mirror of https://github.com/hak5/openwrt.git
65 lines
2.5 KiB
Diff
65 lines
2.5 KiB
Diff
From 0f76408d8c1cb0979f4286dd23912e6e59784b35 Mon Sep 17 00:00:00 2001
|
|
From: DENG Qingfang <dqfext@gmail.com>
|
|
Date: Thu, 19 Sep 2019 11:42:55 +0200
|
|
Subject: [PATCH] spi: spi-gpio: fix crash when num-chipselects is 0
|
|
MIME-Version: 1.0
|
|
Content-Type: text/plain; charset=UTF-8
|
|
Content-Transfer-Encoding: 8bit
|
|
|
|
If an spi-gpio was specified with num-chipselects = <0> in dts, kernel will crash:
|
|
|
|
Unable to handle kernel paging request at virtual address 32697073
|
|
pgd = (ptrval)
|
|
[32697073] *pgd=00000000
|
|
Internal error: Oops: 5 [# 1] SMP ARM
|
|
Modules linked in:
|
|
CPU: 2 PID: 1 Comm: swapper/0 Not tainted 4.19.72 #0
|
|
Hardware name: Generic DT based system
|
|
PC is at validate_desc+0x28/0x80
|
|
LR is at gpiod_direction_output+0x14/0x128
|
|
...
|
|
[<c0544db4>] (validate_desc) from [<c0545228>] (gpiod_direction_output+0x14/0x128)
|
|
[<c0545228>] (gpiod_direction_output) from [<c05fa714>] (spi_gpio_setup+0x58/0x64)
|
|
[<c05fa714>] (spi_gpio_setup) from [<c05f7258>] (spi_setup+0x12c/0x148)
|
|
[<c05f7258>] (spi_setup) from [<c05f7330>] (spi_add_device+0xbc/0x12c)
|
|
[<c05f7330>] (spi_add_device) from [<c05f7f74>] (spi_register_controller+0x838/0x924)
|
|
[<c05f7f74>] (spi_register_controller) from [<c05fa494>] (spi_bitbang_start+0x108/0x120)
|
|
[<c05fa494>] (spi_bitbang_start) from [<c05faa34>] (spi_gpio_probe+0x314/0x338)
|
|
[<c05faa34>] (spi_gpio_probe) from [<c05a844c>] (platform_drv_probe+0x34/0x70)
|
|
|
|
The cause is spi_gpio_setup() did not check if the spi-gpio has chipselect pins
|
|
before setting their direction and results in derefing an invalid pointer.
|
|
|
|
The bug is spotted in kernel 4.19.72 on OpenWrt, and does not occur in 4.14.
|
|
|
|
There is a similar fix upstream 249e2632dcd0509b8f8f296f5aabf4d48dfd6da8.
|
|
|
|
Ref: https://patchwork.kernel.org/patch/11150619/
|
|
Cc: Linus Walleij <linus.walleij@linaro.org>
|
|
Cc: stable@vger.kernel.org
|
|
Signed-off-by: DENG Qingfang <dqfext@gmail.com>
|
|
Signed-off-by: Petr Štetiar <ynezz@true.cz>
|
|
---
|
|
drivers/spi/spi-gpio.c | 10 ++++++----
|
|
1 file changed, 6 insertions(+), 4 deletions(-)
|
|
|
|
--- a/drivers/spi/spi-gpio.c
|
|
+++ b/drivers/spi/spi-gpio.c
|
|
@@ -242,10 +242,12 @@ static int spi_gpio_setup(struct spi_dev
|
|
* The CS GPIOs have already been
|
|
* initialized from the descriptor lookup.
|
|
*/
|
|
- cs = spi_gpio->cs_gpios[spi->chip_select];
|
|
- if (!spi->controller_state && cs)
|
|
- status = gpiod_direction_output(cs,
|
|
- !(spi->mode & SPI_CS_HIGH));
|
|
+ if (spi_gpio->has_cs) {
|
|
+ cs = spi_gpio->cs_gpios[spi->chip_select];
|
|
+ if (!spi->controller_state && cs)
|
|
+ status = gpiod_direction_output(cs,
|
|
+ !(spi->mode & SPI_CS_HIGH));
|
|
+ }
|
|
|
|
if (!status)
|
|
status = spi_bitbang_setup(spi);
|