On Mon, 17 Apr 2023 at 07:16, SEO HOYOUNG <hy50.seo@xxxxxxxxxxx> wrote: > > 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@xxxxxxxxxxx> > --- > 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; Hi SEO, The stack overflow errors are related to total number of stacks rather than size of a single stack. filter_irq_stacks() is somehow not working in your case. It's supposed to strip stacks somewhere around el1_interrupt (on interrupt entry), but it's failing to do it. As a result you are getting an effectively infinite amount of random stacks saved. You need to debug why filter_irq_stacks() is failing in your case and fix that instead.