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* media: ov7740: get rid of extra ifdefsmfe/media/v4l2-subdev-stubsMarco Felsch2019-04-031-14/+13
| | | | | | | | | | | | | We can drop the ifdef dance since the v4l2_subdev_get_try_format return the correct value in both cases with or without CONFIG_VIDEO_V4L2_SUBDEV_API is enabled. The patch is based on Lubomir's series [1]. [1] https://patchwork.kernel.org/cover/10703017/ Cc: Lubomir Rintel <lkundrak@v3.sk> Signed-off-by: Marco Felsch <m.felsch@pengutronix.de>
* media: ov7670: get rid of extra ifdefsMarco Felsch2019-04-031-12/+7
| | | | | | | | | | | | | We can drop the ifdef dance since the v4l2_subdev_get_try_format return the correct value in both cases with or without CONFIG_VIDEO_V4L2_SUBDEV_API is enabled. The patch is based on Lubomir's series [1]. [1] https://patchwork.kernel.org/cover/10703017/ Cc: Lubomir Rintel <lkundrak@v3.sk> Signed-off-by: Marco Felsch <m.felsch@pengutronix.de>
* media: ov5695: get rid of extra ifdefsMarco Felsch2019-04-031-12/+14
| | | | | | | | | | | | | We can drop the ifdef dance since the v4l2_subdev_get_try_format return the correct value in both cases with or without CONFIG_VIDEO_V4L2_SUBDEV_API is enabled. The patch is based on Lubomir's series [1]. [1] https://patchwork.kernel.org/cover/10703017/ Cc: Lubomir Rintel <lkundrak@v3.sk> Signed-off-by: Marco Felsch <m.felsch@pengutronix.de>
* media: ov2680: get rid of extra ifdefsMarco Felsch2019-04-031-11/+9
| | | | | | | | | | | | | We can drop the ifdef dance since the v4l2_subdev_get_try_format return the correct value in both cases with or without CONFIG_VIDEO_V4L2_SUBDEV_API is enabled. The patch is based on Lubomir's series [1]. [1] https://patchwork.kernel.org/cover/10703017/ Cc: Lubomir Rintel <lkundrak@v3.sk> Signed-off-by: Marco Felsch <m.felsch@pengutronix.de>
* media: ov2659: get rid of extra ifdefsMarco Felsch2019-04-031-8/+7
| | | | | | | | | | | | | We can drop the ifdef dance since the v4l2_subdev_get_try_format return the correct value in both cases with or without CONFIG_VIDEO_V4L2_SUBDEV_API is enabled. The patch is based on Lubomir's series [1]. [1] https://patchwork.kernel.org/cover/10703017/ Cc: Lubomir Rintel <lkundrak@v3.sk> Signed-off-by: Marco Felsch <m.felsch@pengutronix.de>
* media: v4l2-subdev: add stubs for v4l2_subdev_get_try_*Marco Felsch2019-04-031-1/+28
| | | | | | | | | | | | | | | | | | | | | | | In case of missing CONFIG_VIDEO_V4L2_SUBDEV_API those helpers aren't available. So each driver have to add ifdefs around those helpers or add the CONFIG_VIDEO_V4L2_SUBDEV_API as dependcy. Make these helpers available in case of CONFIG_VIDEO_V4L2_SUBDEV_API isn't set to avoid ifdefs. This approach is less error prone too. Signed-off-by: Marco Felsch <m.felsch@pengutronix.de> --- The patch was previously part of series [1]. Since I want to get series [1] merged in 5.2 I split this possible stopper out of the serie and prepared a own series for it. I applied Jacopos comments and switched to Lubomir's approach [2]. During discussion on series [2] Sakari pointed out Hans approach [3] which didn't got into the kernel due to Mauro's concerns. So I think this would be the smalles common dennominator. [1] https://patchwork.kernel.org/cover/10786553/ [2] https://patchwork.kernel.org/patch/10703029/ [3] https://patchwork.linuxtv.org/patch/53370/
* Linux 5.1-rc1Linus Torvalds2019-03-171-2/+2
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* Merge tag 'kbuild-v5.1-2' of ↵Linus Torvalds2019-03-1757-156/+153
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild Pull more Kbuild updates from Masahiro Yamada: - add more Build-Depends to Debian source package - prefix header search paths with $(srctree)/ - make modpost show verbose section mismatch warnings - avoid hard-coded CROSS_COMPILE for h8300 - fix regression for Debian make-kpkg command - add semantic patch to detect missing put_device() - fix some warnings of 'make deb-pkg' - optimize NOSTDINC_FLAGS evaluation - add warnings about redundant generic-y - clean up Makefiles and scripts * tag 'kbuild-v5.1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: kconfig: remove stale lxdialog/.gitignore kbuild: force all architectures except um to include mandatory-y kbuild: warn redundant generic-y Revert "modsign: Abort modules_install when signing fails" kbuild: Make NOSTDINC_FLAGS a simply expanded variable kbuild: deb-pkg: avoid implicit effects coccinelle: semantic code search for missing put_device() kbuild: pkg: grep include/config/auto.conf instead of $KCONFIG_CONFIG kbuild: deb-pkg: introduce is_enabled and if_enabled_echo to builddeb kbuild: deb-pkg: add CONFIG_ prefix to kernel config options kbuild: add workaround for Debian make-kpkg kbuild: source include/config/auto.conf instead of ${KCONFIG_CONFIG} unicore32: simplify linker script generation for decompressor h8300: use cc-cross-prefix instead of hardcoding h8300-unknown-linux- kbuild: move archive command to scripts/Makefile.lib modpost: always show verbose warning for section mismatch ia64: prefix header search path with $(srctree)/ libfdt: prefix header search paths with $(srctree)/ deb-pkg: generate correct build dependencies
| * kconfig: remove stale lxdialog/.gitignoreMasahiro Yamada2019-03-171-4/+0
| | | | | | | | | | | | | | | | | | When this .gitignore was added, lxdialog was an independent hostprogs-y. Now that all objects in lxdialog/ are directly linked to mconf, the lxdialog is no longer generated. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
| * kbuild: force all architectures except um to include mandatory-yMasahiro Yamada2019-03-1729-47/+18
| | | | | | | | | | | | | | | | | | | | | | | | Currently, every arch/*/include/uapi/asm/Kbuild explicitly includes the common Kbuild.asm file. Factor out the duplicated include directives to scripts/Makefile.asm-generic so that no architecture would opt out of the mandatory-y mechanism. um is not forced to include mandatory-y since it is a very exceptional case which does not support UAPI. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
| * kbuild: warn redundant generic-yMasahiro Yamada2019-03-1712-13/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The generic-y is redundant under the following condition: - arch has its own implementation - the same header is added to generated-y - the same header is added to mandatory-y If a redundant generic-y is found, the warning like follows is displayed: scripts/Makefile.asm-generic:20: redundant generic-y found in arch/arm/include/asm/Kbuild: timex.h I fixed up arch Kbuild files found by this. Suggested-by: Sam Ravnborg <sam@ravnborg.org> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
| * Revert "modsign: Abort modules_install when signing fails"Douglas Anderson2019-03-171-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This reverts commit caf6fe91ddf62a96401e21e9b7a07227440f4185. The commit was fine but is no longer needed as of commit 3a2429e1faf4 ("kbuild: change if_changed_rule for multi-line recipe"). Let's go back to using ";" to be consistent. For some discussion, see: https://lkml.kernel.org/r/CAK7LNASde0Q9S5GKeQiWhArfER4S4wL1=R_FW8q0++_X3T5=hQ@mail.gmail.com Signed-off-by: Douglas Anderson <dianders@chromium.org> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
| * kbuild: Make NOSTDINC_FLAGS a simply expanded variableDouglas Anderson2019-03-171-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | During a simple no-op (nothing changed) build I saw 39 invocations of the C compiler with the argument "-print-file-name=include". We don't need to call the C compiler 39 times for this--one time will suffice. Let's change NOSTDINC_FLAGS to a simply expanded variable to avoid this since there doesn't appear to be any reason it should be recursively expanded. On my build this shaved ~400 ms off my "no-op" build. Note that the recursive expansion seems to date back to the (really old) commit e8f5bdb02ce0 ("[PATCH] Makefile include path ordering"). It's a little unclear to me if the point of that patch was to switch the variable to be recursively expanded (which it did) or to avoid directly assigning to NOSTDINC_FLAGS (AKA to switch to +=) because someone else (out of tree?) was setting it. I presume later since if the only goal was to switch to recursive expansion the patch would have just removed the ":". Signed-off-by: Douglas Anderson <dianders@chromium.org> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
| * kbuild: deb-pkg: avoid implicit effectsArseny Maslennikov2019-03-171-1/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * The man page for dpkg-source(1) notes: > -b, --build directory [format-specific-parameters] > Build a source package (--build since dpkg 1.17.14). > <...> > > dpkg-source will build the source package with the first > format found in this ordered list: the format indicated > with the --format command line option, the format > indicated in debian/source/format, “1.0”. The fallback > to “1.0” is deprecated and will be removed at some point > in the future, you should always document the desired > source format in debian/source/format. See section > SOURCE PACKAGE FORMATS for an extensive description of > the various source package formats. Thus it would be more foolproof to explicitly use 1.0 (as we always did) than to rely on dpkg-source's defaults. * In a similar vein, debian/rules is not made executable by mkdebian, and dpkg-source warns about that but still silently fixes the file. Let's be explicit once again. Signed-off-by: Arseny Maslennikov <ar@cs.msu.ru> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
| * coccinelle: semantic code search for missing put_device()Wen Yang2019-03-171-0/+56
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The of_find_device_by_node() takes a reference to the underlying device structure, we should release that reference. The implementation of this semantic code search is: In a function, for a local variable returned by calling of_find_device_by_node(), a, if it is released by a function such as put_device()/of_dev_put()/platform_device_put() after the last use, it is considered that there is no reference leak; b, if it is passed back to the caller via dev_get_drvdata()/platform_get_drvdata()/get_device(), etc., the reference will be released in other functions, and the current function also considers that there is no reference leak; c, for the rest of the situation, the current function should release the reference by calling put_device, this code search will report the corresponding error message. By using this semantic code search, we have found some object reference leaks, such as: commit 11907e9d3533 ("ASoC: fsl-asoc-card: fix object reference leaks in fsl_asoc_card_probe") commit a12085d13997 ("mtd: rawnand: atmel: fix possible object reference leak") commit 11493f26856a ("mtd: rawnand: jz4780: fix possible object reference leak") There are still dozens of reference leaks in the current kernel code. Further, for the case of b, the object returned to other functions may also have a reference leak, we will continue to develop other cocci scripts to further check the reference leak. Signed-off-by: Wen Yang <wen.yang99@zte.com.cn> Reviewed-by: Julia Lawall <Julia.Lawall@lip6.fr> Reviewed-by: Markus Elfring <Markus.Elfring@web.de> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
| * kbuild: pkg: grep include/config/auto.conf instead of $KCONFIG_CONFIGMasahiro Yamada2019-03-143-3/+3
| | | | | | | | | | | | | | | | | | | | | | This will be a little more efficient since unset CONFIG options are stripped away from auto.conf, and we can hard-code the path to auto.conf since it is never overridden. include/config/kernel.release is generated before %pkg is run. So, it is guaranteed auto.conf is up-to-date. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
| * kbuild: deb-pkg: introduce is_enabled and if_enabled_echo to builddebMasahiro Yamada2019-03-141-13/+19
| | | | | | | | | | | | | | | | | | | | I think is_enabled() and if_enable_echo() in scripts/package/mkdebian are useful. builddeb also has many repetitive greps over the kernel config, so I borrowed the idea to clean it up. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
| * kbuild: deb-pkg: add CONFIG_ prefix to kernel config optionsMasahiro Yamada2019-03-141-17/+17
| | | | | | | | | | | | | | | | | | | | | | | | This might be a kind of bike-shed, but I personally prefer grep'able code. I often do 'git grep CONFIG_FOO' instead of 'git grep FOO' when I want to know where that CONFIG option is used. This makes code longer, but I hope this is acceptable level. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
| * kbuild: add workaround for Debian make-kpkgMasahiro Yamada2019-03-141-0/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Since commit 3812b8c5c5d5 ("kbuild: make -r/-R effective in top Makefile for old Make versions"), make-kpkg is not working. make-kpkg directly includes the top Makefile of Linux kernel, and appends some debian_* targets. /usr/share/kernel-package/ruleset/kernel_version.mk: # Include the kernel makefile override dot-config := 1 include Makefile dot-config := 1 I did not know the kernel Makefile was used in that way, and it is hard to guarantee the behavior when the kernel Makefile is included by another Makefile from a different project. It looks like Debian Stretch stopped providing make-kpkg. Maybe it is obsolete and being replaced with 'make deb-pkg' etc. but still widely used. This commit adds a workaround; if the top Makefile is included by another Makefile, skip sub-make in order to make the main part visible. 'MAKEFLAGS += -rR' does not become effective for GNU Make < 4.0, but Debian/Ubuntu is already using newer versions. The effect of this commit: Debian 8 (Jessie) : Fixed Debian 9 (Stretch) : make-kpkg (kernel-package) is not provided Ubuntu 14.04 LTS : NOT Fixed Ubuntu 16.04 LTS : Fixed Ubuntu 18.04 LTS : Fixed This commit cannot fix Ubuntu 14.04 because it installs GNU Make 3.81, but its support will end in Apr 2019, which is before the Linux v5.1 release. I added warning so that nobody would try to include the top Makefile. Fixes: 3812b8c5c5d5 ("kbuild: make -r/-R effective in top Makefile for old Make versions") Reported-by: Liz Zhang <lizzha@microsoft.com> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Tested-by: Lili Deng <v-lide@microsoft.com> Cc: Manoj Srivastava <srivasta@debian.org>
| * kbuild: source include/config/auto.conf instead of ${KCONFIG_CONFIG}Masahiro Yamada2019-03-142-16/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | As commit 423a8155facf ("kbuild: Fix reading of .config in link-vmlinux.sh") addressed, some shells fail to perform '.' if ${KCONFIG_CONFIG} does not contain a slash at all. Instead, we can source include/config/auto.conf, which obviously contain slashes, and we do not expect its file path overridden by a user. Perhaps, the performance might be slightly better since unset CONFIG options are stripped from include/config/auto.conf. scripts/setlocalversion already works this way. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
| * unicore32: simplify linker script generation for decompressorMasahiro Yamada2019-03-142-4/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | When I was searching for unneeded $(KCONFIG_CONFIG) usages, I noticed this strange build dependency. It can use $(call if_changed,...) in case ZTEXTADDR and ZBSSADDR are changed, but even a simpler way is to use the pattern rule in scripts/Makefile.build. This is what arch/arm/boot/compressed/Makefile does. I did only build test. I confirmed equivalent vmlinux.lds was generated. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
| * h8300: use cc-cross-prefix instead of hardcoding h8300-unknown-linux-Masahiro Yamada2019-03-141-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It believe it is a bad idea to hardcode a specific compiler prefix that may or may not be installed on a user's system. It is annoying when testing features that should not require compilers at all. For example, mrproper, headers_install, etc. should work without any compiler. They look like follows on my machine. $ make ARCH=h8300 mrproper ./scripts/gcc-version.sh: line 26: h8300-unknown-linux-gcc: command not found ./scripts/gcc-version.sh: line 27: h8300-unknown-linux-gcc: command not found make: h8300-unknown-linux-gcc: Command not found make: h8300-unknown-linux-gcc: Command not found [ a bunch of the same error messages continue ] $ make ARCH=h8300 headers_install ./scripts/gcc-version.sh: line 26: h8300-unknown-linux-gcc: command not found ./scripts/gcc-version.sh: line 27: h8300-unknown-linux-gcc: command not found make: h8300-unknown-linux-gcc: Command not found HOSTCC scripts/basic/fixdep make: h8300-unknown-linux-gcc: Command not found WRAP arch/h8300/include/generated/uapi/asm/kvm_para.h [ snip ] The solution is to delete this line, or to use cc-cross-prefix like some architectures do. I chose the latter as a moderate fixup. I added an alternative 'h8300-linux-' because it is available at: https://mirrors.edge.kernel.org/pub/tools/crosstool/files/bin/x86_64/8.1.0/ Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
| * kbuild: move archive command to scripts/Makefile.libMasahiro Yamada2019-03-143-8/+7
| | | | | | | | | | | | | | | | | | scripts/Makefile.build and arch/s390/boot/Makefile use the same command (thin archiving with symbol table creation). Avoid the code duplication, and move it to scripts/Makefile.lib. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
| * modpost: always show verbose warning for section mismatchMasahiro Yamada2019-03-142-23/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | Unless CONFIG_DEBUG_SECTION_MISMATCH is enabled, modpost only shows the number of section mismatches. If you want to know the symbols causing the issue, you need to rebuild with CONFIG_DEBUG_SECTION_MISMATCH. It is tedious. I think it is fine to show annoying warning when a new section mismatch comes in. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
| * ia64: prefix header search path with $(srctree)/Masahiro Yamada2019-03-144-6/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, the Kbuild core manipulates header search paths in a crazy way [1]. To fix this mess, I want all Makefiles to add explicit $(srctree)/ to the search paths in the srctree. Some Makefiles are already written in that way, but not all. The goal of this work is to make the notation consistent, and finally get rid of the gross hacks. Having whitespaces after -I does not matter since commit 48f6e3cf5bc6 ("kbuild: do not drop -I without parameter"). I removed some header search paths because I was able to build ia64 without them. [1]: https://patchwork.kernel.org/patch/9632347/ Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
| * libfdt: prefix header search paths with $(srctree)/Masahiro Yamada2019-03-141-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, the Kbuild core manipulates header search paths in a crazy way [1]. To fix this mess, I want all Makefiles to add explicit $(srctree)/ to the search paths in the srctree. Some Makefiles are already written in that way, but not all. The goal of this work is to make the notation consistent, and finally get rid of the gross hacks. Having whitespaces after -I does not matter since commit 48f6e3cf5bc6 ("kbuild: do not drop -I without parameter"). [1]: https://patchwork.kernel.org/patch/9632347/ Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
| * deb-pkg: generate correct build dependenciesRiku Voipio2019-03-141-1/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | bison/flex is now needed always for building for kconfig. Some build dependencies depend on kernel configuration, enable them as needed: - libelf-dev when UNWINDER_ORC is set - libssl-dev for SYSTEM_TRUSTED_KEYRING Since the libssl-dev is needed for extract_cert binary, denote with :native to install the libssl-dev for the build machines architecture, rather than for the architecture of the kernel being built. Tested-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org> Signed-off-by: Riku Voipio <riku.voipio@linaro.org> Reviewed-by: Ben Hutchings <ben@decadent.org.uk> Acked-by: maximilian attems <maks@stro.at> [masahiro.yamada: change 'flex' to 'flex | flex:native' ] Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
* | Merge branch 'x86-asm-for-linus' of ↵Linus Torvalds2019-03-173-125/+0
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 asm updates from Thomas Gleixner: "Two cleanup patches removing dead conditionals and unused code" * 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/asm: Remove unused __constant_c_x_memset() macro and inlines x86/asm: Remove dead __GNUC__ conditionals
| * | x86/asm: Remove unused __constant_c_x_memset() macro and inlinesRasmus Villemoes2019-01-121-84/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Nothing refers to the __constant_c_x_memset() macro anymore. Remove it and the two referenced static inline functions. Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: x86-ml <x86@kernel.org> Link: https://lkml.kernel.org/r/20190111084931.24601-2-linux@rasmusvillemoes.dk
| * | x86/asm: Remove dead __GNUC__ conditionalsRasmus Villemoes2019-01-123-41/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The minimum supported gcc version is >= 4.6, so these can be removed. Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: x86-ml <x86@kernel.org> Link: https://lkml.kernel.org/r/20190111084931.24601-1-linux@rasmusvillemoes.dk
* | | Merge branch 'perf-urgent-for-linus' of ↵Linus Torvalds2019-03-172-4/+4
|\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf fixes from Thomas Gleixner: "Three fixes for the fallout from the TSX errata workaround: - Prevent memory corruption caused by a unchecked out of bound array index. - Two trivial fixes to address compiler warnings" * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf/x86/intel: Make dev_attr_allow_tsx_force_abort static perf/x86: Fixup typo in stub functions perf/x86/intel: Fix memory corruption
| * | | perf/x86/intel: Make dev_attr_allow_tsx_force_abort statickbuild test robot2019-03-171-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Fixes: 400816f60c54 ("perf/x86/intel: Implement support for TSX Force Abort") Signed-off-by: kbuild test robot <lkp@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: "Peter Zijlstra (Intel)" <peterz@infradead.org> Cc: kbuild-all@01.org Cc: Borislav Petkov <bp@alien8.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Kan Liang <kan.liang@linux.intel.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20190313184243.GA10820@lkp-sb-ep06
| * | | perf/x86: Fixup typo in stub functionsPeter Zijlstra2019-03-151-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Guenter reported a build warning for CONFIG_CPU_SUP_INTEL=n: > With allmodconfig-CONFIG_CPU_SUP_INTEL, this patch results in: > > In file included from arch/x86/events/amd/core.c:8:0: > arch/x86/events/amd/../perf_event.h:1036:45: warning: ‘struct cpu_hw_event’ declared inside parameter list will not be visible outside of this definition or declaration > static inline int intel_cpuc_prepare(struct cpu_hw_event *cpuc, int cpu) While harmless (an unsed pointer is an unused pointer, no matter the type) it needs fixing. Reported-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: stable@vger.kernel.org Fixes: d01b1f96a82e ("perf/x86/intel: Make cpuc allocations consistent") Link: http://lkml.kernel.org/r/20190315081410.GR5996@hirez.programming.kicks-ass.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | perf/x86/intel: Fix memory corruptionPeter Zijlstra2019-03-151-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Through: validate_event() x86_pmu.get_event_constraints(.idx=-1) tfa_get_event_constraints() dyn_constraint() cpuc->constraint_list[-1] is used, which is an obvious out-of-bound access. In this case, simply skip the TFA constraint code, there is no event constraint with just PMC3, therefore the code will never result in the empty set. Fixes: 400816f60c54 ("perf/x86/intel: Implement support for TSX Force Abort") Reported-by: Tony Jones <tonyj@suse.com> Reported-by: "DSouza, Nelson" <nelson.dsouza@intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Tony Jones <tonyj@suse.com> Tested-by: "DSouza, Nelson" <nelson.dsouza@intel.com> Cc: eranian@google.com Cc: jolsa@redhat.com Cc: stable@kernel.org Link: https://lkml.kernel.org/r/20190314130705.441549378@infradead.org
* | | | Merge tag 'for-linus-5.1b-rc1b-tag' of ↵Linus Torvalds2019-03-171-1/+4
|\ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip Pull xen fix from Juergen Gross: "A fix for a Xen bug introduced by David's series for excluding ballooned pages in vmcores" * tag 'for-linus-5.1b-rc1b-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: xen/balloon: Fix mapping PG_offline pages to user space
| * | | | xen/balloon: Fix mapping PG_offline pages to user spaceDavid Hildenbrand2019-03-151-1/+4
| |/ / / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The XEN balloon driver - in contrast to other balloon drivers - allows to map some inflated pages to user space. Such pages are allocated via alloc_xenballooned_pages() and freed via free_xenballooned_pages(). The pfn space of these allocated pages is used to map other things by the hypervisor using hypercalls. Pages marked with PG_offline must never be mapped to user space (as this page type uses the mapcount field of struct pages). So what we can do is, clear/set PG_offline when allocating/freeing an inflated pages. This way, most inflated pages can be excluded by dumping tools and the "reused for other purpose" balloon pages are correctly not marked as PG_offline. Fixes: 77c4adf6a6df (xen/balloon: mark inflated pages PG_offline) Reported-by: Julien Grall <julien.grall@arm.com> Tested-by: Julien Grall <julien.grall@arm.com> Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Juergen Gross <jgross@suse.com> Signed-off-by: Juergen Gross <jgross@suse.com>
* | | | Merge tag '9p-for-5.1' of git://github.com/martinetd/linuxLinus Torvalds2019-03-177-32/+55
|\ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull 9p updates from Dominique Martinet: "Here is a 9p update for 5.1; there honestly hasn't been much. Two fixes (leak on invalid mount argument and possible deadlock on i_size update on 32bit smp) and a fall-through warning cleanup" * tag '9p-for-5.1' of git://github.com/martinetd/linux: 9p/net: fix memory leak in p9_client_create 9p: use inode->i_lock to protect i_size_write() under 32-bit 9p: mark expected switch fall-through
| * | | | 9p/net: fix memory leak in p9_client_createzhengbin2019-03-131-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If msize is less than 4096, we should close and put trans, destroy tagpool, not just free client. This patch fixes that. Link: http://lkml.kernel.org/m/1552464097-142659-1-git-send-email-zhengbin13@huawei.com Cc: stable@vger.kernel.org Fixes: 574d356b7a02 ("9p/net: put a lower bound on msize") Reported-by: Hulk Robot <hulkci@huawei.com> Signed-off-by: zhengbin <zhengbin13@huawei.com> Signed-off-by: Dominique Martinet <dominique.martinet@cea.fr>
| * | | | 9p: use inode->i_lock to protect i_size_write() under 32-bitHou Tao2019-03-035-30/+53
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Use inode->i_lock to protect i_size_write(), else i_size_read() in generic_fillattr() may loop infinitely in read_seqcount_begin() when multiple processes invoke v9fs_vfs_getattr() or v9fs_vfs_getattr_dotl() simultaneously under 32-bit SMP environment, and a soft lockup will be triggered as show below: watchdog: BUG: soft lockup - CPU#5 stuck for 22s! [stat:2217] Modules linked in: CPU: 5 PID: 2217 Comm: stat Not tainted 5.0.0-rc1-00005-g7f702faf5a9e #4 Hardware name: Generic DT based system PC is at generic_fillattr+0x104/0x108 LR is at 0xec497f00 pc : [<802b8898>] lr : [<ec497f00>] psr: 200c0013 sp : ec497e20 ip : ed608030 fp : ec497e3c r10: 00000000 r9 : ec497f00 r8 : ed608030 r7 : ec497ebc r6 : ec497f00 r5 : ee5c1550 r4 : ee005780 r3 : 0000052d r2 : 00000000 r1 : ec497f00 r0 : ed608030 Flags: nzCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment none Control: 10c5387d Table: ac48006a DAC: 00000051 CPU: 5 PID: 2217 Comm: stat Not tainted 5.0.0-rc1-00005-g7f702faf5a9e #4 Hardware name: Generic DT based system Backtrace: [<8010d974>] (dump_backtrace) from [<8010dc88>] (show_stack+0x20/0x24) [<8010dc68>] (show_stack) from [<80a1d194>] (dump_stack+0xb0/0xdc) [<80a1d0e4>] (dump_stack) from [<80109f34>] (show_regs+0x1c/0x20) [<80109f18>] (show_regs) from [<801d0a80>] (watchdog_timer_fn+0x280/0x2f8) [<801d0800>] (watchdog_timer_fn) from [<80198658>] (__hrtimer_run_queues+0x18c/0x380) [<801984cc>] (__hrtimer_run_queues) from [<80198e60>] (hrtimer_run_queues+0xb8/0xf0) [<80198da8>] (hrtimer_run_queues) from [<801973e8>] (run_local_timers+0x28/0x64) [<801973c0>] (run_local_timers) from [<80197460>] (update_process_times+0x3c/0x6c) [<80197424>] (update_process_times) from [<801ab2b8>] (tick_nohz_handler+0xe0/0x1bc) [<801ab1d8>] (tick_nohz_handler) from [<80843050>] (arch_timer_handler_virt+0x38/0x48) [<80843018>] (arch_timer_handler_virt) from [<80180a64>] (handle_percpu_devid_irq+0x8c/0x240) [<801809d8>] (handle_percpu_devid_irq) from [<8017ac20>] (generic_handle_irq+0x34/0x44) [<8017abec>] (generic_handle_irq) from [<8017b344>] (__handle_domain_irq+0x6c/0xc4) [<8017b2d8>] (__handle_domain_irq) from [<801022e0>] (gic_handle_irq+0x4c/0x88) [<80102294>] (gic_handle_irq) from [<80101a30>] (__irq_svc+0x70/0x98) [<802b8794>] (generic_fillattr) from [<8056b284>] (v9fs_vfs_getattr_dotl+0x74/0xa4) [<8056b210>] (v9fs_vfs_getattr_dotl) from [<802b8904>] (vfs_getattr_nosec+0x68/0x7c) [<802b889c>] (vfs_getattr_nosec) from [<802b895c>] (vfs_getattr+0x44/0x48) [<802b8918>] (vfs_getattr) from [<802b8a74>] (vfs_statx+0x9c/0xec) [<802b89d8>] (vfs_statx) from [<802b9428>] (sys_lstat64+0x48/0x78) [<802b93e0>] (sys_lstat64) from [<80101000>] (ret_fast_syscall+0x0/0x28) [dominique.martinet@cea.fr: updated comment to not refer to a function in another subsystem] Link: http://lkml.kernel.org/r/20190124063514.8571-2-houtao1@huawei.com Cc: stable@vger.kernel.org Fixes: 7549ae3e81cc ("9p: Use the i_size_[read, write]() macros instead of using inode->i_size directly.") Reported-by: Xing Gaopeng <xingaopeng@huawei.com> Signed-off-by: Hou Tao <houtao1@huawei.com> Signed-off-by: Dominique Martinet <dominique.martinet@cea.fr>
| * | | | 9p: mark expected switch fall-throughGustavo A. R. Silva2019-01-231-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In preparation to enabling -Wimplicit-fallthrough, mark switch cases where we are expecting to fall through. This patch fixes the following warning: net/9p/trans_xen.c:514:6: warning: this statement may fall through [-Wimplicit-fallthrough=] Warning level 3 was used: -Wimplicit-fallthrough=3 This patch is part of the ongoing efforts to enabling -Wimplicit-fallthrough Link: http://lkml.kernel.org/r/20190123071632.GA8039@embeddedor Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> Signed-off-by: Dominique Martinet <dominique.martinet@cea.fr>
* | | | | Merge tag 'pidfd-v5.1-rc1' of ↵Linus Torvalds2019-03-1611-6/+538
|\ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux Pull pidfd system call from Christian Brauner: "This introduces the ability to use file descriptors from /proc/<pid>/ as stable handles on struct pid. Even if a pid is recycled the handle will not change. For a start these fds can be used to send signals to the processes they refer to. With the ability to use /proc/<pid> fds as stable handles on struct pid we can fix a long-standing issue where after a process has exited its pid can be reused by another process. If a caller sends a signal to a reused pid it will end up signaling the wrong process. With this patchset we enable a variety of use cases. One obvious example is that we can now safely delegate an important part of process management - sending signals - to processes other than the parent of a given process by sending file descriptors around via scm rights and not fearing that the given process will have been recycled in the meantime. It also allows for easy testing whether a given process is still alive or not by sending signal 0 to a pidfd which is quite handy. There has been some interest in this feature e.g. from systems management (systemd, glibc) and container managers. I have requested and gotten comments from glibc to make sure that this syscall is suitable for their needs as well. In the future I expect it to take on most other pid-based signal syscalls. But such features are left for the future once they are needed. This has been sitting in linux-next for quite a while and has not caused any issues. It comes with selftests which verify basic functionality and also test that a recycled pid cannot be signaled via a pidfd. Jon has written about a prior version of this patchset. It should cover the basic functionality since not a lot has changed since then: https://lwn.net/Articles/773459/ The commit message for the syscall itself is extensively documenting the syscall, including it's functionality and extensibility" * tag 'pidfd-v5.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux: selftests: add tests for pidfd_send_signal() signal: add pidfd_send_signal() syscall
| * | | | | selftests: add tests for pidfd_send_signal()Christian Brauner2019-03-053-0/+388
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | As suggested by Andrew Morton in [1] add selftests for the new sys_pidfd_send_signal() syscall: /* test_pidfd_send_signal_syscall_support */ Test whether the pidfd_send_signal() syscall is supported and the tests can be run or need to be skipped. /* test_pidfd_send_signal_simple_success */ Test whether sending a signal via a pidfd works. /* test_pidfd_send_signal_exited_fail */ Verify that sending a signal to an already exited process fails with ESRCH. /* test_pidfd_send_signal_recycled_pid_fail */ Verify that a recycled pid cannot be signaled via a pidfd referring to an already exited process that had the same pid (cf. [2], [3]). [1]: https://lore.kernel.org/lkml/20181228152012.dbf0508c2508138efc5f2bbe@linux-foundation.org/ [2]: https://lore.kernel.org/lkml/20181230210245.GA30252@mail.hallyn.com/ [3]: https://lore.kernel.org/lkml/20181230232711.7aayb7vnhogbv4co@brauner.io/ Cc: Arnd Bergmann <arnd@arndb.de> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Kees Cook <keescook@chromium.org> Cc: Jann Horn <jannh@google.com> Cc: Andy Lutomirsky <luto@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Aleksa Sarai <cyphar@cyphar.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Florian Weimer <fweimer@redhat.com> Signed-off-by: Christian Brauner <christian@brauner.io> Reviewed-by: Tycho Andersen <tycho@tycho.ws> Acked-by: Serge Hallyn <serge@hallyn.com>
| * | | | | signal: add pidfd_send_signal() syscallChristian Brauner2019-03-058-7/+151
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The kill() syscall operates on process identifiers (pid). After a process has exited its pid can be reused by another process. If a caller sends a signal to a reused pid it will end up signaling the wrong process. This issue has often surfaced and there has been a push to address this problem [1]. This patch uses file descriptors (fd) from proc/<pid> as stable handles on struct pid. Even if a pid is recycled the handle will not change. The fd can be used to send signals to the process it refers to. Thus, the new syscall pidfd_send_signal() is introduced to solve this problem. Instead of pids it operates on process fds (pidfd). /* prototype and argument /* long pidfd_send_signal(int pidfd, int sig, siginfo_t *info, unsigned int flags); /* syscall number 424 */ The syscall number was chosen to be 424 to align with Arnd's rework in his y2038 to minimize merge conflicts (cf. [25]). In addition to the pidfd and signal argument it takes an additional siginfo_t and flags argument. If the siginfo_t argument is NULL then pidfd_send_signal() is equivalent to kill(<positive-pid>, <signal>). If it is not NULL pidfd_send_signal() is equivalent to rt_sigqueueinfo(). The flags argument is added to allow for future extensions of this syscall. It currently needs to be passed as 0. Failing to do so will cause EINVAL. /* pidfd_send_signal() replaces multiple pid-based syscalls */ The pidfd_send_signal() syscall currently takes on the job of rt_sigqueueinfo(2) and parts of the functionality of kill(2), Namely, when a positive pid is passed to kill(2). It will however be possible to also replace tgkill(2) and rt_tgsigqueueinfo(2) if this syscall is extended. /* sending signals to threads (tid) and process groups (pgid) */ Specifically, the pidfd_send_signal() syscall does currently not operate on process groups or threads. This is left for future extensions. In order to extend the syscall to allow sending signal to threads and process groups appropriately named flags (e.g. PIDFD_TYPE_PGID, and PIDFD_TYPE_TID) should be added. This implies that the flags argument will determine what is signaled and not the file descriptor itself. Put in other words, grouping in this api is a property of the flags argument not a property of the file descriptor (cf. [13]). Clarification for this has been requested by Eric (cf. [19]). When appropriate extensions through the flags argument are added then pidfd_send_signal() can additionally replace the part of kill(2) which operates on process groups as well as the tgkill(2) and rt_tgsigqueueinfo(2) syscalls. How such an extension could be implemented has been very roughly sketched in [14], [15], and [16]. However, this should not be taken as a commitment to a particular implementation. There might be better ways to do it. Right now this is intentionally left out to keep this patchset as simple as possible (cf. [4]). /* naming */ The syscall had various names throughout iterations of this patchset: - procfd_signal() - procfd_send_signal() - taskfd_send_signal() In the last round of reviews it was pointed out that given that if the flags argument decides the scope of the signal instead of different types of fds it might make sense to either settle for "procfd_" or "pidfd_" as prefix. The community was willing to accept either (cf. [17] and [18]). Given that one developer expressed strong preference for the "pidfd_" prefix (cf. [13]) and with other developers less opinionated about the name we should settle for "pidfd_" to avoid further bikeshedding. The "_send_signal" suffix was chosen to reflect the fact that the syscall takes on the job of multiple syscalls. It is therefore intentional that the name is not reminiscent of neither kill(2) nor rt_sigqueueinfo(2). Not the fomer because it might imply that pidfd_send_signal() is a replacement for kill(2), and not the latter because it is a hassle to remember the correct spelling - especially for non-native speakers - and because it is not descriptive enough of what the syscall actually does. The name "pidfd_send_signal" makes it very clear that its job is to send signals. /* zombies */ Zombies can be signaled just as any other process. No special error will be reported since a zombie state is an unreliable state (cf. [3]). However, this can be added as an extension through the @flags argument if the need ever arises. /* cross-namespace signals */ The patch currently enforces that the signaler and signalee either are in the same pid namespace or that the signaler's pid namespace is an ancestor of the signalee's pid namespace. This is done for the sake of simplicity and because it is unclear to what values certain members of struct siginfo_t would need to be set to (cf. [5], [6]). /* compat syscalls */ It became clear that we would like to avoid adding compat syscalls (cf. [7]). The compat syscall handling is now done in kernel/signal.c itself by adding __copy_siginfo_from_user_generic() which lets us avoid compat syscalls (cf. [8]). It should be noted that the addition of __copy_siginfo_from_user_any() is caused by a bug in the original implementation of rt_sigqueueinfo(2) (cf. 12). With upcoming rework for syscall handling things might improve significantly (cf. [11]) and __copy_siginfo_from_user_any() will not gain any additional callers. /* testing */ This patch was tested on x64 and x86. /* userspace usage */ An asciinema recording for the basic functionality can be found under [9]. With this patch a process can be killed via: #define _GNU_SOURCE #include <errno.h> #include <fcntl.h> #include <signal.h> #include <stdio.h> #include <stdlib.h> #include <string.h> #include <sys/stat.h> #include <sys/syscall.h> #include <sys/types.h> #include <unistd.h> static inline int do_pidfd_send_signal(int pidfd, int sig, siginfo_t *info, unsigned int flags) { #ifdef __NR_pidfd_send_signal return syscall(__NR_pidfd_send_signal, pidfd, sig, info, flags); #else return -ENOSYS; #endif } int main(int argc, char *argv[]) { int fd, ret, saved_errno, sig; if (argc < 3) exit(EXIT_FAILURE); fd = open(argv[1], O_DIRECTORY | O_CLOEXEC); if (fd < 0) { printf("%s - Failed to open \"%s\"\n", strerror(errno), argv[1]); exit(EXIT_FAILURE); } sig = atoi(argv[2]); printf("Sending signal %d to process %s\n", sig, argv[1]); ret = do_pidfd_send_signal(fd, sig, NULL, 0); saved_errno = errno; close(fd); errno = saved_errno; if (ret < 0) { printf("%s - Failed to send signal %d to process %s\n", strerror(errno), sig, argv[1]); exit(EXIT_FAILURE); } exit(EXIT_SUCCESS); } /* Q&A * Given that it seems the same questions get asked again by people who are * late to the party it makes sense to add a Q&A section to the commit * message so it's hopefully easier to avoid duplicate threads. * * For the sake of progress please consider these arguments settled unless * there is a new point that desperately needs to be addressed. Please make * sure to check the links to the threads in this commit message whether * this has not already been covered. */ Q-01: (Florian Weimer [20], Andrew Morton [21]) What happens when the target process has exited? A-01: Sending the signal will fail with ESRCH (cf. [22]). Q-02: (Andrew Morton [21]) Is the task_struct pinned by the fd? A-02: No. A reference to struct pid is kept. struct pid - as far as I understand - was created exactly for the reason to not require to pin struct task_struct (cf. [22]). Q-03: (Andrew Morton [21]) Does the entire procfs directory remain visible? Just one entry within it? A-03: The same thing that happens right now when you hold a file descriptor to /proc/<pid> open (cf. [22]). Q-04: (Andrew Morton [21]) Does the pid remain reserved? A-04: No. This patchset guarantees a stable handle not that pids are not recycled (cf. [22]). Q-05: (Andrew Morton [21]) Do attempts to signal that fd return errors? A-05: See {Q,A}-01. Q-06: (Andrew Morton [22]) Is there a cleaner way of obtaining the fd? Another syscall perhaps. A-06: Userspace can already trivially retrieve file descriptors from procfs so this is something that we will need to support anyway. Hence, there's no immediate need to add another syscalls just to make pidfd_send_signal() not dependent on the presence of procfs. However, adding a syscalls to get such file descriptors is planned for a future patchset (cf. [22]). Q-07: (Andrew Morton [21] and others) This fd-for-a-process sounds like a handy thing and people may well think up other uses for it in the future, probably unrelated to signals. Are the code and the interface designed to permit such future applications? A-07: Yes (cf. [22]). Q-08: (Andrew Morton [21] and others) Now I think about it, why a new syscall? This thing is looking rather like an ioctl? A-08: This has been extensively discussed. It was agreed that a syscall is preferred for a variety or reasons. Here are just a few taken from prior threads. Syscalls are safer than ioctl()s especially when signaling to fds. Processes are a core kernel concept so a syscall seems more appropriate. The layout of the syscall with its four arguments would require the addition of a custom struct for the ioctl() thereby causing at least the same amount or even more complexity for userspace than a simple syscall. The new syscall will replace multiple other pid-based syscalls (see description above). The file-descriptors-for-processes concept introduced with this syscall will be extended with other syscalls in the future. See also [22], [23] and various other threads already linked in here. Q-09: (Florian Weimer [24]) What happens if you use the new interface with an O_PATH descriptor? A-09: pidfds opened as O_PATH fds cannot be used to send signals to a process (cf. [2]). Signaling processes through pidfds is the equivalent of writing to a file. Thus, this is not an operation that operates "purely at the file descriptor level" as required by the open(2) manpage. See also [4]. /* References */ [1]: https://lore.kernel.org/lkml/20181029221037.87724-1-dancol@google.com/ [2]: https://lore.kernel.org/lkml/874lbtjvtd.fsf@oldenburg2.str.redhat.com/ [3]: https://lore.kernel.org/lkml/20181204132604.aspfupwjgjx6fhva@brauner.io/ [4]: https://lore.kernel.org/lkml/20181203180224.fkvw4kajtbvru2ku@brauner.io/ [5]: https://lore.kernel.org/lkml/20181121213946.GA10795@mail.hallyn.com/ [6]: https://lore.kernel.org/lkml/20181120103111.etlqp7zop34v6nv4@brauner.io/ [7]: https://lore.kernel.org/lkml/36323361-90BD-41AF-AB5B-EE0D7BA02C21@amacapital.net/ [8]: https://lore.kernel.org/lkml/87tvjxp8pc.fsf@xmission.com/ [9]: https://asciinema.org/a/IQjuCHew6bnq1cr78yuMv16cy [11]: https://lore.kernel.org/lkml/F53D6D38-3521-4C20-9034-5AF447DF62FF@amacapital.net/ [12]: https://lore.kernel.org/lkml/87zhtjn8ck.fsf@xmission.com/ [13]: https://lore.kernel.org/lkml/871s6u9z6u.fsf@xmission.com/ [14]: https://lore.kernel.org/lkml/20181206231742.xxi4ghn24z4h2qki@brauner.io/ [15]: https://lore.kernel.org/lkml/20181207003124.GA11160@mail.hallyn.com/ [16]: https://lore.kernel.org/lkml/20181207015423.4miorx43l3qhppfz@brauner.io/ [17]: https://lore.kernel.org/lkml/CAGXu5jL8PciZAXvOvCeCU3wKUEB_dU-O3q0tDw4uB_ojMvDEew@mail.gmail.com/ [18]: https://lore.kernel.org/lkml/20181206222746.GB9224@mail.hallyn.com/ [19]: https://lore.kernel.org/lkml/20181208054059.19813-1-christian@brauner.io/ [20]: https://lore.kernel.org/lkml/8736rebl9s.fsf@oldenburg.str.redhat.com/ [21]: https://lore.kernel.org/lkml/20181228152012.dbf0508c2508138efc5f2bbe@linux-foundation.org/ [22]: https://lore.kernel.org/lkml/20181228233725.722tdfgijxcssg76@brauner.io/ [23]: https://lwn.net/Articles/773459/ [24]: https://lore.kernel.org/lkml/8736rebl9s.fsf@oldenburg.str.redhat.com/ [25]: https://lore.kernel.org/lkml/CAK8P3a0ej9NcJM8wXNPbcGUyOUZYX+VLoDFdbenW3s3114oQZw@mail.gmail.com/ Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Jann Horn <jannh@google.com> Cc: Andy Lutomirsky <luto@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Florian Weimer <fweimer@redhat.com> Signed-off-by: Christian Brauner <christian@brauner.io> Reviewed-by: Tycho Andersen <tycho@tycho.ws> Reviewed-by: Kees Cook <keescook@chromium.org> Reviewed-by: David Howells <dhowells@redhat.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Serge Hallyn <serge@hallyn.com> Acked-by: Aleksa Sarai <cyphar@cyphar.com>
* | | | | | Merge tag 'devdax-for-5.1' of ↵Linus Torvalds2019-03-1630-537/+1111
|\ \ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm Pull device-dax updates from Dan Williams: "New device-dax infrastructure to allow persistent memory and other "reserved" / performance differentiated memories, to be assigned to the core-mm as "System RAM". Some users want to use persistent memory as additional volatile memory. They are willing to cope with potential performance differences, for example between DRAM and 3D Xpoint, and want to use typical Linux memory management apis rather than a userspace memory allocator layered over an mmap() of a dax file. The administration model is to decide how much Persistent Memory (pmem) to use as System RAM, create a device-dax-mode namespace of that size, and then assign it to the core-mm. The rationale for device-dax is that it is a generic memory-mapping driver that can be layered over any "special purpose" memory, not just pmem. On subsequent boots udev rules can be used to restore the memory assignment. One implication of using pmem as RAM is that mlock() no longer keeps data off persistent media. For this reason it is recommended to enable NVDIMM Security (previously merged for 5.0) to encrypt pmem contents at rest. We considered making this recommendation an actively enforced requirement, but in the end decided to leave it as a distribution / administrator policy to allow for emulation and test environments that lack security capable NVDIMMs. Summary: - Replace the /sys/class/dax device model with /sys/bus/dax, and include a compat driver so distributions can opt-in to the new ABI. - Allow for an alternative driver for the device-dax address-range - Introduce the 'kmem' driver to hotplug / assign a device-dax address-range to the core-mm. - Arrange for the device-dax target-node to be onlined so that the newly added memory range can be uniquely referenced by numa apis" NOTE! I'm not entirely happy with the whole "PMEM as RAM" model because we currently have special - and very annoying rules in the kernel about accessing PMEM only with the "MC safe" accessors, because machine checks inside the regular repeat string copy functions can be fatal in some (not described) circumstances. And apparently the PMEM modules can cause that a lot more than regular RAM. The argument is that this happens because PMEM doesn't necessarily get scrubbed at boot like RAM does, but that is planned to be added for the user space tooling. Quoting Dan from another email: "The exposure can be reduced in the volatile-RAM case by scanning for and clearing errors before it is onlined as RAM. The userspace tooling for that can be in place before v5.1-final. There's also runtime notifications of errors via acpi_nfit_uc_error_notify() from background scrubbers on the DIMM devices. With that mechanism the kernel could proactively clear newly discovered poison in the volatile case, but that would be additional development more suitable for v5.2. I understand the concern, and the need to highlight this issue by tapping the brakes on feature development, but I don't see PMEM as RAM making the situation worse when the exposure is also there via DAX in the PMEM case. Volatile-RAM is arguably a safer use case since it's possible to repair pages where the persistent case needs active application coordination" * tag 'devdax-for-5.1' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: device-dax: "Hotplug" persistent memory for use like normal RAM mm/resource: Let walk_system_ram_range() search child resources mm/memory-hotplug: Allow memory resources to be children mm/resource: Move HMM pr_debug() deeper into resource code mm/resource: Return real error codes from walk failures device-dax: Add a 'modalias' attribute to DAX 'bus' devices device-dax: Add a 'target_node' attribute device-dax: Auto-bind device after successful new_id acpi/nfit, device-dax: Identify differentiated memory with a unique numa-node device-dax: Add /sys/class/dax backwards compatibility device-dax: Add support for a dax override driver device-dax: Move resource pinning+mapping into the common driver device-dax: Introduce bus + driver model device-dax: Start defining a dax bus model device-dax: Remove multi-resource infrastructure device-dax: Kill dax_region base device-dax: Kill dax_region ida
| * | | | | | device-dax: "Hotplug" persistent memory for use like normal RAMDave Hansen2019-02-284-0/+126
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This is intended for use with NVDIMMs that are physically persistent (physically like flash) so that they can be used as a cost-effective RAM replacement. Intel Optane DC persistent memory is one implementation of this kind of NVDIMM. Currently, a persistent memory region is "owned" by a device driver, either the "Direct DAX" or "Filesystem DAX" drivers. These drivers allow applications to explicitly use persistent memory, generally by being modified to use special, new libraries. (DIMM-based persistent memory hardware/software is described in great detail here: Documentation/nvdimm/nvdimm.txt). However, this limits persistent memory use to applications which *have* been modified. To make it more broadly usable, this driver "hotplugs" memory into the kernel, to be managed and used just like normal RAM would be. To make this work, management software must remove the device from being controlled by the "Device DAX" infrastructure: echo dax0.0 > /sys/bus/dax/drivers/device_dax/unbind and then tell the new driver that it can bind to the device: echo dax0.0 > /sys/bus/dax/drivers/kmem/new_id After this, there will be a number of new memory sections visible in sysfs that can be onlined, or that may get onlined by existing udev-initiated memory hotplug rules. This rebinding procedure is currently a one-way trip. Once memory is bound to "kmem", it's there permanently and can not be unbound and assigned back to device_dax. The kmem driver will never bind to a dax device unless the device is *explicitly* bound to the driver. There are two reasons for this: One, since it is a one-way trip, it can not be undone if bound incorrectly. Two, the kmem driver destroys data on the device. Think of if you had good data on a pmem device. It would be catastrophic if you compile-in "kmem", but leave out the "device_dax" driver. kmem would take over the device and write volatile data all over your good data. This inherits any existing NUMA information for the newly-added memory from the persistent memory device that came from the firmware. On Intel platforms, the firmware has guarantees that require each socket's persistent memory to be in a separate memory-only NUMA node. That means that this patch is not expected to create NUMA nodes, but will simply hotplug memory into existing nodes. Because NUMA nodes are created, the existing NUMA APIs and tools are sufficient to create policies for applications or memory areas to have affinity for or an aversion to using this memory. There is currently some metadata at the beginning of pmem regions. The section-size memory hotplug restrictions, plus this small reserved area can cause the "loss" of a section or two of capacity. This should be fixable in follow-on patches. But, as a first step, losing 256MB of memory (worst case) out of hundreds of gigabytes is a good tradeoff vs. the required code to fix this up precisely. This calculation is also the reason we export memory_block_size_bytes(). Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Reviewed-by: Keith Busch <keith.busch@intel.com> Cc: Dave Jiang <dave.jiang@intel.com> Cc: Ross Zwisler <zwisler@kernel.org> Cc: Vishal Verma <vishal.l.verma@intel.com> Cc: Tom Lendacky <thomas.lendacky@amd.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Michal Hocko <mhocko@suse.com> Cc: linux-nvdimm@lists.01.org Cc: linux-kernel@vger.kernel.org Cc: linux-mm@kvack.org Cc: Huang Ying <ying.huang@intel.com> Cc: Fengguang Wu <fengguang.wu@intel.com> Cc: Borislav Petkov <bp@suse.de> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Yaowei Bai <baiyaowei@cmss.chinamobile.com> Cc: Takashi Iwai <tiwai@suse.de> Cc: Jerome Glisse <jglisse@redhat.com> Reviewed-by: Vishal Verma <vishal.l.verma@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
| * | | | | | mm/resource: Let walk_system_ram_range() search child resourcesDave Hansen2019-02-281-1/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In the process of onlining memory, we use walk_system_ram_range() to find the actual RAM areas inside of the area being onlined. However, it currently only finds memory resources which are "top-level" iomem_resources. Children are not currently searched which causes it to skip System RAM in areas like this (in the format of /proc/iomem): a0000000-bfffffff : Persistent Memory (legacy) a0000000-afffffff : System RAM Changing the true->false here allows children to be searched as well. We need this because we add a new "System RAM" resource underneath the "persistent memory" resource when we use persistent memory in a volatile mode. Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Cc: Keith Busch <keith.busch@intel.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Jiang <dave.jiang@intel.com> Cc: Ross Zwisler <zwisler@kernel.org> Cc: Vishal Verma <vishal.l.verma@intel.com> Cc: Tom Lendacky <thomas.lendacky@amd.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Michal Hocko <mhocko@suse.com> Cc: linux-nvdimm@lists.01.org Cc: linux-kernel@vger.kernel.org Cc: linux-mm@kvack.org Cc: Huang Ying <ying.huang@intel.com> Cc: Fengguang Wu <fengguang.wu@intel.com> Cc: Borislav Petkov <bp@suse.de> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Yaowei Bai <baiyaowei@cmss.chinamobile.com> Cc: Takashi Iwai <tiwai@suse.de> Cc: Jerome Glisse <jglisse@redhat.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
| * | | | | | mm/memory-hotplug: Allow memory resources to be childrenDave Hansen2019-02-281-13/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The mm/resource.c code is used to manage the physical address space. The current resource configuration can be viewed in /proc/iomem. An example of this is at the bottom of this description. The nvdimm subsystem "owns" the physical address resources which map to persistent memory and has resources inserted for them as "Persistent Memory". The best way to repurpose this for volatile use is to leave the existing resource in place, but add a "System RAM" resource underneath it. This clearly communicates the ownership relationship of this memory. The request_resource_conflict() API only deals with the top-level resources. Replace it with __request_region() which will search for !IORESOURCE_BUSY areas lower in the resource tree than the top level. We *could* also simply truncate the existing top-level "Persistent Memory" resource and take over the released address space. But, this means that if we ever decide to hot-unplug the "RAM" and give it back, we need to recreate the original setup, which may mean going back to the BIOS tables. This should have no real effect on the existing collision detection because the areas that truly conflict should be marked IORESOURCE_BUSY. 00000000-00000fff : Reserved 00001000-0009fbff : System RAM 0009fc00-0009ffff : Reserved 000a0000-000bffff : PCI Bus 0000:00 000c0000-000c97ff : Video ROM 000c9800-000ca5ff : Adapter ROM 000f0000-000fffff : Reserved 000f0000-000fffff : System ROM 00100000-9fffffff : System RAM 01000000-01e071d0 : Kernel code 01e071d1-027dfdff : Kernel data 02dc6000-0305dfff : Kernel bss a0000000-afffffff : Persistent Memory (legacy) a0000000-a7ffffff : System RAM b0000000-bffdffff : System RAM bffe0000-bfffffff : Reserved c0000000-febfffff : PCI Bus 0000:00 Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Reviewed-by: Vishal Verma <vishal.l.verma@intel.com> Cc: Dave Jiang <dave.jiang@intel.com> Cc: Ross Zwisler <zwisler@kernel.org> Cc: Vishal Verma <vishal.l.verma@intel.com> Cc: Tom Lendacky <thomas.lendacky@amd.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Michal Hocko <mhocko@suse.com> Cc: linux-nvdimm@lists.01.org Cc: linux-kernel@vger.kernel.org Cc: linux-mm@kvack.org Cc: Huang Ying <ying.huang@intel.com> Cc: Fengguang Wu <fengguang.wu@intel.com> Cc: Borislav Petkov <bp@suse.de> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Yaowei Bai <baiyaowei@cmss.chinamobile.com> Cc: Takashi Iwai <tiwai@suse.de> Cc: Jerome Glisse <jglisse@redhat.com> Cc: Keith Busch <keith.busch@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
| * | | | | | mm/resource: Move HMM pr_debug() deeper into resource codeDave Hansen2019-02-282-5/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | HMM consumes physical address space for its own use, even though nothing is mapped or accessible there. It uses a special resource description (IORES_DESC_DEVICE_PRIVATE_MEMORY) to uniquely identify these areas. When HMM consumes address space, it makes a best guess about what to consume. However, it is possible that a future memory or device hotplug can collide with the reserved area. In the case of these conflicts, there is an error message in register_memory_resource(). Later patches in this series move register_memory_resource() from using request_resource_conflict() to __request_region(). Unfortunately, __request_region() does not return the conflict like the previous function did, which makes it impossible to check for IORES_DESC_DEVICE_PRIVATE_MEMORY in a conflicting resource. Instead of warning in register_memory_resource(), move the check into the core resource code itself (__request_region()) where the conflicting resource _is_ available. This has the added bonus of producing a warning in case of HMM conflicts with devices *or* RAM address space, as opposed to the RAM- only warnings that were there previously. Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Reviewed-by: Jerome Glisse <jglisse@redhat.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Jiang <dave.jiang@intel.com> Cc: Ross Zwisler <zwisler@kernel.org> Cc: Vishal Verma <vishal.l.verma@intel.com> Cc: Tom Lendacky <thomas.lendacky@amd.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Michal Hocko <mhocko@suse.com> Cc: linux-nvdimm@lists.01.org Cc: linux-kernel@vger.kernel.org Cc: linux-mm@kvack.org Cc: Huang Ying <ying.huang@intel.com> Cc: Fengguang Wu <fengguang.wu@intel.com> Cc: Keith Busch <keith.busch@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
| * | | | | | mm/resource: Return real error codes from walk failuresDave Hansen2019-02-281-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | walk_system_ram_range() can return an error code either becuase *it* failed, or because the 'func' that it calls returned an error. The memory hotplug does the following: ret = walk_system_ram_range(..., func); if (ret) return ret; and 'ret' makes it out to userspace, eventually. The problem s, walk_system_ram_range() failues that result from *it* failing (as opposed to 'func') return -1. That leads to a very odd -EPERM (-1) return code out to userspace. Make walk_system_ram_range() return -EINVAL for internal failures to keep userspace less confused. This return code is compatible with all the callers that I audited. Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Reviewed-by: Bjorn Helgaas <bhelgaas@google.com> Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc) Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Jiang <dave.jiang@intel.com> Cc: Ross Zwisler <zwisler@kernel.org> Cc: Vishal Verma <vishal.l.verma@intel.com> Cc: Tom Lendacky <thomas.lendacky@amd.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Michal Hocko <mhocko@suse.com> Cc: linux-nvdimm@lists.01.org Cc: linux-kernel@vger.kernel.org Cc: linux-mm@kvack.org Cc: Huang Ying <ying.huang@intel.com> Cc: Fengguang Wu <fengguang.wu@intel.com> Cc: Borislav Petkov <bp@suse.de> Cc: Yaowei Bai <baiyaowei@cmss.chinamobile.com> Cc: Takashi Iwai <tiwai@suse.de> Cc: Jerome Glisse <jglisse@redhat.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: linuxppc-dev@lists.ozlabs.org Cc: Keith Busch <keith.busch@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
| * | | | | | device-dax: Add a 'modalias' attribute to DAX 'bus' devicesVishal Verma2019-02-271-0/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add a 'modalias' attribute to devices under the DAX bus so that userspace is able to dynamically load modules as needed. Normally, udev can get the modalias from 'uevent', and that is correctly set up by the DAX bus. However other tooling such as 'libndctl' for interacting with drivers/nvdimm/, and 'libdaxctl' for drivers/dax/ can also use the modalias to dynamically load modules via libkmod lookups. The 'nd' bus set up by the libnvdimm subsystem exports a modalias attribute. Imitate this to export the same for the 'dax' bus. Cc: Dave Hansen <dave.hansen@linux.intel.com> Signed-off-by: Vishal Verma <vishal.l.verma@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
generated by cgit v1.2.3 (git 2.39.1) at 2024-05-23 10:37:01 +0000