kernel/linux.git/drivers/video/console, branch v5.15.7

vgacon: Propagate console boot parameters before calling `vc_resize'

2021-12-08T08:04:55+00:00

commit 3dfac26e2ef29ff2abc2a75aa4cd48fce25a2c4b upstream. Fix a division by zero in `vgacon_resize' with a backtrace like: vgacon_resize vc_do_resize vgacon_init do_bind_con_driver do_unbind_con_driver fbcon_fb_unbind do_unregister_framebuffer do_register_framebuffer register_framebuffer __drm_fb_helper_initial_config_and_unlock drm_helper_hpd_irq_event dw_hdmi_irq irq_thread kthread caused by `c->vc_cell_height' not having been initialized. This has only started to trigger with commit 860dafa90259 ("vt: Fix character height handling with VT_RESIZEX"), however the ultimate offender is commit 50ec42edd978 ("[PATCH] Detaching fbcon: fix vgacon to allow retaking of the console"). Said commit has added a call to `vc_resize' whenever `vgacon_init' is called with the `init' argument set to 0, which did not happen before. And the call is made before a key vgacon boot parameter retrieved in `vgacon_startup' has been propagated in `vgacon_init' for `vc_resize' to use to the console structure being worked on. Previously the parameter was `c->vc_font.height' and now it is `c->vc_cell_height'. In this particular scenario the registration of fbcon has failed and vt resorts to vgacon. Now fbcon does have initialized `c->vc_font.height' somehow, unlike `c->vc_cell_height', which is why this code did not crash before, but either way the boot parameters should have been copied to the console structure ahead of the call to `vc_resize' rather than afterwards, so that first the call has a chance to use them and second they do not change the console structure to something possibly different from what was used by `vc_resize'. Move the propagation of the vgacon boot parameters ahead of the call to `vc_resize' then. Adjust the comment accordingly. Fixes: 50ec42edd978 ("[PATCH] Detaching fbcon: fix vgacon to allow retaking of the console") Cc: stable@vger.kernel.org # v2.6.18+ Reported-by: Wim Osterholt Reported-by: Pavel V. Panteleev Signed-off-by: Maciej W. Rozycki Link: https://lore.kernel.org/r/alpine.DEB.2.21.2110252317110.58149@angie.orcam.me.uk Signed-off-by: Greg Kroah-Hartman

parisc/sticon: fix reverse colors

2021-11-25T08:48:46+00:00

commit bec05f33ebc1006899c6d3e59a00c58881fe7626 upstream. sticon_build_attr() checked the reverse argument and flipped background and foreground color, but returned the non-reverse value afterwards. Fix this and also add two local variables for foreground and background color to make the code easier to read. Signed-off-by: Sven Schnelle Cc: Signed-off-by: Helge Deller Signed-off-by: Greg Kroah-Hartman

um: allow disabling NO_IOMEM

2021-06-17T19:44:50+00:00

Adjust the kconfig a little to allow disabling NO_IOMEM in UML. To make an "allyesconfig" with CONFIG_NO_IOMEM=n build, adjust a few Kconfig things elsewhere and add dummy asm/fb.h and asm/vga.h files. Signed-off-by: Johannes Berg Signed-off-by: Richard Weinberger

Merge branch 'resizex' (patches from Maciej)

2021-05-13T18:12:51+00:00

Merge VT_RESIZEX fixes from Maciej Rozycki: "I got to the bottom of the issue with VT_RESIZEX recently discussed and came up with this small patch series, fixing an additional issue that I originally thought might be broken VGA hardware emulation with my laptop, which however turned out to be intertwined with the original problem and also a regression introduced somewhat later. The fix for that because the first patch, and then to make backporting feasible I had to put a revert of the offending change from last September next, followed by a proper fix for the framebuffer issue that change had tried to address. See individual change descriptions for details. These have been verified with true VGA hardware (a Trident TVGA8900 ISA video adapter) using various combinations of `svgatextmode' and `setfont' command invocations to change both the VT size and the font size, and also switching between the text console and X11, both by starting/stopping the X server and by switching between VTs. All this to ensure bringing the behaviour of VGA text console back to correct operation as it used to be with Linux 2.6.18" * emailed patches from Maciej W. Rozycki : vt: Fix character height handling with VT_RESIZEX vt_ioctl: Revert VT_RESIZEX parameter handling removal vgacon: Record video mode changes with VT_RESIZEX

vt: Fix character height handling with VT_RESIZEX

2021-05-13T18:00:18+00:00

Restore the original intent of the VT_RESIZEX ioctl's `v_clin' parameter which is the number of pixel rows per character (cell) rather than the height of the font used. For framebuffer devices the two values are always the same, because the former is inferred from the latter one. For VGA used as a true text mode device these two parameters are independent from each other: the number of pixel rows per character is set in the CRT controller, while font height is in fact hardwired to 32 pixel rows and fonts of heights below that value are handled by padding their data with blanks when loaded to hardware for use by the character generator. One can change the setting in the CRT controller and it will update the screen contents accordingly regardless of the font loaded. The `v_clin' parameter is used by the `vgacon' driver to set the height of the character cell and then the cursor position within. Make the parameter explicit then, by defining a new `vc_cell_height' struct member of `vc_data', set it instead of `vc_font.height' from `v_clin' in the VT_RESIZEX ioctl, and then use it throughout the `vgacon' driver except where actual font data is accessed which as noted above is independent from the CRTC setting. This way the framebuffer console driver is free to ignore the `v_clin' parameter as irrelevant, as it always should have, avoiding any issues attempts to give the parameter a meaning there could have caused, such as one that has led to commit 988d0763361b ("vt_ioctl: make VT_RESIZEX behave like VT_RESIZE"): "syzbot is reporting UAF/OOB read at bit_putcs()/soft_cursor() [1][2], for vt_resizex() from ioctl(VT_RESIZEX) allows setting font height larger than actual font height calculated by con_font_set() from ioctl(PIO_FONT). Since fbcon_set_font() from con_font_set() allocates minimal amount of memory based on actual font height calculated by con_font_set(), use of vt_resizex() can cause UAF/OOB read for font data." The problem first appeared around Linux 2.5.66 which predates our repo history, but the origin could be identified with the old MIPS/Linux repo also at: as commit 9736a3546de7 ("Merge with Linux 2.5.66."), where VT_RESIZEX code in `vt_ioctl' was updated as follows: if (clin) - video_font_height = clin; + vc->vc_font.height = clin; making the parameter apply to framebuffer devices as well, perhaps due to the use of "font" in the name of the original `video_font_height' variable. Use "cell" in the new struct member then to avoid ambiguity. References: [1] https://syzkaller.appspot.com/bug?id=32577e96d88447ded2d3b76d71254fb855245837 [2] https://syzkaller.appspot.com/bug?id=6b8355d27b2b94fb5cedf4655e3a59162d9e48e3 Signed-off-by: Maciej W. Rozycki Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Cc: stable@vger.kernel.org # v2.6.12+ Signed-off-by: Linus Torvalds

vgacon: Record video mode changes with VT_RESIZEX

2021-05-13T18:00:18+00:00

Fix an issue with VGA console font size changes made after the initial video text mode has been changed with a user tool like `svgatextmode' calling the VT_RESIZEX ioctl. As it stands in that case the original screen geometry continues being used to validate further VT resizing. Consequently when the video adapter is firstly reprogrammed from the original say 80x25 text mode using a 9x16 character cell (720x400 pixel resolution) to say 80x37 text mode and the same character cell (720x592 pixel resolution), and secondly the CRTC character cell updated to 9x8 (by loading a suitable font with the KD_FONT_OP_SET request of the KDFONTOP ioctl), the VT geometry does not get further updated from 80x37 and only upper half of the screen is used for the VT, with the lower half showing rubbish corresponding to whatever happens to be there in the video memory that maps to that part of the screen. Of course the proportions change according to text mode geometries and font sizes chosen. Address the problem then, by updating the text mode geometry defaults rather than checking against them whenever the VT is resized via a user ioctl. Signed-off-by: Maciej W. Rozycki Fixes: e400b6ec4ede ("vt/vgacon: Check if screen resize request comes from userspace") Cc: stable@vger.kernel.org # v2.6.24+ Signed-off-by: Linus Torvalds

vgacon: drop unused vga_init_done

2021-03-23T09:26:04+00:00

Commit 973c096f6a85 ("vgacon: remove software scrollback support") removed all uses of vga_init_done, so let's get rid of it entirely. Signed-off-by: Stephen Kitt Link: https://lore.kernel.org/r/20210215170837.1599706-1-steve@sk2.org Signed-off-by: Greg Kroah-Hartman

vgacon: comment on vga_rolled_over

2021-03-10T08:34:06+00:00

Long time ago, I figured out what this number is good for and documented that locally. But never submitted, so do it now. Cc: dri-devel@lists.freedesktop.org Cc: linux-fbdev@vger.kernel.org Signed-off-by: Jiri Slaby Link: https://lore.kernel.org/r/20210302062214.29627-4-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman

vgacon: drop BROKEN_GRAPHICS_PROGRAMS

2021-01-07T15:17:31+00:00

BROKEN_GRAPHICS_PROGRAMS is defined when CONFIG_VGA_CONSOLE=y. And vgacon.c is built exclusively in that case too. So the check for BROKEN_GRAPHICS_PROGRAMS is pointless in vgacon.c as it is always true. So remove the test and BROKEN_GRAPHICS_PROGRAMS completely. This also eliminates the need for vga_font_is_default global as it is only set and never read. Cc: dri-devel@lists.freedesktop.org Cc: linux-fbdev@vger.kernel.org Signed-off-by: Jiri Slaby Link: https://lore.kernel.org/r/20210105120239.28031-9-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman

parisc/sticore: Avoid hard-coding built-in font charcount

2020-11-16T15:31:58+00:00

sti_select_fbfont() and sti_cook_fonts() are hard-coding the number of characters of our built-in fonts as 256. Recently, we included that information in our kernel font descriptor `struct font_desc`, so use `fbfont->charcount` instead of hard-coded values. Depends on patch "Fonts: Add charcount field to font_desc". Signed-off-by: Peilin Ye Reviewed-by: Daniel Vetter Reviewed-by: Greg Kroah-Hartman Signed-off-by: Daniel Vetter Link: https://patchwork.freedesktop.org/patch/msgid/037186fb50cf3d17bb7bc9482357635b9df6076e.1605169912.git.yepeilin.cs@gmail.com