From 18d98a79382cbe5a7569788d5b7b18e7015506f2 Mon Sep 17 00:00:00 2001 From: Helge Deller Date: Sun, 16 Oct 2016 00:02:27 +0200 Subject: [PATCH] parisc: Enable KASLR Add missing code for userspace executable address randomization, e.g. applications compiled with the gcc -pie option. Signed-off-by: Helge Deller --- arch/parisc/Kconfig | 1 + arch/parisc/include/asm/elf.h | 7 ++++--- arch/parisc/kernel/process.c | 6 +----- arch/parisc/kernel/sys_parisc.c | 18 ++++++++---------- 4 files changed, 14 insertions(+), 18 deletions(-) diff --git a/arch/parisc/Kconfig b/arch/parisc/Kconfig index a14b86587013..3a71f38cdc05 100644 --- a/arch/parisc/Kconfig +++ b/arch/parisc/Kconfig @@ -7,6 +7,7 @@ config PARISC select HAVE_FUNCTION_GRAPH_TRACER select HAVE_SYSCALL_TRACEPOINTS select ARCH_WANT_FRAME_POINTERS + select ARCH_HAS_ELF_RANDOMIZE select RTC_CLASS select RTC_DRV_GENERIC select INIT_ALL_POSSIBLE diff --git a/arch/parisc/include/asm/elf.h b/arch/parisc/include/asm/elf.h index 78c9fd32c554..a6b2a421571e 100644 --- a/arch/parisc/include/asm/elf.h +++ b/arch/parisc/include/asm/elf.h @@ -348,9 +348,10 @@ struct pt_regs; /* forward declaration... */ #define ELF_HWCAP 0 -#define STACK_RND_MASK (is_32bit_task() ? \ - 0x7ff >> (PAGE_SHIFT - 12) : \ - 0x3ffff >> (PAGE_SHIFT - 12)) +/* Masks for stack and mmap randomization */ +#define BRK_RND_MASK (is_32bit_task() ? 0x07ffUL : 0x3ffffUL) +#define MMAP_RND_MASK (is_32bit_task() ? 0x1fffUL : 0x3ffffUL) +#define STACK_RND_MASK MMAP_RND_MASK struct mm_struct; extern unsigned long arch_randomize_brk(struct mm_struct *); diff --git a/arch/parisc/kernel/process.c b/arch/parisc/kernel/process.c index 40639439d8b3..ea6603ee8d24 100644 --- a/arch/parisc/kernel/process.c +++ b/arch/parisc/kernel/process.c @@ -276,11 +276,7 @@ void *dereference_function_descriptor(void *ptr) static inline unsigned long brk_rnd(void) { - /* 8MB for 32bit, 1GB for 64bit */ - if (is_32bit_task()) - return (get_random_int() & 0x7ffUL) << PAGE_SHIFT; - else - return (get_random_int() & 0x3ffffUL) << PAGE_SHIFT; + return (get_random_int() & BRK_RND_MASK) << PAGE_SHIFT; } unsigned long arch_randomize_brk(struct mm_struct *mm) diff --git a/arch/parisc/kernel/sys_parisc.c b/arch/parisc/kernel/sys_parisc.c index 0a393a04e891..a81e177cac7b 100644 --- a/arch/parisc/kernel/sys_parisc.c +++ b/arch/parisc/kernel/sys_parisc.c @@ -225,19 +225,17 @@ static unsigned long mmap_rnd(void) { unsigned long rnd = 0; - /* - * 8 bits of randomness in 32bit mmaps, 20 address space bits - * 28 bits of randomness in 64bit mmaps, 40 address space bits - */ - if (current->flags & PF_RANDOMIZE) { - if (is_32bit_task()) - rnd = get_random_int() % (1<<8); - else - rnd = get_random_int() % (1<<28); - } + if (current->flags & PF_RANDOMIZE) + rnd = get_random_int() & MMAP_RND_MASK; + return rnd << PAGE_SHIFT; } +unsigned long arch_mmap_rnd(void) +{ + return (get_random_int() & MMAP_RND_MASK) << PAGE_SHIFT; +} + static unsigned long mmap_legacy_base(void) { return TASK_UNMAPPED_BASE + mmap_rnd(); -- 2.39.2