diff mbox

[4/7] arm64: Use simpler API for random address requests

Message ID 20160728204730.27453-5-jason@lakedaemon.net
State New, archived
Headers show

Commit Message

Jason Cooper July 28, 2016, 8:47 p.m. UTC
Currently, all callers to randomize_range() set the length to 0 and
calculate end by adding a constant to the start address.  We can
simplify the API to remove a bunch of needless checks and variables.

Use the new randomize_addr(start, range) call to set the requested
address.

Signed-off-by: Jason Cooper <jason@lakedaemon.net>
---
 arch/arm64/kernel/process.c | 8 ++------
 1 file changed, 2 insertions(+), 6 deletions(-)

Comments

Will Deacon July 29, 2016, 1:48 p.m. UTC | #1
On Thu, Jul 28, 2016 at 08:47:27PM +0000, Jason Cooper wrote:
> Currently, all callers to randomize_range() set the length to 0 and
> calculate end by adding a constant to the start address.  We can
> simplify the API to remove a bunch of needless checks and variables.
> 
> Use the new randomize_addr(start, range) call to set the requested
> address.
> 
> Signed-off-by: Jason Cooper <jason@lakedaemon.net>
> ---
>  arch/arm64/kernel/process.c | 8 ++------
>  1 file changed, 2 insertions(+), 6 deletions(-)
> 
> diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c
> index 6cd2612236dc..11bf454baf86 100644
> --- a/arch/arm64/kernel/process.c
> +++ b/arch/arm64/kernel/process.c
> @@ -374,12 +374,8 @@ unsigned long arch_align_stack(unsigned long sp)
>  
>  unsigned long arch_randomize_brk(struct mm_struct *mm)
>  {
> -	unsigned long range_end = mm->brk;
> -
>  	if (is_compat_task())
> -		range_end += 0x02000000;
> +		return randomize_addr(mm->brk, 0x02000000);
>  	else
> -		range_end += 0x40000000;
> -
> -	return randomize_range(mm->brk, range_end, 0) ? : mm->brk;
> +		return randomize_addr(mm->brk, 0x40000000);

Looks fine to me, once the core code has settled down:

Acked-by: Will Deacon <will.deacon@arm.com>

Will
diff mbox

Patch

diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c
index 6cd2612236dc..11bf454baf86 100644
--- a/arch/arm64/kernel/process.c
+++ b/arch/arm64/kernel/process.c
@@ -374,12 +374,8 @@  unsigned long arch_align_stack(unsigned long sp)
 
 unsigned long arch_randomize_brk(struct mm_struct *mm)
 {
-	unsigned long range_end = mm->brk;
-
 	if (is_compat_task())
-		range_end += 0x02000000;
+		return randomize_addr(mm->brk, 0x02000000);
 	else
-		range_end += 0x40000000;
-
-	return randomize_range(mm->brk, range_end, 0) ? : mm->brk;
+		return randomize_addr(mm->brk, 0x40000000);
 }