user/sven/linux.git/kernel/irq/proc.c, branch v4.14.266

genirq/proc: Reject invalid affinity masks (again)

2020-02-28T15:36:15Z

commit cba6437a1854fde5934098ec3bd0ee83af3129f5 upstream. Qian Cai reported that the WARN_ON() in the x86/msi affinity setting code, which catches cases where the affinity setting is not done on the CPU which is the current target of the interrupt, triggers during CPU hotplug stress testing. It turns out that the warning which was added with the commit addressing the MSI affinity race unearthed yet another long standing bug. If user space writes a bogus affinity mask, i.e. it contains no online CPUs, then it calls irq_select_affinity_usr(). This was introduced for ALPHA in eee45269b0f5 ("[PATCH] Alpha: convert to generic irq framework (generic part)") and subsequently made available for all architectures in 18404756765c ("genirq: Expose default irq affinity mask (take 3)") which introduced the circumvention of the affinity setting restrictions for interrupt which cannot be moved in process context. The whole exercise is bogus in various aspects: 1) If the interrupt is already started up then there is absolutely no point to honour a bogus interrupt affinity setting from user space. The interrupt is already assigned to an online CPU and it does not make any sense to reassign it to some other randomly chosen online CPU. 2) If the interupt is not yet started up then there is no point either. A subsequent startup of the interrupt will invoke irq_setup_affinity() anyway which will chose a valid target CPU. So the only correct solution is to just return -EINVAL in case user space wrote an affinity mask which does not contain any online CPUs, except for ALPHA which has it's own magic sauce for this. Fixes: 18404756765c ("genirq: Expose default irq affinity mask (take 3)") Reported-by: Qian Cai Signed-off-by: Thomas Gleixner Tested-by: Qian Cai Link: https://lkml.kernel.org/r/878sl8xdbm.fsf@nanos.tec.linutronix.de Signed-off-by: Greg Kroah-Hartman

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

2017-11-02T10:10:55Z

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

genirq/proc: Avoid uninitalized variable warning

2017-08-25T20:40:26Z

kernel/irq/proc.c: In function ‘show_irq_affinity’: include/linux/cpumask.h:24:29: warning: ‘mask’ may be used uninitialized in this function [-Wmaybe-uninitialized] #define cpumask_bits(maskp) ((maskp)->bits) gcc is silly, but admittedly it can't know that this won't be called with anything else than the enumerated constants. Shut up the warning by creating a default clause. Fixes: 6bc6d4abd22e ("genirq/proc: Use the the accessor to report the effective affinity Signed-off-by: Thomas Gleixner

genirq: Fix semicolon.cocci warnings

2017-08-25T20:40:25Z

kernel/irq/proc.c:69:2-3: Unneeded semicolon Remove unneeded semicolon. Generated by: scripts/coccinelle/misc/semicolon.cocci Fixes: 0d3f54257dc3 ("genirq: Introduce effective affinity mask") Signed-off-by: Fengguang Wu Signed-off-by: Thomas Gleixner Cc: kbuild-all@01.org Link: http://lkml.kernel.org/r/20170822075053.GA93890@lkp-hsx02

genirq/proc: Use the the accessor to report the effective affinity

2017-08-18T08:54:39Z

If CONFIG_GENERIC_IRQ_EFFECTIVE_AFF_MASK is defined, but that the interrupt is not single target, the effective affinity reported in /proc/irq/x/effective_affinity will be empty, which is not the truth. Instead, use the accessor to report the affinity, which will pick the right mask. Signed-off-by: Marc Zyngier Signed-off-by: Thomas Gleixner Cc: Andrew Lunn Cc: James Hogan Cc: Jason Cooper Cc: Paul Burton Cc: Chris Zankel Cc: Kevin Cernekee Cc: Wei Xu Cc: Max Filippov Cc: Florian Fainelli Cc: Gregory Clement Cc: Matt Redfearn Cc: Sebastian Hesselbarth Link: http://lkml.kernel.org/r/20170818083925.10108-3-marc.zyngier@arm.com

genirq: Introduce effective affinity mask

2017-06-22T16:21:20Z

There is currently no way to evaluate the effective affinity mask of a given interrupt. Many irq chips allow only a single target CPU or a subset of CPUs in the affinity mask. Updating the mask at the time of setting the affinity to the subset would be counterproductive because information for cpu hotplug about assigned interrupt affinities gets lost. On CPU hotplug it's also pointless to force migrate an interrupt, which is not targeted at the CPU effectively. But currently the information is not available. Provide a seperate mask to be updated by the irq_chip->irq_set_affinity() implementations. Implement the read only proc files so the user can see the effective mask as well w/o trying to deduce it from /proc/interrupts. Signed-off-by: Thomas Gleixner Cc: Jens Axboe Cc: Marc Zyngier Cc: Michael Ellerman Cc: Keith Busch Cc: Peter Zijlstra Cc: Christoph Hellwig Link: http://lkml.kernel.org/r/20170619235446.247834245@linutronix.de

genirq/proc: Replace ever repeating type cast

2017-06-22T16:21:20Z

The proc file setup repeats the same ugly type cast for the irq number over and over. Do it once and hand in the local void pointer. Signed-off-by: Thomas Gleixner Cc: Jens Axboe Cc: Marc Zyngier Cc: Michael Ellerman Cc: Keith Busch Cc: Peter Zijlstra Cc: Christoph Hellwig Link: http://lkml.kernel.org/r/20170619235446.160866358@linutronix.de

genirq: Remove pointless arg from show_irq_affinity

2017-06-22T16:21:19Z

The third argument of the internal helper function is unused. Remove it. Signed-off-by: Thomas Gleixner Cc: Jens Axboe Cc: Marc Zyngier Cc: Michael Ellerman Cc: Keith Busch Cc: Peter Zijlstra Cc: Christoph Hellwig Link: http://lkml.kernel.org/r/20170619235446.004958600@linutronix.de

genirq: Remove mask argument from setup_affinity()

2017-06-22T16:21:14Z

No point to have this alloc/free dance of cpumasks. Provide a static mask for setup_affinity() and protect it proper. Signed-off-by: Thomas Gleixner Cc: Jens Axboe Cc: Marc Zyngier Cc: Michael Ellerman Cc: Keith Busch Cc: Peter Zijlstra Cc: Christoph Hellwig Link: http://lkml.kernel.org/r/20170619235444.851571573@linutronix.de

genirq: Fix /proc/interrupts output alignment

2017-02-10T19:17:52Z

If the irq_desc being output does not have a domain associated the information following the 'name' is not aligned correctly. Signed-off-by: H Hartley Sweeten Link: http://lkml.kernel.org/r/20170210165416.5629-1-hsweeten@visionengravers.com Signed-off-by: Thomas Gleixner