2005-04-17 00:20:36 +02:00
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/*
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* linux/arch/arm/mm/mmap.c
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*/
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#include <linux/fs.h>
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#include <linux/mm.h>
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#include <linux/mman.h>
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#include <linux/shm.h>
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Detach sched.h from mm.h
First thing mm.h does is including sched.h solely for can_do_mlock() inline
function which has "current" dereference inside. By dealing with can_do_mlock()
mm.h can be detached from sched.h which is good. See below, why.
This patch
a) removes unconditional inclusion of sched.h from mm.h
b) makes can_do_mlock() normal function in mm/mlock.c
c) exports can_do_mlock() to not break compilation
d) adds sched.h inclusions back to files that were getting it indirectly.
e) adds less bloated headers to some files (asm/signal.h, jiffies.h) that were
getting them indirectly
Net result is:
a) mm.h users would get less code to open, read, preprocess, parse, ... if
they don't need sched.h
b) sched.h stops being dependency for significant number of files:
on x86_64 allmodconfig touching sched.h results in recompile of 4083 files,
after patch it's only 3744 (-8.3%).
Cross-compile tested on
all arm defconfigs, all mips defconfigs, all powerpc defconfigs,
alpha alpha-up
arm
i386 i386-up i386-defconfig i386-allnoconfig
ia64 ia64-up
m68k
mips
parisc parisc-up
powerpc powerpc-up
s390 s390-up
sparc sparc-up
sparc64 sparc64-up
um-x86_64
x86_64 x86_64-up x86_64-defconfig x86_64-allnoconfig
as well as my two usual configs.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-20 23:22:52 +02:00
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#include <linux/sched.h>
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2008-09-05 15:08:44 +02:00
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#include <linux/io.h>
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2011-04-13 05:57:17 +02:00
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#include <linux/personality.h>
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2010-06-15 03:16:19 +02:00
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#include <linux/random.h>
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2011-11-22 04:01:06 +01:00
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#include <asm/cachetype.h>
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2005-04-17 00:20:36 +02:00
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#define COLOUR_ALIGN(addr,pgoff) \
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((((addr)+SHMLBA-1)&~(SHMLBA-1)) + \
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(((pgoff)<<PAGE_SHIFT) & (SHMLBA-1)))
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2011-11-22 04:01:07 +01:00
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/* gap between mmap and stack */
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#define MIN_GAP (128*1024*1024UL)
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#define MAX_GAP ((TASK_SIZE)/6*5)
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static int mmap_is_legacy(void)
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{
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if (current->personality & ADDR_COMPAT_LAYOUT)
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return 1;
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if (rlimit(RLIMIT_STACK) == RLIM_INFINITY)
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return 1;
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return sysctl_legacy_va_layout;
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}
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static unsigned long mmap_base(unsigned long rnd)
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{
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unsigned long gap = rlimit(RLIMIT_STACK);
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if (gap < MIN_GAP)
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gap = MIN_GAP;
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else if (gap > MAX_GAP)
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gap = MAX_GAP;
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return PAGE_ALIGN(TASK_SIZE - gap - rnd);
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}
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2005-04-17 00:20:36 +02:00
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/*
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* We need to ensure that shared mappings are correctly aligned to
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* avoid aliasing issues with VIPT caches. We need to ensure that
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* a specific page of an object is always mapped at a multiple of
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* SHMLBA bytes.
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*
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* We unconditionally provide this function for all cases, however
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* in the VIVT case, we optimise out the alignment rules.
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*/
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unsigned long
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arch_get_unmapped_area(struct file *filp, unsigned long addr,
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unsigned long len, unsigned long pgoff, unsigned long flags)
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{
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struct mm_struct *mm = current->mm;
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struct vm_area_struct *vma;
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2011-11-22 04:01:06 +01:00
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int do_align = 0;
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int aliasing = cache_is_vipt_aliasing();
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2012-12-12 01:02:10 +01:00
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struct vm_unmapped_area_info info;
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2005-04-17 00:20:36 +02:00
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/*
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* We only need to do colour alignment if either the I or D
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2011-11-22 04:01:06 +01:00
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* caches alias.
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2005-04-17 00:20:36 +02:00
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*/
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2011-11-22 04:01:06 +01:00
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if (aliasing)
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do_align = filp || (flags & MAP_SHARED);
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2005-04-17 00:20:36 +02:00
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/*
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2007-05-06 23:50:07 +02:00
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* We enforce the MAP_FIXED case.
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2005-04-17 00:20:36 +02:00
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*/
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if (flags & MAP_FIXED) {
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2009-12-05 21:10:44 +01:00
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if (aliasing && flags & MAP_SHARED &&
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(addr - (pgoff << PAGE_SHIFT)) & (SHMLBA - 1))
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2005-04-17 00:20:36 +02:00
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return -EINVAL;
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return addr;
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}
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if (len > TASK_SIZE)
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return -ENOMEM;
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if (addr) {
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if (do_align)
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addr = COLOUR_ALIGN(addr, pgoff);
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else
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addr = PAGE_ALIGN(addr);
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vma = find_vma(mm, addr);
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if (TASK_SIZE - len >= addr &&
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(!vma || addr + len <= vma->vm_start))
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return addr;
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}
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2012-12-12 01:02:10 +01:00
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info.flags = 0;
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info.length = len;
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info.low_limit = mm->mmap_base;
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info.high_limit = TASK_SIZE;
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info.align_mask = do_align ? (PAGE_MASK & (SHMLBA - 1)) : 0;
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info.align_offset = pgoff << PAGE_SHIFT;
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return vm_unmapped_area(&info);
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2005-04-17 00:20:36 +02:00
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}
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2011-11-22 04:01:07 +01:00
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unsigned long
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arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0,
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const unsigned long len, const unsigned long pgoff,
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const unsigned long flags)
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{
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struct vm_area_struct *vma;
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struct mm_struct *mm = current->mm;
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unsigned long addr = addr0;
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int do_align = 0;
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int aliasing = cache_is_vipt_aliasing();
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2012-12-12 01:02:10 +01:00
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struct vm_unmapped_area_info info;
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2011-11-22 04:01:07 +01:00
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/*
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* We only need to do colour alignment if either the I or D
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* caches alias.
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*/
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if (aliasing)
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do_align = filp || (flags & MAP_SHARED);
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/* requested length too big for entire address space */
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if (len > TASK_SIZE)
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return -ENOMEM;
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if (flags & MAP_FIXED) {
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if (aliasing && flags & MAP_SHARED &&
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(addr - (pgoff << PAGE_SHIFT)) & (SHMLBA - 1))
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return -EINVAL;
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return addr;
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}
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/* requesting a specific address */
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if (addr) {
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if (do_align)
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addr = COLOUR_ALIGN(addr, pgoff);
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else
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addr = PAGE_ALIGN(addr);
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vma = find_vma(mm, addr);
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if (TASK_SIZE - len >= addr &&
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(!vma || addr + len <= vma->vm_start))
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return addr;
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}
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2012-12-12 01:02:10 +01:00
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info.flags = VM_UNMAPPED_AREA_TOPDOWN;
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info.length = len;
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info.low_limit = PAGE_SIZE;
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info.high_limit = mm->mmap_base;
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info.align_mask = do_align ? (PAGE_MASK & (SHMLBA - 1)) : 0;
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info.align_offset = pgoff << PAGE_SHIFT;
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addr = vm_unmapped_area(&info);
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2011-11-22 04:01:07 +01:00
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/*
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* A failed mmap() very likely causes application failure,
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* so fall back to the bottom-up function here. This scenario
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* can happen with large stack limits and large mmap()
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* allocations.
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*/
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2012-12-12 01:02:10 +01:00
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if (addr & ~PAGE_MASK) {
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VM_BUG_ON(addr != -ENOMEM);
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info.flags = 0;
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info.low_limit = mm->mmap_base;
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info.high_limit = TASK_SIZE;
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addr = vm_unmapped_area(&info);
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}
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2011-11-22 04:01:07 +01:00
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return addr;
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}
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void arch_pick_mmap_layout(struct mm_struct *mm)
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{
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unsigned long random_factor = 0UL;
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/* 8 bits of randomness in 20 address space bits */
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if ((current->flags & PF_RANDOMIZE) &&
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!(current->personality & ADDR_NO_RANDOMIZE))
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random_factor = (get_random_int() % (1 << 8)) << PAGE_SHIFT;
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if (mmap_is_legacy()) {
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mm->mmap_base = TASK_UNMAPPED_BASE + random_factor;
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mm->get_unmapped_area = arch_get_unmapped_area;
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mm->unmap_area = arch_unmap_area;
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} else {
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mm->mmap_base = mmap_base(random_factor);
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mm->get_unmapped_area = arch_get_unmapped_area_topdown;
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mm->unmap_area = arch_unmap_area_topdown;
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}
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}
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2006-09-16 11:50:22 +02:00
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/*
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* You really shouldn't be using read() or write() on /dev/mem. This
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* might go away in the future.
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*/
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2012-09-12 20:05:58 +02:00
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int valid_phys_addr_range(phys_addr_t addr, size_t size)
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2006-09-16 11:50:22 +02:00
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{
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2008-02-26 18:42:10 +01:00
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if (addr < PHYS_OFFSET)
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return 0;
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2009-10-02 01:45:28 +02:00
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if (addr + size > __pa(high_memory - 1) + 1)
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2006-09-16 11:50:22 +02:00
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return 0;
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return 1;
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}
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/*
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* We don't use supersection mappings for mmap() on /dev/mem, which
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* means that we can't map the memory area above the 4G barrier into
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* userspace.
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*/
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int valid_mmap_phys_addr_range(unsigned long pfn, size_t size)
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{
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return !(pfn + (size >> PAGE_SHIFT) > 0x00100000);
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}
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2010-09-23 00:34:36 +02:00
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#ifdef CONFIG_STRICT_DEVMEM
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#include <linux/ioport.h>
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/*
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* devmem_is_allowed() checks to see if /dev/mem access to a certain
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* address is valid. The argument is a physical page number.
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* We mimic x86 here by disallowing access to system RAM as well as
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* device-exclusive MMIO regions. This effectively disable read()/write()
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* on /dev/mem.
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*/
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int devmem_is_allowed(unsigned long pfn)
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{
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if (iomem_is_exclusive(pfn << PAGE_SHIFT))
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return 0;
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if (!page_is_ram(pfn))
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return 1;
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return 0;
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}
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#endif
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