Commit 2b68f6ca authored by Kees Cook's avatar Kees Cook Committed by Linus Torvalds
Browse files

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: default avatarKees Cook <keescook@chromium.org>
Cc: Hector Marco-Gisbert <hecmargi@upv.es>
Cc: Russell King <linux@arm.linux.org.uk>
Reviewed-by: default avatarIngo 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: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 8e89a356
......@@ -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
#
......
......@@ -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
......
......@@ -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;
......
......@@ -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
......
......@@ -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
......
......@@ -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
......
......@@ -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;
......
......@@ -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
......
......@@ -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
......
......@@ -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
......
......@@ -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
......
......@@ -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
......
......@@ -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);
......
#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
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