* [PATCH 1/2] i2c: s3c2410: simplify getting of_device_id match data
@ 2021-04-15 9:38 ` Krzysztof Kozlowski
0 siblings, 0 replies; 8+ messages in thread
From: Krzysztof Kozlowski @ 2021-04-15 9:38 UTC (permalink / raw)
To: Krzysztof Kozlowski, linux-i2c, linux-arm-kernel,
linux-samsung-soc, linux-kernel
Cc: Marek Szyprowski, Sylwester Nawrocki, Alim Akhtar, Andrzej Hajda
Use of_device_get_match_data() to make the code slightly smaller.
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
---
drivers/i2c/busses/i2c-s3c2410.c | 9 +++------
1 file changed, 3 insertions(+), 6 deletions(-)
diff --git a/drivers/i2c/busses/i2c-s3c2410.c b/drivers/i2c/busses/i2c-s3c2410.c
index 62a903fbe912..ab928613afba 100644
--- a/drivers/i2c/busses/i2c-s3c2410.c
+++ b/drivers/i2c/busses/i2c-s3c2410.c
@@ -24,6 +24,7 @@
#include <linux/slab.h>
#include <linux/io.h>
#include <linux/of.h>
+#include <linux/of_device.h>
#include <linux/gpio/consumer.h>
#include <linux/pinctrl/consumer.h>
#include <linux/mfd/syscon.h>
@@ -156,12 +157,8 @@ MODULE_DEVICE_TABLE(of, s3c24xx_i2c_match);
*/
static inline kernel_ulong_t s3c24xx_get_device_quirks(struct platform_device *pdev)
{
- if (pdev->dev.of_node) {
- const struct of_device_id *match;
-
- match = of_match_node(s3c24xx_i2c_match, pdev->dev.of_node);
- return (kernel_ulong_t)match->data;
- }
+ if (pdev->dev.of_node)
+ return (kernel_ulong_t)of_device_get_match_data(&pdev->dev);
return platform_get_device_id(pdev)->driver_data;
}
--
2.25.1
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^ permalink raw reply related [flat|nested] 8+ messages in thread* [RFT 2/2] i2c: s3c2410: fix possible NULL pointer deref on read message after write
2021-04-15 9:38 ` Krzysztof Kozlowski
@ 2021-04-15 9:38 ` Krzysztof Kozlowski
-1 siblings, 0 replies; 8+ messages in thread
From: Krzysztof Kozlowski @ 2021-04-15 9:38 UTC (permalink / raw)
To: Krzysztof Kozlowski, linux-i2c, linux-arm-kernel,
linux-samsung-soc, linux-kernel
Cc: Marek Szyprowski, Sylwester Nawrocki, Alim Akhtar, Andrzej Hajda
Interrupt handler processes multiple message write requests one after
another, till the driver message queue is drained. However if driver
encounters a read message without preceding START, it stops the I2C
transfer as it is an invalid condition for the controller. At least the
comment describes a requirement "the controller forces us to send a new
START when we change direction". This stop results in clearing the
message queue (i2c->msg = NULL).
The code however immediately jumped back to label "retry_write" which
dereferenced the "i2c->msg" making it a possible NULL pointer
dereference.
The Coverity analysis:
1. Condition !is_msgend(i2c), taking false branch.
if (!is_msgend(i2c)) {
2. Condition !is_lastmsg(i2c), taking true branch.
} else if (!is_lastmsg(i2c)) {
3. Condition i2c->msg->flags & 1, taking true branch.
if (i2c->msg->flags & I2C_M_RD) {
4. write_zero_model: Passing i2c to s3c24xx_i2c_stop, which sets i2c->msg to NULL.
s3c24xx_i2c_stop(i2c, -EINVAL);
5. Jumping to label retry_write.
goto retry_write;
All previous calls to s3c24xx_i2c_stop() in this interrupt service
routine are followed by jumping to end of function (acknowledging
the interrupt and returning). This seems a reasonable choice also here
since message buffer was entirely emptied.
Addresses-Coverity: Explicit null dereferenced
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
---
drivers/i2c/busses/i2c-s3c2410.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/drivers/i2c/busses/i2c-s3c2410.c b/drivers/i2c/busses/i2c-s3c2410.c
index ab928613afba..4d82761e1585 100644
--- a/drivers/i2c/busses/i2c-s3c2410.c
+++ b/drivers/i2c/busses/i2c-s3c2410.c
@@ -480,7 +480,10 @@ static int i2c_s3c_irq_nextbyte(struct s3c24xx_i2c *i2c, unsigned long iicstat)
* forces us to send a new START
* when we change direction
*/
+ dev_dbg(i2c->dev,
+ "missing START before write->read\n");
s3c24xx_i2c_stop(i2c, -EINVAL);
+ break;
}
goto retry_write;
--
2.25.1
^ permalink raw reply related [flat|nested] 8+ messages in thread* [RFT 2/2] i2c: s3c2410: fix possible NULL pointer deref on read message after write
@ 2021-04-15 9:38 ` Krzysztof Kozlowski
0 siblings, 0 replies; 8+ messages in thread
From: Krzysztof Kozlowski @ 2021-04-15 9:38 UTC (permalink / raw)
To: Krzysztof Kozlowski, linux-i2c, linux-arm-kernel,
linux-samsung-soc, linux-kernel
Cc: Marek Szyprowski, Sylwester Nawrocki, Alim Akhtar, Andrzej Hajda
Interrupt handler processes multiple message write requests one after
another, till the driver message queue is drained. However if driver
encounters a read message without preceding START, it stops the I2C
transfer as it is an invalid condition for the controller. At least the
comment describes a requirement "the controller forces us to send a new
START when we change direction". This stop results in clearing the
message queue (i2c->msg = NULL).
The code however immediately jumped back to label "retry_write" which
dereferenced the "i2c->msg" making it a possible NULL pointer
dereference.
The Coverity analysis:
1. Condition !is_msgend(i2c), taking false branch.
if (!is_msgend(i2c)) {
2. Condition !is_lastmsg(i2c), taking true branch.
} else if (!is_lastmsg(i2c)) {
3. Condition i2c->msg->flags & 1, taking true branch.
if (i2c->msg->flags & I2C_M_RD) {
4. write_zero_model: Passing i2c to s3c24xx_i2c_stop, which sets i2c->msg to NULL.
s3c24xx_i2c_stop(i2c, -EINVAL);
5. Jumping to label retry_write.
goto retry_write;
All previous calls to s3c24xx_i2c_stop() in this interrupt service
routine are followed by jumping to end of function (acknowledging
the interrupt and returning). This seems a reasonable choice also here
since message buffer was entirely emptied.
Addresses-Coverity: Explicit null dereferenced
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
---
drivers/i2c/busses/i2c-s3c2410.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/drivers/i2c/busses/i2c-s3c2410.c b/drivers/i2c/busses/i2c-s3c2410.c
index ab928613afba..4d82761e1585 100644
--- a/drivers/i2c/busses/i2c-s3c2410.c
+++ b/drivers/i2c/busses/i2c-s3c2410.c
@@ -480,7 +480,10 @@ static int i2c_s3c_irq_nextbyte(struct s3c24xx_i2c *i2c, unsigned long iicstat)
* forces us to send a new START
* when we change direction
*/
+ dev_dbg(i2c->dev,
+ "missing START before write->read\n");
s3c24xx_i2c_stop(i2c, -EINVAL);
+ break;
}
goto retry_write;
--
2.25.1
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^ permalink raw reply related [flat|nested] 8+ messages in thread
* Re: [PATCH 1/2] i2c: s3c2410: simplify getting of_device_id match data
2021-04-15 9:38 ` Krzysztof Kozlowski
@ 2021-04-15 9:45 ` Sylwester Nawrocki
-1 siblings, 0 replies; 8+ messages in thread
From: Sylwester Nawrocki @ 2021-04-15 9:45 UTC (permalink / raw)
To: Krzysztof Kozlowski, linux-i2c, linux-arm-kernel,
linux-samsung-soc, linux-kernel
Cc: Marek Szyprowski, Alim Akhtar, Andrzej Hajda
On 15.04.2021 11:38, Krzysztof Kozlowski wrote:
> Use of_device_get_match_data() to make the code slightly smaller.
>
> Signed-off-by: Krzysztof Kozlowski<krzysztof.kozlowski@canonical.com>
Reviewed-by: Sylwester Nawrocki <snawrocki@kernel.org>
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH 1/2] i2c: s3c2410: simplify getting of_device_id match data
@ 2021-04-15 9:45 ` Sylwester Nawrocki
0 siblings, 0 replies; 8+ messages in thread
From: Sylwester Nawrocki @ 2021-04-15 9:45 UTC (permalink / raw)
To: Krzysztof Kozlowski, linux-i2c, linux-arm-kernel,
linux-samsung-soc, linux-kernel
Cc: Marek Szyprowski, Alim Akhtar, Andrzej Hajda
On 15.04.2021 11:38, Krzysztof Kozlowski wrote:
> Use of_device_get_match_data() to make the code slightly smaller.
>
> Signed-off-by: Krzysztof Kozlowski<krzysztof.kozlowski@canonical.com>
Reviewed-by: Sylwester Nawrocki <snawrocki@kernel.org>
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^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH 1/2] i2c: s3c2410: simplify getting of_device_id match data
2021-04-15 9:38 ` Krzysztof Kozlowski
@ 2021-04-16 23:07 ` Wolfram Sang
-1 siblings, 0 replies; 8+ messages in thread
From: Wolfram Sang @ 2021-04-16 23:07 UTC (permalink / raw)
To: Krzysztof Kozlowski
Cc: linux-i2c, linux-arm-kernel, linux-samsung-soc, linux-kernel,
Marek Szyprowski, Sylwester Nawrocki, Alim Akhtar, Andrzej Hajda
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On Thu, Apr 15, 2021 at 11:38:02AM +0200, Krzysztof Kozlowski wrote:
> Use of_device_get_match_data() to make the code slightly smaller.
>
> Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Applied to for-next, thanks!
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^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH 1/2] i2c: s3c2410: simplify getting of_device_id match data
@ 2021-04-16 23:07 ` Wolfram Sang
0 siblings, 0 replies; 8+ messages in thread
From: Wolfram Sang @ 2021-04-16 23:07 UTC (permalink / raw)
To: Krzysztof Kozlowski
Cc: linux-i2c, linux-arm-kernel, linux-samsung-soc, linux-kernel,
Marek Szyprowski, Sylwester Nawrocki, Alim Akhtar, Andrzej Hajda
[-- Attachment #1.1: Type: text/plain, Size: 251 bytes --]
On Thu, Apr 15, 2021 at 11:38:02AM +0200, Krzysztof Kozlowski wrote:
> Use of_device_get_match_data() to make the code slightly smaller.
>
> Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Applied to for-next, thanks!
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^ permalink raw reply [flat|nested] 8+ messages in thread