* [PATCH] mfd: menelaus: remove null pointer dereference
@ 2014-08-09 16:40 Himangi Saraogi
2014-08-21 8:37 ` Lee Jones
0 siblings, 1 reply; 2+ messages in thread
From: Himangi Saraogi @ 2014-08-09 16:40 UTC (permalink / raw)
To: Samuel Ortiz, Lee Jones, linux-kernel; +Cc: Julia Lawall
If vtg is NULL, it is not possible to access its mode_reg field. At all
sites where the static function menelaus_set_voltage is called, the first
argument is the address of a structure defined in the file. So, the null
test is unnecessary and is removed. Also, a label is done away with.
This problem was found using the following Coccinelle semantic match:
// <smpl>
@@
expression E, E1;
identifier f;
statement S1,S2,S3;
@@
* if (E == NULL)
{
... when != if (E == NULL) S1 else S2
when != E = E1
* E->f
... when any
return ...;
}
else S3
// </smpl>
Signed-off-by: Himangi Saraogi <himangi774@gmail.com>
Acked-by: Julia Lawall <julia.lawall@lip6.fr>
---
Not compile tested.
drivers/mfd/menelaus.c | 3 ---
1 file changed, 3 deletions(-)
diff --git a/drivers/mfd/menelaus.c b/drivers/mfd/menelaus.c
index 5e2667a..18ff56f 100644
--- a/drivers/mfd/menelaus.c
+++ b/drivers/mfd/menelaus.c
@@ -466,8 +466,6 @@ static int menelaus_set_voltage(const struct menelaus_vtg *vtg, int mV,
struct i2c_client *c = the_menelaus->client;
mutex_lock(&the_menelaus->lock);
- if (!vtg)
- goto set_voltage;
ret = menelaus_read_reg(vtg->vtg_reg);
if (ret < 0)
@@ -482,7 +480,6 @@ static int menelaus_set_voltage(const struct menelaus_vtg *vtg, int mV,
ret = menelaus_write_reg(vtg->vtg_reg, val);
if (ret < 0)
goto out;
-set_voltage:
ret = menelaus_write_reg(vtg->mode_reg, mode);
out:
mutex_unlock(&the_menelaus->lock);
--
1.9.1
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH] mfd: menelaus: remove null pointer dereference
2014-08-09 16:40 [PATCH] mfd: menelaus: remove null pointer dereference Himangi Saraogi
@ 2014-08-21 8:37 ` Lee Jones
0 siblings, 0 replies; 2+ messages in thread
From: Lee Jones @ 2014-08-21 8:37 UTC (permalink / raw)
To: Himangi Saraogi; +Cc: Samuel Ortiz, linux-kernel, Julia Lawall
On Sat, 09 Aug 2014, Himangi Saraogi wrote:
> If vtg is NULL, it is not possible to access its mode_reg field. At all
> sites where the static function menelaus_set_voltage is called, the first
> argument is the address of a structure defined in the file. So, the null
> test is unnecessary and is removed. Also, a label is done away with.
>
> This problem was found using the following Coccinelle semantic match:
>
> // <smpl>
> @@
> expression E, E1;
> identifier f;
> statement S1,S2,S3;
> @@
>
> * if (E == NULL)
> {
> ... when != if (E == NULL) S1 else S2
> when != E = E1
> * E->f
> ... when any
> return ...;
> }
> else S3
> // </smpl>
>
> Signed-off-by: Himangi Saraogi <himangi774@gmail.com>
> Acked-by: Julia Lawall <julia.lawall@lip6.fr>
> ---
> Not compile tested.
> drivers/mfd/menelaus.c | 3 ---
> 1 file changed, 3 deletions(-)
Applied, thanks.
> diff --git a/drivers/mfd/menelaus.c b/drivers/mfd/menelaus.c
> index 5e2667a..18ff56f 100644
> --- a/drivers/mfd/menelaus.c
> +++ b/drivers/mfd/menelaus.c
> @@ -466,8 +466,6 @@ static int menelaus_set_voltage(const struct menelaus_vtg *vtg, int mV,
> struct i2c_client *c = the_menelaus->client;
>
> mutex_lock(&the_menelaus->lock);
> - if (!vtg)
> - goto set_voltage;
>
> ret = menelaus_read_reg(vtg->vtg_reg);
> if (ret < 0)
> @@ -482,7 +480,6 @@ static int menelaus_set_voltage(const struct menelaus_vtg *vtg, int mV,
> ret = menelaus_write_reg(vtg->vtg_reg, val);
> if (ret < 0)
> goto out;
> -set_voltage:
> ret = menelaus_write_reg(vtg->mode_reg, mode);
> out:
> mutex_unlock(&the_menelaus->lock);
--
Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org │ Open source software for ARM SoCs
Follow Linaro: Facebook | Twitter | Blog
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2014-08-09 16:40 [PATCH] mfd: menelaus: remove null pointer dereference Himangi Saraogi
2014-08-21 8:37 ` Lee Jones
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