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2016-08-10rapidio: dereferencing an error pointerDan Carpenter
Original patch: https://lkml.org/lkml/2016/8/4/32 If riocm_ch_alloc() fails then we end up dereferencing the error pointer. The problem is that we're not unwinding in the reverse order from how we allocate things so it gets confusing. I've changed this around so now "ch" is NULL when we are done with it after we call riocm_put_channel(). That way we can check if it's NULL and avoid calling riocm_put_channel() on it twice. I renamed err_nodev to err_put_new_ch so that it better reflects what the goto does. Then because we had flipping things around, it means we don't neeed to initialize the pointers to NULL and we can remove an if statement and pull things in an indent level. Link: http://lkml.kernel.org/r/20160805152406.20713-1-alexandre.bounine@idt.com Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Alexandre Bounine <alexandre.bounine@idt.com> Cc: Matt Porter <mporter@kernel.crashing.org> Cc: Andre van Herk <andre.van.herk@prodrive-technologies.com> Cc: Barry Wood <barry.wood@idt.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-10tools/testing/nvdimm: fix SIGTERM vs hotplug crashDan Williams
The unit tests crash when hotplug races the previous probe. This race requires that the loading of the nfit_test module be terminated with SIGTERM, and the module to be unloaded while the ars scan is still running. In contrast to the normal nfit driver, the unit test calls acpi_nfit_init() twice to simulate hotplug, whereas the nominal case goes through the acpi_nfit_notify() event handler. The acpi_nfit_notify() path is careful to flush the previous region registration before servicing the hotplug event. The unit test was missing this guarantee. BUG: unable to handle kernel NULL pointer dereference at (null) IP: [<ffffffff810cdce7>] pwq_activate_delayed_work+0x47/0x170 [..] Call Trace: [<ffffffff810ce186>] pwq_dec_nr_in_flight+0x66/0xa0 [<ffffffff810ce490>] process_one_work+0x2d0/0x680 [<ffffffff810ce331>] ? process_one_work+0x171/0x680 [<ffffffff810ce88e>] worker_thread+0x4e/0x480 [<ffffffff810ce840>] ? process_one_work+0x680/0x680 [<ffffffff810ce840>] ? process_one_work+0x680/0x680 [<ffffffff810d5343>] kthread+0xf3/0x110 [<ffffffff8199846f>] ret_from_fork+0x1f/0x40 [<ffffffff810d5250>] ? kthread_create_on_node+0x230/0x230 Cc: <stable@vger.kernel.org> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2016-08-10arm64: Kconfig: select HISILICON_IRQ_MBIGEN only if PCI is selectedSudeep Holla
Even when PCI is disabled, ARCH_HISI selects HISILICON_IRQ_MBIGEN triggerring the following config warning: warning: (ARM64 && HISILICON_IRQ_MBIGEN) selects ARM_GIC_V3_ITS which has unmet direct dependencies (PCI && PCI_MSI) This patch makes selection of HISILICON_IRQ_MBIGEN conditional on PCI. Cc: Ma Jun <majun258@huawei.com> Cc: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2016-08-10arm64: Kconfig: select ALPINE_MSI only if PCI is selectedSudeep Holla
Even when PCI is disabled, ARCH_ALPINE selects ALPINE_MSI triggerring the following config warning: warning: (ARCH_ALPINE) selects ALPINE_MSI which has unmet direct dependencies (PCI) This patch makes selection of ALPINE_MSI conditional on PCI. Cc: Arnd Bergmann <arnd@arndb.de> Acked-by: Antoine Tenart <antoine.tenart@free-electrons.com> Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2016-08-10ARM: dts: realview: Fix PBX-A9 cache descriptionRobin Murphy
Clearly QEMU is very permissive in how its PL310 model may be set up, but the real hardware turns out to be far more particular about things actually being correct. Fix up the DT description so that the real thing actually boots: - The arm,data-latency and arm,tag-latency properties need 3 cells to be valid, otherwise we end up retaining the default 8-cycle latencies which leads pretty quickly to lockup. - The arm,dirty-latency property is only relevant to L210/L220, so get rid of it. - The cache geometry override also leads to lockup and/or general misbehaviour. Irritatingly, the manual doesn't state the actual PL310 configuration, but based on the boardfile code and poking registers from the Boot Monitor, it would seem to be 8 sets of 16KB ways. With that, we can successfully boot to enjoy the fun of mismatched FPUs... Cc: stable@vger.kernel.org Signed-off-by: Robin Murphy <robin.murphy@arm.com> Tested-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2016-08-10ARM: tegra: fix erroneous address in dtsRalf Ramsauer
c90bb7b enabled the high speed UARTs of the Jetson TK1. Due to a merge quirk, wrong addresses were introduced. Fix it and use the correct addresses. Thierry let me know, that there is another patch (b5896f67ab3c in linux-next) in preparation which removes all the '0,' prefixes of unit addresses on Tegra124 and is planned to go upstream in 4.8, so this patch will get reverted then. But for the moment, this patch is necessary to fix current misbehaviour. Fixes: c90bb7b9b9 ("ARM: tegra: Add high speed UARTs to Jetson TK1 device tree") Signed-off-by: Ralf Ramsauer <ralf@ramses-pyramidenbau.de> Acked-by: Thierry Reding <thierry.reding@gmail.com> Cc: stable@vger.kernel.org # v4.7 Cc: linux-tegra@vger.kernel.org Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2016-08-10ARM: dts: add syscon compatible string for AP sysconLinus Walleij
This syscon needs to be looked up by clocks, flash protection and other consumers. Signed-off-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2016-08-10ARM: dts: add syscon compatible string for CP sysconLinus Walleij
This syscon needs to be looked up by flash protection, CLCD display output settings and other consumers. Signed-off-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2016-08-10ARM: oxnas: select reset controller frameworkArnd Bergmann
For unknown reasons, we have to enable three symbols for a platform to use a reset controller driver, otherwise we get a Kconfig warning: warning: (MACH_OX810SE) selects RESET_OXNAS which has unmet direct dependencies (RESET_CONTROLLER) This selects the other two symbols for oxnas. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Neil Armstrong <narmstrong@baylibre.com>
2016-08-10ARM: hide mach-*/ include for ARM_SINGLE_ARMV7MArnd Bergmann
The machine specific header files are exported for traditional platforms, but not for the ones that use ARCH_MULTIPLATFORM, as they could conflict with one another. In case of ARM_SINGLE_ARMV7M, we end up also exporting them, but that appears to be a mistake, and we should treat it the same way as ARCH_MULTIPLATFORM here. 'make W=1' warns about this because it passes -Wmissing-includes to gcc and the directories are not actually present. Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2016-08-10ARM: don't include removed directoriesArnd Bergmann
Three platforms used to have header files in include/mach that are now all gone, but the removed directories are still being included, which leads to -Wmissing-include-dirs warnings. This removes the extra -I flags. Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2016-08-10arm: oabi compat: add missing access checksDave Weinstein
Add access checks to sys_oabi_epoll_wait() and sys_oabi_semtimedop(). This fixes CVE-2016-3857, a local privilege escalation under CONFIG_OABI_COMPAT. Cc: stable@vger.kernel.org Reported-by: Chiachih Wu <wuchiachih@gmail.com> Reviewed-by: Kees Cook <keescook@chromium.org> Reviewed-by: Nicolas Pitre <nico@linaro.org> Signed-off-by: Dave Weinstein <olorin@google.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-10Merge branch 'for-linus-4.8' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs Pull btrfs fixes from Chris Mason: "Some fixes for btrfs send/recv and fsync from Filipe and Robbie Ko. Bonus points to Filipe for already having xfstests in place for many of these" * 'for-linus-4.8' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: Btrfs: remove unused function btrfs_add_delayed_qgroup_reserve() Btrfs: improve performance on fsync against new inode after rename/unlink Btrfs: be more precise on errors when getting an inode from disk Btrfs: send, don't bug on inconsistent snapshots Btrfs: send, avoid incorrect leaf accesses when sending utimes operations Btrfs: send, fix invalid leaf accesses due to incorrect utimes operations Btrfs: send, fix warning due to late freeing of orphan_dir_info structures Btrfs: incremental send, fix premature rmdir operations Btrfs: incremental send, fix invalid paths for rename operations Btrfs: send, add missing error check for calls to path_loop() Btrfs: send, fix failure to move directories with the same name around Btrfs: add missing check for writeback errors on fsync
2016-08-10Merge tag 'metag-for-v4.8-rc2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jhogan/metag Pull metag architecture fix from James Hogan: "A single fix for a boot crash since a commit in the merge window. Metag was unusual in calling show_mem() early, before setup_per_cpu_pageset(), which is no longer safe. It doesn't add much value to the log, so the fix just drops the call" * tag 'metag-for-v4.8-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/jhogan/metag: metag: Drop show_mem() from mem_init()
2016-08-10get_maintainer: Don't check if STDIN exists in a VCS repositoryJoe Perches
If get_maintainer is not given any filename arguments on the command line, the standard input is read for a patch. But checking if a VCS has a file named &STDIN is not a good idea and fails. Verify the nominal input file is not &STDIN before checking the VCS. Fixes: 4cad35a7ca69 ("get_maintainer.pl: reduce need for command-line option -f") Reported-by: Christopher Covington <cov@codeaurora.org> Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-10x86/mm/pkeys: Fix compact mode by removing protection keys' XSAVE buffer ↵Dave Hansen
manipulation The Memory Protection Keys "rights register" (PKRU) is XSAVE-managed, and is saved/restored along with the FPU state. When kernel code accesses FPU regsisters, it does a delicate dance with preempt. Otherwise, the context switching code can get confused as to whether the most up-to-date state is in the registers themselves or in the XSAVE buffer. But, PKRU is not a normal FPU register. Using it does not generate the normal device-not-available (#NM) exceptions which means we can not manage it lazily, and the kernel completley disallows using lazy mode when it is enabled. The dance with preempt *only* occurs when managing the FPU lazily. Since we never manage PKRU lazily, we do not have to do the dance with preempt; we can access it directly. Doing it this way saves a ton of complicated code (and is faster too). Further, the XSAVES reenabling failed to patch a bit of code in fpu__xfeature_set_state() the checked for compacted buffers. That check caused fpu__xfeature_set_state() to silently refuse to work when the kernel is using compacted XSAVE buffers. This broke execute-only and future pkey_mprotect() support when using compact XSAVE buffers. But, removing fpu__xfeature_set_state() gets rid of this issue, in addition to the nice cleanup and speedup. This fixes the same thing as a fix that Sai posted: https://lkml.org/lkml/2016/7/25/637 The fix that he posted is a much more obviously correct, but I think we should just do this instead. Reported-by: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Dave Hansen <dave@sr71.net> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com> Cc: Ravi Shankar <ravi.v.shankar@intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Yu-Cheng Yu <yu-cheng.yu@intel.com> Link: http://lkml.kernel.org/r/20160727232040.7D060DAD@viggo.jf.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-08-10x86/build: Reduce the W=1 warnings noise when compiling x86 syscall tablesValdis Kletnieks
Building an X86_64 kernel with W=1 throws a total of 9,948 lines of warnings of this form for both 32-bit and 64-bit syscall tables. Given that the entire rest of the build for my config only generates 8,375 lines of output, this is a big reduction in the warnings generated. The warnings follow this pattern: ./arch/x86/include/generated/asm/syscalls_32.h:885:21: warning: initialized field overwritten [-Woverride-init] __SYSCALL_I386(379, compat_sys_pwritev2, ) ^ arch/x86/entry/syscall_32.c:13:46: note: in definition of macro '__SYSCALL_I386' #define __SYSCALL_I386(nr, sym, qual) [nr] = sym, ^~~ ./arch/x86/include/generated/asm/syscalls_32.h:885:21: note: (near initialization for 'ia32_sys_call_table[379]') __SYSCALL_I386(379, compat_sys_pwritev2, ) ^ arch/x86/entry/syscall_32.c:13:46: note: in definition of macro '__SYSCALL_I386' #define __SYSCALL_I386(nr, sym, qual) [nr] = sym, Since we intentionally build the syscall tables this way, ignore that one warning in the two files. Signed-off-by: Valdis Kletnieks <valdis.kletnieks@vt.edu> 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: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/7464.1470021890@turing-police.cc.vt.edu Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-08-10x86/platform/UV: Fix kernel panic running RHEL kdump kernel on UV systemsMike Travis
The latest UV kernel support panics when RHEL7 kexec's the kdump kernel to make a dumpfile. This patch fixes the problem by turning off all UV support if NUMA is off. Tested-by: Frank Ramsay <framsay@sgi.com> Tested-by: John Estabrook <estabrook@sgi.com> Signed-off-by: Mike Travis <travis@sgi.com> Reviewed-by: Dimitri Sivanich <sivanich@sgi.com> Reviewed-by: Nathan Zimmer <nzimmer@sgi.com> Cc: Alex Thorlton <athorlton@sgi.com> Cc: Andrew Banman <abanman@sgi.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Russ Anderson <rja@sgi.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20160801184050.577755634@asylum.americas.sgi.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-08-10x86/platform/UV: Fix problem with UV4 BIOS providing incorrect PXM valuesMike Travis
There are some circumstances where the UV4 BIOS cannot provide the correct Proximity Node values to associate with specific Sockets and Physical Nodes. The decision was made to remove these values from BIOS and for the kernel to get these values from the standard ACPI tables. Tested-by: Frank Ramsay <framsay@sgi.com> Tested-by: John Estabrook <estabrook@sgi.com> Signed-off-by: Mike Travis <travis@sgi.com> Reviewed-by: Dimitri Sivanich <sivanich@sgi.com> Reviewed-by: Nathan Zimmer <nzimmer@sgi.com> Cc: Alex Thorlton <athorlton@sgi.com> Cc: Andrew Banman <abanman@sgi.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Russ Anderson <rja@sgi.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20160801184050.414210079@asylum.americas.sgi.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-08-10x86/platform/UV: Fix bug with iounmap() of the UV4 EFI System Table causing ↵Mike Travis
a crash Save the uv_systab::size field before doing the iounmap() of the struct pointer, to avoid a NULL dereference crash. Tested-by: Frank Ramsay <framsay@sgi.com> Tested-by: John Estabrook <estabrook@sgi.com> Signed-off-by: Mike Travis <travis@sgi.com> Reviewed-by: Dimitri Sivanich <sivanich@sgi.com> Reviewed-by: Nathan Zimmer <nzimmer@sgi.com> Cc: Alex Thorlton <athorlton@sgi.com> Cc: Andrew Banman <abanman@sgi.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Russ Anderson <rja@sgi.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20160801184050.250424783@asylum.americas.sgi.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-08-10x86/platform/UV: Fix problem with UV4 Socket IDs not being contiguousMike Travis
The UV4 Socket IDs are not guaranteed to equate to Node values which can cause the GAM (Global Addressable Memory) table lookups to fail. Fix this by using an independent index into the GAM table instead of the Socket ID to reference the base address. Tested-by: Frank Ramsay <framsay@sgi.com> Tested-by: John Estabrook <estabrook@sgi.com> Signed-off-by: Mike Travis <travis@sgi.com> Reviewed-by: Dimitri Sivanich <sivanich@sgi.com> Reviewed-by: Nathan Zimmer <nzimmer@sgi.com> Cc: Alex Thorlton <athorlton@sgi.com> Cc: Andrew Banman <abanman@sgi.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Russ Anderson <rja@sgi.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20160801184050.048755337@asylum.americas.sgi.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-08-10x86/entry: Clarify the RF saving/restoring situation with SYSCALL/SYSRETBorislav Petkov
Clarify why exactly RF cannot be restored properly by SYSRET to avoid confusion. No functionality change. Signed-off-by: Borislav Petkov <bp@suse.de> Acked-by: Andy Lutomirski <luto@amacapital.net> 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: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20160803171429.GA2590@nazgul.tnic Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-08-10x86/mm: Disable preemption during CR3 read+writeSebastian Andrzej Siewior
There's a subtle preemption race on UP kernels: Usually current->mm (and therefore mm->pgd) stays the same during the lifetime of a task so it does not matter if a task gets preempted during the read and write of the CR3. But then, there is this scenario on x86-UP: TaskA is in do_exit() and exit_mm() sets current->mm = NULL followed by: -> mmput() -> exit_mmap() -> tlb_finish_mmu() -> tlb_flush_mmu() -> tlb_flush_mmu_tlbonly() -> tlb_flush() -> flush_tlb_mm_range() -> __flush_tlb_up() -> __flush_tlb() -> __native_flush_tlb() At this point current->mm is NULL but current->active_mm still points to the "old" mm. Let's preempt taskA _after_ native_read_cr3() by taskB. TaskB has its own mm so CR3 has changed. Now preempt back to taskA. TaskA has no ->mm set so it borrows taskB's mm and so CR3 remains unchanged. Once taskA gets active it continues where it was interrupted and that means it writes its old CR3 value back. Everything is fine because userland won't need its memory anymore. Now the fun part: Let's preempt taskA one more time and get back to taskB. This time switch_mm() won't do a thing because oldmm (->active_mm) is the same as mm (as per context_switch()). So we remain with a bad CR3 / PGD and return to userland. The next thing that happens is handle_mm_fault() with an address for the execution of its code in userland. handle_mm_fault() realizes that it has a PTE with proper rights so it returns doing nothing. But the CPU looks at the wrong PGD and insists that something is wrong and faults again. And again. And one more time… This pagefault circle continues until the scheduler gets tired of it and puts another task on the CPU. It gets little difficult if the task is a RT task with a high priority. The system will either freeze or it gets fixed by the software watchdog thread which usually runs at RT-max prio. But waiting for the watchdog will increase the latency of the RT task which is no good. Fix this by disabling preemption across the critical code section. Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Rik van Riel <riel@redhat.com> Acked-by: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Borislav Petkov <bp@suse.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: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-mm@kvack.org Cc: stable@vger.kernel.org Link: http://lkml.kernel.org/r/1470404259-26290-1-git-send-email-bigeasy@linutronix.de [ Prettified the changelog. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-08-10selftests/powerpc: Specify we expect to build with std=gnu99Michael Ellerman
We have some tests that assume we're using std=gnu99, which is fine on most compilers, but some old compilers use a different default. So make it explicit that we want to use std=gnu99. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-08-10ALSA: hda - Manage power well properly for resumeTakashi Iwai
For SKL and later Intel chips, we control the power well per codec basis via link_power callback since the commit [03b135cebc47: ALSA: hda - remove dependency on i915 power well for SKL]. However, there are a few exceptional cases where the gfx registers are accessed from the audio driver: namely the wakeup override bit toggling at (both system and runtime) resume. This seems causing a kernel warning when accessed during the power well down (and likely resulting in the bogus register accesses). This patch puts the proper power up / down sequence around the resume code so that the wakeup bit is fiddled properly while the power is up. (The other callback, sync_audio_rate, is used only in the PCM callback, so it's guaranteed in the power-on.) Also, by this proper power up/down, the instantaneous flip of wakeup bit in the resume callback that was introduced by the commit [033ea349a7cd: ALSA: hda - Fix Skylake codec timeout] becomes superfluous, as snd_hdac_display_power() already does it. So we can clean it up together. Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=96214 Fixes: 03b135cebc47 ('ALSA: hda - remove dependency on i915 power well for SKL') Cc: <stable@vger.kernel.org> # v4.2+ Tested-by: Hans de Goede <hdegoede@redhat.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2016-08-10powerpc/vdso: Fix build rules to rebuild vdsos correctlyNicholas Piggin
When using if_changed, we need to add FORCE as a dependency (see Documentation/kbuild/makefiles.txt) otherwise we don't get command line change checking amongst other things. This has resulted in vdsos not being rebuilt when switching between big and little endian. The vdso64/32ld commands have to be changed around to avoid pulling FORCE into the linker command line (code copied from x86). Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-08-10powerpc/Makefile: Use cflags-y/aflags-y for setting endian optionsMichael Ellerman
When we introduced the little endian support, we added the endian flags to CC directly using override. I don't know the history of why we did that, I suspect no one does. Although this mostly works, it has one bug, which is that CROSS32CC doesn't get -mbig-endian. That means when the compiler is little endian by default and the user is building big endian, vdso32 is incorrectly compiled as little endian and the kernel fails to build. Instead we can add the endian flags to cflags-y/aflags-y, and then append those to KBUILD_CFLAGS/KBUILD_AFLAGS. This has the advantage of being 1) less ugly, 2) the documented way of adding flags in the arch Makefile and 3) it fixes building vdso32 with a LE toolchain. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-08-10x86/mm/KASLR: Increase BRK pages for KASLR memory randomizationThomas Garnier
Default implementation expects 6 pages maximum are needed for low page allocations. If KASLR memory randomization is enabled, the worse case of e820 layout would require 12 pages (no large pages). It is due to the PUD level randomization and the variable e820 memory layout. This bug was found while doing extensive testing of KASLR memory randomization on different type of hardware. Signed-off-by: Thomas Garnier <thgarnie@google.com> Cc: Aleksey Makarov <aleksey.makarov@linaro.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Baoquan He <bhe@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Borislav Petkov <bp@suse.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Dave Young <dyoung@redhat.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Fabian Frederick <fabf@skynet.be> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Joerg Roedel <jroedel@suse.de> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Lv Zheng <lv.zheng@intel.com> Cc: Mark Salter <msalter@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rafael J . Wysocki <rafael.j.wysocki@intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Toshi Kani <toshi.kani@hp.com> Cc: kernel-hardening@lists.openwall.com Fixes: 021182e52fe0 ("Enable KASLR for physical mapping memory regions") Link: http://lkml.kernel.org/r/1470762665-88032-2-git-send-email-thgarnie@google.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-08-10x86/mm/KASLR: Fix physical memory calculation on KASLR memory randomizationThomas Garnier
Initialize KASLR memory randomization after max_pfn is initialized. Also ensure the size is rounded up. It could create problems on machines with more than 1Tb of memory on certain random addresses. Signed-off-by: Thomas Garnier <thgarnie@google.com> Cc: Aleksey Makarov <aleksey.makarov@linaro.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Baoquan He <bhe@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Borislav Petkov <bp@suse.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Dave Young <dyoung@redhat.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Fabian Frederick <fabf@skynet.be> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Joerg Roedel <jroedel@suse.de> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Lv Zheng <lv.zheng@intel.com> Cc: Mark Salter <msalter@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rafael J . Wysocki <rafael.j.wysocki@intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Toshi Kani <toshi.kani@hp.com> Cc: kernel-hardening@lists.openwall.com Fixes: 021182e52fe0 ("Enable KASLR for physical mapping memory regions") Link: http://lkml.kernel.org/r/1470762665-88032-1-git-send-email-thgarnie@google.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-08-10x86/hpet: Fix /dev/rtc breakage caused by RTC cleanupArnd Bergmann
Ville Syrjälä reports "The first time I run hwclock after rebooting I get this: open("/dev/rtc", O_RDONLY) = 3 ioctl(3, PHN_SET_REGS or RTC_UIE_ON, 0) = 0 select(4, [3], NULL, NULL, {10, 0}) = 0 (Timeout) ioctl(3, PHN_NOT_OH or RTC_UIE_OFF, 0) = 0 close(3) = 0 On all subsequent runs I get this: open("/dev/rtc", O_RDONLY) = 3 ioctl(3, PHN_SET_REGS or RTC_UIE_ON, 0) = -1 EINVAL (Invalid argument) ioctl(3, RTC_RD_TIME, 0x7ffd76b3ae70) = -1 EINVAL (Invalid argument) close(3) = 0" This was caused by a stupid typo in a patch that should have been a simple rename to move around contents of a header file, but accidentally wrote zeroes into the rtc rather than reading from it: 463a86304cae ("char/genrtc: x86: remove remnants of asm/rtc.h") Reported-by: Ville Syrjälä <ville.syrjala@linux.intel.com> Tested-by: Jarkko Nikula <jarkko.nikula@linux.intel.com> Tested-by: Ville Syrjälä <ville.syrjala@linux.intel.com> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Cc: Alessandro Zummo <a.zummo@towertech.it> Cc: Alexandre Belloni <alexandre.belloni@free-electrons.com> Cc: Borislav Petkov <bp@suse.de> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: rtc-linux@googlegroups.com Fixes: 463a86304cae ("char/genrtc: x86: remove remnants of asm/rtc.h") Link: http://lkml.kernel.org/r/20160809195528.1604312-1-arnd@arndb.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-08-10Merge branch 'linus' into timers/urgent, to pick up fixesIngo Molnar
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-08-10x86, kasan, ftrace: Put APIC interrupt handlers into .irqentry.textAlexander Potapenko
Dmitry Vyukov has reported unexpected KASAN stackdepot growth: https://github.com/google/kasan/issues/36 ... which is caused by the APIC handlers not being present in .irqentry.text: When building with CONFIG_FUNCTION_GRAPH_TRACER=y or CONFIG_KASAN=y, put the APIC interrupt handlers into the .irqentry.text section. This is needed because both KASAN and function graph tracer use __irqentry_text_start and __irqentry_text_end to determine whether a function is an IRQ entry point. Reported-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Alexander Potapenko <glider@google.com> 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: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: aryabinin@virtuozzo.com Cc: kasan-dev@googlegroups.com Cc: kcc@google.com Cc: rostedt@goodmis.org Link: http://lkml.kernel.org/r/1468575763-144889-1-git-send-email-glider@google.com [ Minor edits. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-08-10locking/pvqspinlock: Fix a bug in qstat_read()Pan Xinhui
It's obviously wrong to set stat to NULL. So lets remove it. Otherwise it is always zero when we check the latency of kick/wake. Signed-off-by: Pan Xinhui <xinhui.pan@linux.vnet.ibm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Waiman Long <Waiman.Long@hpe.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1468405414-3700-1-git-send-email-xinhui.pan@linux.vnet.ibm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-08-10locking/pvqspinlock: Fix double hash raceWanpeng Li
When the lock holder vCPU is racing with the queue head: CPU 0 (lock holder) CPU1 (queue head) =================== ================= spin_lock(); spin_lock(); pv_kick_node(): pv_wait_head_or_lock(): if (!lp) { lp = pv_hash(lock, pn); xchg(&l->locked, _Q_SLOW_VAL); } WRITE_ONCE(pn->state, vcpu_halted); cmpxchg(&pn->state, vcpu_halted, vcpu_hashed); WRITE_ONCE(l->locked, _Q_SLOW_VAL); (void)pv_hash(lock, pn); In this case, lock holder inserts the pv_node of queue head into the hash table and set _Q_SLOW_VAL unnecessary. This patch avoids it by restoring/setting vcpu_hashed state after failing adaptive locking spinning. Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Pan Xinhui <xinhui.pan@linux.vnet.ibm.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Waiman Long <Waiman.Long@hpe.com> Link: http://lkml.kernel.org/r/1468484156-4521-1-git-send-email-wanpeng.li@hotmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-08-10locking/qrwlock: Fix write unlock bug on big endian systemspan xinhui
This patch aims to get rid of endianness in queued_write_unlock(). We want to set __qrwlock->wmode to NULL, however the address is not &lock->cnts in big endian machine. That causes queued_write_unlock() write NULL to the wrong field of __qrwlock. So implement __qrwlock_write_byte() which returns the correct __qrwlock->wmode address. Suggested-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Pan Xinhui <xinhui.pan@linux.vnet.ibm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Waiman.Long@hpe.com Cc: arnd@arndb.de Cc: boqun.feng@gmail.com Cc: will.deacon@arm.com Link: http://lkml.kernel.org/r/1468835259-4486-1-git-send-email-xinhui.pan@linux.vnet.ibm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-08-10Merge branch 'linus' into locking/urgent, to pick up fixesIngo Molnar
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-08-10sched/deadline: Fix lock pinning warning during CPU hotplugWanpeng Li
The following warning can be triggered by hot-unplugging the CPU on which an active SCHED_DEADLINE task is running on: WARNING: CPU: 0 PID: 0 at kernel/locking/lockdep.c:3531 lock_release+0x690/0x6a0 releasing a pinned lock Call Trace: dump_stack+0x99/0xd0 __warn+0xd1/0xf0 ? dl_task_timer+0x1a1/0x2b0 warn_slowpath_fmt+0x4f/0x60 ? sched_clock+0x13/0x20 lock_release+0x690/0x6a0 ? enqueue_pushable_dl_task+0x9b/0xa0 ? enqueue_task_dl+0x1ca/0x480 _raw_spin_unlock+0x1f/0x40 dl_task_timer+0x1a1/0x2b0 ? push_dl_task.part.31+0x190/0x190 WARNING: CPU: 0 PID: 0 at kernel/locking/lockdep.c:3649 lock_unpin_lock+0x181/0x1a0 unpinning an unpinned lock Call Trace: dump_stack+0x99/0xd0 __warn+0xd1/0xf0 warn_slowpath_fmt+0x4f/0x60 lock_unpin_lock+0x181/0x1a0 dl_task_timer+0x127/0x2b0 ? push_dl_task.part.31+0x190/0x190 As per the comment before this code, its safe to drop the RQ lock here, and since we (potentially) change rq, unpin and repin to avoid the splat. Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com> [ Rewrote changelog. ] Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Juri Lelli <juri.lelli@arm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Luca Abeni <luca.abeni@unitn.it> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1470274940-17976-1-git-send-email-wanpeng.li@hotmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-08-10sched/cputime: Mitigate performance regression in times()/clock_gettime()Giovanni Gherdovich
Commit: 6e998916dfe3 ("sched/cputime: Fix clock_nanosleep()/clock_gettime() inconsistency") fixed a problem whereby clock_nanosleep() followed by clock_gettime() could allow a task to wake early. It addressed the problem by calling the scheduling classes update_curr() when the cputimer starts. Said change induced a considerable performance regression on the syscalls times() and clock_gettimes(CLOCK_PROCESS_CPUTIME_ID). There are some debuggers and applications that monitor their own performance that accidentally depend on the performance of these specific calls. This patch mitigates the performace loss by prefetching data in the CPU cache, as stalls due to cache misses appear to be where most time is spent in our benchmarks. Here are the performance gain of this patch over v4.7-rc7 on a Sandy Bridge box with 32 logical cores and 2 NUMA nodes. The test is repeated with a variable number of threads, from 2 to 4*num_cpus; the results are in seconds and correspond to the average of 10 runs; the percentage gain is computed with (before-after)/before so a positive value is an improvement (it's faster). The improvement varies between a few percents for 5-20 threads and more than 10% for 2 or >20 threads. pound_clock_gettime: threads 4.7-rc7 patched 4.7-rc7 [num] [secs] [secs (percent)] 2 3.48 3.06 ( 11.83%) 5 3.33 3.25 ( 2.40%) 8 3.37 3.26 ( 3.30%) 12 3.32 3.37 ( -1.60%) 21 4.01 3.90 ( 2.74%) 30 3.63 3.36 ( 7.41%) 48 3.71 3.11 ( 16.27%) 79 3.75 3.16 ( 15.74%) 110 3.81 3.25 ( 14.80%) 128 3.88 3.31 ( 14.76%) pound_times: threads 4.7-rc7 patched 4.7-rc7 [num] [secs] [secs (percent)] 2 3.65 3.25 ( 11.03%) 5 3.45 3.17 ( 7.92%) 8 3.52 3.22 ( 8.69%) 12 3.29 3.36 ( -2.04%) 21 4.07 3.92 ( 3.78%) 30 3.87 3.40 ( 12.17%) 48 3.79 3.16 ( 16.61%) 79 3.88 3.28 ( 15.42%) 110 3.90 3.38 ( 13.35%) 128 4.00 3.38 ( 15.45%) pound_clock_gettime and pound_clock_gettime are two benchmarks included in the MMTests framework. They launch a given number of threads which repeatedly call times() or clock_gettimes(). The results above can be reproduced with cloning MMTests from github.com and running the "poundtime" workload: $ git clone https://github.com/gormanm/mmtests.git $ cd mmtests $ cp configs/config-global-dhp__workload_poundtime config $ ./run-mmtests.sh --run-monitor $(uname -r) The above will run "poundtime" measuring the kernel currently running on the machine; Once a new kernel is installed and the machine rebooted, running again $ cd mmtests $ ./run-mmtests.sh --run-monitor $(uname -r) will produce results to compare with. A comparison table will be output with: $ cd mmtests/work/log $ ../../compare-kernels.sh the table will contain a lot of entries; grepping for "Amean" (as in "arithmetic mean") will give the tables presented above. The source code for the two benchmarks is reported at the end of this changelog for clairity. The cache misses addressed by this patch were found using a combination of `perf top`, `perf record` and `perf annotate`. The incriminated lines were found to be struct sched_entity *curr = cfs_rq->curr; and delta_exec = now - curr->exec_start; in the function update_curr() from kernel/sched/fair.c. This patch prefetches the data from memory just before update_curr is called in the interested execution path. A comparison of the total number of cycles before and after the patch follows; the data is obtained using `perf stat -r 10 -ddd <program>` running over the same sequence of number of threads used above (a positive gain is an improvement): threads cycles before cycles after gain 2 19,699,563,964 +-1.19% 17,358,917,517 +-1.85% 11.88% 5 47,401,089,566 +-2.96% 45,103,730,829 +-0.97% 4.85% 8 80,923,501,004 +-3.01% 71,419,385,977 +-0.77% 11.74% 12 112,326,485,473 +-0.47% 110,371,524,403 +-0.47% 1.74% 21 193,455,574,299 +-0.72% 180,120,667,904 +-0.36% 6.89% 30 315,073,519,013 +-1.64% 271,222,225,950 +-1.29% 13.92% 48 321,969,515,332 +-1.48% 273,353,977,321 +-1.16% 15.10% 79 337,866,003,422 +-0.97% 289,462,481,538 +-1.05% 14.33% 110 338,712,691,920 +-0.78% 290,574,233,170 +-0.77% 14.21% 128 348,384,794,006 +-0.50% 292,691,648,206 +-0.66% 15.99% A comparison of cache miss vs total cache loads ratios, before and after the patch (again from the `perf stat -r 10 -ddd <program>` tables): threads L1 misses/total*100 L1 misses/total*100 gain before after 2 7.43 +-4.90% 7.36 +-4.70% 0.94% 5 13.09 +-4.74% 13.52 +-3.73% -3.28% 8 13.79 +-5.61% 12.90 +-3.27% 6.45% 12 11.57 +-2.44% 8.71 +-1.40% 24.72% 21 12.39 +-3.92% 9.97 +-1.84% 19.53% 30 13.91 +-2.53% 11.73 +-2.28% 15.67% 48 13.71 +-1.59% 12.32 +-1.97% 10.14% 79 14.44 +-0.66% 13.40 +-1.06% 7.20% 110 15.86 +-0.50% 14.46 +-0.59% 8.83% 128 16.51 +-0.32% 15.06 +-0.78% 8.78% As a final note, the following shows the evolution of performance figures in the "poundtime" benchmark and pinpoints commit 6e998916dfe3 ("sched/cputime: Fix clock_nanosleep()/clock_gettime() inconsistency") as a major source of degradation, mostly unaddressed to this day (figures expressed in seconds). pound_clock_gettime: threads parent of 6e998916dfe3 4.7-rc7 6e998916dfe3 itself 2 2.23 3.68 ( -64.56%) 3.48 (-55.48%) 5 2.83 3.78 ( -33.42%) 3.33 (-17.43%) 8 2.84 4.31 ( -52.12%) 3.37 (-18.76%) 12 3.09 3.61 ( -16.74%) 3.32 ( -7.17%) 21 3.14 4.63 ( -47.36%) 4.01 (-27.71%) 30 3.28 5.75 ( -75.37%) 3.63 (-10.80%) 48 3.02 6.05 (-100.56%) 3.71 (-22.99%) 79 2.88 6.30 (-118.90%) 3.75 (-30.26%) 110 2.95 6.46 (-119.00%) 3.81 (-29.24%) 128 3.05 6.42 (-110.08%) 3.88 (-27.04%) pound_times: threads parent of 6e998916dfe3 4.7-rc7 6e998916dfe3 itself 2 2.27 3.73 ( -64.71%) 3.65 (-61.14%) 5 2.78 3.77 ( -35.56%) 3.45 (-23.98%) 8 2.79 4.41 ( -57.71%) 3.52 (-26.05%) 12 3.02 3.56 ( -17.94%) 3.29 ( -9.08%) 21 3.10 4.61 ( -48.74%) 4.07 (-31.34%) 30 3.33 5.75 ( -72.53%) 3.87 (-16.01%) 48 2.96 6.06 (-105.04%) 3.79 (-28.10%) 79 2.88 6.24 (-116.83%) 3.88 (-34.81%) 110 2.98 6.37 (-114.08%) 3.90 (-31.12%) 128 3.10 6.35 (-104.61%) 4.00 (-28.87%) The source code of the two benchmarks follows. To compile the two: NR_THREADS=42 for FILE in pound_times pound_clock_gettime; do gcc -lrt -O2 -lpthread -DNUM_THREADS=$NR_THREADS $FILE.c -o $FILE done ==== BEGIN pound_times.c ==== struct tms start; void *pound (void *threadid) { struct tms end; int oldutime = 0; int utime; int i; for (i = 0; i < 5000000 / NUM_THREADS; i++) { times(&end); utime = ((int)end.tms_utime - (int)start.tms_utime); if (oldutime > utime) { printf("utime decreased, was %d, now %d!\n", oldutime, utime); } oldutime = utime; } pthread_exit(NULL); } int main() { pthread_t th[NUM_THREADS]; long i; times(&start); for (i = 0; i < NUM_THREADS; i++) { pthread_create (&th[i], NULL, pound, (void *)i); } pthread_exit(NULL); return 0; } ==== END pound_times.c ==== ==== BEGIN pound_clock_gettime.c ==== void *pound (void *threadid) { struct timespec ts; int rc, i; unsigned long prev = 0, this = 0; for (i = 0; i < 5000000 / NUM_THREADS; i++) { rc = clock_gettime(CLOCK_PROCESS_CPUTIME_ID, &ts); if (rc < 0) perror("clock_gettime"); this = (ts.tv_sec * 1000000000) + ts.tv_nsec; if (0 && this < prev) printf("%lu ns timewarp at iteration %d\n", prev - this, i); prev = this; } pthread_exit(NULL); } int main() { pthread_t th[NUM_THREADS]; long rc, i; pid_t pgid; for (i = 0; i < NUM_THREADS; i++) { rc = pthread_create(&th[i], NULL, pound, (void *)i); if (rc < 0) perror("pthread_create"); } pthread_exit(NULL); return 0; } ==== END pound_clock_gettime.c ==== Suggested-by: Mike Galbraith <mgalbraith@suse.de> Signed-off-by: Giovanni Gherdovich <ggherdovich@suse.cz> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stanislaw Gruszka <sgruszka@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1470385316-15027-2-git-send-email-ggherdovich@suse.cz Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-08-10sched/fair: Fix typo in sync_throttle()Xunlei Pang
We should update cfs_rq->throttled_clock_task, not pcfs_rq->throttle_clock_task. The effects of this bug was probably occasionally erratic group scheduling, particularly in cgroups-intense workloads. Signed-off-by: Xunlei Pang <xlpang@redhat.com> [ Added changelog. ] Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Fixes: 55e16d30bd99 ("sched/fair: Rework throttle_count sync") Link: http://lkml.kernel.org/r/1468050862-18864-1-git-send-email-xlpang@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-08-10sched/deadline: Fix wrap-around in DL heapTommaso Cucinotta
Current code in cpudeadline.c has a bug in re-heapifying when adding a new element at the end of the heap, because a deadline value of 0 is temporarily set in the new elem, then cpudl_change_key() is called with the actual elem deadline as param. However, the function compares the new deadline to set with the one previously in the elem, which is 0. So, if current absolute deadlines grew so much to have negative values as s64, the comparison in cpudl_change_key() makes the wrong decision. Instead, as from dl_time_before(), the kernel should handle correctly abs deadlines wrap-arounds. This patch fixes the problem with a minimally invasive change that forces cpudl_change_key() to heapify up in this case. Signed-off-by: Tommaso Cucinotta <tommaso.cucinotta@sssup.it> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Luca Abeni <luca.abeni@unitn.it> Cc: Juri Lelli <juri.lelli@arm.com> Cc: Juri Lelli <juri.lelli@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1468921493-10054-2-git-send-email-tommaso.cucinotta@sssup.it Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-08-10perf/core: Set cgroup in CPU contexts for new cgroup eventsDavid Carrillo-Cisneros
There's a perf stat bug easy to observer on a machine with only one cgroup: $ perf stat -e cycles -I 1000 -C 0 -G / # time counts unit events 1.000161699 <not counted> cycles / 2.000355591 <not counted> cycles / 3.000565154 <not counted> cycles / 4.000951350 <not counted> cycles / We'd expect some output there. The underlying problem is that there is an optimization in perf_cgroup_sched_{in,out}() that skips the switch of cgroup events if the old and new cgroups in a task switch are the same. This optimization interacts with the current code in two ways that cause a CPU context's cgroup (cpuctx->cgrp) to be NULL even if a cgroup event matches the current task. These are: 1. On creation of the first cgroup event in a CPU: In current code, cpuctx->cpu is only set in perf_cgroup_sched_in, but due to the aforesaid optimization, perf_cgroup_sched_in will run until the next cgroup switches in that CPU. This may happen late or never happen, depending on system's number of cgroups, CPU load, etc. 2. On deletion of the last cgroup event in a cpuctx: In list_del_event, cpuctx->cgrp is set NULL. Any new cgroup event will not be sched in because cpuctx->cgrp == NULL until a cgroup switch occurs and perf_cgroup_sched_in is executed (updating cpuctx->cgrp). This patch fixes both problems by setting cpuctx->cgrp in list_add_event, mirroring what list_del_event does when removing a cgroup event from CPU context, as introduced in: commit 68cacd29167b ("perf_events: Fix stale ->cgrp pointer in update_cgrp_time_from_cpuctx()") With this patch, cpuctx->cgrp is always set/clear when installing/removing the first/last cgroup event in/from the CPU context. With cpuctx->cgrp correctly set, event_filter_match works as intended when events are sched in/out. After the fix, the output is as expected: $ perf stat -e cycles -I 1000 -a -G / # time counts unit events 1.004699159 627342882 cycles / 2.007397156 615272690 cycles / 3.010019057 616726074 cycles / Signed-off-by: David Carrillo-Cisneros <davidcc@google.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Kan Liang <kan.liang@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul Turner <pjt@google.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vegard Nossum <vegard.nossum@gmail.com> Cc: Vince Weaver <vincent.weaver@maine.edu> Link: http://lkml.kernel.org/r/1470124092-113192-1-git-send-email-davidcc@google.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-08-10perf/core: Fix sideband list-iteration vs. event ordering NULL pointer ↵Peter Zijlstra
deference crash Vegard Nossum reported that perf fuzzing generates a NULL pointer dereference crash: > Digging a bit deeper into this, it seems the event itself is getting > created by perf_event_open() and it gets added to the pmu_event_list > through: > > perf_event_open() > - perf_event_alloc() > - account_event() > - account_pmu_sb_event() > - attach_sb_event() > > so at this point the event is being attached but its ->ctx is still > NULL. It seems like ->ctx is set just a bit later in > perf_event_open(), though. > > But before that, __schedule() comes along and creates a stack trace > similar to the one above: > > __schedule() > - __perf_event_task_sched_out() > - perf_iterate_sb() > - perf_iterate_sb_cpu() > - event_filter_match() > - perf_cgroup_match() > - __get_cpu_context() > - (dereference ctx which is NULL) > > So I guess the question is... should the event be attached (= put on > the list) before ->ctx gets set? Or should the cgroup code check for a > NULL ->ctx? The latter seems like the simplest solution. Moving the list-add later creates a bit of a mess. Reported-by: Vegard Nossum <vegard.nossum@gmail.com> Tested-by: Vegard Nossum <vegard.nossum@gmail.com> Tested-by: Vince Weaver <vincent.weaver@maine.edu> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: David Carrillo-Cisneros <davidcc@google.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Kan Liang <kan.liang@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Fixes: f2fb6bef9251 ("perf/core: Optimize side-band event delivery") Link: http://lkml.kernel.org/r/20160804123724.GN6862@twins.programming.kicks-ass.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-08-10x86/timers/apic: Inform TSC deadline clockevent device about recalibrationNicolai Stange
This patch eliminates a source of imprecise APIC timer interrupts, which imprecision may result in double interrupts or even late interrupts. The TSC deadline clockevent devices' configuration and registration happens before the TSC frequency calibration is refined in tsc_refine_calibration_work(). This results in the TSC clocksource and the TSC deadline clockevent devices being configured with slightly different frequencies: the former gets the refined one and the latter are configured with the inaccurate frequency detected earlier by means of the "Fast TSC calibration using PIT". Within the APIC code, introduce the notifier function lapic_update_tsc_freq() which reconfigures all per-CPU TSC deadline clockevent devices with the current tsc_khz. Call it from the TSC code after TSC calibration refinement has happened. Signed-off-by: Nicolai Stange <nicstange@gmail.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Thomas Gleixner <tglx@linutronix.de> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Borislav Petkov <bp@suse.de> Cc: Christopher S. Hall <christopher.s.hall@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com> Cc: Len Brown <len.brown@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Viresh Kumar <viresh.kumar@linaro.org> Link: http://lkml.kernel.org/r/20160714152255.18295-3-nicstange@gmail.com [ Pushed #ifdef CONFIG_X86_LOCAL_APIC into header, improved changelog. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-08-10x86/timers/apic: Fix imprecise timer interrupts by eliminating TSC ↵Nicolai Stange
clockevents frequency roundoff error I noticed the following bug/misbehavior on certain Intel systems: with a single task running on a NOHZ CPU on an Intel Haswell, I recognized that I did not only get the one expected local_timer APIC interrupt, but two per second at minimum. (!) Further tracing showed that the first one precedes the programmed deadline by up to ~50us and hence, it did nothing except for reprogramming the TSC deadline clockevent device to trigger shortly thereafter again. The reason for this is imprecise calibration, the timeout we program into the APIC results in 'too short' timer interrupts. The core (hr)timer code notices this (because it has a precise ktime source and sees the short interrupt) and fixes it up by programming an additional very short interrupt period. This is obviously suboptimal. The reason for the imprecise calibration is twofold, and this patch fixes the first reason: In setup_APIC_timer(), the registered clockevent device's frequency is calculated by first dividing tsc_khz by TSC_DIVISOR and multiplying it with 1000 afterwards: (tsc_khz / TSC_DIVISOR) * 1000 The multiplication with 1000 is done for converting from kHz to Hz and the division by TSC_DIVISOR is carried out in order to make sure that the final result fits into an u32. However, with the order given in this calculation, the roundoff error introduced by the division gets magnified by a factor of 1000 by the following multiplication. To fix it, reversing the order of the division and the multiplication a la: (tsc_khz * 1000) / TSC_DIVISOR ... reduces the roundoff error already. Furthermore, if TSC_DIVISOR divides 1000, associativity holds: (tsc_khz * 1000) / TSC_DIVISOR = tsc_khz * (1000 / TSC_DIVISOR) and thus, the roundoff error even vanishes and the whole operation can be carried out within 32 bits. The powers of two that divide 1000 are 2, 4 and 8. A value of 8 for TSC_DIVISOR still allows for TSC frequencies up to 2^32 / 10^9ns * 8 = 34.4GHz which is way larger than anything to expect in the next years. Thus we also replace the current TSC_DIVISOR value of 32 by 8. Reverse the order of the divison and the multiplication in the calculation of the registered clockevent device's frequency. Signed-off-by: Nicolai Stange <nicstange@gmail.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Borislav Petkov <bp@suse.de> Cc: Christopher S. Hall <christopher.s.hall@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com> Cc: Len Brown <len.brown@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Viresh Kumar <viresh.kumar@linaro.org> Link: http://lkml.kernel.org/r/20160714152255.18295-2-nicstange@gmail.com [ Improved changelog. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-08-10powerpc/32: Fix crash during static key initBenjamin Herrenschmidt
We cannot do those initializations from apply_feature_fixups() as this function runs in a very restricted environment on 32-bit where the kernel isn't running at its linked address and the PTRRELOC() macro must be used for any global accesss. Instead, split them into a separtate steup_feature_keys() function which is called in a more suitable spot on ppc32. Fixes: 309b315b6ec6 ("powerpc: Call jump_label_init() in apply_feature_fixups()") Reported-and-tested-by: Christian Kujau <lists@nerdbynature.de> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-08-10powerpc: Update obsolete comment in setup_32.c about early_init()Benjamin Herrenschmidt
We don't identify the machine type anymore... Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-08-10powerpc: Print the kernel load address at the end of prom_init()Benjamin Herrenschmidt
This makes it easier to debug crashes that happen very early before the kernel takes over Open Firmware by allowing us to relate the OF reported crashing addresses to offsets within the kernel. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-08-10powerpc/ptrace: Fix coredump since ptrace TM changesCyril Bur
Commit 8d460f6156cd ("powerpc/process: Add the function flush_tmregs_to_thread") added flush_tmregs_to_thread() and included the assumption that it would only be called for a task which is not current. Although this is correct for ptrace, when generating a core dump, some of the routines which call flush_tmregs_to_thread() are called. This leads to a WARNing such as: Not expecting ptrace on self: TM regs may be incorrect ------------[ cut here ]------------ WARNING: CPU: 123 PID: 7727 at arch/powerpc/kernel/process.c:1088 flush_tmregs_to_thread+0x78/0x80 CPU: 123 PID: 7727 Comm: libvirtd Not tainted 4.8.0-rc1-gcc6x-g61e8a0d #1 task: c000000fe631b600 task.stack: c000000fe63b0000 NIP: c00000000001a1a8 LR: c00000000001a1a4 CTR: c000000000717780 REGS: c000000fe63b3420 TRAP: 0700 Not tainted (4.8.0-rc1-gcc6x-g61e8a0d) MSR: 900000010282b033 <SF,HV,VEC,VSX,EE,FP,ME,IR,DR,RI,LE,TM[E]> CR: 28004222 XER: 20000000 ... NIP [c00000000001a1a8] flush_tmregs_to_thread+0x78/0x80 LR [c00000000001a1a4] flush_tmregs_to_thread+0x74/0x80 Call Trace: flush_tmregs_to_thread+0x74/0x80 (unreliable) vsr_get+0x64/0x1a0 elf_core_dump+0x604/0x1430 do_coredump+0x5fc/0x1200 get_signal+0x398/0x740 do_signal+0x54/0x2b0 do_notify_resume+0x98/0xb0 ret_from_except_lite+0x70/0x74 So fix flush_tmregs_to_thread() to detect the case where it is called on current, and a transaction is active, and in that case flush the TM regs to the thread_struct. This patch also moves flush_tmregs_to_thread() into ptrace.c as it is only called from that file. Fixes: 8d460f6156cd ("powerpc/process: Add the function flush_tmregs_to_thread") Signed-off-by: Cyril Bur <cyrilbur@gmail.com> [mpe: Flesh out change log] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-08-10powerpc/32: Fix csum_partial_copy_generic()Christophe Leroy
Commit 7aef4136566b0 ("powerpc32: rewrite csum_partial_copy_generic() based on copy_tofrom_user()") introduced a bug when destination address is odd and initial csum is not null In that (rare) case the initial csum value has to be rotated one byte as well as the resulting value is This patch also fixes related comments Fixes: 7aef4136566b0 ("powerpc32: rewrite csum_partial_copy_generic() based on copy_tofrom_user()") Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-08-10cxl: Set psl_fir_cntl to production environment valueFrederic Barrat
Switch the setting of psl_fir_cntl from debug to production environment recommended value. It mostly affects the PSL behavior when an error is raised in psl_fir1/2. Tested with cxlflash. Signed-off-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com> Reviewed-by: Uma Krishnan <ukrishn@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>