- 20 Jan, 2022 40 commits
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Marco Elver authored
Until recent versions of GCC and Clang, it was not possible to disable KCOV instrumentation via a function attribute. The relevant function attribute was introduced in 540540d0 ("kcov: add __no_sanitize_coverage to fix noinstr for all architectures"). x86 was the first architecture to want a working noinstr, and at the time no compiler support for the attribute existed yet. Therefore, commit 0f1441b4 ("objtool: Fix noinstr vs KCOV") introduced the ability to NOP __sanitizer_cov_*() calls in .noinstr.text. However, this doesn't work for other architectures like arm64 and s390 that want a working noinstr per ARCH_WANTS_NO_INSTR. At the time of 0f1441b4, we didn't yet have ARCH_WANTS_NO_INSTR, but now we can move the Kconfig dependency checks to the generic KCOV option. KCOV will be available if: - architecture does not care about noinstr, OR - we have objtool support (like on x86), OR - GCC is 12.0 or newer, OR - Clang is 13.0 or newer. Link: https://lkml.kernel.org/r/20211201152604.3984495-1-elver@google.comSigned-off-by:
Marco Elver <elver@google.com> Reviewed-by:
Nathan Chancellor <nathan@kernel.org> Acked-by:
Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Nick Desaulniers <ndesaulniers@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Andrey Konovalov <andreyknvl@gmail.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will@kernel.org> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Nathan Chancellor authored
Commit b05fbcc3 ("btrfs: disable build on platforms having page size 256K") disabled btrfs for configurations that used a 256kB page size. However, it did not fully solve the problem because CONFIG_TEST_KMOD selects CONFIG_BTRFS, which does not account for the dependency. This results in a Kconfig warning and the failed BUILD_BUG_ON error returning. WARNING: unmet direct dependencies detected for BTRFS_FS Depends on [n]: BLOCK [=y] && !PPC_256K_PAGES && !PAGE_SIZE_256KB [=y] Selected by [m]: - TEST_KMOD [=m] && RUNTIME_TESTING_MENU [=y] && m && MODULES [=y] && NETDEVICES [=y] && NET_CORE [=y] && INET [=y] && BLOCK [=y] To resolve this, add CONFIG_PAGE_SIZE_LESS_THAN_256KB as a dependency of CONFIG_TEST_KMOD so there is no more invalid configuration or build errors. Link: https://lkml.kernel.org/r/20211129230141.228085-4-nathan@kernel.org Fixes: b05fbcc3 ("btrfs: disable build on platforms having page size 256K") Signed-off-by:
kernel test robot <lkp@intel.com> Cc: Chris Mason <clm@fb.com> Cc: David Sterba <dsterba@suse.com> Cc: Josef Bacik <josef@toxicpanda.com> Cc: Luis Chamberlain <mcgrof@kernel.org> Cc: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by:
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Nathan Chancellor authored
Use the newly introduced CONFIG_PAGE_SIZE_LESS_THAN_256KB to describe the dependency introduced by commit b05fbcc3 ("btrfs: disable build on platforms having page size 256K"). Link: https://lkml.kernel.org/r/20211129230141.228085-3-nathan@kernel.orgSigned-off-by:
David Sterba <dsterba@suse.com> Cc: Chris Mason <clm@fb.com> Cc: Josef Bacik <josef@toxicpanda.com> Cc: kernel test robot <lkp@intel.com> Cc: Luis Chamberlain <mcgrof@kernel.org> Cc: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by:
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Nathan Chancellor authored
Patch series "Fix CONFIG_TEST_KMOD with 256kB page size". The kernel test robot reported a build error [1] from a failed assertion in fs/btrfs/inode.c with a hexagon randconfig that includes CONFIG_PAGE_SIZE_256KB. This error is the same one that was addressed by commit b05fbcc3 ("btrfs: disable build on platforms having page size 256K") but CONFIG_TEST_KMOD selects CONFIG_BTRFS without having the "page size less than 256kB dependency", which results in the error reappearing. The first patch introduces CONFIG_PAGE_SIZE_LESS_THAN_256KB by splitting it off from CONFIG_PAGE_SIZE_LESS_THAN_64KB, which was introduced in commit 1f0e290c ("arch: Add generic Kconfig option indicating page size smaller than 64k") for a similar reason in 5.16-rc3. The second patch uses that configuration option for CONFIG_BTRFS to reduce duplication. The third patch resolves the build error by adding CONFIG_PAGE_SIZE_LESS_THAN_256KB as a dependency to CONFIG_TEST_KMOD so that CONFIG_BTRFS does not get enabled under that invalid configuration. [1]: https://lore.kernel.org/r/202111270255.UYOoN5VN-lkp@intel.com/ This patch (of 3): btrfs requires a page size smaller than 256kB. To use that dependency in other places, introduce CONFIG_PAGE_SIZE_LESS_THAN_256KB and reuse that dependency in CONFIG_PAGE_SIZE_LESS_THAN_64KB. Link: https://lkml.kernel.org/r/20211129230141.228085-1-nathan@kernel.org Link: https://lkml.kernel.org/r/20211129230141.228085-2-nathan@kernel.orgSigned-off-by:
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Qian Cai authored
Some general debugging features like kmemleak, KASAN, lockdep, UBSAN etc help fix many viruses like a microscope. On the other hand, those features are scatter around and mixed up with more situational debugging options making them difficult to consume properly. This cold help amplify the general debugging/testing efforts and help establish sensitive default values for those options across the broad. This could also help different distros to collaborate on maintaining debug-flavored kernels. The config is based on years' experiences running daily CI inside the largest enterprise Linux distro company to seek regressions on linux-next builds on different bare-metal and virtual platforms. It can be used for example, $ make ARCH=arm64 defconfig debug.config Since KASAN and KCSAN can't be enabled together, we will need to create a separate one for KCSAN later as well. Link: https://lkml.kernel.org/r/20211115134754.7334-1-quic_qiancai@quicinc.comSigned-off-by:
Qian Cai <quic_qiancai@quicinc.com> Acked-by:
Paul E. McKenney <paulmck@kernel.org> Cc: Marco Elver <elver@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Daniel Thompson <daniel.thompson@linaro.org> Cc: Masahiro Yamada <masahiroy@kernel.org> Cc: Naresh Kamboju <naresh.kamboju@linaro.org> Cc: "Stephen Rothwell" <sfr@canb.auug.org.au> Cc: Randy Dunlap <rdunlap@infradead.org> Signed-off-by:
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wangyong authored
Delay accounting does not track the delay of memory compact. When there is not enough free memory, tasks can spend a amount of their time waiting for compact. To get the impact of tasks in direct memory compact, measure the delay when allocating memory through memory compact. Also update tools/accounting/getdelays.c: / # ./getdelays_next -di -p 304 print delayacct stats ON printing IO accounting PID 304 CPU count real total virtual total delay total delay average 277 780000000 849039485 18877296 0.068ms IO count delay total delay average 0 0 0ms SWAP count delay total delay average 0 0 0ms RECLAIM count delay total delay average 5 11088812685 2217ms THRASHING count delay total delay average 0 0 0ms COMPACT count delay total delay average 3 72758 0ms watch: read=0, write=0, cancelled_write=0 Link: https://lkml.kernel.org/r/1638619795-71451-1-git-send-email-wang.yong12@zte.com.cnSigned-off-by:wangyong <wang.yong12@zte.com.cn> Reviewed-by:
Jiang Xuexin <jiang.xuexin@zte.com.cn> Reviewed-by:
Zhang Wenya <zhang.wenya1@zte.com.cn> Reviewed-by:
Yang Yang <yang.yang29@zte.com.cn> Reviewed-by:
Balbir Singh <bsingharora@gmail.com> Signed-off-by:
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wangyong authored
Add thrashing page cache and direct compact related descriptions and update the usage of getdelays userspace utility. The following patches modifications have been updated: https://lore.kernel.org/all/20190312102002.31737-4-jinpuwang@gmail.com/ https://lore.kernel.org/all/1638619795-71451-1-git-send-email- wang.yong12@zte.com.cn/ Link: https://lkml.kernel.org/r/1639583021-92977-1-git-send-email-wang.yong12@zte.com.cnSigned-off-by:
Zeal Robot <zealci@zte.com.cn> Cc: Balbir Singh <bsingharora@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@kernel.org> Signed-off-by:
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Yang Yang authored
Flags in struct task_delay_info is used to distinguish the difference between swapin and blkio delay acountings. But after patch "delayacct: support swapin delay accounting for swapping without blkio", there is no need to do that since swapin and blkio delay accounting use their own functions. Link: https://lkml.kernel.org/r/20211124065958.36703-1-yang.yang29@zte.com.cnSigned-off-by:
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Yang Yang authored
When a task is created after delayacct is enabled, kernel will do all the delay accountings for that task. The problems is if user disables delayacct by set /proc/sys/kernel/task_delayacct to zero, only blkio delay accounting is disabled. Now disable all the kinds of delay accountings when /proc/sys/kernel/task_delayacct sets to zero. Link: https://lkml.kernel.org/r/20211123140342.32962-1-ran.xiaokai@zte.com.cnSigned-off-by:
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Yang Yang authored
Currently delayacct accounts swapin delay only for swapping that cause blkio. If we use zram for swapping, tools/accounting/getdelays can't get any SWAP delay. It's useful to get zram swapin delay information, for example to adjust compress algorithm or /proc/sys/vm/swappiness. Reference to PSI, it accounts any kind of swapping by doing its work in swap_readpage(), no matter whether swapping causes blkio. Let delayacct do the similar work. Link: https://lkml.kernel.org/r/20211112083813.8559-1-yang.yang29@zte.com.cnSigned-off-by:
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Sebastian Andrzej Siewior authored
The oops id has been added as part of the end of trace marker for the kerneloops.org project. The id is used to automatically identify duplicate submissions of the same report. Identical looking reports with different a id can be considered as the same oops occurred again. The early initialisation of the oops_id can create a warning if the random core is not yet fully initialized. On PREEMPT_RT it is problematic if the id is initialized on demand from non preemptible context. The kernel oops project is not available since 2017. Remove the oops_id and use 0 in the output in case parser rely on it. Link: https://bugs.debian.org/953172 Link: https://lkml.kernel.org/r/Ybdi16aP2NEugWHq@linutronix.deSigned-off-by:
Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by:
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Marco Elver authored
Introduce the error detector "warning" to the error_report event and use the error_report_end tracepoint at the end of a warning report. This allows in-kernel tests but also userspace to more easily determine if a warning occurred without polling kernel logs. [akpm@linux-foundation.org: add comma to enum list, per Andy] Link: https://lkml.kernel.org/r/20211115085630.1756817-1-elver@google.comSigned-off-by:
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Minghao Chi authored
Return value directly instead of taking this in a variable. Link: https://lkml.kernel.org/r/20211210023211.424609-1-chi.minghao@zte.com.cnSigned-off-by:
Minghao Chi <chi.minghao@zte.com.cn> Reported-by:
Zeal Robot <zealci@zte.com.cm> Cc: Christian Brauner <christian.brauner@ubuntu.com> Cc: Jan Kara <jack@suse.cz> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by:
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NeilBrown authored
congestion_wait() in this context is just a sleep - block devices do not support congestion signalling any more. The goal for this wait, which was introduced in commit ae78bf9c ("[PATCH] add -o flush for fat") is to wait for any recently written data to get to storage. We currently have no direct mechanism to do this, so a simple wait that behaves identically to the current congestion_wait() is the best we can do. This is a step towards removing congestion_wait() Link: https://lkml.kernel.org/r/163936544519.22433.13400436295732112065@noble.neil.brown.nameSigned-off-by:
NeilBrown <neilb@suse.de> Acked-by:
OGAWA Hirofumi <hirofumi@mail.parknet.co.jp> Signed-off-by:
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Kees Cook authored
In preparation for FORTIFY_SOURCE performing compile-time and run-time field bounds checking for memset(), avoid intentionally writing across neighboring fields. Add struct_group() to mark the "info" region (containing struct DInfo and struct DXInfo structs) in struct hfsplus_cat_folder and struct hfsplus_cat_file that are written into directly, so the compiler can correctly reason about the expected size of the writes. "pahole" shows no size nor member offset changes to struct hfsplus_cat_folder nor struct hfsplus_cat_file. "objdump -d" shows no object code changes. Link: https://lkml.kernel.org/r/20211119192851.1046717-1-keescook@chromium.orgSigned-off-by:
Kees Cook <keescook@chromium.org> Acked-by:
Christian Brauner <christian.brauner@ubuntu.com> Cc: Zhen Lei <thunder.leizhen@huawei.com> Signed-off-by:
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Colin Ian King authored
Pointer sbufs is being assigned a value but it's not being used later on. The pointer is redundant and can be removed. Cleans up scan-build static analysis warning: fs/nilfs2/page.c:203:8: warning: Although the value stored to 'sbufs' is used in the enclosing expression, the value is never actually read from 'sbufs' [deadcode.DeadStores] sbh = sbufs = page_buffers(src); Link: https://lkml.kernel.org/r/20211211180955.550380-1-colin.i.king@gmail.com Link: https://lkml.kernel.org/r/1640712476-15136-1-git-send-email-konishi.ryusuke@gmail.comSigned-off-by:Colin Ian King <colin.i.king@gmail.com> Signed-off-by:
Ryusuke Konishi <konishi.ryusuke@gmail.com> Signed-off-by:
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H.J. Lu authored
Extend commit ce81bb25 ("fs/binfmt_elf: use PT_LOAD p_align values for suitable start address") which fixed PIE binaries built with -Wl,-z,max-page-size=0x200000, to cover static PIE binaries. This fixes: https://bugzilla.kernel.org/show_bug.cgi?id=215275 Tested by verifying static PIE binaries with -Wl,-z,max-page-size=0x200000 loading. Link: https://lkml.kernel.org/r/20211209174052.370537-1-hjl.tools@gmail.comSigned-off-by:
H.J. Lu <hjl.tools@gmail.com> Cc: Chris Kennelly <ckennelly@google.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Song Liu <songliubraving@fb.com> Cc: David Rientjes <rientjes@google.com> Cc: Ian Rogers <irogers@google.com> Cc: Hugh Dickins <hughd@google.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Sandeep Patil <sspatil@google.com> Cc: Fangrui Song <maskray@google.com> Cc: Nick Desaulniers <ndesaulniers@google.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Shuah Khan <shuah@kernel.org> Signed-off-by:
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Rikard Falkeborn authored
Add commonly used structs (>50 instances) which are always or almost always const. Link: https://lkml.kernel.org/r/20211127101134.33101-1-rikard.falkeborn@gmail.comSigned-off-by:
Rikard Falkeborn <rikard.falkeborn@gmail.com> Cc: Joe Perches <joe@perches.com> Signed-off-by:
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Joe Perches authored
The Kconfig help test erroneously counts patch context lines as part of the help text. Fix that and improve the message block output. Link: https://lkml.kernel.org/r/06c0cdc157ae1502e8e9eb3624b9ea995cf11e7a.camel@perches.comSigned-off-by:
Joe Perches <joe@perches.com> Tested-by:
Randy Dunlap <rdunlap@infradead.org> Acked-by:
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Jerome Forissier authored
One exceptions to the COMMIT_LOG_LONG_LINE rule is a file path followed by ':'. That is typically some sort diagnostic message from a compiler or a build tool, in which case we don't want to wrap the lines but keep the message unmodified. The regular expression used to match this pattern currently doesn't accept absolute paths or + characters. This can result in false positives as in the following (out-of-tree) example: ... /home/jerome/work/optee_repo_qemu/build/../toolchains/aarch32/bin/arm-linux-gnueabihf-ld.bfd: /home/jerome/work/toolchains-gcc10.2/aarch32/bin/../lib/gcc/arm-none-linux-gnueabihf/10.2.1/../../../../arm-none-linux-gnueabihf/lib/libstdc++.a(eh_alloc.o): in function `__cxa_allocate_exception': /tmp/dgboter/bbs/build03--cen7x86_64/buildbot/cen7x86_64--arm-none-linux-gnueabihf/build/src/gcc/libstdc++-v3/libsupc++/eh_alloc.cc:284: undefined reference to `malloc' ... Update the regular expression to match the above paths. Link: https://lkml.kernel.org/r/20210923143842.2837983-1-jerome@forissier.orgSigned-off-by:
Jerome Forissier <jerome@forissier.org> Acked-by:
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Andrey Konovalov authored
Make do_kmem_cache_size_bulk() destroy the cache it creates. Link: https://lkml.kernel.org/r/aced20a94bf04159a139f0846e41d38a1537debb.1640018297.git.andreyknvl@google.com Fixes: 03a9349a ("lib/test_meminit: add a kmem_cache_alloc_bulk() test") Signed-off-by:
Andrey Konovalov <andreyknvl@google.com> Reviewed-by:
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Andy Shevchenko authored
Remove licence boilerplate text from the UAPI header. Link: https://lkml.kernel.org/r/20211216113552.81199-2-andriy.shevchenko@linux.intel.comSigned-off-by:
Andy Shevchenko <andriy.shevchenko@linux.intel.com> Acked-by:
Christoph Hellwig <hch@lst.de> Signed-off-by:
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Andy Shevchenko authored
Discourage people from using UAPI header in new code by adding a note. Link: https://lkml.kernel.org/r/20211216113552.81199-1-andriy.shevchenko@linux.intel.comSigned-off-by:
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Andy Shevchenko authored
When kernel.h is used in the headers it adds a lot into dependency hell, especially when there are circular dependencies are involved. Replace kernel.h inclusion with the list of what is really being used. Link: https://lkml.kernel.org/r/20211213204441.56204-1-andriy.shevchenko@linux.intel.comSigned-off-by:
Brendan Higgins <brendanhiggins@google.com> Tested-by:
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Isabella Basso authored
Use KUnit framework to make tests more easily integrable with CIs. Even though these tests are not yet properly written as unit tests this change should help in debugging. Also remove kernel messages (i.e. through pr_info) as KUnit handles all debugging output and let it handle module init and exit details. Link: https://lkml.kernel.org/r/20211208183711.390454-6-isabbasso@riseup.netReviewed-by:
David Gow <davidgow@google.com> Reported-by:
Augusto Durães Camargo <augusto.duraes33@gmail.com> Signed-off-by:
Enzo Ferreira <ferreiraenzoa@gmail.com> Signed-off-by:
Isabella Basso <isabbasso@riseup.net> Cc: Brendan Higgins <brendanhiggins@google.com> Cc: Daniel Latypov <dlatypov@google.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Rodrigo Siqueira <rodrigosiqueiramelo@gmail.com> Cc: Shuah Khan <skhan@linuxfoundation.org> Signed-off-by:
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Isabella Basso authored
Split TEST_HASH so that each entry only has one file. Note that there's no stringhash test file, but actually <linux/stringhash.h> tests are performed in lib/test_hash.c. Link: https://lkml.kernel.org/r/20211208183711.390454-5-isabbasso@riseup.netReviewed-by:
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Isabella Basso authored
Split up test_hash_init so that it calls each test more explicitly insofar it is possible without rewriting the entire file. This aims at improving readability. Split tests performed on string_or as they don't interfere with those performed in hash_or. Also separate pr_info calls about skipped tests as they're not part of the tests themselves, but only warn about (un)defined arch-specific hash functions. Link: https://lkml.kernel.org/r/20211208183711.390454-4-isabbasso@riseup.netReviewed-by:
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Isabella Basso authored
Split the test_int_hash function to keep its mainloop separate from arch-specific chunks, which are only compiled as needed. This aims at improving readability. Link: https://lkml.kernel.org/r/20211208183711.390454-3-isabbasso@riseup.netReviewed-by:
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Isabella Basso authored
Patch series "test_hash.c: refactor into KUnit", v3. We refactored the lib/test_hash.c file into KUnit as part of the student group LKCAMP [1] introductory hackathon for kernel development. This test was pointed to our group by Daniel Latypov [2], so its full conversion into a pure KUnit test was our goal in this patch series, but we ran into many problems relating to it not being split as unit tests, which complicated matters a bit, as the reasoning behind the original tests is quite cryptic for those unfamiliar with hash implementations. Some interesting developments we'd like to highlight are: - In patch 1/5 we noticed that there was an unused define directive that could be removed. - In patch 4/5 we noticed how stringhash and hash tests are all under the lib/test_hash.c file, which might cause some confusion, and we also broke those kernel config entries up. Overall KUnit developments have been made in the other patches in this series: In patches 2/5, 3/5 and 5/5 we refactored the lib/test_hash.c file so as to make it more compatible with the KUnit style, whilst preserving the original idea of the maintainer who designed it (i.e. George Spelvin), which might be undesirable for unit tests, but we assume it is enough for a first patch. This patch (of 5): Currently, there exist hash_32() and __hash_32() functions, which were introduced in a patch [1] targeting architecture specific optimizations. These functions can be overridden on a per-architecture basis to achieve such optimizations. They must set their corresponding define directive (HAVE_ARCH_HASH_32 and HAVE_ARCH__HASH_32, respectively) so that header files can deal with these overrides properly. As the supported 32-bit architectures that have their own hash function implementation (i.e. m68k, Microblaze, H8/300, pa-risc) have only been making use of the (more general) __hash_32() function (which only lacks a right shift operation when compared to the hash_32() function), remove the define directive corresponding to the arch-specific hash_32() implementation. [1] https://lore.kernel.org/lkml/20160525073311.5600.qmail@ns.sciencehorizons.net/ [akpm@linux-foundation.org: hash_32_generic() becomes hash_32()] Link: https://lkml.kernel.org/r/20211208183711.390454-1-isabbasso@riseup.net Link: https://lkml.kernel.org/r/20211208183711.390454-2-isabbasso@riseup.netReviewed-by:
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Zhen Lei authored
Currently, the entry->prev and entry->next are considered to be valid as long as they are not LIST_POISON{1|2}. However, the memory may be corrupted. The prev->next is invalid probably because 'prev' is invalid, not because prev->next's content is illegal. Unfortunately, the printk and its subfunctions will modify the registers that hold the 'prev' and 'next', and we don't see this valuable information in the BUG context. So print the contents of 'entry->prev' and 'entry->next'. Here's an example: list_del corruption. prev->next should be c0ecbf74, but was c08410dc kernel BUG at lib/list_debug.c:53! ... ... PC is at __list_del_entry_valid+0x58/0x98 LR is at __list_del_entry_valid+0x58/0x98 psr: 60000093 sp : c0ecbf30 ip : 00000000 fp : 00000001 r10: c08410d0 r9 : 00000001 r8 : c0825e0c r7 : 20000013 r6 : c08410d0 r5 : c0ecbf74 r4 : c0ecbf74 r3 : c0825d08 r2 : 00000000 r1 : df7ce6f4 r0 : 00000044 ... ... Stack: (0xc0ecbf30 to 0xc0ecc000) bf20: c0ecbf74 c0164fd0 c0ecbf70 c0165170 bf40: c0eca000 c0840c00 c0840c00 c0824500 c0825e0c c0189bbc c088f404 60000013 bf60: 60000013 c0e85100 000004ec 00000000 c0ebcdc0 c0ecbf74 c0ecbf74 c0825d08 bf80: c0e807c0 c018965c 00000000 c013f2a0 c0e807c0 c013f154 00000000 00000000 bfa0: 00000000 00000000 00000000 c01001b0 00000000 00000000 00000000 00000000 bfc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 bfe0: 00000000 00000000 00000000 00000000 00000013 00000000 00000000 00000000 (__list_del_entry_valid) from (__list_del_entry+0xc/0x20) (__list_del_entry) from (finish_swait+0x60/0x7c) (finish_swait) from (rcu_gp_kthread+0x560/0xa20) (rcu_gp_kthread) from (kthread+0x14c/0x15c) (kthread) from (ret_from_fork+0x14/0x24) At first, I thought prev->next was overwritten. Later, I carefully analyzed the RCU code and the disassembly code. The error occurred when deleting a node from the list rcu_state.gp_wq. The System.map shows that the address of rcu_state is c0840c00. Then I use gdb to obtain the offset of rcu_state.gp_wq.task_list. (gdb) p &((struct rcu_state *)0)->gp_wq.task_list $1 = (struct list_head *) 0x4dc Again: list_del corruption. prev->next should be c0ecbf74, but was c08410dc c08410dc = c0840c00 + 0x4dc = &rcu_state.gp_wq.task_list Because rcu_state.gp_wq has at most one node, so I can guess that "prev = &rcu_state.gp_wq.task_list". But for other scenes, maybe I wasn't so lucky, I cannot figure out the value of 'prev'. Link: https://lkml.kernel.org/r/20211207025835.1909-1-thunder.leizhen@huawei.comSigned-off-by:Zhen Lei <thunder.leizhen@huawei.com> Cc: "Paul E . McKenney" <paulmck@linux.vnet.ibm.com> Signed-off-by:
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Andy Shevchenko authored
Introduce list_is_head() in the similar (*) way as it's done for list_entry_is_head(). Make use of it in the list.h. *) it's done as inliner and not a macro to be aligned with other list_is_*() APIs; while at it, make all three to have the same style. Link: https://lkml.kernel.org/r/20211201141824.81400-1-andriy.shevchenko@linux.intel.comSigned-off-by:
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Alexey Dobriyan authored
I've made a mistake of looking into lib/kstrtox.o code generation. The only function remotely performance critical is _parse_integer() (via /proc/*/map_files/*), everything else is not. Uninline everything, shrink lib/kstrtox.o by ~20 % ! Space savings on x86_64: add/remove: 0/0 grow/shrink: 0/23 up/down: 0/-1269 (-1269 !!!) Function old new delta kstrtoull 16 13 -3 kstrtouint 59 48 -11 kstrtou8 60 49 -11 kstrtou16 61 50 -11 _kstrtoul 46 35 -11 kstrtoull_from_user 95 83 -12 kstrtoul_from_user 95 83 -12 kstrtoll 93 80 -13 kstrtouint_from_user 124 83 -41 kstrtou8_from_user 125 83 -42 kstrtou16_from_user 126 83 -43 kstrtos8 101 50 -51 kstrtos16 102 51 -51 kstrtoint 100 49 -51 _kstrtol 93 35 -58 kstrtobool_from_user 156 75 -81 kstrtoll_from_user 165 83 -82 kstrtol_from_user 165 83 -82 kstrtoint_from_user 172 83 -89 kstrtos8_from_user 173 83 -90 kstrtos16_from_user 174 83 -91 _parse_integer 136 10 -126 _kstrtoull 308 101 -207 Total: Before=3421236, After=3419967, chg -0.04% Link: https://lkml.kernel.org/r/YZDsFDhHst4m2Pnt@localhost.localdomainSigned-off-by:
Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by:
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Randy Dunlap authored
When --nogit is used with scripts/get_maintainer.pl, the script spews 4 lines of unnecessary information (noise). Do not print those lines when --nogit is specified. This change removes the printing of these 4 lines: ./scripts/get_maintainer.pl: No supported VCS found. Add --nogit to options? Using a git repository produces better results. Try Linus Torvalds' latest git repository using: git clone git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git Link: https://lkml.kernel.org/r/20220102031424.3328-1-rdunlap@infradead.orgSigned-off-by:
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Davidlohr Bueso authored
PRIO_PGRP needs the tasklist_lock mainly to serialize vs setpgid(2), to protect against any concurrent change_pid(PIDTYPE_PGID) that can move the task from one hlist to another while iterating. However, the remaining can only rely only on RCU: PRIO_PROCESS only does the task lookup and never iterates over tasklist and we already have an rcu-aware stable pointer. PRIO_USER is already racy vs setuid(2) so with creds being rcu protected, we can end up seeing stale data. When removing the tasklist_lock there can be a race with (i) fork but this is benign as the child's nice is inherited and the new task is not observable by the user yet either, hence the return semantics do not differ. And (ii) a race with exit, which is a small window and can cause us to miss a task which was removed from the list and it had the highest nice. Similarly change the buggy do_each_thread/while_each_thread combo in PRIO_USER for the rcu-safe for_each_process_thread flavor, which doesn't make use of next_thread/p->thread_group. [akpm@linux-foundation.org: coding style fixes] Link: https://lkml.kernel.org/r/20211210182250.43734-1-dave@stgolabs.netSigned-off-by:
Davidlohr Bueso <dbueso@suse.de> Acked-by:
Oleg Nesterov <oleg@redhat.com> Signed-off-by:
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Yafang Shao authored
When I was implementing a new per-cpu kthread cfs_migration, I found the comm of it "cfs_migration/%u" is truncated due to the limitation of TASK_COMM_LEN. For example, the comm of the percpu thread on CPU10~19 all have the same name "cfs_migration/1", which will confuse the user. This issue is not critical, because we can get the corresponding CPU from the task's Cpus_allowed. But for kthreads corresponding to other hardware devices, it is not easy to get the detailed device info from task comm, for example, jbd2/nvme0n1p2- xfs-reclaim/sdf Currently there are so many truncated kthreads: rcu_tasks_kthre rcu_tasks_rude_ rcu_tasks_trace poll_mpt3sas0_s ext4-rsv-conver xfs-reclaim/sd{a, b, c, ...} xfs-blockgc/sd{a, b, c, ...} xfs-inodegc/sd{a, b, c, ...} audit_send_repl ecryptfs-kthrea vfio-irqfd-clea jbd2/nvme0n1p2- ... We can shorten these names to work around this problem, but it may be not applied to all of the truncated kthreads. Take 'jbd2/nvme0n1p2-' for example, it is a nice name, and it is not a good idea to shorten it. One possible way to fix this issue is extending the task comm size, but as task->comm is used in lots of places, that may cause some potential buffer overflows. Another more conservative approach is introducing a new pointer to store kthread's full name if it is truncated, which won't introduce too much overhead as it is in the non-critical path. Finally we make a dicision to use the second approach. See also the discussions in this thread: https://lore.kernel.org/lkml/20211101060419.4682-1-laoar.shao@gmail.com/ After this change, the full name of these truncated kthreads will be displayed via /proc/[pid]/comm: rcu_tasks_kthread rcu_tasks_rude_kthread rcu_tasks_trace_kthread poll_mpt3sas0_statu ext4-rsv-conversion xfs-reclaim/sdf1 xfs-blockgc/sdf1 xfs-inodegc/sdf1 audit_send_reply ecryptfs-kthread vfio-irqfd-cleanup jbd2/nvme0n1p2-8 Link: https://lkml.kernel.org/r/20211120112850.46047-1-laoar.shao@gmail.comSigned-off-by:Yafang Shao <laoar.shao@gmail.com> Reviewed-by:
David Hildenbrand <david@redhat.com> Reviewed-by:
Petr Mladek <pmladek@suse.com> Suggested-by:
Steven Rostedt <rostedt@goodmis.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Arnaldo Carvalho de Melo <arnaldo.melo@gmail.com> Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com> Cc: Andrii Nakryiko <andrii.nakryiko@gmail.com> Cc: Michal Miroslaw <mirq-linux@rere.qmqm.pl> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Matthew Wilcox <willy@infradead.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Kees Cook <keescook@chromium.org> Signed-off-by:
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Yafang Shao authored
As the sched:sched_switch tracepoint args are derived from the kernel, we'd better make it same with the kernel. So the macro TASK_COMM_LEN is converted to type enum, then all the BPF programs can get it through BTF. The BPF program which wants to use TASK_COMM_LEN should include the header vmlinux.h. Regarding the test_stacktrace_map and test_tracepoint, as the type defined in linux/bpf.h are also defined in vmlinux.h, so we don't need to include linux/bpf.h again. Link: https://lkml.kernel.org/r/20211120112738.45980-8-laoar.shao@gmail.comSigned-off-by:
Andrii Nakryiko <andrii@kernel.org> Acked-by:
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Yafang Shao authored
tools/bpf/bpftool/skeleton: replace bpf_probe_read_kernel with bpf_probe_read_kernel_str to get task comm bpf_probe_read_kernel_str() will add a nul terminator to the dst, then we don't care about if the dst size is big enough. Link: https://lkml.kernel.org/r/20211120112738.45980-7-laoar.shao@gmail.comSigned-off-by:
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Yafang Shao authored
samples/bpf/test_overhead_kprobe_kern: replace bpf_probe_read_kernel with bpf_probe_read_kernel_str to get task comm bpf_probe_read_kernel_str() will add a nul terminator to the dst, then we don't care about if the dst size is big enough. This patch also replaces the hard-coded 16 with TASK_COMM_LEN to make it grepable. Link: https://lkml.kernel.org/r/20211120112738.45980-6-laoar.shao@gmail.comSigned-off-by:
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Yafang Shao authored
It is better to use get_task_comm() instead of the open coded string copy as we do in other places. struct elf_prpsinfo is used to dump the task information in userspace coredump or kernel vmcore. Below is the verification of vmcore, crash> ps PID PPID CPU TASK ST %MEM VSZ RSS COMM 0 0 0 ffffffff9d21a940 RU 0.0 0 0 [swapper/0] > 0 0 1 ffffa09e40f85e80 RU 0.0 0 0 [swapper/1] > 0 0 2 ffffa09e40f81f80 RU 0.0 0 0 [swapper/2] > 0 0 3 ffffa09e40f83f00 RU 0.0 0 0 [swapper/3] > 0 0 4 ffffa09e40f80000 RU 0.0 0 0 [swapper/4] > 0 0 5 ffffa09e40f89f80 RU 0.0 0 0 [swapper/5] 0 0 6 ffffa09e40f8bf00 RU 0.0 0 0 [swapper/6] > 0 0 7 ffffa09e40f88000 RU 0.0 0 0 [swapper/7] > 0 0 8 ffffa09e40f8de80 RU 0.0 0 0 [swapper/8] > 0 0 9 ffffa09e40f95e80 RU 0.0 0 0 [swapper/9] > 0 0 10 ffffa09e40f91f80 RU 0.0 0 0 [swapper/10] > 0 0 11 ffffa09e40f93f00 RU 0.0 0 0 [swapper/11] > 0 0 12 ffffa09e40f90000 RU 0.0 0 0 [swapper/12] > 0 0 13 ffffa09e40f9bf00 RU 0.0 0 0 [swapper/13] > 0 0 14 ffffa09e40f98000 RU 0.0 0 0 [swapper/14] > 0 0 15 ffffa09e40f9de80 RU 0.0 0 0 [swapper/15] It works well as expected. Some comments are added to explain why we use the hard-coded 16. Link: https://lkml.kernel.org/r/20211120112738.45980-5-laoar.shao@gmail.comSuggested-by: -
Yafang Shao authored
We'd better use the helper get_task_comm() rather than the open-coded strlcpy() to get task comm. As the comment above the hard-coded 16, we can replace it with TASK_COMM_LEN. Link: https://lkml.kernel.org/r/20211120112738.45980-4-laoar.shao@gmail.comSigned-off-by:
Dennis Dalessandro <dennis.dalessandro@cornelisnetworks.com> Reviewed-by:
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