Messages in this thread | | | From | Scott Wood <> | Date | Wed, 04 Mar 2020 15:49:21 -0600 | Subject | Re: [PATCH v3 4/6] powerpc/fsl_booke/64: do not clear the BSS for the second pass |
| |
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
| |