From 204db6ed17743000691d930368a5abd6ea541c58 Mon Sep 17 00:00:00 2001 From: Kees Cook Date: Tue, 14 Apr 2015 15:48:12 -0700 Subject: mm: fold arch_randomize_brk into ARCH_HAS_ELF_RANDOMIZE The arch_randomize_brk() function is used on several architectures, even those that don't support ET_DYN ASLR. To avoid bulky extern/#define tricks, consolidate the support under CONFIG_ARCH_HAS_ELF_RANDOMIZE for the architectures that support it, while still handling CONFIG_COMPAT_BRK. Signed-off-by: Kees Cook Cc: Hector Marco-Gisbert Cc: Russell King Reviewed-by: Ingo Molnar Cc: Catalin Marinas Cc: Will Deacon Cc: Ralf Baechle Cc: Benjamin Herrenschmidt Cc: Paul Mackerras Cc: Michael Ellerman Cc: Martin Schwidefsky Cc: Heiko Carstens Cc: Alexander Viro Cc: Oleg Nesterov Cc: Andy Lutomirski Cc: "David A. Long" Cc: Andrey Ryabinin Cc: Arun Chandran Cc: Yann Droneaud Cc: Min-Hua Chen Cc: Paul Burton Cc: Alex Smith Cc: Markos Chandras Cc: Vineeth Vijayan Cc: Jeff Bailey Cc: Michael Holzheu Cc: Ben Hutchings Cc: Behan Webster Cc: Ismael Ripoll Cc: Jan-Simon Mller Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds diff --git a/arch/Kconfig b/arch/Kconfig index 474904a..e106898 100644 --- a/arch/Kconfig +++ b/arch/Kconfig @@ -497,6 +497,7 @@ config ARCH_HAS_ELF_RANDOMIZE An architecture supports choosing randomized locations for stack, mmap, brk, and ET_DYN. Defined functions: - arch_mmap_rnd() + - arch_randomize_brk() # # ABI hall of shame diff --git a/arch/arm/include/asm/elf.h b/arch/arm/include/asm/elf.h index afb9caf..c1ff8ab 100644 --- a/arch/arm/include/asm/elf.h +++ b/arch/arm/include/asm/elf.h @@ -125,10 +125,6 @@ int dump_task_regs(struct task_struct *t, elf_gregset_t *elfregs); extern void elf_set_personality(const struct elf32_hdr *); #define SET_PERSONALITY(ex) elf_set_personality(&(ex)) -struct mm_struct; -extern unsigned long arch_randomize_brk(struct mm_struct *mm); -#define arch_randomize_brk arch_randomize_brk - #ifdef CONFIG_MMU #define ARCH_HAS_SETUP_ADDITIONAL_PAGES 1 struct linux_binprm; diff --git a/arch/arm64/include/asm/elf.h b/arch/arm64/include/asm/elf.h index f724db0..faad6df 100644 --- a/arch/arm64/include/asm/elf.h +++ b/arch/arm64/include/asm/elf.h @@ -156,10 +156,6 @@ extern int arch_setup_additional_pages(struct linux_binprm *bprm, #define STACK_RND_MASK (0x3ffff >> (PAGE_SHIFT - 12)) #endif -struct mm_struct; -extern unsigned long arch_randomize_brk(struct mm_struct *mm); -#define arch_randomize_brk arch_randomize_brk - #ifdef CONFIG_COMPAT #ifdef __AARCH64EB__ diff --git a/arch/mips/include/asm/elf.h b/arch/mips/include/asm/elf.h index 535f196..31d747d 100644 --- a/arch/mips/include/asm/elf.h +++ b/arch/mips/include/asm/elf.h @@ -410,10 +410,6 @@ struct linux_binprm; extern int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp); -struct mm_struct; -extern unsigned long arch_randomize_brk(struct mm_struct *mm); -#define arch_randomize_brk arch_randomize_brk - struct arch_elf_state { int fp_abi; int interp_fp_abi; diff --git a/arch/powerpc/include/asm/elf.h b/arch/powerpc/include/asm/elf.h index 57d289a..ee46ffe 100644 --- a/arch/powerpc/include/asm/elf.h +++ b/arch/powerpc/include/asm/elf.h @@ -128,10 +128,6 @@ extern int arch_setup_additional_pages(struct linux_binprm *bprm, (0x7ff >> (PAGE_SHIFT - 12)) : \ (0x3ffff >> (PAGE_SHIFT - 12))) -extern unsigned long arch_randomize_brk(struct mm_struct *mm); -#define arch_randomize_brk arch_randomize_brk - - #ifdef CONFIG_SPU_BASE /* Notes used in ET_CORE. Note name is "SPU//". */ #define NT_SPU 1 diff --git a/arch/s390/include/asm/elf.h b/arch/s390/include/asm/elf.h index ff66215..a5c4978 100644 --- a/arch/s390/include/asm/elf.h +++ b/arch/s390/include/asm/elf.h @@ -226,9 +226,6 @@ struct linux_binprm; #define ARCH_HAS_SETUP_ADDITIONAL_PAGES 1 int arch_setup_additional_pages(struct linux_binprm *, int); -extern unsigned long arch_randomize_brk(struct mm_struct *mm); -#define arch_randomize_brk arch_randomize_brk - void *fill_cpu_elf_notes(void *ptr, struct save_area *sa, __vector128 *vxrs); #endif diff --git a/arch/x86/include/asm/elf.h b/arch/x86/include/asm/elf.h index 935588d9..f161c18 100644 --- a/arch/x86/include/asm/elf.h +++ b/arch/x86/include/asm/elf.h @@ -339,9 +339,6 @@ extern int compat_arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp); #define compat_arch_setup_additional_pages compat_arch_setup_additional_pages -extern unsigned long arch_randomize_brk(struct mm_struct *mm); -#define arch_randomize_brk arch_randomize_brk - /* * True on X86_32 or when emulating IA32 on X86_64 */ diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c index b20c054..241ef68 100644 --- a/fs/binfmt_elf.c +++ b/fs/binfmt_elf.c @@ -1050,15 +1050,13 @@ static int load_elf_binary(struct linux_binprm *bprm) current->mm->end_data = end_data; current->mm->start_stack = bprm->p; -#ifdef arch_randomize_brk if ((current->flags & PF_RANDOMIZE) && (randomize_va_space > 1)) { current->mm->brk = current->mm->start_brk = arch_randomize_brk(current->mm); -#ifdef CONFIG_COMPAT_BRK +#ifdef compat_brk_randomized current->brk_randomized = 1; #endif } -#endif if (current->personality & MMAP_PAGE_ZERO) { /* Why this, you ask??? Well SVr4 maps page 0 as read-only, diff --git a/include/linux/elf-randomize.h b/include/linux/elf-randomize.h index 7a4eda0..b5f0bda 100644 --- a/include/linux/elf-randomize.h +++ b/include/linux/elf-randomize.h @@ -1,10 +1,22 @@ #ifndef _ELF_RANDOMIZE_H #define _ELF_RANDOMIZE_H +struct mm_struct; + #ifndef CONFIG_ARCH_HAS_ELF_RANDOMIZE static inline unsigned long arch_mmap_rnd(void) { return 0; } +# if defined(arch_randomize_brk) && defined(CONFIG_COMPAT_BRK) +# define compat_brk_randomized +# endif +# ifndef arch_randomize_brk +# define arch_randomize_brk(mm) (mm->brk) +# endif #else extern unsigned long arch_mmap_rnd(void); +extern unsigned long arch_randomize_brk(struct mm_struct *mm); +# ifdef CONFIG_COMPAT_BRK +# define compat_brk_randomized +# endif #endif #endif -- cgit v0.10.2