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From: Jason Yan <yanaijie@huawei.com>
To: <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>, <wangkefeng.wang@huawei.com>,
	<yebin10@huawei.com>, <thunder.leizhen@huawei.com>,
	<jingxiangfeng@huawei.com>, <fanchengyang@huawei.com>,
	Jason Yan <yanaijie@huawei.com>
Subject: [RFC PATCH 05/10] powerpc/fsl_booke/32: introduce reloc_kernel_entry() helper
Date: Wed, 17 Jul 2019 16:06:16 +0800
Message-ID: <20190717080621.40424-6-yanaijie@huawei.com> (raw)
In-Reply-To: <20190717080621.40424-1-yanaijie@huawei.com>

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
+
+	mtspr	SPRN_SRR0,r4
+	mtspr	SPRN_SRR1,r7
+	isync
+	sync
+	rfi
+
 /*
  * 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);
 #endif
 extern void loadcam_entry(unsigned int index);
 extern void loadcam_multi(int first_idx, int num, int tmp_idx);
-- 
2.17.2


  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 ` Jason Yan [this message]
2019-07-29 11:08   ` [RFC PATCH 05/10] powerpc/fsl_booke/32: introduce reloc_kernel_entry() helper Christophe Leroy
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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