11b65708 (diff) | |
| download | lwn-ff61eb422024a4614f898c1c73625e222b219a5d.tar.gz lwn-ff61eb422024a4614f898c1c73625e222b219a5d.zip | |
spi: Make master->handle_err() callback optional to avoid crashes
If a driver doesn't implement the master->handle_err() callback and an
SPI transfer fails, the kernel will crash with a NULL pointer
dereference:
Unable to handle kernel NULL pointer dereference at virtual address 00000000
pgd = c0003000
[00000000] *pgd=80000040004003, *pmd=00000000
Internal error: Oops: 80000206 [#1] SMP ARM
Modules linked in:
CPU: 1 PID: 1 Comm: swapper/0 Not tainted 4.0.0-rc7-koelsch-05861-g1fc9fdd4add4f783 #1046
Hardware name: Generic R8A7791 (Flattened Device Tree)
task: eec359c0 ti: eec54000 task.ti: eec54000
PC is at 0x0
LR is at spi_transfer_one_message+0x1cc/0x1f0
Make the master->handle_err() callback optional to avoid the crash.
Also fix a spelling mistake in the callback documentation while we're at
it.
Fixes: b716c4ffc6a2b0bf ("spi: introduce master->handle_err() callback")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Mark Brown <broonie@kernel.org>
| -rw-r--r-- | drivers/spi/spi.c | 2 | ||||
| -rw-r--r-- | include/linux/spi/spi.h | 2 |
2 files changed, 2 insertions, 2 deletions
diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index 31d4d9d997e2..771325322995 100644 --- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -851,7 +851,7 @@ out: if (msg->status == -EINPROGRESS) msg->status = ret; - if (msg->status) + if (msg->status && master->handle_err) master->handle_err(master, msg); spi_finalize_current_message(master); diff --git a/include/linux/spi/spi.h b/include/linux/spi/spi.h index 4eaac3a5227b..5685af84a64d 100644 --- a/include/linux/spi/spi.h +++ b/include/linux/spi/spi.h @@ -294,7 +294,7 @@ static inline void spi_unregister_driver(struct spi_driver *sdrv) * transfer_one_message are mutually exclusive; when both * are set, the generic subsystem does not call your * transfer_one callback. - * @handle_err: the subsystem calls the driver to handle and error that occurs + * @handle_err: the subsystem calls the driver to handle an error that occurs * in the generic implementation of transfer_one_message(). * @unprepare_message: undo any work done by prepare_message(). * @cs_gpios: Array of GPIOs to use as chip select lines; one per CS |