powerpc: Randomise PIEs

Randomise ELF_ET_DYN_BASE, which is used when loading position independent
executables.

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This commit is contained in:
Anton Blanchard 2009-02-22 01:50:07 +00:00 committed by Benjamin Herrenschmidt
parent 002b0ec73d
commit 501cb16d3c
2 changed files with 12 additions and 1 deletions

View File

@ -179,7 +179,8 @@ typedef elf_fpreg_t elf_vsrreghalf_t32[ELF_NVSRHALFREG];
the loader. We need to make sure that it is out of the way of the program
that it will "exec", and that there is sufficient room for the brk. */
#define ELF_ET_DYN_BASE (0x20000000)
extern unsigned long randomize_et_dyn(unsigned long base);
#define ELF_ET_DYN_BASE (randomize_et_dyn(0x20000000))
/*
* Our registers are always unsigned longs, whether we're a 32 bit

View File

@ -1170,3 +1170,13 @@ unsigned long arch_randomize_brk(struct mm_struct *mm)
return ret;
}
unsigned long randomize_et_dyn(unsigned long base)
{
unsigned long ret = PAGE_ALIGN(base + brk_rnd());
if (ret < base)
return base;
return ret;
}