[tip: x86/urgent] x86/alternative: Remove noinline from __ibt_endbr_seal[_end]() stubs

From: tip-bot2 for Miaohe Lin
Date: Mon Dec 05 2022 - 05:59:38 EST


The following commit has been merged into the x86/urgent branch of tip:

Commit-ID: 023e59d4cee91dd3ca811eb01db2c5fb9f783dc2
Gitweb: https://git.kernel.org/tip/023e59d4cee91dd3ca811eb01db2c5fb9f783dc2
Author: Miaohe Lin <linmiaohe@xxxxxxxxxx>
AuthorDate: Tue, 11 Oct 2022 19:38:03 +08:00
Committer: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CommitterDate: Fri, 02 Dec 2022 12:54:43 +01:00

x86/alternative: Remove noinline from __ibt_endbr_seal[_end]() stubs

Due to the explicit 'noinline' GCC-7.3 is not able to optimize away the
argument setup of:

apply_ibt_endbr(__ibt_endbr_seal, __ibt_enbr_seal_end);

even when X86_KERNEL_IBT=n and the function is an empty stub, which leads
to link errors due to missing __ibt_endbr_seal* symbols:

ld: arch/x86/kernel/alternative.o: in function `alternative_instructions':
alternative.c:(.init.text+0x15d): undefined reference to `__ibt_endbr_seal_end'
ld: alternative.c:(.init.text+0x164): undefined reference to `__ibt_endbr_seal'

Remove the explicit 'noinline' to help gcc optimize them away.

Signed-off-by: Miaohe Lin <linmiaohe@xxxxxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20221011113803.956808-1-linmiaohe@xxxxxxxxxx
---
arch/x86/kernel/alternative.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c
index 5cadcea..beaf9fc 100644
--- a/arch/x86/kernel/alternative.c
+++ b/arch/x86/kernel/alternative.c
@@ -624,7 +624,7 @@ void __init_or_module noinline apply_ibt_endbr(s32 *start, s32 *end)

#else

-void __init_or_module noinline apply_ibt_endbr(s32 *start, s32 *end) { }
+void __init_or_module apply_ibt_endbr(s32 *start, s32 *end) { }

#endif /* CONFIG_X86_KERNEL_IBT */