diff toys/other/modinfo.c @ 877:37e668afd008

Isaac Dunham pointed out that the kernel treats - and _ as identical in module names, so modinfo should too. Made it use mmap() while I was there, and some cosmetic refactoring.
author Rob Landley <rob@landley.net>
date Wed, 24 Apr 2013 03:04:31 -0500
parents 786841fdb1e0
children ac9991f66d0d
line wrap: on
line diff
--- a/toys/other/modinfo.c	Mon Apr 22 01:56:26 2013 -0500
+++ b/toys/other/modinfo.c	Wed Apr 24 03:04:31 2013 -0500
@@ -18,64 +18,72 @@
   char *field;
 )
 
-static const char *modinfo_tags[] = {
+static char *modinfo_tags[] = {
   "alias", "license", "description", "author", "vermagic",
   "srcversion", "intree", "parm", "depends",
 };
 
-static void output_field(const char *field, const char *value)
+static void output_field(char *field, char *value)
 {
   int len;
 
-  if (TT.field && strcmp(TT.field, field) != 0) return;
+  if (TT.field && strcmp(TT.field, field)) return;
 
   len = strlen(field);
 
   if (TT.field) xprintf("%s", value);
   else xprintf("%s:%*s%s", field, 15 - len, "", value);
-  if (toys.optflags & FLAG_0) xwrite(fileno(stdout), "\0", 1);
-  else xputs("");
+  xputc((toys.optflags & FLAG_0) ? 0 : '\n');
 }
 
-
 static void modinfo_file(struct dirtree *dir)
 {
   int fd, len, i;
-  char *buf, *pos;
-  char *full_name;
+  char *buf, *pos, *full_name;
 
   full_name = dirtree_path(dir, NULL);
-
   output_field("filename", full_name);
   fd = xopen(full_name, O_RDONLY);
+  free(full_name);
+
   len = fdlength(fd);
-  buf = xmalloc(len);
-  xreadall(fd, buf, len);
+  if (!(buf = mmap(0, len, PROT_READ, MAP_SHARED, fd, 0)))
+    perror_exit("mmap %s", full_name);
 
-  for (pos = buf; pos < buf + len + 10; pos++) {
+  for (pos = buf; pos < buf+len; pos++) {
     if (*pos) continue;
 
-    for (i = 0; i < sizeof(modinfo_tags) / sizeof(modinfo_tags[0]); i++) {
-      const char *str = modinfo_tags[i];
+    for (i = 0; i < sizeof(modinfo_tags) / sizeof(*modinfo_tags); i++) {
+      char *str = modinfo_tags[i];
       int len = strlen(str);
-      if (strncmp(pos + 1, str, len) == 0 && pos[len + 1] == '=')
-        output_field(str, &pos[len + 2]);
+
+      if (!strncmp(pos+1, str, len) && pos[len+1] == '=') 
+        output_field(str, pos+len+2);
     }
   }
 
-  free(full_name);
-  free(buf);
+  munmap(buf, len);
   close(fd);
 }
 
 static int check_module(struct dirtree *new)
 {
   if (S_ISREG(new->st.st_mode)) {
-    char **s;
-    for (s = toys.optargs; *s; s++) {
-      int len = strlen(*s);
-      if (!strncmp(*s, new->name, len) && !strcmp(new->name+len, ".ko"))
-        modinfo_file(new);
+    char **ss;
+
+    for (ss = toys.optargs; *ss; ss++) {
+      char *s = *ss;
+      int len = 0;
+
+      // The kernel treats - and _ the same, so we should too.
+      for (len = 0; s[len]; len++) {
+        if (s[len] == '-' && new->name[len] == '_') continue;
+        if (s[len] == '_' && new->name[len] == '-') continue;
+        if (s[len] != new->name[len]) break;
+      }
+      if (s[len] || strcmp(new->name+len, ".ko")) break;
+
+      modinfo_file(new);
     }
   }
 
@@ -88,5 +96,6 @@
 
   if (uname(&uts) < 0) perror_exit("bad uname");
   sprintf(toybuf, "/lib/modules/%s", uts.release);
+
   dirtree_read(toybuf, check_module);
 }