2020-02-06 03:00:50

by Jason Yan

[permalink] [raw]
Subject: [PATCH v3 1/6] powerpc/fsl_booke/kaslr: refactor kaslr_legal_offset() and kaslr_early_init()

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 <[email protected]>
Cc: Scott Wood <[email protected]>
Cc: Diana Craciun <[email protected]>
Cc: Michael Ellerman <[email protected]>
Cc: Christophe Leroy <[email protected]>
Cc: Benjamin Herrenschmidt <[email protected]>
Cc: Paul Mackerras <[email protected]>
Cc: Nicholas Piggin <[email protected]>
Cc: Kees Cook <[email protected]>
---
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);

/* Create kernel map to relocate in */
create_kaslr_tlb_entry(1, tlb_virt, tlb_phys);
--
2.17.2


2020-02-20 13:42:06

by Christophe Leroy

[permalink] [raw]
Subject: Re: [PATCH v3 1/6] powerpc/fsl_booke/kaslr: refactor kaslr_legal_offset() and kaslr_early_init()



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 <[email protected]>
> Cc: Scott Wood <[email protected]>
> Cc: Diana Craciun <[email protected]>
> Cc: Michael Ellerman <[email protected]>
> Cc: Christophe Leroy <[email protected]>
> Cc: Benjamin Herrenschmidt <[email protected]>
> Cc: Paul Mackerras <[email protected]>
> Cc: Nicholas Piggin <[email protected]>
> Cc: Kees Cook <[email protected]>
> ---
> 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

2020-02-26 02:12:03

by Jason Yan

[permalink] [raw]
Subject: Re: [PATCH v3 1/6] powerpc/fsl_booke/kaslr: refactor kaslr_legal_offset() and kaslr_early_init()



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 <[email protected]>
>> Cc: Scott Wood <[email protected]>
>> Cc: Diana Craciun <[email protected]>
>> Cc: Michael Ellerman <[email protected]>
>> Cc: Christophe Leroy <[email protected]>
>> Cc: Benjamin Herrenschmidt <[email protected]>
>> Cc: Paul Mackerras <[email protected]>
>> Cc: Nicholas Piggin <[email protected]>
>> Cc: Kees Cook <[email protected]>
>> ---
>>   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
>
> .