Commit fad1a86e authored Oct 16, 2013 by HATAYAMA Daisuke Committed by Linus Torvalds Oct 16, 2013

procfs: call default get_unmapped_area on MMU-present architectures



Commit c4fe2448 ("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>

parent 2cbe3b0a

fs/proc/inode.c

+6 −2

Original line number	Diff line number	Diff line
		@@ -289,8 +289,12 @@ 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)) {
		#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);

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