From: Anton Blanchard Date: Sun, 22 Feb 2009 01:50:07 +0000 (+0000) Subject: powerpc: Randomise PIEs X-Git-Url: http://git.cdn.openwrt.org/?a=commitdiff_plain;h=501cb16d3cfd;p=openwrt%2Fstaging%2Fblogic.git powerpc: Randomise PIEs Randomise ELF_ET_DYN_BASE, which is used when loading position independent executables. Signed-off-by: Anton Blanchard Signed-off-by: Benjamin Herrenschmidt --- diff --git a/arch/powerpc/include/asm/elf.h b/arch/powerpc/include/asm/elf.h index 968b37f7a9f8..1a856b15226e 100644 --- a/arch/powerpc/include/asm/elf.h +++ b/arch/powerpc/include/asm/elf.h @@ -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 diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c index 30b149ce7598..eac064948780 100644 --- a/arch/powerpc/kernel/process.c +++ b/arch/powerpc/kernel/process.c @@ -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; +}