kernel/linux.git/include/linux/vt_kern.h, branch v6.6.132

kernel/panic: Drop unblank_screen call

2022-09-01T14:55:35+00:00

console_unblank() does this too (called in both places right after), and with a lot more confidence inspiring approach to locking. Reconstructing this story is very strange: In b61312d353da ("oops handling: ensure that any oops is flushed to the mtdoops console") it is claimed that a printk(" "); flushed out the console buffer, which was removed in e3e8a75d2acf ("[PATCH] Extract and use wake_up_klogd()"). In todays kernels this is done way earlier in console_flush_on_panic with some really nasty tricks. I didn't bother to fully reconstruct this all, least because the call to bust_spinlock(0); gets moved every few years, depending upon how the wind blows (or well, who screamed loudest about the various issue each call site caused). Before that commit the only calls to console_unblank() where in s390 arch code. The other side here is the console->unblank callback, which was introduced in 2.1.31 for the vt driver. Which predates the console_unblank() function by a lot, which was added (without users) in 2.4.14.3. So pretty much impossible to guess at any motivation here. Also afaict the vt driver is the only (and always was the only) console driver implementing the unblank callback, so no idea why a call to console_unblank() was added for the mtdooops driver - the action actually flushing out the console buffers is done from console_unlock() only. Note that as prep for the s390 users the locking was adjusted in 2.5.22 (I couldn't figure out how to properly reference the BK commit from the historical git trees) from a normal semaphore to a trylock. Note that a copy of the direct unblank_screen() call was added to panic() in c7c3f05e341a ("panic: avoid deadlocks in re-entrant console drivers"), which partially inlined the bust_spinlocks(0); call. Long story short, I have no idea why the direct call to unblank_screen survived for so long (the infrastructure to do it properly existed for years), nor why it wasn't removed when the console_unblank() call was finally added. But it makes a ton more sense to finally do that than not - it's just better encapsulation to go through the console functions instead of doing a direct call, so let's dare. Plus it really does not make much sense to call the only unblank implementation there is twice, once without, and once with appropriate locking. Cc: Greg Kroah-Hartman Cc: Jiri Slaby Cc: Daniel Vetter Cc: "Ilpo Järvinen" Cc: Tetsuo Handa Cc: Xuezhi Zhang Cc: Yangxi Xiang Cc: nick black Cc: Petr Mladek Cc: Andrew Morton Cc: Luis Chamberlain Cc: "Guilherme G. Piccoli" Cc: Marco Elver Cc: John Ogness Cc: Sebastian Andrzej Siewior Cc: David Gow Cc: tangmeng Cc: Tiezhu Yang Cc: Chris Wilson Reviewed-by: Petr Mladek Acked-by: Sebastian Andrzej Siewior Signed-off-by: Daniel Vetter Signed-off-by: Andrew Morton Link: https://lore.kernel.org/r/20220830145004.430545-1-daniel.vetter@ffwll.ch Signed-off-by: Greg Kroah-Hartman

vt: keyboard.c: make console an unsigned int

2021-07-27T10:23:20+00:00

The console variable is used everywhere in some fun pointer path and array indexes and for some reason isn't always declared as unsigned. This plays havoc with some static analysis tools so mark the variable as unsigned so we "know" we can not wrap the arrays backwards here. Cc: Jiri Slaby Cc: Andy Shevchenko Reported-by: Jordy Zomer Link: https://lore.kernel.org/r/20210726134322.2274919-2-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman

vt: vt_kern.h, remove the repeated declaration

2021-06-09T12:44:31+00:00

Function 'vt_set_led_state' is declared twice, so remove the repeated declaration. Cc: Jiri Slaby Signed-off-by: Shaokun Zhang Link: https://lore.kernel.org/r/1623062933-52943-1-git-send-email-zhangshaokun@hisilicon.com 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

vt: move vc_translate to vt.c and rename it

2020-06-24T15:08:31+00:00

vc_translate is used only in vt.c, so move the definition from a header there. Also, it used to be a macro, so be modern and make a static inline from it. This makes the code actually readable. And as a preparation for next patches, rename it to vc_translate_ascii. vc_translate will be a wrapper for both unicode and this one. Signed-off-by: Jiri Slaby Link: https://lore.kernel.org/r/20200615074910.19267-10-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman

vt: vt_kern.h, remove extern from functions

2020-03-06T07:35:39+00:00

Unify the declarations of functions in vt_kern.h: some are with extern, some are not. Remove extern from the former as it is not needed for functions. Signed-off-by: Jiri Slaby Link: https://lore.kernel.org/r/20200219073951.16151-7-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman

vt: switch vt_dont_switch to bool

2020-03-06T07:35:39+00:00

vt_dont_switch is pure boolean, no need for whole char. Signed-off-by: Jiri Slaby Link: https://lore.kernel.org/r/20200219073951.16151-6-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman

vt: Remove vc_panic_force_write

2018-09-11T12:11:51+00:00

It was only used by the panic support in fbcon, which is now gone. Remove this now dead code too. Acked-by: Greg Kroah-Hartman Cc: Greg Kroah-Hartman Cc: Kees Cook Cc: Joe Perches Cc: Daniel Vetter Cc: Meng Xu Cc: Nicolas Pitre Cc: Thomas Meyer Cc: Mike Frysinger Cc: Bartlomiej Zolnierkiewicz Cc: Hans de Goede Cc: Thierry Reding Cc: David Lechner Cc: Philippe Ombredanne Cc: Thomas Gleixner Cc: Kate Stewart Signed-off-by: Daniel Vetter Link: https://patchwork.freedesktop.org/patch/msgid/20180822085405.10787-2-daniel.vetter@ffwll.ch

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

2017-11-02T10:10:55+00:00

Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart Reviewed-by: Philippe Ombredanne Reviewed-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman

tty: vgacon+sisusb, move scrolldelta to a common helper

2016-10-27T14:37:44+00:00

The code is mirrorred in scrolldelta implementations of both vgacon and sisusb. Let's move the code to a separate helper where we will perform a common cleanup and further changes. While we are moving the code, make it linear and save one indentation level. This is done by returning from the "!lines" then-branch immediatelly. This allows flushing the else-branch 1 level to the left, obviously. Few more new lines and comments were added too. And do not forget to export the helper function given sisusb can be built as module. Signed-off-by: Jiri Slaby Cc: Thomas Winischhofer Cc: Tomi Valkeinen Cc: Cc: Signed-off-by: Greg Kroah-Hartman