Without this patch, if we have multi PCIe devices, and one of them has AER error, aer_recover_work_func() -> kfifo_get() will traverse the whole kfifo which has wrong element number(16). If one null element's uninitialized memory matches another PCIe device(0000:01:00.0), we may get the below call trace. It is unusual, but indeed happened on my board: QDF2400. # lspci 0000:00:00.0 PCI bridge: 0000:01:00.0 Ethernet controller: 0004:00:00.0 PCI bridge: 0004:01:00.0 Ethernet controller: 0005:00:00.0 PCI bridge: 0005:01:00.0 Ethernet controller: Call trace: [Hardware Error]: Hardware error from APEI Generic Hardware Error Source: 5 [Hardware Error]: It has been corrected by h/w and requires no further action [Hardware Error]: event severity: corrected [Hardware Error]: precise tstamp: 2018-11-29 09:23:16 [Hardware Error]: Error 0, type: corrected [Hardware Error]: section_type: PCIe error [Hardware Error]: port_type: 4, root port [Hardware Error]: version: 3.0 [Hardware Error]: command: 0x0407, status: 0x0010 [Hardware Error]: device_id: 0004:00:00.0 [Hardware Error]: slot: 0 [Hardware Error]: secondary_bus: 0x01 [Hardware Error]: vendor_id: 0x17cb, device_id: 0x0401 [Hardware Error]: class_code: 000406 [Hardware Error]: bridge: secondary_status: 0x0000, control: 0x0000 AER recover: find pci_dev for 0004:00:00:0 pcieport 0004:00:00.0: aer_status: 0x00000001, aer_mask: 0x0000e000 pcieport 0004:00:00.0: [ 0] RxErr (First) pcieport 0004:00:00.0: aer_layer=Physical Layer, aer_agent=Receiver ID AER recover: Can not find pci_dev for a38f:00:18:2 AER recover: Can not find pci_dev for 0857:1c:03:5 AER recover: Can not find pci_dev for 62d2:80:19:6 AER recover: Can not find pci_dev for 0857:f8:03:4 AER recover: Can not find pci_dev for 0907:78:07:1 AER recover: Can not find pci_dev for 0000:00:00:1 AER recover: Can not find pci_dev for 0907:00:00:0 AER recover: Can not find pci_dev for 0000:00:00:1 AER recover: find pci_dev for 0000:01:00:0 Unable to handle kernel paging request at virtual address 0000000000813004 Mem abort info: ESR = 0x96000007 Exception class = DABT (current EL), IL = 32 bits SET = 0, FnV = 0 EA = 0, S1PTW = 0 Data abort info: ISV = 0, ISS = 0x00000007 CM = 0, WnR = 0 user pgtable: 64k pages, 48-bit VAs, pgdp = 000000000dce9024 [0000000000813004] pgd=0000001727260003, pud=0000001727260003 pmd=0000001727290003, pte=0000000000000000 Internal error: Oops: 96000007 [#1] SMP Workqueue: events aer_recover_work_func pstate: 20400005 (nzCv daif +PAN -UAO) pc : cper_print_aer+0x4c/0x290 lr : aer_recover_work_func+0x110/0x150 sp : ffff8017ca59fca0 x29: ffff8017ca59fca0 x28: ffff8017ca841000 x27: ffff8017ca841000 x26: 0000000000000001 x25: 0000000000813000 x24: 0000000000000040 x23: 0000000000000040 x22: ffff000008d5f830 x21: ffff0000090f1f10 x20: ffff0000090f1e98 x19: 0000000000000000 x18: ffffffffffffffff x17: 0000000000000001 x16: 0000000000000007 x15: ffff000009073708 x14: ffff0000891e8faf x13: ffff0000091e8fbd x12: 2c726579614c206c x11: ffff00000909b000 x10: 0000000005f5e0ff x9 : ffff8017ca59fa10 x8 : ffff000009073978 x7 : ffff0000091e8a40 x6 : 0000000000000518 x5 : 0000000000000001 x4 : ffff8017ff9710b8 x3 : ffff8017ff9710b8 x2 : 0000000000813000 x1 : 0000000000000000 x0 : ffff000009073708 Process kworker/11:1 (pid: 232, stack limit = 0x00000000060ad7e1) Call trace: cper_print_aer+0x4c/0x290 aer_recover_work_func+0x110/0x150 process_one_work+0x1ac/0x3f0 worker_thread+0x54/0x430 kthread+0x104/0x130 ret_from_fork+0x10/0x18 Code: f9400001 f90057a1 d2800001 54000f40 (2940e334) SMP: stopping secondary CPUs Starting crashdump kernel... Bye! This email is intended only for the named addressee. It may contain information that is confidential/private, legally privileged, or copyright-protected, and you should handle it accordingly. If you are not the intended recipient, you do not have legal rights to retain, copy, or distribute this email or its contents, and should promptly delete the email and all electronic copies in your system; do not retain copies in any media. If you have received this email in error, please notify the sender promptly. Thank you.
