- 09 Nov, 2021 40 commits
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Kefeng Wang authored
The is_kernel_inittext() and init_kernel_text() are with same functionality, let's just keep is_kernel_inittext() and move it into sections.h, then update all the callers. Link: https://lkml.kernel.org/r/20210930071143.63410-5-wangkefeng.wang@huawei.comSigned-off-by:
Kefeng Wang <wangkefeng.wang@huawei.com> Reviewed-by:
Sergey Senozhatsky <senozhatsky@chromium.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Alexander Potapenko <glider@google.com> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Andrey Konovalov <andreyknvl@gmail.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: "David S. Miller" <davem@davemloft.net> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: Matt Turner <mattst88@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Simek <monstr@monstr.eu> Cc: Paul Mackerras <paulus@samba.org> Cc: Petr Mladek <pmladek@suse.com> Cc: Richard Henderson <rth@twiddle.net> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Kefeng Wang authored
Move core_kernel_data() into sections.h and rename it to is_kernel_core_data(), also make it return bool value, then update all the callers. Link: https://lkml.kernel.org/r/20210930071143.63410-4-wangkefeng.wang@huawei.comSigned-off-by:
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Kefeng Wang authored
The is_kernel_inittext/is_kernel_text/is_kernel function should not include the end address(the labels _einittext, _etext and _end) when check the address range, the issue exists since Linux v2.6.12. Link: https://lkml.kernel.org/r/20210930071143.63410-3-wangkefeng.wang@huawei.comSigned-off-by:
Petr Mladek <pmladek@suse.com> Reviewed-by:
Steven Rostedt (VMware) <rostedt@goodmis.org> Acked-by:
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Kefeng Wang authored
Patch series "sections: Unify kernel sections range check and use", v4. There are three head files(kallsyms.h, kernel.h and sections.h) which include the kernel sections range check, let's make some cleanup and unify them. 1. cleanup arch specific text/data check and fix address boundary check in kallsyms.h 2. make all the basic/core kernel range check function into sections.h 3. update all the callers, and use the helper in sections.h to simplify the code After this series, we have 5 APIs about kernel sections range check in sections.h * is_kernel_rodata() --- already in sections.h * is_kernel_core_data() --- come from core_kernel_data() in kernel.h * is_kernel_inittext() --- come from kernel.h and kallsyms.h * __is_kernel_text() --- add new internal helper * __is_kernel() --- add new internal helper Note: For the last two helpers, people should not use directly, consider to use corresponding function in kallsyms.h. This patch (of 11): Remove arch specific text and data check after commit 4ba66a97 ("arch: remove blackfin port"), no need arch-specific text/data check. Link: https://lkml.kernel.org/r/20210930071143.63410-1-wangkefeng.wang@huawei.com Link: https://lkml.kernel.org/r/20210930071143.63410-2-wangkefeng.wang@huawei.comSigned-off-by: -
Alexey Dobriyan authored
"A -= B; A" is equivalent to "A -= B". Link: https://lkml.kernel.org/r/YVmcP256fRMqCwgK@localhost.localdomainSigned-off-by:
Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by:
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Kees Cook authored
Commit b212921b ("elf: don't use MAP_FIXED_NOREPLACE for elf executable mappings") reverted back to using MAP_FIXED to map ELF LOAD segments because it was found that the segments in some binaries overlap and can cause MAP_FIXED_NOREPLACE to fail. The original intent of MAP_FIXED_NOREPLACE in the ELF loader was to prevent the silent clobbering of an existing mapping (e.g. stack) by the ELF image, which could lead to exploitable conditions. Quoting commit 4ed28639 ("fs, elf: drop MAP_FIXED usage from elf_map"), which originally introduced the use of MAP_FIXED_NOREPLACE in the loader: Both load_elf_interp and load_elf_binary rely on elf_map to map segments [to a specific] address and they use MAP_FIXED to enforce that. This is however [a] dangerous thing prone to silent data corruption which can be even exploitable. ... Let's take CVE-2017-1000253 as an example ... we could end up mapping [the executable] over the existing stack ... The [stack layout] issue has been fixed since then ... So we should be safe and any [similar] attack should be impractical. On the other hand this is just too subtle [an] assumption ... it can break quite easily and [be] hard to spot. ... Address this [weakness] by changing MAP_FIXED to the newly added MAP_FIXED_NOREPLACE. This will mean that mmap will fail if there is an existing mapping clashing with the requested one [instead of silently] clobbering it. Then processing ET_DYN binaries the loader already calculates a total size for the image when the first segment is mapped, maps the entire image, and then unmaps the remainder before the remaining segments are then individually mapped. To avoid the earlier problems (legitimate overlapping LOAD segments specified in the ELF), apply the same logic to ET_EXEC binaries as well. For both ET_EXEC and ET_DYN+INTERP use MAP_FIXED_NOREPLACE for the initial total size mapping and then use MAP_FIXED to build the final (possibly legitimately overlapping) mappings. For ET_DYN w/out INTERP, continue to map at a system-selected address in the mmap region. Link: https://lkml.kernel.org/r/20210916215947.3993776-1-keescook@chromium.org Link: https://lore.kernel.org/lkml/1595869887-23307-2-git-send-email-anthony.yznaga@oracle.comCo-developed-by:
Anthony Yznaga <anthony.yznaga@oracle.com> Signed-off-by:
Kees Cook <keescook@chromium.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Michal Hocko <mhocko@suse.com> Cc: Eric Biederman <ebiederm@xmission.com> Cc: Chen Jingwen <chenjingwen6@huawei.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Andrei Vagin <avagin@openvz.org> Cc: Khalid Aziz <khalid.aziz@oracle.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by:
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Peter Ujfalusi authored
The standard location of dictionary.txt is under codespell's package, on my machine atm (codespell 2.1, Artix Linux): /usr/lib/python3.9/site-packages/codespell_lib/data/dictionary.txt Since we enable the codespell by default for SOF I have constant: No codespell typos will be found - file '/usr/share/codespell/dictionary.txt': No such file or directory The patch proposes to try to fix up the path following the recommendation found here: https://github.com/codespell-project/codespell/issues/1540 Link: https://lkml.kernel.org/r/29e25d1364c8ad7f7657cc0660f60c568074d438.camel@perches.comSigned-off-by:
Peter Ujfalusi <peter.ujfalusi@linux.intel.com> Acked-by:
Joe Perches <joe@perches.com> Signed-off-by:
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Joe Perches authored
The EXPORT_SYMBOL test expects a single argument but definitions of EXPORT_SYMBOL_NS have multiple arguments. Update the test to extract only the first argument from any EXPORT_SYMBOL related definition. Link: https://lkml.kernel.org/r/9e8f251b42e405f460f26a23ba9b33ef45a94adc.camel@perches.comSigned-off-by:
Ian Pilcher <arequipeno@gmail.com> Cc: Dwaipayan Ray <dwaipayanray1@gmail.com> Cc: Lukas Bulwahn <lukas.bulwahn@gmail.com> Signed-off-by:
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Rikard Falkeborn authored
Add a couple of commonly used (>50 instances) sound ops structs that are typically const. Link: https://lkml.kernel.org/r/20210922211042.38017-1-rikard.falkeborn@gmail.comSigned-off-by:
Rikard Falkeborn <rikard.falkeborn@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Liam Girdwood <lgirdwood@gmail.com> Cc: Mark Brown <broonie@kernel.org> Cc: Jaroslav Kysela <perex@perex.cz> Cc: Takashi Iwai <tiwai@suse.com> Signed-off-by:
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Thomas Gleixner authored
sg_miter_stop() checks for disabled preemption before unmapping a page via kunmap_atomic(). The kernel doc mentions under context that preemption must be disabled if SG_MITER_ATOMIC is set. There is no active requirement for the caller to have preemption disabled before invoking sg_mitter_stop(). The sg_mitter_*() implementation itself has no such requirement. In fact, preemption is disabled by kmap_atomic() as part of sg_miter_next() and remains disabled as long as there is an active SG_MITER_ATOMIC mapping. This is a consequence of kmap_atomic() and not a requirement for sg_mitter_*() itself. The user chooses SG_MITER_ATOMIC because it uses the API in a context where blocking is not possible or blocking is possible but he chooses a lower weight mapping which is not available on all CPUs and so it might need less overhead to setup at a price that now preemption will be disabled. The kmap_atomic() implementation on PREEMPT_RT does not disable preemption. It simply disables CPU migration to ensure that the task remains on the same CPU while the caller remains preemptible. This in turn triggers the warning in sg_miter_stop() because preemption is allowed. The PREEMPT_RT and !PREEMPT_RT implementation of kmap_atomic() disable pagefaults as a requirement. It is sufficient to check for this instead of disabled preemption. Check for disabled pagefault handler in the SG_MITER_ATOMIC case. Remove the "preemption disabled" part from the kernel doc as the sg_milter*() implementation does not care. [bigeasy@linutronix.de: commit description] Link: https://lkml.kernel.org/r/20211015211409.cqopacv3pxdwn2ty@linutronix.deSigned-off-by:
Thomas Gleixner <tglx@linutronix.de> Signed-off-by:
Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by:
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Alexey Dobriyan authored
Codegen become bloated again after simple_strntoull() introduction add/remove: 0/0 grow/shrink: 0/4 up/down: 0/-224 (-224) Function old new delta simple_strtoul 5 2 -3 simple_strtol 23 20 -3 simple_strtoull 119 15 -104 simple_strtoll 155 41 -114 Link: https://lkml.kernel.org/r/YVmlB9yY4lvbNKYt@localhost.localdomainSigned-off-by:
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Lucas De Marchi authored
linux/string_helpers.h uses strlen(), so include the correponding header. Otherwise we get a compilation error if it's not also included by whoever included the helper. Link: https://lkml.kernel.org/r/20211005212634.3223113-1-lucas.demarchi@intel.comSigned-off-by:
Lucas De Marchi <lucas.demarchi@intel.com> Signed-off-by:
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Imran Khan authored
To print stack entries into a buffer, users of stackdepot, first get a list of stack entries using stack_depot_fetch and then print this list into a buffer using stack_trace_snprint. Provide a helper in stackdepot for this purpose. Also change above mentioned users to use this helper. [imran.f.khan@oracle.com: fix build error] Link: https://lkml.kernel.org/r/20210915175321.3472770-4-imran.f.khan@oracle.com [imran.f.khan@oracle.com: export stack_depot_snprint() to modules] Link: https://lkml.kernel.org/r/20210916133535.3592491-4-imran.f.khan@oracle.com Link: https://lkml.kernel.org/r/20210915014806.3206938-4-imran.f.khan@oracle.comSigned-off-by:
Imran Khan <imran.f.khan@oracle.com> Suggested-by:
Vlastimil Babka <vbabka@suse.cz> Acked-by:
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Imran Khan authored
To print a stack entries, users of stackdepot, first use stack_depot_fetch to get a list of stack entries and then use stack_trace_print to print this list. Provide a helper in stackdepot to print stack entries based on stackdepot handle. Also change above mentioned users to use this helper. Link: https://lkml.kernel.org/r/20210915014806.3206938-3-imran.f.khan@oracle.comSigned-off-by:
Alexander Potapenko <glider@google.com> Cc: Andrey Konovalov <andreyknvl@gmail.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Daniel Vetter <daniel@ffwll.ch> Cc: David Airlie <airlied@linux.ie> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com> Cc: Maxime Ripard <mripard@kernel.org> Cc: Thomas Zimmermann <tzimmermann@suse.de> Signed-off-by:
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Imran Khan authored
Patch series "lib, stackdepot: check stackdepot handle before accessing slabs", v2. PATCH-1: Checks validity of a stackdepot handle before proceeding to access stackdepot slab/objects. PATCH-2: Adds a helper in stackdepot, to allow users to print stack entries just by specifying the stackdepot handle. It also changes such users to use this new interface. PATCH-3: Adds a helper in stackdepot, to allow users to print stack entries into buffers just by specifying the stackdepot handle and destination buffer. It also changes such users to use this new interface. This patch (of 3): stack_depot_save allocates slabs that will be used for storing objects in future.If this slab allocation fails we may get to a situation where space allocation for a new stack_record fails, causing stack_depot_save to return 0 as handle. If user of this handle ends up invoking stack_depot_fetch with this handle value, current implementation of stack_depot_fetch will end up using slab from wrong index. To avoid this check handle value at the beginning. Link: https://lkml.kernel.org/r/20210915175321.3472770-1-imran.f.khan@oracle.com Link: https://lkml.kernel.org/r/20210915014806.3206938-1-imran.f.khan@oracle.com Link: https://lkml.kernel.org/r/20210915014806.3206938-2-imran.f.khan@oracle.comSigned-off-by:
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Lukas Bulwahn authored
Commit f9e784dc ("dt-bindings: hwlock: add sun6i_hwspinlock") adds Documentation/devicetree/bindings/hwlock/allwinner,sun6i-a31-hwspinlock.yaml, but the related commit 3c881e05 ("hwspinlock: add sun6i hardware spinlock support") adds a file reference to allwinner,sun6i-hwspinlock.yaml instead. Hence, ./scripts/get_maintainer.pl --self-test=patterns complains: warning: no file matches F: Documentation/devicetree/bindings/hwlock/allwinner,sun6i-hwspinlock.yaml Rectify this file reference in ALLWINNER HARDWARE SPINLOCK SUPPORT. Link: https://lkml.kernel.org/r/20211026141902.4865-5-lukas.bulwahn@gmail.comReviewed-by:
Wilken Gottwalt <wilken.gottwalt@posteo.net> Signed-off-by:
Lukas Bulwahn <lukas.bulwahn@gmail.com> Cc: Anitha Chrisanthus <anitha.chrisanthus@intel.com> Cc: Edmund Dea <edmund.j.dea@intel.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Joe Perches <joe@perches.com> Cc: John Stultz <john.stultz@linaro.org> Cc: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Cc: Nobuhiro Iwamatsu <nobuhiro1.iwamatsu@toshiba.co.jp> Cc: Punit Agrawal <punit1.agrawal@toshiba.co.jp> Cc: Ralf Ramsauer <ralf.ramsauer@oth-regensburg.de> Cc: Rob Herring <robh+dt@kernel.org> Cc: Sam Ravnborg <sam@ravnborg.org> Cc: Yu Chen <chenyu56@huawei.com> Signed-off-by:
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Lukas Bulwahn authored
Commit ed794057 ("drm/kmb: Build files for KeemBay Display driver") refers to the non-existing file intel,kmb_display.yaml in Documentation/devicetree/bindings/display/. Commit 5a76b1ed ("dt-bindings: display: Add support for Intel KeemBay Display") originating from the same patch series however adds the file intel,keembay-display.yaml in that directory instead. So, refer to intel,keembay-display.yaml in the INTEL KEEM BAY DRM DRIVER section instead. Link: https://lkml.kernel.org/r/20211026141902.4865-4-lukas.bulwahn@gmail.com Fixes: ed794057 ("drm/kmb: Build files for KeemBay Display driver") Signed-off-by:
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Lukas Bulwahn authored
Commit 7a6ff4c4 ("misc: hisi_hikey_usb: Driver to support onboard USB gpio hub on Hikey960") refers to the non-existing file Documentation/devicetree/bindings/misc/hisilicon-hikey-usb.yaml, but this commit's patch series does not add any related devicetree binding in misc. So, just drop this file reference in HIKEY960 ONBOARD USB GPIO HUB DRIVER. Link: https://lkml.kernel.org/r/20211026141902.4865-3-lukas.bulwahn@gmail.com Fixes: 7a6ff4c4 ("misc: hisi_hikey_usb: Driver to support onboard USB gpio hub on Hikey960") Signed-off-by:
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Lukas Bulwahn authored
Patch series "Rectify file references for dt-bindings in MAINTAINERS", v5. A patch series that cleans up some file references for dt-bindings in MAINTAINERS. This patch (of 4): Commit 836863a0 ("MAINTAINERS: Add information for Toshiba Visconti ARM SoCs") refers to the non-existing file toshiba,tmpv7700-pinctrl.yaml in ./Documentation/devicetree/bindings/pinctrl/. Commit 1825c1fe ("pinctrl: Add DT bindings for Toshiba Visconti TMPV7700 SoC") originating from the same patch series however adds the file toshiba,visconti-pinctrl.yaml in that directory instead. So, refer to toshiba,visconti-pinctrl.yaml in the ARM/TOSHIBA VISCONTI ARCHITECTURE section instead. Link: https://lkml.kernel.org/r/20211026141902.4865-1-lukas.bulwahn@gmail.com Link: https://lkml.kernel.org/r/20211026141902.4865-2-lukas.bulwahn@gmail.com Fixes: 836863a0 ("MAINTAINERS: Add information for Toshiba Visconti ARM SoCs") Signed-off-by:
Nobuhiro Iwamatsu <nobuhiro1.iwamatsu@toshiba.co.jp> Reviewed-by:
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Kees Cook authored
I'd like more continuity of review for the exec and binfmt (and ELF) stuff. Eric and I have been the most active lately, so list us as reviewers. Link: https://lkml.kernel.org/r/20211006180200.1178142-1-keescook@chromium.orgSigned-off-by:
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Colin Ian King authored
Colin King has moved to Intel to update gmail and Canonical email addresses. Link: https://lkml.kernel.org/r/20211102231617.78569-1-colin.i.king@gmail.comSigned-off-by:
Colin Ian King <colin.i.king@gmail.com> Signed-off-by:
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Rasmus Villemoes authored
_Static_assert() is evaluated already in the compiler's frontend, and gives a somehat more to-the-point error, compared to the BUILD_BUG_ON macro, which only fires after the optimizer has had a chance to eliminate calls to functions marked with __attribute__((error)). In theory, this might make builds a tiny bit faster. There's also a little less gunk in the error message emitted: lib/sort.c: In function `foo': include/linux/build_bug.h:78:41: error: static assertion failed: "pointer type mismatch in container_of()" 78 | #define __static_assert(expr, msg, ...) _Static_assert(expr, msg) compared to lib/sort.c: In function `foo': include/linux/compiler_types.h:322:38: error: call to `__compiletime_assert_2' declared with attribute error: pointer type mismatch in container_of() 322 | _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__) While at it, fix the copy-pasto in container_of_safe(). Link: https://lkml.kernel.org/r/20211015090530.2774079-1-linux@rasmusvillemoes.dk Link: https://lore.kernel.org/lkml/20211014132331.GA4811@kernel.org/T/Signed-off-by:Rasmus Villemoes <linux@rasmusvillemoes.dk> Reviewed-by:
Miguel Ojeda <ojeda@kernel.org> Acked-by:
Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by:
Nick Desaulniers <ndesaulniers@google.com> Signed-off-by:
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Stephen Rothwell authored
bottom_half.h needs _THIS_IP_ to be standalone, so split that and _RET_IP_ out from kernel.h into the new instruction_pointer.h. kernel.h directly needs them, so include it there and replace the include of kernel.h with this new file in bottom_half.h. Link: https://lkml.kernel.org/r/20211028161248.45232-1-andriy.shevchenko@linux.intel.comSigned-off-by:
Stephen Rothwell <sfr@canb.auug.org.au> Signed-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. [akpm@linux-foundation.org: include math.h for round_up()] Link: https://lkml.kernel.org/r/20211027150548.80042-1-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/20211027150528.80003-1-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/20211027150437.79921-1-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. [akpm@linux-foundation.org: cxd2880_common.h needs bits.h for GENMASK()] [andriy.shevchenko@linux.intel.com: delay.h: fix for removed kernel.h] Link: https://lkml.kernel.org/r/20211028170143.56523-1-andriy.shevchenko@linux.intel.com [akpm@linux-foundation.org: include/linux/fwnode.h needs bits.h for BIT()] Link: https://lkml.kernel.org/r/20211027150324.79827-1-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/20211013170417.87909-8-andriy.shevchenko@linux.intel.comSigned-off-by:
Sakari Ailus <sakari.ailus@linux.intel.com> Cc: Boqun Feng <boqun.feng@gmail.com> Cc: Brendan Higgins <brendanhiggins@google.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jonathan Cameron <jic23@kernel.org> Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Cc: Mauro Carvalho Chehab <mchehab@kernel.org> Cc: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Thorsten Leemhuis <regressions@leemhuis.info> Cc: Waiman Long <longman@redhat.com> Cc: Will Deacon <will@kernel.org> Signed-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/20211013170417.87909-7-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/20211013170417.87909-6-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/20211013170417.87909-5-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/20211013170417.87909-4-andriy.shevchenko@linux.intel.comSigned-off-by:
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Andy Shevchenko authored
kernel.h is being used as a dump for all kinds of stuff for a long time. Here is the attempt cleaning it up by splitting out container_of() and typeof_member() macros. For time being include new header back to kernel.h to avoid twisted indirected includes for existing users. Note, there are _a lot_ of headers and modules that include kernel.h solely for one of these macros and this allows to unburden compiler for the twisted inclusion paths and to make new code cleaner in the future. Link: https://lkml.kernel.org/r/20211013170417.87909-3-andriy.shevchenko@linux.intel.comSigned-off-by:
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Andy Shevchenko authored
Patch series "kernel.h further split", v5. kernel.h is a set of something which is not related to each other and often used in non-crossed compilation units, especially when drivers need only one or two macro definitions from it. This patch (of 7): There is no evidence we need kernel.h inclusion in certain headers. Drop unneeded <linux/kernel.h> inclusion from other headers. [sfr@canb.auug.org.au: bottom_half.h needs kernel] Link: https://lkml.kernel.org/r/20211015202908.1c417ae2@canb.auug.org.au Link: https://lkml.kernel.org/r/20211013170417.87909-1-andriy.shevchenko@linux.intel.com Link: https://lkml.kernel.org/r/20211013170417.87909-2-andriy.shevchenko@linux.intel.comSigned-off-by:
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Stephen Brennan authored
Problem Description: When running running ~128 parallel instances of TZ=/etc/localtime ps -fe >/dev/null on a 128CPU machine, the %sys utilization reaches 97%, and perf shows the following code path as being responsible for heavy contention on the d_lockref spinlock: walk_component() lookup_fast() d_revalidate() pid_revalidate() // returns -ECHILD unlazy_child() lockref_get_not_dead(&nd->path.dentry->d_lockref) <-- contention The reason is that pid_revalidate() is triggering a drop from RCU to ref path walk mode. All concurrent path lookups thus try to grab a reference to the dentry for /proc/, before re-executing pid_revalidate() and then stepping into the /proc/$pid directory. Thus there is huge spinlock contention. This patch allows pid_revalidate() to execute in RCU mode, meaning that the path lookup can successfully enter the /proc/$pid directory while still in RCU mode. Later on, the path lookup may still drop into ref mode, but the contention will be much reduced at this point. By applying this patch, %sys utilization falls to around 85% under the same workload, and the number of ps processes executed per unit time increases by 3x-4x. Although this particular workload is a bit contrived, we have seen some large collections of eager monitoring scripts which produced similarly high %sys time due to contention in the /proc directory. As a result this patch, Al noted that several procfs methods which were only called in ref-walk mode could now be called from RCU mode. To ensure that this patch is safe, I audited all the inode get_link and permission() implementations, as well as dentry d_revalidate() implementations, in fs/proc. The purpose here is to ensure that they either are safe to call in RCU (i.e. don't sleep) or correctly bail out of RCU mode if they don't support it. My analysis shows that all at-risk procfs methods are safe to call under RCU, and thus this patch is safe. Procfs RCU-walk Analysis: This analysis is up-to-date with 5.15-rc3. When called under RCU mode, these functions have arguments as follows: * get_link() receives a NULL dentry pointer when called in RCU mode. * permission() receives MAY_NOT_BLOCK in the mode parameter when called from RCU. * d_revalidate() receives LOOKUP_RCU in flags. For the following functions, either they are trivially RCU safe, or they explicitly bail at the beginning of the function when they run: proc_ns_get_link (bails out) proc_get_link (RCU safe) proc_pid_get_link (bails out) map_files_d_revalidate (bails out) map_misc_d_revalidate (bails out) proc_net_d_revalidate (RCU safe) proc_sys_revalidate (bails out, also not under /proc/$pid) tid_fd_revalidate (bails out) proc_sys_permission (not under /proc/$pid) The remainder of the functions require a bit more detail: * proc_fd_permission: RCU safe. All of the body of this function is under rcu_read_lock(), except generic_permission() which declares itself RCU safe in its documentation string. * proc_self_get_link uses GFP_ATOMIC in the RCU case, so it is RCU aware and otherwise looks safe. The same is true of proc_thread_self_get_link. * proc_map_files_get_link: calls ns_capable, which calls capable(), and thus calls into the audit code (see note #1 below). The remainder is just a call to the trivially safe proc_pid_get_link(). * proc_pid_permission: calls ptrace_may_access(), which appears RCU safe, although it does call into the "security_ptrace_access_check()" hook, which looks safe under smack and selinux. Just the audit code is of concern. Also uses get_task_struct() and put_task_struct(), see note #2 below. * proc_tid_comm_permission: Appears safe, though calls put_task_struct (see note #2 below). Note #1: Most of the concern of RCU safety has centered around the audit code. However, since b17ec22f ("selinux: slow_avc_audit has become non-blocking"), it's safe to call this code under RCU. So all of the above are safe by my estimation. Note #2: get_task_struct() and put_task_struct(): The majority of get_task_struct() is under RCU read lock, and in any case it is a simple increment. But put_task_struct() is complex, given that it could at some point free the task struct, and this process has many steps which I couldn't manually verify. However, several other places call put_task_struct() under RCU, so it appears safe to use here too (see kernel/hung_task.c:165 or rcu/tree-stall.h:296) Patch description: pid_revalidate() drops from RCU into REF lookup mode. When many threads are resolving paths within /proc in parallel, this can result in heavy spinlock contention on d_lockref as each thread tries to grab a reference to the /proc dentry (and drop it shortly thereafter). Investigation indicates that it is not necessary to drop RCU in pid_revalidate(), as no RCU data is modified and the function never sleeps. So, remove the LOOKUP_RCU check. Link: https://lkml.kernel.org/r/20211004175629.292270-2-stephen.s.brennan@oracle.comSigned-off-by:Stephen Brennan <stephen.s.brennan@oracle.com> Cc: Konrad Wilk <konrad.wilk@oracle.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Matthew Wilcox <willy@infradead.org> Cc: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by:
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David Hildenbrand authored
Although virtio-mem currently supports reading unplugged memory in the hypervisor, this will change in the future, indicated to the device via a new feature flag. We similarly sanitized /proc/kcore access recently. [1] Let's register a vmcore callback, to allow vmcore code to check if a PFN belonging to a virtio-mem device is either currently plugged and should be dumped or is currently unplugged and should not be accessed, instead mapping the shared zeropage or returning zeroes when reading. This is important when not capturing /proc/vmcore via tools like "makedumpfile" that can identify logically unplugged virtio-mem memory via PG_offline in the memmap, but simply by e.g., copying the file. Distributions that support virtio-mem+kdump have to make sure that the virtio_mem module will be part of the kdump kernel or the kdump initrd; dracut was recently [2] extended to include virtio-mem in the generated initrd. As long as no special kdump kernels are used, this will automatically make sure that virtio-mem will be around in the kdump initrd and sanitize /proc/vmcore access -- with dracut. With this series, we'll send one virtio-mem state request for every ~2 MiB chunk of virtio-mem memory indicated in the vmcore that we intend to read/map. In the future, we might want to allow building virtio-mem for kdump mode only, even without CONFIG_MEMORY_HOTPLUG and friends: this way, we could support special stripped-down kdump kernels that have many other config options disabled; we'll tackle that once required. Further, we might want to try sensing bigger blocks (e.g., memory sections) first before falling back to device blocks on demand. Tested with Fedora rawhide, which contains a recent kexec-tools version (considering "System RAM (virtio_mem)" when creating the vmcore header) and a recent dracut version (including the virtio_mem module in the kdump initrd). Link: https://lkml.kernel.org/r/20210526093041.8800-1-david@redhat.com [1] Link: https://github.com/dracutdevs/dracut/pull/1157 [2] Link: https://lkml.kernel.org/r/20211005121430.30136-10-david@redhat.comSigned-off-by:
David Hildenbrand <david@redhat.com> Cc: Baoquan He <bhe@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Dave Young <dyoung@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jason Wang <jasowang@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Oscar Salvador <osalvador@suse.de> Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com> Cc: Stefano Stabellini <sstabellini@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vivek Goyal <vgoyal@redhat.com> Signed-off-by:
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David Hildenbrand authored
Let's prepare for a new virtio-mem kdump mode in which we don't actually hot(un)plug any memory but only observe the state of device blocks. Link: https://lkml.kernel.org/r/20211005121430.30136-9-david@redhat.comSigned-off-by:
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David Hildenbrand authored
Let's prepare for a new virtio-mem kdump mode in which we don't actually hot(un)plug any memory but only observe the state of device blocks. Link: https://lkml.kernel.org/r/20211005121430.30136-8-david@redhat.comSigned-off-by:
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David Hildenbrand authored
Let's prepare for a new virtio-mem kdump mode in which we don't actually hot(un)plug any memory but only observe the state of device blocks. Link: https://lkml.kernel.org/r/20211005121430.30136-7-david@redhat.comSigned-off-by:
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David Hildenbrand authored
Let's support multiple registered callbacks, making sure that registering vmcore callbacks cannot fail. Make the callback return a bool instead of an int, handling how to deal with errors internally. Drop unused HAVE_OLDMEM_PFN_IS_RAM. We soon want to make use of this infrastructure from other drivers: virtio-mem, registering one callback for each virtio-mem device, to prevent reading unplugged virtio-mem memory. Handle it via a generic vmcore_cb structure, prepared for future extensions: for example, once we support virtio-mem on s390x where the vmcore is completely constructed in the second kernel, we want to detect and add plugged virtio-mem memory ranges to the vmcore in order for them to get dumped properly. Handle corner cases that are unexpected and shouldn't happen in sane setups: registering a callback after the vmcore has already been opened (warn only) and unregistering a callback after the vmcore has already been opened (warn and essentially read only zeroes from that point on). Link: https://lkml.kernel.org/r/20211005121430.30136-6-david@redhat.comSigned-off-by:
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