redonkable/remarkable-linux
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sysfs: only access bin file vm_ops with the active lock

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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>
This commit is contained in:
Eric W. Biederman 2010-09-20 00:57:03 -07:00 committed by Greg Kroah-Hartman
parent a6849fa1f7
commit 38f49a5132
1 changed files with 26 additions and 16 deletions
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42
fs/sysfs/bin.c
View file

@ -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;