[rhel5-branch 3/5] Compute size of modules buffer in loader (#484092)

[David Cantrell <dcantrell redhat com>]

In hardware.c, we build a colon-separated list of module names.  The
buffer storing that string was set to a hard limit of 1024, which isn't
big enough for certain systems.  This patch changes the function to
calculate the length required of the buffer and resize it with
realloc().
---
 loader2/hardware.c |   34 ++++++++++++++++++++++++++++------
 1 files changed, 28 insertions(+), 6 deletions(-)

diff --git a/loader2/hardware.c b/loader2/hardware.c
index 2cea886..7c574eb 100644
--- a/loader2/hardware.c
+++ b/loader2/hardware.c
@@ -247,9 +247,9 @@ int earlyModuleLoad(moduleInfoSet modInfo, moduleList modLoaded,
 
 int busProbe(moduleInfoSet modInfo, moduleList modLoaded, moduleDeps modDeps,
              int justProbe) {
-    int i;
+    int i, len = 0;
     char ** modList;
-    char modules[1024];
+    char *modules = NULL;
     
     /* we always want to try to find out about pcmcia controllers even
      * if using noprobe */
@@ -269,17 +269,39 @@ int busProbe(moduleInfoSet modInfo, moduleList modLoaded, moduleDeps modDeps,
         } else if (modList) {
             int probeVirtioAgain = 0;
 
-            *modules = '\0';
-            
+            /* compute length of colon-separated string */
+            for (i = 0; modList[i]; i++) {
+                if (i) {
+                    len += 1;    /* ':' between each module name */
+                }
+
+                len += strlen(modList[i]);
+            }
+
+            len += 1;            /* '\0' at the end */
+
             for (i = 0; modList[i]; i++) {
-                if (i) strcat(modules, ":");
-                strcat(modules, modList[i]);
+                if (i > 0) {
+                    modules = strncat(modules, ":", 1);
+                }
+
+                if (modules == NULL) {
+                    modules = strdup(modList[i]);
+
+                    if ((modules = realloc(modules, len)) == NULL) {
+                        logMessage(ERROR, "error building modules string");
+                        return 0;
+                    }
+                } else {
+                    modules = strncat(modules, modList[i], strlen(modList[i]));
+                }
 
                 if (!strcmp(modList[i], "virtio_pci"))
                     probeVirtioAgain = 1;
             }
             
             mlLoadModuleSet(modules, modLoaded, modDeps, modInfo);
+            free(modules);
 
             if (probeVirtioAgain)
                 probeVirtio(modInfo, modLoaded, modDeps);
-- 
1.6.2.2