[v2,06/10] powerpc/fsl_booke/32: implement KASLR infrastructure
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Message ID 20190730074225.39544-7-yanaijie@huawei.com
State New
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Series
  • implement KASLR for powerpc/fsl_booke/32
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Commit Message

Jason Yan July 30, 2019, 7:42 a.m. UTC
This patch add support to boot kernel from places other than KERNELBASE.
Since CONFIG_RELOCATABLE has already supported, what we need to do is
map or copy kernel to a proper place and relocate. Freescale Book-E
parts expect lowmem to be mapped by fixed TLB entries(TLB1). The TLB1
entries are not suitable to map the kernel directly in a randomized
region, so we chose to copy the kernel to a proper place and restart to
relocate.

The offset of the kernel was not randomized yet(a fixed 64M is set). We
will randomize it in the next patch.

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/Kconfig                          | 11 +++
 arch/powerpc/kernel/Makefile                  |  1 +
 arch/powerpc/kernel/early_32.c                |  2 +-
 arch/powerpc/kernel/fsl_booke_entry_mapping.S | 13 ++-
 arch/powerpc/kernel/head_fsl_booke.S          | 15 +++-
 arch/powerpc/kernel/kaslr_booke.c             | 84 +++++++++++++++++++
 arch/powerpc/mm/mmu_decl.h                    |  6 ++
 arch/powerpc/mm/nohash/fsl_booke.c            |  7 +-
 8 files changed, 126 insertions(+), 13 deletions(-)
 create mode 100644 arch/powerpc/kernel/kaslr_booke.c

Comments

Christophe Leroy July 30, 2019, 9:34 a.m. UTC | #1
Le 30/07/2019 à 09:42, Jason Yan a écrit :
> This patch add support to boot kernel from places other than KERNELBASE.
> Since CONFIG_RELOCATABLE has already supported, what we need to do is
> map or copy kernel to a proper place and relocate. Freescale Book-E
> parts expect lowmem to be mapped by fixed TLB entries(TLB1). The TLB1
> entries are not suitable to map the kernel directly in a randomized
> region, so we chose to copy the kernel to a proper place and restart to
> relocate.
> 
> The offset of the kernel was not randomized yet(a fixed 64M is set). We
> will randomize it in the next patch.
> 
> 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/Kconfig                          | 11 +++
>   arch/powerpc/kernel/Makefile                  |  1 +
>   arch/powerpc/kernel/early_32.c                |  2 +-
>   arch/powerpc/kernel/fsl_booke_entry_mapping.S | 13 ++-
>   arch/powerpc/kernel/head_fsl_booke.S          | 15 +++-
>   arch/powerpc/kernel/kaslr_booke.c             | 84 +++++++++++++++++++
>   arch/powerpc/mm/mmu_decl.h                    |  6 ++
>   arch/powerpc/mm/nohash/fsl_booke.c            |  7 +-
>   8 files changed, 126 insertions(+), 13 deletions(-)
>   create mode 100644 arch/powerpc/kernel/kaslr_booke.c
> 

[...]

> diff --git a/arch/powerpc/kernel/head_fsl_booke.S b/arch/powerpc/kernel/head_fsl_booke.S
> index 2083382dd662..a466c0f0d028 100644
> --- a/arch/powerpc/kernel/head_fsl_booke.S
> +++ b/arch/powerpc/kernel/head_fsl_booke.S
> @@ -155,6 +155,8 @@ _ENTRY(_start);
>    */
>   
>   _ENTRY(__early_start)
> +	LOAD_REG_ADDR_PIC(r20, kimage_vaddr)
> +	lwz     r20,0(r20)
>   
>   #define ENTRY_MAPPING_BOOT_SETUP
>   #include "fsl_booke_entry_mapping.S"
> @@ -277,8 +279,8 @@ set_ivor:
>   	ori	r6, r6, swapper_pg_dir@l
>   	lis	r5, abatron_pteptrs@h
>   	ori	r5, r5, abatron_pteptrs@l
> -	lis	r4, KERNELBASE@h
> -	ori	r4, r4, KERNELBASE@l
> +	lis     r3, kimage_vaddr@ha
> +	lwz     r4, kimage_vaddr@l(r3)
>   	stw	r5, 0(r4)	/* Save abatron_pteptrs at a fixed location */
>   	stw	r6, 0(r5)
>   
> @@ -1067,7 +1069,14 @@ __secondary_start:
>   	mr	r5,r25		/* phys kernel start */
>   	rlwinm	r5,r5,0,~0x3ffffff	/* aligned 64M */
>   	subf	r4,r5,r4	/* memstart_addr - phys kernel start */
> -	li	r5,0		/* no device tree */
> +#ifdef CONFIG_RANDOMIZE_BASE

Is that #ifdef really necessary ? Wouldn't it also work as expected when 
CONFIG_RANDOMIZE_BASE is not selected ?

> +	lis	r7,KERNELBASE@h
> +	ori	r7,r7,KERNELBASE@l
> +	cmpw	r20,r7		/* if kimage_vaddr != KERNELBASE, randomized */
> +	beq	2f
> +	li	r4,0
> +#endif
> +2:	li	r5,0		/* no device tree */
>   	li	r6,0		/* not boot cpu */
>   	bl	restore_to_as0
>   
> diff --git a/arch/powerpc/kernel/kaslr_booke.c b/arch/powerpc/kernel/kaslr_booke.c
> new file mode 100644
> index 000000000000..960bce4aa8b9
> --- /dev/null
> +++ b/arch/powerpc/kernel/kaslr_booke.c
> @@ -0,0 +1,84 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Copyright (C) 2019 Jason Yan <yanaijie@huawei.com>
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 as
> + * published by the Free Software Foundation.
> + */
> +
> +#include <linux/signal.h>
> +#include <linux/sched.h>
> +#include <linux/kernel.h>
> +#include <linux/errno.h>
> +#include <linux/string.h>
> +#include <linux/types.h>
> +#include <linux/ptrace.h>
> +#include <linux/mman.h>
> +#include <linux/mm.h>
> +#include <linux/swap.h>
> +#include <linux/stddef.h>
> +#include <linux/vmalloc.h>
> +#include <linux/init.h>
> +#include <linux/delay.h>
> +#include <linux/highmem.h>
> +#include <linux/memblock.h>
> +#include <asm/pgalloc.h>
> +#include <asm/prom.h>
> +#include <asm/io.h>
> +#include <asm/mmu_context.h>
> +#include <asm/pgtable.h>
> +#include <asm/mmu.h>
> +#include <linux/uaccess.h>
> +#include <asm/smp.h>
> +#include <asm/machdep.h>
> +#include <asm/setup.h>
> +#include <asm/paca.h>
> +#include <mm/mmu_decl.h>
> +
> +extern int is_second_reloc;

Couldn't the above be a bool ?

> +
> +static unsigned long __init kaslr_choose_location(void *dt_ptr, phys_addr_t size,
> +						  unsigned long kernel_sz)
> +{
> +	/* return a fixed offset of 64M for now */
> +	return 0x4000000;

64 << 20 would maybe be more explicit than 0x4000000.

Or return SZ_64M ?

Christophe

> +}
> +
> +/*
> + * To see if we need to relocate the kernel to a random offset
> + * void *dt_ptr - address of the device tree
> + * phys_addr_t size - size of the first memory block
> + */
> +notrace void __init kaslr_early_init(void *dt_ptr, phys_addr_t size)
> +{
> +	unsigned long tlb_virt;
> +	phys_addr_t tlb_phys;
> +	unsigned long offset;
> +	unsigned long kernel_sz;
> +
> +	kernel_sz = (unsigned long)_end - KERNELBASE;
> +
> +	offset = kaslr_choose_location(dt_ptr, size, kernel_sz);
> +
> +	if (offset == 0)
> +		return;
> +
> +	kimage_vaddr += offset;
> +	kernstart_addr += offset;
> +
> +	is_second_reloc = 1;
> +
> +	if (offset >= SZ_64M) {
> +		tlb_virt = round_down(kimage_vaddr, SZ_64M);
> +		tlb_phys = round_down(kernstart_addr, SZ_64M);
> +
> +		/* Create kernel map to relocate in */
> +		create_tlb_entry(tlb_phys, tlb_virt, 1);
> +	}
> +
> +	/* Copy the kernel to it's new location and run */
> +	memcpy((void *)kimage_vaddr, (void *)KERNELBASE, kernel_sz);
> +
> +	reloc_kernel_entry(dt_ptr, kimage_vaddr);
> +}
> diff --git a/arch/powerpc/mm/mmu_decl.h b/arch/powerpc/mm/mmu_decl.h
> index 804da298beb3..9332772c8a66 100644
> --- a/arch/powerpc/mm/mmu_decl.h
> +++ b/arch/powerpc/mm/mmu_decl.h
> @@ -148,6 +148,12 @@ void reloc_kernel_entry(void *fdt, int addr);
>   extern void loadcam_entry(unsigned int index);
>   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);
> +#else
> +static inline void kaslr_early_init(void *dt_ptr, phys_addr_t size) {}
> +#endif
> +
>   struct tlbcam {
>   	u32	MAS0;
>   	u32	MAS1;
> diff --git a/arch/powerpc/mm/nohash/fsl_booke.c b/arch/powerpc/mm/nohash/fsl_booke.c
> index 556e3cd52a35..8d25a8dc965f 100644
> --- a/arch/powerpc/mm/nohash/fsl_booke.c
> +++ b/arch/powerpc/mm/nohash/fsl_booke.c
> @@ -263,7 +263,8 @@ void setup_initial_memory_limit(phys_addr_t first_memblock_base,
>   int __initdata is_second_reloc;
>   notrace void __init relocate_init(u64 dt_ptr, phys_addr_t start)
>   {
> -	unsigned long base = KERNELBASE;
> +	unsigned long base = kimage_vaddr;
> +	phys_addr_t size;
>   
>   	kernstart_addr = start;
>   	if (is_second_reloc) {
> @@ -291,7 +292,7 @@ notrace void __init relocate_init(u64 dt_ptr, phys_addr_t start)
>   	start &= ~0x3ffffff;
>   	base &= ~0x3ffffff;
>   	virt_phys_offset = base - start;
> -	early_get_first_memblock_info(__va(dt_ptr), NULL);
> +	early_get_first_memblock_info(__va(dt_ptr), &size);
>   	/*
>   	 * We now get the memstart_addr, then we should check if this
>   	 * address is the same as what the PAGE_OFFSET map to now. If
> @@ -316,6 +317,8 @@ notrace void __init relocate_init(u64 dt_ptr, phys_addr_t start)
>   		/* We should never reach here */
>   		panic("Relocation error");
>   	}
> +
> +	kaslr_early_init(__va(dt_ptr), size);
>   }
>   #endif
>   #endif
>
Jason Yan July 31, 2019, 2:03 a.m. UTC | #2
On 2019/7/30 17:34, Christophe Leroy wrote:
> 
> 
> Le 30/07/2019 à 09:42, Jason Yan a écrit :
>> This patch add support to boot kernel from places other than KERNELBASE.
>> Since CONFIG_RELOCATABLE has already supported, what we need to do is
>> map or copy kernel to a proper place and relocate. Freescale Book-E
>> parts expect lowmem to be mapped by fixed TLB entries(TLB1). The TLB1
>> entries are not suitable to map the kernel directly in a randomized
>> region, so we chose to copy the kernel to a proper place and restart to
>> relocate.
>>
>> The offset of the kernel was not randomized yet(a fixed 64M is set). We
>> will randomize it in the next patch.
>>
>> 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/Kconfig                          | 11 +++
>>   arch/powerpc/kernel/Makefile                  |  1 +
>>   arch/powerpc/kernel/early_32.c                |  2 +-
>>   arch/powerpc/kernel/fsl_booke_entry_mapping.S | 13 ++-
>>   arch/powerpc/kernel/head_fsl_booke.S          | 15 +++-
>>   arch/powerpc/kernel/kaslr_booke.c             | 84 +++++++++++++++++++
>>   arch/powerpc/mm/mmu_decl.h                    |  6 ++
>>   arch/powerpc/mm/nohash/fsl_booke.c            |  7 +-
>>   8 files changed, 126 insertions(+), 13 deletions(-)
>>   create mode 100644 arch/powerpc/kernel/kaslr_booke.c
>>
> 
> [...]
> 
>> diff --git a/arch/powerpc/kernel/head_fsl_booke.S 
>> b/arch/powerpc/kernel/head_fsl_booke.S
>> index 2083382dd662..a466c0f0d028 100644
>> --- a/arch/powerpc/kernel/head_fsl_booke.S
>> +++ b/arch/powerpc/kernel/head_fsl_booke.S
>> @@ -155,6 +155,8 @@ _ENTRY(_start);
>>    */
>>   _ENTRY(__early_start)
>> +    LOAD_REG_ADDR_PIC(r20, kimage_vaddr)
>> +    lwz     r20,0(r20)
>>   #define ENTRY_MAPPING_BOOT_SETUP
>>   #include "fsl_booke_entry_mapping.S"
>> @@ -277,8 +279,8 @@ set_ivor:
>>       ori    r6, r6, swapper_pg_dir@l
>>       lis    r5, abatron_pteptrs@h
>>       ori    r5, r5, abatron_pteptrs@l
>> -    lis    r4, KERNELBASE@h
>> -    ori    r4, r4, KERNELBASE@l
>> +    lis     r3, kimage_vaddr@ha
>> +    lwz     r4, kimage_vaddr@l(r3)
>>       stw    r5, 0(r4)    /* Save abatron_pteptrs at a fixed location */
>>       stw    r6, 0(r5)
>> @@ -1067,7 +1069,14 @@ __secondary_start:
>>       mr    r5,r25        /* phys kernel start */
>>       rlwinm    r5,r5,0,~0x3ffffff    /* aligned 64M */
>>       subf    r4,r5,r4    /* memstart_addr - phys kernel start */
>> -    li    r5,0        /* no device tree */
>> +#ifdef CONFIG_RANDOMIZE_BASE
> 
> Is that #ifdef really necessary ? Wouldn't it also work as expected when 
> CONFIG_RANDOMIZE_BASE is not selected ?
> 

Yes, it will also work if CONFIG_RANDOMIZE_BASE is not enabled. I can 
remove it.

>> +    lis    r7,KERNELBASE@h
>> +    ori    r7,r7,KERNELBASE@l
>> +    cmpw    r20,r7        /* if kimage_vaddr != KERNELBASE, 
>> randomized */
>> +    beq    2f
>> +    li    r4,0
>> +#endif
>> +2:    li    r5,0        /* no device tree */
>>       li    r6,0        /* not boot cpu */
>>       bl    restore_to_as0
>> diff --git a/arch/powerpc/kernel/kaslr_booke.c 
>> b/arch/powerpc/kernel/kaslr_booke.c
>> new file mode 100644
>> index 000000000000..960bce4aa8b9
>> --- /dev/null
>> +++ b/arch/powerpc/kernel/kaslr_booke.c
>> @@ -0,0 +1,84 @@
>> +// SPDX-License-Identifier: GPL-2.0-only
>> +/*
>> + * Copyright (C) 2019 Jason Yan <yanaijie@huawei.com>
>> + *
>> + * This program is free software; you can redistribute it and/or modify
>> + * it under the terms of the GNU General Public License version 2 as
>> + * published by the Free Software Foundation.
>> + */
>> +
>> +#include <linux/signal.h>
>> +#include <linux/sched.h>
>> +#include <linux/kernel.h>
>> +#include <linux/errno.h>
>> +#include <linux/string.h>
>> +#include <linux/types.h>
>> +#include <linux/ptrace.h>
>> +#include <linux/mman.h>
>> +#include <linux/mm.h>
>> +#include <linux/swap.h>
>> +#include <linux/stddef.h>
>> +#include <linux/vmalloc.h>
>> +#include <linux/init.h>
>> +#include <linux/delay.h>
>> +#include <linux/highmem.h>
>> +#include <linux/memblock.h>
>> +#include <asm/pgalloc.h>
>> +#include <asm/prom.h>
>> +#include <asm/io.h>
>> +#include <asm/mmu_context.h>
>> +#include <asm/pgtable.h>
>> +#include <asm/mmu.h>
>> +#include <linux/uaccess.h>
>> +#include <asm/smp.h>
>> +#include <asm/machdep.h>
>> +#include <asm/setup.h>
>> +#include <asm/paca.h>
>> +#include <mm/mmu_decl.h>
>> +
>> +extern int is_second_reloc;
> 
> Couldn't the above be a bool ?
> 

This variable is both used in C and assembly. Use int make it more 
explicit to compare it with 0 or 1 in assembly.

>> +
>> +static unsigned long __init kaslr_choose_location(void *dt_ptr, 
>> phys_addr_t size,
>> +                          unsigned long kernel_sz)
>> +{
>> +    /* return a fixed offset of 64M for now */
>> +    return 0x4000000;
> 
> 64 << 20 would maybe be more explicit than 0x4000000.
> 
> Or return SZ_64M ?
> 

SZ_64M would be good.

> Christophe
> 
>> +}
>> +
>> +/*
>> + * To see if we need to relocate the kernel to a random offset
>> + * void *dt_ptr - address of the device tree
>> + * phys_addr_t size - size of the first memory block
>> + */
>> +notrace void __init kaslr_early_init(void *dt_ptr, phys_addr_t size)
>> +{
>> +    unsigned long tlb_virt;
>> +    phys_addr_t tlb_phys;
>> +    unsigned long offset;
>> +    unsigned long kernel_sz;
>> +
>> +    kernel_sz = (unsigned long)_end - KERNELBASE;
>> +
>> +    offset = kaslr_choose_location(dt_ptr, size, kernel_sz);
>> +
>> +    if (offset == 0)
>> +        return;
>> +
>> +    kimage_vaddr += offset;
>> +    kernstart_addr += offset;
>> +
>> +    is_second_reloc = 1;
>> +
>> +    if (offset >= SZ_64M) {
>> +        tlb_virt = round_down(kimage_vaddr, SZ_64M);
>> +        tlb_phys = round_down(kernstart_addr, SZ_64M);
>> +
>> +        /* Create kernel map to relocate in */
>> +        create_tlb_entry(tlb_phys, tlb_virt, 1);
>> +    }
>> +
>> +    /* Copy the kernel to it's new location and run */
>> +    memcpy((void *)kimage_vaddr, (void *)KERNELBASE, kernel_sz);
>> +
>> +    reloc_kernel_entry(dt_ptr, kimage_vaddr);
>> +}
>> diff --git a/arch/powerpc/mm/mmu_decl.h b/arch/powerpc/mm/mmu_decl.h
>> index 804da298beb3..9332772c8a66 100644
>> --- a/arch/powerpc/mm/mmu_decl.h
>> +++ b/arch/powerpc/mm/mmu_decl.h
>> @@ -148,6 +148,12 @@ void reloc_kernel_entry(void *fdt, int addr);
>>   extern void loadcam_entry(unsigned int index);
>>   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);
>> +#else
>> +static inline void kaslr_early_init(void *dt_ptr, phys_addr_t size) {}
>> +#endif
>> +
>>   struct tlbcam {
>>       u32    MAS0;
>>       u32    MAS1;
>> diff --git a/arch/powerpc/mm/nohash/fsl_booke.c 
>> b/arch/powerpc/mm/nohash/fsl_booke.c
>> index 556e3cd52a35..8d25a8dc965f 100644
>> --- a/arch/powerpc/mm/nohash/fsl_booke.c
>> +++ b/arch/powerpc/mm/nohash/fsl_booke.c
>> @@ -263,7 +263,8 @@ void setup_initial_memory_limit(phys_addr_t 
>> first_memblock_base,
>>   int __initdata is_second_reloc;
>>   notrace void __init relocate_init(u64 dt_ptr, phys_addr_t start)
>>   {
>> -    unsigned long base = KERNELBASE;
>> +    unsigned long base = kimage_vaddr;
>> +    phys_addr_t size;
>>       kernstart_addr = start;
>>       if (is_second_reloc) {
>> @@ -291,7 +292,7 @@ notrace void __init relocate_init(u64 dt_ptr, 
>> phys_addr_t start)
>>       start &= ~0x3ffffff;
>>       base &= ~0x3ffffff;
>>       virt_phys_offset = base - start;
>> -    early_get_first_memblock_info(__va(dt_ptr), NULL);
>> +    early_get_first_memblock_info(__va(dt_ptr), &size);
>>       /*
>>        * We now get the memstart_addr, then we should check if this
>>        * address is the same as what the PAGE_OFFSET map to now. If
>> @@ -316,6 +317,8 @@ notrace void __init relocate_init(u64 dt_ptr, 
>> phys_addr_t start)
>>           /* We should never reach here */
>>           panic("Relocation error");
>>       }
>> +
>> +    kaslr_early_init(__va(dt_ptr), size);
>>   }
>>   #endif
>>   #endif
>>
> 
> .
>

Patch
diff mbox series

diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 77f6ebf97113..755378887912 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -548,6 +548,17 @@  config RELOCATABLE
 	  setting can still be useful to bootwrappers that need to know the
 	  load address of the kernel (eg. u-boot/mkimage).
 
+config RANDOMIZE_BASE
+	bool "Randomize the address of the kernel image"
+	depends on (FSL_BOOKE && FLATMEM && PPC32)
+	select RELOCATABLE
+	help
+	  Randomizes the virtual address at which the kernel image is
+	  loaded, as a security feature that deters exploit attempts
+	  relying on knowledge of the location of kernel internals.
+
+	  If unsure, say N.
+
 config RELOCATABLE_TEST
 	bool "Test relocatable kernel"
 	depends on (PPC64 && RELOCATABLE)
diff --git a/arch/powerpc/kernel/Makefile b/arch/powerpc/kernel/Makefile
index ea0c69236789..32f6c5b99307 100644
--- a/arch/powerpc/kernel/Makefile
+++ b/arch/powerpc/kernel/Makefile
@@ -106,6 +106,7 @@  extra-$(CONFIG_PPC_8xx)		:= head_8xx.o
 extra-y				+= vmlinux.lds
 
 obj-$(CONFIG_RELOCATABLE)	+= reloc_$(BITS).o
+obj-$(CONFIG_RANDOMIZE_BASE)	+= kaslr_booke.o
 
 obj-$(CONFIG_PPC32)		+= entry_32.o setup_32.o early_32.o
 obj-$(CONFIG_PPC64)		+= dma-iommu.o iommu.o
diff --git a/arch/powerpc/kernel/early_32.c b/arch/powerpc/kernel/early_32.c
index 3482118ffe76..fe8347cdc07d 100644
--- a/arch/powerpc/kernel/early_32.c
+++ b/arch/powerpc/kernel/early_32.c
@@ -32,5 +32,5 @@  notrace unsigned long __init early_init(unsigned long dt_ptr)
 
 	apply_feature_fixups();
 
-	return KERNELBASE + offset;
+	return kimage_vaddr + offset;
 }
diff --git a/arch/powerpc/kernel/fsl_booke_entry_mapping.S b/arch/powerpc/kernel/fsl_booke_entry_mapping.S
index de0980945510..6d2967673ac7 100644
--- a/arch/powerpc/kernel/fsl_booke_entry_mapping.S
+++ b/arch/powerpc/kernel/fsl_booke_entry_mapping.S
@@ -161,17 +161,16 @@  skpinv:	addi	r6,r6,1				/* Increment */
 	lis	r6,(MAS1_VALID|MAS1_IPROT)@h
 	ori	r6,r6,(MAS1_TSIZE(BOOK3E_PAGESZ_64M))@l
 	mtspr	SPRN_MAS1,r6
-	lis	r6,MAS2_VAL(PAGE_OFFSET, BOOK3E_PAGESZ_64M, M_IF_NEEDED)@h
-	ori	r6,r6,MAS2_VAL(PAGE_OFFSET, BOOK3E_PAGESZ_64M, M_IF_NEEDED)@l
-	mtspr	SPRN_MAS2,r6
+	lis     r6,MAS2_EPN_MASK(BOOK3E_PAGESZ_64M)@h
+	ori     r6,r6,MAS2_EPN_MASK(BOOK3E_PAGESZ_64M)@l
+	and     r6,r6,r20
+	ori	r6,r6,M_IF_NEEDED@l
+	mtspr   SPRN_MAS2,r6
 	mtspr	SPRN_MAS3,r8
 	tlbwe
 
 /* 7. Jump to KERNELBASE mapping */
-	lis	r6,(KERNELBASE & ~0xfff)@h
-	ori	r6,r6,(KERNELBASE & ~0xfff)@l
-	rlwinm	r7,r25,0,0x03ffffff
-	add	r6,r7,r6
+	mr	r6,r20
 
 #elif defined(ENTRY_MAPPING_KEXEC_SETUP)
 /*
diff --git a/arch/powerpc/kernel/head_fsl_booke.S b/arch/powerpc/kernel/head_fsl_booke.S
index 2083382dd662..a466c0f0d028 100644
--- a/arch/powerpc/kernel/head_fsl_booke.S
+++ b/arch/powerpc/kernel/head_fsl_booke.S
@@ -155,6 +155,8 @@  _ENTRY(_start);
  */
 
 _ENTRY(__early_start)
+	LOAD_REG_ADDR_PIC(r20, kimage_vaddr)
+	lwz     r20,0(r20)
 
 #define ENTRY_MAPPING_BOOT_SETUP
 #include "fsl_booke_entry_mapping.S"
@@ -277,8 +279,8 @@  set_ivor:
 	ori	r6, r6, swapper_pg_dir@l
 	lis	r5, abatron_pteptrs@h
 	ori	r5, r5, abatron_pteptrs@l
-	lis	r4, KERNELBASE@h
-	ori	r4, r4, KERNELBASE@l
+	lis     r3, kimage_vaddr@ha
+	lwz     r4, kimage_vaddr@l(r3)
 	stw	r5, 0(r4)	/* Save abatron_pteptrs at a fixed location */
 	stw	r6, 0(r5)
 
@@ -1067,7 +1069,14 @@  __secondary_start:
 	mr	r5,r25		/* phys kernel start */
 	rlwinm	r5,r5,0,~0x3ffffff	/* aligned 64M */
 	subf	r4,r5,r4	/* memstart_addr - phys kernel start */
-	li	r5,0		/* no device tree */
+#ifdef CONFIG_RANDOMIZE_BASE
+	lis	r7,KERNELBASE@h
+	ori	r7,r7,KERNELBASE@l
+	cmpw	r20,r7		/* if kimage_vaddr != KERNELBASE, randomized */
+	beq	2f
+	li	r4,0
+#endif
+2:	li	r5,0		/* no device tree */
 	li	r6,0		/* not boot cpu */
 	bl	restore_to_as0
 
diff --git a/arch/powerpc/kernel/kaslr_booke.c b/arch/powerpc/kernel/kaslr_booke.c
new file mode 100644
index 000000000000..960bce4aa8b9
--- /dev/null
+++ b/arch/powerpc/kernel/kaslr_booke.c
@@ -0,0 +1,84 @@ 
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2019 Jason Yan <yanaijie@huawei.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/signal.h>
+#include <linux/sched.h>
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/string.h>
+#include <linux/types.h>
+#include <linux/ptrace.h>
+#include <linux/mman.h>
+#include <linux/mm.h>
+#include <linux/swap.h>
+#include <linux/stddef.h>
+#include <linux/vmalloc.h>
+#include <linux/init.h>
+#include <linux/delay.h>
+#include <linux/highmem.h>
+#include <linux/memblock.h>
+#include <asm/pgalloc.h>
+#include <asm/prom.h>
+#include <asm/io.h>
+#include <asm/mmu_context.h>
+#include <asm/pgtable.h>
+#include <asm/mmu.h>
+#include <linux/uaccess.h>
+#include <asm/smp.h>
+#include <asm/machdep.h>
+#include <asm/setup.h>
+#include <asm/paca.h>
+#include <mm/mmu_decl.h>
+
+extern int is_second_reloc;
+
+static unsigned long __init kaslr_choose_location(void *dt_ptr, phys_addr_t size,
+						  unsigned long kernel_sz)
+{
+	/* return a fixed offset of 64M for now */
+	return 0x4000000;
+}
+
+/*
+ * To see if we need to relocate the kernel to a random offset
+ * void *dt_ptr - address of the device tree
+ * phys_addr_t size - size of the first memory block
+ */
+notrace void __init kaslr_early_init(void *dt_ptr, phys_addr_t size)
+{
+	unsigned long tlb_virt;
+	phys_addr_t tlb_phys;
+	unsigned long offset;
+	unsigned long kernel_sz;
+
+	kernel_sz = (unsigned long)_end - KERNELBASE;
+
+	offset = kaslr_choose_location(dt_ptr, size, kernel_sz);
+
+	if (offset == 0)
+		return;
+
+	kimage_vaddr += offset;
+	kernstart_addr += offset;
+
+	is_second_reloc = 1;
+
+	if (offset >= SZ_64M) {
+		tlb_virt = round_down(kimage_vaddr, SZ_64M);
+		tlb_phys = round_down(kernstart_addr, SZ_64M);
+
+		/* Create kernel map to relocate in */
+		create_tlb_entry(tlb_phys, tlb_virt, 1);
+	}
+
+	/* Copy the kernel to it's new location and run */
+	memcpy((void *)kimage_vaddr, (void *)KERNELBASE, kernel_sz);
+
+	reloc_kernel_entry(dt_ptr, kimage_vaddr);
+}
diff --git a/arch/powerpc/mm/mmu_decl.h b/arch/powerpc/mm/mmu_decl.h
index 804da298beb3..9332772c8a66 100644
--- a/arch/powerpc/mm/mmu_decl.h
+++ b/arch/powerpc/mm/mmu_decl.h
@@ -148,6 +148,12 @@  void reloc_kernel_entry(void *fdt, int addr);
 extern void loadcam_entry(unsigned int index);
 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);
+#else
+static inline void kaslr_early_init(void *dt_ptr, phys_addr_t size) {}
+#endif
+
 struct tlbcam {
 	u32	MAS0;
 	u32	MAS1;
diff --git a/arch/powerpc/mm/nohash/fsl_booke.c b/arch/powerpc/mm/nohash/fsl_booke.c
index 556e3cd52a35..8d25a8dc965f 100644
--- a/arch/powerpc/mm/nohash/fsl_booke.c
+++ b/arch/powerpc/mm/nohash/fsl_booke.c
@@ -263,7 +263,8 @@  void setup_initial_memory_limit(phys_addr_t first_memblock_base,
 int __initdata is_second_reloc;
 notrace void __init relocate_init(u64 dt_ptr, phys_addr_t start)
 {
-	unsigned long base = KERNELBASE;
+	unsigned long base = kimage_vaddr;
+	phys_addr_t size;
 
 	kernstart_addr = start;
 	if (is_second_reloc) {
@@ -291,7 +292,7 @@  notrace void __init relocate_init(u64 dt_ptr, phys_addr_t start)
 	start &= ~0x3ffffff;
 	base &= ~0x3ffffff;
 	virt_phys_offset = base - start;
-	early_get_first_memblock_info(__va(dt_ptr), NULL);
+	early_get_first_memblock_info(__va(dt_ptr), &size);
 	/*
 	 * We now get the memstart_addr, then we should check if this
 	 * address is the same as what the PAGE_OFFSET map to now. If
@@ -316,6 +317,8 @@  notrace void __init relocate_init(u64 dt_ptr, phys_addr_t start)
 		/* We should never reach here */
 		panic("Relocation error");
 	}
+
+	kaslr_early_init(__va(dt_ptr), size);
 }
 #endif
 #endif