From 698f744aa858e4a5bfcef3f5e0cfc57a15d5b64a Mon Sep 17 00:00:00 2001 From: Oded Gabbay Date: Fri, 20 Aug 2021 14:24:48 +0300 Subject: habanalabs: never copy_from_user inside spinlock copy_from_user might sleep so we can never call it when we have a spinlock. Moreover, it is not necessary in waiting for user interrupt, because if multiple threads will call this function on the same interrupt, each one will have it's own fence object inside the driver. The user address might be the same, but it doesn't really matter to us, as we only read from it. Signed-off-by: Oded Gabbay --- .../misc/habanalabs/common/command_submission.c | 35 ++++++++-------------- 1 file changed, 12 insertions(+), 23 deletions(-) diff --git a/drivers/misc/habanalabs/common/command_submission.c b/drivers/misc/habanalabs/common/command_submission.c index a97bb27ebb90..7b0516cf808b 100644 --- a/drivers/misc/habanalabs/common/command_submission.c +++ b/drivers/misc/habanalabs/common/command_submission.c @@ -2740,14 +2740,10 @@ static int _hl_interrupt_wait_ioctl(struct hl_device *hdev, struct hl_ctx *ctx, else interrupt = &hdev->user_interrupt[interrupt_offset]; - spin_lock_irqsave(&interrupt->wait_list_lock, flags); - - if (copy_from_user(&completion_value, u64_to_user_ptr(user_address), - 4)) { - dev_err(hdev->dev, - "Failed to copy completion value from user\n"); + if (copy_from_user(&completion_value, u64_to_user_ptr(user_address), 4)) { + dev_err(hdev->dev, "Failed to copy completion value from user\n"); rc = -EFAULT; - goto unlock_and_free_fence; + goto free_fence; } if (completion_value >= target_value) @@ -2756,42 +2752,35 @@ static int _hl_interrupt_wait_ioctl(struct hl_device *hdev, struct hl_ctx *ctx, *status = CS_WAIT_STATUS_BUSY; if (!timeout_us || (*status == CS_WAIT_STATUS_COMPLETED)) - goto unlock_and_free_fence; + goto free_fence; /* Add pending user interrupt to relevant list for the interrupt * handler to monitor */ + spin_lock_irqsave(&interrupt->wait_list_lock, flags); list_add_tail(&pend->wait_list_node, &interrupt->wait_list_head); spin_unlock_irqrestore(&interrupt->wait_list_lock, flags); wait_again: /* Wait for interrupt handler to signal completion */ - completion_rc = - wait_for_completion_interruptible_timeout( - &pend->fence.completion, timeout); + completion_rc = wait_for_completion_interruptible_timeout(&pend->fence.completion, + timeout); /* If timeout did not expire we need to perform the comparison. * If comparison fails, keep waiting until timeout expires */ if (completion_rc > 0) { - spin_lock_irqsave(&interrupt->wait_list_lock, flags); - - if (copy_from_user(&completion_value, - u64_to_user_ptr(user_address), 4)) { - - spin_unlock_irqrestore(&interrupt->wait_list_lock, flags); - - dev_err(hdev->dev, - "Failed to copy completion value from user\n"); + if (copy_from_user(&completion_value, u64_to_user_ptr(user_address), 4)) { + dev_err(hdev->dev, "Failed to copy completion value from user\n"); rc = -EFAULT; goto remove_pending_user_interrupt; } if (completion_value >= target_value) { - spin_unlock_irqrestore(&interrupt->wait_list_lock, flags); *status = CS_WAIT_STATUS_COMPLETED; } else { + spin_lock_irqsave(&interrupt->wait_list_lock, flags); reinit_completion(&pend->fence.completion); timeout = completion_rc; @@ -2811,9 +2800,9 @@ wait_again: remove_pending_user_interrupt: spin_lock_irqsave(&interrupt->wait_list_lock, flags); list_del(&pend->wait_list_node); - -unlock_and_free_fence: spin_unlock_irqrestore(&interrupt->wait_list_lock, flags); + +free_fence: kfree(pend); hl_ctx_put(ctx); -- cgit v1.2.3-59-g8ed1b