]> git.karo-electronics.de Git - linux-beck.git/commit
procfs task exe symlink
authorMatt Helsley <matthltc@us.ibm.com>
Tue, 29 Apr 2008 08:01:36 +0000 (01:01 -0700)
committerLinus Torvalds <torvalds@linux-foundation.org>
Tue, 29 Apr 2008 15:06:17 +0000 (08:06 -0700)
commit925d1c401fa6cfd0df5d2e37da8981494ccdec07
tree4f3b7a09311cd99783b822350628125e44f9902d
parente93b4ea20adb20f1f1f07f10ba5d7dd739d2843e
procfs task exe symlink

The kernel implements readlink of /proc/pid/exe by getting the file from
the first executable VMA.  Then the path to the file is reconstructed and
reported as the result.

Because of the VMA walk the code is slightly different on nommu systems.
This patch avoids separate /proc/pid/exe code on nommu systems.  Instead of
walking the VMAs to find the first executable file-backed VMA we store a
reference to the exec'd file in the mm_struct.

That reference would prevent the filesystem holding the executable file
from being unmounted even after unmapping the VMAs.  So we track the number
of VM_EXECUTABLE VMAs and drop the new reference when the last one is
unmapped.  This avoids pinning the mounted filesystem.

[akpm@linux-foundation.org: improve comments]
[yamamoto@valinux.co.jp: fix dup_mmap]
Signed-off-by: Matt Helsley <matthltc@us.ibm.com>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Cc: David Howells <dhowells@redhat.com>
Cc:"Eric W. Biederman" <ebiederm@xmission.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Hugh Dickins <hugh@veritas.com>
Signed-off-by: YAMAMOTO Takashi <yamamoto@valinux.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
12 files changed:
fs/binfmt_flat.c
fs/exec.c
fs/proc/base.c
fs/proc/internal.h
fs/proc/task_mmu.c
fs/proc/task_nommu.c
include/linux/mm.h
include/linux/mm_types.h
include/linux/proc_fs.h
kernel/fork.c
mm/mmap.c
mm/nommu.c