2014-12-08 21:32:26

by Olof Johansson

Subject: [PATCH] gpio: bcm-kona: memory corruption fix

In one instance the base address of the internal controller state
structure is passed into a function doing writel to an offset of
the pointer passed in is used, instead of the register base.

Once I found the bug, I also went back to check for other sparse
warnings in the file, but found none. This one, however, triggered:

drivers/gpio/gpio-bcm-kona.c:552:47: warning: incorrect type in argument 1 (different address spaces)
drivers/gpio/gpio-bcm-kona.c:552:47: expected void [noderef] <asn:2>*reg_base
drivers/gpio/gpio-bcm-kona.c:552:47: got struct bcm_kona_gpio *kona_gpio
drivers/gpio/gpio-bcm-kona.c:556:47: warning: incorrect type in argument 1 (different address spaces)
drivers/gpio/gpio-bcm-kona.c:556:47: expected void [noderef] <asn:2>*reg_base
drivers/gpio/gpio-bcm-kona.c:556:47: got struct bcm_kona_gpio *kona_gpio

As far as I can tell, this bug has been here for a long time and is
not new, but I found it when hunting down another heisenbug on this
platform.

Not marking for stable since I am unaware of any upstream user of kona
on a product that would benefit from it.

Signed-off-by: Olof Johansson <[email protected]>
---
drivers/gpio/gpio-bcm-kona.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/gpio/gpio-bcm-kona.c b/drivers/gpio/gpio-bcm-kona.c
index de0801e..d552cca 100644
--- a/drivers/gpio/gpio-bcm-kona.c
+++ b/drivers/gpio/gpio-bcm-kona.c
@@ -549,11 +549,11 @@ static void bcm_kona_gpio_reset(struct bcm_kona_gpio *kona_gpio)
/* disable interrupts and clear status */
for (i = 0; i < kona_gpio->num_bank; i++) {
/* Unlock the entire bank first */
- bcm_kona_gpio_write_lock_regs(kona_gpio, i, UNLOCK_CODE);
+ bcm_kona_gpio_write_lock_regs(kona_gpio->reg_base, i, UNLOCK_CODE);
writel(0xffffffff, reg_base + GPIO_INT_MASK(i));
writel(0xffffffff, reg_base + GPIO_INT_STATUS(i));
/* Now re-lock the bank */
- bcm_kona_gpio_write_lock_regs(kona_gpio, i, LOCK_CODE);
+ bcm_kona_gpio_write_lock_regs(kona_gpio->reg_base, i, LOCK_CODE);
}
}

--
1.7.10.4

2014-12-08 23:35:19

by Ray Jui

Subject: Re: [PATCH] gpio: bcm-kona: memory corruption fix

On 12/8/2014 1:34 PM, Olof Johansson wrote:
> In one instance the base address of the internal controller state
> structure is passed into a function doing writel to an offset of
> the pointer passed in is used, instead of the register base.
>
> Once I found the bug, I also went back to check for other sparse
> warnings in the file, but found none. This one, however, triggered:
>
> drivers/gpio/gpio-bcm-kona.c:552:47: warning: incorrect type in argument 1 (different address spaces)
> drivers/gpio/gpio-bcm-kona.c:552:47: expected void [noderef] <asn:2>*reg_base
> drivers/gpio/gpio-bcm-kona.c:552:47: got struct bcm_kona_gpio *kona_gpio
> drivers/gpio/gpio-bcm-kona.c:556:47: warning: incorrect type in argument 1 (different address spaces)
> drivers/gpio/gpio-bcm-kona.c:556:47: expected void [noderef] <asn:2>*reg_base
> drivers/gpio/gpio-bcm-kona.c:556:47: got struct bcm_kona_gpio *kona_gpio
>
> As far as I can tell, this bug has been here for a long time and is
> not new, but I found it when hunting down another heisenbug on this
> platform.
>
> Not marking for stable since I am unaware of any upstream user of kona
> on a product that would benefit from it.
>
> Signed-off-by: Olof Johansson <[email protected]>

Acked-by: Ray Jui <[email protected]>

> ---
> drivers/gpio/gpio-bcm-kona.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpio/gpio-bcm-kona.c b/drivers/gpio/gpio-bcm-kona.c
> index de0801e..d552cca 100644
> --- a/drivers/gpio/gpio-bcm-kona.c
> +++ b/drivers/gpio/gpio-bcm-kona.c
> @@ -549,11 +549,11 @@ static void bcm_kona_gpio_reset(struct bcm_kona_gpio *kona_gpio)
> /* disable interrupts and clear status */
> for (i = 0; i < kona_gpio->num_bank; i++) {
> /* Unlock the entire bank first */
> - bcm_kona_gpio_write_lock_regs(kona_gpio, i, UNLOCK_CODE);
> + bcm_kona_gpio_write_lock_regs(kona_gpio->reg_base, i, UNLOCK_CODE);
> writel(0xffffffff, reg_base + GPIO_INT_MASK(i));
> writel(0xffffffff, reg_base + GPIO_INT_STATUS(i));
> /* Now re-lock the bank */
> - bcm_kona_gpio_write_lock_regs(kona_gpio, i, LOCK_CODE);
> + bcm_kona_gpio_write_lock_regs(kona_gpio->reg_base, i, LOCK_CODE);
> }
> }
>
>

2014-12-09 03:06:32

by Alexandre Courbot

Subject: Re: [PATCH] gpio: bcm-kona: memory corruption fix

On Tue, Dec 9, 2014 at 6:34 AM, Olof Johansson <[email protected]> wrote:
> In one instance the base address of the internal controller state
> structure is passed into a function doing writel to an offset of
> the pointer passed in is used, instead of the register base.
>
> Once I found the bug, I also went back to check for other sparse
> warnings in the file, but found none. This one, however, triggered:
>
> drivers/gpio/gpio-bcm-kona.c:552:47: warning: incorrect type in argument 1 (different address spaces)
> drivers/gpio/gpio-bcm-kona.c:552:47: expected void [noderef] <asn:2>*reg_base
> drivers/gpio/gpio-bcm-kona.c:552:47: got struct bcm_kona_gpio *kona_gpio
> drivers/gpio/gpio-bcm-kona.c:556:47: warning: incorrect type in argument 1 (different address spaces)
> drivers/gpio/gpio-bcm-kona.c:556:47: expected void [noderef] <asn:2>*reg_base
> drivers/gpio/gpio-bcm-kona.c:556:47: got struct bcm_kona_gpio *kona_gpio
>
> As far as I can tell, this bug has been here for a long time and is
> not new, but I found it when hunting down another heisenbug on this
> platform.

Ouch. Thanks for fixing this.

Reviewed-by: Alexandre Courbot <[email protected]>