Eric Lee / smarc-ti-linux-kernel

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Commit 92980405f3537136b8e81007a9df576762f49bbb

Authored by Arun Chandran
Committed by Catalin Marinas
1 parent e2b6b35ee7
Exists in ti-lsk-linux-4.1.y and in 10 other branches dlt-processor-sdk-linux-03.00.00.04, processor-sdk-linux-02.00.01, smarc-ti-lsk-linux-4.1.y, smarct3x-processor-sdk-04.01.00.06, smarct3x-processor-sdk-linux-02.00.01, smarct3x-processor-sdk-linux-03.00.00.04, smarct4x-800-processor-sdk-linux-02.00.01, smarct4x-processor-sdk-04.01.00.06, smarct4x-processor-sdk-linux-02.00.01, smarct4x-processor-sdk-linux-03.00.00.04

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>

Showing 3 changed files with 3 additions and 7 deletions Side-by-side Diff

1 1 config ARM64
2 2 def_bool y
  3 + select ARCH_BINFMT_ELF_RANDOMIZE_PIE
3 4 select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
4 5 select ARCH_HAS_SG_CHAIN
5 6 select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
arch/arm64/include/asm/elf.h
Diff comments   View file @ 9298040
... ... @@ -126,7 +126,7 @@
126 126 * that it will "exec", and that there is sufficient room for the brk.
127 127 */
128 128 extern unsigned long randomize_et_dyn(unsigned long base);
129   -#define ELF_ET_DYN_BASE (randomize_et_dyn(2 * TASK_SIZE_64 / 3))
  129 +#define ELF_ET_DYN_BASE (2 * TASK_SIZE_64 / 3)
130 130  
131 131 /*
132 132 * When the program starts, a1 contains a pointer to a function to be
... ... @@ -169,7 +169,7 @@
169 169 #define COMPAT_ELF_PLATFORM ("v8l")
170 170 #endif
171 171  
172   -#define COMPAT_ELF_ET_DYN_BASE (randomize_et_dyn(2 * TASK_SIZE_32 / 3))
  172 +#define COMPAT_ELF_ET_DYN_BASE (2 * TASK_SIZE_32 / 3)
173 173  
174 174 /* AArch32 registers. */
175 175 #define COMPAT_ELF_NGREG 18
arch/arm64/kernel/process.c
Diff comments   View file @ 9298040
... ... @@ -378,9 +378,4 @@
378 378 {
379 379 return randomize_base(mm->brk);
380 380 }
381   -
382   -unsigned long randomize_et_dyn(unsigned long base)
383   -{
384   - return randomize_base(base);
385   -}