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authorKees Cook <keescook@chromium.org>2015-04-14 15:48:00 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2015-04-14 16:49:05 -0700
commit2b68f6caeac271620cd2f9362aeaed360e317df0 (patch)
tree8dae384ab3db6e078675a9bb63e4f58b0ab50dd4
parent8e89a356feb6f196824a72101861d931a97ac2d2 (diff)
downloadlinux-2b68f6caeac271620cd2f9362aeaed360e317df0.tar.bz2
mm: expose arch_mmap_rnd when available
When an architecture fully supports randomizing the ELF load location, a per-arch mmap_rnd() function is used to find a randomized mmap base. In preparation for randomizing the location of ET_DYN binaries separately from mmap, this renames and exports these functions as arch_mmap_rnd(). Additionally introduces CONFIG_ARCH_HAS_ELF_RANDOMIZE for describing this feature on architectures that support it (which is a superset of ARCH_BINFMT_ELF_RANDOMIZE_PIE, since s390 already supports a separated ET_DYN ASLR from mmap ASLR without the ARCH_BINFMT_ELF_RANDOMIZE_PIE logic). Signed-off-by: Kees Cook <keescook@chromium.org> Cc: Hector Marco-Gisbert <hecmargi@upv.es> Cc: Russell King <linux@arm.linux.org.uk> Reviewed-by: Ingo Molnar <mingo@kernel.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: "David A. Long" <dave.long@linaro.org> Cc: Andrey Ryabinin <a.ryabinin@samsung.com> Cc: Arun Chandran <achandran@mvista.com> Cc: Yann Droneaud <ydroneaud@opteya.com> Cc: Min-Hua Chen <orca.chen@gmail.com> Cc: Paul Burton <paul.burton@imgtec.com> Cc: Alex Smith <alex@alex-smith.me.uk> Cc: Markos Chandras <markos.chandras@imgtec.com> Cc: Vineeth Vijayan <vvijayan@mvista.com> Cc: Jeff Bailey <jeffbailey@google.com> Cc: Michael Holzheu <holzheu@linux.vnet.ibm.com> Cc: Ben Hutchings <ben@decadent.org.uk> Cc: Behan Webster <behanw@converseincode.com> Cc: Ismael Ripoll <iripoll@upv.es> Cc: Jan-Simon Mller <dl9pf@gmx.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--arch/Kconfig7
-rw-r--r--arch/arm/Kconfig1
-rw-r--r--arch/arm/mm/mmap.c4
-rw-r--r--arch/arm64/Kconfig1
-rw-r--r--arch/arm64/mm/mmap.c4
-rw-r--r--arch/mips/Kconfig1
-rw-r--r--arch/mips/mm/mmap.c4
-rw-r--r--arch/powerpc/Kconfig1
-rw-r--r--arch/powerpc/mm/mmap.c4
-rw-r--r--arch/s390/Kconfig1
-rw-r--r--arch/s390/mm/mmap.c8
-rw-r--r--arch/x86/Kconfig1
-rw-r--r--arch/x86/mm/mmap.c4
-rw-r--r--include/linux/elf-randomize.h10
14 files changed, 37 insertions, 14 deletions
diff --git a/arch/Kconfig b/arch/Kconfig
index c88c23f0a1da..474904a8e540 100644
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -491,6 +491,13 @@ config PGTABLE_LEVELS
int
default 2
+config ARCH_HAS_ELF_RANDOMIZE
+ bool
+ help
+ An architecture supports choosing randomized locations for
+ stack, mmap, brk, and ET_DYN. Defined functions:
+ - arch_mmap_rnd()
+
#
# ABI hall of shame
#
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 696cf3c61e0f..f85200a63a8b 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -3,6 +3,7 @@ config ARM
default y
select ARCH_BINFMT_ELF_RANDOMIZE_PIE
select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
+ select ARCH_HAS_ELF_RANDOMIZE
select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
select ARCH_HAVE_CUSTOM_GPIO_H
select ARCH_HAS_GCOV_PROFILE_ALL
diff --git a/arch/arm/mm/mmap.c b/arch/arm/mm/mmap.c
index 15a8160096b3..407dc786583a 100644
--- a/arch/arm/mm/mmap.c
+++ b/arch/arm/mm/mmap.c
@@ -169,7 +169,7 @@ arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0,
return addr;
}
-static unsigned long mmap_rnd(void)
+unsigned long arch_mmap_rnd(void)
{
unsigned long rnd;
@@ -184,7 +184,7 @@ void arch_pick_mmap_layout(struct mm_struct *mm)
unsigned long random_factor = 0UL;
if (current->flags & PF_RANDOMIZE)
- random_factor = mmap_rnd();
+ random_factor = arch_mmap_rnd();
if (mmap_is_legacy()) {
mm->mmap_base = TASK_UNMAPPED_BASE + random_factor;
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 3f2fba996bc2..7c1dbeb73e8d 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -2,6 +2,7 @@ config ARM64
def_bool y
select ARCH_BINFMT_ELF_RANDOMIZE_PIE
select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
+ select ARCH_HAS_ELF_RANDOMIZE
select ARCH_HAS_GCOV_PROFILE_ALL
select ARCH_HAS_SG_CHAIN
select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
diff --git a/arch/arm64/mm/mmap.c b/arch/arm64/mm/mmap.c
index ba776c01b552..ed177475dd8c 100644
--- a/arch/arm64/mm/mmap.c
+++ b/arch/arm64/mm/mmap.c
@@ -47,7 +47,7 @@ static int mmap_is_legacy(void)
return sysctl_legacy_va_layout;
}
-static unsigned long mmap_rnd(void)
+unsigned long arch_mmap_rnd(void)
{
unsigned long rnd;
@@ -77,7 +77,7 @@ void arch_pick_mmap_layout(struct mm_struct *mm)
unsigned long random_factor = 0UL;
if (current->flags & PF_RANDOMIZE)
- random_factor = mmap_rnd();
+ random_factor = arch_mmap_rnd();
/*
* Fall back to the standard layout if the personality bit is set, or
diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index a9d112d2a135..688ce274f59d 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -24,6 +24,7 @@ config MIPS
select HAVE_DEBUG_KMEMLEAK
select HAVE_SYSCALL_TRACEPOINTS
select ARCH_BINFMT_ELF_RANDOMIZE_PIE
+ select ARCH_HAS_ELF_RANDOMIZE
select HAVE_ARCH_TRANSPARENT_HUGEPAGE if CPU_SUPPORTS_HUGEPAGES && 64BIT
select RTC_LIB if !MACH_LOONGSON
select GENERIC_ATOMIC64 if !64BIT
diff --git a/arch/mips/mm/mmap.c b/arch/mips/mm/mmap.c
index 9a4f1f5c1f0e..5c81fdd032c3 100644
--- a/arch/mips/mm/mmap.c
+++ b/arch/mips/mm/mmap.c
@@ -142,7 +142,7 @@ unsigned long arch_get_unmapped_area_topdown(struct file *filp,
addr0, len, pgoff, flags, DOWN);
}
-static unsigned long mmap_rnd(void)
+unsigned long arch_mmap_rnd(void)
{
unsigned long rnd;
@@ -161,7 +161,7 @@ void arch_pick_mmap_layout(struct mm_struct *mm)
unsigned long random_factor = 0UL;
if (current->flags & PF_RANDOMIZE)
- random_factor = mmap_rnd();
+ random_factor = arch_mmap_rnd();
if (mmap_is_legacy()) {
mm->mmap_base = TASK_UNMAPPED_BASE + random_factor;
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 91ad76f30d18..fc5fffbb331b 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -89,6 +89,7 @@ config PPC
select ARCH_MIGHT_HAVE_PC_SERIO
select BINFMT_ELF
select ARCH_BINFMT_ELF_RANDOMIZE_PIE
+ select ARCH_HAS_ELF_RANDOMIZE
select OF
select OF_EARLY_FLATTREE
select OF_RESERVED_MEM
diff --git a/arch/powerpc/mm/mmap.c b/arch/powerpc/mm/mmap.c
index 1ad2299d795d..0f0502e12f6c 100644
--- a/arch/powerpc/mm/mmap.c
+++ b/arch/powerpc/mm/mmap.c
@@ -53,7 +53,7 @@ static inline int mmap_is_legacy(void)
return sysctl_legacy_va_layout;
}
-static unsigned long mmap_rnd(void)
+unsigned long arch_mmap_rnd(void)
{
unsigned long rnd;
@@ -87,7 +87,7 @@ void arch_pick_mmap_layout(struct mm_struct *mm)
unsigned long random_factor = 0UL;
if (current->flags & PF_RANDOMIZE)
- random_factor = mmap_rnd();
+ random_factor = arch_mmap_rnd();
/*
* Fall back to the standard layout if the personality
diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index f6aebcb7a0f8..ac2b75d74cd2 100644
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -65,6 +65,7 @@ config S390
def_bool y
select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
select ARCH_HAS_DEBUG_STRICT_USER_COPY_CHECKS
+ select ARCH_HAS_ELF_RANDOMIZE
select ARCH_HAS_GCOV_PROFILE_ALL
select ARCH_HAS_SG_CHAIN
select ARCH_HAVE_NMI_SAFE_CMPXCHG
diff --git a/arch/s390/mm/mmap.c b/arch/s390/mm/mmap.c
index db57078075c5..a94504d99c47 100644
--- a/arch/s390/mm/mmap.c
+++ b/arch/s390/mm/mmap.c
@@ -60,7 +60,7 @@ static inline int mmap_is_legacy(void)
return sysctl_legacy_va_layout;
}
-static unsigned long mmap_rnd(void)
+unsigned long arch_mmap_rnd(void)
{
if (is_32bit_task())
return (get_random_int() & 0x7ff) << PAGE_SHIFT;
@@ -187,7 +187,7 @@ unsigned long randomize_et_dyn(void)
base &= ~((1UL << 32) - 1);
if (current->flags & PF_RANDOMIZE)
- base += mmap_rnd();
+ base += arch_mmap_rnd();
return base;
}
@@ -203,7 +203,7 @@ void arch_pick_mmap_layout(struct mm_struct *mm)
unsigned long random_factor = 0UL;
if (current->flags & PF_RANDOMIZE)
- random_factor = mmap_rnd();
+ random_factor = arch_mmap_rnd();
/*
* Fall back to the standard layout if the personality
@@ -283,7 +283,7 @@ void arch_pick_mmap_layout(struct mm_struct *mm)
unsigned long random_factor = 0UL;
if (current->flags & PF_RANDOMIZE)
- random_factor = mmap_rnd();
+ random_factor = arch_mmap_rnd();
/*
* Fall back to the standard layout if the personality
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 0f948cefaeb1..782ddbbc1c9a 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -88,6 +88,7 @@ config X86
select HAVE_ARCH_KASAN if X86_64 && SPARSEMEM_VMEMMAP
select HAVE_USER_RETURN_NOTIFIER
select ARCH_BINFMT_ELF_RANDOMIZE_PIE
+ select ARCH_HAS_ELF_RANDOMIZE
select HAVE_ARCH_JUMP_LABEL
select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
select SPARSE_IRQ
diff --git a/arch/x86/mm/mmap.c b/arch/x86/mm/mmap.c
index ebfa52030d5c..9d518d693b4b 100644
--- a/arch/x86/mm/mmap.c
+++ b/arch/x86/mm/mmap.c
@@ -65,7 +65,7 @@ static int mmap_is_legacy(void)
return sysctl_legacy_va_layout;
}
-static unsigned long mmap_rnd(void)
+unsigned long arch_mmap_rnd(void)
{
unsigned long rnd;
@@ -114,7 +114,7 @@ void arch_pick_mmap_layout(struct mm_struct *mm)
unsigned long random_factor = 0UL;
if (current->flags & PF_RANDOMIZE)
- random_factor = mmap_rnd();
+ random_factor = arch_mmap_rnd();
mm->mmap_legacy_base = mmap_legacy_base(random_factor);
diff --git a/include/linux/elf-randomize.h b/include/linux/elf-randomize.h
new file mode 100644
index 000000000000..7a4eda02d2b1
--- /dev/null
+++ b/include/linux/elf-randomize.h
@@ -0,0 +1,10 @@
+#ifndef _ELF_RANDOMIZE_H
+#define _ELF_RANDOMIZE_H
+
+#ifndef CONFIG_ARCH_HAS_ELF_RANDOMIZE
+static inline unsigned long arch_mmap_rnd(void) { return 0; }
+#else
+extern unsigned long arch_mmap_rnd(void);
+#endif
+
+#endif