The patch titled
Subject: mm/memory_hotplug: add missing mem_hotplug_lock
has been added to the -mm mm-hotfixes-unstable branch. Its filename is
mm-memory_hotplug-add-missing-mem_hotplug_lock.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patche…
This patch will later appear in the mm-hotfixes-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Sumanth Korikkar <sumanthk(a)linux.ibm.com>
Subject: mm/memory_hotplug: add missing mem_hotplug_lock
Date: Mon, 20 Nov 2023 15:53:52 +0100
From Documentation/core-api/memory-hotplug.rst:
When adding/removing/onlining/offlining memory or adding/removing
heterogeneous/device memory, we should always hold the mem_hotplug_lock
in write mode to serialise memory hotplug (e.g. access to global/zone
variables).
mhp_(de)init_memmap_on_memory() functions can change zone stats and
struct page content, but they are currently called w/o the
mem_hotplug_lock.
When memory block is being offlined and when kmemleak goes through each
populated zone, the following theoretical race conditions could occur:
CPU 0: | CPU 1:
memory_offline() |
-> offline_pages() |
-> mem_hotplug_begin() |
... |
-> mem_hotplug_done() |
| kmemleak_scan()
| -> get_online_mems()
| ...
-> mhp_deinit_memmap_on_memory() |
[not protected by mem_hotplug_begin/done()]|
Marks memory section as offline, | Retrieves zone_start_pfn
poisons vmemmap struct pages and updates | and struct page members.
the zone related data |
| ...
| -> put_online_mems()
Fix this by ensuring mem_hotplug_lock is taken before performing
mhp_init_memmap_on_memory(). Also ensure that
mhp_deinit_memmap_on_memory() holds the lock.
online/offline_pages() are currently only called from
memory_block_online/offline(), so it is safe to move the locking there.
Link: https://lkml.kernel.org/r/20231120145354.308999-2-sumanthk@linux.ibm.com
Fixes: a08a2ae34613 ("mm,memory_hotplug: allocate memmap from the added memory range")
Signed-off-by: Sumanth Korikkar <sumanthk(a)linux.ibm.com>
Reviewed-by: Gerald Schaefer <gerald.schaefer(a)linux.ibm.com>
Acked-by: David Hildenbrand <david(a)redhat.com>
Cc: Alexander Gordeev <agordeev(a)linux.ibm.com>
Cc: Aneesh Kumar K.V <aneesh.kumar(a)linux.ibm.com>
Cc: Anshuman Khandual <anshuman.khandual(a)arm.com>
Cc: Heiko Carstens <hca(a)linux.ibm.com>
Cc: Michal Hocko <mhocko(a)suse.com>
Cc: Oscar Salvador <osalvador(a)suse.de>
Cc: Vasily Gorbik <gor(a)linux.ibm.com>
Cc: kernel test robot <lkp(a)intel.com>
Cc: <stable(a)vger.kernel.org> [5.15+]
Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org>
---
drivers/base/memory.c | 18 +++++++++++++++---
mm/memory_hotplug.c | 13 ++++++-------
2 files changed, 21 insertions(+), 10 deletions(-)
--- a/drivers/base/memory.c~mm-memory_hotplug-add-missing-mem_hotplug_lock
+++ a/drivers/base/memory.c
@@ -180,6 +180,9 @@ static inline unsigned long memblk_nr_po
}
#endif
+/*
+ * Must acquire mem_hotplug_lock in write mode.
+ */
static int memory_block_online(struct memory_block *mem)
{
unsigned long start_pfn = section_nr_to_pfn(mem->start_section_nr);
@@ -204,10 +207,11 @@ static int memory_block_online(struct me
if (mem->altmap)
nr_vmemmap_pages = mem->altmap->free;
+ mem_hotplug_begin();
if (nr_vmemmap_pages) {
ret = mhp_init_memmap_on_memory(start_pfn, nr_vmemmap_pages, zone);
if (ret)
- return ret;
+ goto out;
}
ret = online_pages(start_pfn + nr_vmemmap_pages,
@@ -215,7 +219,7 @@ static int memory_block_online(struct me
if (ret) {
if (nr_vmemmap_pages)
mhp_deinit_memmap_on_memory(start_pfn, nr_vmemmap_pages);
- return ret;
+ goto out;
}
/*
@@ -227,9 +231,14 @@ static int memory_block_online(struct me
nr_vmemmap_pages);
mem->zone = zone;
+out:
+ mem_hotplug_done();
return ret;
}
+/*
+ * Must acquire mem_hotplug_lock in write mode.
+ */
static int memory_block_offline(struct memory_block *mem)
{
unsigned long start_pfn = section_nr_to_pfn(mem->start_section_nr);
@@ -247,6 +256,7 @@ static int memory_block_offline(struct m
if (mem->altmap)
nr_vmemmap_pages = mem->altmap->free;
+ mem_hotplug_begin();
if (nr_vmemmap_pages)
adjust_present_page_count(pfn_to_page(start_pfn), mem->group,
-nr_vmemmap_pages);
@@ -258,13 +268,15 @@ static int memory_block_offline(struct m
if (nr_vmemmap_pages)
adjust_present_page_count(pfn_to_page(start_pfn),
mem->group, nr_vmemmap_pages);
- return ret;
+ goto out;
}
if (nr_vmemmap_pages)
mhp_deinit_memmap_on_memory(start_pfn, nr_vmemmap_pages);
mem->zone = NULL;
+out:
+ mem_hotplug_done();
return ret;
}
--- a/mm/memory_hotplug.c~mm-memory_hotplug-add-missing-mem_hotplug_lock
+++ a/mm/memory_hotplug.c
@@ -1129,6 +1129,9 @@ void mhp_deinit_memmap_on_memory(unsigne
kasan_remove_zero_shadow(__va(PFN_PHYS(pfn)), PFN_PHYS(nr_pages));
}
+/*
+ * Must be called with mem_hotplug_lock in write mode.
+ */
int __ref online_pages(unsigned long pfn, unsigned long nr_pages,
struct zone *zone, struct memory_group *group)
{
@@ -1149,7 +1152,6 @@ int __ref online_pages(unsigned long pfn
!IS_ALIGNED(pfn + nr_pages, PAGES_PER_SECTION)))
return -EINVAL;
- mem_hotplug_begin();
/* associate pfn range with the zone */
move_pfn_range_to_zone(zone, pfn, nr_pages, NULL, MIGRATE_ISOLATE);
@@ -1208,7 +1210,6 @@ int __ref online_pages(unsigned long pfn
writeback_set_ratelimit();
memory_notify(MEM_ONLINE, &arg);
- mem_hotplug_done();
return 0;
failed_addition:
@@ -1217,7 +1218,6 @@ failed_addition:
(((unsigned long long) pfn + nr_pages) << PAGE_SHIFT) - 1);
memory_notify(MEM_CANCEL_ONLINE, &arg);
remove_pfn_range_from_zone(zone, pfn, nr_pages);
- mem_hotplug_done();
return ret;
}
@@ -1863,6 +1863,9 @@ static int count_system_ram_pages_cb(uns
return 0;
}
+/*
+ * Must be called with mem_hotplug_lock in write mode.
+ */
int __ref offline_pages(unsigned long start_pfn, unsigned long nr_pages,
struct zone *zone, struct memory_group *group)
{
@@ -1885,8 +1888,6 @@ int __ref offline_pages(unsigned long st
!IS_ALIGNED(start_pfn + nr_pages, PAGES_PER_SECTION)))
return -EINVAL;
- mem_hotplug_begin();
-
/*
* Don't allow to offline memory blocks that contain holes.
* Consequently, memory blocks with holes can never get onlined
@@ -2031,7 +2032,6 @@ int __ref offline_pages(unsigned long st
memory_notify(MEM_OFFLINE, &arg);
remove_pfn_range_from_zone(zone, start_pfn, nr_pages);
- mem_hotplug_done();
return 0;
failed_removal_isolated:
@@ -2046,7 +2046,6 @@ failed_removal:
(unsigned long long) start_pfn << PAGE_SHIFT,
((unsigned long long) end_pfn << PAGE_SHIFT) - 1,
reason);
- mem_hotplug_done();
return ret;
}
_
Patches currently in -mm which might be from sumanthk(a)linux.ibm.com are
mm-memory_hotplug-add-missing-mem_hotplug_lock.patch
mm-memory_hotplug-fix-error-handling-in-add_memory_resource.patch
mm-use-vmem_altmap-code-without-config_zone_device.patch
Like various other ASUS ExpertBook-s, the ASUS ExpertBook B1402CVA
has an ACPI DSDT table that describes IRQ 1 as ActiveLow while
the kernel overrides it to EdgeHigh.
This prevents the keyboard from working. To fix this issue, add this laptop
to the skip_override_table so that the kernel does not override IRQ 1.
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=218114
Cc: stable(a)vger.kernel.org
Signed-off-by: Hans de Goede <hdegoede(a)redhat.com>
---
drivers/acpi/resource.c | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/drivers/acpi/resource.c b/drivers/acpi/resource.c
index 15a3bdbd0755..9bd9f79cd409 100644
--- a/drivers/acpi/resource.c
+++ b/drivers/acpi/resource.c
@@ -447,6 +447,13 @@ static const struct dmi_system_id irq1_level_low_skip_override[] = {
DMI_MATCH(DMI_BOARD_NAME, "B1402CBA"),
},
},
+ {
+ /* Asus ExpertBook B1402CVA */
+ .matches = {
+ DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
+ DMI_MATCH(DMI_BOARD_NAME, "B1402CVA"),
+ },
+ },
{
/* Asus ExpertBook B1502CBA */
.matches = {
--
2.41.0