Add per-process osrel node to the procfs, to allow read and set p_osrel

value for the process.

Approved by:	des (procfs maintainer)
MFC after:	3 weeks

sys/conf/files

@@ -1792,6 +1792,7 @@ fs/procfs/procfs_ioctl.c	optional procfs
 fs/procfs/procfs_map.c		optional procfs
 fs/procfs/procfs_mem.c		optional procfs
 fs/procfs/procfs_note.c		optional procfs
+fs/procfs/procfs_osrel.c	optional procfs
 fs/procfs/procfs_regs.c		optional procfs
 fs/procfs/procfs_rlimit.c	optional procfs
 fs/procfs/procfs_status.c	optional procfs

sys/fs/procfs/procfs.c

@@ -108,7 +108,8 @@ procfs_attr(PFS_ATTR_ARGS)
 	else if (strcmp(pn->pn_name, "mem") == 0 ||
 	    strcmp(pn->pn_name, "regs") == 0 ||
 	    strcmp(pn->pn_name, "dbregs") == 0 ||
-	    strcmp(pn->pn_name, "fpregs") == 0)
+	    strcmp(pn->pn_name, "fpregs") == 0 ||
+	    strcmp(pn->pn_name, "osrel") == 0)
 		vap->va_mode = 0600;
 
 	if (p != NULL) {
@@ -186,6 +187,8 @@ procfs_init(PFS_INIT_ARGS)
 	    NULL, NULL, NULL, PFS_RD);
 	pfs_create_file(dir, "status", procfs_doprocstatus,
 	    NULL, NULL, NULL, PFS_RD);
+	pfs_create_file(dir, "osrel", procfs_doosrel,
+	    procfs_attr, procfs_candebug, NULL, PFS_RDWR);
 
 	pfs_create_link(dir, "file", procfs_doprocfile,
 	    NULL, procfs_notsystem, NULL, 0);

sys/fs/procfs/procfs.h

@@ -39,6 +39,7 @@
 #ifdef _KERNEL
 
 int	 procfs_docurproc(PFS_FILL_ARGS);
+int	 procfs_doosrel(PFS_FILL_ARGS);
 int	 procfs_doproccmdline(PFS_FILL_ARGS);
 int	 procfs_doprocctl(PFS_FILL_ARGS);
 int	 procfs_doprocdbregs(PFS_FILL_ARGS);

sys/fs/procfs/procfs_osrel.c

@@ -0,0 +1,68 @@
+/*-
+ * Copyright (c) 2009 Konstantin Belousov
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 4. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <sys/param.h>
+#include <sys/proc.h>
+#include <sys/sbuf.h>
+#include <sys/uio.h>
+
+#include <fs/pseudofs/pseudofs.h>
+#include <fs/procfs/procfs.h>
+
+int
+procfs_doosrel(PFS_FILL_ARGS)
+{
+	const char *pp;
+	int ov, osrel, i;
+
+	if (uio == NULL)
+		return (EOPNOTSUPP);
+	if (uio->uio_rw == UIO_READ) {
+		sbuf_printf(sb, "%d\n", p->p_osrel);
+	} else {
+		sbuf_trim(sb);
+		sbuf_finish(sb);
+		pp = sbuf_data(sb);
+		osrel = 0;
+		i = sbuf_len(sb);
+		while (i--) {
+			if (*pp < '0' || *pp > '9')
+				return (EINVAL);
+			ov = osrel * 10 + *pp++ - '0';
+			if (ov < osrel)
+				return (EINVAL);
+			osrel = ov;
+		}
+		p->p_osrel = osrel;
+	}
+	return (0);
+}

sys/modules/procfs/Makefile

@@ -13,6 +13,7 @@ SRCS+=		procfs_ioctl.c
 SRCS+=		procfs_map.c
 SRCS+=		procfs_mem.c
 SRCS+=		procfs_note.c
+SRCS+=		procfs_osrel.c
 SRCS+=		procfs_regs.c
 SRCS+=		procfs_rlimit.c
 SRCS+=		procfs_status.c