Merge tag 'x86_alternatives_for_v6.10_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 asm alternatives updates from Borislav Petkov:

 - Switch the in-place instruction patching which lead to at least one
   weird bug with 32-bit guests, seeing stale instruction bytes, to one
   working on a buffer, like the rest of the alternatives code does

 - Add a long overdue check to the X86_FEATURE flag modifying functions
   to warn when former get changed in a non-compatible way after
   alternatives have been patched because those changes will be already
   wrong

 - Other cleanups

* tag 'x86_alternatives_for_v6.10_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/alternatives: Remove alternative_input_2()
  x86/alternatives: Sort local vars in apply_alternatives()
  x86/alternatives: Optimize optimize_nops()
  x86/alternatives: Get rid of __optimize_nops()
  x86/alternatives: Use a temporary buffer when optimizing NOPs
  x86/alternatives: Catch late X86_FEATURE modifiers

3 files changed, 7 insertions, 17 deletions

diff --git a/arch/x86/include/asm/alternative.h b/arch/x86/include/asm/alternative.h
index 0cb2396de066..ba99ef75f56c 100644
--- a/arch/x86/include/asm/alternative.h
+++ b/arch/x86/include/asm/alternative.h
@@ -286,20 +286,6 @@ static inline int alternatives_text_reserved(void *start, void *end)
 	asm_inline volatile (ALTERNATIVE(oldinstr, newinstr, ft_flags)	\
 		: : "i" (0), ## input)
 
-/*
- * This is similar to alternative_input. But it has two features and
- * respective instructions.
- *
- * If CPU has feature2, newinstr2 is used.
- * Otherwise, if CPU has feature1, newinstr1 is used.
- * Otherwise, oldinstr is used.
- */
-#define alternative_input_2(oldinstr, newinstr1, ft_flags1, newinstr2,	\
-			   ft_flags2, input...)				\
-	asm_inline volatile(ALTERNATIVE_2(oldinstr, newinstr1, ft_flags1, \
-		newinstr2, ft_flags2)					\
-		: : "i" (0), ## input)
-
 /* Like alternative_input, but with a single output argument */
 #define alternative_io(oldinstr, newinstr, ft_flags, output, input...)	\
 	asm_inline volatile (ALTERNATIVE(oldinstr, newinstr, ft_flags)	\
diff --git a/arch/x86/include/asm/cpufeature.h b/arch/x86/include/asm/cpufeature.h
index b96f9cabea0c..0b9611da6c53 100644
--- a/arch/x86/include/asm/cpufeature.h
+++ b/arch/x86/include/asm/cpufeature.h
@@ -149,8 +149,12 @@ extern const char * const x86_bug_flags[NBUGINTS*32];
 extern void setup_clear_cpu_cap(unsigned int bit);
 extern void clear_cpu_cap(struct cpuinfo_x86 *c, unsigned int bit);
 
-#define setup_force_cpu_cap(bit) do { \
-	set_cpu_cap(&boot_cpu_data, bit);	\
+#define setup_force_cpu_cap(bit) do {			\
+							\
+	if (!boot_cpu_has(bit))				\
+		WARN_ON(alternatives_patched);		\
+							\
+	set_cpu_cap(&boot_cpu_data, bit);		\
 	set_bit(bit, (unsigned long *)cpu_caps_set);	\
 } while (0)
 
diff --git a/arch/x86/include/asm/text-patching.h b/arch/x86/include/asm/text-patching.h
index 345aafbc1964..6259f1937fe7 100644
--- a/arch/x86/include/asm/text-patching.h
+++ b/arch/x86/include/asm/text-patching.h
@@ -15,7 +15,7 @@
 
 extern void text_poke_early(void *addr, const void *opcode, size_t len);
 
-extern void apply_relocation(u8 *buf, size_t len, u8 *dest, u8 *src, size_t src_len);
+extern void apply_relocation(u8 *buf, const u8 * const instr, size_t instrlen, u8 *repl, size_t repl_len);
 
 /*
  * Clear and restore the kernel write-protection flag on the local CPU.