If, for any reason, the open-coded arithmetic causes a wraparound, the
protection that `struct_size()` adds against potential integer overflows
is defeated. Fix this by hardening call to `struct_size()` with `size_add()`.
Fixes: 40e1a70b4aed ("drm: Add GUD USB Display driver")
Signed-off-by: "Gustavo A. R. Silva" <gustavoars@kernel.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/ZQSlyHKPdw/zsy4c@work
Signed-off-by: Kees Cook <keescook@chromium.org>
Use vmalloc_array and vcalloc to protect against
multiplication overflows.
The changes were done using the following Coccinelle
semantic patch:
// <smpl>
@initialize:ocaml@
@@
let rename alloc =
match alloc with
"vmalloc" -> "vmalloc_array"
| "vzalloc" -> "vcalloc"
| _ -> failwith "unknown"
@@
size_t e1,e2;
constant C1, C2;
expression E1, E2, COUNT, x1, x2, x3;
typedef u8;
typedef __u8;
type t = {u8,__u8,char,unsigned char};
identifier alloc = {vmalloc,vzalloc};
fresh identifier realloc = script:ocaml(alloc) { rename alloc };
@@
(
alloc(x1*x2*x3)
|
alloc(C1 * C2)
|
alloc((sizeof(t)) * (COUNT), ...)
|
- alloc((e1) * (e2))
+ realloc(e1, e2)
|
- alloc((e1) * (COUNT))
+ realloc(COUNT, e1)
|
- alloc((E1) * (E2))
+ realloc(E1, E2)
)
// </smpl>
Signed-off-by: Julia Lawall <Julia.Lawall@inria.fr>
Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Noralf Trønnes <noralf@tronnes.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20230627144339.144478-4-Julia.Lawall@inria.fr
Replace the use of drm_debugfs_create_files() with the new drm_debugfs_add_file() function, which center the debugfs files management on the drm_device instead of drm_minor. Moreover, remove the debugfs_init hook and add the debugfs files directly on gud_probe(), before drm_dev_register(). Signed-off-by: Maíra Canal <mcanal@igalia.com> Acked-by: Noralf Trønnes <noralf@tronnes.org> Signed-off-by: Maíra Canal <mairacanal@riseup.net> Link: https://patchwork.freedesktop.org/patch/msgid/20221226155029.244355-3-mcanal@igalia.com
Add missing vmalloc.h include.
Fixes: c17d048609bf ("drm/gud: Use the shadow plane helper")
Reported-by: kernel test robot <lkp@intel.com>
Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Noralf Trønnes <noralf@tronnes.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20221207-gud-missing-include-v1-0-c5b32c9c59da@tronnes.org
gud has a module parameter that controls whether framebuffer flushing happens synchronously during the commit or asynchronously in a worker. GNOME before version 3.38 handled all displays in the same rendering loop. This lead to gud slowing down the refresh rate for a faster monitor. This has now been fixed so lets change the default. The plan is to remove async flushing in the future. The code is now structured in a way that makes it easy to do this. Link: https://blogs.gnome.org/shell-dev/2020/07/02/splitting-up-the-frame-clock/ Suggested-by: Thomas Zimmermann <tzimmermann@suse.de> Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de> Signed-off-by: Noralf Trønnes <noralf@tronnes.org> Link: https://patchwork.freedesktop.org/patch/msgid/20221122-gud-shadow-plane-v2-6-435037990a83@tronnes.org
Use the shadow plane helper to take care of mapping the framebuffer for CPU access. The synchronous flushing is now done inline without the use of a worker. The async path now uses a shadow buffer to hold framebuffer changes and it doesn't read the framebuffer behind userspace's back anymore. v2: - Use src as variable name for iosys_map (Thomas) - Prepare imported buffer for CPU access in the driver (Thomas) Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de> Signed-off-by: Noralf Trønnes <noralf@tronnes.org> Link: https://patchwork.freedesktop.org/patch/msgid/20221122-gud-shadow-plane-v2-5-435037990a83@tronnes.org
In preparation for moving to the shadow plane helper prepare the framebuffer for CPU access as early as possible. v2: - Use src as variable name for iosys_map (Thomas) Reviewed-by: Javier Martinez Canillas <javierm@redhat.com> Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de> Signed-off-by: Noralf Trønnes <noralf@tronnes.org> Link: https://patchwork.freedesktop.org/patch/msgid/20221122-gud-shadow-plane-v2-4-435037990a83@tronnes.org
In preparation for inlining synchronous flushing split out the part of gud_flush_work() that can be shared by the sync and async code paths. Reviewed-by: Javier Martinez Canillas <javierm@redhat.com> Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de> Signed-off-by: Noralf Trønnes <noralf@tronnes.org> Link: https://patchwork.freedesktop.org/patch/msgid/20221122-gud-shadow-plane-v2-3-435037990a83@tronnes.org
If a framebuffer flush fails the driver will do one retry by requeing the worker. Currently the worker is used even for synchronous flushing, but a later patch will inline it, so this needs to change. Thinking about how to solve this I came to the conclusion that this retry mechanism was a fix for a problem that was only in the mind of the developer (me) and not something that solved a real problem. So let's remove this for now and revisit later should it become necessary. gud_add_damage() has now only one caller so it can be inlined. Reviewed-by: Javier Martinez Canillas <javierm@redhat.com> Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de> Signed-off-by: Noralf Trønnes <noralf@tronnes.org> Link: https://patchwork.freedesktop.org/patch/msgid/20221122-gud-shadow-plane-v2-2-435037990a83@tronnes.org
UBSAN complains about invalid value for bool:
[ 101.165172] [drm] Initialized gud 1.0.0 20200422 for 2-3.2:1.0 on minor 1
[ 101.213360] gud 2-3.2:1.0: [drm] fb1: guddrmfb frame buffer device
[ 101.213426] usbcore: registered new interface driver gud
[ 101.989431] ================================================================================
[ 101.989441] UBSAN: invalid-load in linux/include/linux/iosys-map.h:253:9
[ 101.989447] load of value 121 is not a valid value for type '_Bool'
[ 101.989451] CPU: 1 PID: 455 Comm: kworker/1:6 Not tainted 5.18.0-rc5-gud-5.18-rc5 #3
[ 101.989456] Hardware name: Hewlett-Packard HP EliteBook 820 G1/1991, BIOS L71 Ver. 01.44 04/12/2018
[ 101.989459] Workqueue: events_long gud_flush_work [gud]
[ 101.989471] Call Trace:
[ 101.989474] <TASK>
[ 101.989479] dump_stack_lvl+0x49/0x5f
[ 101.989488] dump_stack+0x10/0x12
[ 101.989493] ubsan_epilogue+0x9/0x3b
[ 101.989498] __ubsan_handle_load_invalid_value.cold+0x44/0x49
[ 101.989504] dma_buf_vmap.cold+0x38/0x3d
[ 101.989511] ? find_busiest_group+0x48/0x300
[ 101.989520] drm_gem_shmem_vmap+0x76/0x1b0 [drm_shmem_helper]
[ 101.989528] drm_gem_shmem_object_vmap+0x9/0xb [drm_shmem_helper]
[ 101.989535] drm_gem_vmap+0x26/0x60 [drm]
[ 101.989594] drm_gem_fb_vmap+0x47/0x150 [drm_kms_helper]
[ 101.989630] gud_prep_flush+0xc1/0x710 [gud]
[ 101.989639] ? _raw_spin_lock+0x17/0x40
[ 101.989648] gud_flush_work+0x1e0/0x430 [gud]
[ 101.989653] ? __switch_to+0x11d/0x470
[ 101.989664] process_one_work+0x21f/0x3f0
[ 101.989673] worker_thread+0x200/0x3e0
[ 101.989679] ? rescuer_thread+0x390/0x390
[ 101.989684] kthread+0xfd/0x130
[ 101.989690] ? kthread_complete_and_exit+0x20/0x20
[ 101.989696] ret_from_fork+0x22/0x30
[ 101.989706] </TASK>
[ 101.989708] ================================================================================
The source of this warning is in iosys_map_clear() called from
dma_buf_vmap(). It conditionally sets values based on map->is_iomem. The
iosys_map variables are allocated uninitialized on the stack leading to
->is_iomem having all kinds of values and not only 0/1.
Fix this by zeroing the iosys_map variables.
Fixes: 40e1a70b4aed ("drm: Add GUD USB Display driver")
Cc: <stable@vger.kernel.org> # v5.18+
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Noralf Trønnes <noralf@tronnes.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20221122-gud-shadow-plane-v2-1-435037990a83@tronnes.org