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* fs: rename __mnt_{want,drop}_write*() helpersAmir Goldstein2023-09-111-2/+2
| | | | | | | | | | | | | | | Before exporting these helpers to modules, make their names more meaningful. The names mnt_{get,put)_write_access*() were chosen, because they rhyme with the inode {get,put)_write_access() helpers, which have a very close meaning for the inode object. Suggested-by: Christian Brauner <brauner@kernel.org> Link: https://lore.kernel.org/r/20230817-anfechtbar-ruhelosigkeit-8c6cca8443fc@brauner/ Signed-off-by: Amir Goldstein <amir73il@gmail.com> Message-Id: <20230908132900.2983519-2-amir73il@gmail.com> Signed-off-by: Christian Brauner <brauner@kernel.org>
* Merge tag 'audit-pr-20230829' of ↵Linus Torvalds2023-08-301-1/+1
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/audit Pull audit updates from Paul Moore: "Six audit patches, the highlights are: - Add an explicit cond_resched() call when generating PATH records Certain tracefs/debugfs operations can generate a *lot* of audit PATH entries and if one has an aggressive system configuration (not the default) this can cause a soft lockup in the audit code as it works to process all of these new entries. This is in sharp contrast to the common case where only one or two PATH entries are logged. In order to fix this corner case without excessively impacting the common case we're adding a single cond_rescued() call between two of the most intensive loops in the __audit_inode_child() function. - Various minor cleanups We removed a conditional header file as the included header already had the necessary logic in place, fixed a dummy function's return value, and the usual collection of checkpatch.pl noise (whitespace, brace, and trailing statement tweaks)" * tag 'audit-pr-20230829' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/audit: audit: move trailing statements to next line audit: cleanup function braces and assignment-in-if-condition audit: add space before parenthesis and around '=', "==", and '<' audit: fix possible soft lockup in __audit_inode_child() audit: correct audit_filter_inodes() definition audit: include security.h unconditionally
| * audit: add space before parenthesis and around '=', "==", and '<'Atul Kumar Pant2023-08-151-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | Fixes following checkpatch.pl issue: ERROR: space required before the open parenthesis '(' ERROR: spaces required around that '=' ERROR: spaces required around that '<' ERROR: spaces required around that '==' Signed-off-by: Atul Kumar Pant <atulpant.linux@gmail.com> [PM: subject line tweaks] Signed-off-by: Paul Moore <paul@paul-moore.com>
* | acct: replace all non-returning strlcpy with strscpyAzeem Shaikh2023-08-181-1/+1
|/ | | | | | | | | | | | | | | | strlcpy() reads the entire source buffer first. This read may exceed the destination size limit. This is both inefficient and can lead to linear read overflows if a source string is not NUL-terminated [1]. In an effort to remove strlcpy() completely [2], replace strlcpy() here with strscpy(). No return values were used, so direct replacement is safe. [1] https://www.kernel.org/doc/html/latest/process/deprecated.html#strlcpy [2] https://github.com/KSPP/linux/issues/89 Link: https://lkml.kernel.org/r/20230710011748.3538624-1-azeemshaikh38@gmail.com Signed-off-by: Azeem Shaikh <azeemshaikh38@gmail.com> Cc: Kees Cook <keescook@chromium.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* acct: fix potential integer overflow in encode_comp_t()Zheng Yejian2022-11-301-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | The integer overflow is descripted with following codes: > 317 static comp_t encode_comp_t(u64 value) > 318 { > 319 int exp, rnd; ...... > 341 exp <<= MANTSIZE; > 342 exp += value; > 343 return exp; > 344 } Currently comp_t is defined as type of '__u16', but the variable 'exp' is type of 'int', so overflow would happen when variable 'exp' in line 343 is greater than 65535. Link: https://lkml.kernel.org/r/20210515140631.369106-3-zhengyejian1@huawei.com Signed-off-by: Zheng Yejian <zhengyejian1@huawei.com> Cc: Hanjun Guo <guohanjun@huawei.com> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Zhang Jinhao <zhangjinhao2@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* acct: fix accuracy loss for input value of encode_comp_t()Zheng Yejian2022-11-301-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Patch series "Fix encode_comp_t()". Type conversion in encode_comp_t() may look a bit problematic. This patch (of 2): See calculation of ac_{u,s}time in fill_ac(): > ac->ac_utime = encode_comp_t(nsec_to_AHZ(pacct->ac_utime)); > ac->ac_stime = encode_comp_t(nsec_to_AHZ(pacct->ac_stime)); Return value of nsec_to_AHZ() is always type of 'u64', but it is handled as type of 'unsigned long' in encode_comp_t, and accuracy loss would happen on 32-bit platform when 'unsigned long' value is 32-bit-width. So 'u64' value of encode_comp_t() may look better. Link: https://lkml.kernel.org/r/20210515140631.369106-1-zhengyejian1@huawei.com Link: https://lkml.kernel.org/r/20210515140631.369106-2-zhengyejian1@huawei.com Signed-off-by: Zheng Yejian <zhengyejian1@huawei.com> Cc: Hanjun Guo <guohanjun@huawei.com> Cc: Randy Dunlap <rdunlap@infradead.org> # build-tested Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Zhang Jinhao <zhangjinhao2@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* acct: use VMA iterator instead of linked listMatthew Wilcox (Oracle)2022-09-261-6/+5
| | | | | | | | | | | | | | | | | | The VMA iterator is faster than the linked list. Link: https://lkml.kernel.org/r/20220906194824.2110408-47-Liam.Howlett@oracle.com Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: Davidlohr Bueso <dave@stgolabs.net> Tested-by: Yu Zhao <yuzhao@google.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: David Hildenbrand <david@redhat.com> Cc: David Howells <dhowells@redhat.com> Cc: SeongJae Park <sj@kernel.org> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* kernel/acct: move acct sysctls to its own filetangmeng2022-04-061-1/+21
| | | | | | | | | | | | | | | | | kernel/sysctl.c is a kitchen sink where everyone leaves their dirty dishes, this makes it very difficult to maintain. To help with this maintenance let's start by moving sysctls to places where they actually belong. The proc sysctl maintainers do not want to know what sysctl knobs you wish to add for your own piece of code, we just care about the core logic. All filesystem syctls now get reviewed by fs folks. This commit follows the commit of fs, move the acct sysctl to its own file, kernel/acct.c. Signed-off-by: tangmeng <tangmeng@uniontech.com> Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
* kernel: remove spurious blkdev.h includesChristoph Hellwig2021-10-181-1/+0
| | | | | | | | | | Various files have acquired spurious includes of <linux/blkdev.h> over time. Remove them. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Link: https://lore.kernel.org/r/20210920123328.1399408-7-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
* kernel/acct.c: use dedicated helper to access rlimit valuesYang Yang2021-09-081-1/+1
| | | | | | | | | | | | | | | Use rlimit() helper instead of manually writing whole chain from task to rlimit value. See patch "posix-cpu-timers: Use dedicated helper to access rlimit values". Link: https://lkml.kernel.org/r/20210728030822.524789-1-yang.yang29@zte.com.cn Signed-off-by: Yang Yang <yang.yang29@zte.com.cn> Reported-by: Zeal Robot <zealci@zte.com.cn> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: sh_def@163.com <sh_def@163.com> Cc: Yang Yang <yang.yang29@zte.com.cn> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* kernel/acct.c: use #elif instead of #end and #elifHui Su2020-12-151-5/+2
| | | | | | | | | | Cleanup: use #elif instead of #end and #elif. Link: https://lkml.kernel.org/r/20201015150736.GA91603@rlk Signed-off-by: Hui Su <sh_def@163.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* kernel: acct.c: fix some kernel-doc nitsRandy Dunlap2020-10-161-5/+3
| | | | | | | | | | | | Fix kernel-doc notation to use the documented Returns: syntax and place the function description for acct_process() on the first line where it should be. Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Link: https://lkml.kernel.org/r/b4c33e5d-98e8-0c47-77b6-ac1859f94d7f@infradead.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* kernel/: fix repeated words in commentsRandy Dunlap2020-10-161-1/+1
| | | | | | | | | | | | | Fix multiple occurrences of duplicated words in kernel/. Fix one typo/spello on the same line as a duplicate word. Change one instance of "the the" to "that the". Otherwise just drop one of the repeated words. Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Link: https://lkml.kernel.org/r/98202fa6-8919-ef63-9efe-c0fad5ca7af1@infradead.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mmap locking API: convert mmap_sem commentsMichel Lespinasse2020-06-091-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | Convert comments that reference mmap_sem to reference mmap_lock instead. [akpm@linux-foundation.org: fix up linux-next leftovers] [akpm@linux-foundation.org: s/lockaphore/lock/, per Vlastimil] [akpm@linux-foundation.org: more linux-next fixups, per Michel] Signed-off-by: Michel Lespinasse <walken@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com> Cc: Davidlohr Bueso <dbueso@suse.de> Cc: David Rientjes <rientjes@google.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Jerome Glisse <jglisse@redhat.com> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Laurent Dufour <ldufour@linux.ibm.com> Cc: Liam Howlett <Liam.Howlett@oracle.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ying Han <yinghan@google.com> Link: http://lkml.kernel.org/r/20200520052908.204642-13-walken@google.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mmap locking API: use coccinelle to convert mmap_sem rwsem call sitesMichel Lespinasse2020-06-091-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This change converts the existing mmap_sem rwsem calls to use the new mmap locking API instead. The change is generated using coccinelle with the following rule: // spatch --sp-file mmap_lock_api.cocci --in-place --include-headers --dir . @@ expression mm; @@ ( -init_rwsem +mmap_init_lock | -down_write +mmap_write_lock | -down_write_killable +mmap_write_lock_killable | -down_write_trylock +mmap_write_trylock | -up_write +mmap_write_unlock | -downgrade_write +mmap_write_downgrade | -down_read +mmap_read_lock | -down_read_killable +mmap_read_lock_killable | -down_read_trylock +mmap_read_trylock | -up_read +mmap_read_unlock ) -(&mm->mmap_sem) +(mm) Signed-off-by: Michel Lespinasse <walken@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com> Reviewed-by: Laurent Dufour <ldufour@linux.ibm.com> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Cc: Davidlohr Bueso <dbueso@suse.de> Cc: David Rientjes <rientjes@google.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Jerome Glisse <jglisse@redhat.com> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Liam Howlett <Liam.Howlett@oracle.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ying Han <yinghan@google.com> Link: http://lkml.kernel.org/r/20200520052908.204642-5-walken@google.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* acct: stop using get_seconds()Arnd Bergmann2019-12-181-1/+3
| | | | | | | | | | | | | | | | | | In 'struct acct', 'struct acct_v3', and 'struct taskstats' we have a 32-bit 'ac_btime' field containing an absolute time value, which will overflow in year 2106. There are two possible ways to deal with it: a) let it overflow and have user space code deal with reconstructing the data based on the current time, or b) truncate the times based on the range of the u32 type. Neither of them solves the actual problem. Pick the second one to best document what the issue is, and have someone fix it in a future version. Signed-off-by: Arnd Bergmann <arnd@arndb.de>
* acct_on(): don't mess with freeze protectionAl Viro2019-04-041-2/+2
| | | | | | | | | | | | | | | | What happens there is that we are replacing file->path.mnt of a file we'd just opened with a clone and we need the write count contribution to be transferred from original mount to new one. That's it. We do *NOT* want any kind of freeze protection for the duration of switchover. IOW, we should just use __mnt_{want,drop}_write() for that switchover; no need to bother with mnt_{want,drop}_write() there. Tested-by: Amir Goldstein <amir73il@gmail.com> Reported-by: syzbot+2a73a6ea9507b7112141@syzkaller.appspotmail.com Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* kernel/acct.c: fix the acct->needcheck check in check_free_space()Oleg Nesterov2018-01-041-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | As Tsukada explains, the time_is_before_jiffies(acct->needcheck) check is very wrong, we need time_is_after_jiffies() to make sys_acct() work. Ignoring the overflows, the code should "goto out" if needcheck > jiffies, while currently it checks "needcheck < jiffies" and thus in the likely case check_free_space() does nothing until jiffies overflow. In particular this means that sys_acct() is simply broken, acct_on() sets acct->needcheck = jiffies and expects that check_free_space() should set acct->active = 1 after the free-space check, but this won't happen if jiffies increments in between. This was broken by commit 32dc73086015 ("get rid of timer in kern/acct.c") in 2011, then another (correct) commit 795a2f22a8ea ("acct() should honour the limits from the very beginning") made the problem more visible. Link: http://lkml.kernel.org/r/20171213133940.GA6554@redhat.com Fixes: 32dc73086015 ("get rid of timer in kern/acct.c") Reported-by: TSUKADA Koutaro <tsukada@ascade.co.jp> Suggested-by: TSUKADA Koutaro <tsukada@ascade.co.jp> Signed-off-by: Oleg Nesterov <oleg@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge branch 'linus' into locking/core, to resolve conflictsIngo Molnar2017-11-071-0/+1
|\ | | | | | | | | | | | | | | | | | | Conflicts: include/linux/compiler-clang.h include/linux/compiler-gcc.h include/linux/compiler-intel.h include/uapi/linux/stddef.h Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * 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>
* | locking/atomics: COCCINELLE/treewide: Convert trivial ACCESS_ONCE() patterns ↵Mark Rutland2017-10-251-2/+2
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | to READ_ONCE()/WRITE_ONCE() Please do not apply this to mainline directly, instead please re-run the coccinelle script shown below and apply its output. For several reasons, it is desirable to use {READ,WRITE}_ONCE() in preference to ACCESS_ONCE(), and new code is expected to use one of the former. So far, there's been no reason to change most existing uses of ACCESS_ONCE(), as these aren't harmful, and changing them results in churn. However, for some features, the read/write distinction is critical to correct operation. To distinguish these cases, separate read/write accessors must be used. This patch migrates (most) remaining ACCESS_ONCE() instances to {READ,WRITE}_ONCE(), using the following coccinelle script: ---- // Convert trivial ACCESS_ONCE() uses to equivalent READ_ONCE() and // WRITE_ONCE() // $ make coccicheck COCCI=/home/mark/once.cocci SPFLAGS="--include-headers" MODE=patch virtual patch @ depends on patch @ expression E1, E2; @@ - ACCESS_ONCE(E1) = E2 + WRITE_ONCE(E1, E2) @ depends on patch @ expression E; @@ - ACCESS_ONCE(E) + READ_ONCE(E) ---- Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: davem@davemloft.net Cc: linux-arch@vger.kernel.org Cc: mpe@ellerman.id.au Cc: shuah@kernel.org Cc: snitzer@redhat.com Cc: thor.thayer@linux.intel.com Cc: tj@kernel.org Cc: viro@zeniv.linux.org.uk Cc: will.deacon@arm.com Link: http://lkml.kernel.org/r/1508792849-3115-19-git-send-email-paulmck@linux.vnet.ibm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* fs: make the buf argument to __kernel_write a void pointerChristoph Hellwig2017-09-041-1/+1
| | | | | | | | This matches kernel_read and kernel_write and avoids any need for casts in the callers. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* sched/headers: Prepare to move cputime functionality from <linux/sched.h> ↵Ingo Molnar2017-03-021-0/+2
| | | | | | | | | | | | | | | | into <linux/sched/cputime.h> Introduce a trivial, mostly empty <linux/sched/cputime.h> header to prepare for the moving of cputime functionality out of sched.h. Update all code that relies on these facilities. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* acct: Convert obsolete cputime type to nsecsFrederic Weisbecker2017-02-011-4/+5
| | | | | | | | | | | | | | | | | | | | | | Use the new nsec based cputime accessors as part of the whole cputime conversion from cputime_t to nsecs. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Stanislaw Gruszka <sgruszka@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Cc: Wanpeng Li <wanpeng.li@hotmail.com> Link: http://lkml.kernel.org/r/1485832191-26889-13-git-send-email-fweisbec@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* sched/cputime: Introduce special task_cputime_t() API to return old-typed ↵Frederic Weisbecker2017-02-011-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | cputime This API returns a task's cputime in cputime_t in order to ease the conversion of cputime internals to use nsecs units instead. Blindly converting all cputime readers to use this API now will later let us convert more smoothly and step by step all these places to use the new nsec based cputime. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Stanislaw Gruszka <sgruszka@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Cc: Wanpeng Li <wanpeng.li@hotmail.com> Link: http://lkml.kernel.org/r/1485832191-26889-7-git-send-email-fweisbec@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* acct: check FMODE_CAN_WRITEAl Viro2015-04-111-1/+1
| | | | | | it's not calling ->write() directly anymore. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* new fs_pin killing logicsAl Viro2015-01-251-47/+34
| | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* get rid of the second argument of acct_kill()Al Viro2015-01-251-10/+7
| | | | | | | | Replace the old ns->bacct only with NULL and only if it still points to acct. And assign the new value to it *before* calling acct_kill() in acct_on(). That way we don't need to pass the new acct to acct_kill(). Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* take count and rcu_head out of fs_pinAl Viro2015-01-251-6/+8
| | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* pull bumping refcount into ->kill()Al Viro2015-01-251-0/+6
| | | | | | | there will be one more change of ->kill() calling conventions; this isn't final. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* kill pin_put()Al Viro2015-01-251-4/+10
| | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* acct: eliminate compile warningYing Xue2014-10-091-5/+9
| | | | | | | | | | | | If ACCT_VERSION is not defined to 3, below warning appears: CC kernel/acct.o kernel/acct.c: In function `do_acct_process': kernel/acct.c:475:24: warning: unused variable `ns' [-Wunused-variable] [akpm@linux-foundation.org: retain the local for code size improvements Signed-off-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* kernel/acct.c: fix coding style warnings and errorsIonut Alexa2014-08-071-12/+16
| | | | | | Signed-off-by: Ionut Alexa <ionut.m.alexa@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* death to mnt_pinnedAl Viro2014-08-071-5/+19
| | | | | | | | | | | | | | | | | | | | | Rather than playing silly buggers with vfsmount refcounts, just have acct_on() ask fs/namespace.c for internal clone of file->f_path.mnt and replace it with said clone. Then attach the pin to original vfsmount. Voila - the clone will be alive until the file gets closed, making sure that underlying superblock remains active, etc., and we can drop the original vfsmount, so that it's not kept busy. If the file lives until the final mntput of the original vfsmount, we'll notice that there's an fs_pin (one in bsd_acct_struct that holds that file) and mnt_pin_kill() will take it out. Since ->kill() is synchronous, we won't proceed past that point until these files are closed (and private clones of our vfsmount are gone), so we get the same ordering warranties we used to get. mnt_pin()/mnt_unpin()/->mnt_pinned is gone now, and good riddance - it never became usable outside of kernel/acct.c (and racy wrt umount even there). Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* take fs_pin stuff to fs/*Al Viro2014-08-071-95/+32
| | | | | | | | | | | | | | | Add a new field to fs_pin - kill(pin). That's what umount and r/o remount will be calling for all pins attached to vfsmount and superblock resp. Called after bumping the refcount, so it won't go away under us. Dropping the refcount is responsibility of the instance. All generic stuff moved to fs/fs_pin.c; the next step will rip all the knowledge of kernel/acct.c from fs/super.c and fs/namespace.c. After that - death to mnt_pin(); it was intended to be usable as generic mechanism for code that wants to attach objects to vfsmount, so that they would not make the sucker busy and would get killed on umount. Never got it right; it remained acct.c-specific all along. Now it's very close to being killable. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* start carving bsd_acct_struct upAl Viro2014-08-071-19/+23
| | | | | | | | pull generic parts into struct fs_pin. Eventually we want those to replace mnt_pin()/mnt_unpin() mess; that stuff will move to fs/*. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* acct: move mnt_pin() upwards.Al Viro2014-08-071-2/+1
| | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* make acct_kill() wait for file closing.Al Viro2014-08-071-3/+17
| | | | | | | Do actual closing of file via schedule_work(). And use __fput_sync() there. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* acct: get rid of acct_lock for acct->countAl Viro2014-08-071-33/+52
| | | | | | | | | * make acct->count atomic and acct freeing - rcu-delayed. * instead of grabbing acct_lock around the places where we take a reference, do that under rcu_read_lock() with atomic_long_inc_not_zero(). * have the new acct locked before making ns->bacct point to it Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* acct: get rid of acct_listAl Viro2014-08-071-80/+55
| | | | | | | | Put these suckers on per-vfsmount and per-superblock lists instead. Note: right now it's still acct_lock for everything, but that's going to change. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* acct: simplify check_free_space()Al Viro2014-08-071-39/+11
| | | | | | | | | a) file can't be NULL b) file can't be changed under us c) all writes are serialized by acct->lock; no need to mess with spinlock there. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* acct: new lifetime rulesAl Viro2014-08-071-106/+114
| | | | | | | | | | | | | | | | | | | | Do not reuse bsd_acct_struct after closing the damn thing. Structure lifetime is controlled by refcount now. We also have a mutex in there, held over closing and writing (the file is O_APPEND, so we are not losing any concurrency). As the result, we do not need to bother with get_file()/fput() on log write anymore. Moreover, do_acct_process() only needs acct itself; file and pidns are picked from it. Killed instances are distinguished by having NULL ->ns. Refcount is protected by acct_lock; anybody taking the mutex needs to grab a reference first. The things will get a lot simpler in the next commits - this is just the minimal chunk switching to the new lifetime rules. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* acct: serialize acct_on()Al Viro2014-08-071-0/+4
| | | | | | brute-force - on a global mutex that isn't nested into anything. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* acct() should honour the limits from the very beginningAl Viro2014-08-071-2/+2
| | | | | | We need to check free space on the first write to freshly opened log. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* split the slow path in acct_process() offAl Viro2014-08-071-22/+28
| | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* separate namespace-independent parts of filling acct_tAl Viro2014-08-071-47/+51
| | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* acct: switch to __kernel_write()Al Viro2014-08-071-19/+12
| | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* acct: encode_comp_t(0) is 0, fortunately...Al Viro2014-08-071-3/+0
| | | | | | | | | | | | | | | | | | | | | | There was an amusing bogosity in ac_rw calculation - it tried to do encode_comp_t(encode_comp_t(0) / 1024). Seeing that comp_t is a 3-bit exponent + 13-bit mantissa... it's a good thing that 0 is represented by all-bits-clear. The history of that one is interesting - it was introduced in 2.1.68pre1, when acct.c had been reworked and moved to separate file. Two months later (2.1.86) somebody has noticed that the sucker won't compile - there was no task_struct::io_usage. At which point the ac_io calculation had changed from encode_comp_t(current->io_usage) to encode_comp_t(0) and the bug in the next line (absolutely real back then, had it ever managed to compile) become a harmless bogosity. Looks like nobody has ever noticed until now. Anyway, let's bury that idiocy now that it got noticed. 17 years is long enough... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* sched: Make task->start_time nanoseconds basedThomas Gleixner2014-07-231-7/+3
| | | | | | | Simplify the timespec to nsec/usec conversions. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: John Stultz <john.stultz@linaro.org>
* acct: Use ktime_get_ts()Thomas Gleixner2014-06-121-1/+1
| | | | | | | | | | | do_posix_clock_monotonic_gettime() is a leftover from the initial posix timer implementation which maps to ktime_get_ts() Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: John Stultz <john.stultz@linaro.org> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/20140611234606.764810535@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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