[PATCH] [powerpc] Fix Text randomization

From: Vineeth Vijayan
Date: Fri Nov 14 2014 - 04:12:33 EST


Now there is no way to disable TEXT randomization on a PPC32/PPC64
machine. Text randomization happens even in the case of "echo 0 >
/proc/sys/kernel/randomize_va_space"

This happens due to the incorrect definition of ELF_ET_DYN_BASE
at arch/powerpc/include/asm/elf.h

The function randomize_et_dyn is redundant and is removed.

Signed-off-by: Vineeth Vijayan <vvijayan@xxxxxxxxxx>
---
arch/powerpc/Kconfig | 1 +
arch/powerpc/include/asm/elf.h | 3 +--
arch/powerpc/kernel/process.c | 9 ---------
3 files changed, 2 insertions(+), 11 deletions(-)

diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 88eace4..868a3c4 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -88,6 +88,7 @@ config PPC
select ARCH_MIGHT_HAVE_PC_PARPORT
select ARCH_MIGHT_HAVE_PC_SERIO
select BINFMT_ELF
+ select ARCH_BINFMT_ELF_RANDOMIZE_PIE
select OF
select OF_EARLY_FLATTREE
select OF_RESERVED_MEM
diff --git a/arch/powerpc/include/asm/elf.h b/arch/powerpc/include/asm/elf.h
index 888d8f3..3793675 100644
--- a/arch/powerpc/include/asm/elf.h
+++ b/arch/powerpc/include/asm/elf.h
@@ -28,8 +28,7 @@
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. */

-extern unsigned long randomize_et_dyn(unsigned long base);
-#define ELF_ET_DYN_BASE (randomize_et_dyn(0x20000000))
+#define ELF_ET_DYN_BASE (0x20000000)

#define ELF_CORE_EFLAGS (is_elf2_task() ? 2 : 0)

diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index 923cd2d..e50467e 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -1665,12 +1665,3 @@ 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;
-}
--
1.7.9.5

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