- 16 Oct, 2020 40 commits
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git://git.kernel.org/pub/scm/linux/kernel/git/s390/linuxLinus Torvalds authored
Pull s390 updates from Vasily Gorbik: - Remove address space overrides using set_fs() - Convert to generic vDSO - Convert to generic page table dumper - Add ARCH_HAS_DEBUG_WX support - Add leap seconds handling support - Add NVMe firmware-assisted kernel dump support - Extend NVMe boot support with memory clearing control and addition of kernel parameters - AP bus and zcrypt api code rework. Add adapter configure/deconfigure interface. Extend debug features. Add failure injection support - Add ECC secure private keys support - Add KASan support for running protected virtualization host with 4-level paging - Utilize destroy page ultravisor call to speed up secure guests shutdown - Implement ioremap_wc() and ioremap_prot() with MIO in PCI code - Various checksum improvements - Other small various fixes and improvements all over the code * tag 's390-5.10-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (85 commits) s390/uaccess: fix indentation s390/uaccess: add default cases for __put_user_fn()/__get_user_fn() s390/zcrypt: fix wrong format specifications s390/kprobes: move insn_page to text segment s390/sie: fix typo in SIGP code description s390/lib: fix kernel doc for memcmp() s390/zcrypt: Introduce Failure Injection feature s390/zcrypt: move ap_msg param one level up the call chain s390/ap/zcrypt: revisit ap and zcrypt error handling s390/ap: Support AP card SCLP config and deconfig operations s390/sclp: Add support for SCLP AP adapter config/deconfig s390/ap: add card/queue deconfig state s390/ap: add error response code field for ap queue devices s390/ap: split ap queue state machine state from device state s390/zcrypt: New config switch CONFIG_ZCRYPT_DEBUG s390/zcrypt: introduce msg tracking in zcrypt functions s390/startup: correct early pgm check info formatting s390: remove orphaned extern variables declarations s390/kasan: make sure int handler always run with DAT on s390/ipl: add support to control memory clearing for nvme re-IPL ...
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git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linuxLinus Torvalds authored
Pull powerpc updates from Michael Ellerman: - A series from Nick adding ARCH_WANT_IRQS_OFF_ACTIVATE_MM & selecting it for powerpc, as well as a related fix for sparc. - Remove support for PowerPC 601. - Some fixes for watchpoints & addition of a new ptrace flag for detecting ISA v3.1 (Power10) watchpoint features. - A fix for kernels using 4K pages and the hash MMU on bare metal Power9 systems with > 16TB of RAM, or RAM on the 2nd node. - A basic idle driver for shallow stop states on Power10. - Tweaks to our sched domains code to better inform the scheduler about the hardware topology on Power9/10, where two SMT4 cores can be presented by firmware as an SMT8 core. - A series doing further reworks & cleanups of our EEH code. - Addition of a filter for RTAS (firmware) calls done via sys_rtas(), to prevent root from overwriting kernel memory. - Other smaller features, fixes & cleanups. Thanks to: Alexey Kardashevskiy, Andrew Donnellan, Aneesh Kumar K.V, Athira Rajeev, Biwen Li, Cameron Berkenpas, Cédric Le Goater, Christophe Leroy, Christoph Hellwig, Colin Ian King, Daniel Axtens, David Dai, Finn Thain, Frederic Barrat, Gautham R. Shenoy, Greg Kurz, Gustavo Romero, Ira Weiny, Jason Yan, Joel Stanley, Jordan Niethe, Kajol Jain, Konrad Rzeszutek Wilk, Laurent Dufour, Leonardo Bras, Liu Shixin, Luca Ceresoli, Madhavan Srinivasan, Mahesh Salgaonkar, Nathan Lynch, Nicholas Mc Guire, Nicholas Piggin, Nick Desaulniers, Oliver O'Halloran, Pedro Miraglia Franco de Carvalho, Pratik Rajesh Sampat, Qian Cai, Qinglang Miao, Ravi Bangoria, Russell Currey, Satheesh Rajendran, Scott Cheloha, Segher Boessenkool, Srikar Dronamraju, Stan Johnson, Stephen Kitt, Stephen Rothwell, Thiago Jung Bauermann, Tyrel Datwyler, Vaibhav Jain, Vaidyanathan Srinivasan, Vasant Hegde, Wang Wensheng, Wolfram Sang, Yang Yingliang, zhengbin. * tag 'powerpc-5.10-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (228 commits) Revert "powerpc/pci: unmap legacy INTx interrupts when a PHB is removed" selftests/powerpc: Fix eeh-basic.sh exit codes cpufreq: powernv: Fix frame-size-overflow in powernv_cpufreq_reboot_notifier powerpc/time: Make get_tb() common to PPC32 and PPC64 powerpc/time: Make get_tbl() common to PPC32 and PPC64 powerpc/time: Remove get_tbu() powerpc/time: Avoid using get_tbl() and get_tbu() internally powerpc/time: Make mftb() common to PPC32 and PPC64 powerpc/time: Rename mftbl() to mftb() powerpc/32s: Remove #ifdef CONFIG_PPC_BOOK3S_32 in head_book3s_32.S powerpc/32s: Rename head_32.S to head_book3s_32.S powerpc/32s: Setup the early hash table at all time. powerpc/time: Remove ifdef in get_dec() and set_dec() powerpc: Remove get_tb_or_rtc() powerpc: Remove __USE_RTC() powerpc: Tidy up a bit after removal of PowerPC 601. powerpc: Remove support for PowerPC 601 powerpc: Remove PowerPC 601 powerpc: Drop SYNC_601() ISYNC_601() and SYNC() powerpc: Remove CONFIG_PPC601_SYNC_FIX ...
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Linus Torvalds authored
Merge more updates from Andrew Morton: "155 patches. Subsystems affected by this patch series: mm (dax, debug, thp, readahead, page-poison, util, memory-hotplug, zram, cleanups), misc, core-kernel, get_maintainer, MAINTAINERS, lib, bitops, checkpatch, binfmt, ramfs, autofs, nilfs, rapidio, panic, relay, kgdb, ubsan, romfs, and fault-injection" * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (155 commits) lib, uaccess: add failure injection to usercopy functions lib, include/linux: add usercopy failure capability ROMFS: support inode blocks calculation ubsan: introduce CONFIG_UBSAN_LOCAL_BOUNDS for Clang sched.h: drop in_ubsan field when UBSAN is in trap mode scripts/gdb/tasks: add headers and improve spacing format scripts/gdb/proc: add struct mount & struct super_block addr in lx-mounts command kernel/relay.c: drop unneeded initialization panic: dump registers on panic_on_warn rapidio: fix the missed put_device() for rio_mport_add_riodev rapidio: fix error handling path nilfs2: fix some kernel-doc warnings for nilfs2 autofs: harden ioctl table ramfs: fix nommu mmap with gaps in the page cache mm: remove the now-unnecessary mmget_still_valid() hack mm/gup: take mmap_lock in get_dump_page() binfmt_elf, binfmt_elf_fdpic: use a VMA list snapshot coredump: rework elf/elf_fdpic vma_dump_size() into common helper coredump: refactor page range dumping into common helper coredump: let dump_emit() bail out on short writes ...
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Albert van der Linde authored
To test fault-tolerance of user memory access functions, introduce fault injection to usercopy functions. If a failure is expected return either -EFAULT or the total amount of bytes that were not copied. Signed-off-by: Albert van der Linde <alinde@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Akinobu Mita <akinobu.mita@gmail.com> Reviewed-by: Alexander Potapenko <glider@google.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andrey Konovalov <andreyknvl@google.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Borislav Petkov <bp@alien8.de> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Marco Elver <elver@google.com> Cc: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Christoph Hellwig <hch@lst.de> Link: http://lkml.kernel.org/r/20200831171733.955393-3-alinde@google.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Albert van der Linde authored
Patch series "add fault injection to user memory access", v3. The goal of this series is to improve testing of fault-tolerance in usages of user memory access functions, by adding support for fault injection. syzkaller/syzbot are using the existing fault injection modes and will use this particular feature also. The first patch adds failure injection capability for usercopy functions. The second changes usercopy functions to use this new failure capability (copy_from_user, ...). The third patch adds get/put/clear_user failures to x86. This patch (of 3): Add a failure injection capability to improve testing of fault-tolerance in usages of user memory access functions. Add CONFIG_FAULT_INJECTION_USERCOPY to enable faults in usercopy functions. The should_fail_usercopy function is to be called by these functions (copy_from_user, get_user, ...) in order to fail or not. Signed-off-by: Albert van der Linde <alinde@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Akinobu Mita <akinobu.mita@gmail.com> Reviewed-by: Alexander Potapenko <glider@google.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andrey Konovalov <andreyknvl@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Marco Elver <elver@google.com> Cc: Christoph Hellwig <hch@lst.de> Link: http://lkml.kernel.org/r/20200831171733.955393-1-alinde@google.com Link: http://lkml.kernel.org/r/20200831171733.955393-2-alinde@google.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Libing Zhou authored
When use 'stat' tool to display file status, the 'Blocks' field always in '0', this is not good for tool 'du'(e.g.: busybox 'du'), it always output '0' size for the files under ROMFS since such tool calculates number of 512B Blocks. This patch calculates approx. number of 512B blocks based on inode size. Signed-off-by: Libing Zhou <libing.zhou@nokia-sbell.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: David Howells <dhowells@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Link: http://lkml.kernel.org/r/20200811052606.4243-1-libing.zhou@nokia-sbell.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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George Popescu authored
When the kernel is compiled with Clang, -fsanitize=bounds expands to -fsanitize=array-bounds and -fsanitize=local-bounds. Enabling -fsanitize=local-bounds with Clang has the unfortunate side-effect of inserting traps; this goes back to its original intent, which was as a hardening and not a debugging feature [1]. The same feature made its way into -fsanitize=bounds, but the traps remained. For that reason, -fsanitize=bounds was split into 'array-bounds' and 'local-bounds' [2]. Since 'local-bounds' doesn't behave like a normal sanitizer, enable it with Clang only if trapping behaviour was requested by CONFIG_UBSAN_TRAP=y. Add the UBSAN_BOUNDS_LOCAL config to Kconfig.ubsan to enable the 'local-bounds' option by default when UBSAN_TRAP is enabled. [1] http://lists.llvm.org/pipermail/llvm-dev/2012-May/049972.html [2] http://lists.llvm.org/pipermail/cfe-commits/Week-of-Mon-20131021/091536.htmlSuggested-by: Marco Elver <elver@google.com> Signed-off-by: George Popescu <georgepope@android.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: David Brazdil <dbrazdil@google.com> Reviewed-by: Marco Elver <elver@google.com> Cc: Masahiro Yamada <masahiroy@kernel.org> Cc: Michal Marek <michal.lkml@markovi.net> Cc: Nathan Chancellor <natechancellor@gmail.com> Cc: Nick Desaulniers <ndesaulniers@google.com> Cc: Kees Cook <keescook@chromium.org> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: https://lkml.kernel.org/r/20200922074330.2549523-1-georgepope@google.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Elena Petrova authored
in_ubsan field of task_struct is only used in lib/ubsan.c, which in its turn is used only `ifneq ($(CONFIG_UBSAN_TRAP),y)`. Removing unnecessary field from a task_struct will help preserve the ABI between vanilla and CONFIG_UBSAN_TRAP'ed kernels. In particular, this will help enabling bounds sanitizer transparently for Android's GKI. Signed-off-by: Elena Petrova <lenaptr@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Kees Cook <keescook@chromium.org> Cc: Jann Horn <jannh@google.com> Link: https://lkml.kernel.org/r/20200910134802.3160311-1-lenaptr@google.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Ritesh Harjani authored
With the patch. <e.g. o/p> TASK PID COMM 0xffffffff82c2b8c0 0 swapper/0 0xffff888a0ba20040 1 systemd 0xffff888a0ba24040 2 kthreadd 0xffff888a0ba28040 3 rcu_gp w/o 0xffffffff82c2b8c0 <init_task> 0 swapper/0 0xffff888a0ba20040 1 systemd 0xffff888a0ba24040 2 kthreadd 0xffff888a0ba28040 3 rcu_gp Signed-off-by: Ritesh Harjani <riteshh@linux.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Jan Kiszka <jan.kiszka@siemens.com> Cc: Kieran Bingham <kbingham@kernel.org> Link: http://lkml.kernel.org/r/54c868c79b5fc364a8be7799891934a6fe6d1464.1597742951.git.riteshh@linux.ibm.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Ritesh Harjani authored
This is many times found useful while debugging some FS related issue. <e.g. output> mount super_block devname pathname fstype options 0xffff888a0bfa4b40 0xffff888a0bfc1000 none / rootfs rw 0 0 0xffff888a033f75c0 0xffff8889fcf65000 /dev/root / ext4 rw,relatime 0 0 0xffff8889fc8ce040 0xffff888a0bb51000 devtmpfs /dev devtmpfs rw,relatime 0 0 Signed-off-by: Ritesh Harjani <riteshh@linux.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Jan Kiszka <jan.kiszka@siemens.com> Cc: Kieran Bingham <kbingham@kernel.org> Link: http://lkml.kernel.org/r/a3c4177e1597b3e06d66d55e07d72c0c46a03571.1597742951.git.riteshh@linux.ibm.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Sudip Mukherjee authored
The variable 'consumed' is initialized with the consumed count but immediately after that the consumed count is updated and assigned to 'consumed' again thus overwriting the previous value. So, drop the unneeded initialization. Signed-off-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Link: https://lkml.kernel.org/r/20201005205727.1147-1-sudipm.mukherjee@gmail.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Alexey Kardashevskiy authored
Currently we print stack and registers for ordinary warnings but we do not for panic_on_warn which looks as oversight - panic() will reboot the machine but won't print registers. This moves printing of registers and modules earlier. This does not move the stack dumping as panic() dumps it. Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Kees Cook <keescook@chromium.org> Cc: Douglas Anderson <dianders@chromium.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Kees Cook <keescook@chromium.org> Cc: Rafael Aquini <aquini@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Deacon <will@kernel.org> Cc: Nicholas Piggin <npiggin@gmail.com> Link: https://lkml.kernel.org/r/20200804095054.68724-1-aik@ozlabs.ruSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Jing Xiangfeng authored
rio_mport_add_riodev() misses to call put_device() when the device already exists. Add the missed function call to fix it. Fixes: e8de3701 ("rapidio: add mport char device driver") Signed-off-by: Jing Xiangfeng <jingxiangfeng@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Dan Carpenter <dan.carpenter@oracle.com> Cc: Matt Porter <mporter@kernel.crashing.org> Cc: Alexandre Bounine <alex.bou9@gmail.com> Cc: Gustavo A. R. Silva <gustavoars@kernel.org> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Kees Cook <keescook@chromium.org> Cc: Madhuparna Bhowmik <madhuparnabhowmik10@gmail.com> Link: https://lkml.kernel.org/r/20200922072525.42330-1-jingxiangfeng@huawei.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Souptick Joarder authored
rio_dma_transfer() attempts to clamp the return value of pin_user_pages_fast() to be >= 0. However, the attempt fails because nr_pages is overridden a few lines later, and restored to the undesirable -ERRNO value. The return value is ultimately stored in nr_pages, which in turn is passed to unpin_user_pages(), which expects nr_pages >= 0, else, disaster. Fix this by fixing the nesting of the assignment to nr_pages: nr_pages should be clamped to zero if pin_user_pages_fast() returns -ERRNO, or set to the return value of pin_user_pages_fast(), otherwise. [jhubbard@nvidia.com: new changelog] Fixes: e8de3701 ("rapidio: add mport char device driver") Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Reviewed-by: John Hubbard <jhubbard@nvidia.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Matt Porter <mporter@kernel.crashing.org> Cc: Alexandre Bounine <alex.bou9@gmail.com> Cc: Gustavo A. R. Silva <gustavoars@kernel.org> Cc: Madhuparna Bhowmik <madhuparnabhowmik10@gmail.com> Cc: Dan Carpenter <dan.carpenter@oracle.com> Link: https://lkml.kernel.org/r/1600227737-20785-1-git-send-email-jrdr.linux@gmail.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Wang Hai authored
Fixes the following W=1 kernel build warning(s): fs/nilfs2/bmap.c:378: warning: Excess function parameter 'bhp' description in 'nilfs_bmap_assign' fs/nilfs2/cpfile.c:907: warning: Excess function parameter 'status' description in 'nilfs_cpfile_change_cpmode' fs/nilfs2/cpfile.c:946: warning: Excess function parameter 'stat' description in 'nilfs_cpfile_get_stat' fs/nilfs2/page.c:76: warning: Excess function parameter 'inode' description in 'nilfs_forget_buffer' fs/nilfs2/sufile.c:563: warning: Excess function parameter 'stat' description in 'nilfs_sufile_get_stat' Signed-off-by: Wang Hai <wanghai38@huawei.com> Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Link: https://lkml.kernel.org/r/1601386269-2423-1-git-send-email-konishi.ryusuke@gmail.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Matthew Wilcox authored
The table of ioctl functions should be marked const in order to put them in read-only memory, and we should use array_index_nospec() to avoid speculation disclosing the contents of kernel memory to userspace. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Ian Kent <raven@themaw.net> Link: https://lkml.kernel.org/r/20200818122203.GO17456@casper.infradead.orgSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Matthew Wilcox (Oracle) authored
ramfs needs to check that pages are both physically contiguous and contiguous in the file. If the page cache happens to have, eg, page A for index 0 of the file, no page for index 1, and page A+1 for index 2, then an mmap of the first two pages of the file will succeed when it should fail. Fixes: 642fb4d1 ("[PATCH] NOMMU: Provide shared-writable mmap support on ramfs") Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: David Howells <dhowells@redhat.com> Link: https://lkml.kernel.org/r/20200914122239.GO6583@casper.infradead.orgSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Jann Horn authored
The preceding patches have ensured that core dumping properly takes the mmap_lock. Thanks to that, we can now remove mmget_still_valid() and all its users. Signed-off-by: Jann Horn <jannh@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Christoph Hellwig <hch@lst.de> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: "Eric W . Biederman" <ebiederm@xmission.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Hugh Dickins <hughd@google.com> Link: http://lkml.kernel.org/r/20200827114932.3572699-8-jannh@google.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Jann Horn authored
Properly take the mmap_lock before calling into the GUP code from get_dump_page(); and play nice, allowing the GUP code to drop the mmap_lock if it has to sleep. As Linus pointed out, we don't actually need the VMA because __get_user_pages() will flush the dcache for us if necessary. Signed-off-by: Jann Horn <jannh@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Christoph Hellwig <hch@lst.de> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: "Eric W . Biederman" <ebiederm@xmission.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Hugh Dickins <hughd@google.com> Link: http://lkml.kernel.org/r/20200827114932.3572699-7-jannh@google.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Jann Horn authored
In both binfmt_elf and binfmt_elf_fdpic, use a new helper dump_vma_snapshot() to take a snapshot of the VMA list (including the gate VMA, if we have one) while protected by the mmap_lock, and then use that snapshot instead of walking the VMA list without locking. An alternative approach would be to keep the mmap_lock held across the entire core dumping operation; however, keeping the mmap_lock locked while we may be blocked for an unbounded amount of time (e.g. because we're dumping to a FUSE filesystem or so) isn't really optimal; the mmap_lock blocks things like the ->release handler of userfaultfd, and we don't really want critical system daemons to grind to a halt just because someone "gifted" them SCM_RIGHTS to an eternally-locked userfaultfd, or something like that. Since both the normal ELF code and the FDPIC ELF code need this functionality (and if any other binfmt wants to add coredump support in the future, they'd probably need it, too), implement this with a common helper in fs/coredump.c. A downside of this approach is that we now need a bigger amount of kernel memory per userspace VMA in the normal ELF case, and that we need O(n) kernel memory in the FDPIC ELF case at all; but 40 bytes per VMA shouldn't be terribly bad. There currently is a data race between stack expansion and anything that reads ->vm_start or ->vm_end under the mmap_lock held in read mode; to mitigate that for core dumping, take the mmap_lock in write mode when taking a snapshot of the VMA hierarchy. (If we only took the mmap_lock in read mode, we could end up with a corrupted core dump if someone does get_user_pages_remote() concurrently. Not really a major problem, but taking the mmap_lock either way works here, so we might as well avoid the issue.) (This doesn't do anything about the existing data races with stack expansion in other mm code.) Signed-off-by: Jann Horn <jannh@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Christoph Hellwig <hch@lst.de> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: "Eric W . Biederman" <ebiederm@xmission.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Hugh Dickins <hughd@google.com> Link: http://lkml.kernel.org/r/20200827114932.3572699-6-jannh@google.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Jann Horn authored
At the moment, the binfmt_elf and binfmt_elf_fdpic code have slightly different code to figure out which VMAs should be dumped, and if so, whether the dump should contain the entire VMA or just its first page. Eliminate duplicate code by reworking the binfmt_elf version into a generic core dumping helper in coredump.c. As part of that, change the heuristic for detecting executable/library header pages to check whether the inode is executable instead of looking at the file mode. This is less problematic in terms of locking because it lets us avoid get_user() under the mmap_sem. (And arguably it looks nicer and makes more sense in generic code.) Adjust a little bit based on the binfmt_elf_fdpic version: ->anon_vma is only meaningful under CONFIG_MMU, otherwise we have to assume that the VMA has been written to. Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Jann Horn <jannh@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Christoph Hellwig <hch@lst.de> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: "Eric W . Biederman" <ebiederm@xmission.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Hugh Dickins <hughd@google.com> Link: http://lkml.kernel.org/r/20200827114932.3572699-5-jannh@google.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Jann Horn authored
Both fs/binfmt_elf.c and fs/binfmt_elf_fdpic.c need to dump ranges of pages into the coredump file. Extract that logic into a common helper. Signed-off-by: Jann Horn <jannh@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Christoph Hellwig <hch@lst.de> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: "Eric W . Biederman" <ebiederm@xmission.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Hugh Dickins <hughd@google.com> Link: http://lkml.kernel.org/r/20200827114932.3572699-4-jannh@google.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Jann Horn authored
dump_emit() has a retry loop, but there seems to be no way for that retry logic to actually be used; and it was also buggy, writing the same data repeatedly after a short write. Let's just bail out on a short write. Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Jann Horn <jannh@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Christoph Hellwig <hch@lst.de> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: "Eric W . Biederman" <ebiederm@xmission.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Hugh Dickins <hughd@google.com> Link: http://lkml.kernel.org/r/20200827114932.3572699-3-jannh@google.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Jann Horn authored
Patch series "Fix ELF / FDPIC ELF core dumping, and use mmap_lock properly in there", v5. At the moment, we have that rather ugly mmget_still_valid() helper to work around <https://crbug.com/project-zero/1790>: ELF core dumping doesn't take the mmap_sem while traversing the task's VMAs, and if anything (like userfaultfd) then remotely messes with the VMA tree, fireworks ensue. So at the moment we use mmget_still_valid() to bail out in any writers that might be operating on a remote mm's VMAs. With this series, I'm trying to get rid of the need for that as cleanly as possible. ("cleanly" meaning "avoid holding the mmap_lock across unbounded sleeps".) Patches 1, 2, 3 and 4 are relatively unrelated cleanups in the core dumping code. Patches 5 and 6 implement the main change: Instead of repeatedly accessing the VMA list with sleeps in between, we snapshot it at the start with proper locking, and then later we just use our copy of the VMA list. This ensures that the kernel won't crash, that VMA metadata in the coredump is consistent even in the presence of concurrent modifications, and that any virtual addresses that aren't being concurrently modified have their contents show up in the core dump properly. The disadvantage of this approach is that we need a bit more memory during core dumping for storing metadata about all VMAs. At the end of the series, patch 7 removes the old workaround for this issue (mmget_still_valid()). I have tested: - Creating a simple core dump on X86-64 still works. - The created coredump on X86-64 opens in GDB and looks plausible. - X86-64 core dumps contain the first page for executable mappings at offset 0, and don't contain the first page for non-executable file mappings or executable mappings at offset !=0. - NOMMU 32-bit ARM can still generate plausible-looking core dumps through the FDPIC implementation. (I can't test this with GDB because GDB is missing some structure definition for nommu ARM, but I've poked around in the hexdump and it looked decent.) This patch (of 7): dump_emit() is for kernel pointers, and VMAs describe userspace memory. Let's be tidy here and avoid accessing userspace pointers under KERNEL_DS, even if it probably doesn't matter much on !MMU systems - especially given that it looks like we can just use the same get_dump_page() as on MMU if we move it out of the CONFIG_MMU block. One small change we have to make in get_dump_page() is to use __get_user_pages_locked() instead of __get_user_pages(), since the latter doesn't exist on nommu. On mmu builds, __get_user_pages_locked() will just call __get_user_pages() for us. Signed-off-by: Jann Horn <jannh@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Christoph Hellwig <hch@lst.de> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: "Eric W . Biederman" <ebiederm@xmission.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Hugh Dickins <hughd@google.com> Link: http://lkml.kernel.org/r/20200827114932.3572699-1-jannh@google.com Link: http://lkml.kernel.org/r/20200827114932.3572699-2-jannh@google.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Chris Kennelly authored
This produces a PIE binary with a variety of p_align requirements, suitable for verifying that the load address meets that alignment requirement. Signed-off-by: Chris Kennelly <ckennelly@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Shuah Khan <shuah@kernel.org> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: David Rientjes <rientjes@google.com> Cc: Fangrui Song <maskray@google.com> Cc: Hugh Dickens <hughd@google.com> Cc: Ian Rogers <irogers@google.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Nick Desaulniers <ndesaulniers@google.com> Cc: Sandeep Patil <sspatil@google.com> Cc: Song Liu <songliubraving@fb.com> Cc: Suren Baghdasaryan <surenb@google.com> Link: https://lkml.kernel.org/r/20200820170541.1132271-3-ckennelly@google.com Link: https://lkml.kernel.org/r/20200821233848.3904680-3-ckennelly@google.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Chris Kennelly authored
Patch series "Selecting Load Addresses According to p_align", v3. The current ELF loading mechancism provides page-aligned mappings. This can lead to the program being loaded in a way unsuitable for file-backed, transparent huge pages when handling PIE executables. While specifying -z,max-page-size=0x200000 to the linker will generate suitably aligned segments for huge pages on x86_64, the executable needs to be loaded at a suitably aligned address as well. This alignment requires the binary's cooperation, as distinct segments need to be appropriately paddded to be eligible for THP. For binaries built with increased alignment, this limits the number of bits usable for ASLR, but provides some randomization over using fixed load addresses/non-PIE binaries. This patch (of 2): The current ELF loading mechancism provides page-aligned mappings. This can lead to the program being loaded in a way unsuitable for file-backed, transparent huge pages when handling PIE executables. For binaries built with increased alignment, this limits the number of bits usable for ASLR, but provides some randomization over using fixed load addresses/non-PIE binaries. Tested by verifying program with -Wl,-z,max-page-size=0x200000 loading. [akpm@linux-foundation.org: fix max() warning] [ckennelly@google.com: augment comment] Link: https://lkml.kernel.org/r/20200821233848.3904680-2-ckennelly@google.comSigned-off-by: Chris Kennelly <ckennelly@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Song Liu <songliubraving@fb.com> Cc: David Rientjes <rientjes@google.com> Cc: Ian Rogers <irogers@google.com> Cc: Hugh Dickens <hughd@google.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Sandeep Patil <sspatil@google.com> Cc: Fangrui Song <maskray@google.com> Cc: Nick Desaulniers <ndesaulniers@google.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Shuah Khan <shuah@kernel.org> Link: https://lkml.kernel.org/r/20200820170541.1132271-1-ckennelly@google.com Link: https://lkml.kernel.org/r/20200820170541.1132271-2-ckennelly@google.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Dwaipayan Ray authored
The author signed-off-by checks are currently very vague. Cases like same name or same address are not handled separately. For example, running checkpatch on commit be6577af ("parisc: Add atomic64_set_release() define to avoid CPU soft lockups"), gives: WARNING: Missing Signed-off-by: line by nominal patch author 'John David Anglin <dave.anglin@bell.net>' The signoff line was: "Signed-off-by: Dave Anglin <dave.anglin@bell.net>" Clearly the author has signed off but with a slightly different version of his name. A more appropriate warning would have been to point out at the name mismatch instead. Previously, the values assumed by $authorsignoff were either 0 or 1 to indicate whether a proper sign off by author is present. Extended the checks to handle four new cases. $authorsignoff values now denote the following: 0: Missing sign off by patch author. 1: Sign off present and identical. 2: Addresses and names match, but comments differ. "James Watson(JW) <james@gmail.com>", "James Watson <james@gmail.com>" 3: Addresses match, but names are different. "James Watson <james@gmail.com>", "James <james@gmail.com>" 4: Names match, but addresses are different. "James Watson <james@watson.com>", "James Watson <james@gmail.com>" 5: Names match, addresses excluding subaddress details (RFC 5233) match. "James Watson <james@gmail.com>", "James Watson <james+a@gmail.com>" Also introduced a new message type FROM_SIGN_OFF_MISMATCH for cases 2, 3, 4 and 5. Suggested-by: Joe Perches <joe@perches.com> Signed-off-by: Dwaipayan Ray <dwaipayanray1@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Joe Perches <joe@perches.com> Link: https://lore.kernel.org/linux-kernel-mentees/c1ca28e77e8e3bfa7aadf3efa8ed70f97a9d369c.camel@perches.com/ Link: https://lkml.kernel.org/r/20201007192029.551744-1-dwaipayanray1@gmail.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Łukasz Stelmach authored
To avoid false positives in presence of SPDX-License-Identifier in networking files it is required to increase the leeway for empty block comment lines by one line. For example, checking drivers/net/loopback.c which starts with // SPDX-License-Identifier: GPL-2.0-or-later /* * INET An implementation of the TCP/IP protocol suite for the LINUX rsults in an unnecessary warning WARNING: networking block comments don't use an empty /* line, use /* Comment... +/* + * INET An implementation of the TCP/IP protocol suite for the LINUX Signed-off-by: Łukasz Stelmach <l.stelmach@samsung.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Joe Perches <joe@perches.com> Cc: Bartłomiej Żolnierkiewicz <b.zolnierkie@samsung.co> Cc: Marek Szyprowski <m.szyprowski@samsung.com> Link: https://lkml.kernel.org/r/20201006083509.19934-1-l.stelmach@samsung.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Dwaipayan Ray authored
Checkpatch.pl doesn't have a check for excluding while (...) {...} blocks from MULTISTATEMENT_MACRO_USE_DO_WHILE error. For example, running checkpatch.pl on the file mm/maccess.c in the kernel generates the following error: ERROR: Macros with complex values should be enclosed in parentheses +#define copy_from_kernel_nofault_loop(dst, src, len, type, err_label) \ + while (len >= sizeof(type)) { \ + __get_kernel_nofault(dst, src, type, err_label); \ + dst += sizeof(type); \ + src += sizeof(type); \ + len -= sizeof(type); \ + } The error is misleading for this case. Enclosing it in parentheses doesn't make any sense. Checkpatch already has an exception list for such common macro types. Added a new exception for while (...) {...} style blocks to the same. In addition, the brace flatten logic was modified by changing the substitution characters from "1" to "1u". This was done to ensure that macros in the form "#define foo(bar) while(bar){bar--;}" were also correctly procecssed. Link: https://lore.kernel.org/linux-kernel-mentees/dc985938aa3986702815a0bd68dfca8a03c85447.camel@perches.com/Suggested-by: Joe Perches <joe@perches.com> Signed-off-by: Dwaipayan Ray <dwaipayanray1@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Link: https://lkml.kernel.org/r/20201001171903.312021-1-dwaipayanray1@gmail.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Joe Perches authored
Embedding the complete filename path inside the file isn't particularly useful as often the path is moved around and becomes incorrect. Emit a warning when the source contains the filename. [akpm@linux-foundation.org: remove stray " di"] Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Link: https://lkml.kernel.org/r/1fd5f9188a14acdca703ca00301ee323de672a8d.camel@perches.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Dwaipayan Ray authored
Checkpatch did not handle cases where the author From: header was split into multiple lines. The author identity could not be resolved and checkpatch generated a false NO_AUTHOR_SIGN_OFF warning. A typical example is commit e33bcbab ("tee: add support for session's client UUID generation"). When checkpatch was run on this commit, it displayed: "WARNING:NO_AUTHOR_SIGN_OFF: Missing Signed-off-by: line by nominal patch author ''" This was due to split header lines not being handled properly and the author himself wrote in commit cd261496 ("checkpatch: warn if missing author Signed-off-by"): "Split From: headers are not fully handled: only the first part is compared." Support split From: headers by correctly parsing the header extension lines. RFC 5322, Section-2.2.3 stated that each extended line must start with a WSP character (a space or htab). The solution was therefore to concatenate the lines which start with a WSP to get the correct long header. Suggested-by: Joe Perches <joe@perches.com> Signed-off-by: Dwaipayan Ray <dwaipayanray1@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Tested-by: Lukas Bulwahn <lukas.bulwahn@gmail.com> Reviewed-by: Lukas Bulwahn <lukas.bulwahn@gmail.com> Acked-by: Joe Perches <joe@perches.com> Link: https://lore.kernel.org/linux-kernel-mentees/f5d8124e54a50480b0a9fa638787bc29b6e09854.camel@perches.com/ Link: https://lkml.kernel.org/r/20200921085436.63003-1-dwaipayanray1@gmail.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Joe Perches authored
If a file exists in git and checkpatch is used without the -f flag for scanning a file, then checkpatch will scan the file assuming it's a patch and emit: ERROR: Does not appear to be a unified-diff format patch Change the behavior to assume the -f flag if the file exists in git. [joe@perches.com: fix git "fatal" warning if file argument outside kernel tree] Link: https://lkml.kernel.org/r/b6afa04112d450c2fc120a308d706acd60cee294.camel@perches.comSigned-off-by: Joe Perches <joe@perches.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Julia Lawall <julia.lawall@inria.fr> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Link: https://lkml.kernel.org/r/45b81a48e1568bd0126a96f5046eb7aaae9b83c9.camel@perches.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Joe Perches authored
The uninitialized_var() macro was removed recently via commit 63a0895d ("compiler: Remove uninitialized_var() macro") as it's not a particularly useful warning and its use can "paper over real bugs". Add a checkpatch test to warn on self-assignments as a means to avoid compiler warnings and as a back-door mechanism to reproduce the old uninitialized_var macro behavior. [akpm@linux-foundation.org: coding style fixes] Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Kees Cook <keescook@chromium.org> Cc: Gustavo A. R. Silva <gustavoars@kernel.org> Cc: Denis Efremov <efremov@linux.com> Cc: Julia Lawall <julia.lawall@inria.fr> Link: https://lkml.kernel.org/r/afc2cffdd315d3e4394af149278df9e8af7f49f4.camel@perches.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Rikard Falkeborn authored
All usages of include/linux of these are const pointers, and all instances in the kernel except one, that are not const can be made const (patches have been posted for those separately). Signed-off-by: Rikard Falkeborn <rikard.falkeborn@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Acked-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org> Cc: Joe Perches <joe@perches.com> Cc: Andreas Färber <afaerber@suse.de> Cc: Rikard Falkeborn <rikard.falkeborn@gmail.com> Link: https://lkml.kernel.org/r/20200830224352.37114-1-rikard.falkeborn@gmail.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Nicolas Boichat authored
trace_printk is meant as a debugging tool, and should not be compiled into production code without specific debug Kconfig options enabled, or source code changes, as indicated by the warning that shows up on boot if any trace_printk is called: ** NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE ** ** ** ** trace_printk() being used. Allocating extra memory. ** ** ** ** This means that this is a DEBUG kernel and it is ** ** unsafe for production use. ** Let's warn developers when they try to submit such a change. Signed-off-by: Nicolas Boichat <drinkcat@chromium.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Joe Perches <joe@perches.com> Link: https://lkml.kernel.org/r/20200825193600.v2.1.I723c43c155f02f726c97501be77984f1e6bb740a@changeidSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Rikard Falkeborn authored
All usages of phy_ops in include/linux uses const phy_ops * and all instances of phy_ops in the kernel that are not const already can be made const (patches have been posted for those separately). Suggested-by: Joe Perches <joe@perches.com> Signed-off-by: Rikard Falkeborn <rikard.falkeborn@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Kishon Vijay Abraham I <kishon@ti.com> Cc: Vinod Koul <vkoul@kernel.org> Link: https://lkml.kernel.org/r/20200824214132.9072-1-rikard.falkeborn@gmail.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Joe Perches authored
There are commas used as statement terminations that should typically have used semicolons instead. Only direct assignments or use of a single function or value on a single line are detected by this test. e.g.: foo = bar(), /* typical use is semicolon not comma */ bar = baz(); Add an imperfect test to detect these comma uses. No false positives were found in testing, but many types of false negatives are possible. e.g.: foo = bar() + 1, /* comma use, but not direct assignment */ bar = baz(); Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Link: https://lkml.kernel.org/r/3bf27caf462007dfa75647b040ab3191374a59de.camel@perches.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Joe Perches authored
Currently this test only works on .[ch] files. Move the test to check more file types and the commit log. Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/180b3b5677771c902b2e2f7a2b7090ede65fe004.camel@perches.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Jerome Forissier authored
Kconfig allows to customize the CONFIG_ prefix via the $CONFIG_ environment variable. Out-of-tree projects may therefore use Kconfig with a different prefix, or they may use a custom configuration tool which does not use the CONFIG_ prefix at all. Such projects may still want to adhere to the Linux kernel coding style and run checkpatch.pl. One example is OP-TEE [1] which does not use Kconfig but does have configuration options prefixed with CFG_. It also mostly follows the kernel coding style and therefore being able to use checkpatch is quite valuable. To make this possible, add the --kconfig-prefix command line option. [1] https://github.com/OP-TEE/optee_osSigned-off-by: Jerome Forissier <jerome@forissier.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Joe Perches <joe@perches.com> Link: http://lkml.kernel.org/r/20200818081732.800449-1-jerome@forissier.orgSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Wei Yang authored
These two functions share the same logic. Signed-off-by: Wei Yang <richard.weiyang@linux.alibaba.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Christian Brauner <christian.brauner@ubuntu.com> Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lkml.kernel.org/r/20200807085837.11697-3-richard.weiyang@linux.alibaba.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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