svn commit: r335516 - head/sys/compat/linprocfs

[Chuck Tuffli]

Author: chuck
Date: Fri Jun 22 00:02:05 2018
New Revision: 335516
URL: https://svnweb.freebsd.org/changeset/base/335516

Log:
  Fix output of linprocfs stat entry
  
  The Linux /proc/stat entry has grown over time
  
   v2.5.41 <
     user, nice, system, idle
   v2.5.41
     user, nice, system, idle, iowait, irq
   v2.6.11
     user, nice, system, idle, iowait, irq, softirq, steal
   v2.6.24
     user, nice, system, idle, iowait, irq, softirq, steal, guest
   v2.6.32 >
     user, nice, system, idle, iowait, irq, softirq, steal, guest, guest_nice
  
  Some applications (e.g. nodejs) depend on the correct number of entries
  and will abort otherwise.
  
  Fix is to print the correct number of entries based on the value of
  osrelease set either in sysctl or the jail settings. Change is similar
  to approach used by illumos.
  
  Reviewed by: emaste, imp (mentor)
  Approved by: imp (mentor)
  Differential Revision: https://reviews.freebsd.org/D15858

Modified:
  head/sys/compat/linprocfs/linprocfs.c

Modified: head/sys/compat/linprocfs/linprocfs.c
==============================================================================
--- head/sys/compat/linprocfs/linprocfs.c	Fri Jun 22 00:02:03 2018	(r335515)
+++ head/sys/compat/linprocfs/linprocfs.c	Fri Jun 22 00:02:05 2018	(r335516)
@@ -469,9 +469,21 @@ linprocfs_dopartitions(PFS_FILL_ARGS)
 	return (0);
 }
 
-
 /*
  * Filler function for proc/stat
+ *
+ * Output depends on kernel version:
+ *
+ * v2.5.40 <=
+ *   user nice system idle
+ * v2.5.41
+ *   user nice system idle iowait
+ * v2.6.11
+ *   user nice system idle iowait irq softirq steal
+ * v2.6.24
+ *   user nice system idle iowait irq softirq steal guest
+ * v2.6.33 >=
+ *   user nice system idle iowait irq softirq steal guest guest_nice
  */
 static int
 linprocfs_dostat(PFS_FILL_ARGS)
@@ -481,22 +493,54 @@ linprocfs_dostat(PFS_FILL_ARGS)
 	long *cp;
 	struct timeval boottime;
 	int i;
+	char *zero_pad;
+	bool has_intr = true;
 
+	if (linux_kernver(td) >= LINUX_KERNVER(2,6,33)) {
+		zero_pad = " 0 0 0 0\n";
+	} else if (linux_kernver(td) >= LINUX_KERNVER(2,6,24)) {
+		zero_pad = " 0 0 0\n";
+	} else if (linux_kernver(td) >= LINUX_KERNVER(2,6,11)) {
+		zero_pad = " 0 0\n";
+	} else if (linux_kernver(td) >= LINUX_KERNVER(2,5,41)) {
+		has_intr = false;
+		zero_pad = " 0\n";
+	} else {
+		has_intr = false;
+		zero_pad = "\n";
+	}
+
 	read_cpu_time(cp_time);
 	getboottime(&boottime);
-	sbuf_printf(sb, "cpu %ld %ld %ld %ld\n",
+	/* Parameters common to all versions */
+	sbuf_printf(sb, "cpu %lu %lu %lu %lu",
 	    T2J(cp_time[CP_USER]),
 	    T2J(cp_time[CP_NICE]),
-	    T2J(cp_time[CP_SYS] /*+ cp_time[CP_INTR]*/),
+	    T2J(cp_time[CP_SYS]),
 	    T2J(cp_time[CP_IDLE]));
+
+	/* Print interrupt stats if available */
+	if (has_intr) {
+		sbuf_printf(sb, " 0 %lu", T2J(cp_time[CP_INTR]));
+	}
+
+	/* Pad out remaining fields depending on version */
+	sbuf_printf(sb, "%s", zero_pad);
+
 	CPU_FOREACH(i) {
 		pcpu = pcpu_find(i);
 		cp = pcpu->pc_cp_time;
-		sbuf_printf(sb, "cpu%d %ld %ld %ld %ld\n", i,
+		sbuf_printf(sb, "cpu%d %lu %lu %lu %lu", i,
 		    T2J(cp[CP_USER]),
 		    T2J(cp[CP_NICE]),
-		    T2J(cp[CP_SYS] /*+ cp[CP_INTR]*/),
+		    T2J(cp[CP_SYS]),
 		    T2J(cp[CP_IDLE]));
+
+		if (has_intr) {
+			sbuf_printf(sb, " 0 %lu", T2J(cp[CP_INTR]));
+		}
+
+		sbuf_printf(sb, "%s", zero_pad);
 	}
 	sbuf_printf(sb,
 	    "disk 0 0 0 0\n"