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procfs: call default get_unmapped_area on MMU-present architectures

Commit c4fe244857 ("sparc: fix PCI device proc file mmap(2)") added
proc_reg_get_unmapped_area in proc_reg_file_ops and
proc_reg_file_ops_no_compat, by which now mmap always returns EIO if
get_unmapped_area method is not defined for the target procfs file,
which causes regression of mmap on /proc/vmcore.

To address this issue, like get_unmapped_area(), call default
current->mm->get_unmapped_area on MMU-present architectures if
pde->proc_fops->get_unmapped_area, i.e.  the one in actual file
operation in the procfs file, is not defined.

Reported-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: HATAYAMA Daisuke <d.hatayama@jp.fujitsu.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: David S. Miller <davem@davemloft.net>
Tested-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
master
HATAYAMA Daisuke 8 years ago
committed by Linus Torvalds
parent
commit
fad1a86e25
  1. 8
      fs/proc/inode.c

8
fs/proc/inode.c

@ -289,9 +289,13 @@ static unsigned long proc_reg_get_unmapped_area(struct file *file, unsigned long
{
struct proc_dir_entry *pde = PDE(file_inode(file));
unsigned long rv = -EIO;
unsigned long (*get_unmapped_area)(struct file *, unsigned long, unsigned long, unsigned long, unsigned long);
unsigned long (*get_unmapped_area)(struct file *, unsigned long, unsigned long, unsigned long, unsigned long) = NULL;
if (use_pde(pde)) {
get_unmapped_area = pde->proc_fops->get_unmapped_area;
#ifdef CONFIG_MMU
get_unmapped_area = current->mm->get_unmapped_area;
#endif
if (pde->proc_fops->get_unmapped_area)
get_unmapped_area = pde->proc_fops->get_unmapped_area;
if (get_unmapped_area)
rv = get_unmapped_area(file, orig_addr, len, pgoff, flags);
unuse_pde(pde);

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