diff options
Diffstat (limited to 'kernel/bpf')
-rw-r--r-- | kernel/bpf/syscall.c | 87 |
1 files changed, 87 insertions, 0 deletions
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index cdaa1152436a..e9621cfa09f2 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -4908,3 +4908,90 @@ const struct bpf_verifier_ops bpf_syscall_verifier_ops = { const struct bpf_prog_ops bpf_syscall_prog_ops = { .test_run = bpf_prog_test_run_syscall, }; + +#ifdef CONFIG_SYSCTL +static int bpf_stats_handler(struct ctl_table *table, int write, + void *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; +} + +void __weak unpriv_ebpf_notify(int new_state) +{ +} + +static int bpf_unpriv_handler(struct ctl_table *table, int write, + void *buffer, size_t *lenp, loff_t *ppos) +{ + int ret, unpriv_enable = *(int *)table->data; + bool locked_state = unpriv_enable == 1; + struct ctl_table tmp = *table; + + if (write && !capable(CAP_SYS_ADMIN)) + return -EPERM; + + tmp.data = &unpriv_enable; + ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos); + if (write && !ret) { + if (locked_state && unpriv_enable != 1) + return -EPERM; + *(int *)table->data = unpriv_enable; + } + + unpriv_ebpf_notify(unpriv_enable); + + return ret; +} + +static struct ctl_table bpf_syscall_table[] = { + { + .procname = "unprivileged_bpf_disabled", + .data = &sysctl_unprivileged_bpf_disabled, + .maxlen = sizeof(sysctl_unprivileged_bpf_disabled), + .mode = 0644, + .proc_handler = bpf_unpriv_handler, + .extra1 = SYSCTL_ZERO, + .extra2 = SYSCTL_TWO, + }, + { + .procname = "bpf_stats_enabled", + .data = &bpf_stats_enabled_key.key, + .maxlen = sizeof(bpf_stats_enabled_key), + .mode = 0644, + .proc_handler = bpf_stats_handler, + }, + { } +}; + +static int __init bpf_syscall_sysctl_init(void) +{ + register_sysctl_init("kernel", bpf_syscall_table); + return 0; +} +late_initcall(bpf_syscall_sysctl_init); +#endif /* CONFIG_SYSCTL */ |