From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932078AbbCCAZi (ORCPT ); Mon, 2 Mar 2015 19:25:38 -0500 Received: from smtp.outflux.net ([198.145.64.163]:57487 "EHLO smtp.outflux.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754134AbbCCAZe (ORCPT ); Mon, 2 Mar 2015 19:25:34 -0500 From: Kees Cook To: akpm@linux-foundation.org Cc: Kees Cook , linux-kernel@vger.kernel.org, Russell King , Catalin Marinas , Will Deacon , Ralf Baechle , Benjamin Herrenschmidt , Paul Mackerras , Michael Ellerman , Martin Schwidefsky , Heiko Carstens , linux390@de.ibm.com, x86@kernel.org, Alexander Viro , Oleg Nesterov , Andy Lutomirski , "David A. Long" , Andrey Ryabinin , Arun Chandran , Yann Droneaud , Min-Hua Chen , Paul Burton , Alex Smith , Markos Chandras , Jeff Bailey , Vineeth Vijayan , Michael Holzheu , Ben Hutchings , Hector Marco-Gisbert , Borislav Petkov , =?UTF-8?q?Jan-Simon=20M=C3=B6ller?= , linux-arm-kernel@lists.infradead.org, linux-mips@linux-mips.org, linuxppc-dev@lists.ozlabs.org, linux-s390@vger.kernel.org, linux-fsdevel@vger.kernel.org Subject: [PATCH 2/5] mm: expose arch_mmap_rnd when available Date: Mon, 2 Mar 2015 16:19:45 -0800 Message-Id: <1425341988-1599-3-git-send-email-keescook@chromium.org> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1425341988-1599-1-git-send-email-keescook@chromium.org> References: <1425341988-1599-1-git-send-email-keescook@chromium.org> X-HELO: www.outflux.net Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org When an architecture fully supports randomizing the ELF load location, a per-arch mmap_rnd() function is used to finding 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 does this witout the ARCH_BINFMT_ELF_RANDOMIZE_PIE logic). Signed-off-by: Kees Cook --- arch/Kconfig | 7 +++++++ arch/arm/Kconfig | 1 + arch/arm/mm/mmap.c | 4 ++-- arch/arm64/Kconfig | 1 + arch/arm64/mm/mmap.c | 4 ++-- arch/mips/Kconfig | 1 + arch/mips/mm/mmap.c | 9 ++++++--- arch/powerpc/Kconfig | 1 + arch/powerpc/mm/mmap.c | 4 ++-- arch/s390/Kconfig | 1 + arch/s390/mm/mmap.c | 8 ++++---- arch/x86/Kconfig | 1 + arch/x86/mm/mmap.c | 6 +++--- fs/binfmt_elf.c | 1 + include/linux/elf-randomize.h | 10 ++++++++++ 15 files changed, 43 insertions(+), 16 deletions(-) create mode 100644 include/linux/elf-randomize.h diff --git a/arch/Kconfig b/arch/Kconfig index 05d7a8a458d5..e315cc79ebe7 100644 --- a/arch/Kconfig +++ b/arch/Kconfig @@ -484,6 +484,13 @@ config HAVE_IRQ_EXIT_ON_IRQ_STACK This spares a stack switch and improves cache usage on softirq processing. +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(), must respect (current->flags & PF_RANDOMIZE) + # # ABI hall of shame # diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index 9f1f09a2bc9b..248d99cabaa8 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 0f8bc158f2c6..3c1fedb034bb 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 = 0UL; @@ -183,7 +183,7 @@ static unsigned long mmap_rnd(void) void arch_pick_mmap_layout(struct mm_struct *mm) { - unsigned long random_factor = mmap_rnd(); + unsigned long 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 1b8e97331ffb..5f469095e0e2 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 54922d1275b8..b7117cb4bc07 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 = 0; @@ -66,7 +66,7 @@ static unsigned long mmap_base(void) else if (gap > MAX_GAP) gap = MAX_GAP; - return PAGE_ALIGN(STACK_TOP - gap - mmap_rnd()); + return PAGE_ALIGN(STACK_TOP - gap - arch_mmap_rnd()); } /* diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig index c7a16904cd03..72ce5cece768 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 f1baadd56e82..d32490d99671 100644 --- a/arch/mips/mm/mmap.c +++ b/arch/mips/mm/mmap.c @@ -164,9 +164,12 @@ void arch_pick_mmap_layout(struct mm_struct *mm) } } -static inline unsigned long brk_rnd(void) +unsigned long arch_mmap_rnd(void) { - unsigned long rnd = get_random_int(); + unsigned long rnd = 0; + + if (current->flags & PF_RANDOMIZE) + rnd = get_random_int(); rnd = rnd << PAGE_SHIFT; /* 8MB for 32bit, 256MB for 64bit */ @@ -183,7 +186,7 @@ unsigned long arch_randomize_brk(struct mm_struct *mm) unsigned long base = mm->brk; unsigned long ret; - ret = PAGE_ALIGN(base + brk_rnd()); + ret = PAGE_ALIGN(base + arch_mmap_rnd()); if (ret < mm->brk) return mm->brk; diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig index 22b0940494bb..14fe1c411489 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 cb8bdbe4972f..d1111b49f03d 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 = 0; @@ -76,7 +76,7 @@ static inline unsigned long mmap_base(void) else if (gap > MAX_GAP) gap = MAX_GAP; - return PAGE_ALIGN(TASK_SIZE - gap - mmap_rnd()); + return PAGE_ALIGN(TASK_SIZE - gap - arch_mmap_rnd()); } /* diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig index 373cd5badf1c..4d707bb3e8dd 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 179a2c20b01f..77759e35671b 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 (!(current->flags & PF_RANDOMIZE)) return 0; @@ -72,7 +72,7 @@ static unsigned long mmap_rnd(void) static unsigned long mmap_base_legacy(void) { - return TASK_UNMAPPED_BASE + mmap_rnd(); + return TASK_UNMAPPED_BASE + arch_mmap_rnd(); } static inline unsigned long mmap_base(void) @@ -84,7 +84,7 @@ static inline unsigned long mmap_base(void) else if (gap > MAX_GAP) gap = MAX_GAP; gap &= PAGE_MASK; - return STACK_TOP - stack_maxrandom_size() - mmap_rnd() - gap; + return STACK_TOP - stack_maxrandom_size() - arch_mmap_rnd() - gap; } unsigned long @@ -187,7 +187,7 @@ unsigned long randomize_et_dyn(void) if (!is_32bit_task()) /* Align to 4GB */ base &= ~((1UL << 32) - 1); - return base + mmap_rnd(); + return base + arch_mmap_rnd(); } #ifndef CONFIG_64BIT diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index c2fb8a87dccb..9aa91727fbf8 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 df4552bd239e..a65e2b3154da 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 = 0; @@ -91,7 +91,7 @@ static unsigned long mmap_base(void) else if (gap > MAX_GAP) gap = MAX_GAP; - return PAGE_ALIGN(TASK_SIZE - gap - mmap_rnd()); + return PAGE_ALIGN(TASK_SIZE - gap - arch_mmap_rnd()); } /* @@ -103,7 +103,7 @@ static unsigned long mmap_legacy_base(void) if (mmap_is_ia32()) return TASK_UNMAPPED_BASE; else - return TASK_UNMAPPED_BASE + mmap_rnd(); + return TASK_UNMAPPED_BASE + arch_mmap_rnd(); } /* diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c index 995986b8e36b..b1c5ef5d9322 100644 --- a/fs/binfmt_elf.c +++ b/fs/binfmt_elf.c @@ -31,6 +31,7 @@ #include #include #include +#include #include #include #include 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 -- 1.9.1