diff options
Diffstat (limited to 'arch/x86/kernel/alternative.c')
| -rw-r--r-- | arch/x86/kernel/alternative.c | 190 |
1 files changed, 0 insertions, 190 deletions
diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c index 62936a3bde19..bf717b4159ba 100644 --- a/arch/x86/kernel/alternative.c +++ b/arch/x86/kernel/alternative.c @@ -41,15 +41,6 @@ static int __init debug_alt(char *str) } __setup("debug-alternative", debug_alt); -static int noreplace_smp; - -static int __init setup_noreplace_smp(char *str) -{ - noreplace_smp = 1; - return 1; -} -__setup("noreplace-smp", setup_noreplace_smp); - #define DPRINTK(type, fmt, args...) \ do { \ if (debug_alternative & DA_##type) \ @@ -2109,159 +2100,6 @@ void apply_fineibt(s32 *start_retpoline, s32 *end_retpoline, /* .builtin = */ false); } -#ifdef CONFIG_SMP -static void alternatives_smp_lock(const s32 *start, const s32 *end, - u8 *text, u8 *text_end) -{ - const s32 *poff; - - for (poff = start; poff < end; poff++) { - u8 *ptr = (u8 *)poff + *poff; - - if (!*poff || ptr < text || ptr >= text_end) - continue; - /* turn DS segment override prefix into lock prefix */ - if (*ptr == 0x3e) - text_poke(ptr, ((unsigned char []){0xf0}), 1); - } -} - -static void alternatives_smp_unlock(const s32 *start, const s32 *end, - u8 *text, u8 *text_end) -{ - const s32 *poff; - - for (poff = start; poff < end; poff++) { - u8 *ptr = (u8 *)poff + *poff; - - if (!*poff || ptr < text || ptr >= text_end) - continue; - /* turn lock prefix into DS segment override prefix */ - if (*ptr == 0xf0) - text_poke(ptr, ((unsigned char []){0x3E}), 1); - } -} - -struct smp_alt_module { - /* what is this ??? */ - struct module *mod; - char *name; - - /* ptrs to lock prefixes */ - const s32 *locks; - const s32 *locks_end; - - /* .text segment, needed to avoid patching init code ;) */ - u8 *text; - u8 *text_end; - - struct list_head next; -}; -static LIST_HEAD(smp_alt_modules); -static bool uniproc_patched = false; /* protected by text_mutex */ - -void __init_or_module alternatives_smp_module_add(struct module *mod, - char *name, - void *locks, void *locks_end, - void *text, void *text_end) -{ - struct smp_alt_module *smp; - - mutex_lock(&text_mutex); - if (!uniproc_patched) - goto unlock; - - if (num_possible_cpus() == 1) - /* Don't bother remembering, we'll never have to undo it. */ - goto smp_unlock; - - smp = kzalloc_obj(*smp); - if (NULL == smp) - /* we'll run the (safe but slow) SMP code then ... */ - goto unlock; - - smp->mod = mod; - smp->name = name; - smp->locks = locks; - smp->locks_end = locks_end; - smp->text = text; - smp->text_end = text_end; - DPRINTK(SMP, "locks %p -> %p, text %p -> %p, name %s\n", - smp->locks, smp->locks_end, - smp->text, smp->text_end, smp->name); - - list_add_tail(&smp->next, &smp_alt_modules); -smp_unlock: - alternatives_smp_unlock(locks, locks_end, text, text_end); -unlock: - mutex_unlock(&text_mutex); -} - -void __init_or_module alternatives_smp_module_del(struct module *mod) -{ - struct smp_alt_module *item; - - mutex_lock(&text_mutex); - list_for_each_entry(item, &smp_alt_modules, next) { - if (mod != item->mod) - continue; - list_del(&item->next); - kfree(item); - break; - } - mutex_unlock(&text_mutex); -} - -void alternatives_enable_smp(void) -{ - struct smp_alt_module *mod; - - /* Why bother if there are no other CPUs? */ - BUG_ON(num_possible_cpus() == 1); - - mutex_lock(&text_mutex); - - if (uniproc_patched) { - pr_info("switching to SMP code\n"); - BUG_ON(num_online_cpus() != 1); - clear_cpu_cap(&boot_cpu_data, X86_FEATURE_UP); - clear_cpu_cap(&cpu_data(0), X86_FEATURE_UP); - list_for_each_entry(mod, &smp_alt_modules, next) - alternatives_smp_lock(mod->locks, mod->locks_end, - mod->text, mod->text_end); - uniproc_patched = false; - } - mutex_unlock(&text_mutex); -} - -/* - * 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; - const s32 *poff; - 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; - for (poff = mod->locks; poff < mod->locks_end; poff++) { - const u8 *ptr = (const u8 *)poff + *poff; - - if (text_start <= ptr && text_end > ptr) - return 1; - } - } - - return 0; -} -#endif /* CONFIG_SMP */ - /* * Self-test for the INT3 based CALL emulation code. * @@ -2440,40 +2278,12 @@ void __init alternative_instructions(void) ibt_restore(ibt); -#ifdef CONFIG_SMP - /* Patch to UP if other cpus not imminent. */ - if (!noreplace_smp && (num_present_cpus() == 1 || setup_max_cpus <= 1)) { - uniproc_patched = true; - alternatives_smp_module_add(NULL, "core kernel", - __smp_locks, __smp_locks_end, - _text, _etext); - } -#endif - restart_nmi(); alternatives_patched = 1; alt_reloc_selftest(); } -#ifdef CONFIG_SMP -/* - * With CONFIG_DEFERRED_STRUCT_PAGE_INIT enabled we can free_init_pages() only - * after the deferred initialization of the memory map is complete. - */ -static int __init free_smp_locks(void) -{ - if (!uniproc_patched || num_possible_cpus() == 1) { - free_init_pages("SMP alternatives", - (unsigned long)__smp_locks, - (unsigned long)__smp_locks_end); - } - - return 0; -} -arch_initcall(free_smp_locks); -#endif - /** * text_poke_early - Update instructions on a live kernel at boot time * @addr: address to modify |