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pseudofs: fix a LOR pfs_node vs pidhash (sleepable after non-sleepable)

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Sponsored by:	The FreeBSD Foundation
This commit is contained in:
Mateusz Guzik 2019-09-03 12:54:51 +00:00
parent 50f14c4f68
commit f5791174df
1 changed files with 31 additions and 3 deletions
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34
sys/fs/pseudofs/pseudofs_vnops.c
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@ -132,6 +132,24 @@ pfs_visible(struct thread *td, struct pfs_node *pn, pid_t pid,
PFS_RETURN (0);
}
static int
pfs_lookup_proc(pid_t pid, struct proc **p)
{
struct proc *proc;
proc = pfind(pid);
if (proc == NULL)
return (0);
if ((proc->p_flag & P_WEXIT) != 0) {
PROC_UNLOCK(proc);
return (0);
}
_PHOLD(proc);
PROC_UNLOCK(proc);
*p = proc;
return (1);
}
/*
* Verify permissions
*/
@ -791,11 +809,17 @@ pfs_readdir(struct vop_readdir_args *va)
if (resid == 0)
PFS_RETURN (0);
if (!pfs_lookup_proc(pid, &proc))
PFS_RETURN (ENOENT);
sx_slock(&allproc_lock);
pfs_lock(pd);
PROC_LOCK(proc);
/* check if the directory is visible to the caller */
if (!pfs_visible(curthread, pd, pid, &proc)) {
if (!pfs_visible_proc(curthread, pd, proc)) {
_PRELE(proc);
PROC_UNLOCK(proc);
sx_sunlock(&allproc_lock);
pfs_unlock(pd);
PFS_RETURN (ENOENT);
@ -807,8 +831,10 @@ pfs_readdir(struct vop_readdir_args *va)
for (pn = NULL, p = NULL; offset > 0; offset -= PFS_DELEN) {
if (pfs_iterate(curthread, proc, pd, &pn, &p) == -1) {
/* nothing left... */
if (proc != NULL)
if (proc != NULL) {
_PRELE(proc);
PROC_UNLOCK(proc);
}
pfs_unlock(pd);
sx_sunlock(&allproc_lock);
PFS_RETURN (0);
@ -859,8 +885,10 @@ pfs_readdir(struct vop_readdir_args *va)
offset += PFS_DELEN;
resid -= PFS_DELEN;
}
if (proc != NULL)
if (proc != NULL) {
_PRELE(proc);
PROC_UNLOCK(proc);
}
pfs_unlock(pd);
sx_sunlock(&allproc_lock);
i = 0;