Commit 2cbe3b0a authored Oct 16, 2013 by HATAYAMA Daisuke Committed by Linus Torvalds Oct 16, 2013

procfs: fix unintended truncation of returned mapped address



Currently, proc_reg_get_unmapped_area truncates upper 32-bit of the
mapped virtual address returned from get_unmapped_area method in
pde->proc_fops due to the variable rv of signed integer on x86_64.  This
is too small to have vitual address of unsigned long on x86_64 since on
x86_64, signed integer is of 4 bytes while unsigned long is of 8 bytes.
To fix this issue, use unsigned long instead.

Fixes a regression added in commit c4fe2448 ("sparc: fix PCI device
proc file mmap(2)").

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 e3b6c655

fs/proc/inode.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -288,7 +288,7 @@ static int proc_reg_mmap(struct file file, struct vm_area_struct vma)
		static unsigned long proc_reg_get_unmapped_area(struct file *file, unsigned long orig_addr, unsigned long len, unsigned long pgoff, unsigned long flags)
		{
		struct proc_dir_entry *pde = PDE(file_inode(file));
		int rv = -EIO;
		unsigned long rv = -EIO;
		unsigned long (get_unmapped_area)(struct file , unsigned long, unsigned long, unsigned long, unsigned long);
		if (use_pde(pde)) {
		get_unmapped_area = pde->proc_fops->get_unmapped_area;

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