diff options
author | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2023-01-24 21:12:49 +0100 |
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committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2023-01-24 21:12:49 +0100 |
commit | 8ef0ca4a177d2dbe6680fb4388173897900a4ed1 (patch) | |
tree | c67b1e358f50bce724b61b43be885f90a229fad1 /kernel/sched/core.c | |
parent | 763bd29fd3d1742153f6c6847ca3b3560e7ca957 (diff) | |
parent | a2c81dc59d41e92362ab7d41d0c15471ea50637d (diff) |
Merge back other thermal control material for 6.3.
* thermal: (734 commits)
thermal: core: call put_device() only after device_register() fails
Linux 6.2-rc4
kbuild: Fix CFI hash randomization with KASAN
firmware: coreboot: Check size of table entry and use flex-array
kallsyms: Fix scheduling with interrupts disabled in self-test
ata: pata_cs5535: Don't build on UML
lockref: stop doing cpu_relax in the cmpxchg loop
x86/pci: Treat EfiMemoryMappedIO as reservation of ECAM space
efi: tpm: Avoid READ_ONCE() for accessing the event log
io_uring: lock overflowing for IOPOLL
ALSA: pcm: Move rwsem lock inside snd_ctl_elem_read to prevent UAF
iommu/mediatek-v1: Fix an error handling path in mtk_iommu_v1_probe()
iommu/iova: Fix alloc iova overflows issue
iommu: Fix refcount leak in iommu_device_claim_dma_owner
iommu/arm-smmu-v3: Don't unregister on shutdown
iommu/arm-smmu: Don't unregister on shutdown
iommu/arm-smmu: Report IOMMU_CAP_CACHE_COHERENCY even betterer
platform/x86: thinkpad_acpi: Fix profile mode display in AMT mode
ALSA: usb-audio: Fix possible NULL pointer dereference in snd_usb_pcm_has_fixed_rate()
platform/x86: int3472/discrete: Ensure the clk/power enable pins are in output mode
...
Diffstat (limited to 'kernel/sched/core.c')
-rw-r--r-- | kernel/sched/core.c | 69 |
1 files changed, 60 insertions, 9 deletions
diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 25b582b6ee5f..bb1ee6d7bdde 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -2604,27 +2604,71 @@ void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask) .user_mask = NULL, .flags = SCA_USER, /* clear the user requested mask */ }; + union cpumask_rcuhead { + cpumask_t cpumask; + struct rcu_head rcu; + }; __do_set_cpus_allowed(p, &ac); - kfree(ac.user_mask); + + /* + * Because this is called with p->pi_lock held, it is not possible + * to use kfree() here (when PREEMPT_RT=y), therefore punt to using + * kfree_rcu(). + */ + kfree_rcu((union cpumask_rcuhead *)ac.user_mask, rcu); +} + +static cpumask_t *alloc_user_cpus_ptr(int node) +{ + /* + * See do_set_cpus_allowed() above for the rcu_head usage. + */ + int size = max_t(int, cpumask_size(), sizeof(struct rcu_head)); + + return kmalloc_node(size, GFP_KERNEL, node); } int dup_user_cpus_ptr(struct task_struct *dst, struct task_struct *src, int node) { + cpumask_t *user_mask; unsigned long flags; - if (!src->user_cpus_ptr) + /* + * Always clear dst->user_cpus_ptr first as their user_cpus_ptr's + * may differ by now due to racing. + */ + dst->user_cpus_ptr = NULL; + + /* + * This check is racy and losing the race is a valid situation. + * It is not worth the extra overhead of taking the pi_lock on + * every fork/clone. + */ + if (data_race(!src->user_cpus_ptr)) return 0; - dst->user_cpus_ptr = kmalloc_node(cpumask_size(), GFP_KERNEL, node); - if (!dst->user_cpus_ptr) + user_mask = alloc_user_cpus_ptr(node); + if (!user_mask) return -ENOMEM; - /* Use pi_lock to protect content of user_cpus_ptr */ + /* + * Use pi_lock to protect content of user_cpus_ptr + * + * Though unlikely, user_cpus_ptr can be reset to NULL by a concurrent + * do_set_cpus_allowed(). + */ raw_spin_lock_irqsave(&src->pi_lock, flags); - cpumask_copy(dst->user_cpus_ptr, src->user_cpus_ptr); + if (src->user_cpus_ptr) { + swap(dst->user_cpus_ptr, user_mask); + cpumask_copy(dst->user_cpus_ptr, src->user_cpus_ptr); + } raw_spin_unlock_irqrestore(&src->pi_lock, flags); + + if (unlikely(user_mask)) + kfree(user_mask); + return 0; } @@ -3581,6 +3625,11 @@ static inline bool rq_has_pinned_tasks(struct rq *rq) return false; } +static inline cpumask_t *alloc_user_cpus_ptr(int node) +{ + return NULL; +} + #endif /* !CONFIG_SMP */ static void @@ -5504,7 +5553,9 @@ void scheduler_tick(void) unsigned long thermal_pressure; u64 resched_latency; - arch_scale_freq_tick(); + if (housekeeping_cpu(cpu, HK_TYPE_TICK)) + arch_scale_freq_tick(); + sched_clock_tick(); rq_lock(rq, &rf); @@ -8239,8 +8290,8 @@ long sched_setaffinity(pid_t pid, const struct cpumask *in_mask) if (retval) goto out_put_task; - user_mask = kmalloc(cpumask_size(), GFP_KERNEL); - if (!user_mask) { + user_mask = alloc_user_cpus_ptr(NUMA_NO_NODE); + if (IS_ENABLED(CONFIG_SMP) && !user_mask) { retval = -ENOMEM; goto out_put_task; } |