xiaomi-sm8450/android_kernel_xiaomi_sm8450
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

VM: add "vm_mmap()" helper function

Browse Source 
This continues the theme started with vm_brk() and vm_munmap():
vm_mmap() does the same thing as do_mmap(), but additionally does the
required VM locking.

This uninlines (and rewrites it to be clearer) do_mmap(), which sadly
duplicates it in mm/mmap.c and mm/nommu.c.  But that way we don't have
to export our internal do_mmap_pgoff() function.

Some day we hopefully don't have to export do_mmap() either, if all
modular users can become the simpler vm_mmap() instead.  We're actually
very close to that already, with the notable exception of the (broken)
use in i810, and a couple of stragglers in binfmt_elf.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Linus Torvalds
2012-04-20 17:13:58 -07:00
parent a46ef99d80
commit 6be5ceb02e
15 changed files with 87 additions and 97 deletions
Download Patch File Download Diff File Expand all files Collapse all files

29
mm/mmap.c
View File

@@ -953,7 +953,7 @@ static inline unsigned long round_hint_to_min(unsigned long hint)
* The caller must hold down_write(&current->mm->mmap_sem).
*/
unsigned long do_mmap_pgoff(struct file *file, unsigned long addr,
static unsigned long do_mmap_pgoff(struct file *file, unsigned long addr,
unsigned long len, unsigned long prot,
unsigned long flags, unsigned long pgoff)
{
@@ -1089,7 +1089,32 @@ unsigned long do_mmap_pgoff(struct file *file, unsigned long addr,
return mmap_region(file, addr, len, flags, vm_flags, pgoff);
}
EXPORT_SYMBOL(do_mmap_pgoff);
unsigned long do_mmap(struct file *file, unsigned long addr,
unsigned long len, unsigned long prot,
unsigned long flag, unsigned long offset)
{
if (unlikely(offset + PAGE_ALIGN(len) < offset))
return -EINVAL;
if (unlikely(offset & ~PAGE_MASK))
return -EINVAL;
return do_mmap_pgoff(file, addr, len, prot, flag, offset >> PAGE_SHIFT);
}
EXPORT_SYMBOL(do_mmap);
unsigned long vm_mmap(struct file *file, unsigned long addr,
unsigned long len, unsigned long prot,
unsigned long flag, unsigned long offset)
{
unsigned long ret;
struct mm_struct *mm = current->mm;
down_write(&mm->mmap_sem);
ret = do_mmap(file, addr, len, prot, flag, offset);
up_write(&mm->mmap_sem);
return ret;
}
EXPORT_SYMBOL(vm_mmap);
SYSCALL_DEFINE6(mmap_pgoff, unsigned long, addr, unsigned long, len,
unsigned long, prot, unsigned long, flags,