[v3,1/6] powerpc/fsl_booke/kaslr: refactor kaslr_legal_offset() and kaslr_early_init()
diff mbox series

Message ID 20200206025825.22934-2-yanaijie@huawei.com
State New
Headers show
Series
  • implement KASLR for powerpc/fsl_booke/64
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Commit Message

Jason Yan Feb. 6, 2020, 2:58 a.m. UTC
Some code refactor in kaslr_legal_offset() and kaslr_early_init(). No
functional change. This is a preparation for KASLR fsl_booke64.

Signed-off-by: Jason Yan <yanaijie@huawei.com>
Cc: Scott Wood <oss@buserror.net>
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/mm/nohash/kaslr_booke.c | 40 ++++++++++++++--------------
 1 file changed, 20 insertions(+), 20 deletions(-)

Comments

Christophe Leroy Feb. 20, 2020, 1:40 p.m. UTC | #1
Le 06/02/2020 à 03:58, Jason Yan a écrit :
> Some code refactor in kaslr_legal_offset() and kaslr_early_init(). No
> functional change. This is a preparation for KASLR fsl_booke64.
> 
> Signed-off-by: Jason Yan <yanaijie@huawei.com>
> Cc: Scott Wood <oss@buserror.net>
> 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/mm/nohash/kaslr_booke.c | 40 ++++++++++++++--------------
>   1 file changed, 20 insertions(+), 20 deletions(-)
> 
> diff --git a/arch/powerpc/mm/nohash/kaslr_booke.c b/arch/powerpc/mm/nohash/kaslr_booke.c
> index 4a75f2d9bf0e..07b036e98353 100644
> --- a/arch/powerpc/mm/nohash/kaslr_booke.c
> +++ b/arch/powerpc/mm/nohash/kaslr_booke.c
> @@ -25,6 +25,7 @@ struct regions {
>   	unsigned long pa_start;
>   	unsigned long pa_end;
>   	unsigned long kernel_size;
> +	unsigned long linear_sz;
>   	unsigned long dtb_start;
>   	unsigned long dtb_end;
>   	unsigned long initrd_start;
> @@ -260,11 +261,23 @@ static __init void get_cell_sizes(const void *fdt, int node, int *addr_cells,
>   		*size_cells = fdt32_to_cpu(*prop);
>   }
>   
> -static unsigned long __init kaslr_legal_offset(void *dt_ptr, unsigned long index,
> -					       unsigned long offset)
> +static unsigned long __init kaslr_legal_offset(void *dt_ptr, unsigned long random)
>   {
>   	unsigned long koffset = 0;
>   	unsigned long start;
> +	unsigned long index;
> +	unsigned long offset;
> +
> +	/*
> +	 * Decide which 64M we want to start
> +	 * Only use the low 8 bits of the random seed
> +	 */
> +	index = random & 0xFF;
> +	index %= regions.linear_sz / SZ_64M;
> +
> +	/* Decide offset inside 64M */
> +	offset = random % (SZ_64M - regions.kernel_size);
> +	offset = round_down(offset, SZ_16K);
>   
>   	while ((long)index >= 0) {
>   		offset = memstart_addr + index * SZ_64M + offset;
> @@ -289,10 +302,9 @@ static inline __init bool kaslr_disabled(void)
>   static unsigned long __init kaslr_choose_location(void *dt_ptr, phys_addr_t size,
>   						  unsigned long kernel_sz)
>   {
> -	unsigned long offset, random;
> +	unsigned long random;
>   	unsigned long ram, linear_sz;
>   	u64 seed;
> -	unsigned long index;
>   
>   	kaslr_get_cmdline(dt_ptr);
>   	if (kaslr_disabled())
> @@ -333,22 +345,12 @@ static unsigned long __init kaslr_choose_location(void *dt_ptr, phys_addr_t size
>   	regions.dtb_start = __pa(dt_ptr);
>   	regions.dtb_end = __pa(dt_ptr) + fdt_totalsize(dt_ptr);
>   	regions.kernel_size = kernel_sz;
> +	regions.linear_sz = linear_sz;
>   
>   	get_initrd_range(dt_ptr);
>   	get_crash_kernel(dt_ptr, ram);
>   
> -	/*
> -	 * Decide which 64M we want to start
> -	 * Only use the low 8 bits of the random seed
> -	 */
> -	index = random & 0xFF;
> -	index %= linear_sz / SZ_64M;
> -
> -	/* Decide offset inside 64M */
> -	offset = random % (SZ_64M - kernel_sz);
> -	offset = round_down(offset, SZ_16K);
> -
> -	return kaslr_legal_offset(dt_ptr, index, offset);
> +	return kaslr_legal_offset(dt_ptr, random);
>   }
>   
>   /*
> @@ -358,8 +360,6 @@ static unsigned long __init kaslr_choose_location(void *dt_ptr, phys_addr_t size
>    */
>   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;
>   
> @@ -375,8 +375,8 @@ notrace void __init kaslr_early_init(void *dt_ptr, phys_addr_t size)
>   	is_second_reloc = 1;
>   
>   	if (offset >= SZ_64M) {
> -		tlb_virt = round_down(kernstart_virt_addr, SZ_64M);
> -		tlb_phys = round_down(kernstart_addr, SZ_64M);
> +		unsigned long tlb_virt = round_down(kernstart_virt_addr, SZ_64M);
> +		phys_addr_t tlb_phys = round_down(kernstart_addr, SZ_64M);

That looks like cleanup unrelated to the patch itself.

>   
>   		/* Create kernel map to relocate in */
>   		create_kaslr_tlb_entry(1, tlb_virt, tlb_phys);
> 

Christophe
Jason Yan Feb. 26, 2020, 2:11 a.m. UTC | #2
在 2020/2/20 21:40, Christophe Leroy 写道:
> 
> 
> Le 06/02/2020 à 03:58, Jason Yan a écrit :
>> Some code refactor in kaslr_legal_offset() and kaslr_early_init(). No
>> functional change. This is a preparation for KASLR fsl_booke64.
>>
>> Signed-off-by: Jason Yan <yanaijie@huawei.com>
>> Cc: Scott Wood <oss@buserror.net>
>> 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/mm/nohash/kaslr_booke.c | 40 ++++++++++++++--------------
>>   1 file changed, 20 insertions(+), 20 deletions(-)
>>
>> diff --git a/arch/powerpc/mm/nohash/kaslr_booke.c 
>> b/arch/powerpc/mm/nohash/kaslr_booke.c
>> index 4a75f2d9bf0e..07b036e98353 100644
>> --- a/arch/powerpc/mm/nohash/kaslr_booke.c
>> +++ b/arch/powerpc/mm/nohash/kaslr_booke.c
>> @@ -25,6 +25,7 @@ struct regions {
>>       unsigned long pa_start;
>>       unsigned long pa_end;
>>       unsigned long kernel_size;
>> +    unsigned long linear_sz;
>>       unsigned long dtb_start;
>>       unsigned long dtb_end;
>>       unsigned long initrd_start;
>> @@ -260,11 +261,23 @@ static __init void get_cell_sizes(const void 
>> *fdt, int node, int *addr_cells,
>>           *size_cells = fdt32_to_cpu(*prop);
>>   }
>> -static unsigned long __init kaslr_legal_offset(void *dt_ptr, unsigned 
>> long index,
>> -                           unsigned long offset)
>> +static unsigned long __init kaslr_legal_offset(void *dt_ptr, unsigned 
>> long random)
>>   {
>>       unsigned long koffset = 0;
>>       unsigned long start;
>> +    unsigned long index;
>> +    unsigned long offset;
>> +
>> +    /*
>> +     * Decide which 64M we want to start
>> +     * Only use the low 8 bits of the random seed
>> +     */
>> +    index = random & 0xFF;
>> +    index %= regions.linear_sz / SZ_64M;
>> +
>> +    /* Decide offset inside 64M */
>> +    offset = random % (SZ_64M - regions.kernel_size);
>> +    offset = round_down(offset, SZ_16K);
>>       while ((long)index >= 0) {
>>           offset = memstart_addr + index * SZ_64M + offset;
>> @@ -289,10 +302,9 @@ static inline __init bool kaslr_disabled(void)
>>   static unsigned long __init kaslr_choose_location(void *dt_ptr, 
>> phys_addr_t size,
>>                             unsigned long kernel_sz)
>>   {
>> -    unsigned long offset, random;
>> +    unsigned long random;
>>       unsigned long ram, linear_sz;
>>       u64 seed;
>> -    unsigned long index;
>>       kaslr_get_cmdline(dt_ptr);
>>       if (kaslr_disabled())
>> @@ -333,22 +345,12 @@ static unsigned long __init 
>> kaslr_choose_location(void *dt_ptr, phys_addr_t size
>>       regions.dtb_start = __pa(dt_ptr);
>>       regions.dtb_end = __pa(dt_ptr) + fdt_totalsize(dt_ptr);
>>       regions.kernel_size = kernel_sz;
>> +    regions.linear_sz = linear_sz;
>>       get_initrd_range(dt_ptr);
>>       get_crash_kernel(dt_ptr, ram);
>> -    /*
>> -     * Decide which 64M we want to start
>> -     * Only use the low 8 bits of the random seed
>> -     */
>> -    index = random & 0xFF;
>> -    index %= linear_sz / SZ_64M;
>> -
>> -    /* Decide offset inside 64M */
>> -    offset = random % (SZ_64M - kernel_sz);
>> -    offset = round_down(offset, SZ_16K);
>> -
>> -    return kaslr_legal_offset(dt_ptr, index, offset);
>> +    return kaslr_legal_offset(dt_ptr, random);
>>   }
>>   /*
>> @@ -358,8 +360,6 @@ static unsigned long __init 
>> kaslr_choose_location(void *dt_ptr, phys_addr_t size
>>    */
>>   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;
>> @@ -375,8 +375,8 @@ notrace void __init kaslr_early_init(void *dt_ptr, 
>> phys_addr_t size)
>>       is_second_reloc = 1;
>>       if (offset >= SZ_64M) {
>> -        tlb_virt = round_down(kernstart_virt_addr, SZ_64M);
>> -        tlb_phys = round_down(kernstart_addr, SZ_64M);
>> +        unsigned long tlb_virt = round_down(kernstart_virt_addr, 
>> SZ_64M);
>> +        phys_addr_t tlb_phys = round_down(kernstart_addr, SZ_64M);
> 
> That looks like cleanup unrelated to the patch itself.

Hi, Christophe

These two variables is only for the booke32 code, so I moved the
definition here so that I can save a "#ifdef CONFIG_PPC32" for them.

Thanks,
Jason

> 
>>           /* Create kernel map to relocate in */
>>           create_kaslr_tlb_entry(1, tlb_virt, tlb_phys);
>>
> 
> Christophe
> 
> .

Patch
diff mbox series

diff --git a/arch/powerpc/mm/nohash/kaslr_booke.c b/arch/powerpc/mm/nohash/kaslr_booke.c
index 4a75f2d9bf0e..07b036e98353 100644
--- a/arch/powerpc/mm/nohash/kaslr_booke.c
+++ b/arch/powerpc/mm/nohash/kaslr_booke.c
@@ -25,6 +25,7 @@  struct regions {
 	unsigned long pa_start;
 	unsigned long pa_end;
 	unsigned long kernel_size;
+	unsigned long linear_sz;
 	unsigned long dtb_start;
 	unsigned long dtb_end;
 	unsigned long initrd_start;
@@ -260,11 +261,23 @@  static __init void get_cell_sizes(const void *fdt, int node, int *addr_cells,
 		*size_cells = fdt32_to_cpu(*prop);
 }
 
-static unsigned long __init kaslr_legal_offset(void *dt_ptr, unsigned long index,
-					       unsigned long offset)
+static unsigned long __init kaslr_legal_offset(void *dt_ptr, unsigned long random)
 {
 	unsigned long koffset = 0;
 	unsigned long start;
+	unsigned long index;
+	unsigned long offset;
+
+	/*
+	 * Decide which 64M we want to start
+	 * Only use the low 8 bits of the random seed
+	 */
+	index = random & 0xFF;
+	index %= regions.linear_sz / SZ_64M;
+
+	/* Decide offset inside 64M */
+	offset = random % (SZ_64M - regions.kernel_size);
+	offset = round_down(offset, SZ_16K);
 
 	while ((long)index >= 0) {
 		offset = memstart_addr + index * SZ_64M + offset;
@@ -289,10 +302,9 @@  static inline __init bool kaslr_disabled(void)
 static unsigned long __init kaslr_choose_location(void *dt_ptr, phys_addr_t size,
 						  unsigned long kernel_sz)
 {
-	unsigned long offset, random;
+	unsigned long random;
 	unsigned long ram, linear_sz;
 	u64 seed;
-	unsigned long index;
 
 	kaslr_get_cmdline(dt_ptr);
 	if (kaslr_disabled())
@@ -333,22 +345,12 @@  static unsigned long __init kaslr_choose_location(void *dt_ptr, phys_addr_t size
 	regions.dtb_start = __pa(dt_ptr);
 	regions.dtb_end = __pa(dt_ptr) + fdt_totalsize(dt_ptr);
 	regions.kernel_size = kernel_sz;
+	regions.linear_sz = linear_sz;
 
 	get_initrd_range(dt_ptr);
 	get_crash_kernel(dt_ptr, ram);
 
-	/*
-	 * Decide which 64M we want to start
-	 * Only use the low 8 bits of the random seed
-	 */
-	index = random & 0xFF;
-	index %= linear_sz / SZ_64M;
-
-	/* Decide offset inside 64M */
-	offset = random % (SZ_64M - kernel_sz);
-	offset = round_down(offset, SZ_16K);
-
-	return kaslr_legal_offset(dt_ptr, index, offset);
+	return kaslr_legal_offset(dt_ptr, random);
 }
 
 /*
@@ -358,8 +360,6 @@  static unsigned long __init kaslr_choose_location(void *dt_ptr, phys_addr_t size
  */
 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;
 
@@ -375,8 +375,8 @@  notrace void __init kaslr_early_init(void *dt_ptr, phys_addr_t size)
 	is_second_reloc = 1;
 
 	if (offset >= SZ_64M) {
-		tlb_virt = round_down(kernstart_virt_addr, SZ_64M);
-		tlb_phys = round_down(kernstart_addr, SZ_64M);
+		unsigned long tlb_virt = round_down(kernstart_virt_addr, SZ_64M);
+		phys_addr_t tlb_phys = round_down(kernstart_addr, SZ_64M);
 
 		/* Create kernel map to relocate in */
 		create_kaslr_tlb_entry(1, tlb_virt, tlb_phys);