procfs: also fix proc_reg_get_unmapped_area() for !MMU case
Commit fad1a86e25e0 ("procfs: call default get_unmapped_area on
MMU-present architectures"), as its title says, took care of only the
MMU case, leaving the !MMU side still in the regressed state (returning
-EIO in all cases where pde->proc_fops->get_unmapped_area is NULL).
From the fad1a86e25e0 changelog:
"Commit c4fe24485729 ("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"
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Cc: HATAYAMA Daisuke <d.hatayama@jp.fujitsu.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: <stable@vger.kernel.org> [3.12.x]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/proc/inode.c b/fs/proc/inode.c
index 28955d4..124fc43 100644
--- a/fs/proc/inode.c
+++ b/fs/proc/inode.c
@@ -292,16 +292,20 @@
{
struct proc_dir_entry *pde = PDE(file_inode(file));
unsigned long rv = -EIO;
- unsigned long (*get_area)(struct file *, unsigned long, unsigned long,
- unsigned long, unsigned long) = NULL;
+
if (use_pde(pde)) {
+ typeof(proc_reg_get_unmapped_area) *get_area;
+
+ get_area = pde->proc_fops->get_unmapped_area;
#ifdef CONFIG_MMU
- get_area = current->mm->get_unmapped_area;
+ if (!get_area)
+ get_area = current->mm->get_unmapped_area;
#endif
- if (pde->proc_fops->get_unmapped_area)
- get_area = pde->proc_fops->get_unmapped_area;
+
if (get_area)
rv = get_area(file, orig_addr, len, pgoff, flags);
+ else
+ rv = orig_addr;
unuse_pde(pde);
}
return rv;