From 176d23a77edb7f10611bf61f1196abde119c7694 Mon Sep 17 00:00:00 2001 From: Oded Gabbay Date: Fri, 20 Aug 2021 13:49:39 +0300 Subject: [PATCH] habanalabs: disable IRQ in user interrupts spinlock Because this spinlock is taken in an interrupt handler, we must use the spin_lock_irqsave/irqrestore version to disable the interrupts on the local CPU. Otherwise, we can have a potential deadlock (if the interrupt handler is scheduled to run on the same cpu that the code who took the lock was running on). Signed-off-by: Oded Gabbay --- .../misc/habanalabs/common/command_submission.c | 25 +++++++++++----------- 1 file changed, 13 insertions(+), 12 deletions(-) diff --git a/drivers/misc/habanalabs/common/command_submission.c b/drivers/misc/habanalabs/common/command_submission.c index 3a67265..8a2f75d 100644 --- a/drivers/misc/habanalabs/common/command_submission.c +++ b/drivers/misc/habanalabs/common/command_submission.c @@ -923,13 +923,14 @@ static void wake_pending_user_interrupt_threads(struct hl_user_interrupt *interrupt) { struct hl_user_pending_interrupt *pend; + unsigned long flags; - spin_lock(&interrupt->wait_list_lock); + spin_lock_irqsave(&interrupt->wait_list_lock, flags); list_for_each_entry(pend, &interrupt->wait_list_head, wait_list_node) { pend->fence.error = -EIO; complete_all(&pend->fence.completion); } - spin_unlock(&interrupt->wait_list_lock); + spin_unlock_irqrestore(&interrupt->wait_list_lock, flags); } void hl_release_pending_user_interrupts(struct hl_device *hdev) @@ -2714,9 +2715,9 @@ static int _hl_interrupt_wait_ioctl(struct hl_device *hdev, struct hl_ctx *ctx, { struct hl_user_pending_interrupt *pend; struct hl_user_interrupt *interrupt; - unsigned long timeout; - long completion_rc; + unsigned long timeout, flags; u32 completion_value; + long completion_rc; int rc = 0; if (timeout_us == U32_MAX) @@ -2739,7 +2740,7 @@ static int _hl_interrupt_wait_ioctl(struct hl_device *hdev, struct hl_ctx *ctx, else interrupt = &hdev->user_interrupt[interrupt_offset]; - spin_lock(&interrupt->wait_list_lock); + spin_lock_irqsave(&interrupt->wait_list_lock, flags); if (!hl_device_operational(hdev, NULL)) { rc = -EPERM; goto unlock_and_free_fence; @@ -2765,7 +2766,7 @@ static int _hl_interrupt_wait_ioctl(struct hl_device *hdev, struct hl_ctx *ctx, * handler to monitor */ list_add_tail(&pend->wait_list_node, &interrupt->wait_list_head); - spin_unlock(&interrupt->wait_list_lock); + spin_unlock_irqrestore(&interrupt->wait_list_lock, flags); wait_again: /* Wait for interrupt handler to signal completion */ @@ -2777,12 +2778,12 @@ wait_again: * If comparison fails, keep waiting until timeout expires */ if (completion_rc > 0) { - spin_lock(&interrupt->wait_list_lock); + spin_lock_irqsave(&interrupt->wait_list_lock, flags); if (copy_from_user(&completion_value, u64_to_user_ptr(user_address), 4)) { - spin_unlock(&interrupt->wait_list_lock); + spin_unlock_irqrestore(&interrupt->wait_list_lock, flags); dev_err(hdev->dev, "Failed to copy completion value from user\n"); @@ -2792,13 +2793,13 @@ wait_again: } if (completion_value >= target_value) { - spin_unlock(&interrupt->wait_list_lock); + spin_unlock_irqrestore(&interrupt->wait_list_lock, flags); *status = CS_WAIT_STATUS_COMPLETED; } else { reinit_completion(&pend->fence.completion); timeout = completion_rc; - spin_unlock(&interrupt->wait_list_lock); + spin_unlock_irqrestore(&interrupt->wait_list_lock, flags); goto wait_again; } } else if (completion_rc == -ERESTARTSYS) { @@ -2812,11 +2813,11 @@ wait_again: } remove_pending_user_interrupt: - spin_lock(&interrupt->wait_list_lock); + spin_lock_irqsave(&interrupt->wait_list_lock, flags); list_del(&pend->wait_list_node); unlock_and_free_fence: - spin_unlock(&interrupt->wait_list_lock); + spin_unlock_irqrestore(&interrupt->wait_list_lock, flags); kfree(pend); hl_ctx_put(ctx); -- 2.7.4