diff options
Diffstat (limited to 'kernel/events/core.c')
-rw-r--r-- | kernel/events/core.c | 142 |
1 files changed, 73 insertions, 69 deletions
diff --git a/kernel/events/core.c b/kernel/events/core.c index 2ba8904..dbccf83 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -372,6 +372,8 @@ void perf_cgroup_switch(struct task_struct *task, int mode) list_for_each_entry_rcu(pmu, &pmus, entry) { cpuctx = this_cpu_ptr(pmu->pmu_cpu_context); + if (cpuctx->unique_pmu != pmu) + continue; /* ensure we process each cpuctx once */ /* * perf_cgroup_events says at least one @@ -395,9 +397,10 @@ void perf_cgroup_switch(struct task_struct *task, int mode) if (mode & PERF_CGROUP_SWIN) { WARN_ON_ONCE(cpuctx->cgrp); - /* set cgrp before ctxsw in to - * allow event_filter_match() to not - * have to pass task around + /* + * set cgrp before ctxsw in to allow + * event_filter_match() to not have to pass + * task around */ cpuctx->cgrp = perf_cgroup_from_task(task); cpu_ctx_sched_in(cpuctx, EVENT_ALL, task); @@ -468,14 +471,13 @@ static inline int perf_cgroup_connect(int fd, struct perf_event *event, { struct perf_cgroup *cgrp; struct cgroup_subsys_state *css; - struct file *file; - int ret = 0, fput_needed; + struct fd f = fdget(fd); + int ret = 0; - file = fget_light(fd, &fput_needed); - if (!file) + if (!f.file) return -EBADF; - css = cgroup_css_from_dir(file, perf_subsys_id); + css = cgroup_css_from_dir(f.file, perf_subsys_id); if (IS_ERR(css)) { ret = PTR_ERR(css); goto out; @@ -501,7 +503,7 @@ static inline int perf_cgroup_connect(int fd, struct perf_event *event, ret = -EINVAL; } out: - fput_light(file, fput_needed); + fdput(f); return ret; } @@ -1254,7 +1256,7 @@ retry: /* * Cross CPU call to disable a performance event */ -static int __perf_event_disable(void *info) +int __perf_event_disable(void *info) { struct perf_event *event = info; struct perf_event_context *ctx = event->ctx; @@ -2936,12 +2938,12 @@ EXPORT_SYMBOL_GPL(perf_event_release_kernel); /* * Called when the last reference to the file is gone. */ -static int perf_release(struct inode *inode, struct file *file) +static void put_event(struct perf_event *event) { - struct perf_event *event = file->private_data; struct task_struct *owner; - file->private_data = NULL; + if (!atomic_long_dec_and_test(&event->refcount)) + return; rcu_read_lock(); owner = ACCESS_ONCE(event->owner); @@ -2976,7 +2978,13 @@ static int perf_release(struct inode *inode, struct file *file) put_task_struct(owner); } - return perf_event_release_kernel(event); + perf_event_release_kernel(event); +} + +static int perf_release(struct inode *inode, struct file *file) +{ + put_event(file->private_data); + return 0; } u64 perf_event_read_value(struct perf_event *event, u64 *enabled, u64 *running) @@ -3228,21 +3236,18 @@ unlock: static const struct file_operations perf_fops; -static struct perf_event *perf_fget_light(int fd, int *fput_needed) +static inline int perf_fget_light(int fd, struct fd *p) { - struct file *file; - - file = fget_light(fd, fput_needed); - if (!file) - return ERR_PTR(-EBADF); + struct fd f = fdget(fd); + if (!f.file) + return -EBADF; - if (file->f_op != &perf_fops) { - fput_light(file, *fput_needed); - *fput_needed = 0; - return ERR_PTR(-EBADF); + if (f.file->f_op != &perf_fops) { + fdput(f); + return -EBADF; } - - return file->private_data; + *p = f; + return 0; } static int perf_event_set_output(struct perf_event *event, @@ -3274,20 +3279,19 @@ static long perf_ioctl(struct file *file, unsigned int cmd, unsigned long arg) case PERF_EVENT_IOC_SET_OUTPUT: { - struct perf_event *output_event = NULL; - int fput_needed = 0; int ret; - if (arg != -1) { - output_event = perf_fget_light(arg, &fput_needed); - if (IS_ERR(output_event)) - return PTR_ERR(output_event); + struct perf_event *output_event; + struct fd output; + ret = perf_fget_light(arg, &output); + if (ret) + return ret; + output_event = output.file->private_data; + ret = perf_event_set_output(event, output_event); + fdput(output); + } else { + ret = perf_event_set_output(event, NULL); } - - ret = perf_event_set_output(event, output_event); - if (output_event) - fput_light(output_event->filp, fput_needed); - return ret; } @@ -3670,7 +3674,7 @@ unlock: atomic_inc(&event->mmap_count); mutex_unlock(&event->mmap_mutex); - vma->vm_flags |= VM_RESERVED; + vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP; vma->vm_ops = &perf_mmap_vmops; return ret; @@ -4411,7 +4415,7 @@ static void perf_event_task_event(struct perf_task_event *task_event) rcu_read_lock(); list_for_each_entry_rcu(pmu, &pmus, entry) { cpuctx = get_cpu_ptr(pmu->pmu_cpu_context); - if (cpuctx->active_pmu != pmu) + if (cpuctx->unique_pmu != pmu) goto next; perf_event_task_ctx(&cpuctx->ctx, task_event); @@ -4557,7 +4561,7 @@ static void perf_event_comm_event(struct perf_comm_event *comm_event) rcu_read_lock(); list_for_each_entry_rcu(pmu, &pmus, entry) { cpuctx = get_cpu_ptr(pmu->pmu_cpu_context); - if (cpuctx->active_pmu != pmu) + if (cpuctx->unique_pmu != pmu) goto next; perf_event_comm_ctx(&cpuctx->ctx, comm_event); @@ -4753,7 +4757,7 @@ got_name: rcu_read_lock(); list_for_each_entry_rcu(pmu, &pmus, entry) { cpuctx = get_cpu_ptr(pmu->pmu_cpu_context); - if (cpuctx->active_pmu != pmu) + if (cpuctx->unique_pmu != pmu) goto next; perf_event_mmap_ctx(&cpuctx->ctx, mmap_event, vma->vm_flags & VM_EXEC); @@ -5854,8 +5858,8 @@ static void update_pmu_context(struct pmu *pmu, struct pmu *old_pmu) cpuctx = per_cpu_ptr(pmu->pmu_cpu_context, cpu); - if (cpuctx->active_pmu == old_pmu) - cpuctx->active_pmu = pmu; + if (cpuctx->unique_pmu == old_pmu) + cpuctx->unique_pmu = pmu; } } @@ -5990,7 +5994,7 @@ skip_type: cpuctx->ctx.pmu = pmu; cpuctx->jiffies_interval = 1; INIT_LIST_HEAD(&cpuctx->rotation_list); - cpuctx->active_pmu = pmu; + cpuctx->unique_pmu = pmu; } got_cpu_context: @@ -6142,6 +6146,7 @@ perf_event_alloc(struct perf_event_attr *attr, int cpu, mutex_init(&event->mmap_mutex); + atomic_long_set(&event->refcount, 1); event->cpu = cpu; event->attr = *attr; event->group_leader = group_leader; @@ -6434,12 +6439,11 @@ SYSCALL_DEFINE5(perf_event_open, struct perf_event_attr attr; struct perf_event_context *ctx; struct file *event_file = NULL; - struct file *group_file = NULL; + struct fd group = {NULL, 0}; struct task_struct *task = NULL; struct pmu *pmu; int event_fd; int move_group = 0; - int fput_needed = 0; int err; /* for future expandability... */ @@ -6469,17 +6473,15 @@ SYSCALL_DEFINE5(perf_event_open, if ((flags & PERF_FLAG_PID_CGROUP) && (pid == -1 || cpu == -1)) return -EINVAL; - event_fd = get_unused_fd_flags(O_RDWR); + event_fd = get_unused_fd(); if (event_fd < 0) return event_fd; if (group_fd != -1) { - group_leader = perf_fget_light(group_fd, &fput_needed); - if (IS_ERR(group_leader)) { - err = PTR_ERR(group_leader); + err = perf_fget_light(group_fd, &group); + if (err) goto err_fd; - } - group_file = group_leader->filp; + group_leader = group.file->private_data; if (flags & PERF_FLAG_FD_OUTPUT) output_event = group_leader; if (flags & PERF_FLAG_FD_NO_GROUP) @@ -6616,7 +6618,6 @@ SYSCALL_DEFINE5(perf_event_open, put_ctx(gctx); } - event->filp = event_file; WARN_ON_ONCE(ctx->parent_ctx); mutex_lock(&ctx->mutex); @@ -6656,7 +6657,7 @@ SYSCALL_DEFINE5(perf_event_open, * of the group leader will find the pointer to itself in * perf_group_detach(). */ - fput_light(group_file, fput_needed); + fdput(group); fd_install(event_fd, event_file); return event_fd; @@ -6670,7 +6671,7 @@ err_task: if (task) put_task_struct(task); err_group_fd: - fput_light(group_file, fput_needed); + fdput(group); err_fd: put_unused_fd(event_fd); return err; @@ -6710,7 +6711,6 @@ perf_event_create_kernel_counter(struct perf_event_attr *attr, int cpu, goto err_free; } - event->filp = NULL; WARN_ON_ONCE(ctx->parent_ctx); mutex_lock(&ctx->mutex); perf_install_in_context(ctx, event, cpu); @@ -6792,7 +6792,7 @@ static void sync_child_event(struct perf_event *child_event, * Release the parent event, if this was the last * reference to it. */ - fput(parent_event->filp); + put_event(parent_event); } static void @@ -6868,9 +6868,8 @@ static void perf_event_exit_task_context(struct task_struct *child, int ctxn) * * __perf_event_exit_task() * sync_child_event() - * fput(parent_event->filp) - * perf_release() - * mutex_lock(&ctx->mutex) + * put_event() + * mutex_lock(&ctx->mutex) * * But since its the parent context it won't be the same instance. */ @@ -6938,7 +6937,7 @@ static void perf_free_event(struct perf_event *event, list_del_init(&event->child_list); mutex_unlock(&parent->child_mutex); - fput(parent->filp); + put_event(parent); perf_group_detach(event); list_del_event(event, ctx); @@ -7018,6 +7017,12 @@ inherit_event(struct perf_event *parent_event, NULL, NULL); if (IS_ERR(child_event)) return child_event; + + if (!atomic_long_inc_not_zero(&parent_event->refcount)) { + free_event(child_event); + return NULL; + } + get_ctx(child_ctx); /* @@ -7059,14 +7064,6 @@ inherit_event(struct perf_event *parent_event, raw_spin_unlock_irqrestore(&child_ctx->lock, flags); /* - * Get a reference to the parent filp - we will fput it - * when the child event exits. This is safe to do because - * we are in the parent and we know that the filp still - * exists and has a nonzero count: - */ - atomic_long_inc(&parent_event->filp->f_count); - - /* * Link this into the parent event's child list */ WARN_ON_ONCE(parent_event->ctx->parent_ctx); @@ -7499,5 +7496,12 @@ struct cgroup_subsys perf_subsys = { .destroy = perf_cgroup_destroy, .exit = perf_cgroup_exit, .attach = perf_cgroup_attach, + + /* + * perf_event cgroup doesn't handle nesting correctly. + * ctx->nr_cgroups adjustments should be propagated through the + * cgroup hierarchy. Fix it and remove the following. + */ + .broken_hierarchy = true, }; #endif /* CONFIG_CGROUP_PERF */ |