Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull misc x86 fixes from Thomas Gleixner:
 "Two fixes for x86:

   - Provide a declaration for native_save_fl() which unbreaks the
     wreckage caused by making it 'extern inline'.

   - Fix the failing paravirt patching which is supposed to replace
     indirect with direct calls. The wreckage is caused by an incorrect
     clobber test"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/paravirt: Fix spectre-v2 mitigations for paravirt guests
  x86/irqflags: Provide a declaration for native_save_fl

2 files changed, 12 insertions, 4 deletions

diff --git a/arch/x86/include/asm/irqflags.h b/arch/x86/include/asm/irqflags.h
index c4fc17220df9..c14f2a74b2be 100644
--- a/arch/x86/include/asm/irqflags.h
+++ b/arch/x86/include/asm/irqflags.h
@@ -13,6 +13,8 @@
  * Interrupt control:
  */
 
+/* Declaration required for gcc < 4.9 to prevent -Werror=missing-prototypes */
+extern inline unsigned long native_save_fl(void);
 extern inline unsigned long native_save_fl(void)
 {
         unsigned long flags;
diff --git a/arch/x86/kernel/paravirt.c b/arch/x86/kernel/paravirt.c
index 99dc79e76bdc..930c88341e4e 100644
--- a/arch/x86/kernel/paravirt.c
+++ b/arch/x86/kernel/paravirt.c
@@ -88,10 +88,12 @@ unsigned paravirt_patch_call(void *insnbuf,
         struct branch *b = insnbuf;
         unsigned long delta = (unsigned long)target - (addr+5);
 
-        if (tgt_clobbers & ~site_clobbers)
-                return len;     /* target would clobber too much for this site */
-        if (len < 5)
+        if (len < 5) {
+#ifdef CONFIG_RETPOLINE
+                WARN_ONCE("Failing to patch indirect CALL in %ps\n", (void *)addr);
+#endif
                 return len;     /* call too long for patch site */
+        }
 
         b->opcode = 0xe8; /* call */
         b->delta = delta;
@@ -106,8 +108,12 @@ unsigned paravirt_patch_jmp(void *insnbuf, const void *target,
         struct branch *b = insnbuf;
         unsigned long delta = (unsigned long)target - (addr+5);
 
-        if (len < 5)
+        if (len < 5) {
+#ifdef CONFIG_RETPOLINE
+                WARN_ONCE("Failing to patch indirect JMP in %ps\n", (void *)addr);
+#endif
                 return len;     /* call too long for patch site */
+        }
 
         b->opcode = 0xe9;       /* jmp */
         b->delta = delta;