Revert "x86/speculation: Change FILL_RETURN_BUFFER to work with objtool"

This reverts commit c95afe5bcad40e1f0292bfc0a625c4aa080cc971, which
was commit 089dd8e53126ebaf506e2dc0bf89d652c36bfc12 upstream.

The necessary changes to objtool have not been backported to 4.14.
Backporting this commit alone only added build warnings.

Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/arch/x86/include/asm/nospec-branch.h b/arch/x86/include/asm/nospec-branch.h
index d23b92c0ddeab59ae2c1c7e0b4860d9fae4f4b66..0b65fea3c0e226cc425016451d7578ebf0f7a146 100644 (file)
--- a/arch/x86/include/asm/nospec-branch.h
+++ b/arch/x86/include/asm/nospec-branch.h
@@ -4,13 +4,11 @@
 #define _ASM_X86_NOSPEC_BRANCH_H_
 
 #include <linux/static_key.h>
-#include <linux/frame.h>
 
 #include <asm/alternative.h>
 #include <asm/alternative-asm.h>
 #include <asm/cpufeatures.h>
 #include <asm/msr-index.h>
-#include <asm/unwind_hints.h>
 #include <asm/percpu.h>
 
 /*
@@ -54,9 +52,9 @@
        lfence;                                 \
        jmp     775b;                           \
 774:                                           \
-       add     $(BITS_PER_LONG/8) * 2, sp;     \
        dec     reg;                            \
        jnz     771b;                           \
+       add     $(BITS_PER_LONG/8) * nr, sp;    \
        /* barrier for jnz misprediction */     \
        lfence;
 #else
@@ -167,8 +165,10 @@
   * monstrosity above, manually.
   */
 .macro FILL_RETURN_BUFFER reg:req nr:req ftr:req
-       ALTERNATIVE "jmp .Lskip_rsb_\@", "", \ftr
-       __FILL_RETURN_BUFFER(\reg,\nr,%_ASM_SP)
+       ANNOTATE_NOSPEC_ALTERNATIVE
+       ALTERNATIVE "jmp .Lskip_rsb_\@",                                \
+               __stringify(__FILL_RETURN_BUFFER(\reg,\nr,%_ASM_SP))    \
+               \ftr
 .Lskip_rsb_\@:
 .endm