diff options
Diffstat (limited to 'mm/fremap.c')
| -rw-r--r-- | mm/fremap.c | 24 |
1 files changed, 13 insertions, 11 deletions
diff --git a/mm/fremap.c b/mm/fremap.c index 37a93f8f3ae..14bd3bf7826 100644 --- a/mm/fremap.c +++ b/mm/fremap.c @@ -97,26 +97,28 @@ static int populate_range(struct mm_struct *mm, struct vm_area_struct *vma, } -/*** - * sys_remap_file_pages - remap arbitrary pages of a shared backing store - * file within an existing vma. +/** + * sys_remap_file_pages - remap arbitrary pages of an existing VM_SHARED vma * @start: start of the remapped virtual memory range * @size: size of the remapped virtual memory range - * @prot: new protection bits of the range - * @pgoff: to be mapped page of the backing store file + * @prot: new protection bits of the range (see NOTE) + * @pgoff: to-be-mapped page of the backing store file * @flags: 0 or MAP_NONBLOCKED - the later will cause no IO. * - * this syscall works purely via pagetables, so it's the most efficient + * sys_remap_file_pages remaps arbitrary pages of an existing VM_SHARED vma + * (shared backing store file). + * + * This syscall works purely via pagetables, so it's the most efficient * way to map the same (large) file into a given virtual window. Unlike * mmap()/mremap() it does not create any new vmas. The new mappings are * also safe across swapout. * - * NOTE: the 'prot' parameter right now is ignored, and the vma's default - * protection is used. Arbitrary protections might be implemented in the - * future. + * NOTE: the 'prot' parameter right now is ignored (but must be zero), + * and the vma's default protection is used. Arbitrary protections + * might be implemented in the future. */ asmlinkage long sys_remap_file_pages(unsigned long start, unsigned long size, - unsigned long __prot, unsigned long pgoff, unsigned long flags) + unsigned long prot, unsigned long pgoff, unsigned long flags) { struct mm_struct *mm = current->mm; struct address_space *mapping; @@ -125,7 +127,7 @@ asmlinkage long sys_remap_file_pages(unsigned long start, unsigned long size, int err = -EINVAL; int has_write_lock = 0; - if (__prot) + if (prot) return err; /* * Sanitize the syscall parameters: |