* [PATCH v4 0/4] remoteproc: core: Fixes for rproc cdev and add
@ 2021-06-15 19:03 Siddharth Gupta
2021-06-15 19:03 ` [PATCH v4 1/4] remoteproc: core: Move cdev add before device add Siddharth Gupta
` (3 more replies)
0 siblings, 4 replies; 10+ messages in thread
From: Siddharth Gupta @ 2021-06-15 19:03 UTC (permalink / raw)
To: bjorn.andersson, ohad, linux-remoteproc
Cc: Siddharth Gupta, linux-kernel, linux-arm-msm, linux-arm-kernel, psodagud
This patch series contains stability fixes and error handling for remoteproc.
The changes included in this series do the following:
Patch 1: Fixes the creation of the rproc character device.
Patch 2: Validates rproc as the first step of rproc_add().
Patch 3: Fixes rproc cdev remove and the order of dev_del() and cdev_del().
Patch 4: Adds error handling in rproc_add().
v3 -> v4:
- Moved stable from CC to CC in sign-off area.
v2 -> v3:
- Removed extra file that got added by mistake.
v1 -> v2:
- Added extra patch which addresses Bjorn's comments on patch 3
from v1.
- Fixed commit text for patch 2 (s/calling making/making).
Siddharth Gupta (4):
remoteproc: core: Move cdev add before device add
remoteproc: core: Move validate before device add
remoteproc: core: Fix cdev remove and rproc del
remoteproc: core: Cleanup device in case of failure
drivers/remoteproc/remoteproc_cdev.c | 2 +-
drivers/remoteproc/remoteproc_core.c | 27 ++++++++++++++++++---------
2 files changed, 19 insertions(+), 10 deletions(-)
--
Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project
^ permalink raw reply [flat|nested] 10+ messages in thread
* [PATCH v4 1/4] remoteproc: core: Move cdev add before device add
2021-06-15 19:03 [PATCH v4 0/4] remoteproc: core: Fixes for rproc cdev and add Siddharth Gupta
@ 2021-06-15 19:03 ` Siddharth Gupta
2021-06-15 19:03 ` [PATCH v4 2/4] remoteproc: core: Move validate " Siddharth Gupta
` (2 subsequent siblings)
3 siblings, 0 replies; 10+ messages in thread
From: Siddharth Gupta @ 2021-06-15 19:03 UTC (permalink / raw)
To: bjorn.andersson, ohad, linux-remoteproc
Cc: Siddharth Gupta, linux-kernel, linux-arm-msm, linux-arm-kernel,
psodagud, stable
When cdev_add is called after device_add has been called there is no
way for the userspace to know about the addition of a cdev as cdev_add
itself doesn't trigger a uevent notification, or for the kernel to
know about the change to devt. This results in two problems:
- mknod is never called for the cdev and hence no cdev appears on
devtmpfs.
- sysfs links to the new cdev are not established.
The cdev needs to be added and devt assigned before device_add() is
called in order for the relevant sysfs and devtmpfs entries to be
created and the uevent to be properly populated.
Signed-off-by: Siddharth Gupta <sidgup@codeaurora.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Cc: stable@vger.kernel.org
---
drivers/remoteproc/remoteproc_core.c | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)
diff --git a/drivers/remoteproc/remoteproc_core.c b/drivers/remoteproc/remoteproc_core.c
index 6348aaa..9ad8c5f 100644
--- a/drivers/remoteproc/remoteproc_core.c
+++ b/drivers/remoteproc/remoteproc_core.c
@@ -2333,6 +2333,11 @@ int rproc_add(struct rproc *rproc)
struct device *dev = &rproc->dev;
int ret;
+ /* add char device for this remoteproc */
+ ret = rproc_char_device_add(rproc);
+ if (ret < 0)
+ return ret;
+
ret = device_add(dev);
if (ret < 0)
return ret;
@@ -2346,11 +2351,6 @@ int rproc_add(struct rproc *rproc)
/* create debugfs entries */
rproc_create_debug_dir(rproc);
- /* add char device for this remoteproc */
- ret = rproc_char_device_add(rproc);
- if (ret < 0)
- return ret;
-
/* if rproc is marked always-on, request it to boot */
if (rproc->auto_boot) {
ret = rproc_trigger_auto_boot(rproc);
--
Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project
^ permalink raw reply related [flat|nested] 10+ messages in thread
* [PATCH v4 2/4] remoteproc: core: Move validate before device add
2021-06-15 19:03 [PATCH v4 0/4] remoteproc: core: Fixes for rproc cdev and add Siddharth Gupta
2021-06-15 19:03 ` [PATCH v4 1/4] remoteproc: core: Move cdev add before device add Siddharth Gupta
@ 2021-06-15 19:03 ` Siddharth Gupta
2021-06-15 19:06 ` Greg KH
2021-06-15 19:03 ` [PATCH v4 3/4] remoteproc: core: Fix cdev remove and rproc del Siddharth Gupta
2021-06-15 19:03 ` [PATCH v4 4/4] remoteproc: core: Cleanup device in case of failure Siddharth Gupta
3 siblings, 1 reply; 10+ messages in thread
From: Siddharth Gupta @ 2021-06-15 19:03 UTC (permalink / raw)
To: bjorn.andersson, ohad, linux-remoteproc
Cc: Siddharth Gupta, linux-kernel, linux-arm-msm, linux-arm-kernel,
psodagud, stable
We can validate whether the remoteproc is correctly setup before
making the cdev_add and device_add calls. This saves us the
trouble of cleaning up later on.
Signed-off-by: Siddharth Gupta <sidgup@codeaurora.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Cc: stable@vger.kernel.org
---
drivers/remoteproc/remoteproc_core.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/drivers/remoteproc/remoteproc_core.c b/drivers/remoteproc/remoteproc_core.c
index 9ad8c5f..b65fce3 100644
--- a/drivers/remoteproc/remoteproc_core.c
+++ b/drivers/remoteproc/remoteproc_core.c
@@ -2333,16 +2333,16 @@ int rproc_add(struct rproc *rproc)
struct device *dev = &rproc->dev;
int ret;
- /* add char device for this remoteproc */
- ret = rproc_char_device_add(rproc);
+ ret = rproc_validate(rproc);
if (ret < 0)
return ret;
- ret = device_add(dev);
+ /* add char device for this remoteproc */
+ ret = rproc_char_device_add(rproc);
if (ret < 0)
return ret;
- ret = rproc_validate(rproc);
+ ret = device_add(dev);
if (ret < 0)
return ret;
--
Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project
^ permalink raw reply related [flat|nested] 10+ messages in thread
* [PATCH v4 3/4] remoteproc: core: Fix cdev remove and rproc del
2021-06-15 19:03 [PATCH v4 0/4] remoteproc: core: Fixes for rproc cdev and add Siddharth Gupta
2021-06-15 19:03 ` [PATCH v4 1/4] remoteproc: core: Move cdev add before device add Siddharth Gupta
2021-06-15 19:03 ` [PATCH v4 2/4] remoteproc: core: Move validate " Siddharth Gupta
@ 2021-06-15 19:03 ` Siddharth Gupta
2021-06-15 19:06 ` Greg KH
2021-06-15 19:03 ` [PATCH v4 4/4] remoteproc: core: Cleanup device in case of failure Siddharth Gupta
3 siblings, 1 reply; 10+ messages in thread
From: Siddharth Gupta @ 2021-06-15 19:03 UTC (permalink / raw)
To: bjorn.andersson, ohad, linux-remoteproc
Cc: Siddharth Gupta, linux-kernel, linux-arm-msm, linux-arm-kernel,
psodagud, stable
The rproc_char_device_remove() call currently unmaps the cdev
region instead of simply deleting the cdev that was added as a
part of the rproc_char_device_add() call. This change fixes that
behaviour, and also fixes the order in which device_del() and
cdev_del() need to be called.
Signed-off-by: Siddharth Gupta <sidgup@codeaurora.org>
Cc: stable@vger.kernel.org
---
drivers/remoteproc/remoteproc_cdev.c | 2 +-
drivers/remoteproc/remoteproc_core.c | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/remoteproc/remoteproc_cdev.c b/drivers/remoteproc/remoteproc_cdev.c
index 0b8a84c..4ad98b0 100644
--- a/drivers/remoteproc/remoteproc_cdev.c
+++ b/drivers/remoteproc/remoteproc_cdev.c
@@ -124,7 +124,7 @@ int rproc_char_device_add(struct rproc *rproc)
void rproc_char_device_remove(struct rproc *rproc)
{
- __unregister_chrdev(MAJOR(rproc->dev.devt), rproc->index, 1, "remoteproc");
+ cdev_del(&rproc->cdev);
}
void __init rproc_init_cdev(void)
diff --git a/drivers/remoteproc/remoteproc_core.c b/drivers/remoteproc/remoteproc_core.c
index b65fce3..b874280 100644
--- a/drivers/remoteproc/remoteproc_core.c
+++ b/drivers/remoteproc/remoteproc_core.c
@@ -2619,7 +2619,6 @@ int rproc_del(struct rproc *rproc)
mutex_unlock(&rproc->lock);
rproc_delete_debug_dir(rproc);
- rproc_char_device_remove(rproc);
/* the rproc is downref'ed as soon as it's removed from the klist */
mutex_lock(&rproc_list_mutex);
@@ -2630,6 +2629,7 @@ int rproc_del(struct rproc *rproc)
synchronize_rcu();
device_del(&rproc->dev);
+ rproc_char_device_remove(rproc);
return 0;
}
--
Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project
^ permalink raw reply related [flat|nested] 10+ messages in thread
* [PATCH v4 4/4] remoteproc: core: Cleanup device in case of failure
2021-06-15 19:03 [PATCH v4 0/4] remoteproc: core: Fixes for rproc cdev and add Siddharth Gupta
` (2 preceding siblings ...)
2021-06-15 19:03 ` [PATCH v4 3/4] remoteproc: core: Fix cdev remove and rproc del Siddharth Gupta
@ 2021-06-15 19:03 ` Siddharth Gupta
2021-06-15 19:06 ` Greg KH
3 siblings, 1 reply; 10+ messages in thread
From: Siddharth Gupta @ 2021-06-15 19:03 UTC (permalink / raw)
To: bjorn.andersson, ohad, linux-remoteproc
Cc: Siddharth Gupta, linux-kernel, linux-arm-msm, linux-arm-kernel,
psodagud, stable
When a failure occurs in rproc_add() it returns an error, but does
not cleanup after itself. This change adds the failure path in such
cases.
Signed-off-by: Siddharth Gupta <sidgup@codeaurora.org>
Cc: stable@vger.kernel.org
---
drivers/remoteproc/remoteproc_core.c | 15 ++++++++++++---
1 file changed, 12 insertions(+), 3 deletions(-)
diff --git a/drivers/remoteproc/remoteproc_core.c b/drivers/remoteproc/remoteproc_core.c
index b874280..d823f70 100644
--- a/drivers/remoteproc/remoteproc_core.c
+++ b/drivers/remoteproc/remoteproc_core.c
@@ -2343,8 +2343,10 @@ int rproc_add(struct rproc *rproc)
return ret;
ret = device_add(dev);
- if (ret < 0)
- return ret;
+ if (ret < 0) {
+ put_device(dev);
+ goto rproc_remove_cdev;
+ }
dev_info(dev, "%s is available\n", rproc->name);
@@ -2355,7 +2357,7 @@ int rproc_add(struct rproc *rproc)
if (rproc->auto_boot) {
ret = rproc_trigger_auto_boot(rproc);
if (ret < 0)
- return ret;
+ goto rproc_remove_dev;
}
/* expose to rproc_get_by_phandle users */
@@ -2364,6 +2366,13 @@ int rproc_add(struct rproc *rproc)
mutex_unlock(&rproc_list_mutex);
return 0;
+
+rproc_remove_dev:
+ rproc_delete_debug_dir(rproc);
+ device_del(dev);
+rproc_remove_cdev:
+ rproc_char_device_remove(rproc);
+ return ret;
}
EXPORT_SYMBOL(rproc_add);
--
Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project
^ permalink raw reply related [flat|nested] 10+ messages in thread
* Re: [PATCH v4 2/4] remoteproc: core: Move validate before device add
2021-06-15 19:03 ` [PATCH v4 2/4] remoteproc: core: Move validate " Siddharth Gupta
@ 2021-06-15 19:06 ` Greg KH
0 siblings, 0 replies; 10+ messages in thread
From: Greg KH @ 2021-06-15 19:06 UTC (permalink / raw)
To: Siddharth Gupta
Cc: bjorn.andersson, ohad, linux-remoteproc, linux-kernel,
linux-arm-msm, linux-arm-kernel, psodagud, stable
On Tue, Jun 15, 2021 at 12:03:42PM -0700, Siddharth Gupta wrote:
> We can validate whether the remoteproc is correctly setup before
> making the cdev_add and device_add calls. This saves us the
> trouble of cleaning up later on.
>
> Signed-off-by: Siddharth Gupta <sidgup@codeaurora.org>
> Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
> Cc: stable@vger.kernel.org
> ---
> drivers/remoteproc/remoteproc_core.c | 8 ++++----
> 1 file changed, 4 insertions(+), 4 deletions(-)
>
Why is this relevant for stable? What commit does this fix? Please put
a Fixes: tag for that.
thanks,
greg k-h
^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH v4 4/4] remoteproc: core: Cleanup device in case of failure
2021-06-15 19:03 ` [PATCH v4 4/4] remoteproc: core: Cleanup device in case of failure Siddharth Gupta
@ 2021-06-15 19:06 ` Greg KH
2021-06-15 20:21 ` Siddharth Gupta
0 siblings, 1 reply; 10+ messages in thread
From: Greg KH @ 2021-06-15 19:06 UTC (permalink / raw)
To: Siddharth Gupta
Cc: bjorn.andersson, ohad, linux-remoteproc, linux-kernel,
linux-arm-msm, linux-arm-kernel, psodagud, stable
On Tue, Jun 15, 2021 at 12:03:44PM -0700, Siddharth Gupta wrote:
> When a failure occurs in rproc_add() it returns an error, but does
> not cleanup after itself. This change adds the failure path in such
> cases.
>
> Signed-off-by: Siddharth Gupta <sidgup@codeaurora.org>
> Cc: stable@vger.kernel.org
> ---
> drivers/remoteproc/remoteproc_core.c | 15 ++++++++++++---
> 1 file changed, 12 insertions(+), 3 deletions(-)
Why is this needed for stable kernels? And again, a Fixes: tag?
^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH v4 3/4] remoteproc: core: Fix cdev remove and rproc del
2021-06-15 19:03 ` [PATCH v4 3/4] remoteproc: core: Fix cdev remove and rproc del Siddharth Gupta
@ 2021-06-15 19:06 ` Greg KH
0 siblings, 0 replies; 10+ messages in thread
From: Greg KH @ 2021-06-15 19:06 UTC (permalink / raw)
To: Siddharth Gupta
Cc: bjorn.andersson, ohad, linux-remoteproc, linux-kernel,
linux-arm-msm, linux-arm-kernel, psodagud, stable
On Tue, Jun 15, 2021 at 12:03:43PM -0700, Siddharth Gupta wrote:
> The rproc_char_device_remove() call currently unmaps the cdev
> region instead of simply deleting the cdev that was added as a
> part of the rproc_char_device_add() call. This change fixes that
> behaviour, and also fixes the order in which device_del() and
> cdev_del() need to be called.
>
> Signed-off-by: Siddharth Gupta <sidgup@codeaurora.org>
> Cc: stable@vger.kernel.org
Is this really needed for stable? What bug does this solve? ANd again,
fixes: ?
^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH v4 4/4] remoteproc: core: Cleanup device in case of failure
2021-06-15 19:06 ` Greg KH
@ 2021-06-15 20:21 ` Siddharth Gupta
2021-06-16 5:56 ` Greg KH
0 siblings, 1 reply; 10+ messages in thread
From: Siddharth Gupta @ 2021-06-15 20:21 UTC (permalink / raw)
To: Greg KH
Cc: bjorn.andersson, ohad, linux-remoteproc, linux-kernel,
linux-arm-msm, linux-arm-kernel, psodagud, stable
On 6/15/2021 12:06 PM, Greg KH wrote:
> On Tue, Jun 15, 2021 at 12:03:44PM -0700, Siddharth Gupta wrote:
>> When a failure occurs in rproc_add() it returns an error, but does
>> not cleanup after itself. This change adds the failure path in such
>> cases.
>>
>> Signed-off-by: Siddharth Gupta <sidgup@codeaurora.org>
>> Cc: stable@vger.kernel.org
>> ---
>> drivers/remoteproc/remoteproc_core.c | 15 ++++++++++++---
>> 1 file changed, 12 insertions(+), 3 deletions(-)
> Why is this needed for stable kernels? And again, a Fixes: tag?
Patch 2 and patch 3 are leading up to fix rproc_add()
in case of a failure. This means we'll have errors with
use after free unless we call device_del() or cdev_del(),
also the sysfs and devtempfs nodes will also not be
removed.
Thanks,
Sid
^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH v4 4/4] remoteproc: core: Cleanup device in case of failure
2021-06-15 20:21 ` Siddharth Gupta
@ 2021-06-16 5:56 ` Greg KH
0 siblings, 0 replies; 10+ messages in thread
From: Greg KH @ 2021-06-16 5:56 UTC (permalink / raw)
To: Siddharth Gupta
Cc: bjorn.andersson, ohad, linux-remoteproc, linux-kernel,
linux-arm-msm, linux-arm-kernel, psodagud, stable
On Tue, Jun 15, 2021 at 01:21:11PM -0700, Siddharth Gupta wrote:
>
> On 6/15/2021 12:06 PM, Greg KH wrote:
> > On Tue, Jun 15, 2021 at 12:03:44PM -0700, Siddharth Gupta wrote:
> > > When a failure occurs in rproc_add() it returns an error, but does
> > > not cleanup after itself. This change adds the failure path in such
> > > cases.
> > >
> > > Signed-off-by: Siddharth Gupta <sidgup@codeaurora.org>
> > > Cc: stable@vger.kernel.org
> > > ---
> > > drivers/remoteproc/remoteproc_core.c | 15 ++++++++++++---
> > > 1 file changed, 12 insertions(+), 3 deletions(-)
> > Why is this needed for stable kernels? And again, a Fixes: tag?
> Patch 2 and patch 3 are leading up to fix rproc_add()
> in case of a failure. This means we'll have errors with
> use after free unless we call device_del() or cdev_del(),
> also the sysfs and devtempfs nodes will also not be
> removed.
Then please explain that better in the changelogs. At it is, no one
knows this.
greg k-h
^ permalink raw reply [flat|nested] 10+ messages in thread
end of thread, other threads:[~2021-06-16 5:57 UTC | newest]
Thread overview: 10+ messages (download: mbox.gz / follow: Atom feed)
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2021-06-15 19:03 [PATCH v4 0/4] remoteproc: core: Fixes for rproc cdev and add Siddharth Gupta
2021-06-15 19:03 ` [PATCH v4 1/4] remoteproc: core: Move cdev add before device add Siddharth Gupta
2021-06-15 19:03 ` [PATCH v4 2/4] remoteproc: core: Move validate " Siddharth Gupta
2021-06-15 19:06 ` Greg KH
2021-06-15 19:03 ` [PATCH v4 3/4] remoteproc: core: Fix cdev remove and rproc del Siddharth Gupta
2021-06-15 19:06 ` Greg KH
2021-06-15 19:03 ` [PATCH v4 4/4] remoteproc: core: Cleanup device in case of failure Siddharth Gupta
2021-06-15 19:06 ` Greg KH
2021-06-15 20:21 ` Siddharth Gupta
2021-06-16 5:56 ` Greg KH
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