hulk inclusion
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I6QMTU

--------------------------------

Recently, a null-ptr-deref problem occur when submitting IO to nvme disk:

[34432.226539] ==========================================================
[34432.226579] BUG: KASAN: null-ptr-deref in
trace_event_raw_event_nvme_complete_rq+0x13c/0x270 [nvme_core]
[34432.226584] Read of size 2 at addr 0000000000000002 by task loop0/32
[34432.226586]
[34432.226594] CPU: 0 PID: 3242729 Comm: loop0 Kdump: loaded Tainted:
[34432.226598] Hardware name: Huawei TaiShan 2280 V2/BC82AMDD
[34432.226602] Call trace:
[34432.226610]  dump_backtrace+0x0/0x2fc
[34432.226615]  show_stack+0x20/0x30
[34432.226623]  dump_stack+0x104/0x17c
[34432.226630]  __kasan_report+0x138/0x140
[34432.226634]  kasan_report+0x44/0xdc
[34432.226639]  __asan_load2+0x90/0xd0
[34432.226662]  trace_event_raw_event_nvme_complete_rq+0x13c/0x270
[34432.226684]  nvme_complete_rq+0x228/0x480 [nvme_core]
[34432.226698]  nvme_pci_complete_rq+0x184/0x1b4 [nvme]
[34432.226706]  nvme_irq+0x270/0x500 [nvme]
[34432.226714]  __handle_irq_event_percpu+0x8c/0x324
[34432.226719]  handle_irq_event_percpu+0x88/0x11c
[34432.226724]  handle_irq_event+0x110/0x2b0
[34432.226729]  handle_fasteoi_irq+0x1e4/0x3f4
[34432.226734]  __handle_domain_irq+0xbc/0x130
[34432.226739]  gic_handle_irq+0x78/0x460
[34432.226743]  el1_irq+0xb8/0x140
[34432.226750]  __slab_alloc+0x38/0x70
[34432.226756]  kmem_cache_alloc+0x6b8/0x904
[34432.226762]  mempool_alloc_slab+0x3c/0x60
[34432.226766]  mempool_alloc+0xf0/0x440
[34432.226772]  bio_alloc_bioset+0x208/0x2f0
[34432.226899]  io_submit_init_bio+0x3c/0x190 [ext4]
[34432.226991]  ext4_bio_write_page+0x540/0xbd0 [ext4]
[34432.227082]  mpage_submit_page+0xb0/0x120 [ext4]
[34432.227173]  mpage_process_page_bufs+0x25c/0x2b4 [ext4]
[34432.227265]  mpage_prepare_extent_to_map+0x3b8/0x75c [ext4]
[34432.227356]  ext4_writepages+0x454/0xcb4 [ext4]
[34432.227361]  do_writepages+0xc4/0x1c0
...

This can be reproduced by following steps:
1) modprobe nvme
2) echo nvme:* > /sys/kernel/debug/tracing/set_event
3) dd if=/dev/random of=/dev/nvmexxx bs=1M count=1024

Generating command_id by nvme_cid() in trace event instead of
nvme_req(req)->cmd->common.command_id can fix it since
nvme_req(req)->cmd can be NULL in sometimes.

Fixes: bbd033cb ("nvme: use command_id instead of req->tag in trace_nvme_complete_rq()")
Signed-off-by: NLi Lingfeng <lilingfeng3@huawei.com>
Reviewed-by: NHou Tao <houtao1@huawei.com>
Signed-off-by: NJialin Zhang <zhangjialin11@huawei.com>