When removing the module we will get the following warning:
[ 31.911505] i2c-core: driver [stdp2690-ge-b850v3-fw] unregistered
[ 31.912484] general protection fault, probably for non-canonical address 0xdffffc0000000001: 0000 [#1] PREEMPT SMP KASAN PTI
[ 31.913338] KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f]
[ 31.915280] RIP: 0010:drm_bridge_remove+0x97/0x130
[ 31.921825] Call Trace:
[ 31.922533] stdp4028_ge_b850v3_fw_remove+0x34/0x60 [megachips_stdpxxxx_ge_b850v3_fw]
[ 31.923139] i2c_device_remove+0x181/0x1f0
The two bridges (stdp2690, stdp4028) do not probe at the same time, so
the driver does not call ge_b850v3_resgiter() when probing, causing the
driver to try to remove the object that has not been initialized.
Fix this by checking whether both the bridges are probed.
Signed-off-by: Zheyu Ma <[email protected]>
---
drivers/gpu/drm/bridge/megachips-stdpxxxx-ge-b850v3-fw.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/bridge/megachips-stdpxxxx-ge-b850v3-fw.c b/drivers/gpu/drm/bridge/megachips-stdpxxxx-ge-b850v3-fw.c
index cce98bf2a4e7..c68a4cdf4625 100644
--- a/drivers/gpu/drm/bridge/megachips-stdpxxxx-ge-b850v3-fw.c
+++ b/drivers/gpu/drm/bridge/megachips-stdpxxxx-ge-b850v3-fw.c
@@ -296,7 +296,9 @@ static void ge_b850v3_lvds_remove(void)
* This check is to avoid both the drivers
* removing the bridge in their remove() function
*/
- if (!ge_b850v3_lvds_ptr)
+ if (!ge_b850v3_lvds_ptr ||
+ !ge_b850v3_lvds_ptr->stdp2690_i2c ||
+ !ge_b850v3_lvds_ptr->stdp4028_i2c)
goto out;
drm_bridge_remove(&ge_b850v3_lvds_ptr->bridge);
--
2.25.1
On Sat, 2022-07-16 at 16:13 +0800, Zheyu Ma wrote:
> When removing the module we will get the following warning:
>
> [ 31.911505] i2c-core: driver [stdp2690-ge-b850v3-fw] unregistered
> [ 31.912484] general protection fault, probably for non-canonical
> address 0xdffffc0000000001: 0000 [#1] PREEMPT SMP KASAN PTI
> [ 31.913338] KASAN: null-ptr-deref in range [0x0000000000000008-
> 0x000000000000000f]
> [ 31.915280] RIP: 0010:drm_bridge_remove+0x97/0x130
> [ 31.921825] Call Trace:
> [ 31.922533] stdp4028_ge_b850v3_fw_remove+0x34/0x60
> [megachips_stdpxxxx_ge_b850v3_fw]
> [ 31.923139] i2c_device_remove+0x181/0x1f0
>
> The two bridges (stdp2690, stdp4028) do not probe at the same time,
> so
> the driver does not call ge_b850v3_resgiter() when probing, causing
> the
> driver to try to remove the object that has not been initialized.
>
> Fix this by checking whether both the bridges are probed.
>
> Signed-off-by: Zheyu Ma <[email protected]>
Good catch!
Acked-by: Martyn Welch <[email protected]>
Would be worth adding:
Fixes: 11632d4aa2b3 ("drm/bridge: megachips: Ensure both bridges are
probed before registration")
> ---
> drivers/gpu/drm/bridge/megachips-stdpxxxx-ge-b850v3-fw.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/bridge/megachips-stdpxxxx-ge-b850v3-fw.c
> b/drivers/gpu/drm/bridge/megachips-stdpxxxx-ge-b850v3-fw.c
> index cce98bf2a4e7..c68a4cdf4625 100644
> --- a/drivers/gpu/drm/bridge/megachips-stdpxxxx-ge-b850v3-fw.c
> +++ b/drivers/gpu/drm/bridge/megachips-stdpxxxx-ge-b850v3-fw.c
> @@ -296,7 +296,9 @@ static void ge_b850v3_lvds_remove(void)
> * This check is to avoid both the drivers
> * removing the bridge in their remove() function
> */
> - if (!ge_b850v3_lvds_ptr)
> + if (!ge_b850v3_lvds_ptr ||
> + !ge_b850v3_lvds_ptr->stdp2690_i2c ||
> + !ge_b850v3_lvds_ptr->stdp4028_i2c)
> goto out;
>
> drm_bridge_remove(&ge_b850v3_lvds_ptr->bridge);
On Tue, Jul 19, 2022 at 09:38:16AM +0100, Martyn Welch wrote:
> On Sat, 2022-07-16 at 16:13 +0800, Zheyu Ma wrote:
> > When removing the module we will get the following warning:
> >
> > [?? 31.911505] i2c-core: driver [stdp2690-ge-b850v3-fw] unregistered
> > [?? 31.912484] general protection fault, probably for non-canonical
> > address 0xdffffc0000000001: 0000 [#1] PREEMPT SMP KASAN PTI
> > [?? 31.913338] KASAN: null-ptr-deref in range [0x0000000000000008-
> > 0x000000000000000f]
> > [?? 31.915280] RIP: 0010:drm_bridge_remove+0x97/0x130
> > [?? 31.921825] Call Trace:
> > [?? 31.922533]? stdp4028_ge_b850v3_fw_remove+0x34/0x60
> > [megachips_stdpxxxx_ge_b850v3_fw]
> > [?? 31.923139]? i2c_device_remove+0x181/0x1f0
> >
> > The two bridges (stdp2690, stdp4028) do not probe at the same time,
> > so
> > the driver does not call ge_b850v3_resgiter() when probing, causing
> > the
> > driver to try to remove the object that has not been initialized.
> >
> > Fix this by checking whether both the bridges are probed.
> >
> > Signed-off-by: Zheyu Ma <[email protected]>
>
> Good catch!
>
> Acked-by: Martyn Welch <[email protected]>
Tested-by: Ian Ray <[email protected]>
>
> Would be worth adding:
>
> Fixes: 11632d4aa2b3 ("drm/bridge: megachips: Ensure both bridges are
> probed before registration")
>
> > ---
> > ?drivers/gpu/drm/bridge/megachips-stdpxxxx-ge-b850v3-fw.c | 4 +++-
> > ?1 file changed, 3 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/gpu/drm/bridge/megachips-stdpxxxx-ge-b850v3-fw.c
> > b/drivers/gpu/drm/bridge/megachips-stdpxxxx-ge-b850v3-fw.c
> > index cce98bf2a4e7..c68a4cdf4625 100644
> > --- a/drivers/gpu/drm/bridge/megachips-stdpxxxx-ge-b850v3-fw.c
> > +++ b/drivers/gpu/drm/bridge/megachips-stdpxxxx-ge-b850v3-fw.c
> > @@ -296,7 +296,9 @@ static void ge_b850v3_lvds_remove(void)
> > ???????? * This check is to avoid both the drivers
> > ???????? * removing the bridge in their remove() function
> > ???????? */
> > -???????if (!ge_b850v3_lvds_ptr)
> > +???????if (!ge_b850v3_lvds_ptr ||
> > +???????????????!ge_b850v3_lvds_ptr->stdp2690_i2c ||
> > +???????????????!ge_b850v3_lvds_ptr->stdp4028_i2c)
> > ????????????????goto out;
> > ?
> > ????????drm_bridge_remove(&ge_b850v3_lvds_ptr->bridge);
>
On Sat, 16 Jul 2022 at 10:13, Zheyu Ma <[email protected]> wrote:
>
> When removing the module we will get the following warning:
>
> [ 31.911505] i2c-core: driver [stdp2690-ge-b850v3-fw] unregistered
> [ 31.912484] general protection fault, probably for non-canonical address 0xdffffc0000000001: 0000 [#1] PREEMPT SMP KASAN PTI
> [ 31.913338] KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f]
> [ 31.915280] RIP: 0010:drm_bridge_remove+0x97/0x130
> [ 31.921825] Call Trace:
> [ 31.922533] stdp4028_ge_b850v3_fw_remove+0x34/0x60 [megachips_stdpxxxx_ge_b850v3_fw]
> [ 31.923139] i2c_device_remove+0x181/0x1f0
>
> The two bridges (stdp2690, stdp4028) do not probe at the same time, so
> the driver does not call ge_b850v3_resgiter() when probing, causing the
> driver to try to remove the object that has not been initialized.
>
> Fix this by checking whether both the bridges are probed.
>
> Signed-off-by: Zheyu Ma <[email protected]>
> ---
> drivers/gpu/drm/bridge/megachips-stdpxxxx-ge-b850v3-fw.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/bridge/megachips-stdpxxxx-ge-b850v3-fw.c b/drivers/gpu/drm/bridge/megachips-stdpxxxx-ge-b850v3-fw.c
> index cce98bf2a4e7..c68a4cdf4625 100644
> --- a/drivers/gpu/drm/bridge/megachips-stdpxxxx-ge-b850v3-fw.c
> +++ b/drivers/gpu/drm/bridge/megachips-stdpxxxx-ge-b850v3-fw.c
> @@ -296,7 +296,9 @@ static void ge_b850v3_lvds_remove(void)
> * This check is to avoid both the drivers
> * removing the bridge in their remove() function
> */
> - if (!ge_b850v3_lvds_ptr)
> + if (!ge_b850v3_lvds_ptr ||
> + !ge_b850v3_lvds_ptr->stdp2690_i2c ||
> + !ge_b850v3_lvds_ptr->stdp4028_i2c)
This chunk fails checkpatch --strict.
Alignment should match open parenthesis
#39: FILE: drivers/gpu/drm/bridge/megachips-stdpxxxx-ge-b850v3-fw.c:300:
> goto out;
>
> drm_bridge_remove(&ge_b850v3_lvds_ptr->bridge);
> --
> 2.25.1
>
Hi Robert,
On Mon, Aug 29, 2022 at 11:03 PM Robert Foss <[email protected]> wrote:
>
> On Sat, 16 Jul 2022 at 10:13, Zheyu Ma <[email protected]> wrote:
> >
> > When removing the module we will get the following warning:
> >
> > [ 31.911505] i2c-core: driver [stdp2690-ge-b850v3-fw] unregistered
> > [ 31.912484] general protection fault, probably for non-canonical address 0xdffffc0000000001: 0000 [#1] PREEMPT SMP KASAN PTI
> > [ 31.913338] KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f]
> > [ 31.915280] RIP: 0010:drm_bridge_remove+0x97/0x130
> > [ 31.921825] Call Trace:
> > [ 31.922533] stdp4028_ge_b850v3_fw_remove+0x34/0x60 [megachips_stdpxxxx_ge_b850v3_fw]
> > [ 31.923139] i2c_device_remove+0x181/0x1f0
> >
> > The two bridges (stdp2690, stdp4028) do not probe at the same time, so
> > the driver does not call ge_b850v3_resgiter() when probing, causing the
> > driver to try to remove the object that has not been initialized.
> >
> > Fix this by checking whether both the bridges are probed.
> >
> > Signed-off-by: Zheyu Ma <[email protected]>
> > ---
> > drivers/gpu/drm/bridge/megachips-stdpxxxx-ge-b850v3-fw.c | 4 +++-
> > 1 file changed, 3 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/gpu/drm/bridge/megachips-stdpxxxx-ge-b850v3-fw.c b/drivers/gpu/drm/bridge/megachips-stdpxxxx-ge-b850v3-fw.c
> > index cce98bf2a4e7..c68a4cdf4625 100644
> > --- a/drivers/gpu/drm/bridge/megachips-stdpxxxx-ge-b850v3-fw.c
> > +++ b/drivers/gpu/drm/bridge/megachips-stdpxxxx-ge-b850v3-fw.c
> > @@ -296,7 +296,9 @@ static void ge_b850v3_lvds_remove(void)
> > * This check is to avoid both the drivers
> > * removing the bridge in their remove() function
> > */
> > - if (!ge_b850v3_lvds_ptr)
> > + if (!ge_b850v3_lvds_ptr ||
> > + !ge_b850v3_lvds_ptr->stdp2690_i2c ||
> > + !ge_b850v3_lvds_ptr->stdp4028_i2c)
>
> This chunk fails checkpatch --strict.
>
> Alignment should match open parenthesis
> #39: FILE: drivers/gpu/drm/bridge/megachips-stdpxxxx-ge-b850v3-fw.c:300:
Thanks for your suggestion, I've sent the version 2 patch.
Regards,
Zheyu Ma