[GIT PULL] x86 PTI fixes

From: Ingo Molnar
Date: Sat Mar 31 2018 - 06:37:24 EST


Linus,

Please pull the latest x86-pti-for-linus git tree from:

git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git x86-pti-for-linus

# HEAD: bd6271039ee6f0c9b468148fc2d73e0584af6b4f x86/alternatives: Fixup alternative_call_2

Two fixes: a relatively simple objtool fix that makes Clang built kernels work
with ORC debug info, plus an alternatives macro fix.

out-of-topic modifications in x86-pti-for-linus:
--------------------------------------------------
tools/objtool/check.c # 3c1f05835cbf: objtool: Add Clang support

Thanks,

Ingo

------------------>
Alexey Dobriyan (1):
x86/alternatives: Fixup alternative_call_2

Josh Poimboeuf (1):
objtool: Add Clang support


arch/x86/include/asm/alternative.h | 4 +---
tools/objtool/check.c | 11 +++++++++++
2 files changed, 12 insertions(+), 3 deletions(-)

diff --git a/arch/x86/include/asm/alternative.h b/arch/x86/include/asm/alternative.h
index cf5961ca8677..4cd6a3b71824 100644
--- a/arch/x86/include/asm/alternative.h
+++ b/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, \
output, input...) \
-{ \
asm volatile (ALTERNATIVE_2("call %P[old]", "call %P[new1]", feature1,\
"call %P[new2]", feature2) \
: output, ASM_CALL_CONSTRAINT \
: [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
diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index 92b6a2c21631..5409f6f6c48d 100644
--- a/tools/objtool/check.c
+++ b/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;
}

+ 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) {

/* mov %reg, %rsp */