From: Bart Van Assche <bvanassche@xxxxxxx> [ Upstream commit 2acd76e7b8596e307fcec8fc6bc5fe5ab174749a ] Prevent that both the interrupt handler and the reset handler try to complete a request at the same time. This patch is the result of an analysis of the following crash: Unable to handle kernel NULL pointer dereference at virtual address 0000000000000120 CPU: 0 PID: 0 Comm: swapper/0 Tainted: G OE 5.10.107-android13-4-00051-g1e48e8970cca-ab8664745 #1 pc : ufshcd_release_scsi_cmd+0x30/0x46c lr : __ufshcd_transfer_req_compl+0x4fc/0x9c0 Call trace: ufshcd_release_scsi_cmd+0x30/0x46c __ufshcd_transfer_req_compl+0x4fc/0x9c0 ufshcd_poll+0xf0/0x208 ufshcd_sl_intr+0xb8/0xf0 ufshcd_intr+0x168/0x2f4 __handle_irq_event_percpu+0xa0/0x30c handle_irq_event+0x84/0x178 handle_fasteoi_irq+0x150/0x2e8 __handle_domain_irq+0x114/0x1e4 gic_handle_irq.31846+0x58/0x300 el1_irq+0xe4/0x1c0 cpuidle_enter_state+0x3ac/0x8c4 do_idle+0x2fc/0x55c cpu_startup_entry+0x84/0x90 kernel_init+0x0/0x310 start_kernel+0x0/0x608 start_kernel+0x4ec/0x608 Link: https://lore.kernel.org/r/20220613214442.212466-4-bvanassche@xxxxxxx Reviewed-by: Stanley Chu <stanley.chu@xxxxxxxxxxxx> Reviewed-by: Adrian Hunter <adrian.hunter@xxxxxxxxx> Signed-off-by: Bart Van Assche <bvanassche@xxxxxxx> Signed-off-by: Martin K. Petersen <martin.petersen@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- drivers/scsi/ufs/ufshcd.c | 28 +++++++++++++++++++--------- 1 file changed, 19 insertions(+), 9 deletions(-) diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c index f08586a4470c..02a122738686 100644 --- a/drivers/scsi/ufs/ufshcd.c +++ b/drivers/scsi/ufs/ufshcd.c @@ -6970,14 +6970,14 @@ int ufshcd_exec_raw_upiu_cmd(struct ufs_hba *hba, } /** - * ufshcd_eh_device_reset_handler - device reset handler registered to - * scsi layer. + * ufshcd_eh_device_reset_handler() - Reset a single logical unit. * @cmd: SCSI command pointer * * Returns SUCCESS/FAILED */ static int ufshcd_eh_device_reset_handler(struct scsi_cmnd *cmd) { + unsigned long flags, pending_reqs = 0, not_cleared = 0; struct Scsi_Host *host; struct ufs_hba *hba; u32 pos; @@ -6996,14 +6996,24 @@ static int ufshcd_eh_device_reset_handler(struct scsi_cmnd *cmd) } /* clear the commands that were pending for corresponding LUN */ - for_each_set_bit(pos, &hba->outstanding_reqs, hba->nutrs) { - if (hba->lrb[pos].lun == lun) { - err = ufshcd_clear_cmds(hba, 1U << pos); - if (err) - break; - __ufshcd_transfer_req_compl(hba, 1U << pos); - } + spin_lock_irqsave(&hba->outstanding_lock, flags); + for_each_set_bit(pos, &hba->outstanding_reqs, hba->nutrs) + if (hba->lrb[pos].lun == lun) + __set_bit(pos, &pending_reqs); + hba->outstanding_reqs &= ~pending_reqs; + spin_unlock_irqrestore(&hba->outstanding_lock, flags); + + if (ufshcd_clear_cmds(hba, pending_reqs) < 0) { + spin_lock_irqsave(&hba->outstanding_lock, flags); + not_cleared = pending_reqs & + ufshcd_readl(hba, REG_UTP_TRANSFER_REQ_DOOR_BELL); + hba->outstanding_reqs |= not_cleared; + spin_unlock_irqrestore(&hba->outstanding_lock, flags); + + dev_err(hba->dev, "%s: failed to clear requests %#lx\n", + __func__, not_cleared); } + __ufshcd_transfer_req_compl(hba, pending_reqs & ~not_cleared); out: hba->req_abort_count = 0; -- 2.35.1
