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

Pull x86 PTI fixes from Ingo Molnar:
 "Two fixes: a relatively simple objtool fix that makes Clang built
  kernels work with ORC debug info, plus an alternatives macro fix"

* 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/alternatives: Fixup alternative_call_2
  objtool: Add Clang support
Linus Torvalds 7 years ago
parent
commit
93e04d4ad7
2 changed files with 12 additions and 3 deletions
  1. 1 3
      arch/x86/include/asm/alternative.h
  2. 11 0
      tools/objtool/check.c

+ 1 - 3
arch/x86/include/asm/alternative.h

@@ -218,13 +218,11 @@ static inline int alternatives_text_reserved(void *start, void *end)
  */
  */
 #define alternative_call_2(oldfunc, newfunc1, feature1, newfunc2, feature2,   \
 #define alternative_call_2(oldfunc, newfunc1, feature1, newfunc2, feature2,   \
 			   output, input...)				      \
 			   output, input...)				      \
-{									      \
 	asm volatile (ALTERNATIVE_2("call %P[old]", "call %P[new1]", feature1,\
 	asm volatile (ALTERNATIVE_2("call %P[old]", "call %P[new1]", feature1,\
 		"call %P[new2]", feature2)				      \
 		"call %P[new2]", feature2)				      \
 		: output, ASM_CALL_CONSTRAINT				      \
 		: output, ASM_CALL_CONSTRAINT				      \
 		: [old] "i" (oldfunc), [new1] "i" (newfunc1),		      \
 		: [old] "i" (oldfunc), [new1] "i" (newfunc1),		      \
-		  [new2] "i" (newfunc2), ## input);			      \
-}
+		  [new2] "i" (newfunc2), ## input)
 
 
 /*
 /*
  * use this macro(s) if you need more than one output parameter
  * use this macro(s) if you need more than one output parameter

+ 11 - 0
tools/objtool/check.c

@@ -1386,6 +1386,17 @@ static int update_insn_state(struct instruction *insn, struct insn_state *state)
 				state->vals[op->dest.reg].offset = -state->stack_size;
 				state->vals[op->dest.reg].offset = -state->stack_size;
 			}
 			}
 
 
+			else if (op->src.reg == CFI_BP && op->dest.reg == CFI_SP &&
+				 cfa->base == CFI_BP) {
+
+				/*
+				 * mov %rbp, %rsp
+				 *
+				 * Restore the original stack pointer (Clang).
+				 */
+				state->stack_size = -state->regs[CFI_BP].offset;
+			}
+
 			else if (op->dest.reg == cfa->base) {
 			else if (op->dest.reg == cfa->base) {
 
 
 				/* mov %reg, %rsp */
 				/* mov %reg, %rsp */