Date: Tue, 3 Sep 2019 12:54:51 +0000 (UTC) From: Mateusz Guzik <mjg@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r351741 - head/sys/fs/pseudofs Message-ID: <201909031254.x83Csp8c012433@repo.freebsd.org>
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Author: mjg Date: Tue Sep 3 12:54:51 2019 New Revision: 351741 URL: https://svnweb.freebsd.org/changeset/base/351741 Log: pseudofs: fix a LOR pfs_node vs pidhash (sleepable after non-sleepable) Sponsored by: The FreeBSD Foundation Modified: head/sys/fs/pseudofs/pseudofs_vnops.c Modified: head/sys/fs/pseudofs/pseudofs_vnops.c ============================================================================== --- head/sys/fs/pseudofs/pseudofs_vnops.c Tue Sep 3 12:40:58 2019 (r351740) +++ head/sys/fs/pseudofs/pseudofs_vnops.c Tue Sep 3 12:54:51 2019 (r351741) @@ -132,6 +132,24 @@ pfs_visible(struct thread *td, struct pfs_node *pn, pi 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;
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