linux/kernel/cpu.c, branch v5.3

Merge branch 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2019-07-08T17:39:56Z

Pull SMP/hotplug updates from Thomas Gleixner: "A small set of updates for SMP and CPU hotplug: - Abort disabling secondary CPUs in the freezer when a wakeup is pending instead of evaluating it only after all CPUs have been offlined. - Remove the shared annotation for the strict per CPU cfd_data in the smp function call core code. - Remove the return values of smp_call_function() and on_each_cpu() as they are unconditionally 0. Fixup the few callers which actually bothered to check the return value" * 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: smp: Remove smp_call_function() and on_each_cpu() return values smp: Do not mark call_function_data as shared cpu/hotplug: Abort disabling secondary CPUs if wakeup is pending cpu/hotplug: Fix notify_cpu_starting() reference in bringup_wait_for_ap()

cpu/hotplug: Fix out-of-bounds read when setting fail state

2019-06-27T07:34:04Z

Setting invalid value to /sys/devices/system/cpu/cpuX/hotplug/fail can control `struct cpuhp_step *sp` address, results in the following global-out-of-bounds read. Reproducer: # echo -2 > /sys/devices/system/cpu/cpu0/hotplug/fail KASAN report: BUG: KASAN: global-out-of-bounds in write_cpuhp_fail+0x2cd/0x2e0 Read of size 8 at addr ffffffff89734438 by task bash/1941 CPU: 0 PID: 1941 Comm: bash Not tainted 5.2.0-rc6+ #31 Call Trace: write_cpuhp_fail+0x2cd/0x2e0 dev_attr_store+0x58/0x80 sysfs_kf_write+0x13d/0x1a0 kernfs_fop_write+0x2bc/0x460 vfs_write+0x1e1/0x560 ksys_write+0x126/0x250 do_syscall_64+0xc1/0x390 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x7f05e4f4c970 The buggy address belongs to the variable: cpu_hotplug_lock+0x98/0xa0 Memory state around the buggy address: ffffffff89734300: fa fa fa fa 00 00 00 00 00 00 00 00 00 00 00 00 ffffffff89734380: fa fa fa fa 00 00 00 00 00 00 00 00 00 00 00 00 >ffffffff89734400: 00 00 00 00 fa fa fa fa 00 00 00 00 fa fa fa fa ^ ffffffff89734480: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffffffff89734500: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 Add a sanity check for the value written from user space. Fixes: 1db49484f21ed ("smp/hotplug: Hotplug state fail injection") Signed-off-by: Eiichi Tsukata Signed-off-by: Thomas Gleixner Cc: peterz@infradead.org Link: https://lkml.kernel.org/r/20190627024732.31672-1-devel@etsukata.com

cpu/speculation: Warn on unsupported mitigations= parameter

2019-06-26T14:56:21Z

Currently, if the user specifies an unsupported mitigation strategy on the kernel command line, it will be ignored silently. The code will fall back to the default strategy, possibly leaving the system more vulnerable than expected. This may happen due to e.g. a simple typo, or, for a stable kernel release, because not all mitigation strategies have been backported. Inform the user by printing a message. Fixes: 98af8452945c5565 ("cpu/speculation: Add 'mitigations=' cmdline option") Signed-off-by: Geert Uytterhoeven Signed-off-by: Thomas Gleixner Acked-by: Josh Poimboeuf Cc: Peter Zijlstra Cc: Jiri Kosina Cc: Greg Kroah-Hartman Cc: Ben Hutchings Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20190516070935.22546-1-geert@linux-m68k.org

cpu/hotplug: Abort disabling secondary CPUs if wakeup is pending

2019-06-12T09:03:05Z

When "deep" suspend is enabled, all CPUs except the primary CPU are frozen via CPU hotplug one by one. After all secondary CPUs are unplugged the wakeup pending condition is evaluated and if pending the suspend operation is aborted and the secondary CPUs are brought up again. CPU hotplug is a slow operation, so it makes sense to check for wakeup pending in the freezer loop before bringing down the next CPU. This improves the system suspend abort latency significantly. [ tglx: Massaged changelog and improved printk message ] Signed-off-by: Pavankumar Kondeti Signed-off-by: Thomas Gleixner Cc: "Rafael J. Wysocki" Cc: Len Brown Cc: Pavel Machek Cc: Josh Poimboeuf Cc: Peter Zijlstra Cc: Konrad Rzeszutek Wilk Cc: iri Kosina Cc: Mukesh Ojha Cc: linux-pm@vger.kernel.org Link: https://lkml.kernel.org/r/1559536263-16472-1-git-send-email-pkondeti@codeaurora.org

x86/power: Fix 'nosmt' vs hibernation triple fault during resume

2019-06-03T10:02:03Z

As explained in 0cc3cd21657b ("cpu/hotplug: Boot HT siblings at least once") we always, no matter what, have to bring up x86 HT siblings during boot at least once in order to avoid first MCE bringing the system to its knees. That means that whenever 'nosmt' is supplied on the kernel command-line, all the HT siblings are as a result sitting in mwait or cpudile after going through the online-offline cycle at least once. This causes a serious issue though when a kernel, which saw 'nosmt' on its commandline, is going to perform resume from hibernation: if the resume from the hibernated image is successful, cr3 is flipped in order to point to the address space of the kernel that is being resumed, which in turn means that all the HT siblings are all of a sudden mwaiting on address which is no longer valid. That results in triple fault shortly after cr3 is switched, and machine reboots. Fix this by always waking up all the SMT siblings before initiating the 'restore from hibernation' process; this guarantees that all the HT siblings will be properly carried over to the resumed kernel waiting in resume_play_dead(), and acted upon accordingly afterwards, based on the target kernel configuration. Symmetricaly, the resumed kernel has to push the SMT siblings to mwait again in case it has SMT disabled; this means it has to online all the siblings when resuming (so that they come out of hlt) and offline them again to let them reach mwait. Cc: 4.19+ # v4.19+ Debugged-by: Thomas Gleixner Fixes: 0cc3cd21657b ("cpu/hotplug: Boot HT siblings at least once") Signed-off-by: Jiri Kosina Acked-by: Pavel Machek Reviewed-by: Thomas Gleixner Reviewed-by: Josh Poimboeuf Signed-off-by: Rafael J. Wysocki

cpu/hotplug: Fix notify_cpu_starting() reference in bringup_wait_for_ap()

2019-05-28T19:59:03Z

bringup_wait_for_ap() comment references cpu_notify_starting(), but the function is actually called notify_cpu_starting(). Fix that. Signed-off-by: Jiri Kosina Signed-off-by: Thomas Gleixner Cc: Josh Poimboeuf Cc: Peter Zijlstra Link: https://lkml.kernel.org/r/nycvar.YFH.7.76.1905282128100.1962@cbobk.fhfr.pm

Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2019-05-06T21:50:46Z

Pull timer updates from Ingo Molnar: "This cycle had the following changes: - Timer tracing improvements (Anna-Maria Gleixner) - Continued tasklet reduction work: remove the hrtimer_tasklet (Thomas Gleixner) - Fix CPU hotplug remove race in the tick-broadcast mask handling code (Thomas Gleixner) - Force upper bound for setting CLOCK_REALTIME, to fix ABI inconsistencies with handling values that are close to the maximum supported and the vagueness of when uptime related wraparound might occur. Make the consistent maximum the year 2232 across all relevant ABIs and APIs. (Thomas Gleixner) - various cleanups and smaller fixes" * 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: tick: Fix typos in comments tick/broadcast: Fix warning about undefined tick_broadcast_oneshot_offline() timekeeping: Force upper bound for setting CLOCK_REALTIME timer/trace: Improve timer tracing timer/trace: Replace deprecated vsprintf pointer extension %pf by %ps timer: Move trace point to get proper index tick/sched: Update tick_sched struct documentation tick: Remove outgoing CPU from broadcast masks timekeeping: Consistently use unsigned int for seqcount snapshot softirq: Remove tasklet_hrtimer xfrm: Replace hrtimer tasklet with softirq hrtimer mac80211_hwsim: Replace hrtimer tasklet with softirq hrtimer

Merge branch 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2019-05-06T21:44:49Z

Pull CPU hotplug updates from Ingo Molnar: "Two changes in this cycle: - Make the /sys/devices/system/cpu/smt/* files available on all arches, so user space has a consistent way to detect whether SMT is enabled. - Sparse annotation fix" * 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: smpboot: Place the __percpu annotation correctly cpu/hotplug: Create SMT sysfs interface for all arches

Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2019-05-06T21:31:50Z

Pull scheduler updates from Ingo Molnar: "The main changes in this cycle were: - Make nohz housekeeping processing more permissive and less intrusive to isolated CPUs - Decouple CPU-bound workqueue acconting from the scheduler and move it into the workqueue code. - Optimize topology building - Better handle quota and period overflows - Add more RCU annotations - Comment updates, misc cleanups" * 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (25 commits) nohz_full: Allow the boot CPU to be nohz_full sched/isolation: Require a present CPU in housekeeping mask kernel/cpu: Allow non-zero CPU to be primary for suspend / kexec freeze power/suspend: Add function to disable secondaries for suspend sched/core: Allow the remote scheduler tick to be started on CPU0 sched/nohz: Run NOHZ idle load balancer on HK_FLAG_MISC CPUs sched/debug: Fix spelling mistake "logaritmic" -> "logarithmic" sched/topology: Update init_sched_domains() comment cgroup/cpuset: Update stale generate_sched_domains() comments sched/core: Check quota and period overflow at usec to nsec conversion sched/core: Handle overflow in cpu_shares_write_u64 sched/rt: Check integer overflow at usec to nsec conversion sched/core: Fix typo in comment sched/core: Make some functions static sched/core: Unify p->on_rq updates sched/core: Remove ttwu_activate() sched/core, workqueues: Distangle worker accounting from rq lock sched/fair: Remove unneeded prototype of capacity_of() sched/topology: Skip duplicate group rewrites in build_sched_groups() sched/topology: Fix build_sched_groups() comment ...

Merge branch 'core-speculation-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2019-05-06T20:01:16Z

Pull speculation mitigation update from Ingo Molnar: "This adds the "mitigations=" bootline option, which offers a cross-arch set of options that will work on x86, PowerPC and s390 that will map to the arch specific option internally" * 'core-speculation-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: s390/speculation: Support 'mitigations=' cmdline option powerpc/speculation: Support 'mitigations=' cmdline option x86/speculation: Support 'mitigations=' cmdline option cpu/speculation: Add 'mitigations=' cmdline option