Re: [PATCH] Modules 3/3: Sort sections

Rusty Russell
2003-01-02T10:42:23Z

In message <20030101205404.B30272@twiddle.net> you write:
> On Thu, Jan 02, 2003 at 02:00:27PM +1100, Rusty Russell wrote:
> > + /* Find .plt and .pltinit sections */
>
> Typo.
>
> > +/* Make empty sections for module_frob_arch_sections to expand. */
> > +#ifdef MODULE
> > +asm(".section .plt,\"aws\",@nobits; .align 3; .previous");
> > +asm(".section .plt.init,\"aws\",@nobits; .align 3; .previous");
>
> Should use "ax", do make the plt sections executable,
> since the plt section contains code that branches.
> Additionally, this will place the .plt section next
> to .text, which improves icache usage, and minimizes
> the branch distance.

OK, and I've renamed it to .init.plt, too.

Thanks!
Rusty.
--
Anyone who quotes me in their sig is an idiot. -- Rusty Russell.

diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal linux-2.5.54/arch/ppc/kernel/module.c working-2.5.54-ppcfix/arch/ppc/kernel/module.c
--- linux-2.5.54/arch/ppc/kernel/module.c 2003-01-02 14:47:57.000000000 +1100
+++ working-2.5.54-ppcfix/arch/ppc/kernel/module.c 2003-01-02 21:46:31.000000000 +1100
@@ -108,15 +108,15 @@ int module_frob_arch_sections(Elf32_Ehdr
{
unsigned int i;

- /* Find .plt and .pltinit sections */
+ /* Find .plt and .init.plt sections */
for (i = 0; i < hdr->e_shnum; i++) {
- if (strcmp(secstrings + sechdrs[i].sh_name, ".plt.init") == 0)
+ if (strcmp(secstrings + sechdrs[i].sh_name, ".init.plt") == 0)
me->arch.init_plt_section = i;
else if (strcmp(secstrings + sechdrs[i].sh_name, ".plt") == 0)
me->arch.core_plt_section = i;
}
if (!me->arch.core_plt_section || !me->arch.init_plt_section) {
- printk("Module doesn't contain .plt or .plt.init sections.\n");
+ printk("Module doesn't contain .plt or .init.plt sections.\n");
return -ENOEXEC;
}

diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal linux-2.5.54/include/asm-ppc/module.h working-2.5.54-ppcfix/include/asm-ppc/module.h
--- linux-2.5.54/include/asm-ppc/module.h 2003-01-02 14:48:00.000000000 +1100
+++ working-2.5.54-ppcfix/include/asm-ppc/module.h 2003-01-02 21:46:38.000000000 +1100
@@ -28,7 +28,7 @@ struct mod_arch_specific

/* Make empty sections for module_frob_arch_sections to expand. */
#ifdef MODULE
-asm(".section .plt,\"aws\",@nobits; .align 3; .previous");
-asm(".section .plt.init,\"aws\",@nobits; .align 3; .previous");
+asm(".section .plt,\"ax\",@nobits; .align 3; .previous");
+asm(".section .init.plt,\"ax\",@nobits; .align 3; .previous");
#endif
#endif /* _ASM_PPC_MODULE_H */