Bug#245580: busybox-cvs: lsmod lacks 2.6 support

[Colin Watson <cjwatson@debian.org>]

Package: busybox-cvs
Version: 20040415-3
Severity: wishlist
Tags: d-i patch

On 2.6 systems, busybox lsmod just says "lsmod: QM_MODULES: Function not
implemented". This is because the query_module syscall has been removed
from 2.6; you're apparently supposed to parse /proc/module instead, and
this is what module-init-tools lsmod does.

Here's a fairly straightforward port of the module-init-tools code to
busybox. If this is not accepted for some reason, then just printing out
the contents of /proc/modules would be an improvement over the current
situation. However, I believe this patch is better because it presents a
more consistent (even if not quite identical) output format.

This adds less than half a KB to the busybox binary on powerpc.

diff -u busybox-cvs-20040415/debian/changelog busybox-cvs-20040415/debian/changelog
--- busybox-cvs-20040415/debian/changelog
+++ busybox-cvs-20040415/debian/changelog
@@ -1,3 +1,10 @@
+busybox-cvs (20040415-3.1) UNRELEASED; urgency=low
+
+  * modutils/lsmod.c:
+    - Add 2.6 support, largely borrowed from module-init-tools.
+
+ -- Colin Watson <cjwatson@debian.org>  Thu, 22 Apr 2004 10:26:19 +0100
+
 busybox-cvs (20040415-3) unstable; urgency=low
 
   * modutils:
diff -u busybox-cvs-20040415/modutils/lsmod.c busybox-cvs-20040415/modutils/lsmod.c
--- busybox-cvs-20040415/modutils/lsmod.c
+++ busybox-cvs-20040415/modutils/lsmod.c
@@ -8,6 +8,10 @@
  * Nicolas Ferre <nicolas.ferre@alcove.fr> to support pre 2.1 kernels
  * (which lack the query_module() interface).
  *
+ * Modified by Colin Watson <cjwatson@debian.org> based on lsmod from
+ * module-init-tools (Copyright (C) 2002 Rusty Russell, IBM Corporation)
+ * to support 2.6 kernels.
+ *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
  * the Free Software Foundation; either version 2 of the License, or
@@ -38,6 +42,7 @@
 #include <sys/file.h>
 #include "busybox.h"
 
+#include "modutils.h"
 #include "obj/module.h"
 
 #ifdef CONFIG_FEATURE_CHECK_TAINTED_MODULE
@@ -122,11 +127,54 @@
         return( 0);
 }
 
+#ifdef CONFIG_FEATURE_2_6_MODULES
+static inline int query_2_6_modules(void)
+{
+        char line[4096];
+        FILE *file;
+
+        if ((file = fopen("/proc/modules", "r")) == NULL)
+                bb_perror_msg_and_die("Can't read /proc/modules");
+        while (fgets(line, sizeof(line), file)) {
+                char *mn, *size, *usecount, *deps;
+                mn = strtok(line, " \t");
+                size = strtok(NULL, " \t");
+                printf("%-20s%8s", mn, size);
+                usecount = strtok(NULL, " \t");
+                /* NULL if no module unloading support. */
+                if (usecount) {
+                        deps = strtok(NULL, "\n");
+                        if (!deps)
+                                deps = "";
+                        /* New-style has commas, or -.  If so,
+                         * truncate (other fields might follow). */
+                        else if (strchr(deps, ',')) {
+                                deps = strtok(deps, " \t");
+                                /* Strip trailing comma. */
+                                if (deps[strlen(deps) - 1] == ',')
+                                        deps[strlen(deps) - 1] = '\0';
+                        } else if (deps[0] == '-' &&
+                                   (deps[1] == '\0' || isspace(deps[1])))
+                                deps = "";
+                        printf("%4s %s", usecount, deps);
+                }
+                putchar('\n');
+        }
+        fclose(file);
+        return 0;
+}
+#endif
+
 extern int lsmod_main(int argc, char **argv)
 {
 	printf("Module                  Size  Used by");
 	check_tainted();
 
+#ifdef CONFIG_FEATURE_2_6_MODULES
+        if (get_kernel_revision() > MODUTILS_MINIMAL_VERSION_2_6)
+                return query_2_6_modules();
+#endif
+
 #ifdef CONFIG_FEATURE_QUERY_MODULE_INTERFACE
         if (getuid() != 0)
         {

Thanks,

-- 
Colin Watson                                  [cjwatson@flatline.org.uk]