From: Scott Wood <oss@buserror.net>
To: Jason Yan <yanaijie@huawei.com>,
mpe@ellerman.id.au, linuxppc-dev@lists.ozlabs.org,
diana.craciun@nxp.com, christophe.leroy@c-s.fr,
benh@kernel.crashing.org, paulus@samba.org, npiggin@gmail.com,
keescook@chromium.org, kernel-hardening@lists.openwall.com
Cc: linux-kernel@vger.kernel.org, zhaohongjiang@huawei.com
Subject: Re: [PATCH v3 4/6] powerpc/fsl_booke/64: do not clear the BSS for the second pass
Date: Wed, 04 Mar 2020 15:49:21 -0600 [thread overview]
Message-ID: <feda5c76f134b415d2f43b99b8d6880b9b4b1750.camel@buserror.net> (raw)
In-Reply-To: <20200206025825.22934-5-yanaijie@huawei.com>
On Thu, 2020-02-06 at 10:58 +0800, Jason Yan wrote:
> The BSS section has already cleared out in the first pass. No need to
> clear it again. This can save some time when booting with KASLR
> enabled.
>
> Signed-off-by: Jason Yan <yanaijie@huawei.com>
> Cc: Scott Wood <oss@buserror.net>
> Cc: Diana Craciun <diana.craciun@nxp.com>
> Cc: Michael Ellerman <mpe@ellerman.id.au>
> Cc: Christophe Leroy <christophe.leroy@c-s.fr>
> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
> Cc: Paul Mackerras <paulus@samba.org>
> Cc: Nicholas Piggin <npiggin@gmail.com>
> Cc: Kees Cook <keescook@chromium.org>
> ---
> arch/powerpc/kernel/head_64.S | 7 +++++++
> 1 file changed, 7 insertions(+)
>
> diff --git a/arch/powerpc/kernel/head_64.S b/arch/powerpc/kernel/head_64.S
> index 744624140fb8..8c644e7c3eaf 100644
> --- a/arch/powerpc/kernel/head_64.S
> +++ b/arch/powerpc/kernel/head_64.S
> @@ -914,6 +914,13 @@ start_here_multiplatform:
> bl relative_toc
> tovirt(r2,r2)
>
> + /* Do not clear the BSS for the second pass if randomized */
> + LOAD_REG_ADDR(r3, kernstart_virt_addr)
> + lwz r3,0(r3)
> + LOAD_REG_IMMEDIATE(r4, KERNELBASE)
> + cmpw r3,r4
> + bne 4f
These are 64-bit values.
-Scott
next prev parent reply other threads:[~2020-03-04 21:49 UTC|newest]
Thread overview: 45+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-06 2:58 [PATCH v3 0/6] implement KASLR for powerpc/fsl_booke/64 Jason Yan
2020-02-06 2:58 ` [PATCH v3 1/6] powerpc/fsl_booke/kaslr: refactor kaslr_legal_offset() and kaslr_early_init() Jason Yan
2020-02-20 13:40 ` Christophe Leroy
2020-02-26 2:11 ` Jason Yan
2020-02-06 2:58 ` [PATCH v3 2/6] powerpc/fsl_booke/64: introduce reloc_kernel_entry() helper Jason Yan
2020-02-20 13:41 ` Christophe Leroy
2020-02-06 2:58 ` [PATCH v3 3/6] powerpc/fsl_booke/64: implement KASLR for fsl_booke64 Jason Yan
2020-02-20 13:48 ` Christophe Leroy
2020-02-26 2:40 ` Jason Yan
2020-02-26 3:33 ` Jason Yan
2020-02-26 5:04 ` [RFC PATCH] Use IS_ENABLED() instead of #ifdefs Christophe Leroy
2020-02-26 6:26 ` Jason Yan
2020-02-26 5:10 ` [PATCH v3 3/6] powerpc/fsl_booke/64: implement KASLR for fsl_booke64 Christophe Leroy
2020-02-26 5:08 ` Christophe Leroy
2020-03-04 21:44 ` Scott Wood
2020-03-05 2:32 ` Jason Yan
2020-02-06 2:58 ` [PATCH v3 4/6] powerpc/fsl_booke/64: do not clear the BSS for the second pass Jason Yan
2020-03-04 21:49 ` Scott Wood [this message]
2020-03-05 3:14 ` Jason Yan
2020-02-06 2:58 ` [PATCH v3 5/6] powerpc/fsl_booke/64: clear the original kernel if randomized Jason Yan
2020-02-20 13:49 ` Christophe Leroy
2020-02-26 2:44 ` Jason Yan
2020-03-04 21:53 ` Scott Wood
2020-03-05 3:20 ` Jason Yan
2020-02-06 2:58 ` [PATCH v3 6/6] powerpc/fsl_booke/kaslr: rename kaslr-booke32.rst to kaslr-booke.rst and add 64bit part Jason Yan
2020-02-20 13:50 ` Christophe Leroy
2020-02-26 2:46 ` Jason Yan
2020-02-13 3:00 ` [PATCH v3 0/6] implement KASLR for powerpc/fsl_booke/64 Jason Yan
2020-02-20 3:33 ` Jason Yan
2020-02-26 7:16 ` Daniel Axtens
2020-02-26 8:18 ` Jason Yan
2020-02-26 11:41 ` Daniel Axtens
2020-02-27 1:55 ` Jason Yan
2020-02-28 5:53 ` Scott Wood
2020-02-28 6:47 ` Jason Yan
2020-02-29 4:28 ` Scott Wood
2020-02-29 7:27 ` Jason Yan
2020-02-29 22:54 ` Scott Wood
2020-03-02 2:17 ` Jason Yan
2020-03-02 3:24 ` Scott Wood
2020-03-02 7:12 ` Jason Yan
2020-03-02 8:47 ` Scott Wood
2020-03-02 9:37 ` Jason Yan
2020-03-04 21:21 ` Scott Wood
2020-03-05 3:22 ` Jason Yan
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