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author | 2015-08-04 12:17:53 -0700 | |
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committer | 2015-08-04 15:44:42 -0700 | |
commit | 9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 (patch) | |
tree | 1c9cafbcd35f783a87880a10f85d1a060db1a563 /kernel/arch/arm64/mm/mmap.c | |
parent | 98260f3884f4a202f9ca5eabed40b1354c489b29 (diff) |
Add the rt linux 4.1.3-rt3 as base
Import the rt linux 4.1.3-rt3 as OPNFV kvm base.
It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and
the base is:
commit 0917f823c59692d751951bf5ea699a2d1e2f26a2
Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Sat Jul 25 12:13:34 2015 +0200
Prepare v4.1.3-rt3
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
We lose all the git history this way and it's not good. We
should apply another opnfv project repo in future.
Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423
Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>
Diffstat (limited to 'kernel/arch/arm64/mm/mmap.c')
-rw-r--r-- | kernel/arch/arm64/mm/mmap.c | 138 |
1 files changed, 138 insertions, 0 deletions
diff --git a/kernel/arch/arm64/mm/mmap.c b/kernel/arch/arm64/mm/mmap.c new file mode 100644 index 000000000..ed177475d --- /dev/null +++ b/kernel/arch/arm64/mm/mmap.c @@ -0,0 +1,138 @@ +/* + * Based on arch/arm/mm/mmap.c + * + * Copyright (C) 2012 ARM Ltd. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see <http://www.gnu.org/licenses/>. + */ + +#include <linux/elf.h> +#include <linux/fs.h> +#include <linux/mm.h> +#include <linux/mman.h> +#include <linux/export.h> +#include <linux/shm.h> +#include <linux/sched.h> +#include <linux/io.h> +#include <linux/personality.h> +#include <linux/random.h> + +#include <asm/cputype.h> + +/* + * Leave enough space between the mmap area and the stack to honour ulimit in + * the face of randomisation. + */ +#define MIN_GAP (SZ_128M + ((STACK_RND_MASK << PAGE_SHIFT) + 1)) +#define MAX_GAP (STACK_TOP/6*5) + +static int mmap_is_legacy(void) +{ + if (current->personality & ADDR_COMPAT_LAYOUT) + return 1; + + if (rlimit(RLIMIT_STACK) == RLIM_INFINITY) + return 1; + + return sysctl_legacy_va_layout; +} + +unsigned long arch_mmap_rnd(void) +{ + unsigned long rnd; + + rnd = (unsigned long)get_random_int() & STACK_RND_MASK; + + return rnd << PAGE_SHIFT; +} + +static unsigned long mmap_base(unsigned long rnd) +{ + unsigned long gap = rlimit(RLIMIT_STACK); + + if (gap < MIN_GAP) + gap = MIN_GAP; + else if (gap > MAX_GAP) + gap = MAX_GAP; + + return PAGE_ALIGN(STACK_TOP - gap - rnd); +} + +/* + * This function, called very early during the creation of a new process VM + * image, sets up which VM layout function to use: + */ +void arch_pick_mmap_layout(struct mm_struct *mm) +{ + unsigned long random_factor = 0UL; + + if (current->flags & PF_RANDOMIZE) + random_factor = arch_mmap_rnd(); + + /* + * Fall back to the standard layout if the personality bit is set, or + * if the expected stack growth is unlimited: + */ + if (mmap_is_legacy()) { + mm->mmap_base = TASK_UNMAPPED_BASE + random_factor; + mm->get_unmapped_area = arch_get_unmapped_area; + } else { + mm->mmap_base = mmap_base(random_factor); + mm->get_unmapped_area = arch_get_unmapped_area_topdown; + } +} +EXPORT_SYMBOL_GPL(arch_pick_mmap_layout); + + +/* + * You really shouldn't be using read() or write() on /dev/mem. This might go + * away in the future. + */ +int valid_phys_addr_range(phys_addr_t addr, size_t size) +{ + if (addr < PHYS_OFFSET) + return 0; + if (addr + size > __pa(high_memory - 1) + 1) + return 0; + + return 1; +} + +/* + * Do not allow /dev/mem mappings beyond the supported physical range. + */ +int valid_mmap_phys_addr_range(unsigned long pfn, size_t size) +{ + return !(((pfn << PAGE_SHIFT) + size) & ~PHYS_MASK); +} + +#ifdef CONFIG_STRICT_DEVMEM + +#include <linux/ioport.h> + +/* + * devmem_is_allowed() checks to see if /dev/mem access to a certain address + * is valid. The argument is a physical page number. We mimic x86 here by + * disallowing access to system RAM as well as device-exclusive MMIO regions. + * This effectively disable read()/write() on /dev/mem. + */ +int devmem_is_allowed(unsigned long pfn) +{ + if (iomem_is_exclusive(pfn << PAGE_SHIFT)) + return 0; + if (!page_is_ram(pfn)) + return 1; + return 0; +} + +#endif |