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authorDavid Daney <ddaney.cavm@gmail.com>2012-01-11 03:10:21 +0400
committerLinus Torvalds <torvalds@linux-foundation.org>2012-01-11 04:30:51 +0400
commite39f560239984c3098237ad94c9449b1494163f8 (patch)
treec86d9f84a3cb706813919ec7472fb75207bc9c8c
parent5742332dea5560d6c449b007d9539dbdc8ee531b (diff)
downloadlinux-e39f560239984c3098237ad94c9449b1494163f8.tar.xz
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 <david.daney@cavium.com> Cc: Russell King <linux@arm.linux.org.uk> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Acked-by: H. Peter Anvin <hpa@zytor.com> Cc: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--arch/arm/Kconfig1
-rw-r--r--arch/x86/Kconfig1
-rw-r--r--fs/Kconfig.binfmt3
-rw-r--r--fs/binfmt_elf.c2
4 files changed, 6 insertions, 1 deletions
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