On 12/23/23 21:25, Zack Rusin wrote: > Switch to a new plane state requires unreferencing of all held surfaces. > In the work required for mob cursors the mapped surfaces started being > cached but the variable indicating whether the surface is currently > mapped was not being reset. This leads to crashes as the duplicated > state, incorrectly, indicates the that surface is mapped even when > no surface is present. That's because after unreferencing the surface > it's perfectly possible for the plane to be backed by a bo instead of a > surface. > > Reset the surface mapped flag when unreferencing the plane state surface > to fix null derefs in cleanup. Fixes crashes in KDE KWin 6.0 on Wayland: > > Oops: 0000 [#1] PREEMPT SMP PTI > CPU: 4 PID: 2533 Comm: kwin_wayland Not tainted 6.7.0-rc3-vmwgfx #2 > Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 11/12/2020 > RIP: 0010:vmw_du_cursor_plane_cleanup_fb+0x124/0x140 [vmwgfx] > Code: 00 00 00 75 3a 48 83 c4 10 5b 5d c3 cc cc cc cc 48 8b b3 a8 00 00 00 48 c7 c7 99 90 43 c0 e8 93 c5 db ca 48 8b 83 a8 00 00 00 <48> 8b 78 28 e8 e3 f> > RSP: 0018:ffffb6b98216fa80 EFLAGS: 00010246 > RAX: 0000000000000000 RBX: ffff969d84cdcb00 RCX: 0000000000000027 > RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffff969e75f21600 > RBP: ffff969d4143dc50 R08: 0000000000000000 R09: ffffb6b98216f920 > R10: 0000000000000003 R11: ffff969e7feb3b10 R12: 0000000000000000 > R13: 0000000000000000 R14: 000000000000027b R15: ffff969d49c9fc00 > FS: 00007f1e8f1b4180(0000) GS:ffff969e75f00000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 0000000000000028 CR3: 0000000104006004 CR4: 00000000003706f0 > Call Trace: > <TASK> > ? __die+0x23/0x70 > ? page_fault_oops+0x171/0x4e0 > ? exc_page_fault+0x7f/0x180 > ? asm_exc_page_fault+0x26/0x30 > ? vmw_du_cursor_plane_cleanup_fb+0x124/0x140 [vmwgfx] > drm_atomic_helper_cleanup_planes+0x9b/0xc0 > commit_tail+0xd1/0x130 > drm_atomic_helper_commit+0x11a/0x140 > drm_atomic_commit+0x97/0xd0 > ? __pfx___drm_printfn_info+0x10/0x10 > drm_atomic_helper_update_plane+0xf5/0x160 > drm_mode_cursor_universal+0x10e/0x270 > drm_mode_cursor_common+0x102/0x230 > ? __pfx_drm_mode_cursor2_ioctl+0x10/0x10 > drm_ioctl_kernel+0xb2/0x110 > drm_ioctl+0x26d/0x4b0 > ? __pfx_drm_mode_cursor2_ioctl+0x10/0x10 > ? __pfx_drm_ioctl+0x10/0x10 > vmw_generic_ioctl+0xa4/0x110 [vmwgfx] > __x64_sys_ioctl+0x94/0xd0 > do_syscall_64+0x61/0xe0 > ? __x64_sys_ioctl+0xaf/0xd0 > ? syscall_exit_to_user_mode+0x2b/0x40 > ? do_syscall_64+0x70/0xe0 > ? __x64_sys_ioctl+0xaf/0xd0 > ? syscall_exit_to_user_mode+0x2b/0x40 > ? do_syscall_64+0x70/0xe0 > ? exc_page_fault+0x7f/0x180 > entry_SYSCALL_64_after_hwframe+0x6e/0x76 > RIP: 0033:0x7f1e93f279ed > Code: 04 25 28 00 00 00 48 89 45 c8 31 c0 48 8d 45 10 c7 45 b0 10 00 00 00 48 89 45 b8 48 8d 45 d0 48 89 45 c0 b8 10 00 00 00 0f 05 <89> c2 3d 00 f0 ff f> > RSP: 002b:00007ffca0faf600 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 > RAX: ffffffffffffffda RBX: 000055db876ed2c0 RCX: 00007f1e93f279ed > RDX: 00007ffca0faf6c0 RSI: 00000000c02464bb RDI: 0000000000000015 > RBP: 00007ffca0faf650 R08: 000055db87184010 R09: 0000000000000007 > R10: 000055db886471a0 R11: 0000000000000246 R12: 00007ffca0faf6c0 > R13: 00000000c02464bb R14: 0000000000000015 R15: 00007ffca0faf790 > </TASK> > Modules linked in: snd_seq_dummy snd_hrtimer nf_conntrack_netbios_ns nf_conntrack_broadcast nft_fib_inet nft_fib_ipv4 nft_fib_ipv6 nft_fib nft_reject_ine> > CR2: 0000000000000028 > ---[ end trace 0000000000000000 ]--- > RIP: 0010:vmw_du_cursor_plane_cleanup_fb+0x124/0x140 [vmwgfx] > Code: 00 00 00 75 3a 48 83 c4 10 5b 5d c3 cc cc cc cc 48 8b b3 a8 00 00 00 48 c7 c7 99 90 43 c0 e8 93 c5 db ca 48 8b 83 a8 00 00 00 <48> 8b 78 28 e8 e3 f> > RSP: 0018:ffffb6b98216fa80 EFLAGS: 00010246 > RAX: 0000000000000000 RBX: ffff969d84cdcb00 RCX: 0000000000000027 > RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffff969e75f21600 > RBP: ffff969d4143dc50 R08: 0000000000000000 R09: ffffb6b98216f920 > R10: 0000000000000003 R11: ffff969e7feb3b10 R12: 0000000000000000 > R13: 0000000000000000 R14: 000000000000027b R15: ffff969d49c9fc00 > FS: 00007f1e8f1b4180(0000) GS:ffff969e75f00000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 0000000000000028 CR3: 0000000104006004 CR4: 00000000003706f0 > > Signed-off-by: Zack Rusin <zack.rusin@xxxxxxxxxxxx> > Fixes: 485d98d472d5 ("drm/vmwgfx: Add support for CursorMob and CursorBypass 4") > Reported-by: Stefan Hoffmeister <stefan.hoffmeister@xxxxxxxxx> > Closes: https://gitlab.freedesktop.org/drm/misc/-/issues/34 > Cc: Martin Krastev <martin.krastev@xxxxxxxxxxxx> > Cc: Maaz Mombasawala <maaz.mombasawala@xxxxxxxxxxxx> > Cc: Ian Forbes <ian.forbes@xxxxxxxxxxxx> > Cc: Broadcom internal kernel review list <bcm-kernel-feedback-list@xxxxxxxxxxxx> > Cc: dri-devel@xxxxxxxxxxxxxxxxxxxxx > Cc: <stable@xxxxxxxxxxxxxxx> # v5.19+ > --- > drivers/gpu/drm/vmwgfx/vmwgfx_kms.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c b/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c > index 65ed9b061753..e7bbe4b05233 100644 > --- a/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c > +++ b/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c > @@ -693,6 +693,10 @@ vmw_du_cursor_plane_prepare_fb(struct drm_plane *plane, > int ret = 0; > > if (vps->surf) { > + if (vps->surf_mapped) { > + vmw_bo_unmap(vps->surf->res.guest_memory_bo); > + vps->surf_mapped = false; > + } > vmw_surface_unreference(&vps->surf); > vps->surf = NULL; > } LGTM! Reviewed-by: Maaz Mombasawala <maaz.mombasawala@xxxxxxxxxxxx> Thanks, Maaz Mombasawala <maaz.mombasawala@xxxxxxxxxxxx>