| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Date: Mon, 10 Dec 2012 10:12:49 +0000
From: James Hogan <james.hogan@...tec.com>
To: Rusty Russell <rusty@...abs.org>
CC: Michal Marek <mmarek@...e.cz>, Takashi Iwai <tiwai@...e.de>,
David Howells <dhowells@...hat.com>,
<linux-kernel@...r.kernel.org>
Subject: Re: [PATCH 2/3] MODSIGN: Avoid using .incbin in C source
On 07/12/12 04:40, Rusty Russell wrote:
> Michal Marek <mmarek@...e.cz> writes:
>> It looks good, but looking at your patch, I just noticed that we have two
>> versions of the SYMBOL_PREFIX macro in the kernel now:
>>
>> scripts/Makefile.lib has had since some time
>>
>> ifdef CONFIG_SYMBOL_PREFIX
>> _sym_flags = -DSYMBOL_PREFIX=$(patsubst "%",%,$(CONFIG_SYMBOL_PREFIX))
>> _cpp_flags += $(_sym_flags)
>> _a_flags += $(_sym_flags)
>> endif
>>
>> while include/linux/kernel.h now has
>>
>> /* This helps us to avoid #ifdef CONFIG_SYMBOL_PREFIX */
>> #ifdef CONFIG_SYMBOL_PREFIX
>> #define SYMBOL_PREFIX CONFIG_SYMBOL_PREFIX
>> #else
>> #define SYMBOL_PREFIX ""
>> #endif
>
> What a mess! AFAICT there's one place which a non-string SYMBOL_PREFIX:
> include/asm-generic/vmlinux.lds.h
>
> So we do need it, and the only sane way seems to be via the cmdline and
> the shell usefully stripping quotes as we do.
>
> So I just took Takashi's do-it-all-in-asm fix, and removed this
> re-definition (we have the same thing, BTW, called
> MODULE_SYMBOL_PREFIX).
>
> I added a comment about the cmdline SYMBOL_PREFIX, too.
>
> Thanks,
> Rusty.
>
> From: Takashi Iwai <tiwai@...e.de>
> Subject: MODSIGN: Avoid using .incbin in C source
>
> Using the asm .incbin statement in C sources breaks any gcc wrapper which
> assumes that preprocessed C source is self-contained. Use a separate .S
> file to include the siging key and certificate.
>
> [ This means we no longer need SYMBOL_PREFIX which is defined in kernel.h
> from cbdbf2abb7844548a7d7a6a2ae7af6b6fbcea401, so I removed it -- RR ]
>
> Tested-by: Michal Marek <mmarek@...e.cz>
> Signed-off-by: Takashi Iwai <tiwai@...e.de>
> Signed-off-by: Rusty Russell <rusty@...tcorp.com.au>
Looks good to me.
Acked-by: James Hogan <james.hogan@...tec.com>
Thanks
James
> diff --git a/include/linux/kernel.h b/include/linux/kernel.h
> index 7d8dfc7..a123b13 100644
> --- a/include/linux/kernel.h
> +++ b/include/linux/kernel.h
> @@ -701,13 +701,6 @@ static inline void ftrace_dump(enum ftrace_dump_mode oops_dump_mode) { }
> #define COMPACTION_BUILD 0
> #endif
>
> -/* This helps us to avoid #ifdef CONFIG_SYMBOL_PREFIX */
> -#ifdef CONFIG_SYMBOL_PREFIX
> -#define SYMBOL_PREFIX CONFIG_SYMBOL_PREFIX
> -#else
> -#define SYMBOL_PREFIX ""
> -#endif
> -
> /* Rebuild everything on CONFIG_FTRACE_MCOUNT_RECORD */
> #ifdef CONFIG_FTRACE_MCOUNT_RECORD
> # define REBUILD_DUE_TO_FTRACE_MCOUNT_RECORD
> diff --git a/kernel/Makefile b/kernel/Makefile
> index 86e3285..0bd9d43 100644
> --- a/kernel/Makefile
> +++ b/kernel/Makefile
> @@ -54,7 +54,7 @@ obj-$(CONFIG_DEBUG_SPINLOCK) += spinlock.o
> obj-$(CONFIG_PROVE_LOCKING) += spinlock.o
> obj-$(CONFIG_UID16) += uid16.o
> obj-$(CONFIG_MODULES) += module.o
> -obj-$(CONFIG_MODULE_SIG) += module_signing.o modsign_pubkey.o
> +obj-$(CONFIG_MODULE_SIG) += module_signing.o modsign_pubkey.o modsign_certificate.o
> obj-$(CONFIG_KALLSYMS) += kallsyms.o
> obj-$(CONFIG_BSD_PROCESS_ACCT) += acct.o
> obj-$(CONFIG_KEXEC) += kexec.o
> @@ -139,7 +139,7 @@ ifeq ($(CONFIG_MODULE_SIG),y)
> extra_certificates:
> touch $@
>
> -kernel/modsign_pubkey.o: signing_key.x509 extra_certificates
> +kernel/modsign_certificate.o: signing_key.x509 extra_certificates
>
> ###############################################################################
> #
> diff --git a/kernel/modsign_certificate.S b/kernel/modsign_certificate.S
> new file mode 100644
> index 0000000..246b4c6
> --- /dev/null
> +++ b/kernel/modsign_certificate.S
> @@ -0,0 +1,19 @@
> +/* SYMBOL_PREFIX defined on commandline from CONFIG_SYMBOL_PREFIX */
> +#ifndef SYMBOL_PREFIX
> +#define ASM_SYMBOL(sym) sym
> +#else
> +#define PASTE2(x,y) x##y
> +#define PASTE(x,y) PASTE2(x,y)
> +#define ASM_SYMBOL(sym) PASTE(SYMBOL_PREFIX, sym)
> +#endif
> +
> +#define GLOBAL(name) \
> + .globl ASM_SYMBOL(name); \
> + ASM_SYMBOL(name):
> +
> + .section ".init.data","aw"
> +
> +GLOBAL(modsign_certificate_list)
> + .incbin "signing_key.x509"
> + .incbin "extra_certificates"
> +GLOBAL(modsign_certificate_list_end)
> diff --git a/kernel/modsign_pubkey.c b/kernel/modsign_pubkey.c
> index 767e559..045504f 100644
> --- a/kernel/modsign_pubkey.c
> +++ b/kernel/modsign_pubkey.c
> @@ -20,12 +20,6 @@ struct key *modsign_keyring;
>
> extern __initdata const u8 modsign_certificate_list[];
> extern __initdata const u8 modsign_certificate_list_end[];
> -asm(".section .init.data,\"aw\"\n"
> - SYMBOL_PREFIX "modsign_certificate_list:\n"
> - ".incbin \"signing_key.x509\"\n"
> - ".incbin \"extra_certificates\"\n"
> - SYMBOL_PREFIX "modsign_certificate_list_end:"
> - );
>
> /*
> * We need to make sure ccache doesn't cache the .o file as it doesn't notice
>
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists