diff options
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/bpf/syscall.c | 57 | ||||
| -rw-r--r-- | kernel/sysctl.c | 36 |
2 files changed, 92 insertions, 1 deletions
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index c75b2dd2459c..4f34eecec9ce 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -3872,6 +3872,60 @@ static int bpf_link_get_fd_by_id(const union bpf_attr *attr) return fd; } +DEFINE_MUTEX(bpf_stats_enabled_mutex); + +static int bpf_stats_release(struct inode *inode, struct file *file) +{ + mutex_lock(&bpf_stats_enabled_mutex); + static_key_slow_dec(&bpf_stats_enabled_key.key); + mutex_unlock(&bpf_stats_enabled_mutex); + return 0; +} + +static const struct file_operations bpf_stats_fops = { + .release = bpf_stats_release, +}; + +static int bpf_enable_runtime_stats(void) +{ + int fd; + + mutex_lock(&bpf_stats_enabled_mutex); + + /* Set a very high limit to avoid overflow */ + if (static_key_count(&bpf_stats_enabled_key.key) > INT_MAX / 2) { + mutex_unlock(&bpf_stats_enabled_mutex); + return -EBUSY; + } + + fd = anon_inode_getfd("bpf-stats", &bpf_stats_fops, NULL, O_CLOEXEC); + if (fd >= 0) + static_key_slow_inc(&bpf_stats_enabled_key.key); + + mutex_unlock(&bpf_stats_enabled_mutex); + return fd; +} + +#define BPF_ENABLE_STATS_LAST_FIELD enable_stats.type + +static int bpf_enable_stats(union bpf_attr *attr) +{ + + if (CHECK_ATTR(BPF_ENABLE_STATS)) + return -EINVAL; + + if (!capable(CAP_SYS_ADMIN)) + return -EPERM; + + switch (attr->enable_stats.type) { + case BPF_STATS_RUN_TIME: + return bpf_enable_runtime_stats(); + default: + break; + } + return -EINVAL; +} + SYSCALL_DEFINE3(bpf, int, cmd, union bpf_attr __user *, uattr, unsigned int, size) { union bpf_attr attr; @@ -3996,6 +4050,9 @@ SYSCALL_DEFINE3(bpf, int, cmd, union bpf_attr __user *, uattr, unsigned int, siz err = bpf_obj_get_next_id(&attr, uattr, &link_idr, &link_idr_lock); break; + case BPF_ENABLE_STATS: + err = bpf_enable_stats(&attr); + break; default: err = -EINVAL; break; diff --git a/kernel/sysctl.c b/kernel/sysctl.c index e961286d0e14..7adfe5dbce9d 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -201,6 +201,40 @@ static int max_extfrag_threshold = 1000; #endif /* CONFIG_SYSCTL */ +#ifdef CONFIG_BPF_SYSCALL +static int bpf_stats_handler(struct ctl_table *table, int write, + void __user *buffer, size_t *lenp, + loff_t *ppos) +{ + struct static_key *key = (struct static_key *)table->data; + static int saved_val; + int val, ret; + struct ctl_table tmp = { + .data = &val, + .maxlen = sizeof(val), + .mode = table->mode, + .extra1 = SYSCTL_ZERO, + .extra2 = SYSCTL_ONE, + }; + + if (write && !capable(CAP_SYS_ADMIN)) + return -EPERM; + + mutex_lock(&bpf_stats_enabled_mutex); + val = saved_val; + ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos); + if (write && !ret && val != saved_val) { + if (val) + static_key_slow_inc(key); + else + static_key_slow_dec(key); + saved_val = val; + } + mutex_unlock(&bpf_stats_enabled_mutex); + return ret; +} +#endif + /* * /proc/sys support */ @@ -2549,7 +2583,7 @@ static struct ctl_table kern_table[] = { .data = &bpf_stats_enabled_key.key, .maxlen = sizeof(bpf_stats_enabled_key), .mode = 0644, - .proc_handler = proc_do_static_key, + .proc_handler = bpf_stats_handler, }, #endif #if defined(CONFIG_TREE_RCU) |