Merge branch into tip/master: 'x86/alternatives'

 # New commits in x86/alternatives:
    4a73b93ce489 ("x86/alternative: Drop smp_locks glue")

Signed-off-by: Ingo Molnar <mingo@kernel.org>

6 files changed, 1 insertions, 221 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
diff --git a/arch/x86/kernel/kprobes/core.c b/arch/x86/kernel/kprobes/core.c
index c1fac3a9fecc..4e5f8c1736ec 100644
--- a/arch/x86/kernel/kprobes/core.c
+++ b/arch/x86/kernel/kprobes/core.c
@@ -762,9 +762,6 @@ int arch_prepare_kprobe(struct kprobe *p)
 {
 	int ret;
 
-	if (alternatives_text_reserved(p->addr, p->addr))
-		return -EINVAL;
-
 	if (!can_probe((unsigned long)p->addr))
 		return -EILSEQ;
 
diff --git a/arch/x86/kernel/kprobes/opt.c b/arch/x86/kernel/kprobes/opt.c
index c994b0745983..3f8fea52619f 100644
--- a/arch/x86/kernel/kprobes/opt.c
+++ b/arch/x86/kernel/kprobes/opt.c
@@ -213,7 +213,6 @@ static int copy_optimized_instructions(u8 *dest, u8 *src, u8 *real)
 	}
 	/* Check whether the address range is reserved */
 	if (ftrace_text_reserved(src, src + len - 1) ||
-	    alternatives_text_reserved(src, src + len - 1) ||
 	    jump_label_text_reserved(src, src + len - 1) ||
 	    static_call_text_reserved(src, src + len - 1))
 		return -EBUSY;
diff --git a/arch/x86/kernel/module.c b/arch/x86/kernel/module.c
index b5b4de4f08e6..33080ad889b7 100644
--- a/arch/x86/kernel/module.c
+++ b/arch/x86/kernel/module.c
@@ -227,7 +227,7 @@ int module_finalize(const Elf_Ehdr *hdr,
 		    const Elf_Shdr *sechdrs,
 		    struct module *me)
 {
-	const Elf_Shdr *s, *alt = NULL, *locks = NULL,
+	const Elf_Shdr *s, *alt = NULL,
 		*orc = NULL, *orc_ip = NULL,
 		*retpolines = NULL, *returns = NULL, *ibt_endbr = NULL,
 		*calls = NULL, *cfi = NULL;
@@ -236,8 +236,6 @@ int module_finalize(const Elf_Ehdr *hdr,
 	for (s = sechdrs; s < sechdrs + hdr->e_shnum; s++) {
 		if (!strcmp(".altinstructions", secstrings + s->sh_name))
 			alt = s;
-		if (!strcmp(".smp_locks", secstrings + s->sh_name))
-			locks = s;
 		if (!strcmp(".orc_unwind", secstrings + s->sh_name))
 			orc = s;
 		if (!strcmp(".orc_unwind_ip", secstrings + s->sh_name))
@@ -300,14 +298,6 @@ int module_finalize(const Elf_Ehdr *hdr,
 		void *iseg = (void *)ibt_endbr->sh_addr;
 		apply_seal_endbr(iseg, iseg + ibt_endbr->sh_size);
 	}
-	if (locks) {
-		void *lseg = (void *)locks->sh_addr;
-		void *text = me->mem[MOD_TEXT].base;
-		void *text_end = text + me->mem[MOD_TEXT].size;
-		alternatives_smp_module_add(me, me->name,
-					    lseg, lseg + locks->sh_size,
-					    text, text_end);
-	}
 
 	if (orc && orc_ip)
 		unwind_module_init(me, (void *)orc_ip->sh_addr, orc_ip->sh_size,
@@ -318,6 +308,5 @@ int module_finalize(const Elf_Ehdr *hdr,
 
 void module_arch_cleanup(struct module *mod)
 {
-	alternatives_smp_module_del(mod);
 	its_free_mod(mod);
 }
diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
index cb999feb66b0..ba01a9e919b7 100644
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -991,9 +991,6 @@ int common_cpu_up(unsigned int cpu, struct task_struct *idle)
 {
 	int ret;
 
-	/* Just in case we booted with a single CPU. */
-	alternatives_enable_smp();
-
 	per_cpu(current_task, cpu) = idle;
 	cpu_init_stack_canary(cpu, idle);
 
diff --git a/arch/x86/kernel/vmlinux.lds.S b/arch/x86/kernel/vmlinux.lds.S
index 81e113eb7c7c..e371a439deb6 100644
--- a/arch/x86/kernel/vmlinux.lds.S
+++ b/arch/x86/kernel/vmlinux.lds.S
@@ -346,18 +346,6 @@ SECTIONS
 		__init_end = .;
 	}
 
-	/*
-	 * smp_locks might be freed after init
-	 * start/end must be page aligned
-	 */
-	. = ALIGN(PAGE_SIZE);
-	.smp_locks : AT(ADDR(.smp_locks) - LOAD_OFFSET) {
-		__smp_locks = .;
-		*(.smp_locks)
-		. = ALIGN(PAGE_SIZE);
-		__smp_locks_end = .;
-	}
-
 #ifdef CONFIG_X86_64
 	.data_nosave : AT(ADDR(.data_nosave) - LOAD_OFFSET) {
 		NOSAVE_DATA