* [PATCH 15/62] Input: synaptics-rmi4 - fix a locking bug in an error path
[not found] <20260223214950.2153735-1-bvanassche@acm.org>
@ 2026-02-23 21:49 ` Bart Van Assche
0 siblings, 0 replies; 5+ messages in thread
From: Bart Van Assche @ 2026-02-23 21:49 UTC (permalink / raw)
To: Peter Zijlstra; +Cc: Bart Van Assche, Dmitry Torokhov, Nick Dyer, linux-input
Lock f54->data_mutex before the first 'goto error' statement since
jumping to the 'error' label causes that mutex to be unlocked.
This bug has been detected by the Clang thread-safety checker.
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: Nick Dyer <nick@shmanahar.org>
Cc: linux-input@vger.kernel.org
Fixes: 3a762dbd5347 ("[media] Input: synaptics-rmi4 - add support for F54 diagnostics")
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
---
drivers/input/rmi4/rmi_f54.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/drivers/input/rmi4/rmi_f54.c b/drivers/input/rmi4/rmi_f54.c
index ac4041a69fcd..fd57ebb1cb50 100644
--- a/drivers/input/rmi4/rmi_f54.c
+++ b/drivers/input/rmi4/rmi_f54.c
@@ -539,6 +539,9 @@ static void rmi_f54_work(struct work_struct *work)
int i;
report_size = rmi_f54_get_report_size(f54);
+
+ mutex_lock(&f54->data_mutex);
+
if (report_size == 0) {
dev_err(&fn->dev, "Bad report size, report type=%d\n",
f54->report_type);
@@ -546,8 +549,6 @@ static void rmi_f54_work(struct work_struct *work)
goto error; /* retry won't help */
}
- mutex_lock(&f54->data_mutex);
-
/*
* Need to check if command has completed.
* If not try again later.
^ permalink raw reply related [flat|nested] 5+ messages in thread
* [PATCH 15/62] Input: synaptics-rmi4 - fix a locking bug in an error path
[not found] <20260223215118.2154194-1-bvanassche@acm.org>
@ 2026-02-23 21:50 ` Bart Van Assche
2026-02-23 21:58 ` Dmitry Torokhov
0 siblings, 1 reply; 5+ messages in thread
From: Bart Van Assche @ 2026-02-23 21:50 UTC (permalink / raw)
To: Peter Zijlstra
Cc: Ingo Molnar, Will Deacon, Boqun Feng, Waiman Long, linux-kernel,
Marco Elver, Christoph Hellwig, Steven Rostedt, Nick Desaulniers,
Nathan Chancellor, Kees Cook, Jann Horn, Bart Van Assche,
Dmitry Torokhov, Nick Dyer, linux-input
Lock f54->data_mutex before the first 'goto error' statement since
jumping to the 'error' label causes that mutex to be unlocked.
This bug has been detected by the Clang thread-safety checker.
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: Nick Dyer <nick@shmanahar.org>
Cc: linux-input@vger.kernel.org
Fixes: 3a762dbd5347 ("[media] Input: synaptics-rmi4 - add support for F54 diagnostics")
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
---
drivers/input/rmi4/rmi_f54.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/drivers/input/rmi4/rmi_f54.c b/drivers/input/rmi4/rmi_f54.c
index ac4041a69fcd..fd57ebb1cb50 100644
--- a/drivers/input/rmi4/rmi_f54.c
+++ b/drivers/input/rmi4/rmi_f54.c
@@ -539,6 +539,9 @@ static void rmi_f54_work(struct work_struct *work)
int i;
report_size = rmi_f54_get_report_size(f54);
+
+ mutex_lock(&f54->data_mutex);
+
if (report_size == 0) {
dev_err(&fn->dev, "Bad report size, report type=%d\n",
f54->report_type);
@@ -546,8 +549,6 @@ static void rmi_f54_work(struct work_struct *work)
goto error; /* retry won't help */
}
- mutex_lock(&f54->data_mutex);
-
/*
* Need to check if command has completed.
* If not try again later.
^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: [PATCH 15/62] Input: synaptics-rmi4 - fix a locking bug in an error path
2026-02-23 21:50 ` Bart Van Assche
@ 2026-02-23 21:58 ` Dmitry Torokhov
2026-02-23 22:05 ` Bart Van Assche
0 siblings, 1 reply; 5+ messages in thread
From: Dmitry Torokhov @ 2026-02-23 21:58 UTC (permalink / raw)
To: Bart Van Assche
Cc: Peter Zijlstra, Ingo Molnar, Will Deacon, Boqun Feng, Waiman Long,
linux-kernel, Marco Elver, Christoph Hellwig, Steven Rostedt,
Nick Desaulniers, Nathan Chancellor, Kees Cook, Jann Horn,
Nick Dyer, linux-input
Hi Bart,
On Mon, Feb 23, 2026 at 01:50:30PM -0800, Bart Van Assche wrote:
> Lock f54->data_mutex before the first 'goto error' statement since
> jumping to the 'error' label causes that mutex to be unlocked.
>
> This bug has been detected by the Clang thread-safety checker.
>
> Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
> Cc: Nick Dyer <nick@shmanahar.org>
> Cc: linux-input@vger.kernel.org
> Fixes: 3a762dbd5347 ("[media] Input: synaptics-rmi4 - add support for F54 diagnostics")
> Signed-off-by: Bart Van Assche <bvanassche@acm.org>
> ---
> drivers/input/rmi4/rmi_f54.c | 5 +++--
> 1 file changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/input/rmi4/rmi_f54.c b/drivers/input/rmi4/rmi_f54.c
> index ac4041a69fcd..fd57ebb1cb50 100644
> --- a/drivers/input/rmi4/rmi_f54.c
> +++ b/drivers/input/rmi4/rmi_f54.c
> @@ -539,6 +539,9 @@ static void rmi_f54_work(struct work_struct *work)
> int i;
>
> report_size = rmi_f54_get_report_size(f54);
> +
> + mutex_lock(&f54->data_mutex);
> +
Thank you for the patch. Do you mind if I move mutex_lock() above the
call to rmi_f54_get_report_size()? It does not extend critical section
by much, and I think logically makes more sense.
> if (report_size == 0) {
> dev_err(&fn->dev, "Bad report size, report type=%d\n",
> f54->report_type);
> @@ -546,8 +549,6 @@ static void rmi_f54_work(struct work_struct *work)
> goto error; /* retry won't help */
> }
>
> - mutex_lock(&f54->data_mutex);
> -
> /*
> * Need to check if command has completed.
> * If not try again later.
Thanks.
--
Dmitry
^ permalink raw reply [flat|nested] 5+ messages in thread
* [PATCH 15/62] Input: synaptics-rmi4 - fix a locking bug in an error path
[not found] <20260223220102.2158611-1-bart.vanassche@linux.dev>
@ 2026-02-23 22:00 ` Bart Van Assche
0 siblings, 0 replies; 5+ messages in thread
From: Bart Van Assche @ 2026-02-23 22:00 UTC (permalink / raw)
To: Peter Zijlstra
Cc: Ingo Molnar, Will Deacon, Boqun Feng, Waiman Long, linux-kernel,
Marco Elver, Christoph Hellwig, Steven Rostedt, Nick Desaulniers,
Nathan Chancellor, Kees Cook, Jann Horn, Bart Van Assche,
Dmitry Torokhov, Nick Dyer, linux-input
From: Bart Van Assche <bvanassche@acm.org>
Lock f54->data_mutex before the first 'goto error' statement since
jumping to the 'error' label causes that mutex to be unlocked.
This bug has been detected by the Clang thread-safety checker.
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: Nick Dyer <nick@shmanahar.org>
Cc: linux-input@vger.kernel.org
Fixes: 3a762dbd5347 ("[media] Input: synaptics-rmi4 - add support for F54 diagnostics")
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
---
drivers/input/rmi4/rmi_f54.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/drivers/input/rmi4/rmi_f54.c b/drivers/input/rmi4/rmi_f54.c
index ac4041a69fcd..fd57ebb1cb50 100644
--- a/drivers/input/rmi4/rmi_f54.c
+++ b/drivers/input/rmi4/rmi_f54.c
@@ -539,6 +539,9 @@ static void rmi_f54_work(struct work_struct *work)
int i;
report_size = rmi_f54_get_report_size(f54);
+
+ mutex_lock(&f54->data_mutex);
+
if (report_size == 0) {
dev_err(&fn->dev, "Bad report size, report type=%d\n",
f54->report_type);
@@ -546,8 +549,6 @@ static void rmi_f54_work(struct work_struct *work)
goto error; /* retry won't help */
}
- mutex_lock(&f54->data_mutex);
-
/*
* Need to check if command has completed.
* If not try again later.
^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: [PATCH 15/62] Input: synaptics-rmi4 - fix a locking bug in an error path
2026-02-23 21:58 ` Dmitry Torokhov
@ 2026-02-23 22:05 ` Bart Van Assche
0 siblings, 0 replies; 5+ messages in thread
From: Bart Van Assche @ 2026-02-23 22:05 UTC (permalink / raw)
To: Dmitry Torokhov
Cc: Peter Zijlstra, Ingo Molnar, Will Deacon, Boqun Feng, Waiman Long,
linux-kernel, Marco Elver, Christoph Hellwig, Steven Rostedt,
Nick Desaulniers, Nathan Chancellor, Kees Cook, Jann Horn,
Nick Dyer, linux-input
On 2/23/26 1:58 PM, Dmitry Torokhov wrote:
> Hi Bart,
>
> On Mon, Feb 23, 2026 at 01:50:30PM -0800, Bart Van Assche wrote:
>> Lock f54->data_mutex before the first 'goto error' statement since
>> jumping to the 'error' label causes that mutex to be unlocked.
>>
>> This bug has been detected by the Clang thread-safety checker.
>>
>> Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
>> Cc: Nick Dyer <nick@shmanahar.org>
>> Cc: linux-input@vger.kernel.org
>> Fixes: 3a762dbd5347 ("[media] Input: synaptics-rmi4 - add support for F54 diagnostics")
>> Signed-off-by: Bart Van Assche <bvanassche@acm.org>
>> ---
>> drivers/input/rmi4/rmi_f54.c | 5 +++--
>> 1 file changed, 3 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/input/rmi4/rmi_f54.c b/drivers/input/rmi4/rmi_f54.c
>> index ac4041a69fcd..fd57ebb1cb50 100644
>> --- a/drivers/input/rmi4/rmi_f54.c
>> +++ b/drivers/input/rmi4/rmi_f54.c
>> @@ -539,6 +539,9 @@ static void rmi_f54_work(struct work_struct *work)
>> int i;
>>
>> report_size = rmi_f54_get_report_size(f54);
>> +
>> + mutex_lock(&f54->data_mutex);
>> +
>
> Thank you for the patch. Do you mind if I move mutex_lock() above the
> call to rmi_f54_get_report_size()? It does not extend critical section
> by much, and I think logically makes more sense.
That sounds good to me. Please keep in mind that I'm not familiar with
the rmi4 driver.
Thanks,
Bart.
^ permalink raw reply [flat|nested] 5+ messages in thread
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2026-02-23 22:00 ` [PATCH 15/62] Input: synaptics-rmi4 - fix a locking bug in an error path Bart Van Assche
[not found] <20260223215118.2154194-1-bvanassche@acm.org>
2026-02-23 21:50 ` Bart Van Assche
2026-02-23 21:58 ` Dmitry Torokhov
2026-02-23 22:05 ` Bart Van Assche
[not found] <20260223214950.2153735-1-bvanassche@acm.org>
2026-02-23 21:49 ` Bart Van Assche
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