On Thu, Feb 02, 2017 at 11:12:46AM +0530, Bhupesh Sharma wrote: > This RFC patchset tries to make the powerpc ASLR elf randomness > implementation similar to other ARCHs (like x86). > > The 1st patch introduces the support of ARCH_MMAP_RND_BITS in powerpc > mmap implementation to allow a sane balance between increased randomness > in the mmap address of ASLR elfs and increased address space > fragmentation. >
>From what I see we get 28 bits of entropy right for 64k pages bits as compared to 14 bits earlier? > The 2nd patch increases the ELF_ET_DYN_BASE value from the current > hardcoded value of 0x2000_0000 to something more practical, > i.e. TASK_SIZE - PAGE_SHIFT (which makes sense especially for > 64-bit platforms which would like to utilize more randomization > in the load address of a PIE elf). > This helps PIE executables as such and leaves other not impacted? Balbir Singh