[PATCH] gpio: wcd934x: Fix shift-out-of-bounds error

From: Srinivas Kandagatla
Date: Tue Mar 09 2021 - 05:20:25 EST


bit-mask for pins 0 to 4 is BIT(0) to BIT(4) however we ended up with BIT(n - 1)
which is not right, and this was caught by below usban check

UBSAN: shift-out-of-bounds in /workspace/dev/linux/drivers/gpio/gpio-wcd934x.c:34:14
qcom-q6v5-mss 4080000.remoteproc: failed to acquire pdc reset
remoteproc remoteproc2: releasing 4080000.remoteproc
shift exponent 4294967295 is too large for 64-bit type 'long unsigned int'
CPU: 6 PID: 155 Comm: kworker/6:2 Not tainted 5.12.0-rc1-00045-g508b7280ec3d-dirty #1396
Hardware name: Thundercomm Dragonboard 845c (DT)

Call trace:
dump_backtrace+0x0/0x1c0
show_stack+0x18/0x68
dump_stack+0xd8/0x134
ubsan_epilogue+0x10/0x58
__ubsan_handle_shift_out_of_bounds+0xf8/0x168
wcd_gpio_get_direction+0xc8/0xd8
gpiochip_add_data_with_key+0x4ac/0xe78
devm_gpiochip_add_data_with_key+0x30/0x90
wcd_gpio_probe+0xc8/0x118
platform_probe+0x6c/0x118
really_probe+0x24c/0x418
driver_probe_device+0x68/0xf0
__device_attach_driver+0xb4/0x110

Fixes: 59c324683400 ("gpio: wcd934x: Add support to wcd934x gpio controller")
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@xxxxxxxxxx>
---
drivers/gpio/gpio-wcd934x.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpio/gpio-wcd934x.c b/drivers/gpio/gpio-wcd934x.c
index 1cbce5990855..97e6caedf1f3 100644
--- a/drivers/gpio/gpio-wcd934x.c
+++ b/drivers/gpio/gpio-wcd934x.c
@@ -7,7 +7,7 @@
#include <linux/slab.h>
#include <linux/of_device.h>

-#define WCD_PIN_MASK(p) BIT(p - 1)
+#define WCD_PIN_MASK(p) BIT(p)
#define WCD_REG_DIR_CTL_OFFSET 0x42
#define WCD_REG_VAL_CTL_OFFSET 0x43
#define WCD934X_NPINS 5
--
2.21.0