[tip: objtool/urgent] objtool/x86: Ignore __x86_indirect_alt_* symbols

From: tip-bot2 for Peter Zijlstra
Date: Mon Jun 21 2021 - 13:55:41 EST


The following commit has been merged into the objtool/urgent branch of tip:

Commit-ID: 31197d3a0f1caeb60fb01f6755e28347e4f44037
Gitweb: https://git.kernel.org/tip/31197d3a0f1caeb60fb01f6755e28347e4f44037
Author: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
AuthorDate: Mon, 21 Jun 2021 16:13:55 +02:00
Committer: Ingo Molnar <mingo@xxxxxxxxxx>
CommitterDate: Mon, 21 Jun 2021 17:26:57 +02:00

objtool/x86: Ignore __x86_indirect_alt_* symbols

Because the __x86_indirect_alt* symbols are just that, objtool will
try and validate them as regular symbols, instead of the alternative
replacements that they are.

This goes sideways for FRAME_POINTER=y builds; which generate a fair
amount of warnings.

Fixes: 9bc0bb50727c ("objtool/x86: Rewrite retpoline thunk calls")
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
Link: https://lore.kernel.org/r/YNCgxwLBiK9wclYJ@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
---
arch/x86/lib/retpoline.S | 4 ++++
1 file changed, 4 insertions(+)

diff --git a/arch/x86/lib/retpoline.S b/arch/x86/lib/retpoline.S
index 4d32cb0..ec9922c 100644
--- a/arch/x86/lib/retpoline.S
+++ b/arch/x86/lib/retpoline.S
@@ -58,12 +58,16 @@ SYM_FUNC_START_NOALIGN(__x86_indirect_alt_call_\reg)
2: .skip 5-(2b-1b), 0x90
SYM_FUNC_END(__x86_indirect_alt_call_\reg)

+STACK_FRAME_NON_STANDARD(__x86_indirect_alt_call_\reg)
+
SYM_FUNC_START_NOALIGN(__x86_indirect_alt_jmp_\reg)
ANNOTATE_RETPOLINE_SAFE
1: jmp *%\reg
2: .skip 5-(2b-1b), 0x90
SYM_FUNC_END(__x86_indirect_alt_jmp_\reg)

+STACK_FRAME_NON_STANDARD(__x86_indirect_alt_jmp_\reg)
+
.endm

/*