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2020-06-04fat: don't allow to mount if the FAT length == 0OGAWA Hirofumi1-0/+6
If FAT length == 0, the image doesn't have any data. And it can be the cause of overlapping the root dir and FAT entries. Also Windows treats it as invalid format. Reported-by: syzbot+6f1624f937d9d6911e2d@syzkaller.appspotmail.com Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Marco Elver <elver@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Link: http://lkml.kernel.org/r/87r1wz8mrd.fsf@mail.parknet.co.jp Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-04init: allow distribution configuration of default initChris Down2-0/+20
Some init systems (eg. systemd) have init at their own paths, for example, /usr/lib/systemd/systemd. A compatibility symlink to one of the hardcoded init paths is provided by another package, usually named something like systemd-sysvcompat or similar. Currently distro maintainers who are hands-off on the bootloader are more or less required to include those compatibility links as part of their base distribution, because it's hard to migrate away from them since there's a risk some users will not get the message to set init= on the kernel command line appropriately. Moreover, for distributions where the init system is something the distribution itself is opinionated about (eg. Arch, which has systemd in the required `base` package), we could usually reasonably configure this ahead of time when building the distribution kernel. However, we currently simply don't have any way to configure the kernel to do this. Here's an example discussion where removing sysvcompat was discussed by distro maintainers[0]. This patch adds a new Kconfig tunable, CONFIG_DEFAULT_INIT, which if set is tried before the hardcoded fallback list. So the order of precedence is now thus: 1. init= on command line (on failure: panic) 2. CONFIG_DEFAULT_INIT (on failure: try #3) 3. Hardcoded fallback list (on failure: panic) This new config parameter will allow distribution maintainers to move away from these compatibility links safely, without having to worry that their users might not have the right init=. There are also two other benefits of this over having the distribution maintain a symlink: 1. One of the value propositions over simply having distributions maintain a /sbin/init symlink via a package is that it also frees distributions which have a preferred default, but not mandatory, init system from having their package manager fight with their users for control of /{s,}bin/init. Instead, the distribution simply makes their preference known in CONFIG_DEFAULT_INIT, and if the user installs another init system and uninstalls the default one they can still make use of /{s,}bin/init and friends for their own uses. This makes more cases Just Work(tm) without the user having to perform extra configuration via init=. 2. Since before this we don't know which path the distribution actually _intends_ to serve init from, we don't pr_err if it is simply missing, and usually will just silently put the user in a /bin/sh shell. Now that the distribution can make a declaration of intent, we can be more vocal when this init system fails to launch for any reason, even if it's simply because no file exists at that location, speeding up the palaver of init/mount dependency/etc debugging a bit. [0]: https://lists.archlinux.org/pipermail/arch-dev-public/2019-January/029435.html Signed-off-by: Chris Down <chris@chrisdown.name> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Masami Hiramatsu <mhiramat@kernel.org> Link: http://lkml.kernel.org/r/20200522160234.GA1487022@chrisdown.name Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-04elfnote: mark all .note sections SHF_ALLOCNick Desaulniers1-1/+1
ELFNOTE_START allows callers to specify flags for .pushsection assembler directives. All callsites but ELF_NOTE use "a" for SHF_ALLOC. For vdso's that explicitly use ELF_NOTE_START and BUILD_SALT, the same section is specified twice after preprocessing, once with "a" flag, once without. Example: .pushsection .note.Linux, "a", @note ; .pushsection .note.Linux, "", @note ; While GNU as allows this ordering, it warns for the opposite ordering, making these directives position dependent. We'd prefer not to precisely match this behavior in Clang's integrated assembler. Instead, the non __ASSEMBLY__ definition of ELF_NOTE uses __attribute__((section(".note.Linux"))) which is created with SHF_ALLOC, so let's make the __ASSEMBLY__ definition of ELF_NOTE consistent with C and just always use "a" flag. This allows Clang to assemble a working mainline (5.6) kernel via: $ make CC=clang AS=clang Signed-off-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Nathan Chancellor <natechancellor@gmail.com> Reviewed-by: Fangrui Song <maskray@google.com> Cc: Jeremy Fitzhardinge <jeremy@goop.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vincenzo Frascino <vincenzo.frascino@arm.com> Link: https://github.com/ClangBuiltLinux/linux/issues/913 Link: http://lkml.kernel.org/r/20200325231250.99205-1-ndesaulniers@google.com Debugged-by: Ilie Halip <ilie.halip@gmail.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-04fs/binfmt_elf: remove redundant elf_map ifndefAnthony Iliopoulos1-4/+0
The ifndef was added a long time ago to support archs that would define their own mapping function. The last user was the metag arch which was removed from the tree, and as such there are no users left. Let's kill it. Signed-off-by: Anthony Iliopoulos <ailiop@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20200402161543.4119-1-ailiop@suse.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-04checkpatch: use patch subject when reading from stdinGeert Uytterhoeven1-0/+1
While "git am" can apply an mbox file containing multiple patches (e.g. as created by b4[1], or a patch bundle downloaded from patchwork), checkpatch does not have proper support for that. When operating on an mbox, checkpatch will merge all detected tags, and complain falsely about duplicates: WARNING: Duplicate signature As modifying checkpatch to reset state in between each patch is a lot of work, a simple solution is splitting the mbox into individual patches, and invoking checkpatch for each of them. Fortunately checkpatch can read a patch from stdin, so the classic "formail" tool can be used to split the mbox, and pipe all individual patches to checkpatch: formail -s scripts/checkpatch.pl < my-mbox However, when reading a patch file from standard input, checkpatch calls it "Your patch", and reports its state as: Your patch has style problems, please review. or: Your patch has no obvious style problems and is ready for submission. Hence it can be difficult to identify which patches need to be reviewed and improved. Fix this by replacing "Your patch" by (the first line of) the email subject, if present. Note that "git mailsplit" can also be used to split an mbox, but it will create individual files for each patch, thus requiring cleanup afterwards. Formail does not have this disadvantage. [1] https://git.kernel.org/pub/scm/utils/b4/b4.git [joe@perches.com: reduce cpu usage] Link: http://lkml.kernel.org/r/c9d89bb24c7414142414c60371e210fdcf4617d2.camel@perches.com Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Joe Perches <joe@perches.com> Cc: Konstantin Ryabitsev <konstantin@linuxfoundation.org> Link: http://lkml.kernel.org/r/20200505132613.17452-1-geert+renesas@glider.be Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-04checkpatch: disallow --git and --file/--fixJoe Perches1-2/+4
Don't allow these options to be combined. Miscellanea: o Add missing $P: to some die("reason message") output Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/3dc7bdaa58490f5906efc11a4d6113e42a087723.camel@perches.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-04checkpatch: look for c99 comments in ctx_locate_commentJoe Perches1-1/+9
Some checks look for comments around a specific function like read_barrier_depends. Extend the check to support both c89 and c90 comment styles. c89 /* comment */ or c99 // comment For c99 comments, only look a 3 single lines, the line being scanned, the line above and the line below the line being scanned rather than the patch diff context. Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Tested-by: Paul E. McKenney <paulmck@kernel.org> Cc: Marco Elver <elver@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Konovalov <andreyknvl@google.com> Cc: Andy Whitcroft <apw@canonical.com> Cc: Will Deacon <will@kernel.org> Link: http://lkml.kernel.org/r/65cb075435d2f385a53c77571b491b2b09faaf8e.camel@perches.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-04checkpatch: additional MAINTAINER section entry ordering checksJoe Perches1-8/+37
There is a preferred order for the entries in MAINTAINERS sections. See commits 3b50142d8528 ("MAINTAINERS: sort field names for all entries") and 6680125ea5a2 ("MAINTAINERS: list the section entries in the preferred order") Add checkpatch tests to try to keep that ordering. Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Andy Shevchenko <andy.shevchenko@gmail.com> Link: http://lkml.kernel.org/r/17677130b3ca62d79817e6a22546bad39d7e81b4.camel@perches.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-04include/linux/bitops.h: avoid clang shift-count-overflow warningsArnd Bergmann1-1/+1
Clang normally does not warn about certain issues in inline functions when it only happens in an eliminated code path. However if something else goes wrong, it does tend to complain about the definition of hweight_long() on 32-bit targets: include/linux/bitops.h:75:41: error: shift count >= width of type [-Werror,-Wshift-count-overflow] return sizeof(w) == 4 ? hweight32(w) : hweight64(w); ^~~~~~~~~~~~ include/asm-generic/bitops/const_hweight.h:29:49: note: expanded from macro 'hweight64' define hweight64(w) (__builtin_constant_p(w) ? __const_hweight64(w) : __arch_hweight64(w)) ^~~~~~~~~~~~~~~~~~~~ include/asm-generic/bitops/const_hweight.h:21:76: note: expanded from macro '__const_hweight64' define __const_hweight64(w) (__const_hweight32(w) + __const_hweight32((w) >> 32)) ^ ~~ include/asm-generic/bitops/const_hweight.h:20:49: note: expanded from macro '__const_hweight32' define __const_hweight32(w) (__const_hweight16(w) + __const_hweight16((w) >> 16)) ^ include/asm-generic/bitops/const_hweight.h:19:72: note: expanded from macro '__const_hweight16' define __const_hweight16(w) (__const_hweight8(w) + __const_hweight8((w) >> 8 )) ^ include/asm-generic/bitops/const_hweight.h:12:9: note: expanded from macro '__const_hweight8' (!!((w) & (1ULL << 2))) + \ Adding an explicit cast to __u64 avoids that warning and makes it easier to read other output. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Christian Brauner <christian.brauner@ubuntu.com> Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Nick Desaulniers <ndesaulniers@google.com> Link: http://lkml.kernel.org/r/20200505135513.65265-1-arnd@arndb.de Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-04lib: make a test module with set/clear bitJesse Brandeburg4-0/+76
Test some bit clears/sets to make sure assembly doesn't change, and that the set_bit and clear_bit functions work and don't cause sparse warnings. Instruct Kbuild to build this file with extra warning level -Wextra, to catch new issues, and also doesn't hurt to build with C=1. This was used to test changes to arch/x86/include/asm/bitops.h. In particular, sparse (C=1) was very concerned when the last bit before a natural boundary, like 7, or 31, was being tested, as this causes sign extension (0xffffff7f) for instance when clearing bit 7. Recommended usage: make defconfig scripts/config -m CONFIG_TEST_BITOPS make modules_prepare make C=1 W=1 lib/test_bitops.ko objdump -S -d lib/test_bitops.ko insmod lib/test_bitops.ko rmmod lib/test_bitops.ko <check dmesg>, there should be no compiler/sparse warnings and no error messages in log. Link: http://lkml.kernel.org/r/20200310221747.2848474-2-jesse.brandeburg@intel.com Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> CcL Ingo Molnar <mingo@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Wei Yang <richard.weiyang@gmail.com> Cc: Christian Brauner <christian.brauner@ubuntu.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-04lib/flex_proportions.c: cleanup __fprop_inc_percpu_maxTan Hu1-4/+3
If the given type has fraction smaller than max_frac/FPROP_FRAC_BASE, the code could be modified to call __fprop_inc_percpu() directly and easier to understand. After this patch, fprop_reflect_period_percpu() will be called twice, and quicky return on pl->period == p->period test, so it would not result to significant downside of performance. Thanks for Jan's guidance. Signed-off-by: Tan Hu <tan.hu@zte.com.cn> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Jan Kara <jack@suse.cz> Cc: <xue.zhihong@zte.com.cn> Cc: Yi Wang <wang.yi59@zte.com.cn> Cc: <wang.liang82@zte.com.cn> Link: http://lkml.kernel.org/r/1589004753-27554-1-git-send-email-tan.hu@zte.com.cn Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-04lib/percpu-refcount.c: use a more common logging styleJoe Perches1-3/+3
Remove the trailing newline from the used-once pr_fmt and add it to the single use of pr_<level> in this code to use a more common logging style. Miscellanea: o Use %lu in the pr_debug format and remove the unnecessary cast Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Christophe JAILLET <christophe.jaillet@wanadoo.fr> Link: http://lkml.kernel.org/r/47372467902a047c03b0fd29aab56e0c38d3f848.camel@perches.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-04lib/zlib: remove outdated and incorrect pre-increment optimizationJann Horn1-56/+35
The zlib inflate code has an old micro-optimization based on the assumption that for pre-increment memory accesses, the compiler will generate code that fits better into the processor's pipeline than what would be generated for post-increment memory accesses. This optimization was already removed in upstream zlib in 2016: https://github.com/madler/zlib/commit/9aaec95e8211 This optimization causes UB according to C99, which says in section 6.5.6 "Additive operators": "If both the pointer operand and the result point to elements of the same array object, or one past the last element of the array object, the evaluation shall not produce an overflow; otherwise, the behavior is undefined". This UB is not only a theoretical concern, but can also cause trouble for future work on compiler-based sanitizers. According to the zlib commit, this optimization also is not optimal anymore with modern compilers. Replace uses of OFF, PUP and UP_UNALIGNED with their definitions in the POSTINC case, and remove the macro definitions, just like in the upstream patch. Signed-off-by: Jann Horn <jannh@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Mikhail Zaslonko <zaslonko@linux.ibm.com> Link: http://lkml.kernel.org/r/20200507123112.252723-1-jannh@google.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-04lib/test_lockup.c: make test_inode staticJason Yan1-1/+1
Fix the following sparse warning: lib/test_lockup.c:145:14: warning: symbol 'test_inode' was not declared. Should it be static? Reported-by: Hulk Robot <hulkci@huawei.com> Signed-off-by: Jason Yan <yanaijie@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20200417074021.46411-1-yanaijie@huawei.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-04lib: Add might_fault() to strncpy_from_user.KP Singh1-0/+1
When updating a piece of broken logic from using get_user to strncpy_from_user, we noticed that a warning which is expected when calling a function that might fault from an atomic context with pagefaults enabled disappeared. Not having this warning in place can lead to calling strncpy_from_user from an atomic context and eventually kernel crashes/stack corruption. Signed-off-by: KP Singh <kpsingh@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Jann Horn <jannh@google.com> Cc: Christophe Leroy <christophe.leroy@c-s.fr> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/20200414225705.255711-1-kpsingh@chromium.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-04lib/math: avoid trailing newline hidden in pr_fmt()Christophe JAILLET1-5/+5
pr_xxx() functions usually have a newline at the end of the logging message. Here, this newline is added via the 'pr_fmt' macro. In order to be more consistent with other files, use a more standard convention and put these newlines back in the messages themselves and remove it from the pr_fmt macro. While at it, use __func__ instead of hardcoding a function name in the last message. Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20200409163234.22830-1-christophe.jaillet@wanadoo.fr Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-04get_maintainer: fix unexpected behavior for path/to//file (double slashes)Joe Perches1-0/+2
get_maintainer behaves differently if there is a double sequential forward slash in a filename because the total number of slashes in a filename is used to match MAINTAINERS file patterns. For example: (with double slash) $ ./scripts/get_maintainer.pl -f drivers/gpu/drm//lima David Airlie <airlied@linux.ie> (maintainer:DRM DRIVERS) Daniel Vetter <daniel@ffwll.ch> (maintainer:DRM DRIVERS,commit_signer:3/42=7%) Qiang Yu <yuq825@gmail.com> (commit_signer:36/42=86%,authored:24/42=57%) Vasily Khoruzhick <anarsoul@gmail.com> (commit_signer:26/42=62%) Krzysztof Kozlowski <krzk@kernel.org> (commit_signer:5/42=12%,authored:5/42=12%) Emil Velikov <emil.velikov@collabora.com> (commit_signer:4/42=10%) dri-devel@lists.freedesktop.org (open list:DRM DRIVERS) linux-kernel@vger.kernel.org (open list) (without double slash) $ ./scripts/get_maintainer.pl -f drivers/gpu/drm/lima Qiang Yu <yuq825@gmail.com> (maintainer:DRM DRIVERS FOR LIMA) David Airlie <airlied@linux.ie> (maintainer:DRM DRIVERS) Daniel Vetter <daniel@ffwll.ch> (maintainer:DRM DRIVERS) dri-devel@lists.freedesktop.org (open list:DRM DRIVERS FOR LIMA) lima@lists.freedesktop.org (moderated list:DRM DRIVERS FOR LIMA) linux-kernel@vger.kernel.org (open list) So reduce consecutive double slashes to a single slash by using File::Spec->canonpath(). from: https://perldoc.perl.org/File/Spec/Unix.html canonpath() No physical check on the filesystem, but a logical cleanup of a path. On UNIX eliminates successive slashes and successive "/.". Reported-by: Emil Velikov <emil.l.velikov@gmail.com> Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/9a18b611813bb409fef15bc8927adab79eb9be43.camel@perches.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-04get_maintainer: add email addresses from .yaml filesJoe Perches1-15/+29
.yaml files can contain maintainer/author addresses and it seems unlikely or unnecessary that individual MAINTAINER file section entries for each .yaml file will be created. So add the email addresses found in .yaml files to the default get_maintainer output. The email addresses are marked with "(in file)" when using the "--roles" or "--rolestats" options. Miscellanea: o Change $file_emails to $email_file_emails to avoid visual naming conflicts with @file_emails Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Tested-by: Sam Ravnborg <sam@ravnborg.org> Acked-by: Sam Ravnborg <sam@ravnborg.org> Link: http://lkml.kernel.org/r/e85006456d9dbae55286c67ac5263668a72f5b58.1588022228.git.joe@perches.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-04user.c: make uidhash_table staticJason Yan1-1/+1
Fix the following sparse warning: kernel/user.c:85:19: warning: symbol 'uidhash_table' was not declared. Should it be static? Reported-by: Hulk Robot <hulkci@huawei.com> Signed-off-by: Jason Yan <yanaijie@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: David Howells <dhowells@redhat.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20200413082146.22737-1-yanaijie@huawei.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-04proc: rename "catch" function argumentAlexey Dobriyan1-4/+4
"catch" is reserved keyword in C++, rename it to something both gcc and g++ accept. Rename "ign" for symmetry. Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20200331210905.GA31680@avx2 Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-04zcomp: Use ARRAY_SIZE() for backends listAndy Shevchenko1-4/+3
Instead of keeping NULL terminated array switch to use ARRAY_SIZE() which helps to further clean up. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Minchan Kim <minchan@kernel.org> Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: http://lkml.kernel.org/r/20200508100758.51644-1-andriy.shevchenko@linux.intel.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-04include/linux/mm.h: return true in cpupid_pid_unset()Jason Yan1-1/+1
Fix the following coccicheck warning: include/linux/mm.h:1371:8-9: WARNING: return of 0/1 in function 'cpupid_pid_unset' with return type bool Signed-off-by: Jason Yan <yanaijie@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20200422071816.48879-1-yanaijie@huawei.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-04mm: use false for bool variableZou Wei3-3/+3
Fixes coccicheck warnings: mm/zbud.c:246:1-20: WARNING: Assignment of 0/1 to bool variable mm/mremap.c:777:2-8: WARNING: Assignment of 0/1 to bool variable mm/huge_memory.c:525:9-10: WARNING: return of 0/1 in function 'is_transparent_hugepage' with return type bool Reported-by: Hulk Robot <hulkci@huawei.com> Signed-off-by: Zou Wei <zou_wei@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/1586835930-47076-1-git-send-email-zou_wei@huawei.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-04mm/memory: fix a typo in comment "attampt"->"attempt"Ethon Paul1-1/+1
There is a comment in typo, fix it. Signed-off-by: Ethon Paul <ethp@qq.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20200411004043.14686-1-ethp@qq.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-04mm/page-writeback: fix a typo in comment "effictive"->"effective"Ethon Paul1-1/+1
There is a typo in comment, fix it. Signed-off-by: Ethon Paul <ethp@qq.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20200411003513.14613-1-ethp@qq.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-04mm/sparse: fix a typo in comment "convienence"->"convenience"Ethon Paul1-1/+1
There is a typo in comment, fix it. Signed-off-by: Ethon Paul <ethp@qq.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20200411002955.14545-1-ethp@qq.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-04mm/slub: fix a typo in comment "disambiguiation"->"disambiguation"Ethon Paul1-1/+1
There is a typo in comment, fix it. Signed-off-by: Ethon Paul <ethp@qq.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: David Rientjes <rientjes@google.com> Link: http://lkml.kernel.org/r/20200411002247.14468-1-ethp@qq.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-04mm: fix a typo in comment "strucure"->"structure"Ethon Paul1-1/+1
There is a typo in comment, fix it. Signed-off-by: Ethon Paul <ethp@qq.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Ralph Campbell <rcampbell@nvidia.com> Link: http://lkml.kernel.org/r/20200411064723.15855-1-ethp@qq.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-04mm, memcg: fix some typos in memcontrol.cEthon Paul1-2/+2
There are some typos in comment, fix them. s/responsiblity/responsibility s/oflline/offline Signed-off-by: Ethon Paul <ethp@qq.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20200411064246.15781-1-ethp@qq.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-04mm/frontswap: fix some typos in frontswap.cEthon Paul1-3/+3
There are some typos in comment, fix them. s/Fortunatly/Fortunately s/taked/taken s/necessory/necessary s/shink/shrink Signed-off-by: Ethon Paul <ethp@qq.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20200411064009.15727-1-ethp@qq.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-04mm/filemap: fix a typo in comment "unneccssary"->"unnecessary"Ethon Paul1-1/+1
There is a typo in comment, fix it. Signed-off-by: Ethon Paul <ethp@qq.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Ralph Campbell <rcampbell@nvidia.com> Link: http://lkml.kernel.org/r/20200411065141.15936-1-ethp@qq.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-04mm/list_lru: fix a typo in comment "numbesr"->"numbers"Ethon Paul1-1/+1
There is a typo in comment, fix it. Signed-off-by: Ethon Paul <ethp@qq.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Ralph Campbell <rcampbell@nvidia.com> Link: http://lkml.kernel.org/r/20200411071041.16161-1-ethp@qq.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-04mm/memblock: fix a typo in comment "implict"->"implicit"Ethon Paul1-1/+1
There is a typo in commet, fix it. Signed-off-by: Ethon Paul <ethp@qq.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Ralph Campbell <rcampbell@nvidia.com> Link: http://lkml.kernel.org/r/20200411070701.16097-1-ethp@qq.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-04mm/compaction: fix a typo in comment "pessemistic"->"pessimistic"Ethon Paul1-1/+1
There is a typo in comment, fix it. Signed-off-by: Ethon Paul <ethp@qq.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Ralph Campbell <rcampbell@nvidia.com> Link: http://lkml.kernel.org/r/20200411070307.16021-1-ethp@qq.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-04mm/vmsan: fix some typos in commentEthon Paul1-3/+3
There are some typos, fix them. s/regsitration/registration s/santity/sanity s/decremeting/decrementing Signed-off-by: Ethon Paul <ethp@qq.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Ralph Campbell <rcampbell@nvidia.com> Link: http://lkml.kernel.org/r/20200411071544.16222-1-ethp@qq.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-04mm/hugetlb: fix a typos in commentsEthon Paul1-8/+8
[akpm@linux-foundation.org: coding style fixes] Signed-off-by: Ethon Paul <ethp@qq.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Ralph Campbell <rcampbell@nvidia.com> Link: http://lkml.kernel.org/r/20200410163714.14085-1-ethp@qq.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-04mm: mmap: fix a typo in comment "compatbility"->"compatibility"Ethon Paul1-1/+1
There is a typo in comment, fix it. Signed-off-by: Ethon Paul <ethp@qq.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Ralph Campbell <rcampbell@nvidia.com> Link: http://lkml.kernel.org/r/20200410163206.14016-1-ethp@qq.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-04mm: ksm: fix a typo in comment "alreaady"->"already"Ethon Paul1-5/+5
There is a typo in comment, fix it. Signed-off-by: Ethon Paul <ethp@qq.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Ralph Campbell <rcampbell@nvidia.com> Link: http://lkml.kernel.org/r/20200410162427.13927-1-ethp@qq.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-04mm/memory_hotplug: fix a typo in comment "recoreded"->"recorded"Ethon Paul1-1/+1
There is a typo in comment, fix it. s/recoreded/recorded Signed-off-by: Ethon Paul <ethp@qq.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Ralph Campbell <rcampbell@nvidia.com> Link: http://lkml.kernel.org/r/20200410160328.13843-1-ethp@qq.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-04mm: replace zero-length array with flexible-array memberchenqiwu1-1/+1
The current codebase makes use of the zero-length array language extension to the C90 standard, but the preferred mechanism to declare variable-length types such as these ones is a flexible array member[1][2], introduced in C99: struct foo { int stuff; struct boo array[]; }; By making use of the mechanism above, we will get a compiler warning in case the flexible array does not occur last in the structure, which will help us prevent some kind of undefined behavior bugs from being inadvertently introduced[3] to the codebase from now on. Also, notice that, dynamic memory allocations won't be affected by this change: "Flexible array members have incomplete type, and so the sizeof operator may not be applied. As a quirk of the original implementation of zero-length arrays, sizeof evaluates to zero."[1] This issue was found with the help of Coccinelle. [1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html [2] https://github.com/KSPP/linux/issues/21 [3] commit 76497732932f ("cxgb3/l2t: Fix undefined behaviour") [akpm@linux-foundation.org: fix build] Signed-off-by: chenqiwu <chenqiwu@xiaomi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Wei Yang <richard.weiyang@gmail.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: David Hildenbrand <david@redhat.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Cc: Yang Shi <yang.shi@linux.alibaba.com> Cc: Qian Cai <cai@lca.pw> Cc: Baoquan He <bhe@redhat.com> Link: http://lkml.kernel.org/r/1586599916-15456-1-git-send-email-qiwuchen55@gmail.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-04mm/memory_hotplug: disable the functionality for 32bMichal Hocko1-0/+1
Memory hotlug is broken for 32b systems at least since c6f03e2903c9 ("mm, memory_hotplug: remove zone restrictions") which has considerably reworked how can be memory associated with movable/kernel zones. The same is not really trivial to achieve in 32b where only lowmem is the kernel zone. While we can tweak this immediate problem around there are likely other land mines hidden at other places. It is also quite dubious that there is a real usecase for the memory hotplug on 32b in the first place. Low memory is just too small to be hotplugable (for hot add) and generally unusable for hotremove. Adding more memory to highmem is also dubious because it would increase the low mem or vmalloc space pressure for memmaps. Restrict the functionality to 64b systems. This will help future development to focus on usecases that have real life application. We can remove this restriction in future in presence of a real life usecase of course but until then make it explicit that hotplug on 32b is broken and requires a non trivial amount of work to fix. Robin said: "32-bit Arm doesn't support memory hotplug, and as far as I'm aware there's little likelihood of it ever wanting to. FWIW it looks like SuperH is the only pure-32-bit architecture to have hotplug support at all" Signed-off-by: Michal Hocko <mhocko@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: David Hildenbrand <david@redhat.com> Acked-by: Baoquan He <bhe@redhat.com> Cc: Wei Yang <richardw.yang@linux.intel.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Robin Murphy <robin.murphy@arm.com> Cc: Vamshi K Sthambamkadi <vamshi.k.sthambamkadi@gmail.com> Link: http://lkml.kernel.org/r/20200218100532.GA4151@dhcp22.suse.cz Link: https://bugzilla.kernel.org/show_bug.cgi?id=206401 Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-04device-dax: add memory via add_memory_driver_managed()David Hildenbrand2-2/+27
Currently, when adding memory, we create entries in /sys/firmware/memmap/ as "System RAM". This will lead to kexec-tools to add that memory to the fixed-up initial memmap for a kexec kernel (loaded via kexec_load()). The memory will be considered initial System RAM by the kexec'd kernel and can no longer be reconfigured. This is not what happens during a real reboot. Let's add our memory via add_memory_driver_managed() now, so we won't create entries in /sys/firmware/memmap/ and indicate the memory as "System RAM (kmem)" in /proc/iomem. This allows everybody (especially kexec-tools) to identify that this memory is special and has to be treated differently than ordinary (hotplugged) System RAM. Before configuring the namespace: [root@localhost ~]# cat /proc/iomem ... 140000000-33fffffff : Persistent Memory 140000000-33fffffff : namespace0.0 3280000000-32ffffffff : PCI Bus 0000:00 After configuring the namespace: [root@localhost ~]# cat /proc/iomem ... 140000000-33fffffff : Persistent Memory 140000000-1481fffff : namespace0.0 148200000-33fffffff : dax0.0 3280000000-32ffffffff : PCI Bus 0000:00 After loading kmem before this change: [root@localhost ~]# cat /proc/iomem ... 140000000-33fffffff : Persistent Memory 140000000-1481fffff : namespace0.0 150000000-33fffffff : dax0.0 150000000-33fffffff : System RAM 3280000000-32ffffffff : PCI Bus 0000:00 After loading kmem after this change: [root@localhost ~]# cat /proc/iomem ... 140000000-33fffffff : Persistent Memory 140000000-1481fffff : namespace0.0 150000000-33fffffff : dax0.0 150000000-33fffffff : System RAM (kmem) 3280000000-32ffffffff : PCI Bus 0000:00 After a proper reboot: [root@localhost ~]# cat /proc/iomem ... 140000000-33fffffff : Persistent Memory 140000000-1481fffff : namespace0.0 148200000-33fffffff : dax0.0 3280000000-32ffffffff : PCI Bus 0000:00 Within the kexec kernel before this change: [root@localhost ~]# cat /proc/iomem ... 140000000-33fffffff : Persistent Memory 140000000-1481fffff : namespace0.0 150000000-33fffffff : System RAM 3280000000-32ffffffff : PCI Bus 0000:00 Within the kexec kernel after this change: [root@localhost ~]# cat /proc/iomem ... 140000000-33fffffff : Persistent Memory 140000000-1481fffff : namespace0.0 148200000-33fffffff : dax0.0 3280000000-32ffffffff : PCI Bus 0000:00 /sys/firmware/memmap/ before this change: 0000000000000000-000000000009fc00 (System RAM) 000000000009fc00-00000000000a0000 (Reserved) 00000000000f0000-0000000000100000 (Reserved) 0000000000100000-00000000bffdf000 (System RAM) 00000000bffdf000-00000000c0000000 (Reserved) 00000000feffc000-00000000ff000000 (Reserved) 00000000fffc0000-0000000100000000 (Reserved) 0000000100000000-0000000140000000 (System RAM) 0000000150000000-0000000340000000 (System RAM) /sys/firmware/memmap/ after a proper reboot: 0000000000000000-000000000009fc00 (System RAM) 000000000009fc00-00000000000a0000 (Reserved) 00000000000f0000-0000000000100000 (Reserved) 0000000000100000-00000000bffdf000 (System RAM) 00000000bffdf000-00000000c0000000 (Reserved) 00000000feffc000-00000000ff000000 (Reserved) 00000000fffc0000-0000000100000000 (Reserved) 0000000100000000-0000000140000000 (System RAM) /sys/firmware/memmap/ after this change: 0000000000000000-000000000009fc00 (System RAM) 000000000009fc00-00000000000a0000 (Reserved) 00000000000f0000-0000000000100000 (Reserved) 0000000000100000-00000000bffdf000 (System RAM) 00000000bffdf000-00000000c0000000 (Reserved) 00000000feffc000-00000000ff000000 (Reserved) 00000000fffc0000-0000000100000000 (Reserved) 0000000100000000-0000000140000000 (System RAM) kexec-tools already seem to basically ignore any System RAM that's not on top level when searching for areas to place kexec images - but also for determining crash areas to dump via kdump. Changing the resource name won't have an impact. Handle unloading of the driver after memory hotremove failed properly, by duplicating the string if necessary. Signed-off-by: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Cc: Wei Yang <richard.weiyang@gmail.com> Cc: Baoquan He <bhe@redhat.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Eric Biederman <ebiederm@xmission.com> Cc: Pavel Tatashin <pasha.tatashin@soleen.com> Cc: Dan Williams <dan.j.williams@intel.com> Link: http://lkml.kernel.org/r/20200508084217.9160-5-david@redhat.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-04kexec_file: don't place kexec images on IORESOURCE_MEM_DRIVER_MANAGEDDavid Hildenbrand1-0/+5
Memory flagged with IORESOURCE_MEM_DRIVER_MANAGED is special - it won't be part of the initial memmap of the kexec kernel and not all memory might be accessible. Don't place any kexec images onto it. Signed-off-by: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Cc: Wei Yang <richard.weiyang@gmail.com> Cc: Baoquan He <bhe@redhat.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Eric Biederman <ebiederm@xmission.com> Cc: Pavel Tatashin <pasha.tatashin@soleen.com> Cc: Dan Williams <dan.j.williams@intel.com> Link: http://lkml.kernel.org/r/20200508084217.9160-4-david@redhat.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-04mm/memory_hotplug: introduce add_memory_driver_managed()David Hildenbrand3-4/+61
Patch series "mm/memory_hotplug: Interface to add driver-managed system ram", v4. kexec (via kexec_load()) can currently not properly handle memory added via dax/kmem, and will have similar issues with virtio-mem. kexec-tools will currently add all memory to the fixed-up initial firmware memmap. In case of dax/kmem, this means that - in contrast to a proper reboot - how that persistent memory will be used can no longer be configured by the kexec'd kernel. In case of virtio-mem it will be harmful, because that memory might contain inaccessible pieces that require coordination with hypervisor first. In both cases, we want to let the driver in the kexec'd kernel handle detecting and adding the memory, like during an ordinary reboot. Introduce add_memory_driver_managed(). More on the samentics are in patch #1. In the future, we might want to make this behavior configurable for dax/kmem- either by configuring it in the kernel (which would then also allow to configure kexec_file_load()) or in kexec-tools by also adding "System RAM (kmem)" memory from /proc/iomem to the fixed-up initial firmware memmap. More on the motivation can be found in [1] and [2]. [1] https://lkml.kernel.org/r/20200429160803.109056-1-david@redhat.com [2] https://lkml.kernel.org/r/20200430102908.10107-1-david@redhat.com This patch (of 3): Some device drivers rely on memory they managed to not get added to the initial (firmware) memmap as system RAM - so it's not used as initial system RAM by the kernel and the driver is under control. While this is the case during cold boot and after a reboot, kexec is not aware of that and might add such memory to the initial (firmware) memmap of the kexec kernel. We need ways to teach kernel and userspace that this system ram is different. For example, dax/kmem allows to decide at runtime if persistent memory is to be used as system ram. Another future user is virtio-mem, which has to coordinate with its hypervisor to deal with inaccessible parts within memory resources. We want to let users in the kernel (esp. kexec) but also user space (esp. kexec-tools) know that this memory has different semantics and needs to be handled differently: 1. Don't create entries in /sys/firmware/memmap/ 2. Name the memory resource "System RAM ($DRIVER)" (exposed via /proc/iomem) ($DRIVER might be "kmem", "virtio_mem"). 3. Flag the memory resource IORESOURCE_MEM_DRIVER_MANAGED /sys/firmware/memmap/ [1] represents the "raw firmware-provided memory map" because "on most architectures that firmware-provided memory map is modified afterwards by the kernel itself". The primary user is kexec on x86-64. Since commit d96ae5309165 ("memory-hotplug: create /sys/firmware/memmap entry for new memory"), we add all hotplugged memory to that firmware memmap - which makes perfect sense for traditional memory hotplug on x86-64, where real HW will also add hotplugged DIMMs to the firmware memmap. We replicate what the "raw firmware-provided memory map" looks like after hot(un)plug. To keep things simple, let the user provide the full resource name instead of only the driver name - this way, we don't have to manually allocate/craft strings for memory resources. Also use the resource name to make decisions, to avoid passing additional flags. In case the name isn't "System RAM", it's special. We don't have to worry about firmware_map_remove() on the removal path. If there is no entry, it will simply return with -EINVAL. We'll adapt dax/kmem in a follow-up patch. [1] https://www.kernel.org/doc/Documentation/ABI/testing/sysfs-firmware-memmap Signed-off-by: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Cc: Wei Yang <richard.weiyang@gmail.com> Cc: Baoquan He <bhe@redhat.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Eric Biederman <ebiederm@xmission.com> Cc: Pavel Tatashin <pasha.tatashin@soleen.com> Cc: Dan Williams <dan.j.williams@intel.com> Link: http://lkml.kernel.org/r/20200508084217.9160-1-david@redhat.com Link: http://lkml.kernel.org/r/20200508084217.9160-3-david@redhat.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-04mm/memory_hotplug: handle memblocks only with CONFIG_ARCH_KEEP_MEMBLOCKDavid Hildenbrand2-10/+13
The comment in add_memory_resource() is stale: hotadd_new_pgdat() will no longer call get_pfn_range_for_nid(), as a hotadded pgdat will simply span no pages at all, until memory is moved to the zone/node via move_pfn_range_to_zone() - e.g., when onlining memory blocks. The only archs that care about memblocks for hotplugged memory (either for iterating over all system RAM or testing for memory validity) are arm64, s390x, and powerpc - due to CONFIG_ARCH_KEEP_MEMBLOCK. Without CONFIG_ARCH_KEEP_MEMBLOCK, we can simply stop messing with memblocks. Signed-off-by: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Mike Rapoport <rppt@linux.ibm.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Baoquan He <bhe@redhat.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Cc: Mike Rapoport <rppt@linux.ibm.com> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Link: http://lkml.kernel.org/r/20200422155353.25381-3-david@redhat.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-04mm/memory_hotplug: set node_start_pfn of hotadded pgdat to 0David Hildenbrand1-9/+6
Patch series "mm/memory_hotplug: handle memblocks only with CONFIG_ARCH_KEEP_MEMBLOCK", v1. A hotadded node/pgdat will span no pages at all, until memory is moved to the zone/node via move_pfn_range_to_zone() -> resize_pgdat_range - e.g., when onlining memory blocks. We don't have to initialize the node_start_pfn to the memory we are adding. This patch (of 2): Especially, there is an inconsistency: - Hotplugging memory to a memory-less node with cpus: node_start_pf == 0 - Offlining and removing last memory from a node: node_start_pfn == 0 - Hotplugging memory to a memory-less node without cpus: node_start_pfn != 0 As soon as memory is onlined, node_start_pfn is overwritten with the actual start. E.g., when adding two DIMMs but only onlining one of both, only that DIMM (with online memory blocks) is spanned by the node. Currently, the validity of node_start_pfn really is linked to node_spanned_pages != 0. With node_spanned_pages == 0 (e.g., before onlining memory), it has no meaning. So let's stop setting node_start_pfn, just to be overwritten via move_pfn_range_to_zone(). This avoids confusion when looking at the code, wondering which magic will be performed with the node_start_pfn in this function, when hotadding a pgdat. Signed-off-by: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Baoquan He <bhe@redhat.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Mike Rapoport <rppt@linux.ibm.com> Cc: Michal Hocko <mhocko@suse.com> Link: http://lkml.kernel.org/r/20200422155353.25381-1-david@redhat.com Link: http://lkml.kernel.org/r/20200422155353.25381-2-david@redhat.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-04mm/memory_hotplug: remove is_mem_section_removable()David Hildenbrand2-82/+0
Fortunately, all users of is_mem_section_removable() are gone. Get rid of it, including some now unnecessary functions. Signed-off-by: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Wei Yang <richard.weiyang@gmail.com> Reviewed-by: Baoquan He <bhe@redhat.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Oscar Salvador <osalvador@suse.de> Link: http://lkml.kernel.org/r/20200407135416.24093-3-david@redhat.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-04powerpc/pseries/hotplug-memory: stop checking is_mem_section_removable()David Hildenbrand1-23/+3
In commit 53cdc1cb29e8 ("drivers/base/memory.c: indicate all memory blocks as removable"), the user space interface to compute whether a memory block can be offlined (exposed via /sys/devices/system/memory/memoryX/removable) has effectively been deprecated. We want to remove the leftovers of the kernel implementation. When offlining a memory block (mm/memory_hotplug.c:__offline_pages()), we'll start by: 1. Testing if it contains any holes, and reject if so 2. Testing if pages belong to different zones, and reject if so 3. Isolating the page range, checking if it contains any unmovable pages Using is_mem_section_removable() before trying to offline is not only racy, it can easily result in false positives/negatives. Let's stop manually checking is_mem_section_removable(), and let device_offline() handle it completely instead. We can remove the racy is_mem_section_removable() implementation next. We now take more locks (e.g., memory hotplug lock when offlining and the zone lock when isolating), but maybe we should optimize that implementation instead if this ever becomes a real problem (after all, memory unplug is already an expensive operation). We started using is_mem_section_removable() in commit 51925fb3c5c9 ("powerpc/pseries: Implement memory hotplug remove in the kernel"), with the initial hotremove support of lmbs. Signed-off-by: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Nathan Fontenot <nfont@linux.vnet.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Baoquan He <bhe@redhat.com> Cc: Wei Yang <richard.weiyang@gmail.com> Link: http://lkml.kernel.org/r/20200407135416.24093-2-david@redhat.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-04mm/memory_hotplug: refrain from adding memory into an impossible nodeVishal Verma1-0/+5
A misbehaving qemu created a situation where the ACPI SRAT table advertised one fewer proximity domains than intended. The NFIT table did describe all the expected proximity domains. This caused the device dax driver to assign an impossible target_node to the device, and when hotplugged as system memory, this would fail with the following signature: BUG: kernel NULL pointer dereference, address: 0000000000000088 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 80000001767d4067 P4D 80000001767d4067 PUD 10e0c4067 PMD 0 Oops: 0000 [#1] SMP PTI CPU: 4 PID: 22737 Comm: kswapd3 Tainted: G O 5.6.0-rc5 #9 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014 RIP: 0010:prepare_kswapd_sleep+0x7c/0xc0 Code: 89 df e8 87 fd ff ff 89 c2 31 c0 84 d2 74 e6 0f 1f 44 00 00 48 8b 05 fb af 7a 01 48 63 93 88 1d 01 00 48 8b 84 d0 20 0f 00 00 <48> 3b 98 88 00 00 00 75 28 f0 80 a0 80 00 00 00 fe f0 80 a3 38 20 RSP: 0018:ffffc900017a3e78 EFLAGS: 00010202 RAX: 0000000000000000 RBX: ffff8881209e0000 RCX: 0000000000000000 RDX: 0000000000000003 RSI: 0000000000000000 RDI: ffff8881209e0e80 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000008000 R10: 0000000000000000 R11: 0000000000000003 R12: 0000000000000003 R13: 0000000000000003 R14: 0000000000000000 R15: ffffc900017a3ec8 FS: 0000000000000000(0000) GS:ffff888318c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000088 CR3: 0000000120b50002 CR4: 00000000001606e0 Call Trace: kswapd+0x103/0x520 kthread+0x120/0x140 ret_from_fork+0x3a/0x50 Add a check in the add_memory path to fail if the node to which we are adding memory is in the node_possible_map Signed-off-by: Vishal Verma <vishal.l.verma@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: David Hildenbrand <david@redhat.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: David Hildenbrand <david@redhat.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Link: http://lkml.kernel.org/r/20200416225438.15208-1-vishal.l.verma@intel.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-04mm: add kvfree_sensitive() for freeing sensitive data objectsWaiman Long4-22/+24
For kvmalloc'ed data object that contains sensitive information like cryptographic keys, we need to make sure that the buffer is always cleared before freeing it. Using memset() alone for buffer clearing may not provide certainty as the compiler may compile it away. To be sure, the special memzero_explicit() has to be used. This patch introduces a new kvfree_sensitive() for freeing those sensitive data objects allocated by kvmalloc(). The relevant places where kvfree_sensitive() can be used are modified to use it. Fixes: 4f0882491a14 ("KEYS: Avoid false positive ENOMEM error on key read") Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Waiman Long <longman@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Eric Biggers <ebiggers@google.com> Acked-by: David Howells <dhowells@redhat.com> Cc: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> Cc: James Morris <jmorris@namei.org> Cc: "Serge E. Hallyn" <serge@hallyn.com> Cc: Joe Perches <joe@perches.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: David Rientjes <rientjes@google.com> Cc: Uladzislau Rezki <urezki@gmail.com> Link: http://lkml.kernel.org/r/20200407200318.11711-1-longman@redhat.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>