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 76303ee8d54bff6d9a6d55997acd88a6c2ba63cf
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025071423-imbecile-slander-d8e9@gregkh' --subject-prefix 'PATCH 5.4.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 76303ee8d54bff6d9a6d55997acd88a6c2ba63cf Mon Sep 17 00:00:00 2001
From: Jann Horn <jannh(a)google.com>
Date: Wed, 2 Jul 2025 10:32:04 +0200
Subject: [PATCH] x86/mm: Disable hugetlb page table sharing on 32-bit
Only select ARCH_WANT_HUGE_PMD_SHARE on 64-bit x86.
Page table sharing requires at least three levels because it involves
shared references to PMD tables; 32-bit x86 has either two-level paging
(without PAE) or three-level paging (with PAE), but even with
three-level paging, having a dedicated PGD entry for hugetlb is only
barely possible (because the PGD only has four entries), and it seems
unlikely anyone's actually using PMD sharing on 32-bit.
Having ARCH_WANT_HUGE_PMD_SHARE enabled on non-PAE 32-bit X86 (which
has 2-level paging) became particularly problematic after commit
59d9094df3d7 ("mm: hugetlb: independent PMD page table shared count"),
since that changes `struct ptdesc` such that the `pt_mm` (for PGDs) and
the `pt_share_count` (for PMDs) share the same union storage - and with
2-level paging, PMDs are PGDs.
(For comparison, arm64 also gates ARCH_WANT_HUGE_PMD_SHARE on the
configuration of page tables such that it is never enabled with 2-level
paging.)
Closes: https://lore.kernel.org/r/srhpjxlqfna67blvma5frmy3aa@altlinux.org
Fixes: cfe28c5d63d8 ("x86: mm: Remove x86 version of huge_pmd_share.")
Reported-by: Vitaly Chikunov <vt(a)altlinux.org>
Suggested-by: Dave Hansen <dave.hansen(a)intel.com>
Signed-off-by: Jann Horn <jannh(a)google.com>
Signed-off-by: Dave Hansen <dave.hansen(a)linux.intel.com>
Acked-by: Oscar Salvador <osalvador(a)suse.de>
Acked-by: David Hildenbrand <david(a)redhat.com>
Tested-by: Vitaly Chikunov <vt(a)altlinux.org>
Cc:stable@vger.kernel.org
Link: https://lore.kernel.org/all/20250702-x86-2level-hugetlb-v2-1-1a98096edf92%4…
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 71019b3b54ea..4e0fe688cc83 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -147,7 +147,7 @@ config X86
select ARCH_WANTS_DYNAMIC_TASK_STRUCT
select ARCH_WANTS_NO_INSTR
select ARCH_WANT_GENERAL_HUGETLB
- select ARCH_WANT_HUGE_PMD_SHARE
+ select ARCH_WANT_HUGE_PMD_SHARE if X86_64
select ARCH_WANT_LD_ORPHAN_WARN
select ARCH_WANT_OPTIMIZE_DAX_VMEMMAP if X86_64
select ARCH_WANT_OPTIMIZE_HUGETLB_VMEMMAP if X86_64
The patch below does not apply to the 5.10-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-5.10.y
git checkout FETCH_HEAD
git cherry-pick -x 76303ee8d54bff6d9a6d55997acd88a6c2ba63cf
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025071422-target-professor-6f97@gregkh' --subject-prefix 'PATCH 5.10.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 76303ee8d54bff6d9a6d55997acd88a6c2ba63cf Mon Sep 17 00:00:00 2001
From: Jann Horn <jannh(a)google.com>
Date: Wed, 2 Jul 2025 10:32:04 +0200
Subject: [PATCH] x86/mm: Disable hugetlb page table sharing on 32-bit
Only select ARCH_WANT_HUGE_PMD_SHARE on 64-bit x86.
Page table sharing requires at least three levels because it involves
shared references to PMD tables; 32-bit x86 has either two-level paging
(without PAE) or three-level paging (with PAE), but even with
three-level paging, having a dedicated PGD entry for hugetlb is only
barely possible (because the PGD only has four entries), and it seems
unlikely anyone's actually using PMD sharing on 32-bit.
Having ARCH_WANT_HUGE_PMD_SHARE enabled on non-PAE 32-bit X86 (which
has 2-level paging) became particularly problematic after commit
59d9094df3d7 ("mm: hugetlb: independent PMD page table shared count"),
since that changes `struct ptdesc` such that the `pt_mm` (for PGDs) and
the `pt_share_count` (for PMDs) share the same union storage - and with
2-level paging, PMDs are PGDs.
(For comparison, arm64 also gates ARCH_WANT_HUGE_PMD_SHARE on the
configuration of page tables such that it is never enabled with 2-level
paging.)
Closes: https://lore.kernel.org/r/srhpjxlqfna67blvma5frmy3aa@altlinux.org
Fixes: cfe28c5d63d8 ("x86: mm: Remove x86 version of huge_pmd_share.")
Reported-by: Vitaly Chikunov <vt(a)altlinux.org>
Suggested-by: Dave Hansen <dave.hansen(a)intel.com>
Signed-off-by: Jann Horn <jannh(a)google.com>
Signed-off-by: Dave Hansen <dave.hansen(a)linux.intel.com>
Acked-by: Oscar Salvador <osalvador(a)suse.de>
Acked-by: David Hildenbrand <david(a)redhat.com>
Tested-by: Vitaly Chikunov <vt(a)altlinux.org>
Cc:stable@vger.kernel.org
Link: https://lore.kernel.org/all/20250702-x86-2level-hugetlb-v2-1-1a98096edf92%4…
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 71019b3b54ea..4e0fe688cc83 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -147,7 +147,7 @@ config X86
select ARCH_WANTS_DYNAMIC_TASK_STRUCT
select ARCH_WANTS_NO_INSTR
select ARCH_WANT_GENERAL_HUGETLB
- select ARCH_WANT_HUGE_PMD_SHARE
+ select ARCH_WANT_HUGE_PMD_SHARE if X86_64
select ARCH_WANT_LD_ORPHAN_WARN
select ARCH_WANT_OPTIMIZE_DAX_VMEMMAP if X86_64
select ARCH_WANT_OPTIMIZE_HUGETLB_VMEMMAP if X86_64
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 76303ee8d54bff6d9a6d55997acd88a6c2ba63cf
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025071421-molar-theme-43d7@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 76303ee8d54bff6d9a6d55997acd88a6c2ba63cf Mon Sep 17 00:00:00 2001
From: Jann Horn <jannh(a)google.com>
Date: Wed, 2 Jul 2025 10:32:04 +0200
Subject: [PATCH] x86/mm: Disable hugetlb page table sharing on 32-bit
Only select ARCH_WANT_HUGE_PMD_SHARE on 64-bit x86.
Page table sharing requires at least three levels because it involves
shared references to PMD tables; 32-bit x86 has either two-level paging
(without PAE) or three-level paging (with PAE), but even with
three-level paging, having a dedicated PGD entry for hugetlb is only
barely possible (because the PGD only has four entries), and it seems
unlikely anyone's actually using PMD sharing on 32-bit.
Having ARCH_WANT_HUGE_PMD_SHARE enabled on non-PAE 32-bit X86 (which
has 2-level paging) became particularly problematic after commit
59d9094df3d7 ("mm: hugetlb: independent PMD page table shared count"),
since that changes `struct ptdesc` such that the `pt_mm` (for PGDs) and
the `pt_share_count` (for PMDs) share the same union storage - and with
2-level paging, PMDs are PGDs.
(For comparison, arm64 also gates ARCH_WANT_HUGE_PMD_SHARE on the
configuration of page tables such that it is never enabled with 2-level
paging.)
Closes: https://lore.kernel.org/r/srhpjxlqfna67blvma5frmy3aa@altlinux.org
Fixes: cfe28c5d63d8 ("x86: mm: Remove x86 version of huge_pmd_share.")
Reported-by: Vitaly Chikunov <vt(a)altlinux.org>
Suggested-by: Dave Hansen <dave.hansen(a)intel.com>
Signed-off-by: Jann Horn <jannh(a)google.com>
Signed-off-by: Dave Hansen <dave.hansen(a)linux.intel.com>
Acked-by: Oscar Salvador <osalvador(a)suse.de>
Acked-by: David Hildenbrand <david(a)redhat.com>
Tested-by: Vitaly Chikunov <vt(a)altlinux.org>
Cc:stable@vger.kernel.org
Link: https://lore.kernel.org/all/20250702-x86-2level-hugetlb-v2-1-1a98096edf92%4…
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 71019b3b54ea..4e0fe688cc83 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -147,7 +147,7 @@ config X86
select ARCH_WANTS_DYNAMIC_TASK_STRUCT
select ARCH_WANTS_NO_INSTR
select ARCH_WANT_GENERAL_HUGETLB
- select ARCH_WANT_HUGE_PMD_SHARE
+ select ARCH_WANT_HUGE_PMD_SHARE if X86_64
select ARCH_WANT_LD_ORPHAN_WARN
select ARCH_WANT_OPTIMIZE_DAX_VMEMMAP if X86_64
select ARCH_WANT_OPTIMIZE_HUGETLB_VMEMMAP if X86_64
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 76303ee8d54bff6d9a6d55997acd88a6c2ba63cf
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025071420-occupy-vowel-a8a5@gregkh' --subject-prefix 'PATCH 6.1.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 76303ee8d54bff6d9a6d55997acd88a6c2ba63cf Mon Sep 17 00:00:00 2001
From: Jann Horn <jannh(a)google.com>
Date: Wed, 2 Jul 2025 10:32:04 +0200
Subject: [PATCH] x86/mm: Disable hugetlb page table sharing on 32-bit
Only select ARCH_WANT_HUGE_PMD_SHARE on 64-bit x86.
Page table sharing requires at least three levels because it involves
shared references to PMD tables; 32-bit x86 has either two-level paging
(without PAE) or three-level paging (with PAE), but even with
three-level paging, having a dedicated PGD entry for hugetlb is only
barely possible (because the PGD only has four entries), and it seems
unlikely anyone's actually using PMD sharing on 32-bit.
Having ARCH_WANT_HUGE_PMD_SHARE enabled on non-PAE 32-bit X86 (which
has 2-level paging) became particularly problematic after commit
59d9094df3d7 ("mm: hugetlb: independent PMD page table shared count"),
since that changes `struct ptdesc` such that the `pt_mm` (for PGDs) and
the `pt_share_count` (for PMDs) share the same union storage - and with
2-level paging, PMDs are PGDs.
(For comparison, arm64 also gates ARCH_WANT_HUGE_PMD_SHARE on the
configuration of page tables such that it is never enabled with 2-level
paging.)
Closes: https://lore.kernel.org/r/srhpjxlqfna67blvma5frmy3aa@altlinux.org
Fixes: cfe28c5d63d8 ("x86: mm: Remove x86 version of huge_pmd_share.")
Reported-by: Vitaly Chikunov <vt(a)altlinux.org>
Suggested-by: Dave Hansen <dave.hansen(a)intel.com>
Signed-off-by: Jann Horn <jannh(a)google.com>
Signed-off-by: Dave Hansen <dave.hansen(a)linux.intel.com>
Acked-by: Oscar Salvador <osalvador(a)suse.de>
Acked-by: David Hildenbrand <david(a)redhat.com>
Tested-by: Vitaly Chikunov <vt(a)altlinux.org>
Cc:stable@vger.kernel.org
Link: https://lore.kernel.org/all/20250702-x86-2level-hugetlb-v2-1-1a98096edf92%4…
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 71019b3b54ea..4e0fe688cc83 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -147,7 +147,7 @@ config X86
select ARCH_WANTS_DYNAMIC_TASK_STRUCT
select ARCH_WANTS_NO_INSTR
select ARCH_WANT_GENERAL_HUGETLB
- select ARCH_WANT_HUGE_PMD_SHARE
+ select ARCH_WANT_HUGE_PMD_SHARE if X86_64
select ARCH_WANT_LD_ORPHAN_WARN
select ARCH_WANT_OPTIMIZE_DAX_VMEMMAP if X86_64
select ARCH_WANT_OPTIMIZE_HUGETLB_VMEMMAP if X86_64
After commit 725f31f300e3 ("thermal/of: support thermal zones w/o trips
subnode") was backported on 6.6 stable branch as commit d3304dbc2d5f
("thermal/of: support thermal zones w/o trips subnode"), thermal zones
w/o trips subnode still fail to register since `mask` argument is not
set correctly. When number of trips subnode is 0, `mask` must be 0 to
pass the check in `thermal_zone_device_register_with_trips()`.
Set `mask` to 0 when there's no trips subnode.
Signed-off-by: Hsin-Te Yuan <yuanhsinte(a)chromium.org>
---
drivers/thermal/thermal_of.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/thermal/thermal_of.c b/drivers/thermal/thermal_of.c
index 0f520cf923a1e684411a3077ad283551395eec11..97aeb869abf5179dfa512dd744725121ec7fd0d9 100644
--- a/drivers/thermal/thermal_of.c
+++ b/drivers/thermal/thermal_of.c
@@ -514,7 +514,7 @@ static struct thermal_zone_device *thermal_of_zone_register(struct device_node *
of_ops->bind = thermal_of_bind;
of_ops->unbind = thermal_of_unbind;
- mask = GENMASK_ULL((ntrips) - 1, 0);
+ mask = ntrips ? GENMASK_ULL((ntrips) - 1, 0) : 0;
tz = thermal_zone_device_register_with_trips(np->name, trips, ntrips,
mask, data, of_ops, &tzp,
---
base-commit: a5df3a702b2cba82bcfb066fa9f5e4a349c33924
change-id: 20250707-trip-point-73dae9fd9c74
Best regards,
--
Hsin-Te Yuan <yuanhsinte(a)chromium.org>
The grp->bb_largest_free_order is updated regardless of whether
mb_optimize_scan is enabled. This can lead to inconsistencies between
grp->bb_largest_free_order and the actual s_mb_largest_free_orders list
index when mb_optimize_scan is repeatedly enabled and disabled via remount.
For example, if mb_optimize_scan is initially enabled, largest free
order is 3, and the group is in s_mb_largest_free_orders[3]. Then,
mb_optimize_scan is disabled via remount, block allocations occur,
updating largest free order to 2. Finally, mb_optimize_scan is re-enabled
via remount, more block allocations update largest free order to 1.
At this point, the group would be removed from s_mb_largest_free_orders[3]
under the protection of s_mb_largest_free_orders_locks[2]. This lock
mismatch can lead to list corruption.
To fix this, whenever grp->bb_largest_free_order changes, we now always
attempt to remove the group from its old order list. However, we only
insert the group into the new order list if `mb_optimize_scan` is enabled.
This approach helps prevent lock inconsistencies and ensures the data in
the order lists remains reliable.
Fixes: 196e402adf2e ("ext4: improve cr 0 / cr 1 group scanning")
CC: stable(a)vger.kernel.org
Suggested-by: Jan Kara <jack(a)suse.cz>
Signed-off-by: Baokun Li <libaokun1(a)huawei.com>
---
fs/ext4/mballoc.c | 33 ++++++++++++++-------------------
1 file changed, 14 insertions(+), 19 deletions(-)
diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
index 72b20fc52bbf..fada0d1b3fdb 100644
--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c
@@ -1152,33 +1152,28 @@ static void
mb_set_largest_free_order(struct super_block *sb, struct ext4_group_info *grp)
{
struct ext4_sb_info *sbi = EXT4_SB(sb);
- int i;
+ int new, old = grp->bb_largest_free_order;
- for (i = MB_NUM_ORDERS(sb) - 1; i >= 0; i--)
- if (grp->bb_counters[i] > 0)
+ for (new = MB_NUM_ORDERS(sb) - 1; new >= 0; new--)
+ if (grp->bb_counters[new] > 0)
break;
+
/* No need to move between order lists? */
- if (!test_opt2(sb, MB_OPTIMIZE_SCAN) ||
- i == grp->bb_largest_free_order) {
- grp->bb_largest_free_order = i;
+ if (new == old)
return;
- }
- if (grp->bb_largest_free_order >= 0) {
- write_lock(&sbi->s_mb_largest_free_orders_locks[
- grp->bb_largest_free_order]);
+ if (old >= 0 && !list_empty(&grp->bb_largest_free_order_node)) {
+ write_lock(&sbi->s_mb_largest_free_orders_locks[old]);
list_del_init(&grp->bb_largest_free_order_node);
- write_unlock(&sbi->s_mb_largest_free_orders_locks[
- grp->bb_largest_free_order]);
+ write_unlock(&sbi->s_mb_largest_free_orders_locks[old]);
}
- grp->bb_largest_free_order = i;
- if (grp->bb_largest_free_order >= 0 && grp->bb_free) {
- write_lock(&sbi->s_mb_largest_free_orders_locks[
- grp->bb_largest_free_order]);
+
+ grp->bb_largest_free_order = new;
+ if (test_opt2(sb, MB_OPTIMIZE_SCAN) && new >= 0 && grp->bb_free) {
+ write_lock(&sbi->s_mb_largest_free_orders_locks[new]);
list_add_tail(&grp->bb_largest_free_order_node,
- &sbi->s_mb_largest_free_orders[grp->bb_largest_free_order]);
- write_unlock(&sbi->s_mb_largest_free_orders_locks[
- grp->bb_largest_free_order]);
+ &sbi->s_mb_largest_free_orders[new]);
+ write_unlock(&sbi->s_mb_largest_free_orders_locks[new]);
}
}
--
2.46.1
Groups with no free blocks shouldn't be in any average fragment size list.
However, when all blocks in a group are allocated(i.e., bb_fragments or
bb_free is 0), we currently skip updating the average fragment size, which
means the group isn't removed from its previous s_mb_avg_fragment_size[old]
list.
This created "zombie" groups that were always skipped during traversal as
they couldn't satisfy any block allocation requests, negatively impacting
traversal efficiency.
Therefore, when a group becomes completely full, bb_avg_fragment_size_order
is now set to -1. If the old order was not -1, a removal operation is
performed; if the new order is not -1, an insertion is performed.
Fixes: 196e402adf2e ("ext4: improve cr 0 / cr 1 group scanning")
CC: stable(a)vger.kernel.org
Signed-off-by: Baokun Li <libaokun1(a)huawei.com>
Reviewed-by: Jan Kara <jack(a)suse.cz>
---
fs/ext4/mballoc.c | 36 ++++++++++++++++++------------------
1 file changed, 18 insertions(+), 18 deletions(-)
diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
index 6d98f2a5afc4..72b20fc52bbf 100644
--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c
@@ -841,30 +841,30 @@ static void
mb_update_avg_fragment_size(struct super_block *sb, struct ext4_group_info *grp)
{
struct ext4_sb_info *sbi = EXT4_SB(sb);
- int new_order;
+ int new, old;
- if (!test_opt2(sb, MB_OPTIMIZE_SCAN) || grp->bb_fragments == 0)
+ if (!test_opt2(sb, MB_OPTIMIZE_SCAN))
return;
- new_order = mb_avg_fragment_size_order(sb,
- grp->bb_free / grp->bb_fragments);
- if (new_order == grp->bb_avg_fragment_size_order)
+ old = grp->bb_avg_fragment_size_order;
+ new = grp->bb_fragments == 0 ? -1 :
+ mb_avg_fragment_size_order(sb, grp->bb_free / grp->bb_fragments);
+ if (new == old)
return;
- if (grp->bb_avg_fragment_size_order != -1) {
- write_lock(&sbi->s_mb_avg_fragment_size_locks[
- grp->bb_avg_fragment_size_order]);
+ if (old >= 0) {
+ write_lock(&sbi->s_mb_avg_fragment_size_locks[old]);
list_del(&grp->bb_avg_fragment_size_node);
- write_unlock(&sbi->s_mb_avg_fragment_size_locks[
- grp->bb_avg_fragment_size_order]);
- }
- grp->bb_avg_fragment_size_order = new_order;
- write_lock(&sbi->s_mb_avg_fragment_size_locks[
- grp->bb_avg_fragment_size_order]);
- list_add_tail(&grp->bb_avg_fragment_size_node,
- &sbi->s_mb_avg_fragment_size[grp->bb_avg_fragment_size_order]);
- write_unlock(&sbi->s_mb_avg_fragment_size_locks[
- grp->bb_avg_fragment_size_order]);
+ write_unlock(&sbi->s_mb_avg_fragment_size_locks[old]);
+ }
+
+ grp->bb_avg_fragment_size_order = new;
+ if (new >= 0) {
+ write_lock(&sbi->s_mb_avg_fragment_size_locks[new]);
+ list_add_tail(&grp->bb_avg_fragment_size_node,
+ &sbi->s_mb_avg_fragment_size[new]);
+ write_unlock(&sbi->s_mb_avg_fragment_size_locks[new]);
+ }
}
/*
--
2.46.1