summaryrefslogtreecommitdiffstats
path: root/arch/x86/include/asm/clocksource.h
Commit message (Collapse)AuthorAgeFilesLines
* License cleanup: add SPDX GPL-2.0 license identifier to files with no licenseGreg Kroah-Hartman2017-11-021-0/+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>
* x86/vdso: Add VCLOCK_HVCLOCK vDSO clock read methodVitaly Kuznetsov2017-03-111-1/+2
| | | | | | | | | | | | | | | | | | Hyper-V TSC page clocksource is suitable for vDSO, however, the protocol defined by the hypervisor is different from VCLOCK_PVCLOCK. Implement the required support by adding hvclock_page VVAR. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Cc: Stephen Hemminger <sthemmin@microsoft.com> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: Dexuan Cui <decui@microsoft.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: devel@linuxdriverproject.org Cc: "K. Y. Srinivasan" <kys@microsoft.com> Cc: virtualization@lists.linux-foundation.org Link: http://lkml.kernel.org/r/20170303132142.25595-4-vkuznets@redhat.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* x86/vdso: Remove direct HPET access through the vDSOAndy Lutomirski2016-04-131-5/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Allowing user code to map the HPET is problematic. HPET implementations are notoriously buggy, and there are probably many machines on which even MMIO reads from bogus HPET addresses are problematic. We have a report that the Dell Precision M2800 with: ACPI: HPET 0x00000000C8FE6238 000038 (v01 DELL CBX3 01072009 AMI. 00000005) is either so slow when accessing the HPET or actually hangs in some regard, causing soft lockups to be reported if users do unexpected things to the HPET. The vclock HPET code has also always been a questionable speedup. Accessing an HPET is exceedingly slow (on the order of several microseconds), so the added overhead in requiring a syscall to read the HPET is a small fraction of the total code of accessing it. To avoid future problems, let's just delete the code entirely. In the long run, this could actually be a speedup. Waiman Long as a patch to optimize the case where multiple CPUs contend for the HPET, but that won't help unless all the accesses are mediated by the kernel. Reported-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by: Andy Lutomirski <luto@kernel.org> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Borislav Petkov <bp@alien8.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Waiman Long <Waiman.Long@hpe.com> Cc: Waiman Long <waiman.long@hpe.com> Link: http://lkml.kernel.org/r/d2f90bba98db9905041cff294646d290d378f67a.1460074438.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* x86/vdso: Disallow vvar access to vclock IO for never-used vclocksAndy Lutomirski2016-01-121-4/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It makes me uncomfortable that even modern systems grant every process direct read access to the HPET. While fixing this for real without regressing anything is a mess (unmapping the HPET is tricky because we don't adequately track all the mappings), we can do almost as well by tracking which vclocks have ever been used and only allowing pages associated with used vclocks to be faulted in. This will cause rogue programs that try to peek at the HPET to get SIGBUS instead on most systems. We can't restrict faults to vclock pages that are associated with the currently selected vclock due to a race: a process could start to access the HPET for the first time and race against a switch away from the HPET as the current clocksource. We can't segfault the process trying to peek at the HPET in this case, even though the process isn't going to do anything useful with the data. Signed-off-by: Andy Lutomirski <luto@kernel.org> Reviewed-by: Kees Cook <keescook@chromium.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/e79d06295625c02512277737ab55085a498ac5d8.1451446564.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* x86, vdso: Make vsyscall_gtod_data handling x86 genericStefani Seibold2014-03-181-4/+0
| | | | | | | | | | | | | This patch move the vsyscall_gtod_data handling out of vsyscall_64.c into an additonal file vsyscall_gtod.c to make the functionality available for x86 32 bit kernel. It also adds a new vsyscall_32.c which setup the VVAR page. Reviewed-by: Andy Lutomirski <luto@amacapital.net> Signed-off-by: Stefani Seibold <stefani@seibold.net> Link: http://lkml.kernel.org/r/1395094933-14252-2-git-send-email-stefani@seibold.net Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
* x86: pvclock: generic pvclock vsyscall initializationMarcelo Tosatti2012-11-271-0/+1
| | | | | | | | | Originally from Jeremy Fitzhardinge. Introduce generic, non hypervisor specific, pvclock initialization routines. Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
* clocksource: Change __ARCH_HAS_CLOCKSOURCE_DATA to a CONFIG optionH. Peter Anvin2011-07-211-2/+0
| | | | | | | | | | | | | | The machinery for __ARCH_HAS_CLOCKSOURCE_DATA assumed a file in asm-generic would be the default for architectures without their own file in asm/, but that is not how it works. Replace it with a Kconfig option instead. Link: http://lkml.kernel.org/r/4E288AA6.7090804@zytor.com Signed-off-by: H. Peter Anvin <hpa@zytor.com> Cc: Andy Lutomirski <luto@mit.edu> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Tony Luck <tony.luck@intel.com>
* x86-64: Move vread_tsc and vread_hpet into the vDSOAndy Lutomirski2011-07-141-1/+5
| | | | | | | | | The vsyscall page now consists entirely of trap instructions. Cc: John Stultz <johnstul@us.ibm.com> Signed-off-by: Andy Lutomirski <luto@mit.edu> Link: http://lkml.kernel.org/r/637648f303f2ef93af93bae25186e9a1bea093f5.1310639973.git.luto@mit.edu Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
* clocksource: Replace vread with generic arch dataAndy Lutomirski2011-07-131-0/+16
The vread field was bloating struct clocksource everywhere except x86_64, and I want to change the way this works on x86_64, so let's split it out into per-arch data. Cc: x86@kernel.org Cc: Clemens Ladisch <clemens@ladisch.de> Cc: linux-ia64@vger.kernel.org Cc: Tony Luck <tony.luck@intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: John Stultz <johnstul@us.ibm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andy Lutomirski <luto@mit.edu> Link: http://lkml.kernel.org/r/3ae5ec76a168eaaae63f08a2a1060b91aa0b7759.1310563276.git.luto@mit.edu Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>