- 23 8月, 2018 5 次提交
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由 Adrian Reber 提交于
The CHECKPOINT_RESTORE configuration option was introduced in 2012 and combined with EXPERT. CHECKPOINT_RESTORE is already enabled in many distribution kernels and also part of the defconfigs of various architectures. To make it easier for distributions to enable CHECKPOINT_RESTORE this removes EXPERT and moves the configuration option out of the EXPERT block. Link: http://lkml.kernel.org/r/20180712130733.11510-1-adrian@lisas.deSigned-off-by: NAdrian Reber <adrian@lisas.de> Acked-by: NOleg Nesterov <oleg@redhat.com> Reviewed-by: NHendrik Brueckner <brueckner@linux.ibm.com> Acked-by: NPavel Emelyanov <xemul@virtuozzo.com> Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: Andrei Vagin <avagin@virtuozzo.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Paul Menzel 提交于
Add a log message to `run_init_process()`. This log message serves two purposes. 1. If the init process is not specified on the Linux Kernel command line, the user sees, what file was chosen. 2. The time stamps shows exactly, when the Linux kernel handed over control to the init process. Link: http://lkml.kernel.org/r/b1fc97fa-4aa9-1904-ddb5-859e78995c41@molgen.mpg.deSigned-off-by: NPaul Menzel <pmenzel@molgen.mpg.de> Reviewed-by: NAndrew Morton <akpm@linux-foundation.org> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Randy Dunlap 提交于
Correct typos of "it's" to "its. Link: http://lkml.kernel.org/r/0ac627b6-5527-55f4-0489-1631aa34fc11@infradead.orgSigned-off-by: NRandy Dunlap <rdunlap@infradead.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Luc Van Oostenryck 提交于
Sparse checking used to be disabled on init/do_mounts.c and a few related files because "Many of the syscalls used in this file expect some of the arguments to be __user pointers not __kernel pointers". However since 28128c61 ("kconfig.h: Include compiler types to avoid missed struct attributes") the checks are, in fact, not disabled anymore because of the more early include of "linux/compiler_types.h" So remove the now ineffective #undefery that was done to disable these warnings, as well as the associated comment. Link: http://lkml.kernel.org/r/20180617115355.53799-1-luc.vanoostenryck@gmail.comSigned-off-by: NLuc Van Oostenryck <luc.vanoostenryck@gmail.com> Cc: Dominik Brodowski <linux@dominikbrodowski.net> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Kees Cook <keescook@chromium.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Ard Biesheuvel 提交于
Allow the initcall tables to be emitted using relative references that are only half the size on 64-bit architectures and don't require fixups at runtime on relocatable kernels. Link: http://lkml.kernel.org/r/20180704083651.24360-5-ard.biesheuvel@linaro.orgAcked-by: NJames Morris <james.morris@microsoft.com> Acked-by: NSergey Senozhatsky <sergey.senozhatsky@gmail.com> Acked-by: NPetr Mladek <pmladek@suse.com> Acked-by: NMichael Ellerman <mpe@ellerman.id.au> Acked-by: NIngo Molnar <mingo@kernel.org> Signed-off-by: NArd Biesheuvel <ard.biesheuvel@linaro.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: James Morris <jmorris@namei.org> Cc: Jessica Yu <jeyu@kernel.org> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Kees Cook <keescook@chromium.org> Cc: Nicolas Pitre <nico@linaro.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Russell King <linux@armlinux.org.uk> Cc: "Serge E. Hallyn" <serge@hallyn.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Garnier <thgarnie@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 18 8月, 2018 1 次提交
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由 Kirill Tkhai 提交于
Introduce new config option, which is used to replace repeating CONFIG_MEMCG && !CONFIG_SLOB pattern. Next patches add a little more memcg+kmem related code, so let's keep the defines more clearly. Link: http://lkml.kernel.org/r/153063053670.1818.15013136946600481138.stgit@localhost.localdomainSigned-off-by: NKirill Tkhai <ktkhai@virtuozzo.com> Acked-by: NVladimir Davydov <vdavydov.dev@gmail.com> Tested-by: NShakeel Butt <shakeelb@google.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Chris Wilson <chris@chris-wilson.co.uk> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Guenter Roeck <linux@roeck-us.net> Cc: "Huang, Ying" <ying.huang@intel.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Josef Bacik <jbacik@fb.com> Cc: Li RongQing <lirongqing@baidu.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Matthias Kaehlcke <mka@chromium.org> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Michal Hocko <mhocko@kernel.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Philippe Ombredanne <pombredanne@nexb.com> Cc: Roman Gushchin <guro@fb.com> Cc: Sahitya Tummala <stummala@codeaurora.org> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Waiman Long <longman@redhat.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 13 8月, 2018 1 次提交
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由 Linus Torvalds 提交于
This is purely a preparatory patch for upcoming changes during the 4.19 merge window. We have a function called "boot_cpu_state_init()" that isn't really about the bootup cpu state: that is done much earlier by the similarly named "boot_cpu_init()" (note lack of "state" in name). This function initializes some hotplug CPU state, and needs to run after the percpu data has been properly initialized. It even has a comment to that effect. Except it _doesn't_ actually run after the percpu data has been properly initialized. On x86 it happens to do that, but on at least arm and arm64, the percpu base pointers are initialized by the arch-specific 'smp_prepare_boot_cpu()' hook, which ran _after_ boot_cpu_state_init(). This had some unexpected results, and in particular we have a patch pending for the merge window that did the obvious cleanup of using 'this_cpu_write()' in the cpu hotplug init code: - per_cpu_ptr(&cpuhp_state, smp_processor_id())->state = CPUHP_ONLINE; + this_cpu_write(cpuhp_state.state, CPUHP_ONLINE); which is obviously the right thing to do. Except because of the ordering issue, it actually failed miserably and unexpectedly on arm64. So this just fixes the ordering, and changes the name of the function to be 'boot_cpu_hotplug_init()' to make it obvious that it's about cpu hotplug state, because the core CPU state was supposed to have already been done earlier. Marked for stable, since the (not yet merged) patch that will show this problem is marked for stable. Reported-by: NVlastimil Babka <vbabka@suse.cz> Reported-by: NMian Yousaf Kaukab <yousaf.kaukab@suse.com> Suggested-by: NCatalin Marinas <catalin.marinas@arm.com> Acked-by: NThomas Gleixner <tglx@linutronix.de> Cc: Will Deacon <will.deacon@arm.com> Cc: stable@kernel.org Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 11 8月, 2018 1 次提交
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由 Steven Rostedt (VMware) 提交于
Joel Fernandes created a nice patch that cleaned up the duplicate hooks used by lockdep and irqsoff latency tracer. It made both use tracepoints. But it caused lockdep to trigger several false positives. We have not figured out why yet, but removing lockdep from using the trace event hooks and just call its helper functions directly (like it use to), makes the problem go away. This is a partial revert of the clean up patch c3bc8fd6 ("tracing: Centralize preemptirq tracepoints and unify their usage") that adds direct calls for lockdep, but also keeps most of the clean up done to get rid of the horrible preprocessor if statements. Link: http://lkml.kernel.org/r/20180806155058.5ee875f4@gandalf.local.home Cc: Peter Zijlstra <peterz@infradead.org> Reviewed-by: NJoel Fernandes (Google) <joel@joelfernandes.org> Fixes: c3bc8fd6 ("tracing: Centralize preemptirq tracepoints and unify their usage") Signed-off-by: NSteven Rostedt (VMware) <rostedt@goodmis.org>
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- 09 8月, 2018 1 次提交
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由 Rob Landley 提交于
Avoids warning messages with the latest release of toybox, which never bothered to implement the --longopts nothing was using. Signed-off-by: NRob Landley <rob@landley.net> Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
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- 02 8月, 2018 3 次提交
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由 Christoph Hellwig 提交于
Almost all architectures include it. Add a ARCH_NO_PREEMPT symbol to disable preempt support for alpha, hexagon, non-coldfire m68k and user mode Linux. Signed-off-by: NChristoph Hellwig <hch@lst.de> Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
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由 Christoph Hellwig 提交于
Instead of duplicating the source statements in every architecture just do it once in the toplevel Kconfig file. Note that with this the inclusion of arch/$(SRCARCH/Kconfig moves out of the top-level Kconfig into arch/Kconfig so that don't violate ordering constraits while keeping a sensible menu structure. Signed-off-by: NChristoph Hellwig <hch@lst.de> Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
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由 Christoph Hellwig 提交于
microblaze and nios2 define their own always n SWAP symbols. Remove those and let the generic defintion do the right thing by adding a new symbol to disable swap entirely. Signed-off-by: NChristoph Hellwig <hch@lst.de> Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
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- 31 7月, 2018 1 次提交
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由 Joel Fernandes (Google) 提交于
This patch detaches the preemptirq tracepoints from the tracers and keeps it separate. Advantages: * Lockdep and irqsoff event can now run in parallel since they no longer have their own calls. * This unifies the usecase of adding hooks to an irqsoff and irqson event, and a preemptoff and preempton event. 3 users of the events exist: - Lockdep - irqsoff and preemptoff tracers - irqs and preempt trace events The unification cleans up several ifdefs and makes the code in preempt tracer and irqsoff tracers simpler. It gets rid of all the horrific ifdeferry around PROVE_LOCKING and makes configuration of the different users of the tracepoints more easy and understandable. It also gets rid of the time_* function calls from the lockdep hooks used to call into the preemptirq tracer which is not needed anymore. The negative delta in lines of code in this patch is quite large too. In the patch we introduce a new CONFIG option PREEMPTIRQ_TRACEPOINTS as a single point for registering probes onto the tracepoints. With this, the web of config options for preempt/irq toggle tracepoints and its users becomes: PREEMPT_TRACER PREEMPTIRQ_EVENTS IRQSOFF_TRACER PROVE_LOCKING | | \ | | \ (selects) / \ \ (selects) / TRACE_PREEMPT_TOGGLE ----> TRACE_IRQFLAGS \ / \ (depends on) / PREEMPTIRQ_TRACEPOINTS Other than the performance tests mentioned in the previous patch, I also ran the locking API test suite. I verified that all tests cases are passing. I also injected issues by not registering lockdep probes onto the tracepoints and I see failures to confirm that the probes are indeed working. This series + lockdep probes not registered (just to inject errors): [ 0.000000] hard-irqs-on + irq-safe-A/21: ok | ok | ok | [ 0.000000] soft-irqs-on + irq-safe-A/21: ok | ok | ok | [ 0.000000] sirq-safe-A => hirqs-on/12:FAILED|FAILED| ok | [ 0.000000] sirq-safe-A => hirqs-on/21:FAILED|FAILED| ok | [ 0.000000] hard-safe-A + irqs-on/12:FAILED|FAILED| ok | [ 0.000000] soft-safe-A + irqs-on/12:FAILED|FAILED| ok | [ 0.000000] hard-safe-A + irqs-on/21:FAILED|FAILED| ok | [ 0.000000] soft-safe-A + irqs-on/21:FAILED|FAILED| ok | [ 0.000000] hard-safe-A + unsafe-B #1/123: ok | ok | ok | [ 0.000000] soft-safe-A + unsafe-B #1/123: ok | ok | ok | With this series + lockdep probes registered, all locking tests pass: [ 0.000000] hard-irqs-on + irq-safe-A/21: ok | ok | ok | [ 0.000000] soft-irqs-on + irq-safe-A/21: ok | ok | ok | [ 0.000000] sirq-safe-A => hirqs-on/12: ok | ok | ok | [ 0.000000] sirq-safe-A => hirqs-on/21: ok | ok | ok | [ 0.000000] hard-safe-A + irqs-on/12: ok | ok | ok | [ 0.000000] soft-safe-A + irqs-on/12: ok | ok | ok | [ 0.000000] hard-safe-A + irqs-on/21: ok | ok | ok | [ 0.000000] soft-safe-A + irqs-on/21: ok | ok | ok | [ 0.000000] hard-safe-A + unsafe-B #1/123: ok | ok | ok | [ 0.000000] soft-safe-A + unsafe-B #1/123: ok | ok | ok | Link: http://lkml.kernel.org/r/20180730222423.196630-4-joel@joelfernandes.orgAcked-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: NNamhyung Kim <namhyung@kernel.org> Signed-off-by: NJoel Fernandes (Google) <joel@joelfernandes.org> Signed-off-by: NSteven Rostedt (VMware) <rostedt@goodmis.org>
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- 20 7月, 2018 3 次提交
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由 Joerg Roedel 提交于
Introduce a new function to finalize the kernel mappings for the userspace page-table after all ro/nx protections have been applied to the kernel mappings. Also move the call to pti_clone_kernel_text() to that function so that it will run on 32 bit kernels too. Signed-off-by: NJoerg Roedel <jroedel@suse.de> Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Tested-by: NPavel Machek <pavel@ucw.cz> Cc: "H . Peter Anvin" <hpa@zytor.com> Cc: linux-mm@kvack.org Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Jiri Kosina <jkosina@suse.cz> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Brian Gerst <brgerst@gmail.com> Cc: David Laight <David.Laight@aculab.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Eduardo Valentin <eduval@amazon.com> Cc: Greg KH <gregkh@linuxfoundation.org> Cc: Will Deacon <will.deacon@arm.com> Cc: aliguori@amazon.com Cc: daniel.gruss@iaik.tugraz.at Cc: hughd@google.com Cc: keescook@google.com Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Waiman Long <llong@redhat.com> Cc: "David H . Gutteridge" <dhgutteridge@sympatico.ca> Cc: joro@8bytes.org Link: https://lkml.kernel.org/r/1531906876-13451-30-git-send-email-joro@8bytes.org
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由 Pavel Tatashin 提交于
Allow sched_clock() to be used before schec_clock_init() is called. This provides a way to get early boot timestamps on machines with unstable clocks. Signed-off-by: NPavel Tatashin <pasha.tatashin@oracle.com> Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Cc: steven.sistare@oracle.com Cc: daniel.m.jordan@oracle.com Cc: linux@armlinux.org.uk Cc: schwidefsky@de.ibm.com Cc: heiko.carstens@de.ibm.com Cc: john.stultz@linaro.org Cc: sboyd@codeaurora.org Cc: hpa@zytor.com Cc: douly.fnst@cn.fujitsu.com Cc: peterz@infradead.org Cc: prarit@redhat.com Cc: feng.tang@intel.com Cc: pmladek@suse.com Cc: gnomes@lxorguk.ukuu.org.uk Cc: linux-s390@vger.kernel.org Cc: boris.ostrovsky@oracle.com Cc: jgross@suse.com Cc: pbonzini@redhat.com Link: https://lkml.kernel.org/r/20180719205545.16512-24-pasha.tatashin@oracle.com
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由 Pavel Tatashin 提交于
sched_clock_postinit() initializes a generic clock on systems where no other clock is provided. This function may be called only after timekeeping_init(). Rename sched_clock_postinit to generic_clock_inti() and call it from sched_clock_init(). Move the call for sched_clock_init() until after time_init(). Suggested-by: NPeter Zijlstra <peterz@infradead.org> Signed-off-by: NPavel Tatashin <pasha.tatashin@oracle.com> Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Cc: steven.sistare@oracle.com Cc: daniel.m.jordan@oracle.com Cc: linux@armlinux.org.uk Cc: schwidefsky@de.ibm.com Cc: heiko.carstens@de.ibm.com Cc: john.stultz@linaro.org Cc: sboyd@codeaurora.org Cc: hpa@zytor.com Cc: douly.fnst@cn.fujitsu.com Cc: prarit@redhat.com Cc: feng.tang@intel.com Cc: pmladek@suse.com Cc: gnomes@lxorguk.ukuu.org.uk Cc: linux-s390@vger.kernel.org Cc: boris.ostrovsky@oracle.com Cc: jgross@suse.com Cc: pbonzini@redhat.com Link: https://lkml.kernel.org/r/20180719205545.16512-23-pasha.tatashin@oracle.com
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- 18 7月, 2018 1 次提交
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由 Laura Abbott 提交于
In Fedora, the debug information is packaged separately (foo-debuginfo) and can be installed separately. There's been a long standing issue where only one version of a debuginfo info package can be installed at a time. There's been an effort for Fedora for parallel debuginfo to rectify this problem. Part of the requirement to allow parallel debuginfo to work is that build ids are unique between builds. The existing upstream rpm implementation ensures this by re-calculating the build-id using the version and release as a seed. This doesn't work 100% for the kernel because of the vDSO which is its own binary and doesn't get updated when embedded. Fix this by adding some data in an ELF note for both the kernel and modules. The data is controlled via a Kconfig option so distributions can set it to an appropriate value to ensure uniqueness between builds. Suggested-by: NMasahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by: NLaura Abbott <labbott@redhat.com> Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
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- 28 6月, 2018 1 次提交
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由 Masahiro Yamada 提交于
Since commit 5d20ee31 ("kbuild: Allow LD_DEAD_CODE_DATA_ELIMINATION to be selectable if enabled"), HAVE_LD_DEAD_CODE_DATA_ELIMINATION is supposed to be selected by architectures that are capable of this functionality. LD_DEAD_CODE_DATA_ELIMINATION is now users' selection. Update the help message. Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
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- 25 6月, 2018 1 次提交
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由 Vasily Gorbik 提交于
Add "None" as the kernel compression mode. This option is useful for debugging the kernel in slow simulation environments, where decompressing and moving the kernel is awfully slow. Uncompressed kernel implementation might allow early boot code to skip the decompressor and jump right at uncompressed kernel image entry point. Platforms implementing that should define HAVE_KERNEL_UNCOMPRESSED. Reviewed-by: NHeiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: NVasily Gorbik <gor@linux.ibm.com> Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
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- 14 6月, 2018 1 次提交
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由 Christoph Hellwig 提交于
Currently the code is split over various files with dma- prefixes in the lib/ and drives/base directories, and the number of files keeps growing. Move them into a single directory to keep the code together and remove the file name prefixes. To match the irq infrastructure this directory is placed under the kernel/ directory. Signed-off-by: NChristoph Hellwig <hch@lst.de>
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- 08 6月, 2018 2 次提交
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由 Masahiro Yamada 提交于
This will be useful to describe the clang version dependency. Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com> Reviewed-by: NKees Cook <keescook@chromium.org>
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由 Masahiro Yamada 提交于
This will be useful to specify the required compiler version, like this: config FOO bool "Use Foo" depends on GCC_VERSION >= 40800 help This feature requires GCC 4.8 or newer. Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com> Reviewed-by: NKees Cook <keescook@chromium.org>
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- 06 6月, 2018 1 次提交
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由 Mathieu Desnoyers 提交于
Expose a new system call allowing each thread to register one userspace memory area to be used as an ABI between kernel and user-space for two purposes: user-space restartable sequences and quick access to read the current CPU number value from user-space. * Restartable sequences (per-cpu atomics) Restartables sequences allow user-space to perform update operations on per-cpu data without requiring heavy-weight atomic operations. The restartable critical sections (percpu atomics) work has been started by Paul Turner and Andrew Hunter. It lets the kernel handle restart of critical sections. [1] [2] The re-implementation proposed here brings a few simplifications to the ABI which facilitates porting to other architectures and speeds up the user-space fast path. Here are benchmarks of various rseq use-cases. Test hardware: arm32: ARMv7 Processor rev 4 (v7l) "Cubietruck", 2-core x86-64: Intel E5-2630 v3@2.40GHz, 16-core, hyperthreading The following benchmarks were all performed on a single thread. * Per-CPU statistic counter increment getcpu+atomic (ns/op) rseq (ns/op) speedup arm32: 344.0 31.4 11.0 x86-64: 15.3 2.0 7.7 * LTTng-UST: write event 32-bit header, 32-bit payload into tracer per-cpu buffer getcpu+atomic (ns/op) rseq (ns/op) speedup arm32: 2502.0 2250.0 1.1 x86-64: 117.4 98.0 1.2 * liburcu percpu: lock-unlock pair, dereference, read/compare word getcpu+atomic (ns/op) rseq (ns/op) speedup arm32: 751.0 128.5 5.8 x86-64: 53.4 28.6 1.9 * jemalloc memory allocator adapted to use rseq Using rseq with per-cpu memory pools in jemalloc at Facebook (based on rseq 2016 implementation): The production workload response-time has 1-2% gain avg. latency, and the P99 overall latency drops by 2-3%. * Reading the current CPU number Speeding up reading the current CPU number on which the caller thread is running is done by keeping the current CPU number up do date within the cpu_id field of the memory area registered by the thread. This is done by making scheduler preemption set the TIF_NOTIFY_RESUME flag on the current thread. Upon return to user-space, a notify-resume handler updates the current CPU value within the registered user-space memory area. User-space can then read the current CPU number directly from memory. Keeping the current cpu id in a memory area shared between kernel and user-space is an improvement over current mechanisms available to read the current CPU number, which has the following benefits over alternative approaches: - 35x speedup on ARM vs system call through glibc - 20x speedup on x86 compared to calling glibc, which calls vdso executing a "lsl" instruction, - 14x speedup on x86 compared to inlined "lsl" instruction, - Unlike vdso approaches, this cpu_id value can be read from an inline assembly, which makes it a useful building block for restartable sequences. - The approach of reading the cpu id through memory mapping shared between kernel and user-space is portable (e.g. ARM), which is not the case for the lsl-based x86 vdso. On x86, yet another possible approach would be to use the gs segment selector to point to user-space per-cpu data. This approach performs similarly to the cpu id cache, but it has two disadvantages: it is not portable, and it is incompatible with existing applications already using the gs segment selector for other purposes. Benchmarking various approaches for reading the current CPU number: ARMv7 Processor rev 4 (v7l) Machine model: Cubietruck - Baseline (empty loop): 8.4 ns - Read CPU from rseq cpu_id: 16.7 ns - Read CPU from rseq cpu_id (lazy register): 19.8 ns - glibc 2.19-0ubuntu6.6 getcpu: 301.8 ns - getcpu system call: 234.9 ns x86-64 Intel(R) Xeon(R) CPU E5-2630 v3 @ 2.40GHz: - Baseline (empty loop): 0.8 ns - Read CPU from rseq cpu_id: 0.8 ns - Read CPU from rseq cpu_id (lazy register): 0.8 ns - Read using gs segment selector: 0.8 ns - "lsl" inline assembly: 13.0 ns - glibc 2.19-0ubuntu6 getcpu: 16.6 ns - getcpu system call: 53.9 ns - Speed (benchmark taken on v8 of patchset) Running 10 runs of hackbench -l 100000 seems to indicate, contrary to expectations, that enabling CONFIG_RSEQ slightly accelerates the scheduler: Configuration: 2 sockets * 8-core Intel(R) Xeon(R) CPU E5-2630 v3 @ 2.40GHz (directly on hardware, hyperthreading disabled in BIOS, energy saving disabled in BIOS, turboboost disabled in BIOS, cpuidle.off=1 kernel parameter), with a Linux v4.6 defconfig+localyesconfig, restartable sequences series applied. * CONFIG_RSEQ=n avg.: 41.37 s std.dev.: 0.36 s * CONFIG_RSEQ=y avg.: 40.46 s std.dev.: 0.33 s - Size On x86-64, between CONFIG_RSEQ=n/y, the text size increase of vmlinux is 567 bytes, and the data size increase of vmlinux is 5696 bytes. [1] https://lwn.net/Articles/650333/ [2] http://www.linuxplumbersconf.org/2013/ocw/system/presentations/1695/original/LPC%20-%20PerCpu%20Atomics.pdfSigned-off-by: NMathieu Desnoyers <mathieu.desnoyers@efficios.com> Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Acked-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Cc: Joel Fernandes <joelaf@google.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Dave Watson <davejwatson@fb.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: "H . Peter Anvin" <hpa@zytor.com> Cc: Chris Lameter <cl@linux.com> Cc: Russell King <linux@arm.linux.org.uk> Cc: Andrew Hunter <ahh@google.com> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: "Paul E . McKenney" <paulmck@linux.vnet.ibm.com> Cc: Paul Turner <pjt@google.com> Cc: Boqun Feng <boqun.feng@gmail.com> Cc: Josh Triplett <josh@joshtriplett.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Ben Maurer <bmaurer@fb.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: linux-api@vger.kernel.org Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/20151027235635.16059.11630.stgit@pjt-glaptop.roam.corp.google.com Link: http://lkml.kernel.org/r/20150624222609.6116.86035.stgit@kitami.mtv.corp.google.com Link: https://lkml.kernel.org/r/20180602124408.8430-3-mathieu.desnoyers@efficios.com
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- 29 5月, 2018 3 次提交
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由 Masahiro Yamada 提交于
Now that 'shell' function is supported, this can be self-contained in Kconfig. Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com> Reviewed-by: NKees Cook <keescook@chromium.org> Reviewed-by: NUlf Magnusson <ulfalizer@gmail.com>
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由 Masahiro Yamada 提交于
To get access to environment variables, Kconfig needs to define a symbol using "option env=" syntax. It is tedious to add a symbol entry for each environment variable given that we need to define much more such as 'CC', 'AS', 'srctree' etc. to evaluate the compiler capability in Kconfig. Adding '$' for symbol references is grammatically inconsistent. Looking at the code, the symbols prefixed with 'S' are expanded by: - conf_expand_value() This is used to expand 'arch/$ARCH/defconfig' and 'defconfig_list' - sym_expand_string_value() This is used to expand strings in 'source' and 'mainmenu' All of them are fixed values independent of user configuration. So, they can be changed into the direct expansion instead of symbols. This change makes the code much cleaner. The bounce symbols 'SRCARCH', 'ARCH', 'SUBARCH', 'KERNELVERSION' are gone. sym_init() hard-coding 'UNAME_RELEASE' is also gone. 'UNAME_RELEASE' should be replaced with an environment variable. ARCH_DEFCONFIG is a normal symbol, so it should be simply referenced without '$' prefix. The new syntax is addicted by Make. The variable reference needs parentheses, like $(FOO), but you can omit them for single-letter variables, like $F. Yet, in Makefiles, people tend to use the parenthetical form for consistency / clarification. At this moment, only the environment variable is supported, but I will extend the concept of 'variable' later on. The variables are expanded in the lexer so we can simplify the token handling on the parser side. For example, the following code works. [Example code] config MY_TOOLCHAIN_LIST string default "My tools: CC=$(CC), AS=$(AS), CPP=$(CPP)" [Result] $ make -s alldefconfig && tail -n 1 .config CONFIG_MY_TOOLCHAIN_LIST="My tools: CC=gcc, AS=as, CPP=gcc -E" Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com> Reviewed-by: NKees Cook <keescook@chromium.org>
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由 Masahiro Yamada 提交于
Kbuild provides a couple of ways to specify CROSS_COMPILE: [1] Command line [2] Environment [3] arch/*/Makefile (only some architectures) [4] CONFIG_CROSS_COMPILE [4] is problematic for the compiler capability tests in Kconfig. CONFIG_CROSS_COMPILE allows users to change the compiler prefix from 'make menuconfig', etc. It means, the compiler options would have to be all re-calculated everytime CONFIG_CROSS_COMPILE is changed. To avoid complexity and performance issues, I'd like to evaluate the shell commands statically, i.e. only parsing Kconfig files. I guess the majority is [1] or [2]. Currently, there are only 5 defconfig files that specify CONFIG_CROSS_COMPILE. arch/arm/configs/lpc18xx_defconfig arch/hexagon/configs/comet_defconfig arch/nds32/configs/defconfig arch/openrisc/configs/or1ksim_defconfig arch/openrisc/configs/simple_smp_defconfig Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com> Reviewed-by: NKees Cook <keescook@chromium.org>
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- 26 5月, 2018 1 次提交
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由 Mathieu Malaterre 提交于
In commit c7753208 ("x86, swiotlb: Add memory encryption support") a call to function `mem_encrypt_init' was added. Include prototype defined in header <linux/mem_encrypt.h> to prevent a warning reported during compilation with W=1: init/main.c:494:20: warning: no previous prototype for `mem_encrypt_init' [-Wmissing-prototypes] Link: http://lkml.kernel.org/r/20180522195533.31415-1-malat@debian.orgSigned-off-by: NMathieu Malaterre <malat@debian.org> Reviewed-by: NAndrew Morton <akpm@linux-foundation.org> Acked-by: NSteven Rostedt (VMware) <rostedt@goodmis.org> Cc: Tom Lendacky <thomas.lendacky@amd.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Kees Cook <keescook@chromium.org> Cc: Laura Abbott <lauraa@codeaurora.org> Cc: Dominik Brodowski <linux@dominikbrodowski.net> Cc: Gargi Sharma <gs051095@gmail.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 18 5月, 2018 1 次提交
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The 'tip' prefix probably referred to the -tip tree and is not required, remove it. Signed-off-by: NSebastian Andrzej Siewior <bigeasy@linutronix.de> Acked-by: NPeter Zijlstra <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul Turner <pjt@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20180515165328.24899-1-bigeasy@linutronix.deSigned-off-by: NIngo Molnar <mingo@kernel.org>
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- 17 5月, 2018 1 次提交
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由 Nicholas Piggin 提交于
Architectures that are capable can select HAVE_LD_DEAD_CODE_DATA_ELIMINATION to enable selection of that option (as an EXPERT kernel option). Signed-off-by: NNicholas Piggin <npiggin@gmail.com> Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
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- 15 5月, 2018 2 次提交
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由 Song Liu 提交于
Currently, we cannot parse build_id in nmi context because of up_read(¤t->mm->mmap_sem), this makes stackmap with build_id less useful. This patch enables parsing build_id in nmi by putting the up_read() call in irq_work. To avoid memory allocation in nmi context, we use per cpu variable for the irq_work. As a result, only one irq_work per cpu is allowed. If the irq_work is in-use, we fallback to only report ips. Cc: Alexei Starovoitov <ast@kernel.org> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: NSong Liu <songliubraving@fb.com> Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
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由 Richard Guy Briggs 提交于
Use a macro, "AUDIT_SID_UNSET", to replace each instance of initialization and comparison to an audit session ID. Signed-off-by: NRichard Guy Briggs <rgb@redhat.com> Signed-off-by: NPaul Moore <paul@paul-moore.com>
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- 12 5月, 2018 1 次提交
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由 Jeffrey Hugo 提交于
load_module() creates W+X mappings via __vmalloc_node_range() (from layout_and_allocate()->move_module()->module_alloc()) by using PAGE_KERNEL_EXEC. These mappings are later cleaned up via "call_rcu_sched(&freeinit->rcu, do_free_init)" from do_init_module(). This is a problem because call_rcu_sched() queues work, which can be run after debug_checkwx() is run, resulting in a race condition. If hit, the race results in a nasty splat about insecure W+X mappings, which results in a poor user experience as these are not the mappings that debug_checkwx() is intended to catch. This issue is observed on multiple arm64 platforms, and has been artificially triggered on an x86 platform. Address the race by flushing the queued work before running the arch-defined mark_rodata_ro() which then calls debug_checkwx(). Link: http://lkml.kernel.org/r/1525103946-29526-1-git-send-email-jhugo@codeaurora.org Fixes: e1a58320 ("x86/mm: Warn on W^X mappings") Signed-off-by: NJeffrey Hugo <jhugo@codeaurora.org> Reported-by: NTimur Tabi <timur@codeaurora.org> Reported-by: NJan Glauber <jan.glauber@caviumnetworks.com> Acked-by: NKees Cook <keescook@chromium.org> Acked-by: NIngo Molnar <mingo@kernel.org> Acked-by: NWill Deacon <will.deacon@arm.com> Acked-by: NLaura Abbott <labbott@redhat.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Stephen Smalley <sds@tycho.nsa.gov> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 07 5月, 2018 1 次提交
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由 Florian La Roche 提交于
CONFIG_PRREMPT -> CONFIG_PREEMPT Signed-off-by: NFlorian La Roche <Florian.LaRoche@googlemail.com> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 12 4月, 2018 3 次提交
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由 Alexey Dobriyan 提交于
For fine-grained debugging and usercopy protection. Link: http://lkml.kernel.org/r/20180310085027.GA17121@avx2Signed-off-by: NAlexey Dobriyan <adobriyan@gmail.com> Reviewed-by: NAndrew Morton <akpm@linux-foundation.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Glauber Costa <glommer@gmail.com> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Aaro Koskinen 提交于
Use pr_cont() at the end of ramdisk loading. This will avoid the rotator and an extra newline appearing in the dmesg. Before: RAMDISK: Loading 2436KiB [1 disk] into ram disk... | done. After: RAMDISK: Loading 2436KiB [1 disk] into ram disk... done. Link: http://lkml.kernel.org/r/20180302205552.16031-1-aaro.koskinen@iki.fiSigned-off-by: NAaro Koskinen <aaro.koskinen@iki.fi> Reviewed-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Alexey Dobriyan 提交于
So "struct uts_namespace" can enjoy fine-grained SLAB debugging and usercopy protection. I'd prefer shorter name "utsns" but there is "user_namespace" already. Link: http://lkml.kernel.org/r/20180228215158.GA23146@avx2Signed-off-by: NAlexey Dobriyan <adobriyan@gmail.com> Reviewed-by: NAndrew Morton <akpm@linux-foundation.org> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Serge Hallyn <serge@hallyn.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 08 4月, 2018 1 次提交
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由 Steven Rostedt (VMware) 提交于
Add macros around the initcall_debug tracepoint code to have the code to default back to the old method if CONFIG_TRACEPOINTS is not enabled. Signed-off-by: NSteven Rostedt (VMware) <rostedt@goodmis.org>
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- 06 4月, 2018 2 次提交
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由 Steven Rostedt (VMware) 提交于
With trace events set before and after the initcall function calls, instead of having a separate routine for printing out the initcalls when initcall_debug is specified on the kernel command line, have the code register a callback to the tracepoints where the initcall trace events are. This removes the need for having a separate function to do the initcalls as the tracepoint callbacks can handle the printk. It also includes other initcalls that are not called by the do_one_initcall() which includes console and security initcalls. Signed-off-by: NSteven Rostedt (VMware) <rostedt@goodmis.org>
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由 Steven Rostedt (VMware) 提交于
Being able to trace the start and stop of initcalls is useful to see where the timings are an issue. There is already an "initcall_debug" parameter, but that can cause a large overhead itself, as the printing of the information may take longer than the initcall functions. Adding in a start and finish trace event around the initcall functions, as well as a trace event that records the level of the initcalls, one can get a much finer measurement of the times and interactions of the initcalls themselves, as trace events are much lighter than printk()s. Suggested-by: NAbderrahmane Benbachir <abderrahmane.benbachir@polymtl.ca> Signed-off-by: NSteven Rostedt (VMware) <rostedt@goodmis.org>
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- 05 4月, 2018 1 次提交
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由 Dominik Brodowski 提交于
It may be useful for an architecture to override the definitions of the COMPAT_SYSCALL_DEFINE0() and __COMPAT_SYSCALL_DEFINEx() macros in <linux/compat.h>, in particular to use a different calling convention for syscalls. This patch provides a mechanism to do so, based on the previously introduced CONFIG_ARCH_HAS_SYSCALL_WRAPPER. If it is enabled, <asm/sycall_wrapper.h> is included in <linux/compat.h> and may be used to define the macros mentioned above. Moreover, as the syscall calling convention may be different if CONFIG_ARCH_HAS_SYSCALL_WRAPPER is set, the compat syscall function prototypes in <linux/compat.h> are #ifndef'd out in that case. As some of the syscalls and/or compat syscalls may not be present, the COND_SYSCALL() and COND_SYSCALL_COMPAT() macros in kernel/sys_ni.c as well as the SYS_NI() and COMPAT_SYS_NI() macros in kernel/time/posix-stubs.c can be re-defined in <asm/syscall_wrapper.h> iff CONFIG_ARCH_HAS_SYSCALL_WRAPPER is enabled. Signed-off-by: NDominik Brodowski <linux@dominikbrodowski.net> Acked-by: NLinus Torvalds <torvalds@linux-foundation.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20180405095307.3730-5-linux@dominikbrodowski.netSigned-off-by: NIngo Molnar <mingo@kernel.org>
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