From 61a73f5cd1a5794626d216cc56e20a1b195c5d0c Mon Sep 17 00:00:00 2001 From: Josh Poimboeuf Date: Wed, 17 Jul 2019 20:36:41 -0500 Subject: [PATCH] x86/head/64: Annotate start_cpu0() as non-callable After an objtool improvement, it complains about the fact that start_cpu0() jumps to code which has an LRET instruction. arch/x86/kernel/head_64.o: warning: objtool: .head.text+0xe4: unsupported instruction in callable function Technically, start_cpu0() is callable, but it acts nothing like a callable function. Prevent objtool from treating it like one by removing its ELF function annotation. Signed-off-by: Josh Poimboeuf Signed-off-by: Thomas Gleixner Acked-by: Peter Zijlstra (Intel) Link: https://lkml.kernel.org/r/6b1b4505fcb90571a55fa1b52d71fb458ca24454.1563413318.git.jpoimboe@redhat.com --- arch/x86/kernel/head_64.S | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/x86/kernel/head_64.S b/arch/x86/kernel/head_64.S index bcd206c8ac90..66b4a7757397 100644 --- a/arch/x86/kernel/head_64.S +++ b/arch/x86/kernel/head_64.S @@ -253,10 +253,10 @@ END(secondary_startup_64) * start_secondary() via .Ljump_to_C_code. */ ENTRY(start_cpu0) - movq initial_stack(%rip), %rsp UNWIND_HINT_EMPTY + movq initial_stack(%rip), %rsp jmp .Ljump_to_C_code -ENDPROC(start_cpu0) +END(start_cpu0) #endif /* Both SMP bootup and ACPI suspend change these variables */ -- 2.45.2