The patch titled
Subject: mm-fix-null-ptr-deref-in-kswapd_is_running-fix
has been added to the -mm mm-unstable branch. Its filename is
mm-fix-null-ptr-deref-in-kswapd_is_running-fix.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-fix-null-ptr-deref-in-kswapd_is_running-fix.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Subject: mm-fix-null-ptr-deref-in-kswapd_is_running-fix
Date: Sat Aug 27 03:04:21 PM PDT 2022
add comments
Cc: David Hildenbrand <david@xxxxxxxxxx>
Cc: Kefeng Wang <wangkefeng.wang@xxxxxxxxxx>
Cc: Muchun Song <muchun.song@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/memory_hotplug.h | 1 +
mm/compaction.c | 6 ++++++
2 files changed, 7 insertions(+)
--- a/include/linux/memory_hotplug.h~mm-fix-null-ptr-deref-in-kswapd_is_running-fix
+++ a/include/linux/memory_hotplug.h
@@ -215,6 +215,7 @@ void put_online_mems(void);
void mem_hotplug_begin(void);
void mem_hotplug_done(void);
+/* See kswapd_is_running() */
static inline void pgdat_kswapd_lock(pg_data_t *pgdat)
{
mutex_lock(&pgdat->kswapd_lock);
--- a/mm/compaction.c~mm-fix-null-ptr-deref-in-kswapd_is_running-fix
+++ a/mm/compaction.c
@@ -1980,6 +1980,12 @@ static inline bool is_via_compact_memory
return order == -1;
}
+/*
+ * Determine whether kswapd is (or recently was!) running on this node.
+ *
+ * pgdat_kswapd_lock() pins pgdat->kswapd, so a concurrent kswapd_stop() can't
+ * zero it.
+ */
static bool kswapd_is_running(pg_data_t *pgdat)
{
bool running;
_
Patches currently in -mm which might be from akpm@xxxxxxxxxxxxxxxxxxxx are
asm-generic-sections-refactor-memory_intersects-fix.patch
mm-page_alloc-fix-race-condition-between-build_all_zonelists-and-page-allocation-fix.patch
procfs-add-path-to-proc-pid-fdinfo-fix.patch
zsmalloc-zs_object_copy-add-clarifying-comment-fix.patch
mm-gupc-simplify-and-fix-check_and_migrate_movable_pages-return-codes-fix-fix.patch
mm-oom_kill-add-trace-logs-in-process_mrelease-system-call-fix.patch
zsmalloc-zs_object_copy-replace-email-link-to-doc-checkpatch-fixes.patch
mm-demotion-add-support-for-explicit-memory-tiers-fix.patch
mm-demotion-update-node_is_toptier-to-work-with-memory-tiers-fix-2.patch
mm-drop-oom-code-from-exit_mmap-fix-fix.patch
mm-delete-unused-mmf_oom_victim-flag-vs-mglru.patch
mm-add-merging-after-mremap-resize-checkpatch-fixes.patch
mm-gupc-refactor-check_and_migrate_movable_pages-fix.patch
mm-reduce-noise-in-show_mem-for-lowmem-allocations-vs-mapletree.patch
page_ext-introduce-boot-parameter-early_page_ext-fix.patch
mm-fix-null-ptr-deref-in-kswapd_is_running-fix.patch
ia64-fix-clock_getresclock_monotonic-to-report-itc-frequency-checkpatch-fixes.patch
