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2020-05-15tty/sysrq: constify the the sysrq_key_op(s)Emil Velikov1-1/+1
All the users threat them as immutable - annotate them as such. Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jiri Slaby <jslaby@suse.com> Cc: linux-kernel@vger.kernel.org Signed-off-by: Emil Velikov <emil.l.velikov@gmail.com> Link: https://lore.kernel.org/r/20200513214351.2138580-3-emil.l.velikov@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-15tty/sysrq: constify the sysrq APIEmil Velikov1-8/+8
The user is not supposed to thinker with the underlying sysrq_key_op. Make that explicit by adding a handful of const notations. Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jiri Slaby <jslaby@suse.com> Cc: linux-kernel@vger.kernel.org Signed-off-by: Emil Velikov <emil.l.velikov@gmail.com> Link: https://lore.kernel.org/r/20200513214351.2138580-2-emil.l.velikov@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-15tty/sysrq: alpha: export and use __sysrq_get_key_op()Emil Velikov1-1/+1
Export a pointer to the sysrq_get_key_op(). This way we can cleanly unregister it, instead of the current solutions of modifuing it inplace. Since __sysrq_get_key_op() is no longer used externally, let's make it a static function. This patch will allow us to limit access to each and every sysrq op and constify the sysrq handling. Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jiri Slaby <jslaby@suse.com> Cc: linux-kernel@vger.kernel.org Cc: Richard Henderson <rth@twiddle.net> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: Matt Turner <mattst88@gmail.com> Cc: linux-alpha@vger.kernel.org Signed-off-by: Emil Velikov <emil.l.velikov@gmail.com> Link: https://lore.kernel.org/r/20200513214351.2138580-1-emil.l.velikov@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-03-07sysctl/sysrq: Remove __sysrq_enabled copyDmitry Safonov1-0/+7
Many embedded boards have a disconnected TTL level serial which can generate some garbage that can lead to spurious false sysrq detects. Currently, sysrq can be either completely disabled for serial console or always disabled (with CONFIG_MAGIC_SYSRQ_SERIAL), since commit 732dbf3a6104 ("serial: do not accept sysrq characters via serial port") At Arista, we have such boards that can generate BREAK and random garbage. While disabling sysrq for serial console would solve the problem with spurious false sysrq triggers, it's also desirable to have a way to enable sysrq back. Having the way to enable sysrq was beneficial to debug lockups with a manual investigation in field and on the other side preventing false sysrq detections. As a preparation to add sysrq_toggle_support() call into uart, remove a private copy of sysrq_enabled from sysctl - it should reflect the actual status of sysrq. Furthermore, the private copy isn't correct already in case sysrq_always_enabled is true. So, remove __sysrq_enabled and use a getter-helper sysrq_mask() to check sysrq_key_op enabled status. Cc: Iurii Zaikin <yzaikin@google.com> Cc: Jiri Slaby <jslaby@suse.com> Cc: Luis Chamberlain <mcgrof@kernel.org> Cc: Kees Cook <keescook@chromium.org> Cc: linux-fsdevel@vger.kernel.org Signed-off-by: Dmitry Safonov <dima@arista.com> Link: https://lore.kernel.org/r/20200302175135.269397-2-dima@arista.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-02License cleanup: add SPDX GPL-2.0 license identifier to files with no licenseGreg Kroah-Hartman1-0/+1
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 <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-17sysrq: Allow magic SysRq key functions to be disabled through KconfigBen Hutchings1-3/+0
Turn the initial value of sysctl kernel.sysrq (SYSRQ_DEFAULT_ENABLE) into a Kconfig variable. Original version by Bastian Blank <waldi@debian.org>. Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2011-01-24Input: sysrq - ensure sysrq_enabled and __sysrq_enabled are consistentAndy Whitcroft1-0/+3
Currently sysrq_enabled and __sysrq_enabled are initialised separately and inconsistently, leading to sysrq being actually enabled by reported as not enabled in sysfs. The first change to the sysfs configurable synchronises these two: static int __read_mostly sysrq_enabled = 1; static int __sysrq_enabled; Add a common define to carry the default for these preventing them becoming out of sync again. Default this to 1 to mirror previous behaviour. Signed-off-by: Andy Whitcroft <apw@canonical.com> Cc: stable@kernel.org Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
2010-08-21Input: sysrq - drop tty argument form handle_sysrq()Dmitry Torokhov1-7/+5
Sysrq operations do not accept tty argument anymore so no need to pass it to us. [Stephen Rothwell <sfr@canb.auug.org.au>: fix build breakage in drm code caused by sysrq using bool but not including linux/types.h] [Sachin Sant <sachinp@in.ibm.com>: fix build breakage in s390 keyboadr driver] Acked-by: Alan Cox <alan@lxorguk.ukuu.org.uk> Acked-by: Jason Wessel <jason.wessel@windriver.com> Acked-by: Greg Kroah-Hartman <gregkh@suse.de> Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
2010-08-20Input: sysrq - drop tty argument from sysrq ops handlersDmitry Torokhov1-1/+5
Noone is using tty argument so let's get rid of it. Acked-by: Alan Cox <alan@lxorguk.ukuu.org.uk> Acked-by: Jason Wessel <jason.wessel@windriver.com> Acked-by: Greg Kroah-Hartman <gregkh@suse.de> Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
2010-07-22sysrq,kdb: Use __handle_sysrq() for kdb's sysrq functionJason Wessel1-0/+1
The kdb code should not toggle the sysrq state in case an end user wants to try and resume the normal kernel execution. Signed-off-by: Jason Wessel <jason.wessel@windriver.com> Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
2010-04-14Input: implement SysRq as a separate input handlerDmitry Torokhov1-15/+8
Instead of keeping SysRq support inside of legacy keyboard driver split it out into a separate input handler (filter). This stops most SysRq input events from leaking into evdev clients (some events, such as first SysRq scancode - not keycode - event, are still leaked into both legacy keyboard and evdev). [martinez.javier@gmail.com: fix compile error when CONFIG_MAGIC_SYSRQ is not defined] Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
2009-07-07linux/sysrq.h needs linux/errno.hTobias Doerffel1-0/+2
In include/linux/sysrq.h the constant EINVAL is being used but is undefined if include/linux/errno.h is not included before. Fix this by adding #include <linux/errno.h> at the beginning. Signed-off-by: Tobias Doerffel <tobias.doerffel@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2006-12-13[PATCH] debug: add sysrq_always_enabled boot optionIngo Molnar1-4/+18
Most distributions enable sysrq support but set it to 0 by default. Add a sysrq_always_enabled boot option to always-enable sysrq keys. Useful for debugging - without having to modify the disribution's config files (which might not be possible if the kernel is on a live CD, etc.). Also, while at it, clean up the sysrq interfaces. [bunk@stusta.de: make sysrq_always_enabled_setup() static] Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Adrian Bunk <bunk@stusta.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-05IRQ: Maintain regs pointer globally rather than passing to IRQ handlersDavid Howells1-3/+3
Maintain a per-CPU global "struct pt_regs *" variable which can be used instead of passing regs around manually through all ~1800 interrupt handlers in the Linux kernel. The regs pointer is used in few places, but it potentially costs both stack space and code to pass it around. On the FRV arch, removing the regs parameter from all the genirq function results in a 20% speed up of the IRQ exit path (ie: from leaving timer_interrupt() to leaving do_IRQ()). Where appropriate, an arch may override the generic storage facility and do something different with the variable. On FRV, for instance, the address is maintained in GR28 at all times inside the kernel as part of general exception handling. Having looked over the code, it appears that the parameter may be handed down through up to twenty or so layers of functions. Consider a USB character device attached to a USB hub, attached to a USB controller that posts its interrupts through a cascaded auxiliary interrupt controller. A character device driver may want to pass regs to the sysrq handler through the input layer which adds another few layers of parameter passing. I've build this code with allyesconfig for x86_64 and i386. I've runtested the main part of the code on FRV and i386, though I can't test most of the drivers. I've also done partial conversion for powerpc and MIPS - these at least compile with minimal configurations. This will affect all archs. Mostly the changes should be relatively easy. Take do_IRQ(), store the regs pointer at the beginning, saving the old one: struct pt_regs *old_regs = set_irq_regs(regs); And put the old one back at the end: set_irq_regs(old_regs); Don't pass regs through to generic_handle_irq() or __do_IRQ(). In timer_interrupt(), this sort of change will be necessary: - update_process_times(user_mode(regs)); - profile_tick(CPU_PROFILING, regs); + update_process_times(user_mode(get_irq_regs())); + profile_tick(CPU_PROFILING); I'd like to move update_process_times()'s use of get_irq_regs() into itself, except that i386, alone of the archs, uses something other than user_mode(). Some notes on the interrupt handling in the drivers: (*) input_dev() is now gone entirely. The regs pointer is no longer stored in the input_dev struct. (*) finish_unlinks() in drivers/usb/host/ohci-q.c needs checking. It does something different depending on whether it's been supplied with a regs pointer or not. (*) Various IRQ handler function pointers have been moved to type irq_handler_t. Signed-Off-By: David Howells <dhowells@redhat.com> (cherry picked from 1b16e7ac850969f38b375e511e3fa2f474a33867 commit)
2006-10-01[PATCH] Prevent multiple inclusion of linux/sysrq.hThomas Petazzoni1-0/+4
Prevent multiple inclusions of include/linux/sysrq.h using traditional #ifndef..#endif. Signed-off-by: Thomas Petazzoni <thomas.petazzoni@enix.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-04-26Don't include linux/config.h from anywhere else in include/David Woodhouse1-1/+0
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
2005-04-17Linux-2.6.12-rc2Linus Torvalds1-0/+60
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!