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2014-08-15module: Clean up ro/nx after early module load failuresAndy Lutomirski
The commit 4982223e51e8 module: set nx before marking module MODULE_STATE_COMING. introduced a regression: if a module fails to parse its arguments or if mod_sysfs_setup fails, then the module's memory will be freed while still read-only. Anything that reuses that memory will crash as soon as it tries to write to it. Cc: stable@vger.kernel.org # v3.16 Cc: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Andy Lutomirski <luto@amacapital.net> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2014-08-15Merge tag 'pm+acpi-3.17-rc1-2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm Pull more ACPI and power management updates from Rafael Wysocki: "These are a couple of regression fixes, cpuidle menu governor optimizations, fixes for ACPI proccessor and battery drivers, hibernation fix to avoid problems related to the e820 memory map, fixes for a few cpufreq drivers and a new version of the suspend profiling tool analyze_suspend.py. Specifics: - Fix for an ACPI-based device hotplug regression introduced in 3.14 that causes a kernel panic to trigger when memory hot-remove is attempted with CONFIG_ACPI_HOTPLUG_MEMORY unset from Tang Chen - Fix for a cpufreq regression introduced in 3.16 that triggers a "sleeping function called from invalid context" bug in dev_pm_opp_init_cpufreq_table() from Stephen Boyd - ACPI battery driver fix for a warning message added in 3.16 that prints silly stuff sometimes from Mariusz Ceier - Hibernation fix for safer handling of mismatches in the 820 memory map between the configurations during image creation and during the subsequent restore from Chun-Yi Lee - ACPI processor driver fix to handle CPU hotplug notifications correctly during system suspend/resume from Lan Tianyu - Series of four cpuidle menu governor cleanups that also should speed it up a bit from Mel Gorman - Fixes for the speedstep-smi, integrator, cpu0 and arm_big_little cpufreq drivers from Hans Wennborg, Himangi Saraogi, Markus Pargmann and Uwe Kleine-König - Version 3.0 of the analyze_suspend.py suspend profiling tool from Todd E Brandt" * tag 'pm+acpi-3.17-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: ACPI / battery: Fix warning message in acpi_battery_get_state() PM / tools: analyze_suspend.py: update to v3.0 cpufreq: arm_big_little: fix module license spec cpufreq: speedstep-smi: fix decimal printf specifiers ACPI / hotplug: Check scan handlers in acpi_scan_hot_remove() cpufreq: OPP: Avoid sleeping while atomic cpufreq: cpu0: Do not print error message when deferring cpufreq: integrator: Use set_cpus_allowed_ptr PM / hibernate: avoid unsafe pages in e820 reserved regions ACPI / processor: Make acpi_cpu_soft_notify() process CPU FROZEN events cpuidle: menu: Lookup CPU runqueues less cpuidle: menu: Call nr_iowait_cpu less times cpuidle: menu: Use ktime_to_us instead of reinventing the wheel cpuidle: menu: Use shifts when calculating averages where possible
2014-08-14timekeeping: Another fix to the VSYSCALL_OLD update_vsyscallJohn Stultz
Benjamin Herrenschmidt pointed out that I further missed modifying update_vsyscall after the wall_to_mono value was changed to a timespec64. This causes issues on powerpc32, which expects a 32bit timespec. This patch fixes the problem by properly converting from a timespec64 to a timespec before passing the value on to the arch-specific vsyscall logic. [ Thomas is currently on vacation, but reviewed it and wanted me to send this fix on to you directly. ] Cc: LKML <linux-kernel@vger.kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Reported-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: John Stultz <john.stultz@linaro.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-14Merge branch 'next' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc Pull more powerpc updates from Ben Herrenschmidt: "Here are some more powerpc bits for 3.17, essentially fixes. The biggest series, also aimed at -stable, is from Aneesh and is the result of weeks and weeks of debugging to find out why the heck or THP implementation was occasionally triggering multi-hit errors in our level 1 TLB. It ended up being a combination of issues including subtleties as to how we should invalidate those special 'MPSS' pages we use to allow the use of 16M pages inside 4K/64K "base page size" segments (you really have to love our MMU !) Another interesting one in the "OMG" category is the series from Michael adding memory barriers to spin_is_locked(). That's also the result of many days of debugging to figure out why the semaphore code would occasionally crash in ways that made no sense. It ended up being some creative lock stacking that was defeated by the fact that our locks allow a load inside the locked section to be re-ordered with the load of the lock value itself (I'm still of two mind about whether to kill that once and for all by putting a heavier barrier back into our lock implementation...). The fixes come with a long explanation in the cset comments, feel free to read it if you feel like having a headache today" * 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc: (25 commits) powerpc/thp: Add tracepoints to track hugepage invalidate powerpc/mm: Use read barrier when creating real_pte powerpc/thp: Use ACCESS_ONCE when loading pmdp powerpc/thp: Invalidate with vpn in loop powerpc/thp: Handle combo pages in invalidate powerpc/thp: Invalidate old 64K based hash page mapping before insert of 4k pte powerpc/thp: Don't recompute vsid and ssize in loop on invalidate powerpc/thp: Add write barrier after updating the valid bit powerpc: reorder per-cpu NUMA information's initialization powerpc/perf/hv-24x7: Use kmem_cache_free powerpc/pseries/hvcserver: Fix endian issue in hvcs_get_partner_info powerpc: Hard disable interrupts in xmon powerpc: remove duplicate definition of TEXASR_FS powerpc/pseries: Avoid deadlock on removing ddw powerpc/pseries: Failure on removing device node powerpc/boot: Use correct zlib types for comparison powerpc/powernv: Interface to register/unregister opal dump region printk: Add function to return log buffer address and size powerpc: Add POWER8 features to CPU_FTRS_POSSIBLE/ALWAYS powerpc/ppc476: Disable BTAC ...
2014-08-14Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security Pull seccomp fix from James Morris. BUG(!spin_is_locked()) really doesn't work very well in UP configurations without any actual spinlock state. Which is very much why we have that "assert_spin_lock()" function for this. * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: seccomp: Replace BUG(!spin_is_locked()) with assert_spin_lock
2014-08-13printk: Add function to return log buffer address and sizeVasant Hegde
Platforms like IBM Power Systems supports service processor assisted dump. It provides interface to add memory region to be captured when system is crashed. During initialization/running we can add kernel memory region to be collected. Presently we don't have a way to get the log buffer base address and size. This patch adds support to return log buffer address and size. Signed-off-by: Vasant Hegde <hegdevasant@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Acked-by: Andrew Morton <akpm@linux-foundation.org>
2014-08-11Merge branches 'pm-sleep', 'pm-cpufreq' and 'pm-cpuidle'Rafael J. Wysocki
* pm-sleep: PM / hibernate: avoid unsafe pages in e820 reserved regions * pm-cpufreq: cpufreq: arm_big_little: fix module license spec cpufreq: speedstep-smi: fix decimal printf specifiers cpufreq: OPP: Avoid sleeping while atomic cpufreq: cpu0: Do not print error message when deferring cpufreq: integrator: Use set_cpus_allowed_ptr * pm-cpuidle: cpuidle: menu: Lookup CPU runqueues less cpuidle: menu: Call nr_iowait_cpu less times cpuidle: menu: Use ktime_to_us instead of reinventing the wheel cpuidle: menu: Use shifts when calculating averages where possible
2014-08-11seccomp: Replace BUG(!spin_is_locked()) with assert_spin_lockGuenter Roeck
Current upstream kernel hangs with mips and powerpc targets in uniprocessor mode if SECCOMP is configured. Bisect points to commit dbd952127d11 ("seccomp: introduce writer locking"). Turns out that code such as BUG_ON(!spin_is_locked(&list_lock)); can not be used in uniprocessor mode because spin_is_locked() always returns false in this configuration, and that assert_spin_locked() exists for that very purpose and must be used instead. Fixes: dbd952127d11 ("seccomp: introduce writer locking") Cc: Kees Cook <keescook@chromium.org> Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Kees Cook <keescook@chromium.org>
2014-08-11Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull vfs updates from Al Viro: "Stuff in here: - acct.c fixes and general rework of mnt_pin mechanism. That allows to go for delayed-mntput stuff, which will permit mntput() on deep stack without worrying about stack overflows - fs shutdown will happen on shallow stack. IOW, we can do Eric's umount-on-rmdir series without introducing tons of stack overflows on new mntput() call chains it introduces. - Bruce's d_splice_alias() patches - more Miklos' rename() stuff. - a couple of regression fixes (stable fodder, in the end of branch) and a fix for API idiocy in iov_iter.c. There definitely will be another pile, maybe even two. I'd like to get Eric's series in this time, but even if we miss it, it'll go right in the beginning of for-next in the next cycle - the tricky part of prereqs is in this pile" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (40 commits) fix copy_tree() regression __generic_file_write_iter(): fix handling of sync error after DIO switch iov_iter_get_pages() to passing maximal number of pages fs: mark __d_obtain_alias static dcache: d_splice_alias should detect loops exportfs: update Exporting documentation dcache: d_find_alias needn't recheck IS_ROOT && DCACHE_DISCONNECTED dcache: remove unused d_find_alias parameter dcache: d_obtain_alias callers don't all want DISCONNECTED dcache: d_splice_alias should ignore DCACHE_DISCONNECTED dcache: d_splice_alias mustn't create directory aliases dcache: close d_move race in d_splice_alias dcache: move d_splice_alias namei: trivial fix to vfs_rename_dir comment VFS: allow ->d_manage() to declare -EISDIR in rcu_walk mode. cifs: support RENAME_NOREPLACE hostfs: support rename flags shmem: support RENAME_EXCHANGE shmem: support RENAME_NOREPLACE btrfs: add RENAME_NOREPLACE ...
2014-08-11Merge tag 'modules-next-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux Pull module updates from Rusty Russell: "This finally applies the stricter sysfs perms checking we pulled out before last merge window. A few stragglers are fixed (thanks linux-next!)" * tag 'modules-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux: arch/powerpc/platforms/powernv/opal-dump.c: fix world-writable sysfs files arch/powerpc/platforms/powernv/opal-elog.c: fix world-writable sysfs files drivers/video/fbdev/s3c2410fb.c: don't make debug world-writable. ARM: avoid ARM binutils leaking ELF local symbols scripts: modpost: Remove numeric suffix pattern matching scripts: modpost: fix compilation warning sysfs: disallow world-writable files. module: return bool from within_module*() module: add within_module() function modules: Fix build error in moduleloader.h
2014-08-10Merge tag 'trace-fixes-3.16' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull trace file read iterator fixes from Steven Rostedt: "This contains a fix for two long standing bugs. Both of which are rarely ever hit, and requires the user to do something that users rarely do. It took a few special test cases to even trigger this bug, and one of them was just one test in the process of finishing up as another one started. Both bugs have to do with the ring buffer iterator rb_iter_peek(), but one is more indirect than the other. The fist bug fix is simply an increase in the safety net loop counter. The counter makes sure that the rb_iter_peek() only iterates the number of times we expect it can, and no more. Well, there was one way it could iterate one more than we expected, and that caused the ring buffer to shutdown with a nasty warning. The fix was simply to up that counter by one. The other bug has to be with rb_iter_reset() (called by rb_iter_peek()). This happens when a user reads both the trace_pipe and trace files. The trace_pipe is a consuming read and does not use the ring buffer iterator, but the trace file is not a consuming read and does use the ring buffer iterator. When the trace file is being read, if it detects that a consuming read occurred, it resets the iterator and starts over. But the reset code that does this (rb_iter_reset()), checks if the reader_page is linked to the ring buffer or not, and will look into the ring buffer itself if it is not. This is wrong, as it should always try to read the reader page first. Not to mention, the code that looked into the ring buffer did it wrong, and used the header_page "read" offset to start reading on that page. That offset is bogus for pages in the writable ring buffer, and was corrupting the iterator, and it would start returning bogus events" * tag 'trace-fixes-3.16' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: ring-buffer: Always reset iterator to reader page ring-buffer: Up rb_iter_peek() loop count to 3
2014-08-10Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace Pull namespace updates from Eric Biederman: "This is a bunch of small changes built against 3.16-rc6. The most significant change for users is the first patch which makes setns drmatically faster by removing unneded rcu handling. The next chunk of changes are so that "mount -o remount,.." will not allow the user namespace root to drop flags on a mount set by the system wide root. Aks this forces read-only mounts to stay read-only, no-dev mounts to stay no-dev, no-suid mounts to stay no-suid, no-exec mounts to stay no exec and it prevents unprivileged users from messing with a mounts atime settings. I have included my test case as the last patch in this series so people performing backports can verify this change works correctly. The next change fixes a bug in NFS that was discovered while auditing nsproxy users for the first optimization. Today you can oops the kernel by reading /proc/fs/nfsfs/{servers,volumes} if you are clever with pid namespaces. I rebased and fixed the build of the !CONFIG_NFS_FS case yesterday when a build bot caught my typo. Given that no one to my knowledge bases anything on my tree fixing the typo in place seems more responsible that requiring a typo-fix to be backported as well. The last change is a small semantic cleanup introducing /proc/thread-self and pointing /proc/mounts and /proc/net at it. This prevents several kinds of problemantic corner cases. It is a user-visible change so it has a minute chance of causing regressions so the change to /proc/mounts and /proc/net are individual one line commits that can be trivially reverted. Unfortunately I lost and could not find the email of the original reporter so he is not credited. From at least one perspective this change to /proc/net is a refgression fix to allow pthread /proc/net uses that were broken by the introduction of the network namespace" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: proc: Point /proc/mounts at /proc/thread-self/mounts instead of /proc/self/mounts proc: Point /proc/net at /proc/thread-self/net instead of /proc/self/net proc: Implement /proc/thread-self to point at the directory of the current thread proc: Have net show up under /proc/<tgid>/task/<tid> NFS: Fix /proc/fs/nfsfs/servers and /proc/fs/nfsfs/volumes mnt: Add tests for unprivileged remount cases that have found to be faulty mnt: Change the default remount atime from relatime to the existing value mnt: Correct permission checks in do_remount mnt: Move the test for MNT_LOCK_READONLY from change_mount_flags into do_remount mnt: Only change user settable mount flags in remount namespaces: Use task_lock and not rcu to protect nsproxy
2014-08-09Merge branch 'signal-cleanup' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rw/misc Pull arch signal handling cleanup from Richard Weinberger: "This patch series moves all remaining archs to the get_signal(), signal_setup_done() and sigsp() functions. Currently these archs use open coded variants of the said functions. Further, unused parameters get removed from get_signal_to_deliver(), tracehook_signal_handler() and signal_delivered(). At the end of the day we save around 500 lines of code." * 'signal-cleanup' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/misc: (43 commits) powerpc: Use sigsp() openrisc: Use sigsp() mn10300: Use sigsp() mips: Use sigsp() microblaze: Use sigsp() metag: Use sigsp() m68k: Use sigsp() m32r: Use sigsp() hexagon: Use sigsp() frv: Use sigsp() cris: Use sigsp() c6x: Use sigsp() blackfin: Use sigsp() avr32: Use sigsp() arm64: Use sigsp() arc: Use sigsp() sas_ss_flags: Remove nested ternary if Rip out get_signal_to_deliver() Clean up signal_delivered() tracehook_signal_handler: Remove sig, info, ka and regs ...
2014-08-08kexec: verify the signature of signed PE bzImageVivek Goyal
This is the final piece of the puzzle of verifying kernel image signature during kexec_file_load() syscall. This patch calls into PE file routines to verify signature of bzImage. If signature are valid, kexec_file_load() succeeds otherwise it fails. Two new config options have been introduced. First one is CONFIG_KEXEC_VERIFY_SIG. This option enforces that kernel has to be validly signed otherwise kernel load will fail. If this option is not set, no signature verification will be done. Only exception will be when secureboot is enabled. In that case signature verification should be automatically enforced when secureboot is enabled. But that will happen when secureboot patches are merged. Second config option is CONFIG_KEXEC_BZIMAGE_VERIFY_SIG. This option enables signature verification support on bzImage. If this option is not set and previous one is set, kernel image loading will fail because kernel does not have support to verify signature of bzImage. I tested these patches with both "pesign" and "sbsign" signed bzImages. I used signing_key.priv key and signing_key.x509 cert for signing as generated during kernel build process (if module signing is enabled). Used following method to sign bzImage. pesign ====== - Convert DER format cert to PEM format cert openssl x509 -in signing_key.x509 -inform DER -out signing_key.x509.PEM -outform PEM - Generate a .p12 file from existing cert and private key file openssl pkcs12 -export -out kernel-key.p12 -inkey signing_key.priv -in signing_key.x509.PEM - Import .p12 file into pesign db pk12util -i /tmp/kernel-key.p12 -d /etc/pki/pesign - Sign bzImage pesign -i /boot/vmlinuz-3.16.0-rc3+ -o /boot/vmlinuz-3.16.0-rc3+.signed.pesign -c "Glacier signing key - Magrathea" -s sbsign ====== sbsign --key signing_key.priv --cert signing_key.x509.PEM --output /boot/vmlinuz-3.16.0-rc3+.signed.sbsign /boot/vmlinuz-3.16.0-rc3+ Patch details: Well all the hard work is done in previous patches. Now bzImage loader has just call into that code and verify whether bzImage signature are valid or not. Also create two config options. First one is CONFIG_KEXEC_VERIFY_SIG. This option enforces that kernel has to be validly signed otherwise kernel load will fail. If this option is not set, no signature verification will be done. Only exception will be when secureboot is enabled. In that case signature verification should be automatically enforced when secureboot is enabled. But that will happen when secureboot patches are merged. Second config option is CONFIG_KEXEC_BZIMAGE_VERIFY_SIG. This option enables signature verification support on bzImage. If this option is not set and previous one is set, kernel image loading will fail because kernel does not have support to verify signature of bzImage. Signed-off-by: Vivek Goyal <vgoyal@redhat.com> Cc: Borislav Petkov <bp@suse.de> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Yinghai Lu <yinghai@kernel.org> Cc: Eric Biederman <ebiederm@xmission.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Matthew Garrett <mjg59@srcf.ucam.org> Cc: Greg Kroah-Hartman <greg@kroah.com> Cc: Dave Young <dyoung@redhat.com> Cc: WANG Chao <chaowang@redhat.com> Cc: Baoquan He <bhe@redhat.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Matt Fleming <matt@console-pimps.org> Cc: David Howells <dhowells@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-08kexec: support for kexec on panic using new system callVivek Goyal
This patch adds support for loading a kexec on panic (kdump) kernel usning new system call. It prepares ELF headers for memory areas to be dumped and for saved cpu registers. Also prepares the memory map for second kernel and limits its boot to reserved areas only. Signed-off-by: Vivek Goyal <vgoyal@redhat.com> Cc: Borislav Petkov <bp@suse.de> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Yinghai Lu <yinghai@kernel.org> Cc: Eric Biederman <ebiederm@xmission.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Matthew Garrett <mjg59@srcf.ucam.org> Cc: Greg Kroah-Hartman <greg@kroah.com> Cc: Dave Young <dyoung@redhat.com> Cc: WANG Chao <chaowang@redhat.com> Cc: Baoquan He <bhe@redhat.com> Cc: Andy Lutomirski <luto@amacapital.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-08kexec-bzImage64: support for loading bzImage using 64bit entryVivek Goyal
This is loader specific code which can load bzImage and set it up for 64bit entry. This does not take care of 32bit entry or real mode entry. 32bit mode entry can be implemented if somebody needs it. Signed-off-by: Vivek Goyal <vgoyal@redhat.com> Cc: Borislav Petkov <bp@suse.de> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Yinghai Lu <yinghai@kernel.org> Cc: Eric Biederman <ebiederm@xmission.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Matthew Garrett <mjg59@srcf.ucam.org> Cc: Greg Kroah-Hartman <greg@kroah.com> Cc: Dave Young <dyoung@redhat.com> Cc: WANG Chao <chaowang@redhat.com> Cc: Baoquan He <bhe@redhat.com> Cc: Andy Lutomirski <luto@amacapital.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-08kexec: load and relocate purgatory at kernel load timeVivek Goyal
Load purgatory code in RAM and relocate it based on the location. Relocation code has been inspired by module relocation code and purgatory relocation code in kexec-tools. Also compute the checksums of loaded kexec segments and store them in purgatory. Arch independent code provides this functionality so that arch dependent bootloaders can make use of it. Helper functions are provided to get/set symbol values in purgatory which are used by bootloaders later to set things like stack and entry point of second kernel etc. Signed-off-by: Vivek Goyal <vgoyal@redhat.com> Cc: Borislav Petkov <bp@suse.de> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Yinghai Lu <yinghai@kernel.org> Cc: Eric Biederman <ebiederm@xmission.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Matthew Garrett <mjg59@srcf.ucam.org> Cc: Greg Kroah-Hartman <greg@kroah.com> Cc: Dave Young <dyoung@redhat.com> Cc: WANG Chao <chaowang@redhat.com> Cc: Baoquan He <bhe@redhat.com> Cc: Andy Lutomirski <luto@amacapital.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-08kexec: implementation of new syscall kexec_file_loadVivek Goyal
Previous patch provided the interface definition and this patch prvides implementation of new syscall. Previously segment list was prepared in user space. Now user space just passes kernel fd, initrd fd and command line and kernel will create a segment list internally. This patch contains generic part of the code. Actual segment preparation and loading is done by arch and image specific loader. Which comes in next patch. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Vivek Goyal <vgoyal@redhat.com> Cc: Borislav Petkov <bp@suse.de> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Yinghai Lu <yinghai@kernel.org> Cc: Eric Biederman <ebiederm@xmission.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Matthew Garrett <mjg59@srcf.ucam.org> Cc: Greg Kroah-Hartman <greg@kroah.com> Cc: Dave Young <dyoung@redhat.com> Cc: WANG Chao <chaowang@redhat.com> Cc: Baoquan He <bhe@redhat.com> Cc: Andy Lutomirski <luto@amacapital.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-08kexec: new syscall kexec_file_load() declarationVivek Goyal
This is the new syscall kexec_file_load() declaration/interface. I have reserved the syscall number only for x86_64 so far. Other architectures (including i386) can reserve syscall number when they enable the support for this new syscall. Signed-off-by: Vivek Goyal <vgoyal@redhat.com> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Borislav Petkov <bp@suse.de> Cc: Yinghai Lu <yinghai@kernel.org> Cc: Eric Biederman <ebiederm@xmission.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Matthew Garrett <mjg59@srcf.ucam.org> Cc: Greg Kroah-Hartman <greg@kroah.com> Cc: Dave Young <dyoung@redhat.com> Cc: WANG Chao <chaowang@redhat.com> Cc: Baoquan He <bhe@redhat.com> Cc: Andy Lutomirski <luto@amacapital.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-08resource: provide new functions to walk through resourcesVivek Goyal
I have added two more functions to walk through resources. Currently walk_system_ram_range() deals with pfn and /proc/iomem can contain partial pages. By dealing in pfn, callback function loses the info that last page of a memory range is a partial page and not the full page. So I implemented walk_system_ram_res() which returns u64 values to callback functions and now it properly return start and end address. walk_system_ram_range() uses find_next_system_ram() to find the next ram resource. This in turn only travels through siblings of top level child and does not travers through all the nodes of the resoruce tree. I also need another function where I can walk through all the resources, for example figure out where "GART" aperture is. Figure out where ACPI memory is. So I wrote another function walk_iomem_res() which walks through all /proc/iomem resources and returns matches as asked by caller. Caller can specify "name" of resource, start and end and flags. Got rid of find_next_system_ram_res() and instead implemented more generic find_next_iomem_res() which can be used to traverse top level children only based on an argument. Signed-off-by: Vivek Goyal <vgoyal@redhat.com> Cc: Yinghai Lu <yinghai@kernel.org> Cc: Borislav Petkov <bp@suse.de> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Eric Biederman <ebiederm@xmission.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Matthew Garrett <mjg59@srcf.ucam.org> Cc: Greg Kroah-Hartman <greg@kroah.com> Cc: Dave Young <dyoung@redhat.com> Cc: WANG Chao <chaowang@redhat.com> Cc: Baoquan He <bhe@redhat.com> Cc: Andy Lutomirski <luto@amacapital.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-08kexec: use common function for kimage_normal_alloc() and kimage_crash_alloc()Vivek Goyal
kimage_normal_alloc() and kimage_crash_alloc() are doing lot of similar things and differ only little. So instead of having two separate functions create a common function kimage_alloc_init() and pass it the "flags" argument which tells whether it is normal kexec or kexec_on_panic. And this function should be able to deal with both the cases. This consolidation also helps later where we can use a common function kimage_file_alloc_init() to handle normal and crash cases for new file based kexec syscall. Signed-off-by: Vivek Goyal <vgoyal@redhat.com> Cc: Borislav Petkov <bp@suse.de> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Yinghai Lu <yinghai@kernel.org> Cc: Eric Biederman <ebiederm@xmission.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Matthew Garrett <mjg59@srcf.ucam.org> Cc: Greg Kroah-Hartman <greg@kroah.com> Cc: Dave Young <dyoung@redhat.com> Cc: WANG Chao <chaowang@redhat.com> Cc: Baoquan He <bhe@redhat.com> Cc: Andy Lutomirski <luto@amacapital.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-08kexec: move segment verification code in a separate functionVivek Goyal
Previously do_kimage_alloc() will allocate a kimage structure, copy segment list from user space and then do the segment list sanity verification. Break down this function in 3 parts. do_kimage_alloc_init() to do actual allocation and basic initialization of kimage structure. copy_user_segment_list() to copy segment list from user space and sanity_check_segment_list() to verify the sanity of segment list as passed by user space. In later patches, I need to only allocate kimage and not copy segment list from user space. So breaking down in smaller functions enables re-use of code at other places. Signed-off-by: Vivek Goyal <vgoyal@redhat.com> Cc: Borislav Petkov <bp@suse.de> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Yinghai Lu <yinghai@kernel.org> Cc: Eric Biederman <ebiederm@xmission.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Matthew Garrett <mjg59@srcf.ucam.org> Cc: Greg Kroah-Hartman <greg@kroah.com> Cc: Dave Young <dyoung@redhat.com> Cc: WANG Chao <chaowang@redhat.com> Cc: Baoquan He <bhe@redhat.com> Cc: Andy Lutomirski <luto@amacapital.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-08kexec: rename unusebale_pages to unusable_pagesVivek Goyal
Let's use the more common "unusable". This patch was originally written and posted by Boris. I am including it in this patch series. Signed-off-by: Borislav Petkov <bp@suse.de> Signed-off-by: Vivek Goyal <vgoyal@redhat.com> Cc: Borislav Petkov <bp@suse.de> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Yinghai Lu <yinghai@kernel.org> Cc: Eric Biederman <ebiederm@xmission.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Matthew Garrett <mjg59@srcf.ucam.org> Cc: Greg Kroah-Hartman <greg@kroah.com> Cc: Dave Young <dyoung@redhat.com> Cc: WANG Chao <chaowang@redhat.com> Cc: Baoquan He <bhe@redhat.com> Cc: Andy Lutomirski <luto@amacapital.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-08bin2c: move bin2c in scripts/basicVivek Goyal
This patch series does not do kernel signature verification yet. I plan to post another patch series for that. Now distributions are already signing PE/COFF bzImage with PKCS7 signature I plan to parse and verify those signatures. Primary goal of this patchset is to prepare groundwork so that kernel image can be signed and signatures be verified during kexec load. This should help with two things. - It should allow kexec/kdump on secureboot enabled machines. - In general it can help even without secureboot. By being able to verify kernel image signature in kexec, it should help with avoiding module signing restrictions. Matthew Garret showed how to boot into a custom kernel, modify first kernel's memory and then jump back to old kernel and bypass any policy one wants to. This patch (of 15): Kexec wants to use bin2c and it wants to use it really early in the build process. See arch/x86/purgatory/ code in later patches. So move bin2c in scripts/basic so that it can be built very early and be usable by arch/x86/purgatory/ Signed-off-by: Vivek Goyal <vgoyal@redhat.com> Cc: Borislav Petkov <bp@suse.de> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Yinghai Lu <yinghai@kernel.org> Cc: Eric Biederman <ebiederm@xmission.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Matthew Garrett <mjg59@srcf.ucam.org> Cc: Greg Kroah-Hartman <greg@kroah.com> Cc: Dave Young <dyoung@redhat.com> Cc: WANG Chao <chaowang@redhat.com> Cc: Baoquan He <bhe@redhat.com> Cc: Andy Lutomirski <luto@amacapital.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-08shm: add memfd_create() syscallDavid Herrmann
memfd_create() is similar to mmap(MAP_ANON), but returns a file-descriptor that you can pass to mmap(). It can support sealing and avoids any connection to user-visible mount-points. Thus, it's not subject to quotas on mounted file-systems, but can be used like malloc()'ed memory, but with a file-descriptor to it. memfd_create() returns the raw shmem file, so calls like ftruncate() can be used to modify the underlying inode. Also calls like fstat() will return proper information and mark the file as regular file. If you want sealing, you can specify MFD_ALLOW_SEALING. Otherwise, sealing is not supported (like on all other regular files). Compared to O_TMPFILE, it does not require a tmpfs mount-point and is not subject to a filesystem size limit. It is still properly accounted to memcg limits, though, and to the same overcommit or no-overcommit accounting as all user memory. Signed-off-by: David Herrmann <dh.herrmann@gmail.com> Acked-by: Hugh Dickins <hughd@google.com> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Ryan Lortie <desrt@desrt.ca> Cc: Lennart Poettering <lennart@poettering.net> Cc: Daniel Mack <zonque@gmail.com> Cc: Andy Lutomirski <luto@amacapital.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-08mm: allow drivers to prevent new writable mappingsDavid Herrmann
This patch (of 6): The i_mmap_writable field counts existing writable mappings of an address_space. To allow drivers to prevent new writable mappings, make this counter signed and prevent new writable mappings if it is negative. This is modelled after i_writecount and DENYWRITE. This will be required by the shmem-sealing infrastructure to prevent any new writable mappings after the WRITE seal has been set. In case there exists a writable mapping, this operation will fail with EBUSY. Note that we rely on the fact that iff you already own a writable mapping, you can increase the counter without using the helpers. This is the same that we do for i_writecount. Signed-off-by: David Herrmann <dh.herrmann@gmail.com> Acked-by: Hugh Dickins <hughd@google.com> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Ryan Lortie <desrt@desrt.ca> Cc: Lennart Poettering <lennart@poettering.net> Cc: Daniel Mack <zonque@gmail.com> Cc: Andy Lutomirski <luto@amacapital.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-08kernel/acct.c: fix coding style warnings and errorsIonut Alexa
Signed-off-by: Ionut Alexa <ionut.m.alexa@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-08shm: make exit_shm work proportional to task activityJack Miller
This is small set of patches our team has had kicking around for a few versions internally that fixes tasks getting hung on shm_exit when there are many threads hammering it at once. Anton wrote a simple test to cause the issue: http://ozlabs.org/~anton/junkcode/bust_shm_exit.c Before applying this patchset, this test code will cause either hanging tracebacks or pthread out of memory errors. After this patchset, it will still produce output like: root@somehost:~# ./bust_shm_exit 1024 160 ... INFO: rcu_sched detected stalls on CPUs/tasks: {} (detected by 116, t=2111 jiffies, g=241, c=240, q=7113) INFO: Stall ended before state dump start ... But the task will continue to run along happily, so we consider this an improvement over hanging, even if it's a bit noisy. This patch (of 3): exit_shm obtains the ipc_ns shm rwsem for write and holds it while it walks every shared memory segment in the namespace. Thus the amount of work is related to the number of shm segments in the namespace not the number of segments that might need to be cleaned. In addition, this occurs after the task has been notified the thread has exited, so the number of tasks waiting for the ns shm rwsem can grow without bound until memory is exausted. Add a list to the task struct of all shmids allocated by this task. Init the list head in copy_process. Use the ns->rwsem for locking. Add segments after id is added, remove before removing from id. On unshare of NEW_IPCNS orphan any ids as if the task had exited, similar to handling of semaphore undo. I chose a define for the init sequence since its a simple list init, otherwise it would require a function call to avoid include loops between the semaphore code and the task struct. Converting the list_del to list_del_init for the unshare cases would remove the exit followed by init, but I left it blow up if not inited. Signed-off-by: Milton Miller <miltonm@bga.com> Signed-off-by: Jack Miller <millerjo@us.ibm.com> Cc: Davidlohr Bueso <davidlohr@hp.com> Cc: Manfred Spraul <manfred@colorfullife.com> Cc: Anton Blanchard <anton@samba.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-08panic: add TAINT_SOFTLOCKUPJosh Hunt
This taint flag will be set if the system has ever entered a softlockup state. Similar to TAINT_WARN it is useful to know whether or not the system has been in a softlockup state when debugging. [akpm@linux-foundation.org: apply the taint before calling panic()] Signed-off-by: Josh Hunt <johunt@akamai.com> Cc: Jason Baron <jbaron@akamai.com> Cc: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-08kernel/gcov/fs.c: remove unnecessary null test before debugfs_removeFabian Frederick
This fixes checkpatch warning: WARNING: debugfs_remove(NULL) is safe this check is probably not required Signed-off-by: Fabian Frederick <fabf@skynet.be> Cc: Peter Oberparleiter <oberpar@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-08kernel/fork.c: make mm_init_owner staticVladimir Davydov
It's only used in fork.c:mm_init(). Signed-off-by: Vladimir Davydov <vdavydov@parallels.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-08fork: copy mm's vm usage counters under mmap_semVladimir Davydov
If a forking process has a thread calling (un)mmap (silly but still), the child process may have some of its mm's vm usage counters (total_vm and friends) screwed up, because currently they are copied from oldmm w/o holding any locks (memcpy in dup_mm). This patch moves the counters initialization to dup_mmap() to be called under oldmm->mmap_sem, which eliminates any possibility of race. Signed-off-by: Vladimir Davydov <vdavydov@parallels.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: Christoph Lameter <cl@linux.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-08fork: reset mm->pinned_vmVladimir Davydov
mm->pinned_vm counts pages of mm's address space that were permanently pinned in memory by increasing their reference counter. The counter was introduced by commit bc3e53f682d9 ("mm: distinguish between mlocked and pinned pages"), while before it locked_vm had been used for such pages. Obviously, we should reset the counter on fork if !CLONE_VM, just like we do with locked_vm, but currently we don't. Let's fix it. This patch will fix the contents of /proc/pid/status:VmPin. ib_umem_get[infiniband] and perf_mmap still check pinned_vm against RLIMIT_MEMLOCK. It's left from the times when pinned pages were accounted under locked_vm, but today it looks wrong. It isn't clear how we should deal with it. We still have some drivers accounting pinned pages under mm->locked_vm - this is what commit bc3e53f682d9 was fighting against. It's infiniband/usnic and vfio. Signed-off-by: Vladimir Davydov <vdavydov@parallels.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: Christoph Lameter <cl@linux.com> Cc: Roland Dreier <roland@kernel.org> Cc: Sean Hefty <sean.hefty@intel.com> Cc: Hal Rosenstock <hal.rosenstock@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-08fork/exec: cleanup mm initializationVladimir Davydov
mm initialization on fork/exec is spread all over the place, which makes the code look inconsistent. We have mm_init(), which is supposed to init/nullify mm's internals, but it doesn't init all the fields it should: - on fork ->mmap,mm_rb,vmacache_seqnum,map_count,mm_cpumask,locked_vm are zeroed in dup_mmap(); - on fork ->pmd_huge_pte is zeroed in dup_mm(), immediately before calling mm_init(); - ->cpu_vm_mask_var ptr is initialized by mm_init_cpumask(), which is called before mm_init() on both fork and exec; - ->context is initialized by init_new_context(), which is called after mm_init() on both fork and exec; Let's consolidate all the initializations in mm_init() to make the code look cleaner. Signed-off-by: Vladimir Davydov <vdavydov@parallels.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: Christoph Lameter <cl@linux.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-08proc: constify seq_operationsFabian Frederick
proc_uid_seq_operations, proc_gid_seq_operations and proc_projid_seq_operations are only called in proc_id_map_open with seq_open as const struct seq_operations so we can constify the 3 structures and update proc_id_map_open prototype. text data bss dec hex filename 6817 404 1984 9205 23f5 kernel/user_namespace.o-before 6913 308 1984 9205 23f5 kernel/user_namespace.o-after Signed-off-by: Fabian Frederick <fabf@skynet.be> Cc: Joe Perches <joe@perches.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-08kernel/exit.c: fix coding style warnings and errorsIonut Alexa
Fixed coding style warnings and errors. Signed-off-by: Ionut Alexa <ionut.m.alexa@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-08kernel/test_kprobes.c: use current logging functionsFabian Frederick
- Add pr_fmt - Coalesce formats - Use current pr_foo() functions instead of printk - Remove unnecessary "failed" display (already in log level). Signed-off-by: Fabian Frederick <fabf@skynet.be> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-08kernel/kallsyms.c: fix %pB when there's no symbol at the addressNamhyung Kim
__sprint_symbol() should restore original address when kallsyms_lookup() failed to find a symbol. It's reported when dumpstack shows an address in a dynamically allocated trampoline for ftrace. [ 1314.612287] [<ffffffff81700312>] dump_stack+0x45/0x56 [ 1314.612290] [<ffffffff8125f5b0>] ? meminfo_proc_open+0x30/0x30 [ 1314.612293] [<ffffffffa080a494>] kpatch_ftrace_handler+0x14/0xf0 [kpatch] [ 1314.612306] [<ffffffffa00160c4>] 0xffffffffa00160c3 You can see a difference in the hex address - c4 and c3. Fix it. Signed-off-by: Namhyung Kim <namhyung@kernel.org> Reported-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-08page-cgroup: get rid of NR_PCG_FLAGSVladimir Davydov
It's not used anywhere today, so let's remove it. Signed-off-by: Vladimir Davydov <vdavydov@parallels.com> Acked-by: Michal Hocko <mhocko@suse.cz> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-08mm: memcontrol: use page lists for uncharge batchingJohannes Weiner
Pages are now uncharged at release time, and all sources of batched uncharges operate on lists of pages. Directly use those lists, and get rid of the per-task batching state. This also batches statistics accounting, in addition to the res counter charges, to reduce IRQ-disabling and re-enabling. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Michal Hocko <mhocko@suse.cz> Cc: Hugh Dickins <hughd@google.com> Cc: Tejun Heo <tj@kernel.org> Cc: Vladimir Davydov <vdavydov@parallels.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Vladimir Davydov <vdavydov@parallels.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-08mm: memcontrol: rewrite charge APIJohannes Weiner
These patches rework memcg charge lifetime to integrate more naturally with the lifetime of user pages. This drastically simplifies the code and reduces charging and uncharging overhead. The most expensive part of charging and uncharging is the page_cgroup bit spinlock, which is removed entirely after this series. Here are the top-10 profile entries of a stress test that reads a 128G sparse file on a freshly booted box, without even a dedicated cgroup (i.e. executing in the root memcg). Before: 15.36% cat [kernel.kallsyms] [k] copy_user_generic_string 13.31% cat [kernel.kallsyms] [k] memset 11.48% cat [kernel.kallsyms] [k] do_mpage_readpage 4.23% cat [kernel.kallsyms] [k] get_page_from_freelist 2.38% cat [kernel.kallsyms] [k] put_page 2.32% cat [kernel.kallsyms] [k] __mem_cgroup_commit_charge 2.18% kswapd0 [kernel.kallsyms] [k] __mem_cgroup_uncharge_common 1.92% kswapd0 [kernel.kallsyms] [k] shrink_page_list 1.86% cat [kernel.kallsyms] [k] __radix_tree_lookup 1.62% cat [kernel.kallsyms] [k] __pagevec_lru_add_fn After: 15.67% cat [kernel.kallsyms] [k] copy_user_generic_string 13.48% cat [kernel.kallsyms] [k] memset 11.42% cat [kernel.kallsyms] [k] do_mpage_readpage 3.98% cat [kernel.kallsyms] [k] get_page_from_freelist 2.46% cat [kernel.kallsyms] [k] put_page 2.13% kswapd0 [kernel.kallsyms] [k] shrink_page_list 1.88% cat [kernel.kallsyms] [k] __radix_tree_lookup 1.67% cat [kernel.kallsyms] [k] __pagevec_lru_add_fn 1.39% kswapd0 [kernel.kallsyms] [k] free_pcppages_bulk 1.30% cat [kernel.kallsyms] [k] kfree As you can see, the memcg footprint has shrunk quite a bit. text data bss dec hex filename 37970 9892 400 48262 bc86 mm/memcontrol.o.old 35239 9892 400 45531 b1db mm/memcontrol.o This patch (of 4): The memcg charge API charges pages before they are rmapped - i.e. have an actual "type" - and so every callsite needs its own set of charge and uncharge functions to know what type is being operated on. Worse, uncharge has to happen from a context that is still type-specific, rather than at the end of the page's lifetime with exclusive access, and so requires a lot of synchronization. Rewrite the charge API to provide a generic set of try_charge(), commit_charge() and cancel_charge() transaction operations, much like what's currently done for swap-in: mem_cgroup_try_charge() attempts to reserve a charge, reclaiming pages from the memcg if necessary. mem_cgroup_commit_charge() commits the page to the charge once it has a valid page->mapping and PageAnon() reliably tells the type. mem_cgroup_cancel_charge() aborts the transaction. This reduces the charge API and enables subsequent patches to drastically simplify uncharging. As pages need to be committed after rmap is established but before they are added to the LRU, page_add_new_anon_rmap() must stop doing LRU additions again. Revive lru_cache_add_active_or_unevictable(). [hughd@google.com: fix shmem_unuse] [hughd@google.com: Add comments on the private use of -EAGAIN] Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Michal Hocko <mhocko@suse.cz> Cc: Tejun Heo <tj@kernel.org> Cc: Vladimir Davydov <vdavydov@parallels.com> Signed-off-by: Hugh Dickins <hughd@google.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-07kernel/acct.c: fix coding style warnings and errorsIonut Alexa
Signed-off-by: Ionut Alexa <ionut.m.alexa@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-08-07death to mnt_pinnedAl Viro
Rather than playing silly buggers with vfsmount refcounts, just have acct_on() ask fs/namespace.c for internal clone of file->f_path.mnt and replace it with said clone. Then attach the pin to original vfsmount. Voila - the clone will be alive until the file gets closed, making sure that underlying superblock remains active, etc., and we can drop the original vfsmount, so that it's not kept busy. If the file lives until the final mntput of the original vfsmount, we'll notice that there's an fs_pin (one in bsd_acct_struct that holds that file) and mnt_pin_kill() will take it out. Since ->kill() is synchronous, we won't proceed past that point until these files are closed (and private clones of our vfsmount are gone), so we get the same ordering warranties we used to get. mnt_pin()/mnt_unpin()/->mnt_pinned is gone now, and good riddance - it never became usable outside of kernel/acct.c (and racy wrt umount even there). Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-08-07take fs_pin stuff to fs/*Al Viro
Add a new field to fs_pin - kill(pin). That's what umount and r/o remount will be calling for all pins attached to vfsmount and superblock resp. Called after bumping the refcount, so it won't go away under us. Dropping the refcount is responsibility of the instance. All generic stuff moved to fs/fs_pin.c; the next step will rip all the knowledge of kernel/acct.c from fs/super.c and fs/namespace.c. After that - death to mnt_pin(); it was intended to be usable as generic mechanism for code that wants to attach objects to vfsmount, so that they would not make the sucker busy and would get killed on umount. Never got it right; it remained acct.c-specific all along. Now it's very close to being killable. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-08-07start carving bsd_acct_struct upAl Viro
pull generic parts into struct fs_pin. Eventually we want those to replace mnt_pin()/mnt_unpin() mess; that stuff will move to fs/*. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-08-07acct: move mnt_pin() upwards.Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-08-07make acct_kill() wait for file closing.Al Viro
Do actual closing of file via schedule_work(). And use __fput_sync() there. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-08-07acct: get rid of acct_lock for acct->countAl Viro
* make acct->count atomic and acct freeing - rcu-delayed. * instead of grabbing acct_lock around the places where we take a reference, do that under rcu_read_lock() with atomic_long_inc_not_zero(). * have the new acct locked before making ns->bacct point to it Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-08-07acct: get rid of acct_listAl Viro
Put these suckers on per-vfsmount and per-superblock lists instead. Note: right now it's still acct_lock for everything, but that's going to change. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-08-07acct: simplify check_free_space()Al Viro
a) file can't be NULL b) file can't be changed under us c) all writes are serialized by acct->lock; no need to mess with spinlock there. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>