diff options
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/cgroup/rstat.c | 25 | ||||
| -rw-r--r-- | kernel/sched/ext_idle.c | 37 | ||||
| -rw-r--r-- | kernel/trace/ftrace.c | 13 |
3 files changed, 45 insertions, 30 deletions
diff --git a/kernel/cgroup/rstat.c b/kernel/cgroup/rstat.c index ce4752ab9e09..cbeaa499a96a 100644 --- a/kernel/cgroup/rstat.c +++ b/kernel/cgroup/rstat.c @@ -47,8 +47,20 @@ static spinlock_t *ss_rstat_lock(struct cgroup_subsys *ss) static raw_spinlock_t *ss_rstat_cpu_lock(struct cgroup_subsys *ss, int cpu) { - if (ss) + if (ss) { + /* + * Depending on config, the subsystem per-cpu lock type may be an + * empty struct. In enviromnents where this is the case, allocation + * of this field is not performed in ss_rstat_init(). Avoid a + * cpu-based offset relative to NULL by returning early. When the + * lock type is zero in size, the corresponding lock functions are + * no-ops so passing them NULL is acceptable. + */ + if (sizeof(*ss->rstat_ss_cpu_lock) == 0) + return NULL; + return per_cpu_ptr(ss->rstat_ss_cpu_lock, cpu); + } return per_cpu_ptr(&rstat_base_cpu_lock, cpu); } @@ -510,20 +522,15 @@ int __init ss_rstat_init(struct cgroup_subsys *ss) { int cpu; -#ifdef CONFIG_SMP /* - * On uniprocessor machines, arch_spinlock_t is defined as an empty - * struct. Avoid allocating a size of zero by having this block - * excluded in this case. It's acceptable to leave the subsystem locks - * unitialized since the associated lock functions are no-ops in the - * non-smp case. + * Depending on config, the subsystem per-cpu lock type may be an empty + * struct. Avoid allocating a size of zero in this case. */ - if (ss) { + if (ss && sizeof(*ss->rstat_ss_cpu_lock)) { ss->rstat_ss_cpu_lock = alloc_percpu(raw_spinlock_t); if (!ss->rstat_ss_cpu_lock) return -ENOMEM; } -#endif spin_lock_init(ss_rstat_lock(ss)); for_each_possible_cpu(cpu) diff --git a/kernel/sched/ext_idle.c b/kernel/sched/ext_idle.c index 66da03cc0b33..6d29d3cbc670 100644 --- a/kernel/sched/ext_idle.c +++ b/kernel/sched/ext_idle.c @@ -138,6 +138,7 @@ found: goto retry; } +#ifdef CONFIG_NUMA /* * Tracks nodes that have not yet been visited when searching for an idle * CPU across all available nodes. @@ -186,6 +187,13 @@ static s32 pick_idle_cpu_from_online_nodes(const struct cpumask *cpus_allowed, i return cpu; } +#else +static inline s32 +pick_idle_cpu_from_online_nodes(const struct cpumask *cpus_allowed, int node, u64 flags) +{ + return -EBUSY; +} +#endif /* * Find an idle CPU in the system, starting from @node. @@ -447,11 +455,18 @@ s32 scx_select_cpu_dfl(struct task_struct *p, s32 prev_cpu, u64 wake_flags, const struct cpumask *llc_cpus = NULL, *numa_cpus = NULL; const struct cpumask *allowed = cpus_allowed ?: p->cpus_ptr; int node = scx_cpu_node_if_enabled(prev_cpu); + bool is_prev_allowed; s32 cpu; preempt_disable(); /* + * Check whether @prev_cpu is still within the allowed set. If not, + * we can still try selecting a nearby CPU. + */ + is_prev_allowed = cpumask_test_cpu(prev_cpu, allowed); + + /* * Determine the subset of CPUs usable by @p within @cpus_allowed. */ if (allowed != p->cpus_ptr) { @@ -465,21 +480,6 @@ s32 scx_select_cpu_dfl(struct task_struct *p, s32 prev_cpu, u64 wake_flags, cpu = -EBUSY; goto out_enable; } - - /* - * If @prev_cpu is not in the allowed CPUs, skip topology - * optimizations and try to pick any idle CPU usable by the - * task. - * - * If %SCX_OPS_BUILTIN_IDLE_PER_NODE is enabled, prioritize - * the current node, as it may optimize some waker->wakee - * workloads. - */ - if (!cpumask_test_cpu(prev_cpu, allowed)) { - node = scx_cpu_node_if_enabled(smp_processor_id()); - cpu = scx_pick_idle_cpu(allowed, node, flags); - goto out_enable; - } } /* @@ -525,7 +525,7 @@ s32 scx_select_cpu_dfl(struct task_struct *p, s32 prev_cpu, u64 wake_flags, * then avoid a migration. */ cpu = smp_processor_id(); - if (cpus_share_cache(cpu, prev_cpu) && + if (is_prev_allowed && cpus_share_cache(cpu, prev_cpu) && scx_idle_test_and_clear_cpu(prev_cpu)) { cpu = prev_cpu; goto out_unlock; @@ -562,7 +562,8 @@ s32 scx_select_cpu_dfl(struct task_struct *p, s32 prev_cpu, u64 wake_flags, /* * Keep using @prev_cpu if it's part of a fully idle core. */ - if (cpumask_test_cpu(prev_cpu, idle_cpumask(node)->smt) && + if (is_prev_allowed && + cpumask_test_cpu(prev_cpu, idle_cpumask(node)->smt) && scx_idle_test_and_clear_cpu(prev_cpu)) { cpu = prev_cpu; goto out_unlock; @@ -611,7 +612,7 @@ s32 scx_select_cpu_dfl(struct task_struct *p, s32 prev_cpu, u64 wake_flags, /* * Use @prev_cpu if it's idle. */ - if (scx_idle_test_and_clear_cpu(prev_cpu)) { + if (is_prev_allowed && scx_idle_test_and_clear_cpu(prev_cpu)) { cpu = prev_cpu; goto out_unlock; } diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 1af952cba48d..a7291685902e 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -7438,9 +7438,10 @@ void ftrace_release_mod(struct module *mod) mutex_lock(&ftrace_lock); - if (ftrace_disabled) - goto out_unlock; - + /* + * To avoid the UAF problem after the module is unloaded, the + * 'mod_map' resource needs to be released unconditionally. + */ list_for_each_entry_safe(mod_map, n, &ftrace_mod_maps, list) { if (mod_map->mod == mod) { list_del_rcu(&mod_map->list); @@ -7449,6 +7450,9 @@ void ftrace_release_mod(struct module *mod) } } + if (ftrace_disabled) + goto out_unlock; + /* * Each module has its own ftrace_pages, remove * them from the list. @@ -7627,6 +7631,9 @@ allocate_ftrace_mod_map(struct module *mod, { struct ftrace_mod_map *mod_map; + if (ftrace_disabled) + return NULL; + mod_map = kmalloc(sizeof(*mod_map), GFP_KERNEL); if (!mod_map) return NULL; |