Re: [PATCH v2 02/13] powerpc: Rename 'funcaddr' to 'addr' in 'struct ppc64_opd_entry'

Nicholas Piggin
2021-10-15T06:01:26Z

Excerpts from Christophe Leroy's message of October 14, 2021 3:49 pm:
> There are three architectures with function descriptors, try to
> have common names for the address they contain in order to
> refactor some functions into generic functions later.
>
> powerpc has 'funcaddr'
> ia64 has 'ip'
> parisc has 'addr'
>
> Vote for 'addr' and update 'struct ppc64_opd_entry' accordingly.

It is the "address of the entry point of the function" according to
powerpc ELF spec, so addr seems fine.

Reviewed-by: Nicholas Piggin <npiggin@gmail.com>

>
> Reviewed-by: Kees Cook <keescook@chromium.org>
> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
> ---
> arch/powerpc/include/asm/elf.h | 2 +-
> arch/powerpc/include/asm/sections.h | 2 +-
> arch/powerpc/kernel/module_64.c | 6 +++---
> 3 files changed, 5 insertions(+), 5 deletions(-)
>
> diff --git a/arch/powerpc/include/asm/elf.h b/arch/powerpc/include/asm/elf.h
> index a4406714c060..bb0f278f9ed4 100644
> --- a/arch/powerpc/include/asm/elf.h
> +++ b/arch/powerpc/include/asm/elf.h
> @@ -178,7 +178,7 @@ void relocate(unsigned long final_address);
>
> /* There's actually a third entry here, but it's unused */
> struct ppc64_opd_entry {
> - unsigned long funcaddr;
> + unsigned long addr;
> unsigned long r2;
> };
>
> diff --git a/arch/powerpc/include/asm/sections.h b/arch/powerpc/include/asm/sections.h
> index 6e4af4492a14..32e7035863ac 100644
> --- a/arch/powerpc/include/asm/sections.h
> +++ b/arch/powerpc/include/asm/sections.h
> @@ -77,7 +77,7 @@ static inline void *dereference_function_descriptor(void *ptr)
> struct ppc64_opd_entry *desc = ptr;
> void *p;
>
> - if (!get_kernel_nofault(p, (void *)&desc->funcaddr))
> + if (!get_kernel_nofault(p, (void *)&desc->addr))
> ptr = p;
> return ptr;
> }
> diff --git a/arch/powerpc/kernel/module_64.c b/arch/powerpc/kernel/module_64.c
> index 6baa676e7cb6..82908c9be627 100644
> --- a/arch/powerpc/kernel/module_64.c
> +++ b/arch/powerpc/kernel/module_64.c
> @@ -72,11 +72,11 @@ static func_desc_t func_desc(unsigned long addr)
> }
> static unsigned long func_addr(unsigned long addr)
> {
> - return func_desc(addr).funcaddr;
> + return func_desc(addr).addr;
> }
> static unsigned long stub_func_addr(func_desc_t func)
> {
> - return func.funcaddr;
> + return func.addr;
> }
> static unsigned int local_entry_offset(const Elf64_Sym *sym)
> {
> @@ -187,7 +187,7 @@ static int relacmp(const void *_x, const void *_y)
> static unsigned long get_stubs_size(const Elf64_Ehdr *hdr,
> const Elf64_Shdr *sechdrs)
> {
> - /* One extra reloc so it's always 0-funcaddr terminated */
> + /* One extra reloc so it's always 0-addr terminated */
> unsigned long relocs = 1;
> unsigned i;
>
> --
> 2.31.1
>
>
>