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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 08/12] powerpc/fsl_booke/kaslr: clear the original kernel if randomized
Date: Fri, 20 Sep 2019 17:45:42 +0800
Message-ID: <20190920094546.44948-9-yanaijie@huawei.com> (raw)
In-Reply-To: <20190920094546.44948-1-yanaijie@huawei.com>

The original kernel still exists in the memory, clear it now.

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/mm/mmu_decl.h           |  2 ++
 arch/powerpc/mm/nohash/fsl_booke.c   |  1 +
 arch/powerpc/mm/nohash/kaslr_booke.c | 11 +++++++++++
 3 files changed, 14 insertions(+)

diff --git a/arch/powerpc/mm/mmu_decl.h b/arch/powerpc/mm/mmu_decl.h
index a3a4937c0496..565731475a07 100644
--- a/arch/powerpc/mm/mmu_decl.h
+++ b/arch/powerpc/mm/mmu_decl.h
@@ -151,8 +151,10 @@ extern void loadcam_multi(int first_idx, int num, int tmp_idx);
 
 #ifdef CONFIG_RANDOMIZE_BASE
 void kaslr_early_init(void *dt_ptr, phys_addr_t size);
+void kaslr_late_init(void);
 #else
 static inline void kaslr_early_init(void *dt_ptr, phys_addr_t size) {}
+static inline void kaslr_late_init(void) {}
 #endif
 
 struct tlbcam {
diff --git a/arch/powerpc/mm/nohash/fsl_booke.c b/arch/powerpc/mm/nohash/fsl_booke.c
index 2dc27cf88add..b4eb06ceb189 100644
--- a/arch/powerpc/mm/nohash/fsl_booke.c
+++ b/arch/powerpc/mm/nohash/fsl_booke.c
@@ -269,6 +269,7 @@ notrace void __init relocate_init(u64 dt_ptr, phys_addr_t start)
 	kernstart_addr = start;
 	if (is_second_reloc) {
 		virt_phys_offset = PAGE_OFFSET - memstart_addr;
+		kaslr_late_init();
 		return;
 	}
 
diff --git a/arch/powerpc/mm/nohash/kaslr_booke.c b/arch/powerpc/mm/nohash/kaslr_booke.c
index 7b238fc2c8a9..aa1b60c782e7 100644
--- a/arch/powerpc/mm/nohash/kaslr_booke.c
+++ b/arch/powerpc/mm/nohash/kaslr_booke.c
@@ -381,3 +381,14 @@ notrace void __init kaslr_early_init(void *dt_ptr, phys_addr_t size)
 
 	reloc_kernel_entry(dt_ptr, kernstart_virt_addr);
 }
+
+void __init kaslr_late_init(void)
+{
+	/* If randomized, clear the original kernel */
+	if (kernstart_virt_addr != KERNELBASE) {
+		unsigned long kernel_sz;
+
+		kernel_sz = (unsigned long)_end - kernstart_virt_addr;
+		memzero_explicit((void *)KERNELBASE, kernel_sz);
+	}
+}
-- 
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 ` [PATCH v7 05/12] powerpc/fsl_booke/32: introduce reloc_kernel_entry() helper Jason Yan
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 ` Jason Yan [this message]
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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