diff options
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/cgroup.c | 2 | ||||
| -rw-r--r-- | kernel/events/core.c | 57 | ||||
| -rw-r--r-- | kernel/sysctl.c | 9 | ||||
| -rw-r--r-- | kernel/trace/ring_buffer.c | 16 | ||||
| -rw-r--r-- | kernel/trace/trace.c | 8 |
5 files changed, 82 insertions, 10 deletions
diff --git a/kernel/cgroup.c b/kernel/cgroup.c index b52f88e44182..25cf44889559 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -2693,7 +2693,7 @@ static int cgroup_procs_write_permission(struct task_struct *task, if (!uid_eq(cred->euid, GLOBAL_ROOT_UID) && !uid_eq(cred->euid, tcred->uid) && !uid_eq(cred->euid, tcred->suid) && - !ns_capable(tcred->user_ns, CAP_SYS_RESOURCE)) + !ns_capable(tcred->user_ns, CAP_SYS_NICE)) ret = -EACCES; if (!ret && cgroup_on_dfl(dst_cgrp)) { diff --git a/kernel/events/core.c b/kernel/events/core.c index 06db8b64129d..95c447e658f7 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -8454,6 +8454,37 @@ static int perf_event_set_clock(struct perf_event *event, clockid_t clk_id) return 0; } +/* + * Variation on perf_event_ctx_lock_nested(), except we take two context + * mutexes. + */ +static struct perf_event_context * +__perf_event_ctx_lock_double(struct perf_event *group_leader, + struct perf_event_context *ctx) +{ + struct perf_event_context *gctx; + +again: + rcu_read_lock(); + gctx = READ_ONCE(group_leader->ctx); + if (!atomic_inc_not_zero(&gctx->refcount)) { + rcu_read_unlock(); + goto again; + } + rcu_read_unlock(); + + mutex_lock_double(&gctx->mutex, &ctx->mutex); + + if (group_leader->ctx != gctx) { + mutex_unlock(&ctx->mutex); + mutex_unlock(&gctx->mutex); + put_ctx(gctx); + goto again; + } + + return gctx; +} + /** * sys_perf_event_open - open a performance event, associate it to a task/cpu * @@ -8707,8 +8738,26 @@ SYSCALL_DEFINE5(perf_event_open, } if (move_group) { - gctx = group_leader->ctx; - mutex_lock_double(&gctx->mutex, &ctx->mutex); + gctx = __perf_event_ctx_lock_double(group_leader, ctx); + + /* + * Check if we raced against another sys_perf_event_open() call + * moving the software group underneath us. + */ + if (!(group_leader->group_flags & PERF_GROUP_SOFTWARE)) { + /* + * If someone moved the group out from under us, check + * if this new event wound up on the same ctx, if so + * its the regular !move_group case, otherwise fail. + */ + if (gctx != ctx) { + err = -EINVAL; + goto err_locked; + } else { + perf_event_ctx_unlock(group_leader, gctx); + move_group = 0; + } + } } else { mutex_lock(&ctx->mutex); } @@ -8803,7 +8852,7 @@ SYSCALL_DEFINE5(perf_event_open, perf_unpin_context(ctx); if (move_group) - mutex_unlock(&gctx->mutex); + perf_event_ctx_unlock(group_leader, gctx); mutex_unlock(&ctx->mutex); if (group_leader) mutex_unlock(&group_leader->group_leader_mutex); @@ -8833,7 +8882,7 @@ SYSCALL_DEFINE5(perf_event_open, err_locked: if (move_group) - mutex_unlock(&gctx->mutex); + perf_event_ctx_unlock(group_leader, gctx); mutex_unlock(&ctx->mutex); /* err_file: */ fput(event_file); diff --git a/kernel/sysctl.c b/kernel/sysctl.c index 8cc5167e4b04..816999804a16 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -65,6 +65,7 @@ #include <linux/sched/sysctl.h> #include <linux/kexec.h> #include <linux/bpf.h> +#include <linux/mount.h> #include <asm/uaccess.h> #include <asm/processor.h> @@ -2077,6 +2078,14 @@ static struct ctl_table fs_table[] = { .mode = 0644, .proc_handler = proc_doulongvec_minmax, }, + { + .procname = "mount-max", + .data = &sysctl_mount_max, + .maxlen = sizeof(unsigned int), + .mode = 0644, + .proc_handler = proc_dointvec_minmax, + .extra1 = &one, + }, { } }; diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index 7d7f99b0db47..1275175b0946 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -3440,11 +3440,23 @@ EXPORT_SYMBOL_GPL(ring_buffer_iter_reset); int ring_buffer_iter_empty(struct ring_buffer_iter *iter) { struct ring_buffer_per_cpu *cpu_buffer; + struct buffer_page *reader; + struct buffer_page *head_page; + struct buffer_page *commit_page; + unsigned commit; cpu_buffer = iter->cpu_buffer; - return iter->head_page == cpu_buffer->commit_page && - iter->head == rb_commit_index(cpu_buffer); + /* Remember, trace recording is off when iterator is in use */ + reader = cpu_buffer->reader_page; + head_page = cpu_buffer->head_page; + commit_page = cpu_buffer->commit_page; + commit = rb_page_commit(commit_page); + + return ((iter->head_page == commit_page && iter->head == commit) || + (iter->head_page == reader && commit_page == head_page && + head_page->read == commit && + iter->head == rb_page_commit(cpu_buffer->reader_page))); } EXPORT_SYMBOL_GPL(ring_buffer_iter_empty); diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index c0c10a335b3b..60d246c4eefa 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -6170,11 +6170,13 @@ ftrace_trace_snapshot_callback(struct ftrace_hash *hash, return ret; out_reg: - ret = register_ftrace_function_probe(glob, ops, count); + ret = alloc_snapshot(&global_trace); + if (ret < 0) + goto out; - if (ret >= 0) - alloc_snapshot(&global_trace); + ret = register_ftrace_function_probe(glob, ops, count); + out: return ret < 0 ? ret : 0; } |