lwn.git/drivers/gpu/drm/vmwgfx/vmwgfx_shader.c, branch docs-fixes

Convert 'alloc_obj' family to use the new default GFP_KERNEL argument

2026-02-22T01:09:51+00:00

This was done entirely with mindless brute force, using git grep -l '\

treewide: Replace kmalloc with kmalloc_obj for non-scalar types

2026-02-21T09:02:28+00:00

This is the result of running the Coccinelle script from scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to avoid scalar types (which need careful case-by-case checking), and instead replace kmalloc-family calls that allocate struct or union object instances: Single allocations: kmalloc(sizeof(TYPE), ...) are replaced with: kmalloc_obj(TYPE, ...) Array allocations: kmalloc_array(COUNT, sizeof(TYPE), ...) are replaced with: kmalloc_objs(TYPE, COUNT, ...) Flex array allocations: kmalloc(struct_size(PTR, FAM, COUNT), ...) are replaced with: kmalloc_flex(*PTR, FAM, COUNT, ...) (where TYPE may also be *VAR) The resulting allocations no longer return "void *", instead returning "TYPE *". Signed-off-by: Kees Cook

drm/vmwgfx: Fix an error return check in vmw_compat_shader_add()

2026-01-07T16:58:31+00:00

In vmw_compat_shader_add(), the return value check of vmw_shader_alloc() is not proper. Modify the check for the return pointer 'res'. Found by code review and compiled on ubuntu 20.04. Fixes: 18e4a4669c50 ("drm/vmwgfx: Fix compat shader namespace") Cc: stable@vger.kernel.org Signed-off-by: Haoxiang Li Signed-off-by: Zack Rusin Link: https://patch.msgid.link/20251224091105.1569464-1-lihaoxiang@isrc.iscas.ac.cn

drm/vmwgfx: Fix Host-Backed userspace on Guest-Backed kernel

2025-06-18T02:54:16+00:00

Running 3D applications with SVGA_FORCE_HOST_BACKED=1 or using an ancient version of mesa was broken because the buffer was pinned in VMW_BO_DOMAIN_SYS and could not be moved to VMW_BO_DOMAIN_MOB during validation. The compat_shader buffer should not pinned. Fixes: 668b206601c5 ("drm/vmwgfx: Stop using raw ttm_buffer_object's") Signed-off-by: Ian Forbes Reviewed-by: Maaz Mombasawala Signed-off-by: Zack Rusin Link: https://lore.kernel.org/r/20250429203427.1742331-1-ian.forbes@broadcom.com

drm/vmwgfx: Add new keep_resv BO param

2025-01-14T18:01:43+00:00

Adds a new BO param that keeps the reservation locked after creation. This removes the need to re-reserve the BO after creation which is a waste of cycles. This also fixes a bug in vmw_prime_import_sg_table where the imported reservation is unlocked twice. Signed-off-by: Ian Forbes Fixes: b32233acceff ("drm/vmwgfx: Fix prime import/export") Reviewed-by: Zack Rusin Signed-off-by: Zack Rusin Link: https://patchwork.freedesktop.org/patch/msgid/20250110185335.15301-1-ian.forbes@broadcom.com

drm/vmwgfx: Keep a gem reference to user bos in surfaces

2023-10-09T19:53:30+00:00

Surfaces can be backed (i.e. stored in) memory objects (mob's) which are created and managed by the userspace as GEM buffers. Surfaces grab only a ttm reference which means that the gem object can be deleted underneath us, especially in cases where prime buffer export is used. Make sure that all userspace surfaces which are backed by gem objects hold a gem reference to make sure they're not deleted before vmw surfaces are done with them, which fixes: ------------[ cut here ]------------ refcount_t: underflow; use-after-free. WARNING: CPU: 2 PID: 2632 at lib/refcount.c:28 refcount_warn_saturate+0xfb/0x150 Modules linked in: overlay vsock_loopback vmw_vsock_virtio_transport_common vmw_vsock_vmci_transport vsock snd_ens1371 snd_ac97_codec ac97_bus snd_pcm gameport> CPU: 2 PID: 2632 Comm: vmw_ref_count Not tainted 6.5.0-rc2-vmwgfx #1 Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 11/12/2020 RIP: 0010:refcount_warn_saturate+0xfb/0x150 Code: eb 9e 0f b6 1d 8b 5b a6 01 80 fb 01 0f 87 ba e4 80 00 83 e3 01 75 89 48 c7 c7 c0 3c f9 a3 c6 05 6f 5b a6 01 01 e8 15 81 98 ff <0f> 0b e9 6f ff ff ff 0f b> RSP: 0018:ffffbdc34344bba0 EFLAGS: 00010286 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000027 RDX: ffff960475ea1548 RSI: 0000000000000001 RDI: ffff960475ea1540 RBP: ffffbdc34344bba8 R08: 0000000000000003 R09: 65646e75203a745f R10: ffffffffa5b32b20 R11: 72657466612d6573 R12: ffff96037d6a6400 R13: ffff9603484805b0 R14: 000000000000000b R15: ffff9603bed06060 FS: 00007f5fd8520c40(0000) GS:ffff960475e80000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f5fda755000 CR3: 000000010d012005 CR4: 00000000003706e0 Call Trace: ? show_regs+0x6e/0x80 ? refcount_warn_saturate+0xfb/0x150 ? __warn+0x91/0x150 ? refcount_warn_saturate+0xfb/0x150 ? report_bug+0x19d/0x1b0 ? handle_bug+0x46/0x80 ? exc_invalid_op+0x1d/0x80 ? asm_exc_invalid_op+0x1f/0x30 ? refcount_warn_saturate+0xfb/0x150 drm_gem_object_handle_put_unlocked+0xba/0x110 [drm] drm_gem_object_release_handle+0x6e/0x80 [drm] drm_gem_handle_delete+0x6a/0xc0 [drm] ? __pfx_vmw_bo_unref_ioctl+0x10/0x10 [vmwgfx] vmw_bo_unref_ioctl+0x33/0x40 [vmwgfx] drm_ioctl_kernel+0xbc/0x160 [drm] drm_ioctl+0x2d2/0x580 [drm] ? __pfx_vmw_bo_unref_ioctl+0x10/0x10 [vmwgfx] ? do_vmi_munmap+0xee/0x180 vmw_generic_ioctl+0xbd/0x180 [vmwgfx] vmw_unlocked_ioctl+0x19/0x20 [vmwgfx] __x64_sys_ioctl+0x99/0xd0 do_syscall_64+0x5d/0x90 ? syscall_exit_to_user_mode+0x2a/0x50 ? do_syscall_64+0x6d/0x90 ? handle_mm_fault+0x16e/0x2f0 ? exit_to_user_mode_prepare+0x34/0x170 ? irqentry_exit_to_user_mode+0xd/0x20 ? irqentry_exit+0x3f/0x50 ? exc_page_fault+0x8e/0x190 entry_SYSCALL_64_after_hwframe+0x6e/0xd8 RIP: 0033:0x7f5fda51aaff Code: 00 48 89 44 24 18 31 c0 48 8d 44 24 60 c7 04 24 10 00 00 00 48 89 44 24 08 48 8d 44 24 20 48 89 44 24 10 b8 10 00 00 00 0f 05 <41> 89 c0 3d 00 f0 ff ff 7> RSP: 002b:00007ffd536a4d30 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007ffd536a4de0 RCX: 00007f5fda51aaff RDX: 00007ffd536a4de0 RSI: 0000000040086442 RDI: 0000000000000003 RBP: 0000000040086442 R08: 000055fa603ada50 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000246 R12: 00007ffd536a51b8 R13: 0000000000000003 R14: 000055fa5ebb4c80 R15: 00007f5fda90f040 ---[ end trace 0000000000000000 ]--- A lot of the analyis on the bug was done by Murray McAllister and Ian Forbes. Reported-by: Murray McAllister Cc: Ian Forbes Signed-off-by: Zack Rusin Fixes: a950b989ea29 ("drm/vmwgfx: Do not drop the reference to the handle too soon") Cc: # v6.2+ Reviewed-by: Martin Krastev Link: https://patchwork.freedesktop.org/patch/msgid/20230928041355.737635-1-zack@kde.org

drm/vmwgfx: Fix possible invalid drm gem put calls

2023-08-23T17:20:04+00:00

vmw_bo_unreference sets the input buffer to null on exit, resulting in null ptr deref's on the subsequent drm gem put calls. This went unnoticed because only very old userspace would be exercising those paths but it wouldn't be hard to hit on old distros with brand new kernels. Introduce a new function that abstracts unrefing of user bo's to make the code cleaner and more explicit. Signed-off-by: Zack Rusin Reported-by: Ian Forbes Fixes: 9ef8d83e8e25 ("drm/vmwgfx: Do not drop the reference to the handle too soon") Cc: # v6.4+ Reviewed-by: Maaz Mombasawala Link: https://patchwork.freedesktop.org/patch/msgid/20230818041301.407636-1-zack@kde.org

drm/vmwgfx: Do not drop the reference to the handle too soon

2023-02-15T03:06:19+00:00

v3: Fix vmw_user_bo_lookup which was also dropping the gem reference before the kernel was done with buffer depending on userspace doing the right thing. Same bug, different spot. It is possible for userspace to predict the next buffer handle and to destroy the buffer while it's still used by the kernel. Delay dropping the internal reference on the buffers until kernel is done with them. Instead of immediately dropping the gem reference in vmw_user_bo_lookup and vmw_gem_object_create_with_handle let the callers decide when they're ready give the control back to userspace. Also fixes the second usage of vmw_gem_object_create_with_handle in vmwgfx_surface.c which wasn't grabbing an explicit reference to the gem object which could have been destroyed by the userspace on the owning surface at any point. Signed-off-by: Zack Rusin Fixes: 8afa13a0583f ("drm/vmwgfx: Implement DRIVER_GEM") Reviewed-by: Martin Krastev Reviewed-by: Maaz Mombasawala Link: https://patchwork.freedesktop.org/patch/msgid/20230211050514.2431155-1-zack@kde.org

drm/vmwgfx: Stop using raw ttm_buffer_object's

2023-02-14T03:37:55+00:00

Various bits of the driver used raw ttm_buffer_object instead of the driver specific vmw_bo object. All those places used to duplicate the mapped bo caching policy of vmw_bo. Instead of duplicating all of that code and special casing various functions to work both with vmw_bo and raw ttm_buffer_object's unify the buffer object handling code. As part of that work fix the naming of bo's, e.g. insted of generic backup use 'guest_memory' because that's what it really is. All of it makes the driver easier to maintain and the code easier to read. Saves 100+ loc as well. Signed-off-by: Zack Rusin Reviewed-by: Martin Krastev Reviewed-by: Maaz Mombasawala Acked-by: Thomas Zimmermann Link: https://patchwork.freedesktop.org/patch/msgid/20230131033542.953249-9-zack@kde.org

drm/vmwgfx: Abstract placement selection

2023-02-14T03:37:55+00:00

Problem with explicit placement selection in vmwgfx is that by the time the buffer object needs to be validated the information about which placement was supposed to be used is lost. To workaround this the driver had a bunch of state in various places e.g. as_mob or cpu_blit to somehow convey the information on which placement was intended. Fix it properly by allowing the buffer objects to hold their preferred placement so it can be reused whenever needed. This makes the entire validation pipeline a lot easier both to understand and maintain. Signed-off-by: Zack Rusin Reviewed-by: Martin Krastev Reviewed-by: Maaz Mombasawala Acked-by: Thomas Zimmermann Link: https://patchwork.freedesktop.org/patch/msgid/20230131033542.953249-8-zack@kde.org