* [PATCH] coresight: Fix data argument to coresight_enable_helpers
@ 2025-09-16 22:44 Carl Worth
2025-09-17 1:35 ` Jie Gan
0 siblings, 1 reply; 9+ messages in thread
From: Carl Worth @ 2025-09-16 22:44 UTC (permalink / raw)
To: Suzuki K Poulose, Mike Leach, James Clark, Alexander Shishkin,
Sabrina Dubroca, Jie Gan
Cc: coresight, linux-arm-kernel, linux-kernel
In the commit being fixed, coresight_enable_path() was changed to call
coresight_enable_helpers() with a final argument of 'path' rather than
'sink_data'. This was invalid, resulting in derefencing a pointer to
a 'struct coresight_path' as if it were a 'struct perf_output_handle'.
The compiler could not flag the error since there are several layers
of function calls treating the pointer as void*.
Fix to correctly pass the sink_data pointer as the final argument to
coresight_enable_helpers(), exactly as it was before the buggy commit.
Bug can be reproduced with:
$ perf record -e cs_etm//k -C 0-9 dd if=/dev/zero of=/dev/null
Showing an oops as follows:
[ 88.696535] Unable to handle kernel paging request at virtual address 000f6e84934ed19e
...
[ 88.911293] Call trace:
[ 88.913728] tmc_etr_get_buffer+0x30/0x80 [coresight_tmc] (P)
[ 88.919463] catu_enable_hw+0xbc/0x3d0 [coresight_catu]
[ 88.924677] catu_enable+0x70/0xe0 [coresight_catu]
[ 88.929542] coresight_enable_path+0xb0/0x258 [coresight]
Fixes: 080ee83cc361 ("Coresight: Change functions to accept the coresight_path")
Signed-off-by: Carl Worth <carl@os.amperecomputing.com>
---
drivers/hwtracing/coresight/coresight-core.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/hwtracing/coresight/coresight-core.c b/drivers/hwtracing/coresight/coresight-core.c
index fa758cc21827..b1077d73c988 100644
--- a/drivers/hwtracing/coresight/coresight-core.c
+++ b/drivers/hwtracing/coresight/coresight-core.c
@@ -510,7 +510,7 @@ int coresight_enable_path(struct coresight_path *path, enum cs_mode mode,
type = csdev->type;
/* Enable all helpers adjacent to the path first */
- ret = coresight_enable_helpers(csdev, mode, path);
+ ret = coresight_enable_helpers(csdev, mode, sink_data);
if (ret)
goto err_disable_path;
/*
--
2.39.5
^ permalink raw reply related [flat|nested] 9+ messages in thread
* Re: [PATCH] coresight: Fix data argument to coresight_enable_helpers
2025-09-16 22:44 [PATCH] coresight: Fix data argument to coresight_enable_helpers Carl Worth
@ 2025-09-17 1:35 ` Jie Gan
2025-09-17 9:37 ` Leo Yan
2025-09-18 22:18 ` Carl Worth
0 siblings, 2 replies; 9+ messages in thread
From: Jie Gan @ 2025-09-17 1:35 UTC (permalink / raw)
To: Carl Worth, Suzuki K Poulose, Mike Leach, James Clark,
Alexander Shishkin, Sabrina Dubroca
Cc: coresight, linux-arm-kernel, linux-kernel
On 9/17/2025 6:44 AM, Carl Worth wrote:
> In the commit being fixed, coresight_enable_path() was changed to call
> coresight_enable_helpers() with a final argument of 'path' rather than
> 'sink_data'. This was invalid, resulting in derefencing a pointer to
> a 'struct coresight_path' as if it were a 'struct perf_output_handle'.
>
> The compiler could not flag the error since there are several layers
> of function calls treating the pointer as void*.
>
> Fix to correctly pass the sink_data pointer as the final argument to
> coresight_enable_helpers(), exactly as it was before the buggy commit.
>
> Bug can be reproduced with:
>
> $ perf record -e cs_etm//k -C 0-9 dd if=/dev/zero of=/dev/null
>
> Showing an oops as follows:
>
> [ 88.696535] Unable to handle kernel paging request at virtual address 000f6e84934ed19e
> ...
> [ 88.911293] Call trace:
> [ 88.913728] tmc_etr_get_buffer+0x30/0x80 [coresight_tmc] (P)
> [ 88.919463] catu_enable_hw+0xbc/0x3d0 [coresight_catu]
> [ 88.924677] catu_enable+0x70/0xe0 [coresight_catu]
> [ 88.929542] coresight_enable_path+0xb0/0x258 [coresight]
>
> Fixes: 080ee83cc361 ("Coresight: Change functions to accept the coresight_path")
> Signed-off-by: Carl Worth <carl@os.amperecomputing.com>
> ---
> drivers/hwtracing/coresight/coresight-core.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/hwtracing/coresight/coresight-core.c b/drivers/hwtracing/coresight/coresight-core.c
> index fa758cc21827..b1077d73c988 100644
> --- a/drivers/hwtracing/coresight/coresight-core.c
> +++ b/drivers/hwtracing/coresight/coresight-core.c
> @@ -510,7 +510,7 @@ int coresight_enable_path(struct coresight_path *path, enum cs_mode mode,
> type = csdev->type;
>
> /* Enable all helpers adjacent to the path first */
> - ret = coresight_enable_helpers(csdev, mode, path);
> + ret = coresight_enable_helpers(csdev, mode, sink_data);
I dont think we can change back to sink_data since we introduced
coresight_path to wrap 'data' which is needed by the path.
I suggest you to add the struct perf_output_handle to the
coresight_path, then retrieving it with data->perf_handle in
tmc_etr_get_buffer.
before:
struct perf_output_handle *handle = data;
after:
struct coresight_path *path = data;
struct perf_output_handle *handle = path->perf_handle;
We can assign the perf_output_handle to the coresight_path after we
constructed the coresight_path in perf mode.
Thanks,
Jie
> if (ret)
> goto err_disable_path;
> /*
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH] coresight: Fix data argument to coresight_enable_helpers
2025-09-17 1:35 ` Jie Gan
@ 2025-09-17 9:37 ` Leo Yan
2025-09-18 22:18 ` Carl Worth
1 sibling, 0 replies; 9+ messages in thread
From: Leo Yan @ 2025-09-17 9:37 UTC (permalink / raw)
To: Jie Gan
Cc: Carl Worth, Suzuki K Poulose, Mike Leach, James Clark,
Alexander Shishkin, Sabrina Dubroca, coresight, linux-arm-kernel,
linux-kernel
On Wed, Sep 17, 2025 at 09:35:55AM +0800, Jie Gan wrote:
[...]
> > diff --git a/drivers/hwtracing/coresight/coresight-core.c b/drivers/hwtracing/coresight/coresight-core.c
> > index fa758cc21827..b1077d73c988 100644
> > --- a/drivers/hwtracing/coresight/coresight-core.c
> > +++ b/drivers/hwtracing/coresight/coresight-core.c
> > @@ -510,7 +510,7 @@ int coresight_enable_path(struct coresight_path *path, enum cs_mode mode,
> > type = csdev->type;
> > /* Enable all helpers adjacent to the path first */
> > - ret = coresight_enable_helpers(csdev, mode, path);
> > + ret = coresight_enable_helpers(csdev, mode, sink_data);
>
> I dont think we can change back to sink_data since we introduced
> coresight_path to wrap 'data' which is needed by the path.
This change can fix catu issue but will cause regression for ctcu
driver.
> I suggest you to add the struct perf_output_handle to the coresight_path,
> then retrieving it with data->perf_handle in tmc_etr_get_buffer.
>
> before:
> struct perf_output_handle *handle = data;
>
> after:
> struct coresight_path *path = data;
> struct perf_output_handle *handle = path->perf_handle;
>
> We can assign the perf_output_handle to the coresight_path after we
> constructed the coresight_path in perf mode.
The suggestion looks good to me.
Thanks,
Leo
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH] coresight: Fix data argument to coresight_enable_helpers
2025-09-17 1:35 ` Jie Gan
2025-09-17 9:37 ` Leo Yan
@ 2025-09-18 22:18 ` Carl Worth
2025-09-19 1:20 ` Jie Gan
1 sibling, 1 reply; 9+ messages in thread
From: Carl Worth @ 2025-09-18 22:18 UTC (permalink / raw)
To: Jie Gan, Suzuki K Poulose, Mike Leach, James Clark,
Alexander Shishkin, Sabrina Dubroca
Cc: coresight, linux-arm-kernel, linux-kernel
Jie Gan <jie.gan@oss.qualcomm.com> writes:
> I dont think we can change back to sink_data since we introduced
> coresight_path to wrap 'data' which is needed by the path.
>
> I suggest you to add the struct perf_output_handle to the
> coresight_path, then retrieving it with data->perf_handle in
> tmc_etr_get_buffer.
...
> We can assign the perf_output_handle to the coresight_path after we
> constructed the coresight_path in perf mode.
Thanks. That much makes sense to me, and I'll put together a patch along
those lines.
But, further: with core coresight code assembling into the path all the
data that is necessary, is there any reason to be using void* in these
enable/disable functions?
Could we also change these functions to accept a coresight_path* and
actually get some compiler help at finding mistakes like the one we're
fixing here?
-Carl
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH] coresight: Fix data argument to coresight_enable_helpers
2025-09-18 22:18 ` Carl Worth
@ 2025-09-19 1:20 ` Jie Gan
2025-09-19 7:43 ` Suzuki K Poulose
2025-09-19 17:49 ` [PATCH v2] coresight: Fix data arguments to coresight enable/disable helpers Carl Worth
0 siblings, 2 replies; 9+ messages in thread
From: Jie Gan @ 2025-09-19 1:20 UTC (permalink / raw)
To: Carl Worth, Suzuki K Poulose, Mike Leach, James Clark,
Alexander Shishkin, Sabrina Dubroca
Cc: coresight, linux-arm-kernel, linux-kernel
On 9/19/2025 6:18 AM, Carl Worth wrote:
> Jie Gan <jie.gan@oss.qualcomm.com> writes:
>> I dont think we can change back to sink_data since we introduced
>> coresight_path to wrap 'data' which is needed by the path.
>>
>> I suggest you to add the struct perf_output_handle to the
>> coresight_path, then retrieving it with data->perf_handle in
>> tmc_etr_get_buffer.
> ...
>> We can assign the perf_output_handle to the coresight_path after we
>> constructed the coresight_path in perf mode.
>
> Thanks. That much makes sense to me, and I'll put together a patch along
> those lines.
>
> But, further: with core coresight code assembling into the path all the
> data that is necessary, is there any reason to be using void* in these
> enable/disable functions?
In my opinion, yes, we can change void * to coresight_path * for
helper's enable/disable functions since we have everything in path so
the cast is not necessary now.
>
> Could we also change these functions to accept a coresight_path* and
> actually get some compiler help at finding mistakes like the one we're
> fixing here?
That's the only benefit in my mind so far.
Thanks,
Jie
>
> -Carl
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH] coresight: Fix data argument to coresight_enable_helpers
2025-09-19 1:20 ` Jie Gan
@ 2025-09-19 7:43 ` Suzuki K Poulose
2025-09-19 20:12 ` Carl Worth
2025-09-19 17:49 ` [PATCH v2] coresight: Fix data arguments to coresight enable/disable helpers Carl Worth
1 sibling, 1 reply; 9+ messages in thread
From: Suzuki K Poulose @ 2025-09-19 7:43 UTC (permalink / raw)
To: Jie Gan, Carl Worth, Mike Leach, James Clark, Alexander Shishkin,
Sabrina Dubroca
Cc: coresight, linux-arm-kernel, linux-kernel
On 19/09/2025 02:20, Jie Gan wrote:
>
>
> On 9/19/2025 6:18 AM, Carl Worth wrote:
>> Jie Gan <jie.gan@oss.qualcomm.com> writes:
>>> I dont think we can change back to sink_data since we introduced
>>> coresight_path to wrap 'data' which is needed by the path.
>>>
>>> I suggest you to add the struct perf_output_handle to the
>>> coresight_path, then retrieving it with data->perf_handle in
>>> tmc_etr_get_buffer.
>> ...
>>> We can assign the perf_output_handle to the coresight_path after we
>>> constructed the coresight_path in perf mode.
>>
>> Thanks. That much makes sense to me, and I'll put together a patch along
>> those lines.
>>
>> But, further: with core coresight code assembling into the path all the
>> data that is necessary, is there any reason to be using void* in these
>> enable/disable functions?
>
> In my opinion, yes, we can change void * to coresight_path * for
> helper's enable/disable functions since we have everything in path so
> the cast is not necessary now.
>
>>
>> Could we also change these functions to accept a coresight_path* and
>> actually get some compiler help at finding mistakes like the one we're
>> fixing here?
>
Yes, please. I was going to suggest that. May be we could do that as
a separate patch after fixing the problem here first (so that it
can be back ported).
This was initially a perf_handle only used for the perf mode, and
it didn't make sens to have a "perf" argument to "enable" which
could be used for both sysfs and perf. Now that the path
is a generic data structure, it makes sense to move everything
to accept the path.
Suzuki
> That's the only benefit in my mind so far.
>
> Thanks,
> Jie
>
>>
>> -Carl
>
^ permalink raw reply [flat|nested] 9+ messages in thread
* [PATCH v2] coresight: Fix data arguments to coresight enable/disable helpers
2025-09-19 1:20 ` Jie Gan
2025-09-19 7:43 ` Suzuki K Poulose
@ 2025-09-19 17:49 ` Carl Worth
2025-09-20 1:36 ` Jie Gan
1 sibling, 1 reply; 9+ messages in thread
From: Carl Worth @ 2025-09-19 17:49 UTC (permalink / raw)
To: Suzuki K Poulose, Mike Leach, James Clark, Alexander Shishkin,
Sabrina Dubroca, Jie Gan
Cc: coresight, linux-arm-kernel, linux-kernel
In the commit being fixed, coresight_enable_path() was changed to call
coresight_enable_helpers() by passing a struct coresight_path*
as the final void* 'path' argument, rather passing 'sink_data'
as was being passed previously. This set the groundwork for the
subsequent addition of the ctcu_enable function which interprets
void* data as a struct coresight_path*, but it also broke the
existing catu_enable function which interprets void* data
as a struct perf_output_handle*.
The compiler could not flag the error since there are several layers
of function calls treating the pointer as void*.
Fix both users simultaneously by adding an additional argument to the
enable helper interface. So now both the struct coresight_path and the
struct perf_output_handle pointers are passed. Also, eliminate all
usages of the void* from these code paths and use explicit types
instead to make all of this code more robust.
Note: The disable function is also changed from void* to
struct coresight_path* but no implementations of this function
need the struct perf_output_handle* so it is not added to the interface.
The existing bug can be reproduced with:
# perf record -e cs_etm//k -C 0-9 dd if=/dev/zero of=/dev/null
Showing an oops as follows:
Unable to handle kernel paging request at virtual address 000f6e84934ed19e
Call trace:
tmc_etr_get_buffer+0x30/0x80 [coresight_tmc] (P)
catu_enable_hw+0xbc/0x3d0 [coresight_catu]
catu_enable+0x70/0xe0 [coresight_catu]
coresight_enable_path+0xb0/0x258 [coresight]
Fixes: 080ee83cc361 ("Coresight: Change functions to accept the coresight_path")
Signed-off-by: Carl Worth <carl@os.amperecomputing.com>
---
Jie, I looked into your suggestion of adding the struct
perf_output_handle* to the struct coresight_path, but I couldn't
justify adding event-related data to the path structure, which has
nothing to do with it.
So, instead I took the approach in this patch to plumb both arguments
through the enable path, (and changed away from void* as you agreed
to).
Note: I've tested that this fixes the bug for catu_enable. This patch
also obviously touches ctcu_enable, which I believe is correct, but I
have not tested since I don't have ready access to the necessary
hardware. I will appreciate other testing.
-Carl
drivers/hwtracing/coresight/coresight-catu.c | 12 ++++++----
drivers/hwtracing/coresight/coresight-core.c | 23 +++++++++++--------
.../hwtracing/coresight/coresight-ctcu-core.c | 11 ++++-----
.../hwtracing/coresight/coresight-cti-core.c | 7 ++++--
.../hwtracing/coresight/coresight-cti-sysfs.c | 2 +-
drivers/hwtracing/coresight/coresight-cti.h | 6 +++--
drivers/hwtracing/coresight/coresight-priv.h | 2 +-
.../hwtracing/coresight/coresight-tmc-etr.c | 4 ++--
drivers/hwtracing/coresight/coresight-tmc.h | 3 ++-
include/linux/coresight.h | 6 +++--
10 files changed, 45 insertions(+), 31 deletions(-)
diff --git a/drivers/hwtracing/coresight/coresight-catu.c b/drivers/hwtracing/coresight/coresight-catu.c
index 5058432233da..724c25d0afa4 100644
--- a/drivers/hwtracing/coresight/coresight-catu.c
+++ b/drivers/hwtracing/coresight/coresight-catu.c
@@ -397,7 +397,7 @@ static int catu_wait_for_ready(struct catu_drvdata *drvdata)
}
static int catu_enable_hw(struct catu_drvdata *drvdata, enum cs_mode cs_mode,
- void *data)
+ struct perf_output_handle *handle)
{
int rc;
u32 control, mode;
@@ -425,7 +425,7 @@ static int catu_enable_hw(struct catu_drvdata *drvdata, enum cs_mode cs_mode,
etrdev = coresight_find_input_type(
csdev->pdata, CORESIGHT_DEV_TYPE_SINK, etr_subtype);
if (etrdev) {
- etr_buf = tmc_etr_get_buffer(etrdev, cs_mode, data);
+ etr_buf = tmc_etr_get_buffer(etrdev, cs_mode, handle);
if (IS_ERR(etr_buf))
return PTR_ERR(etr_buf);
}
@@ -455,7 +455,8 @@ static int catu_enable_hw(struct catu_drvdata *drvdata, enum cs_mode cs_mode,
}
static int catu_enable(struct coresight_device *csdev, enum cs_mode mode,
- void *data)
+ struct coresight_path *path,
+ struct perf_output_handle *handle)
{
int rc = 0;
struct catu_drvdata *catu_drvdata = csdev_to_catu_drvdata(csdev);
@@ -463,7 +464,7 @@ static int catu_enable(struct coresight_device *csdev, enum cs_mode mode,
guard(raw_spinlock_irqsave)(&catu_drvdata->spinlock);
if (csdev->refcnt == 0) {
CS_UNLOCK(catu_drvdata->base);
- rc = catu_enable_hw(catu_drvdata, mode, data);
+ rc = catu_enable_hw(catu_drvdata, mode, handle);
CS_LOCK(catu_drvdata->base);
}
if (!rc)
@@ -488,7 +489,8 @@ static int catu_disable_hw(struct catu_drvdata *drvdata)
return rc;
}
-static int catu_disable(struct coresight_device *csdev, void *__unused)
+static int catu_disable(struct coresight_device *csdev,
+ struct coresight_path *__unused)
{
int rc = 0;
struct catu_drvdata *catu_drvdata = csdev_to_catu_drvdata(csdev);
diff --git a/drivers/hwtracing/coresight/coresight-core.c b/drivers/hwtracing/coresight/coresight-core.c
index fa758cc21827..cc449d5196a4 100644
--- a/drivers/hwtracing/coresight/coresight-core.c
+++ b/drivers/hwtracing/coresight/coresight-core.c
@@ -353,14 +353,17 @@ static bool coresight_is_helper(struct coresight_device *csdev)
}
static int coresight_enable_helper(struct coresight_device *csdev,
- enum cs_mode mode, void *data)
+ enum cs_mode mode,
+ struct coresight_path *path,
+ struct perf_output_handle *handle)
{
- return helper_ops(csdev)->enable(csdev, mode, data);
+ return helper_ops(csdev)->enable(csdev, mode, path, handle);
}
-static void coresight_disable_helper(struct coresight_device *csdev, void *data)
+static void coresight_disable_helper(struct coresight_device *csdev,
+ struct coresight_path *path)
{
- helper_ops(csdev)->disable(csdev, data);
+ helper_ops(csdev)->disable(csdev, path);
}
static void coresight_disable_helpers(struct coresight_device *csdev, void *data)
@@ -477,7 +480,9 @@ void coresight_disable_path(struct coresight_path *path)
EXPORT_SYMBOL_GPL(coresight_disable_path);
static int coresight_enable_helpers(struct coresight_device *csdev,
- enum cs_mode mode, void *data)
+ enum cs_mode mode,
+ struct coresight_path *path,
+ struct perf_output_handle *handle)
{
int i, ret = 0;
struct coresight_device *helper;
@@ -487,7 +492,7 @@ static int coresight_enable_helpers(struct coresight_device *csdev,
if (!helper || !coresight_is_helper(helper))
continue;
- ret = coresight_enable_helper(helper, mode, data);
+ ret = coresight_enable_helper(helper, mode, path, handle);
if (ret)
return ret;
}
@@ -496,7 +501,7 @@ static int coresight_enable_helpers(struct coresight_device *csdev,
}
int coresight_enable_path(struct coresight_path *path, enum cs_mode mode,
- void *sink_data)
+ struct perf_output_handle *handle)
{
int ret = 0;
u32 type;
@@ -510,7 +515,7 @@ int coresight_enable_path(struct coresight_path *path, enum cs_mode mode,
type = csdev->type;
/* Enable all helpers adjacent to the path first */
- ret = coresight_enable_helpers(csdev, mode, path);
+ ret = coresight_enable_helpers(csdev, mode, path, handle);
if (ret)
goto err_disable_path;
/*
@@ -526,7 +531,7 @@ int coresight_enable_path(struct coresight_path *path, enum cs_mode mode,
switch (type) {
case CORESIGHT_DEV_TYPE_SINK:
- ret = coresight_enable_sink(csdev, mode, sink_data);
+ ret = coresight_enable_sink(csdev, mode, handle);
/*
* Sink is the first component turned on. If we
* failed to enable the sink, there are no components
diff --git a/drivers/hwtracing/coresight/coresight-ctcu-core.c b/drivers/hwtracing/coresight/coresight-ctcu-core.c
index c6bafc96db96..9f6d71c59d4e 100644
--- a/drivers/hwtracing/coresight/coresight-ctcu-core.c
+++ b/drivers/hwtracing/coresight/coresight-ctcu-core.c
@@ -156,17 +156,16 @@ static int ctcu_set_etr_traceid(struct coresight_device *csdev, struct coresight
return __ctcu_set_etr_traceid(csdev, traceid, port_num, enable);
}
-static int ctcu_enable(struct coresight_device *csdev, enum cs_mode mode, void *data)
+static int ctcu_enable(struct coresight_device *csdev, enum cs_mode mode,
+ struct coresight_path *path,
+ struct perf_output_handle *handle)
{
- struct coresight_path *path = (struct coresight_path *)data;
-
return ctcu_set_etr_traceid(csdev, path, true);
}
-static int ctcu_disable(struct coresight_device *csdev, void *data)
+static int ctcu_disable(struct coresight_device *csdev,
+ struct coresight_path *path)
{
- struct coresight_path *path = (struct coresight_path *)data;
-
return ctcu_set_etr_traceid(csdev, path, false);
}
diff --git a/drivers/hwtracing/coresight/coresight-cti-core.c b/drivers/hwtracing/coresight/coresight-cti-core.c
index 8fb30dd73fd2..f92e3be4607c 100644
--- a/drivers/hwtracing/coresight/coresight-cti-core.c
+++ b/drivers/hwtracing/coresight/coresight-cti-core.c
@@ -799,14 +799,17 @@ static void cti_pm_release(struct cti_drvdata *drvdata)
}
/** cti ect operations **/
-int cti_enable(struct coresight_device *csdev, enum cs_mode mode, void *data)
+int cti_enable(struct coresight_device *csdev, enum cs_mode mode,
+ struct coresight_path *path,
+ struct perf_output_handle *handle)
{
struct cti_drvdata *drvdata = csdev_to_cti_drvdata(csdev);
return cti_enable_hw(drvdata);
}
-int cti_disable(struct coresight_device *csdev, void *data)
+int cti_disable(struct coresight_device *csdev,
+ struct coresight_path *path)
{
struct cti_drvdata *drvdata = csdev_to_cti_drvdata(csdev);
diff --git a/drivers/hwtracing/coresight/coresight-cti-sysfs.c b/drivers/hwtracing/coresight/coresight-cti-sysfs.c
index 572b80ee96fb..2bb6929eeb19 100644
--- a/drivers/hwtracing/coresight/coresight-cti-sysfs.c
+++ b/drivers/hwtracing/coresight/coresight-cti-sysfs.c
@@ -112,7 +112,7 @@ static ssize_t enable_store(struct device *dev,
ret = pm_runtime_resume_and_get(dev->parent);
if (ret)
return ret;
- ret = cti_enable(drvdata->csdev, CS_MODE_SYSFS, NULL);
+ ret = cti_enable(drvdata->csdev, CS_MODE_SYSFS, NULL, NULL);
if (ret)
pm_runtime_put(dev->parent);
} else {
diff --git a/drivers/hwtracing/coresight/coresight-cti.h b/drivers/hwtracing/coresight/coresight-cti.h
index 8362a47c939c..73954369654c 100644
--- a/drivers/hwtracing/coresight/coresight-cti.h
+++ b/drivers/hwtracing/coresight/coresight-cti.h
@@ -216,8 +216,10 @@ int cti_add_connection_entry(struct device *dev, struct cti_drvdata *drvdata,
const char *assoc_dev_name);
struct cti_trig_con *cti_allocate_trig_con(struct device *dev, int in_sigs,
int out_sigs);
-int cti_enable(struct coresight_device *csdev, enum cs_mode mode, void *data);
-int cti_disable(struct coresight_device *csdev, void *data);
+int cti_enable(struct coresight_device *csdev, enum cs_mode mode,
+ struct coresight_path *path,
+ struct perf_output_handle *handle);
+int cti_disable(struct coresight_device *csdev, struct coresight_path *path);
void cti_write_all_hw_regs(struct cti_drvdata *drvdata);
void cti_write_intack(struct device *dev, u32 ackval);
void cti_write_single_reg(struct cti_drvdata *drvdata, int offset, u32 value);
diff --git a/drivers/hwtracing/coresight/coresight-priv.h b/drivers/hwtracing/coresight/coresight-priv.h
index 33e22b1ba043..65c4984d98c0 100644
--- a/drivers/hwtracing/coresight/coresight-priv.h
+++ b/drivers/hwtracing/coresight/coresight-priv.h
@@ -136,7 +136,7 @@ static inline void CS_UNLOCK(void __iomem *addr)
void coresight_disable_path(struct coresight_path *path);
int coresight_enable_path(struct coresight_path *path, enum cs_mode mode,
- void *sink_data);
+ struct perf_output_handle *handle);
struct coresight_device *coresight_get_sink(struct coresight_path *path);
struct coresight_device *coresight_get_sink_by_id(u32 id);
struct coresight_device *
diff --git a/drivers/hwtracing/coresight/coresight-tmc-etr.c b/drivers/hwtracing/coresight/coresight-tmc-etr.c
index b07fcdb3fe1a..2ed7fa2366ce 100644
--- a/drivers/hwtracing/coresight/coresight-tmc-etr.c
+++ b/drivers/hwtracing/coresight/coresight-tmc-etr.c
@@ -1325,9 +1325,9 @@ static int tmc_enable_etr_sink_sysfs(struct coresight_device *csdev)
}
struct etr_buf *tmc_etr_get_buffer(struct coresight_device *csdev,
- enum cs_mode mode, void *data)
+ enum cs_mode mode,
+ struct perf_output_handle *handle)
{
- struct perf_output_handle *handle = data;
struct etr_perf_buffer *etr_perf;
switch (mode) {
diff --git a/drivers/hwtracing/coresight/coresight-tmc.h b/drivers/hwtracing/coresight/coresight-tmc.h
index 6541a27a018e..b6e2b00d393a 100644
--- a/drivers/hwtracing/coresight/coresight-tmc.h
+++ b/drivers/hwtracing/coresight/coresight-tmc.h
@@ -440,7 +440,8 @@ struct coresight_device *tmc_etr_get_catu_device(struct tmc_drvdata *drvdata);
void tmc_etr_set_catu_ops(const struct etr_buf_operations *catu);
void tmc_etr_remove_catu_ops(void);
struct etr_buf *tmc_etr_get_buffer(struct coresight_device *csdev,
- enum cs_mode mode, void *data);
+ enum cs_mode mode,
+ struct perf_output_handle *handle);
extern const struct attribute_group coresight_etr_group;
#endif
diff --git a/include/linux/coresight.h b/include/linux/coresight.h
index 4ac65c68bbf4..450cccd46f38 100644
--- a/include/linux/coresight.h
+++ b/include/linux/coresight.h
@@ -422,8 +422,10 @@ struct coresight_ops_source {
*/
struct coresight_ops_helper {
int (*enable)(struct coresight_device *csdev, enum cs_mode mode,
- void *data);
- int (*disable)(struct coresight_device *csdev, void *data);
+ struct coresight_path *path,
+ struct perf_output_handle *data);
+ int (*disable)(struct coresight_device *csdev,
+ struct coresight_path *path);
};
base-commit: 46a51f4f5edade43ba66b3c151f0e25ec8b69cb6
--
2.39.5
^ permalink raw reply related [flat|nested] 9+ messages in thread
* Re: [PATCH] coresight: Fix data argument to coresight_enable_helpers
2025-09-19 7:43 ` Suzuki K Poulose
@ 2025-09-19 20:12 ` Carl Worth
0 siblings, 0 replies; 9+ messages in thread
From: Carl Worth @ 2025-09-19 20:12 UTC (permalink / raw)
To: Suzuki K Poulose, Jie Gan, Mike Leach, James Clark,
Alexander Shishkin, Sabrina Dubroca
Cc: coresight, linux-arm-kernel, linux-kernel
Suzuki K Poulose <suzuki.poulose@arm.com> writes:
> Yes, please. I was going to suggest that. May be we could do that as
> a separate patch after fixing the problem here first (so that it
> can be back ported).
Hi, Suzuki,
I saw this suggestion after I had put together my v2 version of the
patch, where I split the path and handle into separate arguments and
also got rid of void* in a single patch. With that approach I think it
only makes sense to do them together.
But if we instead were to make everything work with a single path
argument, then I agree it would have made sense to change the type in a
separate patch.
> This was initially a perf_handle only used for the perf mode, and
> it didn't make sens to have a "perf" argument to "enable" which
> could be used for both sysfs and perf. Now that the path
> is a generic data structure, it makes sense to move everything
> to accept the path.
I'm fairly new to the entire coresight subsystem, so I might be getting
this wrong. It looks to me like the perf handle is really part of the
event so wouldn't logically make sense as part of the path? Am I
understanding that correctly?
-Carl
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH v2] coresight: Fix data arguments to coresight enable/disable helpers
2025-09-19 17:49 ` [PATCH v2] coresight: Fix data arguments to coresight enable/disable helpers Carl Worth
@ 2025-09-20 1:36 ` Jie Gan
0 siblings, 0 replies; 9+ messages in thread
From: Jie Gan @ 2025-09-20 1:36 UTC (permalink / raw)
To: Carl Worth, Suzuki K Poulose, Mike Leach, James Clark,
Alexander Shishkin, Sabrina Dubroca, Jie Gan
Cc: coresight, linux-arm-kernel, linux-kernel
On 9/20/2025 1:49 AM, Carl Worth wrote:
> In the commit being fixed, coresight_enable_path() was changed to call
> coresight_enable_helpers() by passing a struct coresight_path*
> as the final void* 'path' argument, rather passing 'sink_data'
> as was being passed previously. This set the groundwork for the
> subsequent addition of the ctcu_enable function which interprets
> void* data as a struct coresight_path*, but it also broke the
> existing catu_enable function which interprets void* data
> as a struct perf_output_handle*.
>
> The compiler could not flag the error since there are several layers
> of function calls treating the pointer as void*.
>
> Fix both users simultaneously by adding an additional argument to the
> enable helper interface. So now both the struct coresight_path and the
> struct perf_output_handle pointers are passed. Also, eliminate all
> usages of the void* from these code paths and use explicit types
> instead to make all of this code more robust.
>
> Note: The disable function is also changed from void* to
> struct coresight_path* but no implementations of this function
> need the struct perf_output_handle* so it is not added to the interface.
>
> The existing bug can be reproduced with:
>
> # perf record -e cs_etm//k -C 0-9 dd if=/dev/zero of=/dev/null
>
> Showing an oops as follows:
>
> Unable to handle kernel paging request at virtual address 000f6e84934ed19e
>
> Call trace:
> tmc_etr_get_buffer+0x30/0x80 [coresight_tmc] (P)
> catu_enable_hw+0xbc/0x3d0 [coresight_catu]
> catu_enable+0x70/0xe0 [coresight_catu]
> coresight_enable_path+0xb0/0x258 [coresight]
>
> Fixes: 080ee83cc361 ("Coresight: Change functions to accept the coresight_path")
> Signed-off-by: Carl Worth <carl@os.amperecomputing.com>
> ---
>
> Jie, I looked into your suggestion of adding the struct
> perf_output_handle* to the struct coresight_path, but I couldn't
> justify adding event-related data to the path structure, which has
> nothing to do with it.
The AUX event only available in perf mode. Each subsystem can access it
from the path if needed. Since the Coresight system operates by
constructing a path — and this path is passed to each device as data -
it’s acceptable to include all relevant parameters in the
coresight_path, provided the devices along the path require them.
Do you want me to create a patch as example?
Thanks,
Jie
>
> So, instead I took the approach in this patch to plumb both arguments
> through the enable path, (and changed away from void* as you agreed
> to).
>
> Note: I've tested that this fixes the bug for catu_enable. This patch
> also obviously touches ctcu_enable, which I believe is correct, but I
> have not tested since I don't have ready access to the necessary
> hardware. I will appreciate other testing.
>
> -Carl
>
> drivers/hwtracing/coresight/coresight-catu.c | 12 ++++++----
> drivers/hwtracing/coresight/coresight-core.c | 23 +++++++++++--------
> .../hwtracing/coresight/coresight-ctcu-core.c | 11 ++++-----
> .../hwtracing/coresight/coresight-cti-core.c | 7 ++++--
> .../hwtracing/coresight/coresight-cti-sysfs.c | 2 +-
> drivers/hwtracing/coresight/coresight-cti.h | 6 +++--
> drivers/hwtracing/coresight/coresight-priv.h | 2 +-
> .../hwtracing/coresight/coresight-tmc-etr.c | 4 ++--
> drivers/hwtracing/coresight/coresight-tmc.h | 3 ++-
> include/linux/coresight.h | 6 +++--
> 10 files changed, 45 insertions(+), 31 deletions(-)
>
> diff --git a/drivers/hwtracing/coresight/coresight-catu.c b/drivers/hwtracing/coresight/coresight-catu.c
> index 5058432233da..724c25d0afa4 100644
> --- a/drivers/hwtracing/coresight/coresight-catu.c
> +++ b/drivers/hwtracing/coresight/coresight-catu.c
> @@ -397,7 +397,7 @@ static int catu_wait_for_ready(struct catu_drvdata *drvdata)
> }
>
> static int catu_enable_hw(struct catu_drvdata *drvdata, enum cs_mode cs_mode,
> - void *data)
> + struct perf_output_handle *handle)
> {
> int rc;
> u32 control, mode;
> @@ -425,7 +425,7 @@ static int catu_enable_hw(struct catu_drvdata *drvdata, enum cs_mode cs_mode,
> etrdev = coresight_find_input_type(
> csdev->pdata, CORESIGHT_DEV_TYPE_SINK, etr_subtype);
> if (etrdev) {
> - etr_buf = tmc_etr_get_buffer(etrdev, cs_mode, data);
> + etr_buf = tmc_etr_get_buffer(etrdev, cs_mode, handle);
> if (IS_ERR(etr_buf))
> return PTR_ERR(etr_buf);
> }
> @@ -455,7 +455,8 @@ static int catu_enable_hw(struct catu_drvdata *drvdata, enum cs_mode cs_mode,
> }
>
> static int catu_enable(struct coresight_device *csdev, enum cs_mode mode,
> - void *data)
> + struct coresight_path *path,
> + struct perf_output_handle *handle)
> {
> int rc = 0;
> struct catu_drvdata *catu_drvdata = csdev_to_catu_drvdata(csdev);
> @@ -463,7 +464,7 @@ static int catu_enable(struct coresight_device *csdev, enum cs_mode mode,
> guard(raw_spinlock_irqsave)(&catu_drvdata->spinlock);
> if (csdev->refcnt == 0) {
> CS_UNLOCK(catu_drvdata->base);
> - rc = catu_enable_hw(catu_drvdata, mode, data);
> + rc = catu_enable_hw(catu_drvdata, mode, handle);
> CS_LOCK(catu_drvdata->base);
> }
> if (!rc)
> @@ -488,7 +489,8 @@ static int catu_disable_hw(struct catu_drvdata *drvdata)
> return rc;
> }
>
> -static int catu_disable(struct coresight_device *csdev, void *__unused)
> +static int catu_disable(struct coresight_device *csdev,
> + struct coresight_path *__unused)
> {
> int rc = 0;
> struct catu_drvdata *catu_drvdata = csdev_to_catu_drvdata(csdev);
> diff --git a/drivers/hwtracing/coresight/coresight-core.c b/drivers/hwtracing/coresight/coresight-core.c
> index fa758cc21827..cc449d5196a4 100644
> --- a/drivers/hwtracing/coresight/coresight-core.c
> +++ b/drivers/hwtracing/coresight/coresight-core.c
> @@ -353,14 +353,17 @@ static bool coresight_is_helper(struct coresight_device *csdev)
> }
>
> static int coresight_enable_helper(struct coresight_device *csdev,
> - enum cs_mode mode, void *data)
> + enum cs_mode mode,
> + struct coresight_path *path,
> + struct perf_output_handle *handle)
> {
> - return helper_ops(csdev)->enable(csdev, mode, data);
> + return helper_ops(csdev)->enable(csdev, mode, path, handle);
> }
>
> -static void coresight_disable_helper(struct coresight_device *csdev, void *data)
> +static void coresight_disable_helper(struct coresight_device *csdev,
> + struct coresight_path *path)
> {
> - helper_ops(csdev)->disable(csdev, data);
> + helper_ops(csdev)->disable(csdev, path);
> }
>
> static void coresight_disable_helpers(struct coresight_device *csdev, void *data)
> @@ -477,7 +480,9 @@ void coresight_disable_path(struct coresight_path *path)
> EXPORT_SYMBOL_GPL(coresight_disable_path);
>
> static int coresight_enable_helpers(struct coresight_device *csdev,
> - enum cs_mode mode, void *data)
> + enum cs_mode mode,
> + struct coresight_path *path,
> + struct perf_output_handle *handle)
> {
> int i, ret = 0;
> struct coresight_device *helper;
> @@ -487,7 +492,7 @@ static int coresight_enable_helpers(struct coresight_device *csdev,
> if (!helper || !coresight_is_helper(helper))
> continue;
>
> - ret = coresight_enable_helper(helper, mode, data);
> + ret = coresight_enable_helper(helper, mode, path, handle);
> if (ret)
> return ret;
> }
> @@ -496,7 +501,7 @@ static int coresight_enable_helpers(struct coresight_device *csdev,
> }
>
> int coresight_enable_path(struct coresight_path *path, enum cs_mode mode,
> - void *sink_data)
> + struct perf_output_handle *handle)
> {
> int ret = 0;
> u32 type;
> @@ -510,7 +515,7 @@ int coresight_enable_path(struct coresight_path *path, enum cs_mode mode,
> type = csdev->type;
>
> /* Enable all helpers adjacent to the path first */
> - ret = coresight_enable_helpers(csdev, mode, path);
> + ret = coresight_enable_helpers(csdev, mode, path, handle);
> if (ret)
> goto err_disable_path;
> /*
> @@ -526,7 +531,7 @@ int coresight_enable_path(struct coresight_path *path, enum cs_mode mode,
>
> switch (type) {
> case CORESIGHT_DEV_TYPE_SINK:
> - ret = coresight_enable_sink(csdev, mode, sink_data);
> + ret = coresight_enable_sink(csdev, mode, handle);
> /*
> * Sink is the first component turned on. If we
> * failed to enable the sink, there are no components
> diff --git a/drivers/hwtracing/coresight/coresight-ctcu-core.c b/drivers/hwtracing/coresight/coresight-ctcu-core.c
> index c6bafc96db96..9f6d71c59d4e 100644
> --- a/drivers/hwtracing/coresight/coresight-ctcu-core.c
> +++ b/drivers/hwtracing/coresight/coresight-ctcu-core.c
> @@ -156,17 +156,16 @@ static int ctcu_set_etr_traceid(struct coresight_device *csdev, struct coresight
> return __ctcu_set_etr_traceid(csdev, traceid, port_num, enable);
> }
>
> -static int ctcu_enable(struct coresight_device *csdev, enum cs_mode mode, void *data)
> +static int ctcu_enable(struct coresight_device *csdev, enum cs_mode mode,
> + struct coresight_path *path,
> + struct perf_output_handle *handle)
> {
> - struct coresight_path *path = (struct coresight_path *)data;
> -
> return ctcu_set_etr_traceid(csdev, path, true);
> }
>
> -static int ctcu_disable(struct coresight_device *csdev, void *data)
> +static int ctcu_disable(struct coresight_device *csdev,
> + struct coresight_path *path)
> {
> - struct coresight_path *path = (struct coresight_path *)data;
> -
> return ctcu_set_etr_traceid(csdev, path, false);
> }
>
> diff --git a/drivers/hwtracing/coresight/coresight-cti-core.c b/drivers/hwtracing/coresight/coresight-cti-core.c
> index 8fb30dd73fd2..f92e3be4607c 100644
> --- a/drivers/hwtracing/coresight/coresight-cti-core.c
> +++ b/drivers/hwtracing/coresight/coresight-cti-core.c
> @@ -799,14 +799,17 @@ static void cti_pm_release(struct cti_drvdata *drvdata)
> }
>
> /** cti ect operations **/
> -int cti_enable(struct coresight_device *csdev, enum cs_mode mode, void *data)
> +int cti_enable(struct coresight_device *csdev, enum cs_mode mode,
> + struct coresight_path *path,
> + struct perf_output_handle *handle)
> {
> struct cti_drvdata *drvdata = csdev_to_cti_drvdata(csdev);
>
> return cti_enable_hw(drvdata);
> }
>
> -int cti_disable(struct coresight_device *csdev, void *data)
> +int cti_disable(struct coresight_device *csdev,
> + struct coresight_path *path)
> {
> struct cti_drvdata *drvdata = csdev_to_cti_drvdata(csdev);
>
> diff --git a/drivers/hwtracing/coresight/coresight-cti-sysfs.c b/drivers/hwtracing/coresight/coresight-cti-sysfs.c
> index 572b80ee96fb..2bb6929eeb19 100644
> --- a/drivers/hwtracing/coresight/coresight-cti-sysfs.c
> +++ b/drivers/hwtracing/coresight/coresight-cti-sysfs.c
> @@ -112,7 +112,7 @@ static ssize_t enable_store(struct device *dev,
> ret = pm_runtime_resume_and_get(dev->parent);
> if (ret)
> return ret;
> - ret = cti_enable(drvdata->csdev, CS_MODE_SYSFS, NULL);
> + ret = cti_enable(drvdata->csdev, CS_MODE_SYSFS, NULL, NULL);
> if (ret)
> pm_runtime_put(dev->parent);
> } else {
> diff --git a/drivers/hwtracing/coresight/coresight-cti.h b/drivers/hwtracing/coresight/coresight-cti.h
> index 8362a47c939c..73954369654c 100644
> --- a/drivers/hwtracing/coresight/coresight-cti.h
> +++ b/drivers/hwtracing/coresight/coresight-cti.h
> @@ -216,8 +216,10 @@ int cti_add_connection_entry(struct device *dev, struct cti_drvdata *drvdata,
> const char *assoc_dev_name);
> struct cti_trig_con *cti_allocate_trig_con(struct device *dev, int in_sigs,
> int out_sigs);
> -int cti_enable(struct coresight_device *csdev, enum cs_mode mode, void *data);
> -int cti_disable(struct coresight_device *csdev, void *data);
> +int cti_enable(struct coresight_device *csdev, enum cs_mode mode,
> + struct coresight_path *path,
> + struct perf_output_handle *handle);
> +int cti_disable(struct coresight_device *csdev, struct coresight_path *path);
> void cti_write_all_hw_regs(struct cti_drvdata *drvdata);
> void cti_write_intack(struct device *dev, u32 ackval);
> void cti_write_single_reg(struct cti_drvdata *drvdata, int offset, u32 value);
> diff --git a/drivers/hwtracing/coresight/coresight-priv.h b/drivers/hwtracing/coresight/coresight-priv.h
> index 33e22b1ba043..65c4984d98c0 100644
> --- a/drivers/hwtracing/coresight/coresight-priv.h
> +++ b/drivers/hwtracing/coresight/coresight-priv.h
> @@ -136,7 +136,7 @@ static inline void CS_UNLOCK(void __iomem *addr)
>
> void coresight_disable_path(struct coresight_path *path);
> int coresight_enable_path(struct coresight_path *path, enum cs_mode mode,
> - void *sink_data);
> + struct perf_output_handle *handle);
> struct coresight_device *coresight_get_sink(struct coresight_path *path);
> struct coresight_device *coresight_get_sink_by_id(u32 id);
> struct coresight_device *
> diff --git a/drivers/hwtracing/coresight/coresight-tmc-etr.c b/drivers/hwtracing/coresight/coresight-tmc-etr.c
> index b07fcdb3fe1a..2ed7fa2366ce 100644
> --- a/drivers/hwtracing/coresight/coresight-tmc-etr.c
> +++ b/drivers/hwtracing/coresight/coresight-tmc-etr.c
> @@ -1325,9 +1325,9 @@ static int tmc_enable_etr_sink_sysfs(struct coresight_device *csdev)
> }
>
> struct etr_buf *tmc_etr_get_buffer(struct coresight_device *csdev,
> - enum cs_mode mode, void *data)
> + enum cs_mode mode,
> + struct perf_output_handle *handle)
> {
> - struct perf_output_handle *handle = data;
> struct etr_perf_buffer *etr_perf;
>
> switch (mode) {
> diff --git a/drivers/hwtracing/coresight/coresight-tmc.h b/drivers/hwtracing/coresight/coresight-tmc.h
> index 6541a27a018e..b6e2b00d393a 100644
> --- a/drivers/hwtracing/coresight/coresight-tmc.h
> +++ b/drivers/hwtracing/coresight/coresight-tmc.h
> @@ -440,7 +440,8 @@ struct coresight_device *tmc_etr_get_catu_device(struct tmc_drvdata *drvdata);
> void tmc_etr_set_catu_ops(const struct etr_buf_operations *catu);
> void tmc_etr_remove_catu_ops(void);
> struct etr_buf *tmc_etr_get_buffer(struct coresight_device *csdev,
> - enum cs_mode mode, void *data);
> + enum cs_mode mode,
> + struct perf_output_handle *handle);
> extern const struct attribute_group coresight_etr_group;
>
> #endif
> diff --git a/include/linux/coresight.h b/include/linux/coresight.h
> index 4ac65c68bbf4..450cccd46f38 100644
> --- a/include/linux/coresight.h
> +++ b/include/linux/coresight.h
> @@ -422,8 +422,10 @@ struct coresight_ops_source {
> */
> struct coresight_ops_helper {
> int (*enable)(struct coresight_device *csdev, enum cs_mode mode,
> - void *data);
> - int (*disable)(struct coresight_device *csdev, void *data);
> + struct coresight_path *path,
> + struct perf_output_handle *data);
> + int (*disable)(struct coresight_device *csdev,
> + struct coresight_path *path);
> };
>
>
>
> base-commit: 46a51f4f5edade43ba66b3c151f0e25ec8b69cb6
^ permalink raw reply [flat|nested] 9+ messages in thread
end of thread, other threads:[~2025-09-20 1:37 UTC | newest]
Thread overview: 9+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2025-09-16 22:44 [PATCH] coresight: Fix data argument to coresight_enable_helpers Carl Worth
2025-09-17 1:35 ` Jie Gan
2025-09-17 9:37 ` Leo Yan
2025-09-18 22:18 ` Carl Worth
2025-09-19 1:20 ` Jie Gan
2025-09-19 7:43 ` Suzuki K Poulose
2025-09-19 20:12 ` Carl Worth
2025-09-19 17:49 ` [PATCH v2] coresight: Fix data arguments to coresight enable/disable helpers Carl Worth
2025-09-20 1:36 ` Jie Gan
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