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authorOleg Nesterov <oleg@redhat.com>2009-07-10 03:27:38 +0200
committerJames Morris <jmorris@namei.org>2009-08-10 12:48:32 +0200
commit00f89d218523b9bf6b522349c039d5ac80aa536d (patch)
treecde7a8bde2798e4fb3ae28756f6cedd4db9191cc /fs/proc/task_mmu.c
parentmm_for_maps: simplify, use ptrace_may_access() (diff)
downloadlinux-00f89d218523b9bf6b522349c039d5ac80aa536d.tar.xz
linux-00f89d218523b9bf6b522349c039d5ac80aa536d.zip
mm_for_maps: shift down_read(mmap_sem) to the caller
mm_for_maps() takes ->mmap_sem after security checks, this looks strange and obfuscates the locking rules. Move this lock to its single caller, m_start(). Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Serge Hallyn <serue@us.ibm.com> Signed-off-by: James Morris <jmorris@namei.org>
Diffstat (limited to 'fs/proc/task_mmu.c')
-rw-r--r--fs/proc/task_mmu.c1
1 files changed, 1 insertions, 0 deletions
diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index 6f61b7cc32e0..9bd8be1d235c 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -119,6 +119,7 @@ static void *m_start(struct seq_file *m, loff_t *pos)
mm = mm_for_maps(priv->task);
if (!mm)
return NULL;
+ down_read(&mm->mmap_sem);
tail_vma = get_gate_vma(priv->task);
priv->tail_vma = tail_vma;