summaryrefslogtreecommitdiff
path: root/fs/sysfs
diff options
context:
space:
mode:
authorEric W. Biederman <ebiederm@aristanetworks.com>2010-09-20 00:57:03 -0700
committerGreg Kroah-Hartman <gregkh@suse.de>2010-10-22 10:16:43 -0700
commit38f49a5132f24d29236820eb5c7dd956e47f94a3 (patch)
treeeb2d3184996d01babcf3689dd20d626f731d340a /fs/sysfs
parenta6849fa1f7d7d7adbeb6a696beeabfa078acf173 (diff)
downloadlwn-38f49a5132f24d29236820eb5c7dd956e47f94a3.tar.gz
lwn-38f49a5132f24d29236820eb5c7dd956e47f94a3.zip
sysfs: only access bin file vm_ops with the active lock
bb->vm_ops is a cached copy of the vm_ops of the underlying sysfs bin file, which means that after sysfs_bin_remove_file completes it is only longer valid to deference bb->vm_ops. So move all of the tests of bb->vm_ops inside of where we hold the sysfs active lock. Signed-off-by: Eric W. Biederman <ebiederm@aristanetworks.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'fs/sysfs')
-rw-r--r--fs/sysfs/bin.c42
1 files changed, 26 insertions, 16 deletions
diff --git a/fs/sysfs/bin.c b/fs/sysfs/bin.c
index d31d7b7d5426..a4759833d62d 100644
--- a/fs/sysfs/bin.c
+++ b/fs/sysfs/bin.c
@@ -179,13 +179,14 @@ static void bin_vma_open(struct vm_area_struct *vma)
struct bin_buffer *bb = file->private_data;
struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata;
- if (!bb->vm_ops || !bb->vm_ops->open)
+ if (!bb->vm_ops)
return;
if (!sysfs_get_active(attr_sd))
return;
- bb->vm_ops->open(vma);
+ if (bb->vm_ops->open)
+ bb->vm_ops->open(vma);
sysfs_put_active(attr_sd);
}
@@ -197,13 +198,15 @@ static int bin_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata;
int ret;
- if (!bb->vm_ops || !bb->vm_ops->fault)
+ if (!bb->vm_ops)
return VM_FAULT_SIGBUS;
if (!sysfs_get_active(attr_sd))
return VM_FAULT_SIGBUS;
- ret = bb->vm_ops->fault(vma, vmf);
+ ret = VM_FAULT_SIGBUS;
+ if (bb->vm_ops->fault)
+ ret = bb->vm_ops->fault(vma, vmf);
sysfs_put_active(attr_sd);
return ret;
@@ -219,13 +222,12 @@ static int bin_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
if (!bb->vm_ops)
return VM_FAULT_SIGBUS;
- if (!bb->vm_ops->page_mkwrite)
- return 0;
-
if (!sysfs_get_active(attr_sd))
return VM_FAULT_SIGBUS;
- ret = bb->vm_ops->page_mkwrite(vma, vmf);
+ ret = 0;
+ if (bb->vm_ops->page_mkwrite)
+ ret = bb->vm_ops->page_mkwrite(vma, vmf);
sysfs_put_active(attr_sd);
return ret;
@@ -239,13 +241,15 @@ static int bin_access(struct vm_area_struct *vma, unsigned long addr,
struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata;
int ret;
- if (!bb->vm_ops || !bb->vm_ops->access)
+ if (!bb->vm_ops)
return -EINVAL;
if (!sysfs_get_active(attr_sd))
return -EINVAL;
- ret = bb->vm_ops->access(vma, addr, buf, len, write);
+ ret = -EINVAL;
+ if (bb->vm_ops->access)
+ ret = bb->vm_ops->access(vma, addr, buf, len, write);
sysfs_put_active(attr_sd);
return ret;
@@ -259,13 +263,15 @@ static int bin_set_policy(struct vm_area_struct *vma, struct mempolicy *new)
struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata;
int ret;
- if (!bb->vm_ops || !bb->vm_ops->set_policy)
+ if (!bb->vm_ops)
return 0;
if (!sysfs_get_active(attr_sd))
return -EINVAL;
- ret = bb->vm_ops->set_policy(vma, new);
+ ret = 0;
+ if (bb->vm_ops->set_policy)
+ ret = bb->vm_ops->set_policy(vma, new);
sysfs_put_active(attr_sd);
return ret;
@@ -279,13 +285,15 @@ static struct mempolicy *bin_get_policy(struct vm_area_struct *vma,
struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata;
struct mempolicy *pol;
- if (!bb->vm_ops || !bb->vm_ops->get_policy)
+ if (!bb->vm_ops)
return vma->vm_policy;
if (!sysfs_get_active(attr_sd))
return vma->vm_policy;
- pol = bb->vm_ops->get_policy(vma, addr);
+ pol = vma->vm_policy;
+ if (bb->vm_ops->get_policy)
+ pol = bb->vm_ops->get_policy(vma, addr);
sysfs_put_active(attr_sd);
return pol;
@@ -299,13 +307,15 @@ static int bin_migrate(struct vm_area_struct *vma, const nodemask_t *from,
struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata;
int ret;
- if (!bb->vm_ops || !bb->vm_ops->migrate)
+ if (!bb->vm_ops)
return 0;
if (!sysfs_get_active(attr_sd))
return 0;
- ret = bb->vm_ops->migrate(vma, from, to, flags);
+ ret = 0;
+ if (bb->vm_ops->migrate)
+ ret = bb->vm_ops->migrate(vma, from, to, flags);
sysfs_put_active(attr_sd);
return ret;