From: Sascha Wildner <saw@online.de>
Date: Tue, 21 Aug 2012 18:57:19 +0000 (+0200)
Subject: kernel/linprocfs: Fix accessing files in /proc (such as /proc/meminfo).
X-Git-Tag: v3.2.0~303
X-Git-Url: http://gitweb.dragonflybsd.org/dragonfly.git/commitdiff_plain/96a686f903f23302471b538c669c9b0cf3eff5e9

kernel/linprocfs: Fix accessing files in /proc (such as /proc/meminfo).

It is the same fix that was applied to procfs with 198c0ff2.
---

diff --git a/sys/emulation/linux/i386/linprocfs/linprocfs.h b/sys/emulation/linux/i386/linprocfs/linprocfs.h
index 488c5c2..aba5d72 100644
--- a/sys/emulation/linux/i386/linprocfs/linprocfs.h
+++ b/sys/emulation/linux/i386/linprocfs/linprocfs.h
@@ -136,6 +136,7 @@ int linprocfs_freevp (struct vnode *);
 int linprocfs_allocvp (struct mount *, struct vnode **, long, pfstype);
 int linprocfs_sstep (struct proc *);
 void linprocfs_fix_sstep (struct proc *);
+struct proc *linprocfs_pfind(pid_t pfs_pid);
 #if 0
 int linprocfs_read_regs (struct proc *, struct reg *);
 int linprocfs_write_regs (struct proc *, struct reg *);
diff --git a/sys/emulation/linux/i386/linprocfs/linprocfs_subr.c b/sys/emulation/linux/i386/linprocfs/linprocfs_subr.c
index 8dc4f8f..d2db8e3 100644
--- a/sys/emulation/linux/i386/linprocfs/linprocfs_subr.c
+++ b/sys/emulation/linux/i386/linprocfs/linprocfs_subr.c
@@ -251,6 +251,26 @@ linprocfs_freevp(struct vnode *vp)
 	return (0);
 }
 
+/*
+ * Try to find the calling pid. Note that pfind()
+ * now references the proc structure to be returned
+ * and needs to be released later with PRELE().
+ */
+struct proc *
+linprocfs_pfind(pid_t pfs_pid)
+{
+	struct proc *p = NULL;
+
+	if (pfs_pid == 0) {
+		p = &proc0;
+		PHOLD(p);
+	} else {
+		p = pfind(pfs_pid);
+	}
+
+	return p;
+}
+
 int
 linprocfs_rw(struct vop_read_args *ap)
 {
@@ -266,12 +286,14 @@ linprocfs_rw(struct vop_read_args *ap)
 	curp = td->td_proc;
 	KKASSERT(curp);
 
-	p = pfind(pfs->pfs_pid);
-	if (p == NULL)
-		return (EINVAL);
+	p = linprocfs_pfind(pfs->pfs_pid);
+	if (p == NULL) {
+		rtval = EINVAL;
+		goto out;
+	}
 	if (p->p_pid == 1 && securelevel > 0 && uio->uio_rw == UIO_WRITE) {
-		PRELE(p);
-		return (EACCES);
+		rtval = EACCES;
+		goto out;
 	}
 	lp = FIRST_LWP_IN_PROC(p);
 	LWPHOLD(lp);
@@ -340,12 +362,14 @@ linprocfs_rw(struct vop_read_args *ap)
 		break;
 	}
 	LWPRELE(lp);
-	PRELE(p);
 
 	lwkt_gettoken(&pfs_token);
 	pfs->pfs_lockowner = NULL;
 	wakeup(&pfs->pfs_lockowner);
 	lwkt_reltoken(&pfs_token);
+out:
+	if (p)
+		PRELE(p);
 
 	return rtval;
 }
diff --git a/sys/emulation/linux/i386/linprocfs/linprocfs_vnops.c b/sys/emulation/linux/i386/linprocfs/linprocfs_vnops.c
index 77d1f3a..7ea3061 100644
--- a/sys/emulation/linux/i386/linprocfs/linprocfs_vnops.c
+++ b/sys/emulation/linux/i386/linprocfs/linprocfs_vnops.c
@@ -177,7 +177,7 @@ linprocfs_open(struct vop_open_args *ap)
 	struct pfsnode *pfs = VTOPFS(ap->a_vp);
 	struct proc *p2;
 
-	p2 = PFIND(pfs->pfs_pid);
+	p2 = linprocfs_pfind(pfs->pfs_pid);
 	if (p2 == NULL)
 		return (ENOENT);
 	if (pfs->pfs_pid && !PRISON_CHECK(ap->a_cred, p2->p_ucred))
@@ -231,7 +231,7 @@ linprocfs_close(struct vop_close_args *ap)
 		 */
 		p = NULL;
 		if ((ap->a_vp->v_opencount < 2)
-		    && (p = pfind(pfs->pfs_pid))
+		    && (p = linprocfs_pfind(pfs->pfs_pid))
 		    && !(p->p_pfsflags & PF_LINGER)) {
 			p->p_stops = 0;
 			p->p_step = 0;
@@ -260,7 +260,7 @@ linprocfs_ioctl(struct vop_ioctl_args *ap)
 	struct procfs_status *psp;
 	unsigned char flags;
 
-	procp = pfind(pfs->pfs_pid);
+	procp = linprocfs_pfind(pfs->pfs_pid);
 	if (procp == NULL) {
 		return ENOTTY;
 	}
@@ -465,7 +465,7 @@ linprocfs_getattr(struct vop_getattr_args *ap)
 		break;
 
 	default:
-		procp = PFIND(pfs->pfs_pid);
+		procp = linprocfs_pfind(pfs->pfs_pid);
 		if (procp == NULL || procp->p_ucred == NULL)
 			return (ENOENT);
 	}
@@ -844,7 +844,7 @@ linprocfs_lookup(struct vop_old_lookup_args *ap)
 		if (pid == NO_PID)
 			break;
 
-		p = PFIND(pid);
+		p = linprocfs_pfind(pid);
 		if (p == NULL)
 			break;
 
@@ -864,7 +864,7 @@ linprocfs_lookup(struct vop_old_lookup_args *ap)
 			goto out;
 		}
 
-		p = PFIND(pfs->pfs_pid);
+		p = linprocfs_pfind(pfs->pfs_pid);
 		if (p == NULL)
 			break;
 
@@ -991,7 +991,7 @@ linprocfs_readdir_proc(struct vop_readdir_args *ap)
 	struct uio *uio = ap->a_uio;
 
 	pfs = VTOPFS(ap->a_vp);
-	p = PFIND(pfs->pfs_pid);
+	p = linprocfs_pfind(pfs->pfs_pid);
 	if (p == NULL)
 		return(0);
 	if (!PRISON_CHECK(ap->a_cred, p->p_ucred))
@@ -1517,7 +1517,7 @@ linprocfs_readlink(struct vop_readlink_args *ap)
 	 * from under us...
 	 */
 	case Pexe:
-		procp = PFIND(pfs->pfs_pid);
+		procp = linprocfs_pfind(pfs->pfs_pid);
 		if (procp == NULL || procp->p_ucred == NULL) {
 			kprintf("linprocfs_readlink: pid %d disappeared\n",
 			    pfs->pfs_pid);
@@ -1532,7 +1532,7 @@ linprocfs_readlink(struct vop_readlink_args *ap)
 		kfree(freepath, M_TEMP);
 		return (error);
 	case Pcwd:
-		procp = PFIND(pfs->pfs_pid);
+		procp = linprocfs_pfind(pfs->pfs_pid);
 		if (procp == NULL || procp->p_ucred == NULL) {
 			kprintf("linprocfs_readlink: pid %d disappeared\n",
 			    pfs->pfs_pid);
@@ -1547,7 +1547,7 @@ linprocfs_readlink(struct vop_readlink_args *ap)
 		kfree(freepath, M_TEMP);
 		return (error);
 	case Pprocroot:
-		procp = PFIND(pfs->pfs_pid);
+		procp = linprocfs_pfind(pfs->pfs_pid);
 		if (procp == NULL || procp->p_ucred == NULL) {
 			kprintf("linprocfs_readlink: pid %d disappeared\n",
 			    pfs->pfs_pid);
@@ -1563,7 +1563,7 @@ linprocfs_readlink(struct vop_readlink_args *ap)
 		kfree(freepath, M_TEMP);
 		return (error);
 	case Pfd:
-		procp = PFIND(pfs->pfs_pid);
+		procp = linprocfs_pfind(pfs->pfs_pid);
 		if (procp == NULL || procp->p_ucred == NULL) {
 			kprintf("linprocfs_readlink: pid %d disappeared\n",
 			    pfs->pfs_pid);