[PATCH v2 03/11] x86/head: Mark *_start_kernel() __noreturn

From: Josh Poimboeuf
Date: Wed Apr 12 2023 - 19:50:14 EST


Now that start_kernel() is __noreturn, mark its chain of callers
__noreturn.

Signed-off-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
---
arch/x86/include/asm/setup.h | 6 +++---
arch/x86/kernel/head32.c | 2 +-
arch/x86/kernel/head64.c | 4 ++--
tools/objtool/check.c | 2 ++
4 files changed, 8 insertions(+), 6 deletions(-)

diff --git a/arch/x86/include/asm/setup.h b/arch/x86/include/asm/setup.h
index f37cbff7354c..f3495623ac99 100644
--- a/arch/x86/include/asm/setup.h
+++ b/arch/x86/include/asm/setup.h
@@ -125,11 +125,11 @@ void clear_bss(void);

#ifdef __i386__

-asmlinkage void __init i386_start_kernel(void);
+asmlinkage void __init __noreturn i386_start_kernel(void);

#else
-asmlinkage void __init x86_64_start_kernel(char *real_mode);
-asmlinkage void __init x86_64_start_reservations(char *real_mode_data);
+asmlinkage void __init __noreturn x86_64_start_kernel(char *real_mode);
+asmlinkage void __init __noreturn x86_64_start_reservations(char *real_mode_data);

#endif /* __i386__ */
#endif /* _SETUP */
diff --git a/arch/x86/kernel/head32.c b/arch/x86/kernel/head32.c
index ec6fefbfd3c0..10c27b4261eb 100644
--- a/arch/x86/kernel/head32.c
+++ b/arch/x86/kernel/head32.c
@@ -29,7 +29,7 @@ static void __init i386_default_early_setup(void)
x86_init.mpparse.setup_ioapic_ids = setup_ioapic_ids_from_mpc;
}

-asmlinkage __visible void __init i386_start_kernel(void)
+asmlinkage __visible void __init __noreturn i386_start_kernel(void)
{
/* Make sure IDT is set up before any exception happens */
idt_setup_early_handler();
diff --git a/arch/x86/kernel/head64.c b/arch/x86/kernel/head64.c
index 387e4b12e823..49f7629b17f7 100644
--- a/arch/x86/kernel/head64.c
+++ b/arch/x86/kernel/head64.c
@@ -471,7 +471,7 @@ static void __init copy_bootdata(char *real_mode_data)
sme_unmap_bootdata(real_mode_data);
}

-asmlinkage __visible void __init x86_64_start_kernel(char * real_mode_data)
+asmlinkage __visible void __init __noreturn x86_64_start_kernel(char * real_mode_data)
{
/*
* Build-time sanity checks on the kernel image and module
@@ -537,7 +537,7 @@ asmlinkage __visible void __init x86_64_start_kernel(char * real_mode_data)
x86_64_start_reservations(real_mode_data);
}

-void __init x86_64_start_reservations(char *real_mode_data)
+void __init __noreturn x86_64_start_reservations(char *real_mode_data)
{
/* version is always not zero if it is copied */
if (!boot_params.hdr.version)
diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index a6f9a4aeb77b..4e89342dd8fb 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -225,6 +225,8 @@ static bool __dead_end_function(struct objtool_file *file, struct symbol *func,
"start_kernel",
"stop_this_cpu",
"usercopy_abort",
+ "x86_64_start_kernel",
+ "x86_64_start_reservations",
"xen_cpu_bringup_again",
"xen_start_kernel",
};
--
2.39.2