Changes in font_rotate.c

13ad98eaabef611f042d49a9077be060ad03284d - Merge tag 'fbdev-for-7.1-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/linux-fbdev

Tue, 05 May 2026 23:25:44 +0200

Merge tag 'fbdev-for-7.1-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/linux-fbdevPull fbdev fixes from Helge Deller: "Four small patches for fbdev, of which two are important: One fixes the bitmap font generation and the other prevents a possible use-after-free in udlfb: - Fix rotating fonts by 180 degrees (Thomas Zimmermann) - Drop duplicate include of linux/module.h in fb_defio (Chen Ni) - Add vm_ops in udlfb to prevent use-after-free (Rajat Gupta) - ipu-v3: clean up kernel-doc warnings (Randy Dunlap)"* tag 'fbdev-for-7.1-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/linux-fbdev: fbdev: udlfb: add vm_ops to dlfb_ops_mmap to prevent use-after-free lib/fonts: Fix bit position when rotating by 180 degrees fbdev: defio: Remove duplicate include of linux/module.h fbdev: ipu-v3: clean up kernel-doc warnings List of files: /linux/lib/fonts/font_rotate.c

d237f719b2726c0e6d62bfa1543f53b624471929 - lib/fonts: Fix bit position when rotating by 180 degrees

Tue, 28 Apr 2026 10:28:43 +0200

lib/fonts: Fix bit position when rotating by 180 degreesFix the horizontal bit position when rotating a glyph by 180°. Theoriginal code in rotate_ud() rounded the value in width up to amultiple of 8, aka the bit pitch, and calculated the rotated pixelfrom that value. The new code stores the glyph's pitch in bit_pitch,but fails to update the rotated pixel's output accordingly. Simplyreplacing the variable does this.The bug can be reproduced by setting a font with an unaligned width,such as sun12x22, like this: setfont sun12x22 echo 2 > /sys/class/graphics/fbcon/rotateWithout the fix, the font looks distorted.Fixes: a30e9e6b018f ("lib/fonts: Refactor glyph-rotation helpers")Closes: https://lore.gitlab.freedesktop.org/drm-ai-reviews/review-patch7-20260407092555.58816-8-tzimmermann@suse.de/Cc: dri-devel@lists.freedesktop.orgCc: linux-fbdev@vger.kernel.orgSigned-off-by: Thomas Zimmermann Signed-off-by: Helge Deller List of files: /linux/lib/fonts/font_rotate.c

0fc8f6200d2313278fbf4539bbab74677c685531 - Merge drm/drm-fixes into drm-misc-fixes

Mon, 27 Apr 2026 10:26:49 +0200

Merge drm/drm-fixes into drm-misc-fixesGetting fixes and updates from v7.1-rc1.Signed-off-by: Thomas Zimmermann List of files: /linux/lib/fonts/font_rotate.c

afac4c66d1aa6396ce44d94fe895d7b61e085fd4 - Merge tag 'fbdev-for-7.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/linux-fbdev

Wed, 15 Apr 2026 17:37:45 +0200

Merge tag 'fbdev-for-7.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/linux-fbdevPull fbdev updates from Helge Deller: "A major refactorization by Thomas Zimmermann from SUSE regarding handling of console font data, addition of helpers for console font rotation and split into individual components for glyphs, fonts and the overall fbcon state. And there is the round of usual code cleanups and fixes: Cleanups: - atyfb: Remove unused fb_list (Geert Uytterhoeven) - goldfishfb, wmt_ge_rops: use devm_platform_ioremap_resource() (Amin GATTOUT) - matroxfb: Mark variable with __maybe_unused (Andy Shevchenko) - omapfb: Add missing error check for clk_get() (Chen Ni) - tdfxfb: Make the VGA register initialisation a bit more obvious (Daniel Palmer) - macfb: Replace deprecated strcpy with strscpy (Thorsten Blum) Fixes: - tdfxfb, udlfb: avoid divide-by-zero on FBIOPUT_VSCREENINFO (Greg Kroah-Hartman) - omap2: fix inconsistent lock returns in omapfb_mmap (Hongling Zeng) - viafb: check ioremap return value in viafb_lcd_get_mobile_state (Wang Jun)"* tag 'fbdev-for-7.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/linux-fbdev: (40 commits) fbdev: udlfb: avoid divide-by-zero on FBIOPUT_VSCREENINFO fbdev: tdfxfb: avoid divide-by-zero on FBIOPUT_VSCREENINFO fbdev: omap2: fix inconsistent lock returns in omapfb_mmap MAINTAINERS: Add dedicated entry for fbcon fbcon: Put font-rotation state into separate struct fbcon: Fill cursor mask in helper function lib/fonts: Implement font rotation lib/fonts: Refactor glyph-rotation helpers lib/fonts: Refactor glyph-pattern helpers lib/fonts: Implement glyph rotation lib/fonts: Clean up Makefile lib/fonts: Provide helpers for calculating glyph pitch and size vt: Implement helpers for struct vc_font in source file fbcon: Avoid OOB font access if console rotation fails fbdev: atyfb: Remove unused fb_list fbdev: matroxfb: Mark variable with __maybe_unused to avoid W=1 build break fbdev: update help text for CONFIG_FB_NVIDIA fbdev: omapfb: Add missing error check for clk_get() fbdev: viafb: check ioremap return value in viafb_lcd_get_mobile_state lib/fonts: Remove internal symbols and macros from public header file ... List of files: /linux/lib/fonts/font_rotate.c

cfa72955a029cd79433694cac6b5630788609cd4 - lib/fonts: Implement font rotation

Tue, 07 Apr 2026 11:23:19 +0200

lib/fonts: Implement font rotationMove the core of fbcon's font-rotation code to the font library asthe new helper font_data_rotate(). The code can rotate in steps of90°. For completeness, it also copies the glyph data for multiplesof 360°.Bring back the memset optimization. A memset to 0 again clears thewhole glyph output buffer. Then use the internal rotation helpers onthe cleared output. Fbcon's original implementation worked like this,but lost it during refactoring.Replace fbcon's font-rotation code with the new implementations.All that's left to do for fbcon is to maintain its internal fbconstate.v2:- fix typosSigned-off-by: Thomas Zimmermann Signed-off-by: Helge Deller List of files: /linux/lib/fonts/font_rotate.c

a30e9e6b018f40941a626ff77e0bf35c015038fa - lib/fonts: Refactor glyph-rotation helpers

Tue, 07 Apr 2026 11:23:18 +0200

lib/fonts: Refactor glyph-rotation helpersChange the signatures of the glyph-rotation helpers to match theirpublic interfaces. Drop the inline qualifier.Rename several variables to better match their meaning. Especiallyrename variables to bit_pitch (or a variant thereof) if they storea pitch value in bits per scanline. The original code is fairlyconfusing about this. Move the calculation of the bit pitch into thenew helper font_glyph_bit_pitch().Signed-off-by: Thomas Zimmermann Signed-off-by: Helge Deller List of files: /linux/lib/fonts/font_rotate.c

6ad4ed8408157b1c78f69995c5808d9460fba58d - lib/fonts: Refactor glyph-pattern helpers

Tue, 07 Apr 2026 11:23:17 +0200

lib/fonts: Refactor glyph-pattern helpersChange the signatures of the pattern helpers to align them with otherfont-glyph helpers: use the font_glyph_ prefix and pass the glyphbuffer first.Calculating the position of the involved bit is somewhat obfuscatedin the original implementation. Move it into the new helper__font_glyph_pos() and use the result as array index and bit position.Note that these bit helpers use a bit pitch, while other code uses abyte pitch. This is intentional and required here.v2:- fix typos in commit messageSigned-off-by: Thomas Zimmermann Signed-off-by: Helge Deller List of files: /linux/lib/fonts/font_rotate.c

bdfd943231347ce57133d1ba2d93ed87f1050e81 - lib/fonts: Implement glyph rotation

Tue, 07 Apr 2026 11:23:16 +0200

lib/fonts: Implement glyph rotationMove the glyph rotation helpers from fbcon to the font library. Wrap thembehind clean interfaces. Also clear the output memory to zero. Previously,the implementation relied on the caller to do that.Go through the fbcon code and callers of the glyph-rotation helpers. Inaddition to the font rotation, there's also the cursor code, which usesthe rotation helpers.The font-rotation relied on a single memset to zero for the whole font.This is now multiple memsets on each glyph. This will be sorted out whenthe font library also implements font rotation.Building glyph rotation in the font library still depends onCONFIG_FRAMEBUFFER_CONSOLE_ROTATION=y. If we get more users of the code,we can still add a dedicated Kconfig symbol to the font library.No changes have been made to the actual implementation of the rotate_*()and pattern_*() functions. These will be refactored as separate changes.v2:- fix typosSigned-off-by: Thomas Zimmermann Signed-off-by: Helge Deller List of files: /linux/lib/fonts/font_rotate.c