The patch titled
Subject: lib/stackdepot: double DEPOT_POOLS_CAP if KASAN is enabled
has been added to the -mm mm-hotfixes-unstable branch. Its filename is
lib-stackdepot-double-depot_pools_cap-if-kasan-is-enabled.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/lib-stackdepot-double-depot_pools_cap-if-kasan-is-enabled.patch
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: Waiman Long <longman@xxxxxxxxxx>
Subject: lib/stackdepot: double DEPOT_POOLS_CAP if KASAN is enabled
Date: Wed, 7 Aug 2024 12:52:28 -0400
When a wide variety of workloads are run on a debug kernel with KASAN
enabled, the following warning may sometimes be printed.
[ 6818.650674] Stack depot reached limit capacity
[ 6818.650730] WARNING: CPU: 1 PID: 272741 at lib/stackdepot.c:252 depot_alloc_stack+0x39e/0x3d0
:
[ 6818.650907] Call Trace:
[ 6818.650909] [<00047dd453d84b92>] depot_alloc_stack+0x3a2/0x3d0
[ 6818.650916] [<00047dd453d85254>] stack_depot_save_flags+0x4f4/0x5c0
[ 6818.650920] [<00047dd4535872c6>] kasan_save_stack+0x56/0x70
[ 6818.650924] [<00047dd453587328>] kasan_save_track+0x28/0x40
[ 6818.650927] [<00047dd45358a27a>] kasan_save_free_info+0x4a/0x70
[ 6818.650930] [<00047dd45358766a>] __kasan_slab_free+0x12a/0x1d0
[ 6818.650933] [<00047dd45350deb4>] kmem_cache_free+0x1b4/0x580
[ 6818.650938] [<00047dd452c520da>] __put_task_struct+0x24a/0x320
[ 6818.650945] [<00047dd452c6aee4>] delayed_put_task_struct+0x294/0x350
[ 6818.650949] [<00047dd452e9066a>] rcu_do_batch+0x6ea/0x2090
[ 6818.650953] [<00047dd452ea60f4>] rcu_core+0x474/0xa90
[ 6818.650956] [<00047dd452c780c0>] handle_softirqs+0x3c0/0xf90
[ 6818.650960] [<00047dd452c76fbe>] __irq_exit_rcu+0x35e/0x460
[ 6818.650963] [<00047dd452c79992>] irq_exit_rcu+0x22/0xb0
[ 6818.650966] [<00047dd454bd8128>] do_ext_irq+0xd8/0x120
[ 6818.650972] [<00047dd454c0ddd0>] ext_int_handler+0xb8/0xe8
[ 6818.650979] [<00047dd453589cf6>] kasan_check_range+0x236/0x2f0
[ 6818.650982] [<00047dd453378cf0>] filemap_get_pages+0x190/0xaa0
[ 6818.650986] [<00047dd453379940>] filemap_read+0x340/0xa70
[ 6818.650989] [<00047dd3d325d226>] xfs_file_buffered_read+0x2c6/0x400 [xfs]
[ 6818.651431] [<00047dd3d325dfe2>] xfs_file_read_iter+0x2c2/0x550 [xfs]
[ 6818.651663] [<00047dd45364710c>] vfs_read+0x64c/0x8c0
[ 6818.651669] [<00047dd453648ed8>] ksys_read+0x118/0x200
[ 6818.651672] [<00047dd452b6cf5a>] do_syscall+0x27a/0x380
[ 6818.651676] [<00047dd454bd7e74>] __do_syscall+0xf4/0x1a0
[ 6818.651680] [<00047dd454c0db58>] system_call+0x70/0x98
As KASAN is a big user of stackdepot, the current DEPOT_POOLS_CAP of
8192 may not be enough. Double DEPOT_POOLS_CAP if KASAN is enabled to
avoid hitting this problem.
Also use the MIN() macro for defining DEPOT_MAX_POOLS to clarify the
intention.
Link: https://lkml.kernel.org/r/20240807165228.1116831-1-longman@xxxxxxxxxx
Fixes: 02754e0a484a ("lib/stackdepot.c: bump stackdepot capacity from 16MB to 128MB")
Signed-off-by: Waiman Long <longman@xxxxxxxxxx>
Cc: Andrey Konovalov <andreyknvl@xxxxxxxxxx>
Cc: Andrey Ryabinin <ryabinin.a.a@xxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
lib/stackdepot.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)
--- a/lib/stackdepot.c~lib-stackdepot-double-depot_pools_cap-if-kasan-is-enabled
+++ a/lib/stackdepot.c
@@ -36,11 +36,12 @@
#include <linux/memblock.h>
#include <linux/kasan-enabled.h>
-#define DEPOT_POOLS_CAP 8192
+/* KASAN is a big user of stackdepot, double the cap if KASAN is enabled */
+#define DEPOT_POOLS_CAP (8192 * (IS_ENABLED(CONFIG_KASAN) ? 2 : 1))
+
/* The pool_index is offset by 1 so the first record does not have a 0 handle. */
#define DEPOT_MAX_POOLS \
- (((1LL << (DEPOT_POOL_INDEX_BITS)) - 1 < DEPOT_POOLS_CAP) ? \
- (1LL << (DEPOT_POOL_INDEX_BITS)) - 1 : DEPOT_POOLS_CAP)
+ MIN((1LL << (DEPOT_POOL_INDEX_BITS)) - 1, DEPOT_POOLS_CAP)
static bool stack_depot_disabled;
static bool __stack_depot_early_init_requested __initdata = IS_ENABLED(CONFIG_STACKDEPOT_ALWAYS_INIT);
_
Patches currently in -mm which might be from longman@xxxxxxxxxx are
padata-fix-possible-divide-by-0-panic-in-padata_mt_helper.patch
mm-memory-failure-use-raw_spinlock_t-in-struct-memory_failure_cpu.patch
mm-memory-failure-use-raw_spinlock_t-in-struct-memory_failure_cpu-v3.patch
lib-stackdepot-double-depot_pools_cap-if-kasan-is-enabled.patch
watchdog-handle-the-enodev-failure-case-of-lockup_detector_delay_init-separately.patch
