* [to-be-updated] mm-vma-use-vma_start_write_killable-in-vma-operations.patch removed from -mm tree
@ 2026-03-27 23:04 Andrew Morton
0 siblings, 0 replies; 2+ messages in thread
From: Andrew Morton @ 2026-03-27 23:04 UTC (permalink / raw)
To: mm-commits, surenb, akpm
The quilt patch titled
Subject: mm/vma: use vma_start_write_killable() in vma operations
has been removed from the -mm tree. Its filename was
mm-vma-use-vma_start_write_killable-in-vma-operations.patch
This patch was dropped because an updated version will be issued
------------------------------------------------------
From: Suren Baghdasaryan <surenb@google.com>
Subject: mm/vma: use vma_start_write_killable() in vma operations
Date: Thu, 26 Mar 2026 01:08:34 -0700
Replace vma_start_write() with vma_start_write_killable(), improving
reaction time to the kill signal.
Replace vma_start_write() calls when we operate on VMAs.
In a number of places we now lock VMA earlier than before to avoid
doing work and undoing it later if a fatal signal is pending. This
is safe because the moves are happening within sections where we
already hold the mmap_write_lock, so the moves do not change the
locking order relative to other kernel locks.
Link: https://lkml.kernel.org/r/20260326080836.695207-5-surenb@google.com
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Suggested-by: Matthew Wilcox <willy@infradead.org>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Barry Song <baohua@kernel.org>
Cc: Byungchul Park <byungchul@sk.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: "Christophe Leroy (CS GROUP)" <chleroy@kernel.org>
Cc: Claudio Imbrenda <imbrenda@linux.ibm.com>
Cc: David Hildenbrand <david@kernel.org>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Cc: Gregory Price <gourry@gourry.net>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: "Huang, Ying" <ying.huang@linux.alibaba.com>
Cc: Jann Horn <jannh@google.com>
Cc: Janosch Frank <frankja@linux.ibm.com>
Cc: Joshua Hahn <joshua.hahnjy@gmail.com>
Cc: Kees Cook <kees@kernel.org>
Cc: Lance Yang <lance.yang@linux.dev>
Cc: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Lorenzo Stoakes (Oracle) <ljs@kernel.org>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Matthew Brost <matthew.brost@intel.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Nico Pache <npache@redhat.com>
Cc: Pedro Falcato <pfalcato@suse.de>
Cc: Rakie Kim <rakie.kim@sk.com>
Cc: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---
mm/vma.c | 130 +++++++++++++++++++++++++++++++++++-------------
mm/vma_exec.c | 6 +-
2 files changed, 101 insertions(+), 35 deletions(-)
--- a/mm/vma.c~mm-vma-use-vma_start_write_killable-in-vma-operations
+++ a/mm/vma.c
@@ -524,6 +524,17 @@ __split_vma(struct vma_iterator *vmi, st
new->vm_pgoff += ((addr - vma->vm_start) >> PAGE_SHIFT);
}
+ /*
+ * Lock VMAs before cloning to avoid extra work if fatal signal
+ * is pending.
+ */
+ err = vma_start_write_killable(vma);
+ if (err)
+ goto out_free_vma;
+ err = vma_start_write_killable(new);
+ if (err)
+ goto out_free_vma;
+
err = -ENOMEM;
vma_iter_config(vmi, new->vm_start, new->vm_end);
if (vma_iter_prealloc(vmi, new))
@@ -543,9 +554,6 @@ __split_vma(struct vma_iterator *vmi, st
if (new->vm_ops && new->vm_ops->open)
new->vm_ops->open(new);
- vma_start_write(vma);
- vma_start_write(new);
-
init_vma_prep(&vp, vma);
vp.insert = new;
vma_prepare(&vp);
@@ -900,12 +908,22 @@ static __must_check struct vm_area_struc
}
/* No matter what happens, we will be adjusting middle. */
- vma_start_write(middle);
+ err = vma_start_write_killable(middle);
+ if (err) {
+ /* Ensure error propagates. */
+ vmg->give_up_on_oom = false;
+ goto abort;
+ }
if (merge_right) {
vma_flags_t next_sticky;
- vma_start_write(next);
+ err = vma_start_write_killable(next);
+ if (err) {
+ /* Ensure error propagates. */
+ vmg->give_up_on_oom = false;
+ goto abort;
+ }
vmg->target = next;
next_sticky = vma_flags_and_mask(&next->flags, VMA_STICKY_FLAGS);
vma_flags_set_mask(&sticky_flags, next_sticky);
@@ -914,7 +932,12 @@ static __must_check struct vm_area_struc
if (merge_left) {
vma_flags_t prev_sticky;
- vma_start_write(prev);
+ err = vma_start_write_killable(prev);
+ if (err) {
+ /* Ensure error propagates. */
+ vmg->give_up_on_oom = false;
+ goto abort;
+ }
vmg->target = prev;
prev_sticky = vma_flags_and_mask(&prev->flags, VMA_STICKY_FLAGS);
@@ -1170,10 +1193,12 @@ int vma_expand(struct vma_merge_struct *
vma_flags_t sticky_flags =
vma_flags_and_mask(&vmg->vma_flags, VMA_STICKY_FLAGS);
vma_flags_t target_sticky;
- int err = 0;
+ int err;
mmap_assert_write_locked(vmg->mm);
- vma_start_write(target);
+ err = vma_start_write_killable(target);
+ if (err)
+ return err;
target_sticky = vma_flags_and_mask(&target->flags, VMA_STICKY_FLAGS);
@@ -1201,6 +1226,13 @@ int vma_expand(struct vma_merge_struct *
* we don't need to account for vmg->give_up_on_mm here.
*/
if (remove_next) {
+ /*
+ * Lock the VMA early to avoid extra work if fatal signal
+ * is pending.
+ */
+ err = vma_start_write_killable(next);
+ if (err)
+ return err;
err = dup_anon_vma(target, next, &anon_dup);
if (err)
return err;
@@ -1214,7 +1246,6 @@ int vma_expand(struct vma_merge_struct *
if (remove_next) {
vma_flags_t next_sticky;
- vma_start_write(next);
vmg->__remove_next = true;
next_sticky = vma_flags_and_mask(&next->flags, VMA_STICKY_FLAGS);
@@ -1252,9 +1283,14 @@ int vma_shrink(struct vma_iterator *vmi,
unsigned long start, unsigned long end, pgoff_t pgoff)
{
struct vma_prepare vp;
+ int err;
WARN_ON((vma->vm_start != start) && (vma->vm_end != end));
+ err = vma_start_write_killable(vma);
+ if (err)
+ return err;
+
if (vma->vm_start < start)
vma_iter_config(vmi, vma->vm_start, start);
else
@@ -1263,8 +1299,6 @@ int vma_shrink(struct vma_iterator *vmi,
if (vma_iter_prealloc(vmi, NULL))
return -ENOMEM;
- vma_start_write(vma);
-
init_vma_prep(&vp, vma);
vma_prepare(&vp);
vma_adjust_trans_huge(vma, start, end, NULL);
@@ -1453,7 +1487,9 @@ static int vms_gather_munmap_vmas(struct
if (error)
goto end_split_failed;
}
- vma_start_write(next);
+ error = vma_start_write_killable(next);
+ if (error)
+ goto munmap_gather_failed;
mas_set(mas_detach, vms->vma_count++);
error = mas_store_gfp(mas_detach, next, GFP_KERNEL);
if (error)
@@ -1848,12 +1884,16 @@ static void vma_link_file(struct vm_area
static int vma_link(struct mm_struct *mm, struct vm_area_struct *vma)
{
VMA_ITERATOR(vmi, mm, 0);
+ int err;
+
+ err = vma_start_write_killable(vma);
+ if (err)
+ return err;
vma_iter_config(&vmi, vma->vm_start, vma->vm_end);
if (vma_iter_prealloc(&vmi, vma))
return -ENOMEM;
- vma_start_write(vma);
vma_iter_store_new(&vmi, vma);
vma_link_file(vma, /* hold_rmap_lock= */false);
mm->map_count++;
@@ -2239,9 +2279,8 @@ int mm_take_all_locks(struct mm_struct *
* is reached.
*/
for_each_vma(vmi, vma) {
- if (signal_pending(current))
+ if (signal_pending(current) || vma_start_write_killable(vma))
goto out_unlock;
- vma_start_write(vma);
}
vma_iter_init(&vmi, mm, 0);
@@ -2540,8 +2579,8 @@ static int __mmap_new_vma(struct mmap_st
struct mmap_action *action)
{
struct vma_iterator *vmi = map->vmi;
- int error = 0;
struct vm_area_struct *vma;
+ int error;
/*
* Determine the object being mapped and call the appropriate
@@ -2552,6 +2591,14 @@ static int __mmap_new_vma(struct mmap_st
if (!vma)
return -ENOMEM;
+ /*
+ * Lock the VMA early to avoid extra work if fatal signal
+ * is pending.
+ */
+ error = vma_start_write_killable(vma);
+ if (error)
+ goto free_vma;
+
vma_iter_config(vmi, map->addr, map->end);
vma_set_range(vma, map->addr, map->end, map->pgoff);
vma->flags = map->vma_flags;
@@ -2582,8 +2629,6 @@ static int __mmap_new_vma(struct mmap_st
WARN_ON_ONCE(!arch_validate_flags(map->vm_flags));
#endif
- /* Lock the VMA since it is modified after insertion into VMA tree */
- vma_start_write(vma);
vma_iter_store_new(vmi, vma);
map->mm->map_count++;
vma_link_file(vma, action->hide_from_rmap_until_complete);
@@ -2878,6 +2923,7 @@ int do_brk_flags(struct vma_iterator *vm
unsigned long addr, unsigned long len, vma_flags_t vma_flags)
{
struct mm_struct *mm = current->mm;
+ int err;
/*
* Check against address space limits by the changed size
@@ -2910,24 +2956,33 @@ int do_brk_flags(struct vma_iterator *vm
if (vma_merge_new_range(&vmg))
goto out;
- else if (vmg_nomem(&vmg))
+ if (vmg_nomem(&vmg)) {
+ err = -ENOMEM;
goto unacct_fail;
+ }
}
if (vma)
vma_iter_next_range(vmi);
/* create a vma struct for an anonymous mapping */
vma = vm_area_alloc(mm);
- if (!vma)
+ if (!vma) {
+ err = -ENOMEM;
goto unacct_fail;
+ }
vma_set_anonymous(vma);
vma_set_range(vma, addr, addr + len, addr >> PAGE_SHIFT);
vma->flags = vma_flags;
vma->vm_page_prot = vm_get_page_prot(vma_flags_to_legacy(vma_flags));
- vma_start_write(vma);
- if (vma_iter_store_gfp(vmi, vma, GFP_KERNEL))
+ if (vma_start_write_killable(vma)) {
+ err = -EINTR;
+ goto vma_lock_fail;
+ }
+ if (vma_iter_store_gfp(vmi, vma, GFP_KERNEL)) {
+ err = -ENOMEM;
goto mas_store_fail;
+ }
mm->map_count++;
validate_mm(mm);
@@ -2942,10 +2997,11 @@ out:
return 0;
mas_store_fail:
+vma_lock_fail:
vm_area_free(vma);
unacct_fail:
vm_unacct_memory(len >> PAGE_SHIFT);
- return -ENOMEM;
+ return err;
}
/**
@@ -3112,8 +3168,8 @@ int expand_upwards(struct vm_area_struct
struct mm_struct *mm = vma->vm_mm;
struct vm_area_struct *next;
unsigned long gap_addr;
- int error = 0;
VMA_ITERATOR(vmi, mm, vma->vm_start);
+ int error;
if (!vma_test(vma, VMA_GROWSUP_BIT))
return -EFAULT;
@@ -3149,12 +3205,14 @@ int expand_upwards(struct vm_area_struct
/* We must make sure the anon_vma is allocated. */
if (unlikely(anon_vma_prepare(vma))) {
- vma_iter_free(&vmi);
- return -ENOMEM;
+ error = -ENOMEM;
+ goto vma_prep_fail;
}
/* Lock the VMA before expanding to prevent concurrent page faults */
- vma_start_write(vma);
+ error = vma_start_write_killable(vma);
+ if (error)
+ goto vma_lock_fail;
/* We update the anon VMA tree. */
anon_vma_lock_write(vma->anon_vma);
@@ -3183,8 +3241,10 @@ int expand_upwards(struct vm_area_struct
}
}
anon_vma_unlock_write(vma->anon_vma);
- vma_iter_free(&vmi);
validate_mm(mm);
+vma_lock_fail:
+vma_prep_fail:
+ vma_iter_free(&vmi);
return error;
}
#endif /* CONFIG_STACK_GROWSUP */
@@ -3197,8 +3257,8 @@ int expand_downwards(struct vm_area_stru
{
struct mm_struct *mm = vma->vm_mm;
struct vm_area_struct *prev;
- int error = 0;
VMA_ITERATOR(vmi, mm, vma->vm_start);
+ int error;
if (!vma_test(vma, VMA_GROWSDOWN_BIT))
return -EFAULT;
@@ -3228,12 +3288,14 @@ int expand_downwards(struct vm_area_stru
/* We must make sure the anon_vma is allocated. */
if (unlikely(anon_vma_prepare(vma))) {
- vma_iter_free(&vmi);
- return -ENOMEM;
+ error = -ENOMEM;
+ goto vma_prep_fail;
}
/* Lock the VMA before expanding to prevent concurrent page faults */
- vma_start_write(vma);
+ error = vma_start_write_killable(vma);
+ if (error)
+ goto vma_lock_fail;
/* We update the anon VMA tree. */
anon_vma_lock_write(vma->anon_vma);
@@ -3263,8 +3325,10 @@ int expand_downwards(struct vm_area_stru
}
}
anon_vma_unlock_write(vma->anon_vma);
- vma_iter_free(&vmi);
validate_mm(mm);
+vma_lock_fail:
+vma_prep_fail:
+ vma_iter_free(&vmi);
return error;
}
--- a/mm/vma_exec.c~mm-vma-use-vma_start_write_killable-in-vma-operations
+++ a/mm/vma_exec.c
@@ -41,6 +41,7 @@ int relocate_vma_down(struct vm_area_str
struct vm_area_struct *next;
struct mmu_gather tlb;
PAGETABLE_MOVE(pmc, vma, vma, old_start, new_start, length);
+ int err;
BUG_ON(new_start > new_end);
@@ -56,8 +57,9 @@ int relocate_vma_down(struct vm_area_str
* cover the whole range: [new_start, old_end)
*/
vmg.target = vma;
- if (vma_expand(&vmg))
- return -ENOMEM;
+ err = vma_expand(&vmg);
+ if (err)
+ return err;
/*
* move the page tables downwards, on failure we rely on
_
Patches currently in -mm which might be from surenb@google.com are
a.patch
mm-use-vma_start_write_killable-in-process_vma_walk_lock.patch
kvm-ppc-use-vma_start_write_killable-in-kvmppc_memslot_page_merge.patch
mm-vmscan-prevent-mglru-reclaim-from-pinning-address-space.patch
^ permalink raw reply [flat|nested] 2+ messages in thread
* [to-be-updated] mm-vma-use-vma_start_write_killable-in-vma-operations.patch removed from -mm tree
@ 2026-03-31 18:29 Andrew Morton
0 siblings, 0 replies; 2+ messages in thread
From: Andrew Morton @ 2026-03-31 18:29 UTC (permalink / raw)
To: mm-commits, surenb, akpm
The quilt patch titled
Subject: mm/vma: use vma_start_write_killable() in vma operations
has been removed from the -mm tree. Its filename was
mm-vma-use-vma_start_write_killable-in-vma-operations.patch
This patch was dropped because an updated version will be issued
------------------------------------------------------
From: Suren Baghdasaryan <surenb@google.com>
Subject: mm/vma: use vma_start_write_killable() in vma operations
Date: Fri, 27 Mar 2026 13:54:55 -0700
Replace vma_start_write() with vma_start_write_killable(), improving
reaction time to the kill signal. Replace vma_start_write() calls when we
operate on VMAs.
To propagate errors from vma_merge_existing_range() and vma_expand() we
fake an ENOMEM error when we fail due to a pending fatal signal. This is
a temporary workaround. Fixing this requires some refactoring and will be
done separately in the future.
In a number of places we now lock VMA earlier than before to avoid doing
work and undoing it later if a fatal signal is pending. This is safe
because the moves are happening within sections where we already hold the
mmap_write_lock, so the moves do not change the locking order relative to
other kernel locks.
Link: https://lkml.kernel.org/r/20260327205457.604224-5-surenb@google.com
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Suggested-by: Matthew Wilcox <willy@infradead.org>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Barry Song <baohua@kernel.org>
Cc: Byungchul Park <byungchul@sk.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Claudio Imbrenda <imbrenda@linux.ibm.com>
Cc: David Hildenbrand <david@kernel.org>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Cc: Gregory Price <gourry@gourry.net>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: "Huang, Ying" <ying.huang@linux.alibaba.com>
Cc: Jann Horn <jannh@google.com>
Cc: Janosch Frank <frankja@linux.ibm.com>
Cc: Joshua Hahn <joshua.hahnjy@gmail.com>
Cc: Kees Cook <kees@kernel.org>
Cc: Lance Yang <lance.yang@linux.dev>
Cc: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Lorenzo Stoakes (Oracle) <ljs@kernel.org>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Matthew Brost <matthew.brost@intel.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Nico Pache <npache@redhat.com>
Cc: Pedro Falcato <pfalcato@suse.de>
Cc: Rakie Kim <rakie.kim@sk.com>
Cc: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---
mm/vma.c | 146 +++++++++++++++++++++++++++++++++++++-----------
mm/vma_exec.c | 6 +
2 files changed, 117 insertions(+), 35 deletions(-)
--- a/mm/vma.c~mm-vma-use-vma_start_write_killable-in-vma-operations
+++ a/mm/vma.c
@@ -524,6 +524,21 @@ __split_vma(struct vma_iterator *vmi, st
new->vm_pgoff += ((addr - vma->vm_start) >> PAGE_SHIFT);
}
+ /*
+ * Lock VMAs before cloning to avoid extra work if fatal signal
+ * is pending.
+ */
+ err = vma_start_write_killable(vma);
+ if (err)
+ goto out_free_vma;
+ /*
+ * Locking a new detached VMA will always succeed but it's just a
+ * detail of the current implementation, so handle it all the same.
+ */
+ err = vma_start_write_killable(new);
+ if (err)
+ goto out_free_vma;
+
err = -ENOMEM;
vma_iter_config(vmi, new->vm_start, new->vm_end);
if (vma_iter_prealloc(vmi, new))
@@ -543,9 +558,6 @@ __split_vma(struct vma_iterator *vmi, st
if (new->vm_ops && new->vm_ops->open)
new->vm_ops->open(new);
- vma_start_write(vma);
- vma_start_write(new);
-
init_vma_prep(&vp, vma);
vp.insert = new;
vma_prepare(&vp);
@@ -900,12 +912,22 @@ static __must_check struct vm_area_struc
}
/* No matter what happens, we will be adjusting middle. */
- vma_start_write(middle);
+ err = vma_start_write_killable(middle);
+ if (err) {
+ /* Ensure error propagates. */
+ vmg->give_up_on_oom = false;
+ goto abort;
+ }
if (merge_right) {
vma_flags_t next_sticky;
- vma_start_write(next);
+ err = vma_start_write_killable(next);
+ if (err) {
+ /* Ensure error propagates. */
+ vmg->give_up_on_oom = false;
+ goto abort;
+ }
vmg->target = next;
next_sticky = vma_flags_and_mask(&next->flags, VMA_STICKY_FLAGS);
vma_flags_set_mask(&sticky_flags, next_sticky);
@@ -914,7 +936,12 @@ static __must_check struct vm_area_struc
if (merge_left) {
vma_flags_t prev_sticky;
- vma_start_write(prev);
+ err = vma_start_write_killable(prev);
+ if (err) {
+ /* Ensure error propagates. */
+ vmg->give_up_on_oom = false;
+ goto abort;
+ }
vmg->target = prev;
prev_sticky = vma_flags_and_mask(&prev->flags, VMA_STICKY_FLAGS);
@@ -1170,10 +1197,18 @@ int vma_expand(struct vma_merge_struct *
vma_flags_t sticky_flags =
vma_flags_and_mask(&vmg->vma_flags, VMA_STICKY_FLAGS);
vma_flags_t target_sticky;
- int err = 0;
+ int err;
mmap_assert_write_locked(vmg->mm);
- vma_start_write(target);
+ err = vma_start_write_killable(target);
+ if (err) {
+ /*
+ * Override VMA_MERGE_NOMERGE to prevent callers from
+ * falling back to a new VMA allocation.
+ */
+ vmg->state = VMA_MERGE_ERROR_NOMEM;
+ return err;
+ }
target_sticky = vma_flags_and_mask(&target->flags, VMA_STICKY_FLAGS);
@@ -1201,6 +1236,19 @@ int vma_expand(struct vma_merge_struct *
* we don't need to account for vmg->give_up_on_mm here.
*/
if (remove_next) {
+ /*
+ * Lock the VMA early to avoid extra work if fatal signal
+ * is pending.
+ */
+ err = vma_start_write_killable(next);
+ if (err) {
+ /*
+ * Override VMA_MERGE_NOMERGE to prevent callers from
+ * falling back to a new VMA allocation.
+ */
+ vmg->state = VMA_MERGE_ERROR_NOMEM;
+ return err;
+ }
err = dup_anon_vma(target, next, &anon_dup);
if (err)
return err;
@@ -1214,7 +1262,6 @@ int vma_expand(struct vma_merge_struct *
if (remove_next) {
vma_flags_t next_sticky;
- vma_start_write(next);
vmg->__remove_next = true;
next_sticky = vma_flags_and_mask(&next->flags, VMA_STICKY_FLAGS);
@@ -1252,9 +1299,14 @@ int vma_shrink(struct vma_iterator *vmi,
unsigned long start, unsigned long end, pgoff_t pgoff)
{
struct vma_prepare vp;
+ int err;
WARN_ON((vma->vm_start != start) && (vma->vm_end != end));
+ err = vma_start_write_killable(vma);
+ if (err)
+ return err;
+
if (vma->vm_start < start)
vma_iter_config(vmi, vma->vm_start, start);
else
@@ -1263,8 +1315,6 @@ int vma_shrink(struct vma_iterator *vmi,
if (vma_iter_prealloc(vmi, NULL))
return -ENOMEM;
- vma_start_write(vma);
-
init_vma_prep(&vp, vma);
vma_prepare(&vp);
vma_adjust_trans_huge(vma, start, end, NULL);
@@ -1453,7 +1503,9 @@ static int vms_gather_munmap_vmas(struct
if (error)
goto end_split_failed;
}
- vma_start_write(next);
+ error = vma_start_write_killable(next);
+ if (error)
+ goto munmap_gather_failed;
mas_set(mas_detach, vms->vma_count++);
error = mas_store_gfp(mas_detach, next, GFP_KERNEL);
if (error)
@@ -1848,12 +1900,16 @@ static void vma_link_file(struct vm_area
static int vma_link(struct mm_struct *mm, struct vm_area_struct *vma)
{
VMA_ITERATOR(vmi, mm, 0);
+ int err;
+
+ err = vma_start_write_killable(vma);
+ if (err)
+ return err;
vma_iter_config(&vmi, vma->vm_start, vma->vm_end);
if (vma_iter_prealloc(&vmi, vma))
return -ENOMEM;
- vma_start_write(vma);
vma_iter_store_new(&vmi, vma);
vma_link_file(vma, /* hold_rmap_lock= */false);
mm->map_count++;
@@ -2239,9 +2295,8 @@ int mm_take_all_locks(struct mm_struct *
* is reached.
*/
for_each_vma(vmi, vma) {
- if (signal_pending(current))
+ if (signal_pending(current) || vma_start_write_killable(vma))
goto out_unlock;
- vma_start_write(vma);
}
vma_iter_init(&vmi, mm, 0);
@@ -2540,8 +2595,8 @@ static int __mmap_new_vma(struct mmap_st
struct mmap_action *action)
{
struct vma_iterator *vmi = map->vmi;
- int error = 0;
struct vm_area_struct *vma;
+ int error;
/*
* Determine the object being mapped and call the appropriate
@@ -2552,6 +2607,14 @@ static int __mmap_new_vma(struct mmap_st
if (!vma)
return -ENOMEM;
+ /*
+ * Lock the VMA early to avoid extra work if fatal signal
+ * is pending.
+ */
+ error = vma_start_write_killable(vma);
+ if (error)
+ goto free_vma;
+
vma_iter_config(vmi, map->addr, map->end);
vma_set_range(vma, map->addr, map->end, map->pgoff);
vma->flags = map->vma_flags;
@@ -2582,8 +2645,6 @@ static int __mmap_new_vma(struct mmap_st
WARN_ON_ONCE(!arch_validate_flags(map->vm_flags));
#endif
- /* Lock the VMA since it is modified after insertion into VMA tree */
- vma_start_write(vma);
vma_iter_store_new(vmi, vma);
map->mm->map_count++;
vma_link_file(vma, action->hide_from_rmap_until_complete);
@@ -2878,6 +2939,7 @@ int do_brk_flags(struct vma_iterator *vm
unsigned long addr, unsigned long len, vma_flags_t vma_flags)
{
struct mm_struct *mm = current->mm;
+ int err;
/*
* Check against address space limits by the changed size
@@ -2910,24 +2972,33 @@ int do_brk_flags(struct vma_iterator *vm
if (vma_merge_new_range(&vmg))
goto out;
- else if (vmg_nomem(&vmg))
+ if (vmg_nomem(&vmg)) {
+ err = -ENOMEM;
goto unacct_fail;
+ }
}
if (vma)
vma_iter_next_range(vmi);
/* create a vma struct for an anonymous mapping */
vma = vm_area_alloc(mm);
- if (!vma)
+ if (!vma) {
+ err = -ENOMEM;
goto unacct_fail;
+ }
vma_set_anonymous(vma);
vma_set_range(vma, addr, addr + len, addr >> PAGE_SHIFT);
vma->flags = vma_flags;
vma->vm_page_prot = vm_get_page_prot(vma_flags_to_legacy(vma_flags));
- vma_start_write(vma);
- if (vma_iter_store_gfp(vmi, vma, GFP_KERNEL))
+ if (vma_start_write_killable(vma)) {
+ err = -EINTR;
+ goto vma_lock_fail;
+ }
+ if (vma_iter_store_gfp(vmi, vma, GFP_KERNEL)) {
+ err = -ENOMEM;
goto mas_store_fail;
+ }
mm->map_count++;
validate_mm(mm);
@@ -2942,10 +3013,11 @@ out:
return 0;
mas_store_fail:
+vma_lock_fail:
vm_area_free(vma);
unacct_fail:
vm_unacct_memory(len >> PAGE_SHIFT);
- return -ENOMEM;
+ return err;
}
/**
@@ -3112,8 +3184,8 @@ int expand_upwards(struct vm_area_struct
struct mm_struct *mm = vma->vm_mm;
struct vm_area_struct *next;
unsigned long gap_addr;
- int error = 0;
VMA_ITERATOR(vmi, mm, vma->vm_start);
+ int error;
if (!vma_test(vma, VMA_GROWSUP_BIT))
return -EFAULT;
@@ -3149,12 +3221,14 @@ int expand_upwards(struct vm_area_struct
/* We must make sure the anon_vma is allocated. */
if (unlikely(anon_vma_prepare(vma))) {
- vma_iter_free(&vmi);
- return -ENOMEM;
+ error = -ENOMEM;
+ goto vma_prep_fail;
}
/* Lock the VMA before expanding to prevent concurrent page faults */
- vma_start_write(vma);
+ error = vma_start_write_killable(vma);
+ if (error)
+ goto vma_lock_fail;
/* We update the anon VMA tree. */
anon_vma_lock_write(vma->anon_vma);
@@ -3183,8 +3257,10 @@ int expand_upwards(struct vm_area_struct
}
}
anon_vma_unlock_write(vma->anon_vma);
- vma_iter_free(&vmi);
validate_mm(mm);
+vma_lock_fail:
+vma_prep_fail:
+ vma_iter_free(&vmi);
return error;
}
#endif /* CONFIG_STACK_GROWSUP */
@@ -3197,8 +3273,8 @@ int expand_downwards(struct vm_area_stru
{
struct mm_struct *mm = vma->vm_mm;
struct vm_area_struct *prev;
- int error = 0;
VMA_ITERATOR(vmi, mm, vma->vm_start);
+ int error;
if (!vma_test(vma, VMA_GROWSDOWN_BIT))
return -EFAULT;
@@ -3228,12 +3304,14 @@ int expand_downwards(struct vm_area_stru
/* We must make sure the anon_vma is allocated. */
if (unlikely(anon_vma_prepare(vma))) {
- vma_iter_free(&vmi);
- return -ENOMEM;
+ error = -ENOMEM;
+ goto vma_prep_fail;
}
/* Lock the VMA before expanding to prevent concurrent page faults */
- vma_start_write(vma);
+ error = vma_start_write_killable(vma);
+ if (error)
+ goto vma_lock_fail;
/* We update the anon VMA tree. */
anon_vma_lock_write(vma->anon_vma);
@@ -3263,8 +3341,10 @@ int expand_downwards(struct vm_area_stru
}
}
anon_vma_unlock_write(vma->anon_vma);
- vma_iter_free(&vmi);
validate_mm(mm);
+vma_lock_fail:
+vma_prep_fail:
+ vma_iter_free(&vmi);
return error;
}
--- a/mm/vma_exec.c~mm-vma-use-vma_start_write_killable-in-vma-operations
+++ a/mm/vma_exec.c
@@ -41,6 +41,7 @@ int relocate_vma_down(struct vm_area_str
struct vm_area_struct *next;
struct mmu_gather tlb;
PAGETABLE_MOVE(pmc, vma, vma, old_start, new_start, length);
+ int err;
BUG_ON(new_start > new_end);
@@ -56,8 +57,9 @@ int relocate_vma_down(struct vm_area_str
* cover the whole range: [new_start, old_end)
*/
vmg.target = vma;
- if (vma_expand(&vmg))
- return -ENOMEM;
+ err = vma_expand(&vmg);
+ if (err)
+ return err;
/*
* move the page tables downwards, on failure we rely on
_
Patches currently in -mm which might be from surenb@google.com are
mm-use-vma_start_write_killable-in-process_vma_walk_lock.patch
kvm-ppc-use-vma_start_write_killable-in-kvmppc_memslot_page_merge.patch
mm-vmscan-prevent-mglru-reclaim-from-pinning-address-space.patch
^ permalink raw reply [flat|nested] 2+ messages in thread
end of thread, other threads:[~2026-03-31 18:29 UTC | newest]
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2026-03-31 18:29 [to-be-updated] mm-vma-use-vma_start_write_killable-in-vma-operations.patch removed from -mm tree Andrew Morton
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2026-03-27 23:04 Andrew Morton
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