From ce8548ec056022c4feccacc9eb09a4e8619bdefa Mon Sep 17 00:00:00 2001 From: Sagar Kamble Date: Tue, 3 Aug 2021 09:11:33 +0530 Subject: gpu: nvgpu: fix clk_arb completion file private data access race clk_arb completion file descriptor can get closed immediately after poll finishes in the work item gp10b_clk_arb_run_arbiter_cb. In that case, the refcount for nvgpu_clk_dev can become zero in the work item and can lead to invalid access while removing nvgpu_clk_dev from the lists. Remove nvgpu_clk_dev from the list before dropping the reference to it. Also, delete the nvgpu_clk_dev in completion file release handler within the session and requests spinlocks to avoid race with gp10b_clk_arb_run_arbiter_cb using it. bug 200757277 Change-Id: I054eee547f2a6fa633d7ef55df216ec36647a826 Signed-off-by: Sagar Kamble Reviewed-on: https://git-master.nvidia.com/r/c/linux-nvgpu/+/2569522 Tested-by: mobile promotions Reviewed-by: Debarshi Dutta Reviewed-by: Deepak Nibade Reviewed-by: Bibek Basu Reviewed-by: mobile promotions --- drivers/gpu/nvgpu/os/linux/ioctl_clk_arb.c | 17 +++++++++++++---- 1 file changed, 13 insertions(+), 4 deletions(-) (limited to 'drivers/gpu/nvgpu/os') diff --git a/drivers/gpu/nvgpu/os/linux/ioctl_clk_arb.c b/drivers/gpu/nvgpu/os/linux/ioctl_clk_arb.c index 477222dc..9f321021 100644 --- a/drivers/gpu/nvgpu/os/linux/ioctl_clk_arb.c +++ b/drivers/gpu/nvgpu/os/linux/ioctl_clk_arb.c @@ -1,5 +1,5 @@ /* - * Copyright (c) 2016-2018, NVIDIA CORPORATION. All rights reserved. + * Copyright (c) 2016-2021, NVIDIA CORPORATION. All rights reserved. * * This software is licensed under the terms of the GNU General Public * License version 2, as published by the Free Software Foundation, and @@ -51,19 +51,28 @@ static int nvgpu_clk_arb_release_completion_dev(struct inode *inode, { struct nvgpu_clk_dev *dev = filp->private_data; struct nvgpu_clk_session *session = dev->session; + struct gk20a *g = session->g; + struct nvgpu_clk_arb *arb = g->clk_arb; + clk_arb_dbg(g, " "); - clk_arb_dbg(session->g, " "); + nvgpu_spinlock_acquire(&session->session_lock); + nvgpu_spinlock_acquire(&arb->requests_lock); + + nvgpu_list_del(&dev->node); + + nvgpu_spinlock_release(&arb->requests_lock); + nvgpu_spinlock_release(&session->session_lock); /* This is done to account for the extra refcount taken in * nvgpu_clk_arb_commit_request_fd without events support in iGPU */ - if (!session->g->clk_arb->clk_arb_events_supported) { + if (!arb->clk_arb_events_supported) { nvgpu_ref_put(&dev->refcount, nvgpu_clk_arb_free_fd); } - nvgpu_ref_put(&session->refcount, nvgpu_clk_arb_free_session); nvgpu_ref_put(&dev->refcount, nvgpu_clk_arb_free_fd); + nvgpu_ref_put(&session->refcount, nvgpu_clk_arb_free_session); return 0; } -- cgit v1.2.2