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From:   SEO HOYOUNG <hy50.seo@samsung.com>
To:     andreyknvl@gmail.com, osalvador@suse.de, akpm@linux-foundation.org,
        linux-kernel@vger.kernel.org, linux-mm@kvack.org, mhocko@suse.com,
        vbabka@suse.cz, edumazet@google.com, longman@redhat.com,
        surenb@google.com, elver@google.com, glider@google.com,
        dvyukov@google.com
Cc:     SEO HOYOUNG <hy50.seo@samsung.com>
Subject: [PATCH v1] lib/stackdepot: limit nr_entries size
Date:   Mon, 17 Apr 2023 14:16:37 +0900
Message-Id: <20230417051637.103964-1-hy50.seo@samsung.com>
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References: <CGME20230417051556epcas2p25b57d681bfae498b30ff33f0a96033d6@epcas2p2.samsung.com>
Precedence: bulk

While using the MCQ feature of UFS, dump stack was detected very deeply.
If this continues to happen, depot_alloc_stack() will continue to exceed
STACK_ALLOC_SIZE and STACK_ALLOC_MAX_SLABS, eventually resulting 
in the warning "Stack depot reached limit capacity".

So want to limit the size of entries stored in it.
25 is a test value, and we found that in a normal case,
the depth of the stack does not exceed 25.

[ 2479.383395]I[0:launcher-loader: 1719] Stack depot reached limit capacity
[ 2479.383538]I[0:launcher-loader: 1719] WARNING: CPU: 0 PID: 1719 at lib/stackdepot.c:129 __stack_depot_save+0x464/0x46c
[ 2479.385693]I[0:launcher-loader: 1719] pstate: 624000c5 (nZCv daIF +PAN -UAO +TCO -DIT -SSBS BTYPE=--)
[ 2479.385724]I[0:launcher-loader: 1719] pc : __stack_depot_save+0x464/0x46c
[ 2479.385751]I[0:launcher-loader: 1719] lr : __stack_depot_save+0x460/0x46c
[ 2479.385774]I[0:launcher-loader: 1719] sp : ffffffc0080073c0
[ 2479.385793]I[0:launcher-loader: 1719] x29: ffffffc0080073e0 x28: ffffffd00b78a000 x27: 0000000000000000
[ 2479.385839]I[0:launcher-loader: 1719] x26: 000000000004d1dd x25: ffffff891474f000 x24: 00000000ca64d1dd
[ 2479.385882]I[0:launcher-loader: 1719] x23: 0000000000000200 x22: 0000000000000220 x21: 0000000000000040
[ 2479.385925]I[0:launcher-loader: 1719] x20: ffffffc008007440 x19: 0000000000000000 x18: 0000000000000000
[ 2479.385969]I[0:launcher-loader: 1719] x17: 2065726568207475 x16: 000000000000005e x15: 2d2d2d2d2d2d2d20
[ 2479.386013]I[0:launcher-loader: 1719] x14: 5d39313731203a72 x13: 00000000002f6b30 x12: 00000000002f6af8
[ 2479.386057]I[0:launcher-loader: 1719] x11: 00000000ffffffff x10: ffffffb90aacf000 x9 : e8a74a6c16008800
[ 2479.386101]I[0:launcher-loader: 1719] x8 : e8a74a6c16008800 x7 : 00000000002f6b30 x6 : 00000000002f6af8
[ 2479.386145]I[0:launcher-loader: 1719] x5 : ffffffc0080070c8 x4 : ffffffd00b192380 x3 : ffffffd0092b313c
[ 2479.386189]I[0:launcher-loader: 1719] x2 : 0000000000000001 x1 : 0000000000000004 x0 : 0000000000000022
[ 2479.386231]I[0:launcher-loader: 1719] Call trace:
[ 2479.386248]I[0:launcher-loader: 1719]  __stack_depot_save+0x464/0x46c
[ 2479.386273]I[0:launcher-loader: 1719]  kasan_save_stack+0x58/0x70
[ 2479.386303]I[0:launcher-loader: 1719]  save_stack_info+0x34/0x138
[ 2479.386331]I[0:launcher-loader: 1719]  kasan_save_free_info+0x18/0x24
[ 2479.386358]I[0:launcher-loader: 1719]  ____kasan_slab_free+0x16c/0x170
[ 2479.386385]I[0:launcher-loader: 1719]  __kasan_slab_free+0x10/0x20
[ 2479.386410]I[0:launcher-loader: 1719]  kmem_cache_free+0x238/0x53c
[ 2479.386435]I[0:launcher-loader: 1719]  mempool_free_slab+0x1c/0x28
[ 2479.386460]I[0:launcher-loader: 1719]  mempool_free+0x7c/0x1a0
[ 2479.386484]I[0:launcher-loader: 1719]  bvec_free+0x34/0x80
[ 2479.386514]I[0:launcher-loader: 1719]  bio_free+0x60/0x98
[ 2479.386540]I[0:launcher-loader: 1719]  bio_put+0x50/0x21c
[ 2479.386567]I[0:launcher-loader: 1719]  f2fs_write_end_io+0x4ac/0x4d0
[ 2479.386594]I[0:launcher-loader: 1719]  bio_endio+0x2dc/0x300
[ 2479.386622]I[0:launcher-loader: 1719]  __dm_io_complete+0x324/0x37c
[ 2479.386650]I[0:launcher-loader: 1719]  dm_io_dec_pending+0x60/0xa4
[ 2479.386676]I[0:launcher-loader: 1719]  clone_endio+0xf8/0x2f0
[ 2479.386700]I[0:launcher-loader: 1719]  bio_endio+0x2dc/0x300
[ 2479.386727]I[0:launcher-loader: 1719]  blk_update_request+0x258/0x63c
[ 2479.386754]I[0:launcher-loader: 1719]  scsi_end_request+0x50/0x304
[ 2479.386782]I[0:launcher-loader: 1719]  scsi_io_completion+0x88/0x160
[ 2479.386808]I[0:launcher-loader: 1719]  scsi_finish_command+0x17c/0x194
[ 2479.386833]I[0:launcher-loader: 1719]  scsi_complete+0xcc/0x158
[ 2479.386859]I[0:launcher-loader: 1719]  blk_mq_complete_request+0x4c/0x5c
[ 2479.386885]I[0:launcher-loader: 1719]  scsi_done_internal+0xf4/0x1e0
[ 2479.386910]I[0:launcher-loader: 1719]  scsi_done+0x14/0x20
[ 2479.386935]I[0:launcher-loader: 1719]  ufshcd_compl_one_cqe+0x578/0x71c
[ 2479.386963]I[0:launcher-loader: 1719]  ufshcd_mcq_poll_cqe_nolock+0xc8/0x150
[ 2479.386991]I[0:launcher-loader: 1719]  ufshcd_intr+0x868/0xc0c
[ 2479.387017]I[0:launcher-loader: 1719]  __handle_irq_event_percpu+0xd0/0x348
[ 2479.387044]I[0:launcher-loader: 1719]  handle_irq_event_percpu+0x24/0x74
[ 2479.387068]I[0:launcher-loader: 1719]  handle_irq_event+0x74/0xe0
[ 2479.387091]I[0:launcher-loader: 1719]  handle_fasteoi_irq+0x174/0x240
[ 2479.387118]I[0:launcher-loader: 1719]  handle_irq_desc+0x7c/0x2c0
[ 2479.387147]I[0:launcher-loader: 1719]  generic_handle_domain_irq+0x1c/0x28
[ 2479.387174]I[0:launcher-loader: 1719]  gic_handle_irq+0x64/0x158
[ 2479.387204]I[0:launcher-loader: 1719]  call_on_irq_stack+0x2c/0x54
[ 2479.387231]I[0:launcher-loader: 1719]  do_interrupt_handler+0x70/0xa0
[ 2479.387258]I[0:launcher-loader: 1719]  el1_interrupt+0x34/0x68
[ 2479.387283]I[0:launcher-loader: 1719]  el1h_64_irq_handler+0x18/0x24
[ 2479.387308]I[0:launcher-loader: 1719]  el1h_64_irq+0x68/0x6c
[ 2479.387332]I[0:launcher-loader: 1719]  blk_attempt_bio_merge+0x8/0x170
[ 2479.387356]I[0:launcher-loader: 1719]  blk_mq_attempt_bio_merge+0x78/0x98
[ 2479.387383]I[0:launcher-loader: 1719]  blk_mq_submit_bio+0x324/0xa40
[ 2479.387409]I[0:launcher-loader: 1719]  __submit_bio+0x104/0x138
[ 2479.387436]I[0:launcher-loader: 1719]  submit_bio_noacct_nocheck+0x1d0/0x4a0
[ 2479.387462]I[0:launcher-loader: 1719]  submit_bio_noacct+0x618/0x804
[ 2479.387487]I[0:launcher-loader: 1719]  submit_bio+0x164/0x180
[ 2479.387511]I[0:launcher-loader: 1719]  f2fs_submit_read_bio+0xe4/0x1c4
[ 2479.387537]I[0:launcher-loader: 1719]  f2fs_mpage_readpages+0x888/0xa4c
[ 2479.387563]I[0:launcher-loader: 1719]  f2fs_readahead+0xd4/0x19c
[ 2479.387587]I[0:launcher-loader: 1719]  read_pages+0xb0/0x4ac
[ 2479.387614]I[0:launcher-loader: 1719]  page_cache_ra_unbounded+0x238/0x288
[ 2479.387642]I[0:launcher-loader: 1719]  do_page_cache_ra+0x60/0x6c
[ 2479.387669]I[0:launcher-loader: 1719]  page_cache_ra_order+0x318/0x364
[ 2479.387695]I[0:launcher-loader: 1719]  ondemand_readahead+0x30c/0x3d8
[ 2479.387722]I[0:launcher-loader: 1719]  page_cache_sync_ra+0xb4/0xc8
[ 2479.387749]I[0:launcher-loader: 1719]  filemap_read+0x268/0xd24
[ 2479.387777]I[0:launcher-loader: 1719]  f2fs_file_read_iter+0x1a0/0x62c
[ 2479.387806]I[0:launcher-loader: 1719]  vfs_read+0x258/0x34c
[ 2479.387831]I[0:launcher-loader: 1719]  ksys_pread64+0x8c/0xd0
[ 2479.387857]I[0:launcher-loader: 1719]  __arm64_sys_pread64+0x48/0x54
[ 2479.387881]I[0:launcher-loader: 1719]  invoke_syscall+0x58/0x158
[ 2479.387909]I[0:launcher-loader: 1719]  el0_svc_common+0xf0/0x134
[ 2479.387935]I[0:launcher-loader: 1719]  do_el0_svc+0x44/0x114
[ 2479.387961]I[0:launcher-loader: 1719]  el0_svc+0x2c/0x80
[ 2479.387985]I[0:launcher-loader: 1719]  el0t_64_sync_handler+0x48/0x114
[ 2479.388010]I[0:launcher-loader: 1719]  el0t_64_sync+0x190/0x194
[ 2479.388038]I[0:launcher-loader: 1719] Kernel panic - not syncing: kernel: panic_on_warn set ...

Signed-off-by: SEO HOYOUNG <hy50.seo@samsung.com>
---
 lib/stackdepot.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/lib/stackdepot.c b/lib/stackdepot.c
index 2f5aa851834e..f158729598a6 100644
--- a/lib/stackdepot.c
+++ b/lib/stackdepot.c
@@ -43,6 +43,7 @@
 #define DEPOT_MAX_POOLS \
 	(((1LL << (DEPOT_POOL_INDEX_BITS)) < DEPOT_POOLS_CAP) ? \
 	 (1LL << (DEPOT_POOL_INDEX_BITS)) : DEPOT_POOLS_CAP)
+#define DEPO_MAX_DEPTH	25
 
 /* Compact structure that stores a reference to a stack. */
 union handle_parts {
@@ -375,7 +376,7 @@ depot_stack_handle_t __stack_depot_save(unsigned long *entries,
 	 * filter_irq_stacks() to simplify all callers' use of stack depot.
 	 */
 	nr_entries = filter_irq_stacks(entries, nr_entries);
-
+	nr_entries = nr_entries > DEPO_MAX_DEPTH ? DEPO_MAX_DEPTH : nr_entries;
 	if (unlikely(nr_entries == 0) || stack_depot_disabled)
 		goto fast_exit;
 
-- 
2.26.0