Commit d2c9dfcc authored Jan 12, 2011 by Heiko Carstens Committed by Martin Schwidefsky Jan 12, 2011

[S390] Randomize PIEs



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

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

parent 33519182

arch/s390/include/asm/elf.h

+3 −1

Original line number	Diff line number	Diff line
		@@ -161,7 +161,9 @@ extern unsigned int vdso_enabled;
		use of this is to invoke "./ld.so someprog" to test out a new version of
		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 (STACK_TOP / 3 * 2)

		extern unsigned long randomize_et_dyn(unsigned long base);
		#define ELF_ET_DYN_BASE (randomize_et_dyn(STACK_TOP / 3 * 2))

		/* This yields a mask that user programs can use to figure out what
		instruction set this CPU supports. */

arch/s390/kernel/process.c

+11 −0

Original line number	Diff line number	Diff line
		@@ -359,3 +359,14 @@ unsigned long arch_randomize_brk(struct mm_struct *mm)
		return mm->brk;
		return ret;
		}

		unsigned long randomize_et_dyn(unsigned long base)
		{
		unsigned long ret = PAGE_ALIGN(base + brk_rnd());

		if (!(current->flags & PF_RANDOMIZE))
		return base;
		if (ret < base)
		return base;
		return ret;
		}