FAILED: patch "[PATCH] drm: Select DRM_KMS_HELPER from" failed to apply to 6.6-stable tree

FAILED: patch "[PATCH] drm: Select DRM_KMS_HELPER from" failed to apply to 6.6-stable tree

[gregkh]

The patch below does not apply to the 6.6-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y
git checkout FETCH_HEAD
git cherry-pick -x 32dce6b1949a696dc7abddc04de8cbe35c260217
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2025050504-placate-iodize-9693@gregkh' --subject-prefix 'PATCH 6.6.y' HEAD^..

Possible dependencies:



thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 32dce6b1949a696dc7abddc04de8cbe35c260217 Mon Sep 17 00:00:00 2001
From: Janne Grunau <j@jannau.net>
Date: Tue, 4 Mar 2025 20:12:14 +0100
Subject: [PATCH] drm: Select DRM_KMS_HELPER from
 DRM_DEBUG_DP_MST_TOPOLOGY_REFS

Using "depends on" and "select" for the same Kconfig symbol is known to
cause circular dependencies (cmp. "Kconfig recursive dependency
limitations" in Documentation/kbuild/kconfig-language.rst.
DRM drivers are selecting drm helpers so do the same for
DRM_DEBUG_DP_MST_TOPOLOGY_REFS.
Fixes following circular dependency reported on x86 for the downstream
Asahi Linux tree:

error: recursive dependency detected!
  symbol DRM_KMS_HELPER is selected by DRM_GEM_SHMEM_HELPER
  symbol DRM_GEM_SHMEM_HELPER is selected by RUST_DRM_GEM_SHMEM_HELPER
  symbol RUST_DRM_GEM_SHMEM_HELPER is selected by DRM_ASAHI
  symbol DRM_ASAHI depends on RUST
  symbol RUST depends on CALL_PADDING
  symbol CALL_PADDING depends on OBJTOOL
  symbol OBJTOOL is selected by STACK_VALIDATION
  symbol STACK_VALIDATION depends on UNWINDER_FRAME_POINTER
  symbol UNWINDER_FRAME_POINTER is part of choice block at arch/x86/Kconfig.debug:224
  symbol <choice> unknown is visible depending on UNWINDER_GUESS
  symbol UNWINDER_GUESS prompt is visible depending on STACKDEPOT
  symbol STACKDEPOT is selected by DRM_DEBUG_DP_MST_TOPOLOGY_REFS
  symbol DRM_DEBUG_DP_MST_TOPOLOGY_REFS depends on DRM_KMS_HELPER

Fixes: 12a280c72868 ("drm/dp_mst: Add topology ref history tracking for debugging")
Cc: stable@vger.kernel.org
Signed-off-by: Janne Grunau <j@jannau.net>
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://lore.kernel.org/r/20250304-drm_debug_dp_mst_topo_kconfig-v1-1-e16fd152f258@jannau.net
Signed-off-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>

diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig
index 2cba2b6ebe1c..f01925ed8176 100644
--- a/drivers/gpu/drm/Kconfig
+++ b/drivers/gpu/drm/Kconfig
@@ -188,7 +188,7 @@ config DRM_DEBUG_DP_MST_TOPOLOGY_REFS
         bool "Enable refcount backtrace history in the DP MST helpers"
 	depends on STACKTRACE_SUPPORT
         select STACKDEPOT
-        depends on DRM_KMS_HELPER
+        select DRM_KMS_HELPER
         depends on DEBUG_KERNEL
         depends on EXPERT
         help

Re: FAILED: patch "[PATCH] drm: Select DRM_KMS_HELPER from" failed to apply to 6.6-stable tree

[Janne Grunau]

Hej,

On Mon, May 5, 2025, at 09:53, gregkh@linuxfoundation.org wrote:
> The patch below does not apply to the 6.6-stable tree. If someone
> wants it applied there, or to any other stable or longterm tree, then
> please email the backport, including the original git commit id to
> <stable@vger.kernel.org>.
>
> To reproduce the conflict and resubmit, you may use the following
> commands:
>
> git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y
> git checkout FETCH_HEAD
> git cherry-pick -x 32dce6b1949a696dc7abddc04de8cbe35c260217

This works for me without conflicts. Are there git configs which might
influence this? The only noticeable thing is that the position of the
DRM_DEBUG_DP_MST_TOPOLOGY_REFS entry shifted 82 lines down. I looked
at the history of drivers/gpu/drm/Kconfig and the config
DRM_DEBUG_DP_MST_TOPOLOGY_REFS block hasn't changed since v5.10. So I
would expect the cherry-pick to work.

Having said all that I don't know how important it is to have this in
older stable releases when nobody noticed it before. The issue presents
itself only with out-of-tree rust DRM drivers. I don't expect that
anyone will try to backport those to old stable releases.

I'm fine with skipping this commit for stable releases for 6.6 and older
and won't post backports.

Janne

Re: FAILED: patch "[PATCH] drm: Select DRM_KMS_HELPER from" failed to apply to 6.6-stable tree

[Greg Kroah-Hartman]

On Mon, May 05, 2025 at 10:33:49AM +0200, Janne Grunau wrote:
> Hej,
> 
> On Mon, May 5, 2025, at 09:53, gregkh@linuxfoundation.org wrote:
> > The patch below does not apply to the 6.6-stable tree. If someone
> > wants it applied there, or to any other stable or longterm tree, then
> > please email the backport, including the original git commit id to
> > <stable@vger.kernel.org>.
> >
> > To reproduce the conflict and resubmit, you may use the following
> > commands:
> >
> > git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y
> > git checkout FETCH_HEAD
> > git cherry-pick -x 32dce6b1949a696dc7abddc04de8cbe35c260217
> 
> This works for me without conflicts. Are there git configs which might
> influence this? The only noticeable thing is that the position of the
> DRM_DEBUG_DP_MST_TOPOLOGY_REFS entry shifted 82 lines down. I looked
> at the history of drivers/gpu/drm/Kconfig and the config
> DRM_DEBUG_DP_MST_TOPOLOGY_REFS block hasn't changed since v5.10. So I
> would expect the cherry-pick to work.

It applies cleanly, but breaks the build badly.  Try it and see :)

> Having said all that I don't know how important it is to have this in
> older stable releases when nobody noticed it before. The issue presents
> itself only with out-of-tree rust DRM drivers. I don't expect that
> anyone will try to backport those to old stable releases.
> 
> I'm fine with skipping this commit for stable releases for 6.6 and older
> and won't post backports.

Ok, thanks!

greg k-h

Re: FAILED: patch "[PATCH] drm: Select DRM_KMS_HELPER from" failed to apply to 6.6-stable tree

[Janne Grunau]

[-- Attachment #1: Type: text/plain, Size: 2011 bytes --]

Hej,

On Mon, May 5, 2025, at 10:49, Greg Kroah-Hartman wrote:
> On Mon, May 05, 2025 at 10:33:49AM +0200, Janne Grunau wrote:
>> Hej,
>> 
>> On Mon, May 5, 2025, at 09:53, gregkh@linuxfoundation.org wrote:
>> > The patch below does not apply to the 6.6-stable tree. If someone
>> > wants it applied there, or to any other stable or longterm tree, then
>> > please email the backport, including the original git commit id to
>> > <stable@vger.kernel.org>.
>> >
>> > To reproduce the conflict and resubmit, you may use the following
>> > commands:
>> >
>> > git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y
>> > git checkout FETCH_HEAD
>> > git cherry-pick -x 32dce6b1949a696dc7abddc04de8cbe35c260217
>> 
>> This works for me without conflicts. Are there git configs which might
>> influence this? The only noticeable thing is that the position of the
>> DRM_DEBUG_DP_MST_TOPOLOGY_REFS entry shifted 82 lines down. I looked
>> at the history of drivers/gpu/drm/Kconfig and the config
>> DRM_DEBUG_DP_MST_TOPOLOGY_REFS block hasn't changed since v5.10. So I
>> would expect the cherry-pick to work.
>
> It applies cleanly, but breaks the build badly.  Try it and see :)

Indeed. The issue is caused by turning CONFIG_DRM_KMS_HELPER from 'm'
to 'y' while leaving CONFIG_DRM as 'm'. This is clearly broken and not intended.
It's exactly what Documentation/kbuild/kconfig-language.rst warns about. OTOH
it also warns about using both 'depends on' and 'select' on the same symbol
which blows up here.
I don't see which change between in v6.6..v6.12 for scripts/kconfig could have
changed this.

Using "select DRM_KMS_HELPER if DRM" fixes the linux-6.6.y build. I only
discovered this as possible solution from the commit message of commit
77a92660d8fe ("kconfig: remove wrong expr_trans_bool()").

CC-ing kconfig maintainer for clarification if "select DRM_KMS_HELPER if
DRM" is a valid solution for this issue. Commit causing issue replicated below
for context.

thanks,
Janne

[-- Attachment #2: 0001-drm-Select-DRM_KMS_HELPER-from-DRM_DEBUG_DP_MST_TOPO.patch --]
[-- Type: text/x-patch, Size: 2407 bytes --]

From 32dce6b1949a696dc7abddc04de8cbe35c260217 Mon Sep 17 00:00:00 2001
From: Janne Grunau <j@jannau.net>
Date: Tue, 4 Mar 2025 20:12:14 +0100
Subject: [PATCH 1/1] drm: Select DRM_KMS_HELPER from
 DRM_DEBUG_DP_MST_TOPOLOGY_REFS

Using "depends on" and "select" for the same Kconfig symbol is known to
cause circular dependencies (cmp. "Kconfig recursive dependency
limitations" in Documentation/kbuild/kconfig-language.rst.
DRM drivers are selecting drm helpers so do the same for
DRM_DEBUG_DP_MST_TOPOLOGY_REFS.
Fixes following circular dependency reported on x86 for the downstream
Asahi Linux tree:

error: recursive dependency detected!
  symbol DRM_KMS_HELPER is selected by DRM_GEM_SHMEM_HELPER
  symbol DRM_GEM_SHMEM_HELPER is selected by RUST_DRM_GEM_SHMEM_HELPER
  symbol RUST_DRM_GEM_SHMEM_HELPER is selected by DRM_ASAHI
  symbol DRM_ASAHI depends on RUST
  symbol RUST depends on CALL_PADDING
  symbol CALL_PADDING depends on OBJTOOL
  symbol OBJTOOL is selected by STACK_VALIDATION
  symbol STACK_VALIDATION depends on UNWINDER_FRAME_POINTER
  symbol UNWINDER_FRAME_POINTER is part of choice block at arch/x86/Kconfig.debug:224
  symbol <choice> unknown is visible depending on UNWINDER_GUESS
  symbol UNWINDER_GUESS prompt is visible depending on STACKDEPOT
  symbol STACKDEPOT is selected by DRM_DEBUG_DP_MST_TOPOLOGY_REFS
  symbol DRM_DEBUG_DP_MST_TOPOLOGY_REFS depends on DRM_KMS_HELPER

Fixes: 12a280c72868 ("drm/dp_mst: Add topology ref history tracking for debugging")
Cc: stable@vger.kernel.org
Signed-off-by: Janne Grunau <j@jannau.net>
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://lore.kernel.org/r/20250304-drm_debug_dp_mst_topo_kconfig-v1-1-e16fd152f258@jannau.net
Signed-off-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>
---
 drivers/gpu/drm/Kconfig | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig
index 2cba2b6ebe1c..f01925ed8176 100644
--- a/drivers/gpu/drm/Kconfig
+++ b/drivers/gpu/drm/Kconfig
@@ -188,7 +188,7 @@ config DRM_DEBUG_DP_MST_TOPOLOGY_REFS
         bool "Enable refcount backtrace history in the DP MST helpers"
 	depends on STACKTRACE_SUPPORT
         select STACKDEPOT
-        depends on DRM_KMS_HELPER
+        select DRM_KMS_HELPER
         depends on DEBUG_KERNEL
         depends on EXPERT
         help
-- 
2.49.0

Re: FAILED: patch "[PATCH] drm: Select DRM_KMS_HELPER from" failed to apply to 6.6-stable tree

[Randy Dunlap]

Hi,

On 5/5/25 3:51 AM, Janne Grunau wrote:
> Hej,
> 
> On Mon, May 5, 2025, at 10:49, Greg Kroah-Hartman wrote:
>> On Mon, May 05, 2025 at 10:33:49AM +0200, Janne Grunau wrote:
>>> Hej,
>>>
>>> On Mon, May 5, 2025, at 09:53, gregkh@linuxfoundation.org wrote:
>>>> The patch below does not apply to the 6.6-stable tree. If someone
>>>> wants it applied there, or to any other stable or longterm tree, then
>>>> please email the backport, including the original git commit id to
>>>> <stable@vger.kernel.org>.
>>>>
>>>> To reproduce the conflict and resubmit, you may use the following
>>>> commands:
>>>>
>>>> git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y
>>>> git checkout FETCH_HEAD
>>>> git cherry-pick -x 32dce6b1949a696dc7abddc04de8cbe35c260217
>>>
>>> This works for me without conflicts. Are there git configs which might
>>> influence this? The only noticeable thing is that the position of the
>>> DRM_DEBUG_DP_MST_TOPOLOGY_REFS entry shifted 82 lines down. I looked
>>> at the history of drivers/gpu/drm/Kconfig and the config
>>> DRM_DEBUG_DP_MST_TOPOLOGY_REFS block hasn't changed since v5.10. So I
>>> would expect the cherry-pick to work.
>>
>> It applies cleanly, but breaks the build badly.  Try it and see :)
> 
> Indeed. The issue is caused by turning CONFIG_DRM_KMS_HELPER from 'm'
> to 'y' while leaving CONFIG_DRM as 'm'. This is clearly broken and not intended.
> It's exactly what Documentation/kbuild/kconfig-language.rst warns about. OTOH
> it also warns about using both 'depends on' and 'select' on the same symbol
> which blows up here.
> I don't see which change between in v6.6..v6.12 for scripts/kconfig could have
> changed this.
> 
> Using "select DRM_KMS_HELPER if DRM" fixes the linux-6.6.y build. I only
> discovered this as possible solution from the commit message of commit
> 77a92660d8fe ("kconfig: remove wrong expr_trans_bool()").
> 
> CC-ing kconfig maintainer for clarification if "select DRM_KMS_HELPER if
> DRM" is a valid solution for this issue. Commit causing issue replicated below
> for context.

I would just add one more line to the Kconfig:

 config DRM_DEBUG_DP_MST_TOPOLOGY_REFS
         bool "Enable refcount backtrace history in the DP MST helpers"
+       depends on DRM
        depends on STACKTRACE_SUPPORT
         select STACKDEPOT
-        depends on DRM_KMS_HELPER
+        select DRM_KMS_HELPER
         depends on DEBUG_KERNEL
         depends on EXPERT
         help

No problems with that in my testing.

-- 
~Randy