Re: [PATCH 2/2] module: workaround duplicate section names

[Amerigo Wang <xiyou.wangcong@gmail.com>]

On Wed, Aug 26, 2009 at 10:04:12PM +0930, Rusty Russell wrote:
>From: James Bottomley <James.Bottomley@HansenPartnership.com>
>
>(This patch leaves other problems, particularly the sections
> directory, but recent parisc toolchains seem to produce these
> modules and this prevents a crash and is a minimal change -- RR).
>
>The root cause is a duplicate section name (.text); is this legal?

AFAIK, yes.


>
>However, there's a problem with commit
>6d76013381ed28979cd122eb4b249a88b5e384fa in that if you fail to allocate
>a mod->sect_attrs (in this case it's null because of the duplication),
>it still gets used without checking in add_notes_attrs()
>
>This should fix it
>
>Signed-off-by: James Bottomley <James.Bottomley@suse.de>
>Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
>Tested-by: Helge Deller <deller@gmx.de>

Looks fine for me.

Reviewed-by: WANG Cong <xiyou.wangcong@gmail.com>

Thanks.


>---
>
>diff --git a/kernel/module.c b/kernel/module.c
>index fd14114..a703c49 100644
>--- a/kernel/module.c
>+++ b/kernel/module.c
>@@ -2353,7 +2353,8 @@ static noinline struct module *load_module(void __user *umod,
> 	if (err < 0)
> 		goto unlink;
> 	add_sect_attrs(mod, hdr->e_shnum, secstrings, sechdrs);
>-	add_notes_attrs(mod, hdr->e_shnum, secstrings, sechdrs);
>+	if (mod->sect_attrs)
>+		add_notes_attrs(mod, hdr->e_shnum, secstrings, sechdrs);
> 
> 	/* Get rid of temporary copy */
> 	vfree(hdr);
>--
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