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authorLinus Torvalds <torvalds@linux-foundation.org>2018-08-13 17:01:03 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2018-08-13 17:01:03 -0700
commit4d5ac4b8ca1ecbdb600097a26071abc5b47500bf (patch)
tree4ccef33588c8a944140b291646fd741ef493cb62 /arch
parent203b4fc903b644223a27ad3f25f3a0f3a3911d1d (diff)
parent5800dc5c19f34e6e03b5adab1282535cb102fafd (diff)
download96b-common-4d5ac4b8ca1ecbdb600097a26071abc5b47500bf.tar.gz
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
Diffstat (limited to 'arch')
-rw-r--r--arch/x86/include/asm/irqflags.h2
-rw-r--r--arch/x86/kernel/paravirt.c14
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;