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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>, <zhaohongjiang@huawei.com>,
	<oss@buserror.net>, Jason Yan <yanaijie@huawei.com>
Subject: [PATCH v7 05/12] powerpc/fsl_booke/32: introduce reloc_kernel_entry() helper
Date: Fri, 20 Sep 2019 17:45:39 +0800
Message-ID: <20190920094546.44948-6-yanaijie@huawei.com> (raw)
In-Reply-To: <20190920094546.44948-1-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>
Reviewed-by: Christophe Leroy <christophe.leroy@c-s.fr>
Reviewed-by: Diana Craciun <diana.craciun@nxp.com>
Tested-by: Diana Craciun <diana.craciun@nxp.com>
---
 arch/powerpc/kernel/head_fsl_booke.S | 13 +++++++++++++
 arch/powerpc/mm/mmu_decl.h           |  1 +
 2 files changed, 14 insertions(+)

diff --git a/arch/powerpc/kernel/head_fsl_booke.S b/arch/powerpc/kernel/head_fsl_booke.S
index 8c1928176ffe..d9f599b01ff1 100644
--- a/arch/powerpc/kernel/head_fsl_booke.S
+++ b/arch/powerpc/kernel/head_fsl_booke.S
@@ -1149,6 +1149,19 @@ _GLOBAL(create_kaslr_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
+	rlwinm	r7, r7, 0, ~(MSR_IS | MSR_DS)
+
+	mtspr	SPRN_SRR0,r4
+	mtspr	SPRN_SRR1,r7
+	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 a492ece08f64..55e86a0bf562 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);
 void create_kaslr_tlb_entry(int entry, unsigned long virt, phys_addr_t phys);
+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: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-09-20  9:45 [PATCH v7 00/12] implement KASLR for powerpc/fsl_booke/32 Jason Yan
2019-09-20  9:45 ` [PATCH v7 01/12] powerpc: unify definition of M_IF_NEEDED Jason Yan
2019-09-20  9:45 ` [PATCH v7 02/12] powerpc: move memstart_addr and kernstart_addr to init-common.c Jason Yan
2019-09-20  9:45 ` [PATCH v7 03/12] powerpc: introduce kernstart_virt_addr to store the kernel base Jason Yan
2019-09-20  9:45 ` [PATCH v7 04/12] powerpc/fsl_booke/32: introduce create_kaslr_tlb_entry() helper Jason Yan
2019-09-20  9:45 ` Jason Yan [this message]
2019-09-20  9:45 ` [PATCH v7 06/12] powerpc/fsl_booke/32: implement KASLR infrastructure Jason Yan
2019-09-20  9:45 ` [PATCH v7 07/12] powerpc/fsl_booke/32: randomize the kernel image offset Jason Yan
2019-09-20  9:45 ` [PATCH v7 08/12] powerpc/fsl_booke/kaslr: clear the original kernel if randomized Jason Yan
2019-09-20  9:45 ` [PATCH v7 09/12] powerpc/fsl_booke/kaslr: support nokaslr cmdline parameter Jason Yan
2019-09-20  9:45 ` [PATCH v7 10/12] powerpc/fsl_booke/kaslr: dump out kernel offset information on panic Jason Yan
2019-09-20  9:45 ` [PATCH v7 11/12] powerpc/fsl_booke/kaslr: export offset in VMCOREINFO ELF notes Jason Yan
2019-09-20  9:45 ` [PATCH v7 12/12] powerpc/fsl_booke/32: Document KASLR implementation Jason Yan
2019-09-24  5:52 ` [PATCH v7 00/12] implement KASLR for powerpc/fsl_booke/32 Jason Yan
2019-10-09  6:10   ` Jason Yan
2019-10-09  7:13     ` Scott Wood
2019-10-09  8:41       ` Jason Yan
2019-10-09 18:46         ` Scott Wood
2019-10-21  3:34           ` Jason Yan
2019-10-22 23:22             ` Scott Wood

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