aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/video/fbdev/core/fbcmap.c (follow)
AgeCommit message (Collapse)AuthorFilesLines
2019-06-12fbdev: lock_fb_info cannot failDaniel Vetter1-5/+1
Ever since commit c47747fde931c02455683bd00ea43eaa62f35b0e Author: Linus Torvalds <torvalds@linux-foundation.org> Date: Wed May 11 14:58:34 2011 -0700 fbmem: make read/write/ioctl use the frame buffer at open time fbdev has gained proper refcounting for the fbinfo attached to any open files, which means that the backing driver (stored in fb_info->fbops) cannot untimely disappear anymore. The only thing that can happen is that the entire device just outright disappears and gets unregistered, but file_fb_info does check for that. Except that it's racy - it only checks once at the start of a file_ops, there's no guarantee that the underlying fbdev won't untimely disappear. Aside: A proper way to fix that race is probably to replicate the srcu trickery we've rolled out in drm. But given that this race has existed since forever it's probably not one we need to fix right away. do_unregister_framebuffer also nowhere clears fb_info->fbops, hence the check in lock_fb_info can't possible catch a disappearing fbdev later on. Long story short: Ever since the above commit the fb_info->fbops checks have essentially become dead code. Remove this all. Aside from the file_ops callbacks, and stuff called from there there's only register/unregister code left. If that goes wrong a driver managed to register/unregister a device instance twice or in the wrong order. That's just a driver bug. v2: - fb_mmap had an open-coded version of the fbinfo->fops check, because it doesn't need the fbinfo->lock. Delete that too. - Use the wrapper function in fb_open/release now, since no difference anymore. Signed-off-by: Daniel Vetter <daniel.vetter@intel.com> Reviewed-by: Sam Ravnborg <sam@ravnborg.org> Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com> Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: Hans de Goede <hdegoede@redhat.com> Cc: Yisheng Xie <ysxie@foxmail.com> Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: "Noralf Trønnes" <noralf@tronnes.org> Cc: Peter Rosin <peda@axentia.se> Cc: "Michał Mirosław" <mirq-linux@rere.qmqm.pl> Cc: Mikulas Patocka <mpatocka@redhat.com> Cc: "Gustavo A. R. Silva" <gustavo@embeddedor.com> Cc: linux-fbdev@vger.kernel.org Link: https://patchwork.freedesktop.org/patch/msgid/20190528090304.9388-17-daniel.vetter@ffwll.ch
2019-04-11fbdev: fix WARNING in __alloc_pages_nodemask bugJiufei Xue1-0/+2
Syzkaller hit 'WARNING in __alloc_pages_nodemask' bug. WARNING: CPU: 1 PID: 1473 at mm/page_alloc.c:4377 __alloc_pages_nodemask+0x4da/0x2130 Kernel panic - not syncing: panic_on_warn set ... Call Trace: alloc_pages_current+0xb1/0x1e0 kmalloc_order+0x1f/0x60 kmalloc_order_trace+0x1d/0x120 fb_alloc_cmap_gfp+0x85/0x2b0 fb_set_user_cmap+0xff/0x370 do_fb_ioctl+0x949/0xa20 fb_ioctl+0xdd/0x120 do_vfs_ioctl+0x186/0x1070 ksys_ioctl+0x89/0xa0 __x64_sys_ioctl+0x74/0xb0 do_syscall_64+0xc8/0x550 entry_SYSCALL_64_after_hwframe+0x49/0xbe This is a warning about order >= MAX_ORDER and the order is from userspace ioctl. Add flag __NOWARN to silence this warning. Signed-off-by: Jiufei Xue <jiufei.xue@linux.alibaba.com> Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
2017-01-24fbdev: color map copying bounds checkingKees Cook1-12/+14
Copying color maps to userspace doesn't check the value of to->start, which will cause kernel heap buffer OOB read due to signedness wraps. CVE-2016-8405 Link: http://lkml.kernel.org/r/20170105224249.GA50925@beast Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Kees Cook <keescook@chromium.org> Reported-by: Peter Pi (@heisecode) of Trend Micro Cc: Min Chong <mchong@google.com> Cc: Dan Carpenter <dan.carpenter@oracle.com> Cc: Tomi Valkeinen <tomi.valkeinen@ti.com> Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-17fbdev: move fbdev core files to separate directoryTomi Valkeinen1-0/+362
Instead of having fbdev framework core files at the root fbdev directory, mixed with random fbdev device drivers, move the fbdev core files to a separate core directory. This makes it much clearer which of the files are actually part of the fbdev framework, and which are part of device drivers. Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com> Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> Acked-by: Rob Clark <robdclark@gmail.com> Acked-by: Jingoo Han <jg1.han@samsung.com> Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>