depmod: fix handling of .gz modules

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

3 files changed, 47 insertions, 14 deletions

diff --git a/modutils/depmod.c b/modutils/depmod.c
index 405ba9e2a..5ec2a51dd 100644
--- a/modutils/depmod.c
+++ b/modutils/depmod.c
@@ -40,26 +40,28 @@ enum {
         ARG_r = (1<<6)  /* Compat dummy. Linux Makefile uses it */
 };
 
-static int FAST_FUNC parse_module(const char *fname, struct stat *sb,
-                                  void *data, int UNUSED_PARAM depth)
+static int FAST_FUNC parse_module(const char *fname, struct stat *sb UNUSED_PARAM,
+                                  void *data, int depth UNUSED_PARAM)
 {
+        char modname[MODULE_NAME_LEN];
         module_info **first = (module_info **) data;
         char *image, *ptr;
         module_info *info;
-        size_t len = sb->st_size;
+        /* Arbitrary. Was sb->st_size, but that breaks .gz etc */
+        size_t len = (64*1024*1024 - 4096);
 
         if (strrstr(fname, ".ko") == NULL)
                 return TRUE;
 
         image = xmalloc_open_zipped_read_close(fname, &len);
-        info = xzalloc(sizeof(module_info));
+        info = xzalloc(sizeof(*info));
 
         info->next = *first;
         *first = info;
 
         info->dnext = info->dprev = info;
         info->name = xasprintf("/%s", fname);
-        info->modname = filename2modname(fname, NULL);
+        info->modname = xstrdup(filename2modname(fname, modname));
         for (ptr = image; ptr < image + len - 10; ptr++) {
                 if (strncmp(ptr, "depends=", 8) == 0) {
                         char *u;
@@ -69,12 +71,14 @@ static int FAST_FUNC parse_module(const char *fname, struct stat *sb,
                                 if (*u == '-')
                                         *u = '_';
                         ptr += string_to_llist(ptr, &info->dependencies, ",");
-                } else if (ENABLE_FEATURE_MODUTILS_ALIAS &&
-                           strncmp(ptr, "alias=", 6) == 0) {
+                } else if (ENABLE_FEATURE_MODUTILS_ALIAS
+                 && strncmp(ptr, "alias=", 6) == 0
+                ) {
                         llist_add_to(&info->aliases, xstrdup(ptr + 6));
                         ptr += strlen(ptr);
-                } else if (ENABLE_FEATURE_MODUTILS_SYMBOLS &&
-                           strncmp(ptr, "__ksymtab_", 10) == 0) {
+                } else if (ENABLE_FEATURE_MODUTILS_SYMBOLS
+                 && strncmp(ptr, "__ksymtab_", 10) == 0
+                ) {
                         ptr += 10;
                         if (strncmp(ptr, "gpl", 3) == 0 ||
                             strcmp(ptr, "strings") == 0)
@@ -199,10 +203,17 @@ int depmod_main(int argc UNUSED_PARAM, char **argv)
         if (!(option_mask32 & ARG_n))
                 xfreopen_write("modules.alias", stdout);
         for (m = modules; m != NULL; m = m->next) {
+                const char *fname = bb_basename(m->name);
+                int fnlen = strchrnul(fname, '.') - fname;
                 while (m->aliases) {
-                        printf("alias %s %s\n",
+                        /* Last word can well be m->modname instead,
+                         * but depmod from module-init-tools 3.4
+                         * uses module basename, i.e., no s/-/_/g.
+                         * (pathname and .ko.* are still stripped)
+                         * Mimicking that... */
+                        printf("alias %s %.*s\n",
                                 (char*)llist_pop(&m->aliases),
-                                m->modname);
+                                fnlen, fname);
                 }
         }
 #endif
@@ -210,10 +221,12 @@ int depmod_main(int argc UNUSED_PARAM, char **argv)
         if (!(option_mask32 & ARG_n))
                 xfreopen_write("modules.symbols", stdout);
         for (m = modules; m != NULL; m = m->next) {
+                const char *fname = bb_basename(m->name);
+                int fnlen = strchrnul(fname, '.') - fname;
                 while (m->symbols) {
-                        printf("alias symbol:%s %s\n",
+                        printf("alias symbol:%s %.*s\n",
                                 (char*)llist_pop(&m->symbols),
-                                m->modname);
+                                fnlen, fname);
                 }
         }
 #endif
diff --git a/modutils/depmod_process.sh b/modutils/depmod_process.sh
new file mode 100755
index 000000000..f99b09153
--- /dev/null
+++ b/modutils/depmod_process.sh
@@ -0,0 +1,20 @@
+#!/bin/sh
+
+# Depmod output may be hard to diff.
+# This script sorts dependencies within "xx.ko: yy.ko zz.ko" lines,
+# and sorts all lines too.
+# Usage:
+#
+# [./busybox] depmod -n | ./depmod_process.sh | sort >OUTFILE
+#
+# and then you can diff OUTFILEs. Useful for comparing bbox depmod
+# with module-init-tools depmod and such.
+
+while read -r word rest; do
+    if ! test "${word/*:/}"; then
+        echo -n "$word "
+        echo "$rest" | xargs -n1 | sort | xargs
+    else
+        echo "$word $rest";
+    fi
+done
diff --git a/modutils/modutils.c b/modutils/modutils.c
index 0f6cb0f2d..f437a9829 100644
--- a/modutils/modutils.c
+++ b/modutils/modutils.c
@@ -57,7 +57,7 @@ char * FAST_FUNC filename2modname(const char *filename, char *modname)
         from = bb_get_last_path_component_nostrip(filename);
         for (i = 0; i < (MODULE_NAME_LEN-1) && from[i] != '\0' && from[i] != '.'; i++)
                 modname[i] = (from[i] == '-') ? '_' : from[i];
-        modname[i] = 0;
+        modname[i] = '\0';
 
         return modname;
 }