On Tue, 17 Dec 2024 at 10:21, David Woodhouse <dw...@infradead.org> wrote: > > On 17 December 2024 09:49:04 CET, Ard Biesheuvel <a...@kernel.org> wrote: > >On Tue, 17 Dec 2024 at 00:37, David Woodhouse <dw...@infradead.org> wrote: > >> > >> From: David Woodhouse <d...@amazon.co.uk> > >> > >> Both i386 and x86_64 now copy the relocate_kernel function into the control > >> page and execute it from there, using an open-coded function pointer. > >> > >> Use a typedef for it instead. > >> > >> Signed-off-by: David Woodhouse <d...@amazon.co.uk> > >> --- > >> arch/x86/include/asm/kexec.h | 26 +++++++++++++------------- > >> arch/x86/kernel/machine_kexec_32.c | 7 +------ > >> arch/x86/kernel/machine_kexec_64.c | 6 +----- > >> 3 files changed, 15 insertions(+), 24 deletions(-) > >> > >> diff --git a/arch/x86/include/asm/kexec.h b/arch/x86/include/asm/kexec.h > >> index 48e4f44f794f..8ad187462b68 100644 > >> --- a/arch/x86/include/asm/kexec.h > >> +++ b/arch/x86/include/asm/kexec.h > >> @@ -111,21 +111,21 @@ static inline void crash_setup_regs(struct pt_regs > >> *newregs, > >> } > >> > >> #ifdef CONFIG_X86_32 > >> -asmlinkage unsigned long > >> -relocate_kernel(unsigned long indirection_page, > >> - unsigned long control_page, > >> - unsigned long start_address, > >> - unsigned int has_pae, > >> - unsigned int preserve_context); > >> +typedef asmlinkage unsigned long > >> +relocate_kernel_fn(unsigned long indirection_page, > >> + unsigned long control_page, > >> + unsigned long start_address, > >> + unsigned int has_pae, > >> + unsigned int preserve_context); > > > >linkage is not part of the type. 'asmlinkage' is #define'd to the > >empty string today, so it doesn't matter, but better to omit it here. > > This is the i386 version. I thought ut was something like regparm(3) there? > > And... WTF? How is the calling convention not part of the fundamental type of > the function? If I have a pointer to such a function, using this typedef to > ensure we all share the same prototype, are you telling me all the users of > the typedef have to remember to tag that part on for themselves?
No. I am talking about linkage not the calling convention. Look at how __efiapi is used in the kernel if you would like to understand the difference.
