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2021-02-24Merge tag 'x86-entry-2021-02-24' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 irq entry updates from Thomas Gleixner: "The irq stack switching was moved out of the ASM entry code in course of the entry code consolidation. It ended up being suboptimal in various ways. This reworks the X86 irq stack handling: - Make the stack switching inline so the stackpointer manipulation is not longer at an easy to find place. - Get rid of the unnecessary indirect call. - Avoid the double stack switching in interrupt return and reuse the interrupt stack for softirq handling. - A objtool fix for CONFIG_FRAME_POINTER=y builds where it got confused about the stack pointer manipulation" * tag 'x86-entry-2021-02-24' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: objtool: Fix stack-swizzle for FRAME_POINTER=y um: Enforce the usage of asm-generic/softirq_stack.h x86/softirq/64: Inline do_softirq_own_stack() softirq: Move do_softirq_own_stack() to generic asm header softirq: Move __ARCH_HAS_DO_SOFTIRQ to Kconfig x86: Select CONFIG_HAVE_IRQ_EXIT_ON_IRQ_STACK x86/softirq: Remove indirection in do_softirq_own_stack() x86/entry: Use run_sysvec_on_irqstack_cond() for XEN upcall x86/entry: Convert device interrupts to inline stack switching x86/entry: Convert system vectors to irq stack macro x86/irq: Provide macro for inlining irq stack switching x86/apic: Split out spurious handling code x86/irq/64: Adjust the per CPU irq stack pointer by 8 x86/irq: Sanitize irq stack tracking x86/entry: Fix instrumentation annotation
2021-02-23Merge tag 'clang-lto-v5.12-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux Pull clang LTO updates from Kees Cook: "Clang Link Time Optimization. This is built on the work done preparing for LTO by arm64 folks, tracing folks, etc. This includes the core changes as well as the remaining pieces for arm64 (LTO has been the default build method on Android for about 3 years now, as it is the prerequisite for the Control Flow Integrity protections). While x86 LTO enablement is done, it depends on some pending objtool clean-ups. It's possible that I'll send a "part 2" pull request for LTO that includes x86 support. For merge log posterity, and as detailed in commit dc5723b02e52 ("kbuild: add support for Clang LTO"), here is the lt;dr to do an LTO build: make LLVM=1 LLVM_IAS=1 defconfig scripts/config -e LTO_CLANG_THIN make LLVM=1 LLVM_IAS=1 (To do a cross-compile of arm64, add "CROSS_COMPILE=aarch64-linux-gnu-" and "ARCH=arm64" to the "make" command lines.) Summary: - Clang LTO build infrastructure and arm64-specific enablement (Sami Tolvanen) - Recursive build CC_FLAGS_LTO fix (Alexander Lobakin)" * tag 'clang-lto-v5.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: kbuild: prevent CC_FLAGS_LTO self-bloating on recursive rebuilds arm64: allow LTO to be selected arm64: disable recordmcount with DYNAMIC_FTRACE_WITH_REGS arm64: vdso: disable LTO drivers/misc/lkdtm: disable LTO for rodata.o efi/libstub: disable LTO scripts/mod: disable LTO for empty.c modpost: lto: strip .lto from module names PCI: Fix PREL32 relocations for LTO init: lto: fix PREL32 relocations init: lto: ensure initcall ordering kbuild: lto: add a default list of used symbols kbuild: lto: merge module sections kbuild: lto: limit inlining kbuild: lto: fix module versioning kbuild: add support for Clang LTO tracing: move function tracer options to Kconfig
2021-02-22Merge tag 'docs-5.12' of git://git.lwn.net/linuxLinus Torvalds
Pull documentation updates from Jonathan Corbet: "It has been a relatively quiet cycle in docsland. - As promised, the minimum Sphinx version to build the docs is now 1.7, and we have dropped support for Python 2 entirely. That allowed the removal of a bunch of compatibility code. - A set of treewide warning fixups from Mauro that I applied after it became clear nobody else was going to deal with them. - The automarkup mechanism can now create cross-references from relative paths to RST files. - More translations, typo fixes, and warning fixes" * tag 'docs-5.12' of git://git.lwn.net/linux: (75 commits) docs: kernel-hacking: be more civil docs: Remove the Microsoft rhetoric Documentation/admin-guide: kernel-parameters: Update nohlt section doc/admin-guide: fix spelling mistake: "perfomance" -> "performance" docs: Document cross-referencing using relative path docs: Enable usage of relative paths to docs on automarkup docs: thermal: fix spelling mistakes Documentation: admin-guide: Update kvm/xen config option docs: Make syscalls' helpers naming consistent coding-style.rst: Avoid comma statements Documentation: /proc/loadavg: add 3 more field descriptions Documentation/submitting-patches: Add blurb about backtraces in commit messages Docs: drop Python 2 support Move our minimum Sphinx version to 1.7 Documentation: input: define ABS_PRESSURE/ABS_MT_PRESSURE resolution as grams scripts/kernel-doc: add internal hyperlink to DOC: sections Update Documentation/admin-guide/sysctl/fs.rst docs: Update DTB format references docs: zh_CN: add iio index.rst translation docs/zh_CN: add iio ep93xx_adc.rst translation ...
2021-02-21Merge tag 's390-5.12-1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux Pull s390 updates from Vasily Gorbik: - Convert to using the generic entry infrastructure. - Add vdso time namespace support. - Switch s390 and alpha to 64-bit ino_t. As discussed at https://lore.kernel.org/linux-mm/YCV7QiyoweJwvN+m@osiris/ - Get rid of expensive stck (store clock) usages where possible. Utilize cpu alternatives to patch stckf when supported. - Make tod_clock usage less error prone by converting it to a union and rework code which is using it. - Machine check handler fixes and cleanups. - Drop couple of minor inline asm optimizations to fix clang build. - Default configs changes notably to make libvirt happy. - Various changes to rework and improve qdio code. - Other small various fixes and improvements all over the code. * tag 's390-5.12-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (68 commits) s390/qdio: remove 'merge_pending' mechanism s390/qdio: improve handling of PENDING buffers for QEBSM devices s390/qdio: rework q->qdio_error indication s390/qdio: inline qdio_kick_handler() s390/time: remove get_tod_clock_ext() s390/crypto: use store_tod_clock_ext() s390/hypfs: use store_tod_clock_ext() s390/debug: use union tod_clock s390/kvm: use union tod_clock s390/vdso: use union tod_clock s390/time: convert tod_clock_base to union s390/time: introduce new store_tod_clock_ext() s390/time: rename store_tod_clock_ext() and use union tod_clock s390/time: introduce union tod_clock s390,alpha: switch to 64-bit ino_t s390: split cleanup_sie s390: use r13 in cleanup_sie as temp register s390: fix kernel asce loading when sie is interrupted s390: add stack for machine check handler s390: use WRITE_ONCE when re-allocating async stack ...
2021-02-21Merge tag 'sched-core-2021-02-17' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler updates from Ingo Molnar: "Core scheduler updates: - Add CONFIG_PREEMPT_DYNAMIC: this in its current form adds the preempt=none/voluntary/full boot options (default: full), to allow distros to build a PREEMPT kernel but fall back to close to PREEMPT_VOLUNTARY (or PREEMPT_NONE) runtime scheduling behavior via a boot time selection. There's also the /debug/sched_debug switch to do this runtime. This feature is implemented via runtime patching (a new variant of static calls). The scope of the runtime patching can be best reviewed by looking at the sched_dynamic_update() function in kernel/sched/core.c. ( Note that the dynamic none/voluntary mode isn't 100% identical, for example preempt-RCU is available in all cases, plus the preempt count is maintained in all models, which has runtime overhead even with the code patching. ) The PREEMPT_VOLUNTARY/PREEMPT_NONE models, used by the vast majority of distributions, are supposed to be unaffected. - Fix ignored rescheduling after rcu_eqs_enter(). This is a bug that was found via rcutorture triggering a hang. The bug is that rcu_idle_enter() may wake up a NOCB kthread, but this happens after the last generic need_resched() check. Some cpuidle drivers fix it by chance but many others don't. In true 2020 fashion the original bug fix has grown into a 5-patch scheduler/RCU fix series plus another 16 RCU patches to address the underlying issue of missed preemption events. These are the initial fixes that should fix current incarnations of the bug. - Clean up rbtree usage in the scheduler, by providing & using the following consistent set of rbtree APIs: partial-order; less() based: - rb_add(): add a new entry to the rbtree - rb_add_cached(): like rb_add(), but for a rb_root_cached total-order; cmp() based: - rb_find(): find an entry in an rbtree - rb_find_add(): find an entry, and add if not found - rb_find_first(): find the first (leftmost) matching entry - rb_next_match(): continue from rb_find_first() - rb_for_each(): iterate a sub-tree using the previous two - Improve the SMP/NUMA load-balancer: scan for an idle sibling in a single pass. This is a 4-commit series where each commit improves one aspect of the idle sibling scan logic. - Improve the cpufreq cooling driver by getting the effective CPU utilization metrics from the scheduler - Improve the fair scheduler's active load-balancing logic by reducing the number of active LB attempts & lengthen the load-balancing interval. This improves stress-ng mmapfork performance. - Fix CFS's estimated utilization (util_est) calculation bug that can result in too high utilization values Misc updates & fixes: - Fix the HRTICK reprogramming & optimization feature - Fix SCHED_SOFTIRQ raising race & warning in the CPU offlining code - Reduce dl_add_task_root_domain() overhead - Fix uprobes refcount bug - Process pending softirqs in flush_smp_call_function_from_idle() - Clean up task priority related defines, remove *USER_*PRIO and USER_PRIO() - Simplify the sched_init_numa() deduplication sort - Documentation updates - Fix EAS bug in update_misfit_status(), which degraded the quality of energy-balancing - Smaller cleanups" * tag 'sched-core-2021-02-17' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (51 commits) sched,x86: Allow !PREEMPT_DYNAMIC entry/kvm: Explicitly flush pending rcuog wakeup before last rescheduling point entry: Explicitly flush pending rcuog wakeup before last rescheduling point rcu/nocb: Trigger self-IPI on late deferred wake up before user resume rcu/nocb: Perform deferred wake up before last idle's need_resched() check rcu: Pull deferred rcuog wake up to rcu_eqs_enter() callers sched/features: Distinguish between NORMAL and DEADLINE hrtick sched/features: Fix hrtick reprogramming sched/deadline: Reduce rq lock contention in dl_add_task_root_domain() uprobes: (Re)add missing get_uprobe() in __find_uprobe() smp: Process pending softirqs in flush_smp_call_function_from_idle() sched: Harden PREEMPT_DYNAMIC static_call: Allow module use without exposing static_call_key sched: Add /debug/sched_preempt preempt/dynamic: Support dynamic preempt with preempt= boot option preempt/dynamic: Provide irqentry_exit_cond_resched() static call preempt/dynamic: Provide preempt_schedule[_notrace]() static calls preempt/dynamic: Provide cond_resched() and might_resched() static calls preempt: Introduce CONFIG_PREEMPT_DYNAMIC static_call: Provide DEFINE_STATIC_CALL_RET0() ...
2021-02-21Merge tag 'oprofile-removal-5.12' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/vireshk/linux Pull oprofile and dcookies removal from Viresh Kumar: "Remove oprofile and dcookies support The 'oprofile' user-space tools don't use the kernel OPROFILE support any more, and haven't in a long time. User-space has been converted to the perf interfaces. The dcookies stuff is only used by the oprofile code. Now that oprofile's support is getting removed from the kernel, there is no need for dcookies as well. Remove kernel's old oprofile and dcookies support" * tag 'oprofile-removal-5.12' of git://git.kernel.org/pub/scm/linux/kernel/git/vireshk/linux: fs: Remove dcookies support drivers: Remove CONFIG_OPROFILE support arch: xtensa: Remove CONFIG_OPROFILE support arch: x86: Remove CONFIG_OPROFILE support arch: sparc: Remove CONFIG_OPROFILE support arch: sh: Remove CONFIG_OPROFILE support arch: s390: Remove CONFIG_OPROFILE support arch: powerpc: Remove oprofile arch: powerpc: Stop building and using oprofile arch: parisc: Remove CONFIG_OPROFILE support arch: mips: Remove CONFIG_OPROFILE support arch: microblaze: Remove CONFIG_OPROFILE support arch: ia64: Remove rest of perfmon support arch: ia64: Remove CONFIG_OPROFILE support arch: hexagon: Don't select HAVE_OPROFILE arch: arc: Remove CONFIG_OPROFILE support arch: arm: Remove CONFIG_OPROFILE support arch: alpha: Remove CONFIG_OPROFILE support
2021-02-21Merge branch 'work.elf-compat' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull ELF compat updates from Al Viro: "Sanitizing ELF compat support, especially for triarch architectures: - X32 handling cleaned up - MIPS64 uses compat_binfmt_elf.c both for O32 and N32 now - Kconfig side of things regularized Eventually I hope to have compat_binfmt_elf.c killed, with both native and compat built from fs/binfmt_elf.c, with -DELF_BITS={64,32} passed by kbuild, but that's a separate story - not included here" * 'work.elf-compat' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: get rid of COMPAT_ELF_EXEC_PAGESIZE compat_binfmt_elf: don't bother with undef of ELF_ARCH Kconfig: regularize selection of CONFIG_BINFMT_ELF mips compat: switch to compat_binfmt_elf.c mips: don't bother with ELF_CORE_EFLAGS mips compat: don't bother with ELF_ET_DYN_BASE mips: KVM_GUEST makes no sense for 64bit builds... mips: kill unused definitions in binfmt_elf[on]32.c mips binfmt_elf*32.c: use elfcore-compat.h x32: make X32, !IA32_EMULATION setups able to execute x32 binaries [amd64] clean PRSTATUS_SIZE/SET_PR_FPVALID up properly elf_prstatus: collect the common part (everything before pr_reg) into a struct binfmt_elf: partially sanitize PRSTATUS_SIZE and SET_PR_FPVALID
2021-02-17preempt: Introduce CONFIG_PREEMPT_DYNAMICMichal Hocko
Preemption mode selection is currently hardcoded on Kconfig choices. Introduce a dedicated option to tune preemption flavour at boot time, This will be only available on architectures efficiently supporting static calls in order not to tempt with the feature against additional overhead that might be prohibitive or undesirable. CONFIG_PREEMPT_DYNAMIC is automatically selected by CONFIG_PREEMPT if the architecture provides the necessary support (CONFIG_STATIC_CALL_INLINE, CONFIG_GENERIC_ENTRY, and provide with __preempt_schedule_function() / __preempt_schedule_notrace_function()). Suggested-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Michal Hocko <mhocko@suse.com> Signed-off-by: Frederic Weisbecker <frederic@kernel.org> [peterz: relax requirement to HAVE_STATIC_CALL] Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lkml.kernel.org/r/20210118141223.123667-5-frederic@kernel.org
2021-02-13s390,alpha: switch to 64-bit ino_tHeiko Carstens
s390 and alpha are the only 64 bit architectures with a 32-bit ino_t. Since this is quite unusual this causes bugs from time to time. See e.g. commit ebce3eb2f7ef ("ceph: fix inode number handling on arches with 32-bit ino_t") for an example. This (obviously) also prevents s390 and alpha to use 64-bit ino_t for tmpfs. See commit b85a7a8bb573 ("tmpfs: disallow CONFIG_TMPFS_INODE64 on s390"). Therefore switch both s390 and alpha to 64-bit ino_t. This should only have an effect on the ustat system call. To prevent ABI breakage define struct ustat compatible to the old layout and change sys_ustat() accordingly. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2021-02-10softirq: Move __ARCH_HAS_DO_SOFTIRQ to KconfigThomas Gleixner
To prepare for inlining do_softirq_own_stack() replace __ARCH_HAS_DO_SOFTIRQ with a Kconfig switch and select it in the affected architectures. This allows in the next step to move the function prototype and the inline stub into a seperate asm-generic header file which is required to avoid include recursion. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20210210002513.181713427@linutronix.de
2021-01-29drivers: Remove CONFIG_OPROFILE supportViresh Kumar
The "oprofile" user-space tools don't use the kernel OPROFILE support any more, and haven't in a long time. User-space has been converted to the perf interfaces. Remove kernel's old oprofile support. Suggested-by: Christoph Hellwig <hch@infradead.org> Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Acked-by: Robert Richter <rric@kernel.org> Acked-by: Paul E. McKenney <paulmck@kernel.org> #RCU Acked-by: William Cohen <wcohen@redhat.com> Acked-by: Al Viro <viro@zeniv.linux.org.uk> Acked-by: Thomas Gleixner <tglx@linutronix.de>
2021-01-21arch/Kconfig: update a broken file referenceLukas Bulwahn
Commit adab66b71abf ("Revert: "ring-buffer: Remove HAVE_64BIT_ALIGNED_ACCESS"") added the config HAVE_64BIT_ALIGNED_ACCESS back into arch/Kconfig with this revert. In the meantime, commit c9b54d6f362c ("docs: move other kAPI documents to core-api") changed ./Documentation/unaligned-memory-access.txt to ./Documentation/core-api/unaligned-memory-access.rst. Fortunately, ./scripts/documentation-file-ref-check detects this and warns about this broken reference. Update the file reference in arch/Kconfig. Fixes: adab66b71abf ("Revert: "ring-buffer: Remove HAVE_64BIT_ALIGNED_ACCESS"") Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com> Link: https://lore.kernel.org/r/20210119095326.13896-1-lukas.bulwahn@gmail.com Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2021-01-14kbuild: lto: fix module versioningSami Tolvanen
With CONFIG_MODVERSIONS, version information is linked into each compilation unit that exports symbols. With LTO, we cannot use this method as all C code is compiled into LLVM bitcode instead. This change collects symbol versions into .symversions files and merges them in link-vmlinux.sh where they are all linked into vmlinux.o at the same time. Signed-off-by: Sami Tolvanen <samitolvanen@google.com> Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20201211184633.3213045-4-samitolvanen@google.com
2021-01-14kbuild: add support for Clang LTOSami Tolvanen
This change adds build system support for Clang's Link Time Optimization (LTO). With -flto, instead of ELF object files, Clang produces LLVM bitcode, which is compiled into native code at link time, allowing the final binary to be optimized globally. For more details, see: https://llvm.org/docs/LinkTimeOptimization.html The Kconfig option CONFIG_LTO_CLANG is implemented as a choice, which defaults to LTO being disabled. To use LTO, the architecture must select ARCH_SUPPORTS_LTO_CLANG and support: - compiling with Clang, - compiling all assembly code with Clang's integrated assembler, - and linking with LLD. While using CONFIG_LTO_CLANG_FULL results in the best runtime performance, the compilation is not scalable in time or memory. CONFIG_LTO_CLANG_THIN enables ThinLTO, which allows parallel optimization and faster incremental builds. ThinLTO is used by default if the architecture also selects ARCH_SUPPORTS_LTO_CLANG_THIN: https://clang.llvm.org/docs/ThinLTO.html To enable LTO, LLVM tools must be used to handle bitcode files, by passing LLVM=1 and LLVM_IAS=1 options to make: $ make LLVM=1 LLVM_IAS=1 defconfig $ scripts/config -e LTO_CLANG_THIN $ make LLVM=1 LLVM_IAS=1 To prepare for LTO support with other compilers, common parts are gated behind the CONFIG_LTO option, and LTO can be disabled for specific files by filtering out CC_FLAGS_LTO. Signed-off-by: Sami Tolvanen <samitolvanen@google.com> Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20201211184633.3213045-3-samitolvanen@google.com
2021-01-06[amd64] clean PRSTATUS_SIZE/SET_PR_FPVALID up properlyAl Viro
To get rid of hardcoded size/offset in those macros we need to have a definition of i386 variant of struct elf_prstatus. However, we can't do that in asm/compat.h - the types needed for that are not there and adding an include of asm/user32.h into asm/compat.h would cause a lot of mess. That could be conveniently done in elfcore-compat.h, but currently there is nowhere to put arch-dependent parts of it - no asm/elfcore-compat.h. So we introduce a new file (asm/elfcore-compat.h, present on architectures that have CONFIG_ARCH_HAS_ELFCORE_COMPAT set, currently only on x86), have it pulled by linux/elfcore-compat.h and move the definitions there. As a side benefit, we don't need to worry about accidental inclusion of that file into binfmt_elf.c itself, so we don't need the dance with COMPAT_PRSTATUS_SIZE, etc. - only fs/compat_binfmt_elf.c will see that header. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-12-28fanotify: Fix sys_fanotify_mark() on native x86-32Brian Gerst
Commit 121b32a58a3a ("x86/entry/32: Use IA32-specific wrappers for syscalls taking 64-bit arguments") converted native x86-32 which take 64-bit arguments to use the compat handlers to allow conversion to passing args via pt_regs. sys_fanotify_mark() was however missed, as it has a general compat handler. Add a config option that will use the syscall wrapper that takes the split args for native 32-bit. [ bp: Fix typo in Kconfig help text. ] Fixes: 121b32a58a3a ("x86/entry/32: Use IA32-specific wrappers for syscalls taking 64-bit arguments") Reported-by: Paweł Jasiak <pawel@jasiak.xyz> Signed-off-by: Brian Gerst <brgerst@gmail.com> Signed-off-by: Borislav Petkov <bp@suse.de> Acked-by: Jan Kara <jack@suse.cz> Acked-by: Andy Lutomirski <luto@kernel.org> Link: https://lkml.kernel.org/r/20201130223059.101286-1-brgerst@gmail.com
2020-12-22kasan: allow VMAP_STACK for HW_TAGS modeAndrey Konovalov
Even though hardware tag-based mode currently doesn't support checking vmalloc allocations, it doesn't use shadow memory and works with VMAP_STACK as is. Change VMAP_STACK definition accordingly. Link: https://lkml.kernel.org/r/ecdb2a1658ebd88eb276dee2493518ac0e82de41.1606162397.git.andreyknvl@google.com Link: https://linux-review.googlesource.com/id/I3552cbc12321dec82cd7372676e9372a2eb452ac Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Reviewed-by: Marco Elver <elver@google.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Reviewed-by: Dmitry Vyukov <dvyukov@google.com> Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Branislav Rankov <Branislav.Rankov@arm.com> Cc: Evgenii Stepanov <eugenis@google.com> Cc: Kevin Brodsky <kevin.brodsky@arm.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-12-17Merge tag 'trace-v5.11' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull tracing updates from Steven Rostedt: "The major update to this release is that there's a new arch config option called CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS. Currently, only x86_64 enables it. All the ftrace callbacks now take a struct ftrace_regs instead of a struct pt_regs. If the architecture has HAVE_DYNAMIC_FTRACE_WITH_ARGS enabled, then the ftrace_regs will have enough information to read the arguments of the function being traced, as well as access to the stack pointer. This way, if a user (like live kernel patching) only cares about the arguments, then it can avoid using the heavier weight "regs" callback, that puts in enough information in the struct ftrace_regs to simulate a breakpoint exception (needed for kprobes). A new config option that audits the timestamps of the ftrace ring buffer at most every event recorded. Ftrace recursion protection has been cleaned up to move the protection to the callback itself (this saves on an extra function call for those callbacks). Perf now handles its own RCU protection and does not depend on ftrace to do it for it (saving on that extra function call). New debug option to add "recursed_functions" file to tracefs that lists all the places that triggered the recursion protection of the function tracer. This will show where things need to be fixed as recursion slows down the function tracer. The eval enum mapping updates done at boot up are now offloaded to a work queue, as it caused a noticeable pause on slow embedded boards. Various clean ups and last minute fixes" * tag 'trace-v5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (33 commits) tracing: Offload eval map updates to a work queue Revert: "ring-buffer: Remove HAVE_64BIT_ALIGNED_ACCESS" ring-buffer: Add rb_check_bpage in __rb_allocate_pages ring-buffer: Fix two typos in comments tracing: Drop unneeded assignment in ring_buffer_resize() tracing: Disable ftrace selftests when any tracer is running seq_buf: Avoid type mismatch for seq_buf_init ring-buffer: Fix a typo in function description ring-buffer: Remove obsolete rb_event_is_commit() ring-buffer: Add test to validate the time stamp deltas ftrace/documentation: Fix RST C code blocks tracing: Clean up after filter logic rewriting tracing: Remove the useless value assignment in test_create_synth_event() livepatch: Use the default ftrace_ops instead of REGS when ARGS is available ftrace/x86: Allow for arguments to be passed in to ftrace_regs by default ftrace: Have the callbacks receive a struct ftrace_regs instead of pt_regs MAINTAINERS: assign ./fs/tracefs to TRACING tracing: Fix some typos in comments ftrace: Remove unused varible 'ret' ring-buffer: Add recording of ring buffer recursion into recursed_functions ...
2020-12-16Merge tag 'seccomp-v5.11-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux Pull seccomp updates from Kees Cook: "The major change here is finally gaining seccomp constant-action bitmaps, which internally reduces the seccomp overhead for many real-world syscall filters to O(1), as discussed at Plumbers this year. - Improve seccomp performance via constant-action bitmaps (YiFei Zhu & Kees Cook) - Fix bogus __user annotations (Jann Horn) - Add missed CONFIG for improved selftest coverage (Mickaël Salaün)" * tag 'seccomp-v5.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: selftests/seccomp: Update kernel config seccomp: Remove bogus __user annotations seccomp/cache: Report cache data through /proc/pid/seccomp_cache xtensa: Enable seccomp architecture tracking sh: Enable seccomp architecture tracking s390: Enable seccomp architecture tracking riscv: Enable seccomp architecture tracking powerpc: Enable seccomp architecture tracking parisc: Enable seccomp architecture tracking csky: Enable seccomp architecture tracking arm: Enable seccomp architecture tracking arm64: Enable seccomp architecture tracking selftests/seccomp: Compare bitmap vs filter overhead x86: Enable seccomp architecture tracking seccomp/cache: Add "emulator" to check if filter is constant allow seccomp/cache: Lookup syscall allowlist bitmap for fast path
2020-12-15Merge tag 'irq-core-2020-12-15' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull irq updates from Thomas Gleixner: "Generic interrupt and irqchips subsystem updates. Unusually, there is not a single completely new irq chip driver, just new DT bindings and extensions of existing drivers to accomodate new variants! Core: - Consolidation and robustness changes for irq time accounting - Cleanup and consolidation of irq stats - Remove the fasteoi IPI flow which has been proved useless - Provide an interface for converting legacy interrupt mechanism into irqdomains Drivers: - Preliminary support for managed interrupts on platform devices - Correctly identify allocation of MSIs proxyied by another device - Generalise the Ocelot support to new SoCs - Improve GICv4.1 vcpu entry, matching the corresponding KVM optimisation - Work around spurious interrupts on Qualcomm PDC - Random fixes and cleanups" * tag 'irq-core-2020-12-15' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (54 commits) irqchip/qcom-pdc: Fix phantom irq when changing between rising/falling driver core: platform: Add devm_platform_get_irqs_affinity() ACPI: Drop acpi_dev_irqresource_disabled() resource: Add irqresource_disabled() genirq/affinity: Add irq_update_affinity_desc() irqchip/gic-v3-its: Flag device allocation as proxied if behind a PCI bridge irqchip/gic-v3-its: Tag ITS device as shared if allocating for a proxy device platform-msi: Track shared domain allocation irqchip/ti-sci-intr: Fix freeing of irqs irqchip/ti-sci-inta: Fix printing of inta id on probe success drivers/irqchip: Remove EZChip NPS interrupt controller Revert "genirq: Add fasteoi IPI flow" irqchip/hip04: Make IPIs use handle_percpu_devid_irq() irqchip/bcm2836: Make IPIs use handle_percpu_devid_irq() irqchip/armada-370-xp: Make IPIs use handle_percpu_devid_irq() irqchip/gic, gic-v3: Make SGIs use handle_percpu_devid_irq() irqchip/ocelot: Add support for Jaguar2 platforms irqchip/ocelot: Add support for Serval platforms irqchip/ocelot: Add support for Luton platforms irqchip/ocelot: prepare to support more SoC ...
2020-12-15Merge branch 'akpm' (patches from Andrew)Linus Torvalds
Merge misc updates from Andrew Morton: - a few random little subsystems - almost all of the MM patches which are staged ahead of linux-next material. I'll trickle to post-linux-next work in as the dependents get merged up. Subsystems affected by this patch series: kthread, kbuild, ide, ntfs, ocfs2, arch, and mm (slab-generic, slab, slub, dax, debug, pagecache, gup, swap, shmem, memcg, pagemap, mremap, hmm, vmalloc, documentation, kasan, pagealloc, memory-failure, hugetlb, vmscan, z3fold, compaction, oom-kill, migration, cma, page-poison, userfaultfd, zswap, zsmalloc, uaccess, zram, and cleanups). * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (200 commits) mm: cleanup kstrto*() usage mm: fix fall-through warnings for Clang mm: slub: convert sysfs sprintf family to sysfs_emit/sysfs_emit_at mm: shmem: convert shmem_enabled_show to use sysfs_emit_at mm:backing-dev: use sysfs_emit in macro defining functions mm: huge_memory: convert remaining use of sprintf to sysfs_emit and neatening mm: use sysfs_emit for struct kobject * uses mm: fix kernel-doc markups zram: break the strict dependency from lzo zram: add stat to gather incompressible pages since zram set up zram: support page writeback mm/process_vm_access: remove redundant initialization of iov_r mm/zsmalloc.c: rework the list_add code in insert_zspage() mm/zswap: move to use crypto_acomp API for hardware acceleration mm/zswap: fix passing zero to 'PTR_ERR' warning mm/zswap: make struct kernel_param_ops definitions const userfaultfd/selftests: hint the test runner on required privilege userfaultfd/selftests: fix retval check for userfaultfd_open() userfaultfd/selftests: always dump something in modes userfaultfd: selftests: make __{s,u}64 format specifiers portable ...
2020-12-15arch, mm: restore dependency of __kernel_map_pages() on DEBUG_PAGEALLOCMike Rapoport
The design of DEBUG_PAGEALLOC presumes that __kernel_map_pages() must never fail. With this assumption is wouldn't be safe to allow general usage of this function. Moreover, some architectures that implement __kernel_map_pages() have this function guarded by #ifdef DEBUG_PAGEALLOC and some refuse to map/unmap pages when page allocation debugging is disabled at runtime. As all the users of __kernel_map_pages() were converted to use debug_pagealloc_map_pages() it is safe to make it available only when DEBUG_PAGEALLOC is set. Link: https://lkml.kernel.org/r/20201109192128.960-4-rppt@kernel.org Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> Acked-by: David Hildenbrand <david@redhat.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Andy Lutomirski <luto@kernel.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Christoph Lameter <cl@linux.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Rientjes <rientjes@google.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: "Edgecombe, Rick P" <rick.p.edgecombe@intel.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Len Brown <len.brown@intel.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Pavel Machek <pavel@ucw.cz> Cc: Pekka Enberg <penberg@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-12-15arm, arm64: move free_unused_memmap() to generic mmMike Rapoport
ARM and ARM64 free unused parts of the memory map just before the initialization of the page allocator. To allow holes in the memory map both architectures overload pfn_valid() and define HAVE_ARCH_PFN_VALID. Allowing holes in the memory map for FLATMEM may be useful for small machines, such as ARC and m68k and will enable those architectures to cease using DISCONTIGMEM and still support more than one memory bank. Move the functions that free unused memory map to generic mm and enable them in case HAVE_ARCH_PFN_VALID=y. Link: https://lkml.kernel.org/r/20201101170454.9567-10-rppt@kernel.org Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> [arm64] Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Greg Ungerer <gerg@linux-m68k.org> Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Matt Turner <mattst88@gmail.com> Cc: Meelis Roos <mroos@linux.ee> Cc: Michael Schmitz <schmitzmic@gmail.com> Cc: Russell King <linux@armlinux.org.uk> Cc: Tony Luck <tony.luck@intel.com> Cc: Vineet Gupta <vgupta@synopsys.com> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-12-15mm: speedup mremap on 1GB or larger regionsKalesh Singh
Android needs to move large memory regions for garbage collection. The GC requires moving physical pages of multi-gigabyte heap using mremap. During this move, the application threads have to be paused for correctness. It is critical to keep this pause as short as possible to avoid jitters during user interaction. Optimize mremap for >= 1GB-sized regions by moving at the PUD/PGD level if the source and destination addresses are PUD-aligned. For CONFIG_PGTABLE_LEVELS == 3, moving at the PUD level in effect moves PGD entries, since the PUD entry is “folded back” onto the PGD entry. Add HAVE_MOVE_PUD so that architectures where moving at the PUD level isn't supported/tested can turn this off by not selecting the config. Link: https://lkml.kernel.org/r/20201014005320.2233162-4-kaleshsingh@google.com Signed-off-by: Kalesh Singh <kaleshsingh@google.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Reported-by: kernel test robot <lkp@intel.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Geffon <bgeffon@google.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christian Brauner <christian.brauner@ubuntu.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Frederic Weisbecker <frederic@kernel.org> Cc: Gavin Shan <gshan@redhat.com> Cc: Hassan Naveed <hnaveed@wavecomp.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jia He <justin.he@arm.com> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Kees Cook <keescook@chromium.org> Cc: Krzysztof Kozlowski <krzk@kernel.org> Cc: Lokesh Gidra <lokeshgidra@google.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Masahiro Yamada <masahiroy@kernel.org> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mike Rapoport <rppt@kernel.org> Cc: Mina Almasry <almasrymina@google.com> Cc: Minchan Kim <minchan@google.com> Cc: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Ralph Campbell <rcampbell@nvidia.com> Cc: Ram Pai <linuxram@us.ibm.com> Cc: Sami Tolvanen <samitolvanen@google.com> Cc: Sandipan Das <sandipan@linux.ibm.com> Cc: SeongJae Park <sjpark@amazon.de> Cc: Shuah Khan <shuah@kernel.org> Cc: Steven Price <steven.price@arm.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Deacon <will@kernel.org> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-12-15arch/Kconfig: fix spelling mistakesColin Ian King
There are a few spelling mistakes in the Kconfig comments and help text. Fix these. Link: https://lkml.kernel.org/r/20201207155004.171962-1-colin.king@canonical.com Signed-off-by: Colin Ian King <colin.king@canonical.com> Acked-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-12-14Merge tag 'core-entry-2020-12-14' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull core entry/exit updates from Thomas Gleixner: "A set of updates for entry/exit handling: - More generalization of entry/exit functionality - The consolidation work to reclaim TIF flags on x86 and also for non-x86 specific TIF flags which are solely relevant for syscall related work and have been moved into their own storage space. The x86 specific part had to be merged in to avoid a major conflict. - The TIF_NOTIFY_SIGNAL work which replaces the inefficient signal delivery mode of task work and results in an impressive performance improvement for io_uring. The non-x86 consolidation of this is going to come seperate via Jens. - The selective syscall redirection facility which provides a clean and efficient way to support the non-Linux syscalls of WINE by catching them at syscall entry and redirecting them to the user space emulation. This can be utilized for other purposes as well and has been designed carefully to avoid overhead for the regular fastpath. This includes the core changes and the x86 support code. - Simplification of the context tracking entry/exit handling for the users of the generic entry code which guarantee the proper ordering and protection. - Preparatory changes to make the generic entry code accomodate S390 specific requirements which are mostly related to their syscall restart mechanism" * tag 'core-entry-2020-12-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (36 commits) entry: Add syscall_exit_to_user_mode_work() entry: Add exit_to_user_mode() wrapper entry_Add_enter_from_user_mode_wrapper entry: Rename exit_to_user_mode() entry: Rename enter_from_user_mode() docs: Document Syscall User Dispatch selftests: Add benchmark for syscall user dispatch selftests: Add kselftest for syscall user dispatch entry: Support Syscall User Dispatch on common syscall entry kernel: Implement selective syscall userspace redirection signal: Expose SYS_USER_DISPATCH si_code type x86: vdso: Expose sigreturn address on vdso to the kernel MAINTAINERS: Add entry for common entry code entry: Fix boot for !CONFIG_GENERIC_ENTRY x86: Support HAVE_CONTEXT_TRACKING_OFFSTACK context_tracking: Only define schedule_user() on !HAVE_CONTEXT_TRACKING_OFFSTACK archs sched: Detect call to schedule from critical entry code context_tracking: Don't implement exception_enter/exit() on CONFIG_HAVE_CONTEXT_TRACKING_OFFSTACK context_tracking: Introduce HAVE_CONTEXT_TRACKING_OFFSTACK x86: Reclaim unused x86 TI flags ...
2020-12-14Revert: "ring-buffer: Remove HAVE_64BIT_ALIGNED_ACCESS"Steven Rostedt (VMware)
It was believed that metag was the only architecture that required the ring buffer to keep 8 byte words aligned on 8 byte architectures, and with its removal, it was assumed that the ring buffer code did not need to handle this case. It appears that sparc64 also requires this. The following was reported on a sparc64 boot up: kernel: futex hash table entries: 65536 (order: 9, 4194304 bytes, linear) kernel: Running postponed tracer tests: kernel: Testing tracer function: kernel: Kernel unaligned access at TPC[552a20] trace_function+0x40/0x140 kernel: Kernel unaligned access at TPC[552a24] trace_function+0x44/0x140 kernel: Kernel unaligned access at TPC[552a20] trace_function+0x40/0x140 kernel: Kernel unaligned access at TPC[552a24] trace_function+0x44/0x140 kernel: Kernel unaligned access at TPC[552a20] trace_function+0x40/0x140 kernel: PASSED Need to put back the 64BIT aligned code for the ring buffer. Link: https://lore.kernel.org/r/CADxRZqzXQRYgKc=y-KV=S_yHL+Y8Ay2mh5ezeZUnpRvg+syWKw@mail.gmail.com Cc: stable@vger.kernel.org Fixes: 86b3de60a0b6 ("ring-buffer: Remove HAVE_64BIT_ALIGNED_ACCESS") Reported-by: Anatoly Pugachev <matorola@gmail.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-12-02s390/vtime: Use the generic IRQ entry accountingFrederic Weisbecker
s390 has its own version of IRQ entry accounting because it doesn't account the idle time the same way the other architectures do. Only the actual idle sleep time is accounted as idle time, the rest of the idle task execution is accounted as system time. Make the generic IRQ entry accounting aware of architectures that have their own way of accounting idle time and convert s390 to use it. This prepares s390 to get involved in further consolidations of IRQ time accounting. Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20201202115732.27827-3-frederic@kernel.org
2020-12-01kbuild: Hoist '--orphan-handling' into KconfigNathan Chancellor
Currently, '--orphan-handling=warn' is spread out across four different architectures in their respective Makefiles, which makes it a little unruly to deal with in case it needs to be disabled for a specific linker version (in this case, ld.lld 10.0.1). To make it easier to control this, hoist this warning into Kconfig and the main Makefile so that disabling it is simpler, as the warning will only be enabled in a couple places (main Makefile and a couple of compressed boot folders that blow away LDFLAGS_vmlinx) and making it conditional is easier due to Kconfig syntax. One small additional benefit of this is saving a call to ld-option on incremental builds because we will have already evaluated it for CONFIG_LD_ORPHAN_WARN. To keep the list of supported architectures the same, introduce CONFIG_ARCH_WANT_LD_ORPHAN_WARN, which an architecture can select to gain this automatically after all of the sections are specified and size asserted. A special thanks to Kees Cook for the help text on this config. Link: https://github.com/ClangBuiltLinux/linux/issues/1187 Acked-by: Kees Cook <keescook@chromium.org> Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc) Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Tested-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Nathan Chancellor <natechancellor@gmail.com> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-11-20seccomp/cache: Report cache data through /proc/pid/seccomp_cacheYiFei Zhu
Currently the kernel does not provide an infrastructure to translate architecture numbers to a human-readable name. Translating syscall numbers to syscall names is possible through FTRACE_SYSCALL infrastructure but it does not provide support for compat syscalls. This will create a file for each PID as /proc/pid/seccomp_cache. The file will be empty when no seccomp filters are loaded, or be in the format of: <arch name> <decimal syscall number> <ALLOW | FILTER> where ALLOW means the cache is guaranteed to allow the syscall, and filter means the cache will pass the syscall to the BPF filter. For the docker default profile on x86_64 it looks like: x86_64 0 ALLOW x86_64 1 ALLOW x86_64 2 ALLOW x86_64 3 ALLOW [...] x86_64 132 ALLOW x86_64 133 ALLOW x86_64 134 FILTER x86_64 135 FILTER x86_64 136 FILTER x86_64 137 ALLOW x86_64 138 ALLOW x86_64 139 FILTER x86_64 140 ALLOW x86_64 141 ALLOW [...] This file is guarded by CONFIG_SECCOMP_CACHE_DEBUG with a default of N because I think certain users of seccomp might not want the application to know which syscalls are definitely usable. For the same reason, it is also guarded by CAP_SYS_ADMIN. Suggested-by: Jann Horn <jannh@google.com> Link: https://lore.kernel.org/lkml/CAG48ez3Ofqp4crXGksLmZY6=fGrF_tWyUCg7PBkAetvbbOPeOA@mail.gmail.com/ Signed-off-by: YiFei Zhu <yifeifz2@illinois.edu> Signed-off-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/94e663fa53136f5a11f432c661794d1ee7060779.1605101222.git.yifeifz2@illinois.edu
2020-11-19context_tracking: Introduce HAVE_CONTEXT_TRACKING_OFFSTACKFrederic Weisbecker
Historically, context tracking had to deal with fragile entry code path, ie: before user_exit() is called and after user_enter() is called, in case some of those spots would call schedule() or use RCU. On such cases, the site had to be protected between exception_enter() and exception_exit() that save the context tracking state in the task stack. Such sleepable fragile code path had many different origins: tracing, exceptions, early or late calls to context tracking on syscalls... Aside of that not being pretty, saving the context tracking state on the task stack forces us to run context tracking on all CPUs, including housekeepers, and prevents us to completely shutdown nohz_full at runtime on a CPU in the future as context tracking and its overhead would still need to run system wide. Now thanks to the extensive efforts to sanitize x86 entry code, those conditions have been removed and we can now get rid of these workarounds in this architecture. Create a Kconfig feature to express this achievement. Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20201117151637.259084-2-frederic@kernel.org
2020-10-22Merge branch 'work.set_fs' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull initial set_fs() removal from Al Viro: "Christoph's set_fs base series + fixups" * 'work.set_fs' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: fs: Allow a NULL pos pointer to __kernel_read fs: Allow a NULL pos pointer to __kernel_write powerpc: remove address space overrides using set_fs() powerpc: use non-set_fs based maccess routines x86: remove address space overrides using set_fs() x86: make TASK_SIZE_MAX usable from assembly code x86: move PAGE_OFFSET, TASK_SIZE & friends to page_{32,64}_types.h lkdtm: remove set_fs-based tests test_bitmap: remove user bitmap tests uaccess: add infrastructure for kernel builds with set_fs() fs: don't allow splice read/write without explicit ops fs: don't allow kernel reads and writes without iter ops sysctl: Convert to iter interfaces proc: add a read_iter method to proc proc_ops proc: cleanup the compat vs no compat file ops proc: remove a level of indentation in proc_get_inode
2020-10-16Merge tag 'powerpc-5.10-1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux 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 ...
2020-10-13Merge tag 'seccomp-v5.10-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux Pull seccomp updates from Kees Cook: "The bulk of the changes are with the seccomp selftests to accommodate some powerpc-specific behavioral characteristics. Additional cleanups, fixes, and improvements are also included: - heavily refactor seccomp selftests (and clone3 selftests dependency) to fix powerpc (Kees Cook, Thadeu Lima de Souza Cascardo) - fix style issue in selftests (Zou Wei) - upgrade "unknown action" from KILL_THREAD to KILL_PROCESS (Rich Felker) - replace task_pt_regs(current) with current_pt_regs() (Denis Efremov) - fix corner-case race in USER_NOTIF (Jann Horn) - make CONFIG_SECCOMP no longer per-arch (YiFei Zhu)" * tag 'seccomp-v5.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: (23 commits) seccomp: Make duplicate listener detection non-racy seccomp: Move config option SECCOMP to arch/Kconfig selftests/clone3: Avoid OS-defined clone_args selftests/seccomp: powerpc: Set syscall return during ptrace syscall exit selftests/seccomp: Allow syscall nr and ret value to be set separately selftests/seccomp: Record syscall during ptrace entry selftests/seccomp: powerpc: Fix seccomp return value testing selftests/seccomp: Remove SYSCALL_NUM_RET_SHARE_REG in favor of SYSCALL_RET_SET selftests/seccomp: Avoid redundant register flushes selftests/seccomp: Convert REGSET calls into ARCH_GETREG/ARCH_SETREG selftests/seccomp: Convert HAVE_GETREG into ARCH_GETREG/ARCH_SETREG selftests/seccomp: Remove syscall setting #ifdefs selftests/seccomp: mips: Remove O32-specific macro selftests/seccomp: arm64: Define SYSCALL_NUM_SET macro selftests/seccomp: arm: Define SYSCALL_NUM_SET macro selftests/seccomp: mips: Define SYSCALL_NUM_SET macro selftests/seccomp: Provide generic syscall setting macro selftests/seccomp: Refactor arch register macros to avoid xtensa special case selftests/seccomp: Use __NR_mknodat instead of __NR_mknod selftests/seccomp: Use bitwise instead of arithmetic operator for flags ...
2020-10-08seccomp: Move config option SECCOMP to arch/KconfigYiFei Zhu
In order to make adding configurable features into seccomp easier, it's better to have the options at one single location, considering especially that the bulk of seccomp code is arch-independent. An quick look also show that many SECCOMP descriptions are outdated; they talk about /proc rather than prctl. As a result of moving the config option and keeping it default on, architectures arm, arm64, csky, riscv, sh, and xtensa did not have SECCOMP on by default prior to this and SECCOMP will be default in this change. Architectures microblaze, mips, powerpc, s390, sh, and sparc have an outdated depend on PROC_FS and this dependency is removed in this change. Suggested-by: Jann Horn <jannh@google.com> Link: https://lore.kernel.org/lkml/CAG48ez1YWz9cnp08UZgeieYRhHdqh-ch7aNwc4JRBnGyrmgfMg@mail.gmail.com/ Signed-off-by: YiFei Zhu <yifeifz2@illinois.edu> [kees: added HAVE_ARCH_SECCOMP help text, tweaked wording] Signed-off-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/9ede6ef35c847e58d61e476c6a39540520066613.1600951211.git.yifeifz2@illinois.edu
2020-09-16mm: fix exec activate_mm vs TLB shootdown and lazy tlb switching raceNicholas Piggin
Reading and modifying current->mm and current->active_mm and switching mm should be done with irqs off, to prevent races seeing an intermediate state. This is similar to commit 38cf307c1f20 ("mm: fix kthread_use_mm() vs TLB invalidate"). At exec-time when the new mm is activated, the old one should usually be single-threaded and no longer used, unless something else is holding an mm_users reference (which may be possible). Absent other mm_users, there is also a race with preemption and lazy tlb switching. Consider the kernel_execve case where the current thread is using a lazy tlb active mm: call_usermodehelper() kernel_execve() old_mm = current->mm; active_mm = current->active_mm; *** preempt *** --------------------> schedule() prev->active_mm = NULL; mmdrop(prev active_mm); ... <-------------------- schedule() current->mm = mm; current->active_mm = mm; if (!old_mm) mmdrop(active_mm); If we switch back to the kernel thread from a different mm, there is a double free of the old active_mm, and a missing free of the new one. Closing this race only requires interrupts to be disabled while ->mm and ->active_mm are being switched, but the TLB problem requires also holding interrupts off over activate_mm. Unfortunately not all archs can do that yet, e.g., arm defers the switch if irqs are disabled and expects finish_arch_post_lock_switch() to be called to complete the flush; um takes a blocking lock in activate_mm(). So as a first step, disable interrupts across the mm/active_mm updates to close the lazy tlb preempt race, and provide an arch option to extend that to activate_mm which allows architectures doing IPI based TLB shootdowns to close the second race. This is a bit ugly, but in the interest of fixing the bug and backporting before all architectures are converted this is a compromise. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200914045219.3736466-2-npiggin@gmail.com
2020-09-08uaccess: add infrastructure for kernel builds with set_fs()Christoph Hellwig
Add a CONFIG_SET_FS option that is selected by architecturess that implement set_fs, which is all of them initially. If the option is not set stubs for routines related to overriding the address space are provided so that architectures can start to opt out of providing set_fs. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-09-01static_call: Add simple self-test for static callsPeter Zijlstra
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20200818135804.922581202@infradead.org
2020-09-01static_call: Add inline static call infrastructureJosh Poimboeuf
Add infrastructure for an arch-specific CONFIG_HAVE_STATIC_CALL_INLINE option, which is a faster version of CONFIG_HAVE_STATIC_CALL. At runtime, the static call sites are patched directly, rather than using the out-of-line trampolines. Compared to out-of-line static calls, the performance benefits are more modest, but still measurable. Steven Rostedt did some tracepoint measurements: https://lkml.kernel.org/r/20181126155405.72b4f718@gandalf.local.home This code is heavily inspired by the jump label code (aka "static jumps"), as some of the concepts are very similar. For more details, see the comments in include/linux/static_call.h. [peterz: simplified interface; merged trampolines] Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: https://lore.kernel.org/r/20200818135804.684334440@infradead.org
2020-09-01static_call: Add basic static call infrastructureJosh Poimboeuf
Static calls are a replacement for global function pointers. They use code patching to allow direct calls to be used instead of indirect calls. They give the flexibility of function pointers, but with improved performance. This is especially important for cases where retpolines would otherwise be used, as retpolines can significantly impact performance. The concept and code are an extension of previous work done by Ard Biesheuvel and Steven Rostedt: https://lkml.kernel.org/r/20181005081333.15018-1-ard.biesheuvel@linaro.org https://lkml.kernel.org/r/20181006015110.653946300@goodmis.org There are two implementations, depending on arch support: 1) out-of-line: patched trampolines (CONFIG_HAVE_STATIC_CALL) 2) basic function pointers For more details, see the comments in include/linux/static_call.h. [peterz: simplified interface] Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: https://lore.kernel.org/r/20200818135804.623259796@infradead.org
2020-08-14Merge tag 'timers-urgent-2020-08-14' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull timekeeping updates from Thomas Gleixner: "A set of timekeeping/VDSO updates: - Preparatory work to allow S390 to switch over to the generic VDSO implementation. S390 requires that the VDSO data pointer is handed in to the counter read function when time namespace support is enabled. Adding the pointer is a NOOP for all other architectures because the compiler is supposed to optimize that out when it is unused in the architecture specific inline. The change also solved a similar problem for MIPS which fortunately has time namespaces not yet enabled. S390 needs to update clock related VDSO data independent of the timekeeping updates. This was solved so far with yet another sequence counter in the S390 implementation. A better solution is to utilize the already existing VDSO sequence count for this. The core code now exposes helper functions which allow to serialize against the timekeeper code and against concurrent readers. S390 needs extra data for their clock readout function. The initial common VDSO data structure did not provide a way to add that. It now has an embedded architecture specific struct embedded which defaults to an empty struct. Doing this now avoids tree dependencies and conflicts post rc1 and allows all other architectures which work on generic VDSO support to work from a common upstream base. - A trivial comment fix" * tag 'timers-urgent-2020-08-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: time: Delete repeated words in comments lib/vdso: Allow to add architecture-specific vdso data timekeeping/vsyscall: Provide vdso_update_begin/end() vdso/treewide: Add vdso_data pointer argument to __arch_get_hw_counter()
2020-08-09Merge tag 'kbuild-v5.9' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild Pull Kbuild updates from Masahiro Yamada: - run the checker (e.g. sparse) after the compiler - remove unneeded cc-option tests for old compiler flags - fix tar-pkg to install dtbs - introduce ccflags-remove-y and asflags-remove-y syntax - allow to trace functions in sub-directories of lib/ - introduce hostprogs-always-y and userprogs-always-y syntax - various Makefile cleanups * tag 'kbuild-v5.9' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: kbuild: stop filtering out $(GCC_PLUGINS_CFLAGS) from cc-option base kbuild: include scripts/Makefile.* only when relevant CONFIG is enabled kbuild: introduce hostprogs-always-y and userprogs-always-y kbuild: sort hostprogs before passing it to ifneq kbuild: move host .so build rules to scripts/gcc-plugins/Makefile kbuild: Replace HTTP links with HTTPS ones kbuild: trace functions in subdirectories of lib/ kbuild: introduce ccflags-remove-y and asflags-remove-y kbuild: do not export LDFLAGS_vmlinux kbuild: always create directories of targets powerpc/boot: add DTB to 'targets' kbuild: buildtar: add dtbs support kbuild: remove cc-option test of -ffreestanding kbuild: remove cc-option test of -fno-stack-protector Revert "kbuild: Create directory for target DTB" kbuild: run the checker after the compiler
2020-08-06lib/vdso: Allow to add architecture-specific vdso dataSven Schnelle
The initial assumption that all VDSO related data can be completely generic does not hold. S390 needs architecture specific storage to access the clock steering information. Add struct arch_vdso_data to the vdso data struct. For architectures which do not need extra data this defaults to an empty struct. Architectures which require it, enable CONFIG_ARCH_HAS_VDSO_DATA and provide their specific struct in asm/vdso/data.h. Signed-off-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20200804150124.41692-2-svens@linux.ibm.com
2020-08-04Merge tag 'docs-5.9' of git://git.lwn.net/linuxLinus Torvalds
Pull documentation updates from Jonathan Corbet: "It's been a busy cycle for documentation - hopefully the busiest for a while to come. Changes include: - Some new Chinese translations - Progress on the battle against double words words and non-HTTPS URLs - Some block-mq documentation - More RST conversions from Mauro. At this point, that task is essentially complete, so we shouldn't see this kind of churn again for a while. Unless we decide to switch to asciidoc or something...:) - Lots of typo fixes, warning fixes, and more" * tag 'docs-5.9' of git://git.lwn.net/linux: (195 commits) scripts/kernel-doc: optionally treat warnings as errors docs: ia64: correct typo mailmap: add entry for <alobakin@marvell.com> doc/zh_CN: add cpu-load Chinese version Documentation/admin-guide: tainted-kernels: fix spelling mistake MAINTAINERS: adjust kprobes.rst entry to new location devices.txt: document rfkill allocation PCI: correct flag name docs: filesystems: vfs: correct flag name docs: filesystems: vfs: correct sync_mode flag names docs: path-lookup: markup fixes for emphasis docs: path-lookup: more markup fixes docs: path-lookup: fix HTML entity mojibake CREDITS: Replace HTTP links with HTTPS ones docs: process: Add an example for creating a fixes tag doc/zh_CN: add Chinese translation prefer section doc/zh_CN: add clearing-warn-once Chinese version doc/zh_CN: add admin-guide index doc:it_IT: process: coding-style.rst: Correct __maybe_unused compiler label futex: MAINTAINERS: Re-add selftests directory ...
2020-08-04Merge tag 'core-entry-2020-08-04' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull generic kernel entry/exit code from Thomas Gleixner: "Generic implementation of common syscall, interrupt and exception entry/exit functionality based on the recent X86 effort to ensure correctness of entry/exit vs RCU and instrumentation. As this functionality and the required entry/exit sequences are not architecture specific, sharing them allows other architectures to benefit instead of copying the same code over and over again. This branch was kept standalone to allow others to work on it. The conversion of x86 comes in a seperate pull request which obviously is based on this branch" * tag 'core-entry-2020-08-04' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: entry: Correct __secure_computing() stub entry: Correct 'noinstr' attributes entry: Provide infrastructure for work before transitioning to guest mode entry: Provide generic interrupt entry/exit code entry: Provide generic syscall exit function entry: Provide generic syscall entry functionality seccomp: Provide stub for __secure_computing()
2020-07-24entry: Provide generic syscall entry functionalityThomas Gleixner
On syscall entry certain work needs to be done: - Establish state (lockdep, context tracking, tracing) - Conditional work (ptrace, seccomp, audit...) This code is needlessly duplicated and different in all architectures. Provide a generic version based on the x86 implementation which has all the RCU and instrumentation bits right. As interrupt/exception entry from user space needs parts of the same functionality, provide a function for this as well. syscall_enter_from_user_mode() and irqentry_enter_from_user_mode() must be called right after the low level ASM entry. The calling code must be non-instrumentable. After the functions returns state is correct and the subsequent functions can be instrumented. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Kees Cook <keescook@chromium.org> Link: https://lkml.kernel.org/r/20200722220519.513463269@linutronix.de
2020-07-07kbuild: remove cc-option test of -fno-stack-protectorMasahiro Yamada
Some Makefiles already pass -fno-stack-protector unconditionally. For example, arch/arm64/kernel/vdso/Makefile, arch/x86/xen/Makefile. No problem report so far about hard-coding this option. So, we can assume all supported compilers know -fno-stack-protector. GCC 4.8 and Clang support this option (https://godbolt.org/z/_HDGzN) Get rid of cc-option from -fno-stack-protector. Remove CONFIG_CC_HAS_STACKPROTECTOR_NONE, which is always 'y'. Note: arch/mips/vdso/Makefile adds -fno-stack-protector twice, first unconditionally, and second conditionally. I removed the second one. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Reviewed-by: Kees Cook <keescook@chromium.org> Acked-by: Ard Biesheuvel <ardb@kernel.org> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
2020-07-04arch: remove HAVE_COPY_THREAD_TLSChristian Brauner
All architectures support copy_thread_tls() now, so remove the legacy copy_thread() function and the HAVE_COPY_THREAD_TLS config option. Everyone uses the same process creation calling convention based on copy_thread_tls() and struct kernel_clone_args. This will make it easier to maintain the core process creation code under kernel/, simplifies the callpaths and makes the identical for all architectures. Cc: linux-arch@vger.kernel.org Acked-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Acked-by: Greentime Hu <green.hu@gmail.com> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
2020-06-26docs: move other kAPI documents to core-apiMauro Carvalho Chehab
There are a number of random documents that seem to be describing some aspects of the core-api. Move them to such directory, adding them at the core-api/index.rst file. Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Link: https://lore.kernel.org/r/86d979ed183adb76af93a92f20189bccf97f0055.1592918949.git.mchehab+huawei@kernel.org Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-06-14treewide: replace '---help---' in Kconfig files with 'help'Masahiro Yamada
Since commit 84af7a6194e4 ("checkpatch: kconfig: prefer 'help' over '---help---'"), the number of '---help---' has been gradually decreasing, but there are still more than 2400 instances. This commit finishes the conversion. While I touched the lines, I also fixed the indentation. There are a variety of indentation styles found. a) 4 spaces + '---help---' b) 7 spaces + '---help---' c) 8 spaces + '---help---' d) 1 space + 1 tab + '---help---' e) 1 tab + '---help---' (correct indentation) f) 1 tab + 1 space + '---help---' g) 1 tab + 2 spaces + '---help---' In order to convert all of them to 1 tab + 'help', I ran the following commend: $ find . -name 'Kconfig*' | xargs sed -i 's/^[[:space:]]*---help---/\thelp/' Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>