diff options
| -rw-r--r-- | arch/x86/kernel/alternative.c | 26 | ||||
| -rw-r--r-- | kernel/extable.c | 2 |
2 files changed, 15 insertions, 13 deletions
diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c index 3344d3382e91..dbaf14d69ebd 100644 --- a/arch/x86/kernel/alternative.c +++ b/arch/x86/kernel/alternative.c @@ -442,7 +442,6 @@ static void alternatives_smp_lock(const s32 *start, const s32 *end, { const s32 *poff; - mutex_lock(&text_mutex); for (poff = start; poff < end; poff++) { u8 *ptr = (u8 *)poff + *poff; @@ -452,7 +451,6 @@ static void alternatives_smp_lock(const s32 *start, const s32 *end, if (*ptr == 0x3e) text_poke(ptr, ((unsigned char []){0xf0}), 1); } - mutex_unlock(&text_mutex); } static void alternatives_smp_unlock(const s32 *start, const s32 *end, @@ -460,7 +458,6 @@ static void alternatives_smp_unlock(const s32 *start, const s32 *end, { const s32 *poff; - mutex_lock(&text_mutex); for (poff = start; poff < end; poff++) { u8 *ptr = (u8 *)poff + *poff; @@ -470,7 +467,6 @@ static void alternatives_smp_unlock(const s32 *start, const s32 *end, if (*ptr == 0xf0) text_poke(ptr, ((unsigned char []){0x3E}), 1); } - mutex_unlock(&text_mutex); } struct smp_alt_module { @@ -489,8 +485,7 @@ struct smp_alt_module { struct list_head next; }; static LIST_HEAD(smp_alt_modules); -static DEFINE_MUTEX(smp_alt); -static bool uniproc_patched = false; /* protected by smp_alt */ +static bool uniproc_patched = false; /* protected by text_mutex */ void __init_or_module alternatives_smp_module_add(struct module *mod, char *name, @@ -499,7 +494,7 @@ void __init_or_module alternatives_smp_module_add(struct module *mod, { struct smp_alt_module *smp; - mutex_lock(&smp_alt); + mutex_lock(&text_mutex); if (!uniproc_patched) goto unlock; @@ -526,14 +521,14 @@ void __init_or_module alternatives_smp_module_add(struct module *mod, smp_unlock: alternatives_smp_unlock(locks, locks_end, text, text_end); unlock: - mutex_unlock(&smp_alt); + mutex_unlock(&text_mutex); } void __init_or_module alternatives_smp_module_del(struct module *mod) { struct smp_alt_module *item; - mutex_lock(&smp_alt); + mutex_lock(&text_mutex); list_for_each_entry(item, &smp_alt_modules, next) { if (mod != item->mod) continue; @@ -541,7 +536,7 @@ void __init_or_module alternatives_smp_module_del(struct module *mod) kfree(item); break; } - mutex_unlock(&smp_alt); + mutex_unlock(&text_mutex); } void alternatives_enable_smp(void) @@ -551,7 +546,7 @@ void alternatives_enable_smp(void) /* Why bother if there are no other CPUs? */ BUG_ON(num_possible_cpus() == 1); - mutex_lock(&smp_alt); + mutex_lock(&text_mutex); if (uniproc_patched) { pr_info("switching to SMP code\n"); @@ -563,10 +558,13 @@ void alternatives_enable_smp(void) mod->text, mod->text_end); uniproc_patched = false; } - mutex_unlock(&smp_alt); + mutex_unlock(&text_mutex); } -/* Return 1 if the address range is reserved for smp-alternatives */ +/* + * Return 1 if the address range is reserved for SMP-alternatives. + * Must hold text_mutex. + */ int alternatives_text_reserved(void *start, void *end) { struct smp_alt_module *mod; @@ -574,6 +572,8 @@ int alternatives_text_reserved(void *start, void *end) u8 *text_start = start; u8 *text_end = end; + lockdep_assert_held(&text_mutex); + list_for_each_entry(mod, &smp_alt_modules, next) { if (mod->text > text_end || mod->text_end < text_start) continue; diff --git a/kernel/extable.c b/kernel/extable.c index 9aa1cc41ecf7..a17fdb63dc3e 100644 --- a/kernel/extable.c +++ b/kernel/extable.c @@ -31,6 +31,8 @@ * mutex protecting text section modification (dynamic code patching). * some users need to sleep (allocating memory...) while they hold this lock. * + * Note: Also protects SMP-alternatives modification on x86. + * * NOT exported to modules - patching kernel text is a really delicate matter. */ DEFINE_MUTEX(text_mutex); |