From ae5758a1a7b7bdfdcfaf2d78a5a0f8675149dd79 Mon Sep 17 00:00:00 2001 From: Jan Beulich Date: Thu, 12 Dec 2013 17:12:22 -0800 Subject: [PATCH] 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 Cc: HATAYAMA Daisuke Cc: Alexey Dobriyan Cc: David S. Miller Cc: [3.12.x] Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/proc/inode.c | 14 +++++++++----- 1 file changed, 9 insertions(+), 5 deletions(-) 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 @@ proc_reg_get_unmapped_area(struct file *file, unsigned long orig_addr, { 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; -- 2.7.4