x86/retpoline: Add NOENDBR annotation to the SRSO dummy return thunk

commit b377c66ae3509ccea596512d6afb4777711c4870 upstream.

srso_alias_untrain_ret() is special code, even if it is a dummy
which is called in the !SRSO case, so annotate it like its real
counterpart, to address the following objtool splat:

  vmlinux.o: warning: objtool: .export_symbol+0x2b290: data relocation to !ENDBR: srso_alias_untrain_ret+0x0

Fixes: 4535e1a4174c ("x86/bugs: Fix the SRSO mitigation on Zen3/4")
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/r/20240405144637.17908-1-bp@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/arch/x86/lib/retpoline.S b/arch/x86/lib/retpoline.S
index 019096b66eff353892a75c50491d56fdae3afebb..ab9b047790dd0e762a2408da26d036cdc3bd50fc 100644 (file)
--- a/arch/x86/lib/retpoline.S
+++ b/arch/x86/lib/retpoline.S
@@ -258,6 +258,7 @@ SYM_CODE_START(__x86_return_thunk)
        UNWIND_HINT_FUNC
        ANNOTATE_NOENDBR
        ANNOTATE_UNRET_SAFE
+       ANNOTATE_NOENDBR
        ret
        int3
 SYM_CODE_END(__x86_return_thunk)