From b03fe816d7b2675afdb4c1d10fe7658a5f2b2f82 Mon Sep 17 00:00:00 2001 From: Rahul Rameshbabu Date: Tue, 12 Nov 2024 15:01:16 -0800 Subject: [PATCH 6/6] nvidia-drm: Set FOP_UNSIGNED_OFFSET for nv_drm_fops.fop_flags if present Linux kernel commit 641bb4394f40 ("fs: move FMODE_UNSIGNED_OFFSET to fop_flags") introduced a new .fop_flags define, FOP_UNSIGNED_OFFSET, for struct file_operations. A check in drm_open_helper was added to ensure DRM device drivers mark that all file offsets passed for working with DRM fs nodes are unsigned values. If a DRM device driver fails to set this static member, opening DRM device nodes (/dev/dri/card*) will fail. This commit will land in Linux kernel v6.12. To ensure DRM clients will continue to function with kernel v6.12 and above, set FOP_UNSIGNED_OFFSET for nv_drm_fops.fop_flags if FOP_UNSIGNED_OFFSET is present in the linux kernel headers being built against. Without doing so, userspace DRM clients will fail to function. An example is being unable to launch Wayland compositors. KWin logs without this change: kwin_core: Failed to open /dev/dri/card1 device (Invalid argument) kwin_wayland_drm: failed to open drm device at "/dev/dri/card1" kwin_core: Failed to open /dev/dri/card0 device (Invalid argument) kwin_wayland_drm: failed to open drm device at "/dev/dri/card0" kwin_wayland_drm: No suitable DRM devices have been found Linux kernel warning generated without this change: [Oct 2 02:15] ------------[ cut here ]------------ [ +0.000009] WARNING: CPU: 2 PID: 464 at drivers/gpu/drm/drm_file.c:312 drm_open_helper+0x134/0x150 [ +0.000108] Unloaded tainted modules: nvidia(OE):1 nvidia_modeset(OE):1 nvidia_drm(OE):1 [last unloaded: ttm] [ +0.000024] CPU: 2 UID: 0 PID: 464 Comm: systemd-logind Tainted: G OE 6.12.0-rc1-next-20241001-sound+ #10 c8090f98b0209abebde89ba1e4c08c75331eef4d [ +0.000016] Tainted: [O]=OOT_MODULE, [E]=UNSIGNED_MODULE [ +0.000004] Hardware name: System manufacturer PRIME Z390-A/PRIME Z390-A, BIOS 0224 08/14/2018 [ +0.000005] RIP: 0010:drm_open_helper+0x134/0x150 [ +0.000005] Call Trace: [ +0.000006] [ +0.000004] ? drm_open_helper+0x134/0x150 [ +0.000008] ? __warn.cold+0x93/0xf6 [ +0.000011] ? drm_open_helper+0x134/0x150 [ +0.000009] ? report_bug+0xff/0x140 [ +0.000009] ? handle_bug+0x58/0x90 [ +0.000010] ? exc_invalid_op+0x17/0x70 [ +0.000010] ? asm_exc_invalid_op+0x1a/0x20 [ +0.000018] ? drm_open_helper+0x134/0x150 [ +0.000008] drm_open+0x73/0x110 [ +0.000007] drm_stub_open+0x9b/0xd0 [ +0.000009] chrdev_open+0xb0/0x230 [ +0.000014] ? __pfx_chrdev_open+0x10/0x10 [ +0.000011] do_dentry_open+0x14c/0x4a0 [ +0.000013] vfs_open+0x2e/0xe0 [ +0.000009] path_openat+0x82f/0x13f0 [ +0.000016] do_filp_open+0xc4/0x170 [ +0.000020] do_sys_openat2+0xae/0xe0 [ +0.000010] __x64_sys_openat+0x55/0xa0 [ +0.000009] do_syscall_64+0x82/0x190 [ +0.000008] ? do_readlinkat+0xc5/0x180 [ +0.000008] ? syscall_exit_to_user_mode+0x37/0x1c0 [ +0.000010] ? do_syscall_64+0x8e/0x190 [ +0.000007] ? do_sys_openat2+0x9c/0xe0 [ +0.000009] ? syscall_exit_to_user_mode+0x37/0x1c0 [ +0.000008] ? do_syscall_64+0x8e/0x190 [ +0.000007] ? syscall_exit_to_user_mode+0x37/0x1c0 [ +0.000007] ? do_syscall_64+0x8e/0x190 [ +0.000006] ? do_syscall_64+0x8e/0x190 [ +0.000007] entry_SYSCALL_64_after_hwframe+0x76/0x7e [ +0.000012] RIP: 0033:0x7f90c1cec2e3 [ +0.000004] ---[ end trace 0000000000000000 ]--- Signed-off-by: Rahul Rameshbabu --- kernel-open/nvidia-drm/nvidia-drm-drv.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/kernel-open/nvidia-drm/nvidia-drm-drv.c b/kernel-open/nvidia-drm/nvidia-drm-drv.c index 8cb94219..16f0d13e 100644 --- a/kernel-open/nvidia-drm/nvidia-drm-drv.c +++ b/kernel-open/nvidia-drm/nvidia-drm-drv.c @@ -1711,6 +1711,10 @@ static const struct file_operations nv_drm_fops = { .read = drm_read, .llseek = noop_llseek, + +#if defined(FOP_UNSIGNED_OFFSET) + .fop_flags = FOP_UNSIGNED_OFFSET, +#endif }; static const struct drm_ioctl_desc nv_drm_ioctls[] = { -- 2.47.0 Signed-off-by: Rahul Rameshbabu --- kernel-open/nvidia-drm/nvidia-drm-drv.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/kernel/nvidia-drm/nvidia-drm-drv.c b/kernel/nvidia-drm/nvidia-drm-drv.c index 8cb94219..16f0d13e 100644 --- a/kernel/nvidia-drm/nvidia-drm-drv.c +++ b/kernel/nvidia-drm/nvidia-drm-drv.c @@ -1711,6 +1711,10 @@ static const struct file_operations nv_drm_fops = { .read = drm_read, .llseek = noop_llseek, + +#if defined(FOP_UNSIGNED_OFFSET) + .fop_flags = FOP_UNSIGNED_OFFSET, +#endif }; static const struct drm_ioctl_desc nv_drm_ioctls[] = { -- 2.47.0