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authorArun Chandran <achandran@mvista.com>2014-10-10 12:31:24 +0100
committerCatalin Marinas <catalin.marinas@arm.com>2014-10-24 15:47:49 +0100
commit92980405f3537136b8e81007a9df576762f49bbb (patch)
treea40d98e18e154c3d04e673842864812e14425c08
parente2b6b35ee77522c2e15e770aded0b05c25ca0616 (diff)
downloadop-kernel-dev-92980405f3537136b8e81007a9df576762f49bbb.zip
op-kernel-dev-92980405f3537136b8e81007a9df576762f49bbb.tar.gz
arm64: ASLR: Don't randomise text when randomise_va_space == 0
When user asks to turn off ASLR by writing "0" to /proc/sys/kernel/randomize_va_space there should not be any randomization to mmap base, stack, VDSO, libs, text and heap Currently arm64 violates this behavior by randomising text. Fix this by defining a constant ELF_ET_DYN_BASE. The randomisation of mm->mmap_base is done by setup_new_exec -> arch_pick_mmap_layout -> mmap_base -> mmap_rnd. Signed-off-by: Arun Chandran <achandran@mvista.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
-rw-r--r--arch/arm64/Kconfig1
-rw-r--r--arch/arm64/include/asm/elf.h4
-rw-r--r--arch/arm64/kernel/process.c5
3 files changed, 3 insertions, 7 deletions
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index b8053be..9532f8d 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -1,5 +1,6 @@
config ARM64
def_bool y
+ select ARCH_BINFMT_ELF_RANDOMIZE_PIE
select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
select ARCH_HAS_SG_CHAIN
select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
diff --git a/arch/arm64/include/asm/elf.h b/arch/arm64/include/asm/elf.h
index 01d3aab..1f65be3 100644
--- a/arch/arm64/include/asm/elf.h
+++ b/arch/arm64/include/asm/elf.h
@@ -126,7 +126,7 @@ typedef struct user_fpsimd_state elf_fpregset_t;
* 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(2 * TASK_SIZE_64 / 3))
+#define ELF_ET_DYN_BASE (2 * TASK_SIZE_64 / 3)
/*
* When the program starts, a1 contains a pointer to a function to be
@@ -169,7 +169,7 @@ extern unsigned long arch_randomize_brk(struct mm_struct *mm);
#define COMPAT_ELF_PLATFORM ("v8l")
#endif
-#define COMPAT_ELF_ET_DYN_BASE (randomize_et_dyn(2 * TASK_SIZE_32 / 3))
+#define COMPAT_ELF_ET_DYN_BASE (2 * TASK_SIZE_32 / 3)
/* AArch32 registers. */
#define COMPAT_ELF_NGREG 18
diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c
index c3065db..fde9923 100644
--- a/arch/arm64/kernel/process.c
+++ b/arch/arm64/kernel/process.c
@@ -378,8 +378,3 @@ unsigned long arch_randomize_brk(struct mm_struct *mm)
{
return randomize_base(mm->brk);
}
-
-unsigned long randomize_et_dyn(unsigned long base)
-{
- return randomize_base(base);
-}
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