processes plugin: Improve the error handling.

The fork-rate function now returns ULONG_MAX upon error. The error detection
when using strtoul has been improved (overflow is not the only possible error).

diff --git a/src/processes.c b/src/processes.c
index 3623f73f9683c68e90af4e03404518588918be80..c96e9110b95a9b804001490bffc7a8dda0581a05 100644 (file)
--- a/src/processes.c
+++ b/src/processes.c
@@ -846,29 +846,36 @@ static unsigned long read_fork_rate ()
        char buf[1024];
        unsigned long result = 0;
        int numfields;
-       char *fields[2];
+       char *fields[3];
 
        proc_stat = fopen("/proc/stat", "r");
        if (proc_stat == NULL) {
                char errbuf[1024];
                ERROR ("processes plugin: fopen (/proc/stat) failed: %s",
                                sstrerror (errno, errbuf, sizeof (errbuf)));
-               return 0;
+               return ULONG_MAX;
        }
 
        while (fgets (buf, sizeof(buf), proc_stat) != NULL)
        {
-               if (strncmp (buf, "processes", 9))
-                       continue;
-               numfields = strsplit(buf, fields, 2);
+               char *endptr;
+
+               numfields = strsplit(buf, fields, STATIC_ARRAY_SIZE (fields));
                if (numfields != 2) {
-                       ERROR ("processes plugin: processes in /proc/stat contain more than 2 fields.");
+                       ERROR ("processes plugin: processes in /proc/stat "
+                                       "contains more than 2 fields.");
                        break;
                }
+               if (strcmp ("processes", fields[0]) != 0)
+                       continue;
 
-               result = strtoul(fields[1], NULL, 10);
-               if (errno == ERANGE && result == ULONG_MAX) {
-                       ERROR ("processes plugin: processes value in /proc/stat overflows.");
+               errno = 0;
+               endptr = NULL;
+               result = strtoul(fields[1], &endptr, 10);
+               if ((endptr == fields[1]) || (errno != 0)) {
+                       ERROR ("processes plugin: Cannot parse fork rate: %s",
+                                       fields[1]);
+                       result = ULONG_MAX;
                        break;
                }
 
@@ -885,7 +892,7 @@ static void ps_submit_fork_rate (unsigned long value)
        value_t values[1];
        value_list_t vl = VALUE_LIST_INIT;
 
-       values[0].derive = value;
+       values[0].derive = (derive_t) value;
 
        vl.values = values;
        vl.values_len = 1;
@@ -1297,7 +1304,8 @@ static int ps_read (void)
                ps_submit_proc_list (ps_ptr);
 
        fork_rate = read_fork_rate();
-       ps_submit_fork_rate(fork_rate);
+       if (fork_rate != ULONG_MAX)
+               ps_submit_fork_rate(fork_rate);
 /* #endif KERNEL_LINUX */
 
 #elif HAVE_LIBKVM_GETPROCS && HAVE_STRUCT_KINFO_PROC_FREEBSD