From e39f560239984c3098237ad94c9449b1494163f8 Mon Sep 17 00:00:00 2001 From: David Daney Date: Tue, 10 Jan 2012 15:10:21 -0800 Subject: [PATCH] fs: binfmt_elf: create Kconfig variable for PIE randomization Randomization of PIE load address is hard coded in binfmt_elf.c for X86 and ARM. Create a new Kconfig variable (CONFIG_ARCH_BINFMT_ELF_RANDOMIZE_PIE) for this and use it instead. Thus architecture specific policy is pushed out of the generic binfmt_elf.c and into the architecture Kconfig files. X86 and ARM Kconfigs are modified to select the new variable so there is no change in behavior. A follow on patch will select it for MIPS too. Signed-off-by: David Daney Cc: Russell King Cc: Thomas Gleixner Cc: Ingo Molnar Cc: "H. Peter Anvin" Cc: Alexander Viro Acked-by: H. Peter Anvin Cc: Ralf Baechle Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/arm/Kconfig | 1 + arch/x86/Kconfig | 1 + fs/Kconfig.binfmt | 3 +++ fs/binfmt_elf.c | 2 +- 4 files changed, 6 insertions(+), 1 deletion(-) diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index 9d66dfc33a5a..98a6459cd398 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -16,6 +16,7 @@ config ARM select HAVE_FTRACE_MCOUNT_RECORD if (!XIP_KERNEL) select HAVE_DYNAMIC_FTRACE if (!XIP_KERNEL) select HAVE_FUNCTION_GRAPH_TRACER if (!THUMB2_KERNEL) + select ARCH_BINFMT_ELF_RANDOMIZE_PIE select HAVE_GENERIC_DMA_COHERENT select HAVE_KERNEL_GZIP select HAVE_KERNEL_LZO diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 1d2a69dd36d8..d6ddc0bfe36a 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -62,6 +62,7 @@ config X86 select ANON_INODES select HAVE_ARCH_KMEMCHECK select HAVE_USER_RETURN_NOTIFIER + select ARCH_BINFMT_ELF_RANDOMIZE_PIE select HAVE_ARCH_JUMP_LABEL select HAVE_TEXT_POKE_SMP select HAVE_GENERIC_HARDIRQS diff --git a/fs/Kconfig.binfmt b/fs/Kconfig.binfmt index 79e2ca7973b7..e95d1b64082c 100644 --- a/fs/Kconfig.binfmt +++ b/fs/Kconfig.binfmt @@ -27,6 +27,9 @@ config COMPAT_BINFMT_ELF bool depends on COMPAT && BINFMT_ELF +config ARCH_BINFMT_ELF_RANDOMIZE_PIE + bool + config BINFMT_ELF_FDPIC bool "Kernel support for FDPIC ELF binaries" default y diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c index 21ac5ee4b43f..bcb884e2d613 100644 --- a/fs/binfmt_elf.c +++ b/fs/binfmt_elf.c @@ -794,7 +794,7 @@ static int load_elf_binary(struct linux_binprm *bprm, struct pt_regs *regs) * default mmap base, as well as whatever program they * might try to exec. This is because the brk will * follow the loader, and is not movable. */ -#if defined(CONFIG_X86) || defined(CONFIG_ARM) +#ifdef CONFIG_ARCH_BINFMT_ELF_RANDOMIZE_PIE /* Memory randomization might have been switched off * in runtime via sysctl. * If that is the case, retain the original non-zero -- 2.20.1