kernel.git/drivers/video/fbdev/core, branch linux-5.18.y

fbcon: Fix accelerated fbdev scrolling while logo is still shown

2022-08-17T12:40:08Z

commit 3866cba87dcd0162fb41e9b3b653d0af68fad5ec upstream. There is no need to directly skip over to the SCROLL_REDRAW case while the logo is still shown. When using DRM, this change has no effect because the code will reach the SCROLL_REDRAW case immediately anyway. But if you run an accelerated fbdev driver and have FRAMEBUFFER_CONSOLE_LEGACY_ACCELERATION enabled, console scrolling is slowed down by factors so that it feels as if you use a 9600 baud terminal. So, drop those unnecessary checks and speed up fbdev console acceleration during bootup. Cc: stable@vger.kernel.org # v5.10+ Acked-by: Daniel Vetter Signed-off-by: Helge Deller Link: https://patchwork.freedesktop.org/patch/msgid/YpkYxk7wsBPx3po+@p100 Signed-off-by: Greg Kroah-Hartman

fbcon: Fix boundary checks for fbcon=vc:n1-n2 parameters

2022-08-17T12:40:08Z

commit cad564ca557f8d3bb3b1fa965d9a2b3f6490ec69 upstream. The user may use the fbcon=vc:- option to tell fbcon to take over the given range (n1...n2) of consoles. The value for n1 and n2 needs to be a positive number and up to (MAX_NR_CONSOLES - 1). The given values were not fully checked against those boundaries yet. To fix the issue, convert first_fb_vc and last_fb_vc to unsigned integers and check them against the upper boundary, and make sure that first_fb_vc is smaller than last_fb_vc. Cc: stable@vger.kernel.org # v4.19+ Reviewed-by: Daniel Vetter Signed-off-by: Helge Deller Link: https://patchwork.freedesktop.org/patch/msgid/YpkYRMojilrtZIgM@p100 Signed-off-by: Greg Kroah-Hartman

fbdev: Disable sysfb device registration when removing conflicting FBs

2022-07-22T08:21:48Z

[ Upstream commit ee7a69aa38d87a3bbced7b8245c732c05ed0c6ec ] The platform devices registered by sysfb match with firmware-based DRM or fbdev drivers, that are used to have early graphics using a framebuffer provided by the system firmware. DRM or fbdev drivers later are probed and remove conflicting framebuffers, leading to these platform devices for generic drivers to be unregistered. But the current solution has a race, since the sysfb_init() function could be called after a DRM or fbdev driver is probed and request to unregister the devices for drivers with conflicting framebuffes. To prevent this, disable any future sysfb platform device registration by calling sysfb_disable(), if a driver requests to remove the conflicting framebuffers. Suggested-by: Daniel Vetter Signed-off-by: Javier Martinez Canillas Reviewed-by: Daniel Vetter Link: https://patchwork.freedesktop.org/patch/msgid/20220607182338.344270-4-javierm@redhat.com Signed-off-by: Sasha Levin

fbcon: Prevent that screen size is smaller than font size

2022-07-12T14:42:16Z

commit e64242caef18b4a5840b0e7a9bff37abd4f4f933 upstream. We need to prevent that users configure a screen size which is smaller than the currently selected font size. Otherwise rendering chars on the screen will access memory outside the graphics memory region. This patch adds a new function fbcon_modechange_possible() which implements this check and which later may be extended with other checks if necessary. The new function is called from the FBIOPUT_VSCREENINFO ioctl handler in fbmem.c, which will return -EINVAL if userspace asked for a too small screen size. Signed-off-by: Helge Deller Reviewed-by: Geert Uytterhoeven Cc: stable@vger.kernel.org # v5.4+ Signed-off-by: Greg Kroah-Hartman

fbcon: Disallow setting font bigger than screen size

2022-07-12T14:42:16Z

commit 65a01e601dbba8b7a51a2677811f70f783766682 upstream. Prevent that users set a font size which is bigger than the physical screen. It's unlikely this may happen (because screens are usually much larger than the fonts and each font char is limited to 32x32 pixels), but it may happen on smaller screens/LCD displays. Signed-off-by: Helge Deller Reviewed-by: Daniel Vetter Reviewed-by: Geert Uytterhoeven Cc: stable@vger.kernel.org # v4.14+ Signed-off-by: Greg Kroah-Hartman

fbmem: Check virtual screen sizes in fb_set_var()

2022-07-12T14:42:16Z

commit 6c11df58fd1ac0aefcb3b227f72769272b939e56 upstream. Verify that the fbdev or drm driver correctly adjusted the virtual screen sizes. On failure report the failing driver and reject the screen size change. Signed-off-by: Helge Deller Reviewed-by: Geert Uytterhoeven Cc: stable@vger.kernel.org # v5.4+ Signed-off-by: Greg Kroah-Hartman

fbdev: fbmem: Fix logo center image dx issue

2022-07-12T14:42:16Z

commit 955f04766d4e6eb94bf3baa539e096808c74ebfb upstream. Image.dx gets wrong value because of missing '()'. If xres == logo->width and n == 1, image.dx = -16. Signed-off-by: Guiling Deng Fixes: 3d8b1933eb1c ("fbdev: fbmem: add config option to center the bootup logo") Cc: stable@vger.kernel.org # v5.0+ Signed-off-by: Helge Deller Signed-off-by: Greg Kroah-Hartman

fbdev: defio: fix the pagelist corruption

2022-06-09T08:29:53Z

[ Upstream commit 856082f021a28221db2c32bd0531614a8382be67 ] Easily hit the below list corruption: == list_add corruption. prev->next should be next (ffffffffc0ceb090), but was ffffec604507edc8. (prev=ffffec604507edc8). WARNING: CPU: 65 PID: 3959 at lib/list_debug.c:26 __list_add_valid+0x53/0x80 CPU: 65 PID: 3959 Comm: fbdev Tainted: G U RIP: 0010:__list_add_valid+0x53/0x80 Call Trace: fb_deferred_io_mkwrite+0xea/0x150 do_page_mkwrite+0x57/0xc0 do_wp_page+0x278/0x2f0 __handle_mm_fault+0xdc2/0x1590 handle_mm_fault+0xdd/0x2c0 do_user_addr_fault+0x1d3/0x650 exc_page_fault+0x77/0x180 ? asm_exc_page_fault+0x8/0x30 asm_exc_page_fault+0x1e/0x30 RIP: 0033:0x7fd98fc8fad1 == Figure out the race happens when one process is adding &page->lru into the pagelist tail in fb_deferred_io_mkwrite(), another process is re-initializing the same &page->lru in fb_deferred_io_fault(), which is not protected by the lock. This fix is to init all the page lists one time during initialization, it not only fixes the list corruption, but also avoids INIT_LIST_HEAD() redundantly. V2: change "int i" to "unsigned int i" (Geert Uytterhoeven) Signed-off-by: Chuansheng Liu Fixes: 105a940416fc ("fbdev/defio: Early-out if page is already enlisted") Cc: Thomas Zimmermann Cc: Geert Uytterhoeven Reviewed-by: Javier Martinez Canillas Reviewed-by: Thomas Zimmermann Signed-off-by: Thomas Zimmermann Link: https://patchwork.freedesktop.org/patch/msgid/20220318005003.51810-1-chuansheng.liu@intel.com Signed-off-by: Sasha Levin

fbcon: Consistently protect deferred_takeover with console_lock()

2022-06-09T08:29:33Z

[ Upstream commit 43553559121ca90965b572cf8a1d6d0fd618b449 ] This shouldn't be a problem in practice since until we've actually taken over the console there's nothing we've registered with the console/vt subsystem, so the exit/unbind path that check this can't do the wrong thing. But it's confusing, so fix it by moving it a tad later. Acked-by: Sam Ravnborg Signed-off-by: Daniel Vetter Cc: Daniel Vetter Cc: Du Cheng Cc: Tetsuo Handa Cc: Claudio Suarez Cc: Thomas Zimmermann Link: https://patchwork.freedesktop.org/patch/msgid/20220405210335.3434130-14-daniel.vetter@ffwll.ch Signed-off-by: Sasha Levin

fbdev: Prevent possible use-after-free in fb_release()

2022-05-06T07:21:20Z

Most fbdev drivers have issues with the fb_info lifetime, because call to framebuffer_release() from their driver's .remove callback, rather than doing from fbops.fb_destroy callback. Doing that will destroy the fb_info too early, while references to it may still exist, leading to a use-after-free error. To prevent this, check the fb_info reference counter when attempting to kfree the data structure in framebuffer_release(). That will leak it but at least will prevent the mentioned error. Signed-off-by: Daniel Vetter Signed-off-by: Javier Martinez Canillas Reviewed-by: Thomas Zimmermann Link: https://patchwork.freedesktop.org/patch/msgid/20220505220413.365977-1-javierm@redhat.com