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author | Linus Torvalds <torvalds@linux-foundation.org> | 2018-05-13 10:53:08 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2018-05-13 10:53:08 -0700 |
commit | 66e1c94db3cd4e094de66a6be68c3ab6d17e0c52 (patch) | |
tree | 920eecb13e08704407ce3aa9739699366b3ef130 /kernel/sched | |
parent | 86a4ac433b927a610c09aa6cfb1926d94a6b37b7 (diff) | |
parent | e0f6d1a526b6adfa9ca3b336b83ece0eed345033 (diff) | |
download | op-kernel-dev-66e1c94db3cd4e094de66a6be68c3ab6d17e0c52.zip op-kernel-dev-66e1c94db3cd4e094de66a6be68c3ab6d17e0c52.tar.gz |
Merge branch 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86/pti updates from Thomas Gleixner:
"A mixed bag of fixes and updates for the ghosts which are hunting us.
The scheduler fixes have been pulled into that branch to avoid
conflicts.
- A set of fixes to address a khread_parkme() race which caused lost
wakeups and loss of state.
- A deadlock fix for stop_machine() solved by moving the wakeups
outside of the stopper_lock held region.
- A set of Spectre V1 array access restrictions. The possible
problematic spots were discuvered by Dan Carpenters new checks in
smatch.
- Removal of an unused file which was forgotten when the rest of that
functionality was removed"
* 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/vdso: Remove unused file
perf/x86/cstate: Fix possible Spectre-v1 indexing for pkg_msr
perf/x86/msr: Fix possible Spectre-v1 indexing in the MSR driver
perf/x86: Fix possible Spectre-v1 indexing for x86_pmu::event_map()
perf/x86: Fix possible Spectre-v1 indexing for hw_perf_event cache_*
perf/core: Fix possible Spectre-v1 indexing for ->aux_pages[]
sched/autogroup: Fix possible Spectre-v1 indexing for sched_prio_to_weight[]
sched/core: Fix possible Spectre-v1 indexing for sched_prio_to_weight[]
sched/core: Introduce set_special_state()
kthread, sched/wait: Fix kthread_parkme() completion issue
kthread, sched/wait: Fix kthread_parkme() wait-loop
sched/fair: Fix the update of blocked load when newly idle
stop_machine, sched: Fix migrate_swap() vs. active_balance() deadlock
Diffstat (limited to 'kernel/sched')
-rw-r--r-- | kernel/sched/autogroup.c | 7 | ||||
-rw-r--r-- | kernel/sched/core.c | 56 | ||||
-rw-r--r-- | kernel/sched/fair.c | 2 |
3 files changed, 34 insertions, 31 deletions
diff --git a/kernel/sched/autogroup.c b/kernel/sched/autogroup.c index 6be6c57..2d4ff53 100644 --- a/kernel/sched/autogroup.c +++ b/kernel/sched/autogroup.c @@ -2,6 +2,7 @@ /* * Auto-group scheduling implementation: */ +#include <linux/nospec.h> #include "sched.h" unsigned int __read_mostly sysctl_sched_autogroup_enabled = 1; @@ -209,7 +210,7 @@ int proc_sched_autogroup_set_nice(struct task_struct *p, int nice) static unsigned long next = INITIAL_JIFFIES; struct autogroup *ag; unsigned long shares; - int err; + int err, idx; if (nice < MIN_NICE || nice > MAX_NICE) return -EINVAL; @@ -227,7 +228,9 @@ int proc_sched_autogroup_set_nice(struct task_struct *p, int nice) next = HZ / 10 + jiffies; ag = autogroup_task_get(p); - shares = scale_load(sched_prio_to_weight[nice + 20]); + + idx = array_index_nospec(nice + 20, 40); + shares = scale_load(sched_prio_to_weight[idx]); down_write(&ag->lock); err = sched_group_set_shares(ag->tg, shares); diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 5e10aae..092f7c4 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -7,6 +7,9 @@ */ #include "sched.h" +#include <linux/kthread.h> +#include <linux/nospec.h> + #include <asm/switch_to.h> #include <asm/tlb.h> @@ -2718,20 +2721,28 @@ static struct rq *finish_task_switch(struct task_struct *prev) membarrier_mm_sync_core_before_usermode(mm); mmdrop(mm); } - if (unlikely(prev_state == TASK_DEAD)) { - if (prev->sched_class->task_dead) - prev->sched_class->task_dead(prev); + if (unlikely(prev_state & (TASK_DEAD|TASK_PARKED))) { + switch (prev_state) { + case TASK_DEAD: + if (prev->sched_class->task_dead) + prev->sched_class->task_dead(prev); - /* - * Remove function-return probe instances associated with this - * task and put them back on the free list. - */ - kprobe_flush_task(prev); + /* + * Remove function-return probe instances associated with this + * task and put them back on the free list. + */ + kprobe_flush_task(prev); + + /* Task is done with its stack. */ + put_task_stack(prev); - /* Task is done with its stack. */ - put_task_stack(prev); + put_task_struct(prev); + break; - put_task_struct(prev); + case TASK_PARKED: + kthread_park_complete(prev); + break; + } } tick_nohz_task_switch(); @@ -3498,23 +3509,8 @@ static void __sched notrace __schedule(bool preempt) void __noreturn do_task_dead(void) { - /* - * The setting of TASK_RUNNING by try_to_wake_up() may be delayed - * when the following two conditions become true. - * - There is race condition of mmap_sem (It is acquired by - * exit_mm()), and - * - SMI occurs before setting TASK_RUNINNG. - * (or hypervisor of virtual machine switches to other guest) - * As a result, we may become TASK_RUNNING after becoming TASK_DEAD - * - * To avoid it, we have to wait for releasing tsk->pi_lock which - * is held by try_to_wake_up() - */ - raw_spin_lock_irq(¤t->pi_lock); - raw_spin_unlock_irq(¤t->pi_lock); - /* Causes final put_task_struct in finish_task_switch(): */ - __set_current_state(TASK_DEAD); + set_special_state(TASK_DEAD); /* Tell freezer to ignore us: */ current->flags |= PF_NOFREEZE; @@ -6928,11 +6924,15 @@ static int cpu_weight_nice_write_s64(struct cgroup_subsys_state *css, struct cftype *cft, s64 nice) { unsigned long weight; + int idx; if (nice < MIN_NICE || nice > MAX_NICE) return -ERANGE; - weight = sched_prio_to_weight[NICE_TO_PRIO(nice) - MAX_RT_PRIO]; + idx = NICE_TO_PRIO(nice) - MAX_RT_PRIO; + idx = array_index_nospec(idx, 40); + weight = sched_prio_to_weight[idx]; + return sched_group_set_shares(css_tg(css), scale_load(weight)); } #endif diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index f43627c..79f574d 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -9792,6 +9792,7 @@ static int idle_balance(struct rq *this_rq, struct rq_flags *rf) if (curr_cost > this_rq->max_idle_balance_cost) this_rq->max_idle_balance_cost = curr_cost; +out: /* * While browsing the domains, we released the rq lock, a task could * have been enqueued in the meantime. Since we're not going idle, @@ -9800,7 +9801,6 @@ static int idle_balance(struct rq *this_rq, struct rq_flags *rf) if (this_rq->cfs.h_nr_running && !pulled_task) pulled_task = 1; -out: /* Move the next balance forward */ if (time_after(this_rq->next_balance, next_balance)) this_rq->next_balance = next_balance; |