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| author | Marc Zyngier <maz@kernel.org> | 2021-07-25 19:08:30 +0100 |
|---|---|---|
| committer | Linus Walleij <linus.walleij@linaro.org> | 2021-08-10 14:47:59 +0200 |
| commit | 1b73e588f47397dee6e4bdfd953e0306c60b5fe5 (patch) | |
| tree | db955633b15ef5dce93a8cb17aabd6949bbc1247 /drivers/pinctrl | |
| parent | a022135a19a1b2f8ee1f9e90d5d9de419543904c (diff) | |
| download | linux-1b73e588f47397dee6e4bdfd953e0306c60b5fe5.tar.bz2 | |
pinctrl: stmfx: Fix hazardous u8[] to unsigned long cast
Casting a small array of u8 to an unsigned long is *never* OK:
- it does funny thing when the array size is less than that of a long,
as it accesses random places in the stack
- it makes everything even more fun with a BE kernel
Fix this by building the unsigned long used as a bitmap byte by byte,
in a way that works across endianess and has no undefined behaviours.
An extra BUILD_BUG_ON() catches the unlikely case where the array
would be larger than a single unsigned long.
Fixes: 1490d9f841b1 ("pinctrl: Add STMFX GPIO expander Pinctrl/GPIO driver")
Signed-off-by: Marc Zyngier <maz@kernel.org>
Cc: stable@vger.kernel.org
Cc: Amelie Delaunay <amelie.delaunay@foss.st.com>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com>
Cc: Alexandre Torgue <alexandre.torgue@foss.st.com>
Link: https://lore.kernel.org/r/20210725180830.250218-1-maz@kernel.org
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Diffstat (limited to 'drivers/pinctrl')
| -rw-r--r-- | drivers/pinctrl/pinctrl-stmfx.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/drivers/pinctrl/pinctrl-stmfx.c b/drivers/pinctrl/pinctrl-stmfx.c index 008c83107a3c..5fa2488fae87 100644 --- a/drivers/pinctrl/pinctrl-stmfx.c +++ b/drivers/pinctrl/pinctrl-stmfx.c @@ -566,7 +566,7 @@ static irqreturn_t stmfx_pinctrl_irq_thread_fn(int irq, void *dev_id) u8 pending[NR_GPIO_REGS]; u8 src[NR_GPIO_REGS] = {0, 0, 0}; unsigned long n, status; - int ret; + int i, ret; ret = regmap_bulk_read(pctl->stmfx->map, STMFX_REG_IRQ_GPI_PENDING, &pending, NR_GPIO_REGS); @@ -576,7 +576,9 @@ static irqreturn_t stmfx_pinctrl_irq_thread_fn(int irq, void *dev_id) regmap_bulk_write(pctl->stmfx->map, STMFX_REG_IRQ_GPI_SRC, src, NR_GPIO_REGS); - status = *(unsigned long *)pending; + BUILD_BUG_ON(NR_GPIO_REGS > sizeof(status)); + for (i = 0, status = 0; i < NR_GPIO_REGS; i++) + status |= (unsigned long)pending[i] << (i * 8); for_each_set_bit(n, &status, gc->ngpio) { handle_nested_irq(irq_find_mapping(gc->irq.domain, n)); stmfx_pinctrl_irq_toggle_trigger(pctl, n); |