On Mon, Jun 29, 2020 at 09:39:45PM +0200, Christoph Hellwig wrote: > Split out a __submit_bio_noacct helper for the actual de-recursion > algorithm, and simplify the loop by using a continue when we can't > enter the queue for a bio. > > Signed-off-by: Christoph Hellwig <hch@xxxxxx> Reverting this commit and its dependencies, 5a6c35f9af41 block: remove direct_make_request ff93ea0ce763 block: shortcut __submit_bio_noacct for blk-mq drivers fixed the stack-out-of-bounds during boot, https://lore.kernel.org/linux-block/000000000000bcdeaa05a97280e4@xxxxxxxxxx/ [ 55.573431][ T1373] BUG: KASAN: stack-out-of-bounds in bio_alloc_bioset+0x493/0x4a0 bio_alloc_bioset+0x493/0x4a0: bio_list_empty at include/linux/bio.h:561 (inlined by) bio_alloc_bioset at block/bio.c:482 [ 55.581140][ T1373] Read of size 8 at addr ffffc9000a7df1e0 by task mount/1373 [ 55.588409][ T1373] [ 55.590615][ T1373] CPU: 2 PID: 1373 Comm: mount Not tainted 5.8.0-rc3-next-20200702 #2 [ 55.598672][ T1373] Hardware name: HPE ProLiant DL385 Gen10/ProLiant DL385 Gen10, BIOS A40 07/10/2019 [ 55.607972][ T1373] Call Trace: [ 55.607980][ T1373] dump_stack+0x9d/0xe0 [ 55.607984][ T1373] ? bio_alloc_bioset+0x493/0x4a0 [ 55.607992][ T1373] ? bio_alloc_bioset+0x493/0x4a0 [ 55.625007][ T1373] print_address_description.constprop.8.cold.10+0x56/0x44e [ 55.632191][ T1373] ? bio_alloc_bioset+0x493/0x4a0 [ 55.637100][ T1373] ? bio_alloc_bioset+0x493/0x4a0 [ 55.642011][ T1373] kasan_report.cold.11+0x37/0x7c [ 55.646923][ T1373] ? bio_alloc_bioset+0x493/0x4a0 [ 55.651968][ T1373] bio_alloc_bioset+0x493/0x4a0 [ 55.651971][ T1373] ? bvec_alloc+0x290/0x290 [ 55.651975][ T1373] ? mark_lock+0x147/0x1800 [ 55.651978][ T1373] ? mark_lock+0x147/0x1800 [ 55.651981][ T1373] bio_clone_fast+0xe/0x30 [ 55.651983][ T1373] bio_split+0x8a/0x4c0 [ 55.651986][ T1373] ? print_irqtrace_events+0x270/0x270 [ 55.651990][ T1373] __blk_queue_split+0xc42/0x13e0 [ 55.651998][ T1373] ? __lock_acquire+0xc57/0x4da0 Startin[ 55.693322][ T1373] ? __blk_rq_map_sg+0x14c0/0x14c0 [ 55.699711][ T1373] ? lockdep_hardirqs_on_prepare+0x550/0x550 [ 55.705602][ T1373] ? mark_held_locks+0xb0/0x110 [ 55.705605][ T1373] ? lockdep_hardirqs_on_prepare+0x550/0x550 [ 55.705608][ T1373] ? lockdep_hardirqs_on_prepare+0x550/0x550 [ 55.705611][ T1373] ? find_held_lock+0x33/0x1c0 [ 55.705614][ T1373] ? find_held_lock+0x33/0x1c0 [ 55.705618][ T1373] blk_mq_submit_bio+0x19e/0x1e20 [ 55.705621][ T1373] ? lock_downgrade+0x720/0x720 [ 55.705624][ T1373] ? blk_mq_try_issue_directly+0x140/0x140 [ 55.705628][ T1373] ? rcu_read_lock_sched_held+0xaa/0xd0 [ 55.705631][ T1373] ? rcu_read_lock_bh_held+0xc0/0xc0 [ 55.705635][ T1373] ? blk_queue_enter+0x83c/0x9a0 [ 55.705647][ T1373] ? submit_bio_checks+0x1cc0/0x1cc0 [ 55.767384][ T1373] submit_bio_noacct+0x9c0/0xeb0 [ 55.772212][ T1373] ? blk_queue_enter+0x9a0/0x9a0 [ 55.777038][ T1373] ? lockdep_hardirqs_on_prepare+0x550/0x550 [ 55.782913][ T1373] ? trace_hardirqs_on+0x20/0x1b5 [ 55.787825][ T1373] ? submit_bio+0xe7/0x480 [ 55.792125][ T1373] submit_bio+0xe7/0x480 [ 55.796252][ T1373] ? bio_associate_blkg_from_css+0x4a3/0xd30 [ 55.802124][ T1373] ? submit_bio_noacct+0xeb0/0xeb0 [ 55.807124][ T1373] ? lock_downgrade+0x720/0x720 [ 55.811862][ T1373] ? rcu_read_unlock+0x50/0x50 [ 55.816512][ T1373] ? lockdep_init_map_waits+0x267/0x7b0 [ 55.821948][ T1373] ? lockdep_init_map_waits+0x267/0x7b0 g LVM event acti[ 55.827386][ T1373] ? __raw_spin_lock_init+0x34/0x100 [ 55.833957][ T1373] submit_bio_wait+0xf9/0x200 vation on device[ 55.838521][ T1373] ? submit_bio_wait_endio+0x30/0x30 [ 55.845091][ T1373] xfs_rw_bdev+0x3ca/0x4d0 [ 55.849396][ T1373] xlog_do_io+0x149/0x320 [ 55.853611][ T1373] xlog_bread+0x1e/0xb0 [ 55.857651][ T1373] xlog_find_verify_log_record+0xba/0x4c0 [ 55.863264][ T1373] ? xlog_header_check_mount+0xb0/0xb0 [ 55.868615][ T1373] xlog_find_zeroed+0x2bc/0x4c0 8:3... [ 55.873356][ T1373] ? print_irqtrace_events+0x270/0x270 [ 55.880093][ T1373] ? xlog_find_verify_log_record+0x4c0/0x4c0 [ 55.885966][ T1373] ? __lock_acquire+0x1920/0x4da0 [ 55.890881][ T1373] xlog_find_head+0xd4/0x790 [ 55.895355][ T1373] ? xlog_find_zeroed+0x4c0/0x4c0 [ 55.900269][ T1373] ? rcu_read_lock_sched_held+0xaa/0xd0 [ 55.905708][ T1373] ? rcu_read_lock_bh_held+0xc0/0xc0 [ 55.910885][ T1373] ? sugov_update_single+0x18d/0x4f0 [ 55.916058][ T1373] xlog_find_tail+0xc2/0x810 [ 55.920534][ T1373] ? mark_lock+0x147/0x1800 [ 55.924921][ T1373] ? xlog_verify_head+0x4c0/0x4c0 [ 55.929834][ T1373] ? debug_show_held_locks+0x30/0x50 [ 55.935007][ T1373] ? print_irqtrace_events+0x270/0x270 [ 55.940358][ T1373] ? try_to_wake_up+0x6d1/0xf40 [ 55.945094][ T1373] ? mark_held_locks+0xb0/0x110 [ 55.949835][ T1373] ? lockdep_hardirqs_on_prepare+0x38c/0x550 [ 55.955708][ T1373] ? _raw_spin_unlock_irqrestore+0x39/0x40 [ 55.961410][ T1373] ? trace_hardirqs_on+0x20/0x1b5 [ 55.966324][ T1373] xlog_recover+0x7c/0x480 [ 55.970627][ T1373] ? xlog_buf_readahead+0x110/0x110 [ 55.975715][ T1373] ? migrate_swap_stop+0xbf0/0xbf0 [ 55.980718][ T1373] ? lockdep_init_map_waits+0x267/0x7b0 [ 55.986156][ T1373] ? __raw_spin_lock_init+0x34/0x100 [ 55.991333][ T1373] xfs_log_mount+0x541/0x660 [ 55.995809][ T1373] xfs_mountfs+0xccd/0x1a00 [ 56.000202][ T1373] ? queue_work_node+0x190/0x190 [ 56.005028][ T1373] ? rcu_read_lock_sched_held+0xaa/0xd0 [ 56.010466][ T1373] ? xfs_default_resblks+0x50/0x50 [ 56.015464][ T1373] ? xfs_filestream_get_parent+0xa0/0xa0 [ 56.020989][ T1373] ? init_timer_key+0x285/0x320 [ 56.025727][ T1373] ? lockdep_init_map_waits+0x267/0x7b0 [ 56.031165][ T1373] ? xfs_filestream_get_parent+0xa0/0xa0 [ 56.036689][ T1373] ? xfs_mru_cache_create+0x358/0x560 [ 56.041951][ T1373] xfs_fc_fill_super+0x6d3/0xd50 [ 56.046777][ T1373] get_tree_bdev+0x40a/0x690 [ 56.051257][ T1373] ? xfs_fs_inode_init_once+0xc0/0xc0 [ 56.056523][ T1373] vfs_get_tree+0x84/0x2c0 [ 56.060827][ T1373] do_mount+0xf93/0x1630 [ 56.064953][ T1373] ? rcu_read_lock_bh_held+0xc0/0xc0 [ 56.070129][ T1373] ? copy_mount_string+0x20/0x20 [ 56.074956][ T1373] ? _copy_from_user+0xbe/0x100 [ 56.079696][ T1373] ? memdup_user+0x4f/0x80 [ 56.083999][ T1373] __x64_sys_mount+0x15d/0x1b0 2m OK ] St[ 56.088654][ T1373] do_syscall_64+0x5f/0x310 [ 56.094437][ T1373] ? trace_hardirqs_off+0x12/0x1a0 [ 56.099439][ T1373] ? asm_exc_page_fault+0x8/0x30 [ 56.104267][ T1373] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 56.110055][ T1373] RIP: 0033:0x7f3bc2c8a9ee [ 56.114357][ T1373] Code: Bad RIP value. [ 56.118309][ T1373] RSP: 002b:00007fffd4675718 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 arted File Syste[ 56.126629][ T1373] RAX: ffffffffffffffda RBX: 000055a59d34c9c0 RCX: 00007f3bc2c8a9ee [ 56.135900][ T1373] RDX: 000055a59d34cba0 RSI: 000055a59d34cc00 RDI: 000055a59d34e900 [ 56.143779][ T1373] RBP: 00007f3bc3a36184 R08: 0000000000000000 R09: 0000000000000003 [ 56.151661][ T1373] R10: 00000000c0ed0000 R11: 0000000000000246 R12: 0000000000000000 [ 56.159541][ T1373] R13: 00000000c0ed0000 R14: 000055a59d34e900 R15: 000055a59d34cba0 [ 56.167422][ T1373] [ 56.169626][ T1373] [ 56.171831][ T1373] addr ffffc9000a7df1e0 is located in stack of task mount/1373 at offset 48 in frame: [ 56.181287][ T1373] submit_bio_noacct+0x0/0xeb0 submit_bio_noacct at block/blk-core.c:1198 [ 56.185939][ T1373] [ 56.188144][ T1373] this frame has 2 objects: m Check on /dev/[ 56.192532][ T1373] [32, 48) 'bio_list' [ 56.192534][ T1373] [96, 128) 'bio_list_on_stack' [ 56.197872][ T1373] [ 56.204894][ T1373] Memory state around the buggy address: [ 56.210420][ T1373] ffffc9000a7df080: f2 f2 f2 f2 f2 00 f2 f2 f2 f2 f2 f2 f2 00 00 00 [ 56.218389][ T1373] ffffc9000a7df100: 00 00 f2 f2 f2 00 00 00 00 00 00 00 00 00 00 00 disk/by-uuid/D10[ 56.226359][ T1373] >ffffc9000a7df180: 00 00 00 00 00 00 f1 f1 f1 f1 00 00 f2 f2 f2 f2 [ 56.235718][ T1373] ^ [ 56.242817][ T1373] ffffc9000a7df200: f2 f2 00 00 00 00 f3 f3 f3 f3 00 00 00 00 00 00 [ 56.250790][ T1373] ffffc9000a7df280: 00 00 00 00 00 00 00 00 00 00 f1 f1 f1 f1 00 f2 [ 56.258757][ T1373] ================================================================== > --- > block/blk-core.c | 131 +++++++++++++++++++++++++---------------------- > 1 file changed, 71 insertions(+), 60 deletions(-) > > diff --git a/block/blk-core.c b/block/blk-core.c > index 1caeb01e127768..b82f48c86e6f7a 100644 > --- a/block/blk-core.c > +++ b/block/blk-core.c > @@ -1085,6 +1085,74 @@ static blk_qc_t do_make_request(struct bio *bio) > return ret; > } > > +/* > + * The loop in this function may be a bit non-obvious, and so deserves some > + * explanation: > + * > + * - Before entering the loop, bio->bi_next is NULL (as all callers ensure > + * that), so we have a list with a single bio. > + * - We pretend that we have just taken it off a longer list, so we assign > + * bio_list to a pointer to the bio_list_on_stack, thus initialising the > + * bio_list of new bios to be added. ->submit_bio() may indeed add some more > + * bios through a recursive call to submit_bio_noacct. If it did, we find a > + * non-NULL value in bio_list and re-enter the loop from the top. > + * - In this case we really did just take the bio of the top of the list (no > + * pretending) and so remove it from bio_list, and call into ->submit_bio() > + * again. > + * > + * bio_list_on_stack[0] contains bios submitted by the current ->submit_bio. > + * bio_list_on_stack[1] contains bios that were submitted before the current > + * ->submit_bio_bio, but that haven't been processed yet. > + */ > +static blk_qc_t __submit_bio_noacct(struct bio *bio) > +{ > + struct bio_list bio_list_on_stack[2]; > + blk_qc_t ret = BLK_QC_T_NONE; > + > + BUG_ON(bio->bi_next); > + > + bio_list_init(&bio_list_on_stack[0]); > + current->bio_list = bio_list_on_stack; > + > + do { > + struct request_queue *q = bio->bi_disk->queue; > + struct bio_list lower, same; > + > + if (unlikely(bio_queue_enter(bio) != 0)) > + continue; > + > + /* > + * Create a fresh bio_list for all subordinate requests. > + */ > + bio_list_on_stack[1] = bio_list_on_stack[0]; > + bio_list_init(&bio_list_on_stack[0]); > + > + ret = do_make_request(bio); > + > + /* > + * Sort new bios into those for a lower level and those for the > + * same level. > + */ > + bio_list_init(&lower); > + bio_list_init(&same); > + while ((bio = bio_list_pop(&bio_list_on_stack[0])) != NULL) > + if (q == bio->bi_disk->queue) > + bio_list_add(&same, bio); > + else > + bio_list_add(&lower, bio); > + > + /* > + * Now assemble so we handle the lowest level first. > + */ > + bio_list_merge(&bio_list_on_stack[0], &lower); > + bio_list_merge(&bio_list_on_stack[0], &same); > + bio_list_merge(&bio_list_on_stack[0], &bio_list_on_stack[1]); > + } while ((bio = bio_list_pop(&bio_list_on_stack[0]))); > + > + current->bio_list = NULL; > + return ret; > +} > + > /** > * submit_bio_noacct - re-submit a bio to the block device layer for I/O > * @bio: The bio describing the location in memory and on the device. > @@ -1096,17 +1164,8 @@ static blk_qc_t do_make_request(struct bio *bio) > */ > blk_qc_t submit_bio_noacct(struct bio *bio) > { > - /* > - * bio_list_on_stack[0] contains bios submitted by the current > - * ->submit_bio. > - * bio_list_on_stack[1] contains bios that were submitted before the > - * current ->submit_bio_bio, but that haven't been processed yet. > - */ > - struct bio_list bio_list_on_stack[2]; > - blk_qc_t ret = BLK_QC_T_NONE; > - > if (!submit_bio_checks(bio)) > - goto out; > + return BLK_QC_T_NONE; > > /* > * We only want one ->submit_bio to be active at a time, else > @@ -1120,58 +1179,10 @@ blk_qc_t submit_bio_noacct(struct bio *bio) > */ > if (current->bio_list) { > bio_list_add(¤t->bio_list[0], bio); > - goto out; > + return BLK_QC_T_NONE; > } > > - /* following loop may be a bit non-obvious, and so deserves some > - * explanation. > - * Before entering the loop, bio->bi_next is NULL (as all callers > - * ensure that) so we have a list with a single bio. > - * We pretend that we have just taken it off a longer list, so > - * we assign bio_list to a pointer to the bio_list_on_stack, > - * thus initialising the bio_list of new bios to be > - * added. ->submit_bio() may indeed add some more bios > - * through a recursive call to submit_bio_noacct. If it > - * did, we find a non-NULL value in bio_list and re-enter the loop > - * from the top. In this case we really did just take the bio > - * of the top of the list (no pretending) and so remove it from > - * bio_list, and call into ->submit_bio() again. > - */ > - BUG_ON(bio->bi_next); > - bio_list_init(&bio_list_on_stack[0]); > - current->bio_list = bio_list_on_stack; > - do { > - struct request_queue *q = bio->bi_disk->queue; > - > - if (likely(bio_queue_enter(bio) == 0)) { > - struct bio_list lower, same; > - > - /* Create a fresh bio_list for all subordinate requests */ > - bio_list_on_stack[1] = bio_list_on_stack[0]; > - bio_list_init(&bio_list_on_stack[0]); > - ret = do_make_request(bio); > - > - /* sort new bios into those for a lower level > - * and those for the same level > - */ > - bio_list_init(&lower); > - bio_list_init(&same); > - while ((bio = bio_list_pop(&bio_list_on_stack[0])) != NULL) > - if (q == bio->bi_disk->queue) > - bio_list_add(&same, bio); > - else > - bio_list_add(&lower, bio); > - /* now assemble so we handle the lowest level first */ > - bio_list_merge(&bio_list_on_stack[0], &lower); > - bio_list_merge(&bio_list_on_stack[0], &same); > - bio_list_merge(&bio_list_on_stack[0], &bio_list_on_stack[1]); > - } > - bio = bio_list_pop(&bio_list_on_stack[0]); > - } while (bio); > - current->bio_list = NULL; /* deactivate */ > - > -out: > - return ret; > + return __submit_bio_noacct(bio); > } > EXPORT_SYMBOL(submit_bio_noacct); > > -- > 2.26.2 >
