module,bug: Add TAINT_OOT_MODULE flag for modules not built in-tree

Use of the GPL or a compatible licence doesn't necessarily make the code
any good.  We already consider staging modules to be suspect, and this
should also be true for out-of-tree modules which may receive very
little review.

Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Reviewed-by: Dave Jones <davej@redhat.com>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (patched oops-tracing.txt)

Documentation/oops-tracing.txt

@@ -263,6 +263,8 @@ characters, each representing a particular tainted value.
  12: 'I' if the kernel is working around a severe bug in the platform
      firmware (BIOS or similar).
 
+ 13: 'O' if an externally-built ("out-of-tree") module has been loaded.
+
 The primary reason for the 'Tainted: ' string is to tell kernel
 debuggers if this is a clean kernel or if anything unusual has
 occurred.  Tainting is permanent: even if an offending module is

include/linux/kernel.h

@@ -371,6 +371,7 @@ extern enum system_states {
 #define TAINT_WARN			9
 #define TAINT_CRAP			10
 #define TAINT_FIRMWARE_WORKAROUND	11
+#define TAINT_OOT_MODULE		12
 
 extern const char hex_asc[];
 #define hex_asc_lo(x)	hex_asc[((x) & 0x0f)]

kernel/module.c

@@ -2487,6 +2487,9 @@ static int check_modinfo(struct module *mod, struct load_info *info)
 		return -ENOEXEC;
 	}
 
+	if (!get_modinfo(info, "intree"))
+		add_taint_module(mod, TAINT_OOT_MODULE);
+
 	if (get_modinfo(info, "staging")) {
 		add_taint_module(mod, TAINT_CRAP);
 		printk(KERN_WARNING "%s: module is from the staging directory,"
@@ -3255,6 +3258,8 @@ static char *module_flags(struct module *mod, char *buf)
 		buf[bx++] = '(';
 		if (mod->taints & (1 << TAINT_PROPRIETARY_MODULE))
 			buf[bx++] = 'P';
+		else if (mod->taints & (1 << TAINT_OOT_MODULE))
+			buf[bx++] = 'O';
 		if (mod->taints & (1 << TAINT_FORCED_MODULE))
 			buf[bx++] = 'F';
 		if (mod->taints & (1 << TAINT_CRAP))

kernel/panic.c

@@ -177,6 +177,7 @@ static const struct tnt tnts[] = {
 	{ TAINT_WARN,			'W', ' ' },
 	{ TAINT_CRAP,			'C', ' ' },
 	{ TAINT_FIRMWARE_WORKAROUND,	'I', ' ' },
+	{ TAINT_OOT_MODULE,		'O', ' ' },
 };
 
 /**
@@ -194,6 +195,7 @@ static const struct tnt tnts[] = {
  *  'W' - Taint on warning.
  *  'C' - modules from drivers/staging are loaded.
  *  'I' - Working around severe firmware bug.
+ *  'O' - Out-of-tree module has been loaded.
  *
  *	The string is overwritten by the next call to print_tainted().
  */

scripts/mod/modpost.c

@@ -1849,6 +1849,12 @@ static void add_header(struct buffer *b, struct module *mod)
 	buf_printf(b, "};\n");
 }
 
+static void add_intree_flag(struct buffer *b, int is_intree)
+{
+	if (is_intree)
+		buf_printf(b, "\nMODULE_INFO(intree, \"Y\");\n");
+}
+
 static void add_staging_flag(struct buffer *b, const char *name)
 {
 	static const char *staging_dir = "drivers/staging";
@@ -2169,6 +2175,7 @@ int main(int argc, char **argv)
 		buf.pos = 0;
 
 		add_header(&buf, mod);
+		add_intree_flag(&buf, !external_module);
 		add_staging_flag(&buf, mod->name);
 		err |= add_versions(&buf, mod);
 		add_depends(&buf, mod, modules);