On Wednesday 18 July 2012, David Howells wrote:
> Hi Rusty, Arnd,
>
> Here's a patch to asm-genericise the arch asm/module.h files. It allows four
> of them to be deleted outright. MIPS is the only weirdo of the bunch.
>
Good idea!
> commit 4ef65a8a753f6fee4436dfa369e7471d3496b3ae
> Author: David Howells <dhowells@xxxxxxxxxx>
> Date: Wed Jul 18 13:26:21 2012 +0100
>
> Make most arch asm/module.h files use asm-generic/module.h
>
> Use the mapping of Elf_[SPE]hdr, Elf_Sym, Elf_Dyn, Elf_Rel/Rela, ELF_R_TYPE()
> and ELF_R_SYM() to either the 32-bit version or the 64-bit version into
> asm-generic/module.h for all arches bar MIPS.
>
> Also, use the generic definition mod_arch_specific where possible.
>
> To this end, I've defined three new config bools:
>
> (*) HAVE_MOD_ARCH_SPECIFIC
>
> Arches define this if they don't want to use the empty generic
> mod_arch_specific struct.
The method I try to use for architectures overriding asm-generic definitions
is to make the architecture define the same symbol, like
#ifdef CONFIG_ARM_UNWIND
struct mod_arch_specific {
struct unwind_table *unwind[ARM_SEC_MAX];
};
#define mod_arch_specific mod_arch_specific
#endif
and then let the asm-generic version test that using
#ifndef mod_arch_specific
struct mod_arch_specific {};
#endif
> (*) MODULES_USE_RELA_ONLY
>
> Arches define this if their modules will only contain RELA records (and
> not REL records). This causes the Elf_Rel mapping not to be emitted.
>
> (*) MODULES_USE_REL_ONLY
>
> Arches define this if their modules will only contain REL records (and
> not RELA records). This causes the Elf_Rela mapping not to be emitted.
I believe all architectures have either one or the other, but never both or neither
of the two, right? If so, we only need one symbol here.
We also introduced
int __weak apply_relocate(Elf_Shdr *sechdrs,
const char *strtab,
unsigned int symindex,
unsigned int relsec,
struct module *me)
{
pr_err("module %s: REL relocation unsupported\n", me->name);
return -ENOEXEC;
}
int __weak apply_relocate_add(Elf_Shdr *sechdrs,
const char *strtab,
unsigned int symindex,
unsigned int relsec,
struct module *me)
{
pr_err("module %s: RELA relocation unsupported\n", me->name);
return -ENOEXEC;
}
some time back to provide a default so architectures no longer need
to provide the apply_relocate function for both cases. If we have the
Kconfig symbol you introduce, we can turn this into an nice inline
function and do
#ifdef CONFIG_MODULES_USE_RELA_ONLY
static inline int __weak apply_relocate(Elf_Shdr *sechdrs,
const char *strtab,
unsigned int symindex,
unsigned int relsec,
struct module *me)
{
pr_err("module %s: REL relocation unsupported\n", me->name);
return -ENOEXEC;
}
int __weak apply_relocate_add(Elf_Shdr *sechdrs,
const char *strtab,
unsigned int symindex,
unsigned int relsec,
struct module *me);
#else
int __weak apply_relocate(Elf_Shdr *sechdrs,
const char *strtab,
unsigned int symindex,
unsigned int relsec,
struct module *me);
static inline int __weak apply_relocate_add(Elf_Shdr *sechdrs,
const char *strtab,
unsigned int symindex,
unsigned int relsec,
struct module *me)
{
pr_err("module %s: RELA relocation unsupported\n", me->name);
return -ENOEXEC;
}
#endif
and consequently kill off the remaining empty functions.
Arnd
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