Re: [PATCH v4 4/4] x86: mm: support ARCH_MMAP_RND_BITS.

2015-12-01 Thread Daniel Cashman
On 11/30/2015 04:03 PM, Kees Cook wrote: > On Thu, Nov 26, 2015 at 2:59 PM, Daniel Cashman wrote: >> diff --git a/arch/x86/mm/mmap.c b/arch/x86/mm/mmap.c >> index 844b06d..647fecf 100644 >> --- a/arch/x86/mm/mmap.c >> +++ b/arch/x86/mm/mmap.c >> @@ -69,14 +69,14 @@ unsigned long

Re: [PATCH v4 4/4] x86: mm: support ARCH_MMAP_RND_BITS.

2015-12-01 Thread Daniel Cashman
On 11/30/2015 04:03 PM, Kees Cook wrote: > On Thu, Nov 26, 2015 at 2:59 PM, Daniel Cashman wrote: >> diff --git a/arch/x86/mm/mmap.c b/arch/x86/mm/mmap.c >> index 844b06d..647fecf 100644 >> --- a/arch/x86/mm/mmap.c >> +++ b/arch/x86/mm/mmap.c >> @@ -69,14 +69,14 @@ unsigned

Re: [PATCH v4 4/4] x86: mm: support ARCH_MMAP_RND_BITS.

2015-11-30 Thread Kees Cook
On Thu, Nov 26, 2015 at 2:59 PM, Daniel Cashman wrote: > x86: arch_mmap_rnd() uses hard-coded values, 8 for 32-bit and 28 for > 64-bit, to generate the random offset for the mmap base address. > This value represents a compromise between increased ASLR > effectiveness and avoiding address-space

Re: [PATCH v4 4/4] x86: mm: support ARCH_MMAP_RND_BITS.

2015-11-30 Thread Kees Cook
On Thu, Nov 26, 2015 at 2:59 PM, Daniel Cashman wrote: > x86: arch_mmap_rnd() uses hard-coded values, 8 for 32-bit and 28 for > 64-bit, to generate the random offset for the mmap base address. > This value represents a compromise between increased ASLR > effectiveness and