The patch below does not apply to the 5.15-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(a)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-5.15.y
git checkout FETCH_HEAD
git cherry-pick -x 24526268f4e38c9ec0c4a30de4f37ad2a2a84e47
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2023100422-twistable-umbrella-a71d@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 24526268f4e38c9ec0c4a30de4f37ad2a2a84e47 Mon Sep 17 00:00:00 2001
From: Yang Shi <yang(a)os.amperecomputing.com>
Date: Wed, 20 Sep 2023 15:32:42 -0700
Subject: [PATCH] mm: mempolicy: keep VMA walk if both MPOL_MF_STRICT and
MPOL_MF_MOVE are specified
When calling mbind() with MPOL_MF_{MOVE|MOVEALL} | MPOL_MF_STRICT, kernel
should attempt to migrate all existing pages, and return -EIO if there is
misplaced or unmovable page. Then commit 6f4576e3687b ("mempolicy: apply
page table walker on queue_pages_range()") messed up the return value and
didn't break VMA scan early ianymore when MPOL_MF_STRICT alone. The
return value problem was fixed by commit a7f40cfe3b7a ("mm: mempolicy:
make mbind() return -EIO when MPOL_MF_STRICT is specified"), but it broke
the VMA walk early if unmovable page is met, it may cause some pages are
not migrated as expected.
The code should conceptually do:
if (MPOL_MF_MOVE|MOVEALL)
scan all vmas
try to migrate the existing pages
return success
else if (MPOL_MF_MOVE* | MPOL_MF_STRICT)
scan all vmas
try to migrate the existing pages
return -EIO if unmovable or migration failed
else /* MPOL_MF_STRICT alone */
break early if meets unmovable and don't call mbind_range() at all
else /* none of those flags */
check the ranges in test_walk, EFAULT without mbind_range() if discontig.
Fixed the behavior.
Link: https://lkml.kernel.org/r/20230920223242.3425775-1-yang@os.amperecomputing.…
Fixes: a7f40cfe3b7a ("mm: mempolicy: make mbind() return -EIO when MPOL_MF_STRICT is specified")
Signed-off-by: Yang Shi <yang(a)os.amperecomputing.com>
Cc: Hugh Dickins <hughd(a)google.com>
Cc: Suren Baghdasaryan <surenb(a)google.com>
Cc: Matthew Wilcox <willy(a)infradead.org>
Cc: Michal Hocko <mhocko(a)suse.com>
Cc: Vlastimil Babka <vbabka(a)suse.cz>
Cc: Oscar Salvador <osalvador(a)suse.de>
Cc: Rafael Aquini <aquini(a)redhat.com>
Cc: Kirill A. Shutemov <kirill(a)shutemov.name>
Cc: David Rientjes <rientjes(a)google.com>
Cc: <stable(a)vger.kernel.org> [4.9+]
Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org>
diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index 42b5567e3773..f1b00d6ac7ee 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -426,6 +426,7 @@ struct queue_pages {
unsigned long start;
unsigned long end;
struct vm_area_struct *first;
+ bool has_unmovable;
};
/*
@@ -446,9 +447,8 @@ static inline bool queue_folio_required(struct folio *folio,
/*
* queue_folios_pmd() has three possible return values:
* 0 - folios are placed on the right node or queued successfully, or
- * special page is met, i.e. huge zero page.
- * 1 - there is unmovable folio, and MPOL_MF_MOVE* & MPOL_MF_STRICT were
- * specified.
+ * special page is met, i.e. zero page, or unmovable page is found
+ * but continue walking (indicated by queue_pages.has_unmovable).
* -EIO - is migration entry or only MPOL_MF_STRICT was specified and an
* existing folio was already on a node that does not follow the
* policy.
@@ -479,7 +479,7 @@ static int queue_folios_pmd(pmd_t *pmd, spinlock_t *ptl, unsigned long addr,
if (flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL)) {
if (!vma_migratable(walk->vma) ||
migrate_folio_add(folio, qp->pagelist, flags)) {
- ret = 1;
+ qp->has_unmovable = true;
goto unlock;
}
} else
@@ -495,9 +495,8 @@ static int queue_folios_pmd(pmd_t *pmd, spinlock_t *ptl, unsigned long addr,
*
* queue_folios_pte_range() has three possible return values:
* 0 - folios are placed on the right node or queued successfully, or
- * special page is met, i.e. zero page.
- * 1 - there is unmovable folio, and MPOL_MF_MOVE* & MPOL_MF_STRICT were
- * specified.
+ * special page is met, i.e. zero page, or unmovable page is found
+ * but continue walking (indicated by queue_pages.has_unmovable).
* -EIO - only MPOL_MF_STRICT was specified and an existing folio was already
* on a node that does not follow the policy.
*/
@@ -508,7 +507,6 @@ static int queue_folios_pte_range(pmd_t *pmd, unsigned long addr,
struct folio *folio;
struct queue_pages *qp = walk->private;
unsigned long flags = qp->flags;
- bool has_unmovable = false;
pte_t *pte, *mapped_pte;
pte_t ptent;
spinlock_t *ptl;
@@ -538,11 +536,12 @@ static int queue_folios_pte_range(pmd_t *pmd, unsigned long addr,
if (!queue_folio_required(folio, qp))
continue;
if (flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL)) {
- /* MPOL_MF_STRICT must be specified if we get here */
- if (!vma_migratable(vma)) {
- has_unmovable = true;
- break;
- }
+ /*
+ * MPOL_MF_STRICT must be specified if we get here.
+ * Continue walking vmas due to MPOL_MF_MOVE* flags.
+ */
+ if (!vma_migratable(vma))
+ qp->has_unmovable = true;
/*
* Do not abort immediately since there may be
@@ -550,16 +549,13 @@ static int queue_folios_pte_range(pmd_t *pmd, unsigned long addr,
* need migrate other LRU pages.
*/
if (migrate_folio_add(folio, qp->pagelist, flags))
- has_unmovable = true;
+ qp->has_unmovable = true;
} else
break;
}
pte_unmap_unlock(mapped_pte, ptl);
cond_resched();
- if (has_unmovable)
- return 1;
-
return addr != end ? -EIO : 0;
}
@@ -599,7 +595,7 @@ static int queue_folios_hugetlb(pte_t *pte, unsigned long hmask,
* Detecting misplaced folio but allow migrating folios which
* have been queued.
*/
- ret = 1;
+ qp->has_unmovable = true;
goto unlock;
}
@@ -620,7 +616,7 @@ static int queue_folios_hugetlb(pte_t *pte, unsigned long hmask,
* Failed to isolate folio but allow migrating pages
* which have been queued.
*/
- ret = 1;
+ qp->has_unmovable = true;
}
unlock:
spin_unlock(ptl);
@@ -756,12 +752,15 @@ queue_pages_range(struct mm_struct *mm, unsigned long start, unsigned long end,
.start = start,
.end = end,
.first = NULL,
+ .has_unmovable = false,
};
const struct mm_walk_ops *ops = lock_vma ?
&queue_pages_lock_vma_walk_ops : &queue_pages_walk_ops;
err = walk_page_range(mm, start, end, ops, &qp);
+ if (qp.has_unmovable)
+ err = 1;
if (!qp.first)
/* whole range in hole */
err = -EFAULT;
@@ -1358,7 +1357,7 @@ static long do_mbind(unsigned long start, unsigned long len,
putback_movable_pages(&pagelist);
}
- if ((ret > 0) || (nr_failed && (flags & MPOL_MF_STRICT)))
+ if (((ret > 0) || nr_failed) && (flags & MPOL_MF_STRICT))
err = -EIO;
} else {
up_out:
The patch below does not apply to the 6.1-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(a)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-6.1.y
git checkout FETCH_HEAD
git cherry-pick -x 24526268f4e38c9ec0c4a30de4f37ad2a2a84e47
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2023100420-grafting-raft-1e1b@gregkh' --subject-prefix 'PATCH 6.1.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 24526268f4e38c9ec0c4a30de4f37ad2a2a84e47 Mon Sep 17 00:00:00 2001
From: Yang Shi <yang(a)os.amperecomputing.com>
Date: Wed, 20 Sep 2023 15:32:42 -0700
Subject: [PATCH] mm: mempolicy: keep VMA walk if both MPOL_MF_STRICT and
MPOL_MF_MOVE are specified
When calling mbind() with MPOL_MF_{MOVE|MOVEALL} | MPOL_MF_STRICT, kernel
should attempt to migrate all existing pages, and return -EIO if there is
misplaced or unmovable page. Then commit 6f4576e3687b ("mempolicy: apply
page table walker on queue_pages_range()") messed up the return value and
didn't break VMA scan early ianymore when MPOL_MF_STRICT alone. The
return value problem was fixed by commit a7f40cfe3b7a ("mm: mempolicy:
make mbind() return -EIO when MPOL_MF_STRICT is specified"), but it broke
the VMA walk early if unmovable page is met, it may cause some pages are
not migrated as expected.
The code should conceptually do:
if (MPOL_MF_MOVE|MOVEALL)
scan all vmas
try to migrate the existing pages
return success
else if (MPOL_MF_MOVE* | MPOL_MF_STRICT)
scan all vmas
try to migrate the existing pages
return -EIO if unmovable or migration failed
else /* MPOL_MF_STRICT alone */
break early if meets unmovable and don't call mbind_range() at all
else /* none of those flags */
check the ranges in test_walk, EFAULT without mbind_range() if discontig.
Fixed the behavior.
Link: https://lkml.kernel.org/r/20230920223242.3425775-1-yang@os.amperecomputing.…
Fixes: a7f40cfe3b7a ("mm: mempolicy: make mbind() return -EIO when MPOL_MF_STRICT is specified")
Signed-off-by: Yang Shi <yang(a)os.amperecomputing.com>
Cc: Hugh Dickins <hughd(a)google.com>
Cc: Suren Baghdasaryan <surenb(a)google.com>
Cc: Matthew Wilcox <willy(a)infradead.org>
Cc: Michal Hocko <mhocko(a)suse.com>
Cc: Vlastimil Babka <vbabka(a)suse.cz>
Cc: Oscar Salvador <osalvador(a)suse.de>
Cc: Rafael Aquini <aquini(a)redhat.com>
Cc: Kirill A. Shutemov <kirill(a)shutemov.name>
Cc: David Rientjes <rientjes(a)google.com>
Cc: <stable(a)vger.kernel.org> [4.9+]
Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org>
diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index 42b5567e3773..f1b00d6ac7ee 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -426,6 +426,7 @@ struct queue_pages {
unsigned long start;
unsigned long end;
struct vm_area_struct *first;
+ bool has_unmovable;
};
/*
@@ -446,9 +447,8 @@ static inline bool queue_folio_required(struct folio *folio,
/*
* queue_folios_pmd() has three possible return values:
* 0 - folios are placed on the right node or queued successfully, or
- * special page is met, i.e. huge zero page.
- * 1 - there is unmovable folio, and MPOL_MF_MOVE* & MPOL_MF_STRICT were
- * specified.
+ * special page is met, i.e. zero page, or unmovable page is found
+ * but continue walking (indicated by queue_pages.has_unmovable).
* -EIO - is migration entry or only MPOL_MF_STRICT was specified and an
* existing folio was already on a node that does not follow the
* policy.
@@ -479,7 +479,7 @@ static int queue_folios_pmd(pmd_t *pmd, spinlock_t *ptl, unsigned long addr,
if (flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL)) {
if (!vma_migratable(walk->vma) ||
migrate_folio_add(folio, qp->pagelist, flags)) {
- ret = 1;
+ qp->has_unmovable = true;
goto unlock;
}
} else
@@ -495,9 +495,8 @@ static int queue_folios_pmd(pmd_t *pmd, spinlock_t *ptl, unsigned long addr,
*
* queue_folios_pte_range() has three possible return values:
* 0 - folios are placed on the right node or queued successfully, or
- * special page is met, i.e. zero page.
- * 1 - there is unmovable folio, and MPOL_MF_MOVE* & MPOL_MF_STRICT were
- * specified.
+ * special page is met, i.e. zero page, or unmovable page is found
+ * but continue walking (indicated by queue_pages.has_unmovable).
* -EIO - only MPOL_MF_STRICT was specified and an existing folio was already
* on a node that does not follow the policy.
*/
@@ -508,7 +507,6 @@ static int queue_folios_pte_range(pmd_t *pmd, unsigned long addr,
struct folio *folio;
struct queue_pages *qp = walk->private;
unsigned long flags = qp->flags;
- bool has_unmovable = false;
pte_t *pte, *mapped_pte;
pte_t ptent;
spinlock_t *ptl;
@@ -538,11 +536,12 @@ static int queue_folios_pte_range(pmd_t *pmd, unsigned long addr,
if (!queue_folio_required(folio, qp))
continue;
if (flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL)) {
- /* MPOL_MF_STRICT must be specified if we get here */
- if (!vma_migratable(vma)) {
- has_unmovable = true;
- break;
- }
+ /*
+ * MPOL_MF_STRICT must be specified if we get here.
+ * Continue walking vmas due to MPOL_MF_MOVE* flags.
+ */
+ if (!vma_migratable(vma))
+ qp->has_unmovable = true;
/*
* Do not abort immediately since there may be
@@ -550,16 +549,13 @@ static int queue_folios_pte_range(pmd_t *pmd, unsigned long addr,
* need migrate other LRU pages.
*/
if (migrate_folio_add(folio, qp->pagelist, flags))
- has_unmovable = true;
+ qp->has_unmovable = true;
} else
break;
}
pte_unmap_unlock(mapped_pte, ptl);
cond_resched();
- if (has_unmovable)
- return 1;
-
return addr != end ? -EIO : 0;
}
@@ -599,7 +595,7 @@ static int queue_folios_hugetlb(pte_t *pte, unsigned long hmask,
* Detecting misplaced folio but allow migrating folios which
* have been queued.
*/
- ret = 1;
+ qp->has_unmovable = true;
goto unlock;
}
@@ -620,7 +616,7 @@ static int queue_folios_hugetlb(pte_t *pte, unsigned long hmask,
* Failed to isolate folio but allow migrating pages
* which have been queued.
*/
- ret = 1;
+ qp->has_unmovable = true;
}
unlock:
spin_unlock(ptl);
@@ -756,12 +752,15 @@ queue_pages_range(struct mm_struct *mm, unsigned long start, unsigned long end,
.start = start,
.end = end,
.first = NULL,
+ .has_unmovable = false,
};
const struct mm_walk_ops *ops = lock_vma ?
&queue_pages_lock_vma_walk_ops : &queue_pages_walk_ops;
err = walk_page_range(mm, start, end, ops, &qp);
+ if (qp.has_unmovable)
+ err = 1;
if (!qp.first)
/* whole range in hole */
err = -EFAULT;
@@ -1358,7 +1357,7 @@ static long do_mbind(unsigned long start, unsigned long len,
putback_movable_pages(&pagelist);
}
- if ((ret > 0) || (nr_failed && (flags & MPOL_MF_STRICT)))
+ if (((ret > 0) || nr_failed) && (flags & MPOL_MF_STRICT))
err = -EIO;
} else {
up_out:
The patch below does not apply to the 4.14-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(a)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-4.14.y
git checkout FETCH_HEAD
git cherry-pick -x 578d7699e5c2add8c2e9549d9d75dfb56c460cb3
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2023100409-shorten-demanding-15d2@gregkh' --subject-prefix 'PATCH 4.14.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 578d7699e5c2add8c2e9549d9d75dfb56c460cb3 Mon Sep 17 00:00:00 2001
From: Ben Wolsieffer <Ben.Wolsieffer(a)hefring.com>
Date: Thu, 14 Sep 2023 12:30:20 -0400
Subject: [PATCH] proc: nommu: /proc/<pid>/maps: release mmap read lock
The no-MMU implementation of /proc/<pid>/map doesn't normally release
the mmap read lock, because it uses !IS_ERR_OR_NULL(_vml) to determine
whether to release the lock. Since _vml is NULL when the end of the
mappings is reached, the lock is not released.
Reading /proc/1/maps twice doesn't cause a hang because it only
takes the read lock, which can be taken multiple times and therefore
doesn't show any problem if the lock isn't released. Instead, you need
to perform some operation that attempts to take the write lock after
reading /proc/<pid>/maps. To actually reproduce the bug, compile the
following code as 'proc_maps_bug':
#include <stdio.h>
#include <unistd.h>
#include <sys/mman.h>
int main(int argc, char *argv[]) {
void *buf;
sleep(1);
buf = mmap(NULL, 4096, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
puts("mmap returned");
return 0;
}
Then, run:
./proc_maps_bug &; cat /proc/$!/maps; fg
Without this patch, mmap() will hang and the command will never
complete.
This code was incorrectly adapted from the MMU implementation, which at
the time released the lock in m_next() before returning the last entry.
The MMU implementation has diverged further from the no-MMU version since
then, so this patch brings their locking and error handling into sync,
fixing the bug and hopefully avoiding similar issues in the future.
Link: https://lkml.kernel.org/r/20230914163019.4050530-2-ben.wolsieffer@hefring.c…
Fixes: 47fecca15c09 ("fs/proc/task_nommu.c: don't use priv->task->mm")
Signed-off-by: Ben Wolsieffer <ben.wolsieffer(a)hefring.com>
Acked-by: Oleg Nesterov <oleg(a)redhat.com>
Cc: Giulio Benetti <giulio.benetti(a)benettiengineering.com>
Cc: Greg Ungerer <gerg(a)uclinux.org>
Cc: <stable(a)vger.kernel.org>
Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org>
diff --git a/fs/proc/task_nommu.c b/fs/proc/task_nommu.c
index a8ac0dd8041e..bc2e843f4810 100644
--- a/fs/proc/task_nommu.c
+++ b/fs/proc/task_nommu.c
@@ -192,11 +192,16 @@ static void *m_start(struct seq_file *m, loff_t *pos)
return ERR_PTR(-ESRCH);
mm = priv->mm;
- if (!mm || !mmget_not_zero(mm))
+ if (!mm || !mmget_not_zero(mm)) {
+ put_task_struct(priv->task);
+ priv->task = NULL;
return NULL;
+ }
if (mmap_read_lock_killable(mm)) {
mmput(mm);
+ put_task_struct(priv->task);
+ priv->task = NULL;
return ERR_PTR(-EINTR);
}
@@ -205,23 +210,21 @@ static void *m_start(struct seq_file *m, loff_t *pos)
if (vma)
return vma;
- mmap_read_unlock(mm);
- mmput(mm);
return NULL;
}
-static void m_stop(struct seq_file *m, void *_vml)
+static void m_stop(struct seq_file *m, void *v)
{
struct proc_maps_private *priv = m->private;
+ struct mm_struct *mm = priv->mm;
- if (!IS_ERR_OR_NULL(_vml)) {
- mmap_read_unlock(priv->mm);
- mmput(priv->mm);
- }
- if (priv->task) {
- put_task_struct(priv->task);
- priv->task = NULL;
- }
+ if (!priv->task)
+ return;
+
+ mmap_read_unlock(mm);
+ mmput(mm);
+ put_task_struct(priv->task);
+ priv->task = NULL;
}
static void *m_next(struct seq_file *m, void *_p, loff_t *pos)
The patch below does not apply to the 4.19-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(a)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-4.19.y
git checkout FETCH_HEAD
git cherry-pick -x 578d7699e5c2add8c2e9549d9d75dfb56c460cb3
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2023100408-swab-depict-d818@gregkh' --subject-prefix 'PATCH 4.19.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 578d7699e5c2add8c2e9549d9d75dfb56c460cb3 Mon Sep 17 00:00:00 2001
From: Ben Wolsieffer <Ben.Wolsieffer(a)hefring.com>
Date: Thu, 14 Sep 2023 12:30:20 -0400
Subject: [PATCH] proc: nommu: /proc/<pid>/maps: release mmap read lock
The no-MMU implementation of /proc/<pid>/map doesn't normally release
the mmap read lock, because it uses !IS_ERR_OR_NULL(_vml) to determine
whether to release the lock. Since _vml is NULL when the end of the
mappings is reached, the lock is not released.
Reading /proc/1/maps twice doesn't cause a hang because it only
takes the read lock, which can be taken multiple times and therefore
doesn't show any problem if the lock isn't released. Instead, you need
to perform some operation that attempts to take the write lock after
reading /proc/<pid>/maps. To actually reproduce the bug, compile the
following code as 'proc_maps_bug':
#include <stdio.h>
#include <unistd.h>
#include <sys/mman.h>
int main(int argc, char *argv[]) {
void *buf;
sleep(1);
buf = mmap(NULL, 4096, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
puts("mmap returned");
return 0;
}
Then, run:
./proc_maps_bug &; cat /proc/$!/maps; fg
Without this patch, mmap() will hang and the command will never
complete.
This code was incorrectly adapted from the MMU implementation, which at
the time released the lock in m_next() before returning the last entry.
The MMU implementation has diverged further from the no-MMU version since
then, so this patch brings their locking and error handling into sync,
fixing the bug and hopefully avoiding similar issues in the future.
Link: https://lkml.kernel.org/r/20230914163019.4050530-2-ben.wolsieffer@hefring.c…
Fixes: 47fecca15c09 ("fs/proc/task_nommu.c: don't use priv->task->mm")
Signed-off-by: Ben Wolsieffer <ben.wolsieffer(a)hefring.com>
Acked-by: Oleg Nesterov <oleg(a)redhat.com>
Cc: Giulio Benetti <giulio.benetti(a)benettiengineering.com>
Cc: Greg Ungerer <gerg(a)uclinux.org>
Cc: <stable(a)vger.kernel.org>
Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org>
diff --git a/fs/proc/task_nommu.c b/fs/proc/task_nommu.c
index a8ac0dd8041e..bc2e843f4810 100644
--- a/fs/proc/task_nommu.c
+++ b/fs/proc/task_nommu.c
@@ -192,11 +192,16 @@ static void *m_start(struct seq_file *m, loff_t *pos)
return ERR_PTR(-ESRCH);
mm = priv->mm;
- if (!mm || !mmget_not_zero(mm))
+ if (!mm || !mmget_not_zero(mm)) {
+ put_task_struct(priv->task);
+ priv->task = NULL;
return NULL;
+ }
if (mmap_read_lock_killable(mm)) {
mmput(mm);
+ put_task_struct(priv->task);
+ priv->task = NULL;
return ERR_PTR(-EINTR);
}
@@ -205,23 +210,21 @@ static void *m_start(struct seq_file *m, loff_t *pos)
if (vma)
return vma;
- mmap_read_unlock(mm);
- mmput(mm);
return NULL;
}
-static void m_stop(struct seq_file *m, void *_vml)
+static void m_stop(struct seq_file *m, void *v)
{
struct proc_maps_private *priv = m->private;
+ struct mm_struct *mm = priv->mm;
- if (!IS_ERR_OR_NULL(_vml)) {
- mmap_read_unlock(priv->mm);
- mmput(priv->mm);
- }
- if (priv->task) {
- put_task_struct(priv->task);
- priv->task = NULL;
- }
+ if (!priv->task)
+ return;
+
+ mmap_read_unlock(mm);
+ mmput(mm);
+ put_task_struct(priv->task);
+ priv->task = NULL;
}
static void *m_next(struct seq_file *m, void *_p, loff_t *pos)
The patch below does not apply to the 5.4-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(a)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-5.4.y
git checkout FETCH_HEAD
git cherry-pick -x 578d7699e5c2add8c2e9549d9d75dfb56c460cb3
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2023100406-component-isolating-b700@gregkh' --subject-prefix 'PATCH 5.4.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 578d7699e5c2add8c2e9549d9d75dfb56c460cb3 Mon Sep 17 00:00:00 2001
From: Ben Wolsieffer <Ben.Wolsieffer(a)hefring.com>
Date: Thu, 14 Sep 2023 12:30:20 -0400
Subject: [PATCH] proc: nommu: /proc/<pid>/maps: release mmap read lock
The no-MMU implementation of /proc/<pid>/map doesn't normally release
the mmap read lock, because it uses !IS_ERR_OR_NULL(_vml) to determine
whether to release the lock. Since _vml is NULL when the end of the
mappings is reached, the lock is not released.
Reading /proc/1/maps twice doesn't cause a hang because it only
takes the read lock, which can be taken multiple times and therefore
doesn't show any problem if the lock isn't released. Instead, you need
to perform some operation that attempts to take the write lock after
reading /proc/<pid>/maps. To actually reproduce the bug, compile the
following code as 'proc_maps_bug':
#include <stdio.h>
#include <unistd.h>
#include <sys/mman.h>
int main(int argc, char *argv[]) {
void *buf;
sleep(1);
buf = mmap(NULL, 4096, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
puts("mmap returned");
return 0;
}
Then, run:
./proc_maps_bug &; cat /proc/$!/maps; fg
Without this patch, mmap() will hang and the command will never
complete.
This code was incorrectly adapted from the MMU implementation, which at
the time released the lock in m_next() before returning the last entry.
The MMU implementation has diverged further from the no-MMU version since
then, so this patch brings their locking and error handling into sync,
fixing the bug and hopefully avoiding similar issues in the future.
Link: https://lkml.kernel.org/r/20230914163019.4050530-2-ben.wolsieffer@hefring.c…
Fixes: 47fecca15c09 ("fs/proc/task_nommu.c: don't use priv->task->mm")
Signed-off-by: Ben Wolsieffer <ben.wolsieffer(a)hefring.com>
Acked-by: Oleg Nesterov <oleg(a)redhat.com>
Cc: Giulio Benetti <giulio.benetti(a)benettiengineering.com>
Cc: Greg Ungerer <gerg(a)uclinux.org>
Cc: <stable(a)vger.kernel.org>
Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org>
diff --git a/fs/proc/task_nommu.c b/fs/proc/task_nommu.c
index a8ac0dd8041e..bc2e843f4810 100644
--- a/fs/proc/task_nommu.c
+++ b/fs/proc/task_nommu.c
@@ -192,11 +192,16 @@ static void *m_start(struct seq_file *m, loff_t *pos)
return ERR_PTR(-ESRCH);
mm = priv->mm;
- if (!mm || !mmget_not_zero(mm))
+ if (!mm || !mmget_not_zero(mm)) {
+ put_task_struct(priv->task);
+ priv->task = NULL;
return NULL;
+ }
if (mmap_read_lock_killable(mm)) {
mmput(mm);
+ put_task_struct(priv->task);
+ priv->task = NULL;
return ERR_PTR(-EINTR);
}
@@ -205,23 +210,21 @@ static void *m_start(struct seq_file *m, loff_t *pos)
if (vma)
return vma;
- mmap_read_unlock(mm);
- mmput(mm);
return NULL;
}
-static void m_stop(struct seq_file *m, void *_vml)
+static void m_stop(struct seq_file *m, void *v)
{
struct proc_maps_private *priv = m->private;
+ struct mm_struct *mm = priv->mm;
- if (!IS_ERR_OR_NULL(_vml)) {
- mmap_read_unlock(priv->mm);
- mmput(priv->mm);
- }
- if (priv->task) {
- put_task_struct(priv->task);
- priv->task = NULL;
- }
+ if (!priv->task)
+ return;
+
+ mmap_read_unlock(mm);
+ mmput(mm);
+ put_task_struct(priv->task);
+ priv->task = NULL;
}
static void *m_next(struct seq_file *m, void *_p, loff_t *pos)
The patch below does not apply to the 6.5-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(a)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-6.5.y
git checkout FETCH_HEAD
git cherry-pick -x e765886249c533e1bb5cbc3cd741bad677417312
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2023100450-shone-catchy-89d1@gregkh' --subject-prefix 'PATCH 6.5.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From e765886249c533e1bb5cbc3cd741bad677417312 Mon Sep 17 00:00:00 2001
From: Sameer Pujar <spujar(a)nvidia.com>
Date: Thu, 7 Sep 2023 20:32:25 +0530
Subject: [PATCH] ASoC: tegra: Fix redundant PLLA and PLLA_OUT0 updates
Tegra audio graph card has many DAI links which connects internal
AHUB modules and external audio codecs. Since these are DPCM links,
hw_params() call in the machine driver happens for each connected
BE link and PLLA is updated every time. This is not really needed
for all links as only I/O link DAIs derive respective clocks from
PLLA_OUT0 and thus from PLLA. Hence add checks to limit the clock
updates to DAIs over I/O links.
This found to be fixing a DMIC clock discrepancy which is suspected
to happen because of back to back quick PLLA and PLLA_OUT0 rate
updates. This was observed on Jetson TX2 platform where DMIC clock
ended up with unexpected value.
Fixes: 202e2f774543 ("ASoC: tegra: Add audio graph based card driver")
Cc: stable(a)vger.kernel.org
Signed-off-by: Sameer Pujar <spujar(a)nvidia.com>
Link: https://lore.kernel.org/r/1694098945-32760-3-git-send-email-spujar@nvidia.c…
Signed-off-by: Mark Brown <broonie(a)kernel.org>
diff --git a/sound/soc/tegra/tegra_audio_graph_card.c b/sound/soc/tegra/tegra_audio_graph_card.c
index 1f2c5018bf5a..4737e776d383 100644
--- a/sound/soc/tegra/tegra_audio_graph_card.c
+++ b/sound/soc/tegra/tegra_audio_graph_card.c
@@ -10,6 +10,7 @@
#include <linux/platform_device.h>
#include <sound/graph_card.h>
#include <sound/pcm_params.h>
+#include <sound/soc-dai.h>
#define MAX_PLLA_OUT0_DIV 128
@@ -44,6 +45,21 @@ struct tegra_audio_cdata {
unsigned int plla_out0_rates[NUM_RATE_TYPE];
};
+static bool need_clk_update(struct snd_soc_dai *dai)
+{
+ if (snd_soc_dai_is_dummy(dai) ||
+ !dai->driver->ops ||
+ !dai->driver->name)
+ return false;
+
+ if (strstr(dai->driver->name, "I2S") ||
+ strstr(dai->driver->name, "DMIC") ||
+ strstr(dai->driver->name, "DSPK"))
+ return true;
+
+ return false;
+}
+
/* Setup PLL clock as per the given sample rate */
static int tegra_audio_graph_update_pll(struct snd_pcm_substream *substream,
struct snd_pcm_hw_params *params)
@@ -140,19 +156,7 @@ static int tegra_audio_graph_hw_params(struct snd_pcm_substream *substream,
struct snd_soc_dai *cpu_dai = asoc_rtd_to_cpu(rtd, 0);
int err;
- /*
- * This gets called for each DAI link (FE or BE) when DPCM is used.
- * We may not want to update PLLA rate for each call. So PLLA update
- * must be restricted to external I/O links (I2S, DMIC or DSPK) since
- * they actually depend on it. I/O modules update their clocks in
- * hw_param() of their respective component driver and PLLA rate
- * update here helps them to derive appropriate rates.
- *
- * TODO: When more HW accelerators get added (like sample rate
- * converter, volume gain controller etc., which don't really
- * depend on PLLA) we need a better way to filter here.
- */
- if (cpu_dai->driver->ops && rtd->dai_link->no_pcm) {
+ if (need_clk_update(cpu_dai)) {
err = tegra_audio_graph_update_pll(substream, params);
if (err)
return err;
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