Lock access to proc members.

Glanced over by:	marcel

sys/compat/linux/linux_file.c

@@ -124,14 +124,17 @@ linux_open(struct proc *p, struct linux_open_args *args)
     bsd_open_args.mode = args->mode;
 
     error = open(p, &bsd_open_args);
+    PROC_LOCK(p);
     if (!error && !(bsd_open_args.flags & O_NOCTTY) && 
 	SESS_LEADER(p) && !(p->p_flag & P_CONTROLT)) {
 	struct filedesc *fdp = p->p_fd;
 	struct file *fp = fdp->fd_ofiles[p->p_retval[0]];
 
+	PROC_UNLOCK(p);
 	if (fp->f_type == DTYPE_VNODE)
 	    fo_ioctl(fp, TIOCSCTTY, (caddr_t) 0, p);
-    }
+    } else
+	PROC_UNLOCK(p);
 #ifdef DEBUG
     printf("Linux-emul(%d): open returns error %d\n", 
 	   p->p_pid, error);
@@ -402,6 +405,7 @@ linux_getdents(struct proc *p, struct linux_getdents_args *args)
     int buflen, error, eofflag, nbytes, justone;
     u_long *cookies = NULL, *cookiep;
     int ncookies;
+    struct ucred *uc;
 
 #ifdef DEBUG
     printf("Linux-emul(%d): getdents(%d, *, %d)\n",
@@ -419,7 +423,13 @@ linux_getdents(struct proc *p, struct linux_getdents_args *args)
     if (vp->v_type != VDIR)
 	return (EINVAL);
 
-    if ((error = VOP_GETATTR(vp, &va, p->p_ucred, p))) {
+    PROC_LOCK(p);
+    uc = p->p_ucred;
+    crhold(uc);
+    PROC_UNLOCK(p);
+    error = VOP_GETATTR(vp, &va, uc, p);
+    crfree(uc);
+    if (error) {
 	return error;
     }
 

sys/compat/linux/linux_misc.c

@@ -185,6 +185,7 @@ linux_uselib(struct proc *p, struct linux_uselib_args *args)
     struct vnode *vp;
     struct exec *a_out;
     struct vattr attr;
+    struct ucred *uc;
     vm_offset_t vmaddr;
     unsigned long file_offset;
     vm_offset_t buffer;
@@ -236,14 +237,21 @@ linux_uselib(struct proc *p, struct linux_uselib_args *args)
     /*
      * Executable?
      */
-    error = VOP_GETATTR(vp, &attr, p->p_ucred, p);
+    PROC_LOCK(p);
-    if (error)
+    uc = p->p_ucred;
+    crhold(uc);
+    PROC_UNLOCK(p);
+    error = VOP_GETATTR(vp, &attr, uc, p);
+    if (error) {
+	crfree(uc);
 	goto cleanup;
+    }
 
     if ((vp->v_mount->mnt_flag & MNT_NOEXEC) ||
 	((attr.va_mode & 0111) == 0) ||
 	(attr.va_type != VREG)) {
 	    error = ENOEXEC;
+	    crfree(uc);
 	    goto cleanup;
     }
 
@@ -252,17 +260,21 @@ linux_uselib(struct proc *p, struct linux_uselib_args *args)
      */
     if (attr.va_size == 0) {
 	error = ENOEXEC;
+	crfree(uc);
 	goto cleanup;
     }
 
     /*
      * Can we access it?
      */
-    error = VOP_ACCESS(vp, VEXEC, p->p_ucred, p);
+    error = VOP_ACCESS(vp, VEXEC, uc, p);
-    if (error)
+    if (error) {
+	crfree(uc);
 	goto cleanup;
+    }
 
-    error = VOP_OPEN(vp, FREAD, p->p_ucred, p);
+    error = VOP_OPEN(vp, FREAD, uc, p);
+    crfree(uc);
     if (error)
 	goto cleanup;
 
@@ -321,6 +333,9 @@ linux_uselib(struct proc *p, struct linux_uselib_args *args)
 	goto cleanup;
     }
 
+    /* To protect p->p_rlimit in the if condition. */
+    mtx_assert(&Giant, MA_OWNED);
+
     /*
      * text/data/bss must not exceed limits
      * XXX: this is not complete. it should check current usage PLUS

sys/compat/linux/linux_signal.c

@@ -231,20 +231,19 @@ static int
 linux_do_sigprocmask(struct proc *p, int how, linux_sigset_t *new,
 		     linux_sigset_t *old)
 {
-	int error, s;
+	int error;
 	sigset_t mask;
 
 	error = 0;
 	p->p_retval[0] = 0;
 
+	PROC_LOCK(p);
 	if (old != NULL)
 		bsd_to_linux_sigset(&p->p_sigmask, old);
 
 	if (new != NULL) {
 		linux_to_bsd_sigset(new, &mask);
 
-		s = splhigh();
-
 		switch (how) {
 		case LINUX_SIG_BLOCK:
 			SIGSETOR(p->p_sigmask, mask);
@@ -261,9 +260,8 @@ linux_do_sigprocmask(struct proc *p, int how, linux_sigset_t *new,
 			error = EINVAL;
 			break;
 		}
-
-		splx(s);
 	}
+	PROC_UNLOCK(p);
 
 	return (error);
 }
@@ -343,7 +341,9 @@ linux_siggetmask(struct proc *p, struct linux_siggetmask_args *args)
 	printf("Linux-emul(%d): siggetmask()\n", p->p_pid);
 #endif
 
+	PROC_LOCK(p);
 	bsd_to_linux_sigset(&p->p_sigmask, &mask);
+	PROC_UNLOCK(p);
 	p->p_retval[0] = mask.__bits[0];
 	return (0);
 }
@@ -353,22 +353,21 @@ linux_sigsetmask(struct proc *p, struct linux_sigsetmask_args *args)
 {
 	linux_sigset_t lset;
 	sigset_t bset;
-	int s;
 
 #ifdef DEBUG
 	printf("Linux-emul(%ld): sigsetmask(%08lx)\n",
 	       (long)p->p_pid, (unsigned long)args->mask);
 #endif
 
+	PROC_LOCK(p);
 	bsd_to_linux_sigset(&p->p_sigmask, &lset);
 	p->p_retval[0] = lset.__bits[0];
 	LINUX_SIGEMPTYSET(lset);
 	lset.__bits[0] = args->mask;
 	linux_to_bsd_sigset(&lset, &bset);
-	s = splhigh();
 	p->p_sigmask = bset;
 	SIG_CANTMASK(p->p_sigmask);
-	splx(s);
+	PROC_UNLOCK(p);
 	return (0);
 }
 
@@ -383,9 +382,11 @@ linux_sigpending(struct proc *p, struct linux_sigpending_args *args)
 	printf("Linux-emul(%d): sigpending(*)\n", p->p_pid);
 #endif
 
+	PROC_LOCK(p);
 	bset = p->p_siglist;
 	SIGSETAND(bset, p->p_sigmask);
 	bsd_to_linux_sigset(&bset, &lset);
+	PROC_UNLOCK(p);
 	mask = lset.__bits[0];
 	return (copyout(&mask, args->mask, sizeof(mask)));
 }

sys/compat/linux/linux_util.c

@@ -62,6 +62,7 @@ linux_emul_find(p, sgp, prefix, path, pbuf, cflag)
 	struct nameidata	 ndroot;
 	struct vattr		 vat;
 	struct vattr		 vatroot;
+	struct ucred		*uc;
 	int			 error;
 	char			*ptr, *buf, *cp;
 	size_t			 sz, len;
@@ -140,12 +141,18 @@ linux_emul_find(p, sgp, prefix, path, pbuf, cflag)
 			return error;
 		}
 
-		if ((error = VOP_GETATTR(nd.ni_vp, &vat, p->p_ucred, p)) != 0) {
+		PROC_LOCK(p);
+		uc = p->p_ucred;
+		crhold(uc);
+		PROC_UNLOCK(p);
+		if ((error = VOP_GETATTR(nd.ni_vp, &vat, uc, p)) != 0) {
+			crfree(uc);
 			goto bad;
 		}
 
-		if ((error = VOP_GETATTR(ndroot.ni_vp, &vatroot, p->p_ucred, p))
+		error = VOP_GETATTR(ndroot.ni_vp, &vatroot, uc, p);
-		    != 0) {
+		crfree(uc);
+		if (error != 0) {
 			goto bad;
 		}