extern struct static_call_site __start_static_call_sites[],
__stop_static_call_sites[];
+extern struct static_call_tramp_key __start_static_call_tramp_key[],
+ __stop_static_call_tramp_key[];
static bool static_call_initialized;
return (void *)((long)site->addr + (long)&site->addr);
}
+static inline unsigned long __static_call_key(const struct static_call_site *site)
+{
+ return (long)site->key + (long)&site->key;
+}
static inline struct static_call_key *static_call_key(const struct static_call_site *site)
{
- return (struct static_call_key *)
- (((long)site->key + (long)&site->key) & ~STATIC_CALL_SITE_FLAGS);
+ return (void *)(__static_call_key(site) & ~STATIC_CALL_SITE_FLAGS);
}
/* These assume the key is word-aligned. */
static inline bool static_call_is_init(struct static_call_site *site)
{
- return ((long)site->key + (long)&site->key) & STATIC_CALL_SITE_INIT;
+ return __static_call_key(site) & STATIC_CALL_SITE_INIT;
}
static inline bool static_call_is_tail(struct static_call_site *site)
{
- return ((long)site->key + (long)&site->key) & STATIC_CALL_SITE_TAIL;
+ return __static_call_key(site) & STATIC_CALL_SITE_TAIL;
}
static inline void static_call_set_init(struct static_call_site *site)
{
- site->key = ((long)static_call_key(site) | STATIC_CALL_SITE_INIT) -
+ site->key = (__static_call_key(site) | STATIC_CALL_SITE_INIT) -
(long)&site->key;
}
};
for (site_mod = &first; site_mod; site_mod = site_mod->next) {
+ bool init = system_state < SYSTEM_RUNNING;
struct module *mod = site_mod->mod;
if (!site_mod->sites) {
stop = __stop_static_call_sites;
-#ifdef CONFIG_MODULES
if (mod) {
+#ifdef CONFIG_MODULES
stop = mod->static_call_sites +
mod->num_static_call_sites;
- }
+ init = mod->state == MODULE_STATE_COMING;
#endif
+ }
for (site = site_mod->sites;
site < stop && static_call_key(site) == key; site++) {
void *site_addr = static_call_addr(site);
- if (static_call_is_init(site)) {
- /*
- * Don't write to call sites which were in
- * initmem and have since been freed.
- */
- if (!mod && system_state >= SYSTEM_RUNNING)
- continue;
- if (mod && !within_module_init((unsigned long)site_addr, mod))
- continue;
- }
+ if (!init && static_call_is_init(site))
+ continue;
if (!kernel_text_address((unsigned long)site_addr)) {
- WARN_ONCE(1, "can't patch static call site at %pS",
+ /*
+ * This skips patching built-in __exit, which
+ * is part of init_section_contains() but is
+ * not part of kernel_text_address().
+ *
+ * Skipping built-in __exit is fine since it
+ * will never be executed.
+ */
+ WARN_ONCE(!static_call_is_init(site),
+ "can't patch static call site at %pS",
site_addr);
continue;
}
arch_static_call_transform(site_addr, NULL, func,
- static_call_is_tail(site));
+ static_call_is_tail(site));
}
}
static int __static_call_text_reserved(struct static_call_site *iter_start,
struct static_call_site *iter_stop,
- void *start, void *end)
+ void *start, void *end, bool init)
{
struct static_call_site *iter = iter_start;
while (iter < iter_stop) {
- if (addr_conflict(iter, start, end))
- return 1;
+ if (init || !static_call_is_init(iter)) {
+ if (addr_conflict(iter, start, end))
+ return 1;
+ }
iter++;
}
ret = __static_call_text_reserved(mod->static_call_sites,
mod->static_call_sites + mod->num_static_call_sites,
- start, end);
+ start, end, mod->state == MODULE_STATE_COMING);
module_put(mod);
return ret;
}
+static unsigned long tramp_key_lookup(unsigned long addr)
+{
+ struct static_call_tramp_key *start = __start_static_call_tramp_key;
+ struct static_call_tramp_key *stop = __stop_static_call_tramp_key;
+ struct static_call_tramp_key *tramp_key;
+
+ for (tramp_key = start; tramp_key != stop; tramp_key++) {
+ unsigned long tramp;
+
+ tramp = (long)tramp_key->tramp + (long)&tramp_key->tramp;
+ if (tramp == addr)
+ return (long)tramp_key->key + (long)&tramp_key->key;
+ }
+
+ return 0;
+}
+
static int static_call_add_module(struct module *mod)
{
- return __static_call_init(mod, mod->static_call_sites,
- mod->static_call_sites + mod->num_static_call_sites);
+ struct static_call_site *start = mod->static_call_sites;
+ struct static_call_site *stop = start + mod->num_static_call_sites;
+ struct static_call_site *site;
+
+ for (site = start; site != stop; site++) {
+ unsigned long s_key = __static_call_key(site);
+ unsigned long addr = s_key & ~STATIC_CALL_SITE_FLAGS;
+ unsigned long key;
+
+ /*
+ * Is the key is exported, 'addr' points to the key, which
+ * means modules are allowed to call static_call_update() on
+ * it.
+ *
+ * Otherwise, the key isn't exported, and 'addr' points to the
+ * trampoline so we need to lookup the key.
+ *
+ * We go through this dance to prevent crazy modules from
+ * abusing sensitive static calls.
+ */
+ if (!kernel_text_address(addr))
+ continue;
+
+ key = tramp_key_lookup(addr);
+ if (!key) {
+ pr_warn("Failed to fixup __raw_static_call() usage at: %ps\n",
+ static_call_addr(site));
+ return -EINVAL;
+ }
+
+ key |= s_key & STATIC_CALL_SITE_FLAGS;
+ site->key = key - (long)&site->key;
+ }
+
+ return __static_call_init(mod, start, stop);
}
static void static_call_del_module(struct module *mod)
int static_call_text_reserved(void *start, void *end)
{
+ bool init = system_state < SYSTEM_RUNNING;
int ret = __static_call_text_reserved(__start_static_call_sites,
- __stop_static_call_sites, start, end);
+ __stop_static_call_sites, start, end, init);
if (ret)
return ret;
projects / platform / kernel / linux-rpi.git / blobdiff