FAILED: patch "[PATCH] mm, slab: clean up slab->obj_exts always" failed to apply to 6.14-stable tree

FAILED: patch "[PATCH] mm, slab: clean up slab->obj_exts always" failed to apply to 6.14-stable tree

[gregkh]

The patch below does not apply to the 6.14-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-6.14.y
git checkout FETCH_HEAD
git cherry-pick -x be8250786ca94952a19ce87f98ad9906448bc9ef
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2025050521-provable-extent-4108@gregkh' --subject-prefix 'PATCH 6.14.y' HEAD^..

Possible dependencies:



thanks,

greg k-h

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

From be8250786ca94952a19ce87f98ad9906448bc9ef Mon Sep 17 00:00:00 2001
From: Zhenhua Huang <quic_zhenhuah@quicinc.com>
Date: Mon, 21 Apr 2025 15:52:32 +0800
Subject: [PATCH] mm, slab: clean up slab->obj_exts always

When memory allocation profiling is disabled at runtime or due to an
error, shutdown_mem_profiling() is called: slab->obj_exts which
previously allocated remains.
It won't be cleared by unaccount_slab() because of
mem_alloc_profiling_enabled() not true. It's incorrect, slab->obj_exts
should always be cleaned up in unaccount_slab() to avoid following error:

[...]BUG: Bad page state in process...
..
[...]page dumped because: page still charged to cgroup

[andriy.shevchenko@linux.intel.com: fold need_slab_obj_ext() into its only user]
Fixes: 21c690a349ba ("mm: introduce slabobj_ext to support slab object extensions")
Cc: stable@vger.kernel.org
Signed-off-by: Zhenhua Huang <quic_zhenhuah@quicinc.com>
Acked-by: David Rientjes <rientjes@google.com>
Acked-by: Harry Yoo <harry.yoo@oracle.com>
Tested-by: Harry Yoo <harry.yoo@oracle.com>
Acked-by: Suren Baghdasaryan <surenb@google.com>
Link: https://patch.msgid.link/20250421075232.2165527-1-quic_zhenhuah@quicinc.com
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>

diff --git a/mm/slub.c b/mm/slub.c
index dc9e729e1d26..be8b09e09d30 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -2028,8 +2028,7 @@ int alloc_slab_obj_exts(struct slab *slab, struct kmem_cache *s,
 	return 0;
 }
 
-/* Should be called only if mem_alloc_profiling_enabled() */
-static noinline void free_slab_obj_exts(struct slab *slab)
+static inline void free_slab_obj_exts(struct slab *slab)
 {
 	struct slabobj_ext *obj_exts;
 
@@ -2049,18 +2048,6 @@ static noinline void free_slab_obj_exts(struct slab *slab)
 	slab->obj_exts = 0;
 }
 
-static inline bool need_slab_obj_ext(void)
-{
-	if (mem_alloc_profiling_enabled())
-		return true;
-
-	/*
-	 * CONFIG_MEMCG creates vector of obj_cgroup objects conditionally
-	 * inside memcg_slab_post_alloc_hook. No other users for now.
-	 */
-	return false;
-}
-
 #else /* CONFIG_SLAB_OBJ_EXT */
 
 static inline void init_slab_obj_exts(struct slab *slab)
@@ -2077,11 +2064,6 @@ static inline void free_slab_obj_exts(struct slab *slab)
 {
 }
 
-static inline bool need_slab_obj_ext(void)
-{
-	return false;
-}
-
 #endif /* CONFIG_SLAB_OBJ_EXT */
 
 #ifdef CONFIG_MEM_ALLOC_PROFILING
@@ -2129,7 +2111,7 @@ __alloc_tagging_slab_alloc_hook(struct kmem_cache *s, void *object, gfp_t flags)
 static inline void
 alloc_tagging_slab_alloc_hook(struct kmem_cache *s, void *object, gfp_t flags)
 {
-	if (need_slab_obj_ext())
+	if (mem_alloc_profiling_enabled())
 		__alloc_tagging_slab_alloc_hook(s, object, flags);
 }
 
@@ -2601,8 +2583,12 @@ static __always_inline void account_slab(struct slab *slab, int order,
 static __always_inline void unaccount_slab(struct slab *slab, int order,
 					   struct kmem_cache *s)
 {
-	if (memcg_kmem_online() || need_slab_obj_ext())
-		free_slab_obj_exts(slab);
+	/*
+	 * The slab object extensions should now be freed regardless of
+	 * whether mem_alloc_profiling_enabled() or not because profiling
+	 * might have been disabled after slab->obj_exts got allocated.
+	 */
+	free_slab_obj_exts(slab);
 
 	mod_node_page_state(slab_pgdat(slab), cache_vmstat_idx(s),
 			    -(PAGE_SIZE << order));

Re: FAILED: patch "[PATCH] mm, slab: clean up slab->obj_exts always" failed to apply to 6.14-stable tree

[Suren Baghdasaryan]

On Mon, May 5, 2025 at 12:55 AM <gregkh@linuxfoundation.org> wrote:
>
>
> The patch below does not apply to the 6.14-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>.

I'll work on the backport. Thanks!

>
> 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-6.14.y
> git checkout FETCH_HEAD
> git cherry-pick -x be8250786ca94952a19ce87f98ad9906448bc9ef
> # <resolve conflicts, build, test, etc.>
> git commit -s
> git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2025050521-provable-extent-4108@gregkh' --subject-prefix 'PATCH 6.14.y' HEAD^..
>
> Possible dependencies:
>
>
>
> thanks,
>
> greg k-h
>
> ------------------ original commit in Linus's tree ------------------
>
> From be8250786ca94952a19ce87f98ad9906448bc9ef Mon Sep 17 00:00:00 2001
> From: Zhenhua Huang <quic_zhenhuah@quicinc.com>
> Date: Mon, 21 Apr 2025 15:52:32 +0800
> Subject: [PATCH] mm, slab: clean up slab->obj_exts always
>
> When memory allocation profiling is disabled at runtime or due to an
> error, shutdown_mem_profiling() is called: slab->obj_exts which
> previously allocated remains.
> It won't be cleared by unaccount_slab() because of
> mem_alloc_profiling_enabled() not true. It's incorrect, slab->obj_exts
> should always be cleaned up in unaccount_slab() to avoid following error:
>
> [...]BUG: Bad page state in process...
> ..
> [...]page dumped because: page still charged to cgroup
>
> [andriy.shevchenko@linux.intel.com: fold need_slab_obj_ext() into its only user]
> Fixes: 21c690a349ba ("mm: introduce slabobj_ext to support slab object extensions")
> Cc: stable@vger.kernel.org
> Signed-off-by: Zhenhua Huang <quic_zhenhuah@quicinc.com>
> Acked-by: David Rientjes <rientjes@google.com>
> Acked-by: Harry Yoo <harry.yoo@oracle.com>
> Tested-by: Harry Yoo <harry.yoo@oracle.com>
> Acked-by: Suren Baghdasaryan <surenb@google.com>
> Link: https://patch.msgid.link/20250421075232.2165527-1-quic_zhenhuah@quicinc.com
> Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
>
> diff --git a/mm/slub.c b/mm/slub.c
> index dc9e729e1d26..be8b09e09d30 100644
> --- a/mm/slub.c
> +++ b/mm/slub.c
> @@ -2028,8 +2028,7 @@ int alloc_slab_obj_exts(struct slab *slab, struct kmem_cache *s,
>         return 0;
>  }
>
> -/* Should be called only if mem_alloc_profiling_enabled() */
> -static noinline void free_slab_obj_exts(struct slab *slab)
> +static inline void free_slab_obj_exts(struct slab *slab)
>  {
>         struct slabobj_ext *obj_exts;
>
> @@ -2049,18 +2048,6 @@ static noinline void free_slab_obj_exts(struct slab *slab)
>         slab->obj_exts = 0;
>  }
>
> -static inline bool need_slab_obj_ext(void)
> -{
> -       if (mem_alloc_profiling_enabled())
> -               return true;
> -
> -       /*
> -        * CONFIG_MEMCG creates vector of obj_cgroup objects conditionally
> -        * inside memcg_slab_post_alloc_hook. No other users for now.
> -        */
> -       return false;
> -}
> -
>  #else /* CONFIG_SLAB_OBJ_EXT */
>
>  static inline void init_slab_obj_exts(struct slab *slab)
> @@ -2077,11 +2064,6 @@ static inline void free_slab_obj_exts(struct slab *slab)
>  {
>  }
>
> -static inline bool need_slab_obj_ext(void)
> -{
> -       return false;
> -}
> -
>  #endif /* CONFIG_SLAB_OBJ_EXT */
>
>  #ifdef CONFIG_MEM_ALLOC_PROFILING
> @@ -2129,7 +2111,7 @@ __alloc_tagging_slab_alloc_hook(struct kmem_cache *s, void *object, gfp_t flags)
>  static inline void
>  alloc_tagging_slab_alloc_hook(struct kmem_cache *s, void *object, gfp_t flags)
>  {
> -       if (need_slab_obj_ext())
> +       if (mem_alloc_profiling_enabled())
>                 __alloc_tagging_slab_alloc_hook(s, object, flags);
>  }
>
> @@ -2601,8 +2583,12 @@ static __always_inline void account_slab(struct slab *slab, int order,
>  static __always_inline void unaccount_slab(struct slab *slab, int order,
>                                            struct kmem_cache *s)
>  {
> -       if (memcg_kmem_online() || need_slab_obj_ext())
> -               free_slab_obj_exts(slab);
> +       /*
> +        * The slab object extensions should now be freed regardless of
> +        * whether mem_alloc_profiling_enabled() or not because profiling
> +        * might have been disabled after slab->obj_exts got allocated.
> +        */
> +       free_slab_obj_exts(slab);
>
>         mod_node_page_state(slab_pgdat(slab), cache_vmstat_idx(s),
>                             -(PAGE_SIZE << order));
>

[PATCH 6.14.y] mm, slab: clean up slab->obj_exts always

[Suren Baghdasaryan]

From: Zhenhua Huang <quic_zhenhuah@quicinc.com>

When memory allocation profiling is disabled at runtime or due to an
error, shutdown_mem_profiling() is called: slab->obj_exts which
previously allocated remains.
It won't be cleared by unaccount_slab() because of
mem_alloc_profiling_enabled() not true. It's incorrect, slab->obj_exts
should always be cleaned up in unaccount_slab() to avoid following error:

[...]BUG: Bad page state in process...
..
[...]page dumped because: page still charged to cgroup

[andriy.shevchenko@linux.intel.com: fold need_slab_obj_ext() into its only user]
Fixes: 21c690a349ba ("mm: introduce slabobj_ext to support slab object extensions")
Cc: stable@vger.kernel.org
Signed-off-by: Zhenhua Huang <quic_zhenhuah@quicinc.com>
Acked-by: David Rientjes <rientjes@google.com>
Acked-by: Harry Yoo <harry.yoo@oracle.com>
Tested-by: Harry Yoo <harry.yoo@oracle.com>
Acked-by: Suren Baghdasaryan <surenb@google.com>
Link: https://patch.msgid.link/20250421075232.2165527-1-quic_zhenhuah@quicinc.com
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
(cherry picked from commit be8250786ca94952a19ce87f98ad9906448bc9ef)
[surenb: fixed trivial merge conflict in alloc_tagging_slab_alloc_hook(),
skipped inlining free_slab_obj_exts() as it's already inline in 6.14]
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
---
 mm/slub.c | 27 +++++++--------------------
 1 file changed, 7 insertions(+), 20 deletions(-)

diff --git a/mm/slub.c b/mm/slub.c
index 96babca6b330..87f3edf9acb8 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -2025,18 +2025,6 @@ static inline void free_slab_obj_exts(struct slab *slab)
 	slab->obj_exts = 0;
 }
 
-static inline bool need_slab_obj_ext(void)
-{
-	if (mem_alloc_profiling_enabled())
-		return true;
-
-	/*
-	 * CONFIG_MEMCG creates vector of obj_cgroup objects conditionally
-	 * inside memcg_slab_post_alloc_hook. No other users for now.
-	 */
-	return false;
-}
-
 #else /* CONFIG_SLAB_OBJ_EXT */
 
 static inline void init_slab_obj_exts(struct slab *slab)
@@ -2053,11 +2041,6 @@ static inline void free_slab_obj_exts(struct slab *slab)
 {
 }
 
-static inline bool need_slab_obj_ext(void)
-{
-	return false;
-}
-
 #endif /* CONFIG_SLAB_OBJ_EXT */
 
 #ifdef CONFIG_MEM_ALLOC_PROFILING
@@ -2089,7 +2072,7 @@ prepare_slab_obj_exts_hook(struct kmem_cache *s, gfp_t flags, void *p)
 static inline void
 alloc_tagging_slab_alloc_hook(struct kmem_cache *s, void *object, gfp_t flags)
 {
-	if (need_slab_obj_ext()) {
+	if (mem_alloc_profiling_enabled()) {
 		struct slabobj_ext *obj_exts;
 
 		obj_exts = prepare_slab_obj_exts_hook(s, flags, object);
@@ -2565,8 +2548,12 @@ static __always_inline void account_slab(struct slab *slab, int order,
 static __always_inline void unaccount_slab(struct slab *slab, int order,
 					   struct kmem_cache *s)
 {
-	if (memcg_kmem_online() || need_slab_obj_ext())
-		free_slab_obj_exts(slab);
+	/*
+	 * The slab object extensions should now be freed regardless of
+	 * whether mem_alloc_profiling_enabled() or not because profiling
+	 * might have been disabled after slab->obj_exts got allocated.
+	 */
+	free_slab_obj_exts(slab);
 
 	mod_node_page_state(slab_pgdat(slab), cache_vmstat_idx(s),
 			    -(PAGE_SIZE << order));
-- 
2.49.0.967.g6a0df3ecc3-goog

Re: FAILED: patch "[PATCH] mm, slab: clean up slab->obj_exts always" failed to apply to 6.14-stable tree

[Suren Baghdasaryan]

On Mon, May 5, 2025 at 10:30 AM Suren Baghdasaryan <surenb@google.com> wrote:
>
> On Mon, May 5, 2025 at 12:55 AM <gregkh@linuxfoundation.org> wrote:
> >
> >
> > The patch below does not apply to the 6.14-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>.
>
> I'll work on the backport. Thanks!

Posted both 6.12 and 6.14 backports.

>
> >
> > 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-6.14.y
> > git checkout FETCH_HEAD
> > git cherry-pick -x be8250786ca94952a19ce87f98ad9906448bc9ef
> > # <resolve conflicts, build, test, etc.>
> > git commit -s
> > git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2025050521-provable-extent-4108@gregkh' --subject-prefix 'PATCH 6.14.y' HEAD^..
> >
> > Possible dependencies:
> >
> >
> >
> > thanks,
> >
> > greg k-h
> >
> > ------------------ original commit in Linus's tree ------------------
> >
> > From be8250786ca94952a19ce87f98ad9906448bc9ef Mon Sep 17 00:00:00 2001
> > From: Zhenhua Huang <quic_zhenhuah@quicinc.com>
> > Date: Mon, 21 Apr 2025 15:52:32 +0800
> > Subject: [PATCH] mm, slab: clean up slab->obj_exts always
> >
> > When memory allocation profiling is disabled at runtime or due to an
> > error, shutdown_mem_profiling() is called: slab->obj_exts which
> > previously allocated remains.
> > It won't be cleared by unaccount_slab() because of
> > mem_alloc_profiling_enabled() not true. It's incorrect, slab->obj_exts
> > should always be cleaned up in unaccount_slab() to avoid following error:
> >
> > [...]BUG: Bad page state in process...
> > ..
> > [...]page dumped because: page still charged to cgroup
> >
> > [andriy.shevchenko@linux.intel.com: fold need_slab_obj_ext() into its only user]
> > Fixes: 21c690a349ba ("mm: introduce slabobj_ext to support slab object extensions")
> > Cc: stable@vger.kernel.org
> > Signed-off-by: Zhenhua Huang <quic_zhenhuah@quicinc.com>
> > Acked-by: David Rientjes <rientjes@google.com>
> > Acked-by: Harry Yoo <harry.yoo@oracle.com>
> > Tested-by: Harry Yoo <harry.yoo@oracle.com>
> > Acked-by: Suren Baghdasaryan <surenb@google.com>
> > Link: https://patch.msgid.link/20250421075232.2165527-1-quic_zhenhuah@quicinc.com
> > Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
> >
> > diff --git a/mm/slub.c b/mm/slub.c
> > index dc9e729e1d26..be8b09e09d30 100644
> > --- a/mm/slub.c
> > +++ b/mm/slub.c
> > @@ -2028,8 +2028,7 @@ int alloc_slab_obj_exts(struct slab *slab, struct kmem_cache *s,
> >         return 0;
> >  }
> >
> > -/* Should be called only if mem_alloc_profiling_enabled() */
> > -static noinline void free_slab_obj_exts(struct slab *slab)
> > +static inline void free_slab_obj_exts(struct slab *slab)
> >  {
> >         struct slabobj_ext *obj_exts;
> >
> > @@ -2049,18 +2048,6 @@ static noinline void free_slab_obj_exts(struct slab *slab)
> >         slab->obj_exts = 0;
> >  }
> >
> > -static inline bool need_slab_obj_ext(void)
> > -{
> > -       if (mem_alloc_profiling_enabled())
> > -               return true;
> > -
> > -       /*
> > -        * CONFIG_MEMCG creates vector of obj_cgroup objects conditionally
> > -        * inside memcg_slab_post_alloc_hook. No other users for now.
> > -        */
> > -       return false;
> > -}
> > -
> >  #else /* CONFIG_SLAB_OBJ_EXT */
> >
> >  static inline void init_slab_obj_exts(struct slab *slab)
> > @@ -2077,11 +2064,6 @@ static inline void free_slab_obj_exts(struct slab *slab)
> >  {
> >  }
> >
> > -static inline bool need_slab_obj_ext(void)
> > -{
> > -       return false;
> > -}
> > -
> >  #endif /* CONFIG_SLAB_OBJ_EXT */
> >
> >  #ifdef CONFIG_MEM_ALLOC_PROFILING
> > @@ -2129,7 +2111,7 @@ __alloc_tagging_slab_alloc_hook(struct kmem_cache *s, void *object, gfp_t flags)
> >  static inline void
> >  alloc_tagging_slab_alloc_hook(struct kmem_cache *s, void *object, gfp_t flags)
> >  {
> > -       if (need_slab_obj_ext())
> > +       if (mem_alloc_profiling_enabled())
> >                 __alloc_tagging_slab_alloc_hook(s, object, flags);
> >  }
> >
> > @@ -2601,8 +2583,12 @@ static __always_inline void account_slab(struct slab *slab, int order,
> >  static __always_inline void unaccount_slab(struct slab *slab, int order,
> >                                            struct kmem_cache *s)
> >  {
> > -       if (memcg_kmem_online() || need_slab_obj_ext())
> > -               free_slab_obj_exts(slab);
> > +       /*
> > +        * The slab object extensions should now be freed regardless of
> > +        * whether mem_alloc_profiling_enabled() or not because profiling
> > +        * might have been disabled after slab->obj_exts got allocated.
> > +        */
> > +       free_slab_obj_exts(slab);
> >
> >         mod_node_page_state(slab_pgdat(slab), cache_vmstat_idx(s),
> >                             -(PAGE_SIZE << order));
> >