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-rw-r--r--sys/fs/pseudofs/pseudofs_vnops.c94
1 files changed, 44 insertions, 50 deletions
diff --git a/sys/fs/pseudofs/pseudofs_vnops.c b/sys/fs/pseudofs/pseudofs_vnops.c
index ad221f1..556707c 100644
--- a/sys/fs/pseudofs/pseudofs_vnops.c
+++ b/sys/fs/pseudofs/pseudofs_vnops.c
@@ -81,13 +81,14 @@ SYSCTL_INT(_vfs_pfs, OID_AUTO, trace, CTLFLAG_RW, &pfs_trace, 0,
#endif
/*
- * Returns non-zero if given file is visible to given process
+ * Returns non-zero if given file is visible to given process. If the 'p'
+ * parameter is non-NULL, then it will hold a pointer to the process the
+ * given file belongs to on return and the process will be locked.
*/
static int
-pfs_visible(struct thread *td, struct pfs_node *pn, pid_t pid)
+pfs_visible(struct thread *td, struct pfs_node *pn, pid_t pid, struct proc **p)
{
struct proc *proc;
- int r;
PFS_TRACE(("%s (pid: %d, req: %d)",
pn->pn_name, pid, td->td_proc->p_pid));
@@ -95,16 +96,23 @@ pfs_visible(struct thread *td, struct pfs_node *pn, pid_t pid)
if (pn->pn_flags & PFS_DISABLED)
PFS_RETURN (0);
- r = 1;
if (pid != NO_PID) {
if ((proc = pfind(pid)) == NULL)
PFS_RETURN (0);
if (p_cansee(td, proc) != 0 ||
- (pn->pn_vis != NULL && !(pn->pn_vis)(td, proc, pn)))
- r = 0;
- PROC_UNLOCK(proc);
- }
- PFS_RETURN (r);
+ (pn->pn_vis != NULL && !(pn->pn_vis)(td, proc, pn))) {
+ PROC_UNLOCK(proc);
+ PFS_RETURN (0);
+ }
+ if (p) {
+ /* We return with the process locked to avoid races. */
+ *p = proc;
+ } else
+ PROC_UNLOCK(proc);
+ } else
+ if (p)
+ *p = NULL;
+ PFS_RETURN (1);
}
/*
@@ -176,7 +184,7 @@ pfs_getattr(struct vop_getattr_args *va)
PFS_TRACE((pn->pn_name));
- if (!pfs_visible(curthread, pn, pvd->pvd_pid))
+ if (!pfs_visible(curthread, pn, pvd->pvd_pid, &proc))
PFS_RETURN (ENOENT);
VATTR_NULL(vap);
@@ -206,9 +214,7 @@ pfs_getattr(struct vop_getattr_args *va)
break;
}
- if (pvd->pvd_pid != NO_PID) {
- if ((proc = pfind(pvd->pvd_pid)) == NULL)
- PFS_RETURN (ENOENT);
+ if (proc != NULL) {
vap->va_uid = proc->p_ucred->cr_ruid;
vap->va_gid = proc->p_ucred->cr_rgid;
if (pn->pn_attr != NULL)
@@ -231,7 +237,7 @@ pfs_ioctl(struct vop_ioctl_args *va)
struct vnode *vn = va->a_vp;
struct pfs_vdata *pvd = (struct pfs_vdata *)vn->v_data;
struct pfs_node *pn = pvd->pvd_pn;
- struct proc *proc = NULL;
+ struct proc *proc;
int error;
PFS_TRACE(("%s: %lx", pn->pn_name, va->a_command));
@@ -246,13 +252,10 @@ pfs_ioctl(struct vop_ioctl_args *va)
* This is necessary because process' privileges may
* have changed since the open() call.
*/
- if (!pfs_visible(curthread, pn, pvd->pvd_pid))
+ if (!pfs_visible(curthread, pn, pvd->pvd_pid, &proc))
PFS_RETURN (EIO);
- /* XXX duplicates bits of pfs_visible() */
- if (pvd->pvd_pid != NO_PID) {
- if ((proc = pfind(pvd->pvd_pid)) == NULL)
- PFS_RETURN (EIO);
+ if (proc != NULL) {
_PHOLD(proc);
PROC_UNLOCK(proc);
}
@@ -274,28 +277,25 @@ pfs_getextattr(struct vop_getextattr_args *va)
struct vnode *vn = va->a_vp;
struct pfs_vdata *pvd = (struct pfs_vdata *)vn->v_data;
struct pfs_node *pn = pvd->pvd_pn;
- struct proc *proc = NULL;
+ struct proc *proc;
int error;
PFS_TRACE((pn->pn_name));
- if (!pfs_visible(curthread, pn, pvd->pvd_pid))
- PFS_RETURN (ENOENT);
-
- if (pn->pn_getextattr == NULL)
- PFS_RETURN (EOPNOTSUPP);
-
/*
* This is necessary because either process' privileges may
* have changed since the open() call.
*/
- if (!pfs_visible(curthread, pn, pvd->pvd_pid))
+ if (!pfs_visible(curthread, pn, pvd->pvd_pid, &proc))
PFS_RETURN (EIO);
- /* XXX duplicates bits of pfs_visible() */
- if (pvd->pvd_pid != NO_PID) {
- if ((proc = pfind(pvd->pvd_pid)) == NULL)
- PFS_RETURN (EIO);
+ if (pn->pn_getextattr == NULL) {
+ if (proc != NULL)
+ PROC_UNLOCK(proc);
+ PFS_RETURN (EOPNOTSUPP);
+ }
+
+ if (proc != NULL) {
_PHOLD(proc);
PROC_UNLOCK(proc);
}
@@ -347,8 +347,8 @@ pfs_lookup(struct vop_cachedlookup_args *va)
if (cnp->cn_namelen >= PFS_NAMELEN)
PFS_RETURN (ENOENT);
- /* check that parent directory is visisble... */
- if (!pfs_visible(curthread, pd, pvd->pvd_pid))
+ /* check that parent directory is visible... */
+ if (!pfs_visible(curthread, pd, pvd->pvd_pid, NULL))
PFS_RETURN (ENOENT);
/* self */
@@ -404,7 +404,7 @@ pfs_lookup(struct vop_cachedlookup_args *va)
got_pnode:
if (pn != pd->pn_parent && !pn->pn_parent)
pn->pn_parent = pd;
- if (!pfs_visible(curthread, pn, pvd->pvd_pid)) {
+ if (!pfs_visible(curthread, pn, pvd->pvd_pid, NULL)) {
error = ENOENT;
goto failed;
}
@@ -447,7 +447,7 @@ pfs_open(struct vop_open_args *va)
* XXX and the only consequence of that race is an EIO further
* XXX down the line.
*/
- if (!pfs_visible(va->a_td, pn, pvd->pvd_pid))
+ if (!pfs_visible(va->a_td, pn, pvd->pvd_pid, NULL))
PFS_RETURN (ENOENT);
/* check if the requested mode is permitted */
@@ -472,7 +472,7 @@ pfs_read(struct vop_read_args *va)
struct pfs_vdata *pvd = (struct pfs_vdata *)vn->v_data;
struct pfs_node *pn = pvd->pvd_pn;
struct uio *uio = va->a_uio;
- struct proc *proc = NULL;
+ struct proc *proc;
struct sbuf *sb = NULL;
int error;
unsigned int buflen, offset, resid;
@@ -492,13 +492,10 @@ pfs_read(struct vop_read_args *va)
* This is necessary because either process' privileges may
* have changed since the open() call.
*/
- if (!pfs_visible(curthread, pn, pvd->pvd_pid))
+ if (!pfs_visible(curthread, pn, pvd->pvd_pid, &proc))
PFS_RETURN (EIO);
- /* XXX duplicates bits of pfs_visible() */
- if (pvd->pvd_pid != NO_PID) {
- if ((proc = pfind(pvd->pvd_pid)) == NULL)
- PFS_RETURN (EIO);
+ if (proc != NULL) {
_PHOLD(proc);
PROC_UNLOCK(proc);
}
@@ -554,7 +551,7 @@ static int
pfs_iterate(struct thread *td, pid_t pid, struct pfs_node *pd,
struct pfs_node **pn, struct proc **p)
{
- sx_assert(&allproc_lock, SX_LOCKED);
+ sx_assert(&allproc_lock, SX_SLOCKED);
again:
if (*pn == NULL) {
/* first node */
@@ -577,7 +574,7 @@ pfs_iterate(struct thread *td, pid_t pid, struct pfs_node *pd,
if ((*pn) == NULL)
return (-1);
- if (!pfs_visible(td, *pn, *p ? (*p)->p_pid : pid))
+ if (!pfs_visible(td, *pn, *p ? (*p)->p_pid : pid, NULL))
goto again;
return (0);
@@ -609,7 +606,7 @@ pfs_readdir(struct vop_readdir_args *va)
uio = va->a_uio;
/* check if the directory is visible to the caller */
- if (!pfs_visible(curthread, pd, pid))
+ if (!pfs_visible(curthread, pd, pid, NULL))
PFS_RETURN (ENOENT);
/* only allow reading entire entries */
@@ -764,7 +761,7 @@ pfs_write(struct vop_write_args *va)
struct pfs_vdata *pvd = (struct pfs_vdata *)vn->v_data;
struct pfs_node *pn = pvd->pvd_pn;
struct uio *uio = va->a_uio;
- struct proc *proc = NULL;
+ struct proc *proc;
struct sbuf sb;
int error;
@@ -783,13 +780,10 @@ pfs_write(struct vop_write_args *va)
* This is necessary because either process' privileges may
* have changed since the open() call.
*/
- if (!pfs_visible(curthread, pn, pvd->pvd_pid))
+ if (!pfs_visible(curthread, pn, pvd->pvd_pid, &proc))
PFS_RETURN (EIO);
- /* XXX duplicates bits of pfs_visible() */
- if (pvd->pvd_pid != NO_PID) {
- if ((proc = pfind(pvd->pvd_pid)) == NULL)
- PFS_RETURN (EIO);
+ if (proc != NULL) {
_PHOLD(proc);
PROC_UNLOCK(proc);
}
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