在 2020/3/5 5:49, Scott Wood 写道:
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 <yanai...@huawei.com>
Cc: Scott Wood <o...@buserror.net>
Cc: Diana Craciun <diana.crac...@nxp.com>
Cc: Michael Ellerman <m...@ellerman.id.au>
Cc: Christophe Leroy <christophe.le...@c-s.fr>
Cc: Benjamin Herrenschmidt <b...@kernel.crashing.org>
Cc: Paul Mackerras <pau...@samba.org>
Cc: Nicholas Piggin <npig...@gmail.com>
Cc: Kees Cook <keesc...@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.
Oh yes, will fix. Thanks.
-Scott
.
