lcdproc client: Fix core dumps on FreeBSD if started as non-root.

BUGS

@@ -7,6 +7,9 @@ V0.5dev:
     a non full block from the vBar. Affected drivers: IOWarrior, CwLinux
   - On Solaris the mtc_s16209x driver fails to compile. Configure LCDproc to
     exclude this driver.
+  - The lcdproc client currently ignores errors from the machine dependent
+    functions. This may result in strange behaviour of the screens or core
+    dumps.
 
 
 Bugs in previous versions (not checked if the still exist):

ChangeLog

@@ -16,6 +16,7 @@ v0.5dev (ongoing development)
  + hd44780: Fix vBars and block icon not working correctly on the same screen
  * Build system: Link LCDd itself with pthread library if available
  * lcdproc client: Unbreak build on OpenBSD non-i386 (E. Barrett)
+ * lcdproc client: Fix core dumps on FreeBSD if started as non-root
 
 v0.5.5
  + sed1330 driver: Add support for HG25504 (L. Lagendijk)

clients/lcdproc/machine_FreeBSD.c

@@ -106,7 +106,10 @@ machine_init(void)
 int
 machine_close(void)
 {
-	kvm_close(kvmd);
+	if (kvmd != NULL) {
+		kvm_close(kvmd);
+		kvmd = NULL;
+	}
 	return (TRUE);
 }
 
@@ -311,10 +314,12 @@ machine_get_procs(LinkedList * procs)
 	int nproc, i;
 	procinfo_type *p;
 
+	if (kvmd == NULL)
+		return (FALSE);
+
 	kprocs = kvm_getprocs(kvmd, KERN_PROC_ALL, 0, &nproc);
 	if (kprocs == NULL) {
 		perror("kvm_getprocs");
-		kvm_close(kvmd);
 		return (FALSE);
 	}
 
@@ -322,7 +327,6 @@ machine_get_procs(LinkedList * procs)
 		p = malloc(sizeof(procinfo_type));
 		if (!p) {
 			perror("mem_top_malloc");
-			kvm_close(kvmd);
 			return (FALSE);
 		}
 #if (__FreeBSD_version > 500000)
@@ -355,6 +359,9 @@ machine_get_smpload(load_type * result, int *numcpus)
 #ifdef HAVE_SYS_PCPU_H
 	static load_type last_load[MAX_CPUS];
 	struct pcpu *pcpudata;
+
+	if (kvmd == NULL)
+		return (FALSE);
 #endif
 
 	if (numcpus == NULL)
@@ -439,20 +446,23 @@ machine_get_uptime(double *up, double *idle)
 	return (TRUE);
 }
 
+/**
+ * Reads info about swap space from system and returns it in parameters passed.
+ * \param retavail  Total available swap space
+ * \param retfree   Free swap space
+ * \return  -1 on error, otherwise number of swap areas (typically 0 for total)
+ */
 static int
 swapmode(int *retavail, int *retfree)
 {
 	int n;
 	struct kvm_swap swapary[1];
-	kvm_t *kvmd;
 
 	*retavail = 0;
 	*retfree = 0;
 
-	if ((kvmd = kvm_open(NULL, NULL, NULL, O_RDONLY, "kvm_open")) == NULL) {
-		perror("read kvm");
-		return (-1);
-	}
+	if (kvmd == NULL)
+		return -1;
 
 	n = kvm_getswapinfo(kvmd, swapary, 1, 0);
 	if (n < 0 || swapary[0].ksw_total == 0) {
@@ -463,8 +473,6 @@ swapmode(int *retavail, int *retfree)
 		*retfree = pagetok(swapary[0].ksw_total - swapary[0].ksw_used);
 	}
 
-	kvm_close(kvmd);
-
 	return (n);
 }
 

clients/lcdproc/mem.c

@@ -288,6 +288,7 @@ mem_top_screen(int rep, int display, int *flags_ptr)
 		sock_send_string(sock, "widget_set S 1 1 1 Checking...\n");
 	}
 
+	/* Create a new process list */
 	procs = LL_new();
 	if (procs == NULL) {
 		fprintf(stderr, "mem_top_screen: Error allocating list\n");
@@ -295,6 +296,10 @@ mem_top_screen(int rep, int display, int *flags_ptr)
 	}
 
 	machine_get_procs(procs);
+	/*
+	 * Ignore if machine_get_procs returns an errror. The list will be
+	 * empty then and all process info will be shown empty, too.
+	 */
 
 	/* Now, print some info... */
 	LL_Rewind(procs);
@@ -325,7 +330,7 @@ mem_top_screen(int rep, int display, int *flags_ptr)
 		LL_Next(procs);
 	}
 
-	/* Now clean it all up... */
+	/* Delete the process list */
 	LL_Rewind(procs);
 	do {
 		procinfo_type *p = (procinfo_type *) LL_Get(procs);