From: Christophe Leroy <christophe.leroy@c-s.fr> To: Jason Yan <yanaijie@huawei.com>, mpe@ellerman.id.au, linuxppc-dev@lists.ozlabs.org, diana.craciun@nxp.com, benh@kernel.crashing.org, paulus@samba.org, npiggin@gmail.com, keescook@chromium.org, kernel-hardening@lists.openwall.com Cc: linux-kernel@vger.kernel.org, wangkefeng.wang@huawei.com, yebin10@huawei.com, thunder.leizhen@huawei.com, jingxiangfeng@huawei.com, fanchengyang@huawei.com Subject: Re: [RFC PATCH 05/10] powerpc/fsl_booke/32: introduce reloc_kernel_entry() helper Date: Mon, 29 Jul 2019 13:08:08 +0200 Message-ID: <e4ccd015-a9c4-b0a6-e3ca-d37a04e29ec6@c-s.fr> (raw) In-Reply-To: <20190717080621.40424-6-yanaijie@huawei.com> Le 17/07/2019 à 10:06, Jason Yan a écrit : > Add a new helper reloc_kernel_entry() to jump back to the start of the > new kernel. After we put the new kernel in a randomized place we can use > this new helper to enter the kernel and begin to relocate again. > > Signed-off-by: Jason Yan <yanaijie@huawei.com> > 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_fsl_booke.S | 16 ++++++++++++++++ > arch/powerpc/mm/mmu_decl.h | 1 + > 2 files changed, 17 insertions(+) > > diff --git a/arch/powerpc/kernel/head_fsl_booke.S b/arch/powerpc/kernel/head_fsl_booke.S > index a57d44638031..ce40f96dae20 100644 > --- a/arch/powerpc/kernel/head_fsl_booke.S > +++ b/arch/powerpc/kernel/head_fsl_booke.S > @@ -1144,6 +1144,22 @@ _GLOBAL(create_tlb_entry) > sync > blr > > +/* > + * Return to the start of the relocated kernel and run again > + * r3 - virtual address of fdt > + * r4 - entry of the kernel > + */ > +_GLOBAL(reloc_kernel_entry) > + mfmsr r7 > + li r8,(MSR_IS | MSR_DS) > + andc r7,r7,r8 Instead of the li/andc, what about the following: rlwinm r7, r7, 0, ~(MSR_IS | MSR_DS) > + > + mtspr SPRN_SRR0,r4 > + mtspr SPRN_SRR1,r7 > + isync > + sync > + rfi Are the isync/sync really necessary ? AFAIK, rfi is context synchronising. > + > /* > * Create a tlb entry with the same effective and physical address as > * the tlb entry used by the current running code. But set the TS to 1. > diff --git a/arch/powerpc/mm/mmu_decl.h b/arch/powerpc/mm/mmu_decl.h > index d7737cf97cee..dae8e9177574 100644 > --- a/arch/powerpc/mm/mmu_decl.h > +++ b/arch/powerpc/mm/mmu_decl.h > @@ -143,6 +143,7 @@ extern void adjust_total_lowmem(void); > extern int switch_to_as1(void); > extern void restore_to_as0(int esel, int offset, void *dt_ptr, int bootcpu); > extern void create_tlb_entry(phys_addr_t phys, unsigned long virt, int entry); > +extern void reloc_kernel_entry(void *fdt, int addr); No new 'extern' please, see https://openpower.xyz/job/snowpatch/job/snowpatch-linux-checkpatch/8125//artifact/linux/checkpatch.log > #endif > extern void loadcam_entry(unsigned int index); > extern void loadcam_multi(int first_idx, int num, int tmp_idx); > Christophe
next prev parent reply index Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top 2019-07-17 8:06 [RFC PATCH 00/10] implement KASLR for powerpc/fsl_booke/32 Jason Yan 2019-07-17 8:06 ` [RFC PATCH 01/10] powerpc: unify definition of M_IF_NEEDED Jason Yan 2019-07-29 10:59 ` Christophe Leroy 2019-07-17 8:06 ` [RFC PATCH 02/10] powerpc: move memstart_addr and kernstart_addr to init-common.c Jason Yan 2019-07-29 11:00 ` Christophe Leroy 2019-07-29 14:31 ` Christoph Hellwig 2019-07-30 0:47 ` Jason Yan 2019-07-17 8:06 ` [RFC PATCH 03/10] powerpc: introduce kimage_vaddr to store the kernel base Jason Yan 2019-07-29 11:00 ` Christophe Leroy 2019-07-29 14:32 ` Christoph Hellwig 2019-07-17 8:06 ` [RFC PATCH 04/10] powerpc/fsl_booke/32: introduce create_tlb_entry() helper Jason Yan 2019-07-29 11:05 ` Christophe Leroy 2019-07-29 13:26 ` Jason Yan 2019-07-17 8:06 ` [RFC PATCH 05/10] powerpc/fsl_booke/32: introduce reloc_kernel_entry() helper Jason Yan 2019-07-29 11:08 ` Christophe Leroy [this message] 2019-07-29 13:35 ` Jason Yan 2019-07-17 8:06 ` [RFC PATCH 06/10] powerpc/fsl_booke/32: implement KASLR infrastructure Jason Yan 2019-07-29 11:16 ` Christophe Leroy 2019-07-17 8:06 ` [RFC PATCH 07/10] powerpc/fsl_booke/32: randomize the kernel image offset Jason Yan 2019-07-29 11:33 ` Christophe Leroy 2019-07-29 13:53 ` Jason Yan 2019-07-17 8:06 ` [RFC PATCH 08/10] powerpc/fsl_booke/kaslr: clear the original kernel if randomized Jason Yan 2019-07-29 11:19 ` Christophe Leroy 2019-07-29 13:43 ` Jason Yan 2019-07-17 8:06 ` [RFC PATCH 09/10] powerpc/fsl_booke/kaslr: support nokaslr cmdline parameter Jason Yan 2019-07-29 11:38 ` Christophe Leroy 2019-07-29 14:04 ` Jason Yan 2019-07-17 8:06 ` [RFC PATCH 10/10] powerpc/fsl_booke/kaslr: dump out kernel offset information on panic Jason Yan 2019-07-29 11:43 ` Christophe Leroy 2019-07-29 14:08 ` Jason Yan 2019-07-25 7:16 ` [RFC PATCH 00/10] implement KASLR for powerpc/fsl_booke/32 Jason Yan 2019-07-25 19:58 ` Kees Cook 2019-07-26 7:20 ` Jason Yan 2019-07-26 16:15 ` Kees Cook 2019-07-26 7:04 ` Diana Madalina Craciun 2019-07-26 7:26 ` Jason Yan 2019-07-29 14:30 ` Diana Madalina Craciun
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