diff options
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/jump_label.c | 53 | ||||
| -rw-r--r-- | kernel/ptrace.c | 4 | ||||
| -rw-r--r-- | kernel/seccomp.c | 6 |
3 files changed, 58 insertions, 5 deletions
diff --git a/kernel/jump_label.c b/kernel/jump_label.c index 0dbea887d625..f19aa02a8f48 100644 --- a/kernel/jump_label.c +++ b/kernel/jump_label.c @@ -14,6 +14,7 @@ #include <linux/err.h> #include <linux/static_key.h> #include <linux/jump_label_ratelimit.h> +#include <linux/bug.h> #ifdef HAVE_JUMP_LABEL @@ -56,6 +57,49 @@ jump_label_sort_entries(struct jump_entry *start, struct jump_entry *stop) static void jump_label_update(struct static_key *key); +/* + * There are similar definitions for the !HAVE_JUMP_LABEL case in jump_label.h. + * The use of 'atomic_read()' requires atomic.h and its problematic for some + * kernel headers such as kernel.h and others. Since static_key_count() is not + * used in the branch statements as it is for the !HAVE_JUMP_LABEL case its ok + * to have it be a function here. Similarly, for 'static_key_enable()' and + * 'static_key_disable()', which require bug.h. This should allow jump_label.h + * to be included from most/all places for HAVE_JUMP_LABEL. + */ +int static_key_count(struct static_key *key) +{ + /* + * -1 means the first static_key_slow_inc() is in progress. + * static_key_enabled() must return true, so return 1 here. + */ + int n = atomic_read(&key->enabled); + + return n >= 0 ? n : 1; +} +EXPORT_SYMBOL_GPL(static_key_count); + +void static_key_enable(struct static_key *key) +{ + int count = static_key_count(key); + + WARN_ON_ONCE(count < 0 || count > 1); + + if (!count) + static_key_slow_inc(key); +} +EXPORT_SYMBOL_GPL(static_key_enable); + +void static_key_disable(struct static_key *key) +{ + int count = static_key_count(key); + + WARN_ON_ONCE(count < 0 || count > 1); + + if (count) + static_key_slow_dec(key); +} +EXPORT_SYMBOL_GPL(static_key_disable); + void static_key_slow_inc(struct static_key *key) { int v, v1; @@ -235,6 +279,15 @@ void __init jump_label_init(void) struct static_key *key = NULL; struct jump_entry *iter; + /* + * Since we are initializing the static_key.enabled field with + * with the 'raw' int values (to avoid pulling in atomic.h) in + * jump_label.h, let's make sure that is safe. There are only two + * cases to check since we initialize to 0 or 1. + */ + BUILD_BUG_ON((int)ATOMIC_INIT(0) != 0); + BUILD_BUG_ON((int)ATOMIC_INIT(1) != 1); + jump_label_lock(); jump_label_sort_entries(iter_start, iter_stop); diff --git a/kernel/ptrace.c b/kernel/ptrace.c index d49bfa1e53e6..1d3b7665d0be 100644 --- a/kernel/ptrace.c +++ b/kernel/ptrace.c @@ -585,8 +585,8 @@ static int ptrace_setoptions(struct task_struct *child, unsigned long data) return -EINVAL; if (unlikely(data & PTRACE_O_SUSPEND_SECCOMP)) { - if (!config_enabled(CONFIG_CHECKPOINT_RESTORE) || - !config_enabled(CONFIG_SECCOMP)) + if (!IS_ENABLED(CONFIG_CHECKPOINT_RESTORE) || + !IS_ENABLED(CONFIG_SECCOMP)) return -EINVAL; if (!capable(CAP_SYS_ADMIN)) diff --git a/kernel/seccomp.c b/kernel/seccomp.c index 54d15eb2b701..ef6c6c3f9d8a 100644 --- a/kernel/seccomp.c +++ b/kernel/seccomp.c @@ -347,7 +347,7 @@ static struct seccomp_filter *seccomp_prepare_filter(struct sock_fprog *fprog) { struct seccomp_filter *sfilter; int ret; - const bool save_orig = config_enabled(CONFIG_CHECKPOINT_RESTORE); + const bool save_orig = IS_ENABLED(CONFIG_CHECKPOINT_RESTORE); if (fprog->len == 0 || fprog->len > BPF_MAXINSNS) return ERR_PTR(-EINVAL); @@ -542,7 +542,7 @@ void secure_computing_strict(int this_syscall) { int mode = current->seccomp.mode; - if (config_enabled(CONFIG_CHECKPOINT_RESTORE) && + if (IS_ENABLED(CONFIG_CHECKPOINT_RESTORE) && unlikely(current->ptrace & PT_SUSPEND_SECCOMP)) return; @@ -655,7 +655,7 @@ int __secure_computing(const struct seccomp_data *sd) int mode = current->seccomp.mode; int this_syscall; - if (config_enabled(CONFIG_CHECKPOINT_RESTORE) && + if (IS_ENABLED(CONFIG_CHECKPOINT_RESTORE) && unlikely(current->ptrace & PT_SUSPEND_SECCOMP)) return 0; |