Staging: add TAINT_CRAP for all drivers/staging code

We need to add a flag for all code that is in the drivers/staging/
directory to prevent all other kernel developers from worrying about
issues here, and to notify users that the drivers might not be as good
as they are normally used to.

Based on code from Andreas Gruenbacher and Jeff Mahoney to provide a
TAINT flag for the support level of a kernel module in the Novell
enterprise kernel release.

This is the kernel portion of this feature, the ability for the flag to
be set needs to be done in the build process and will happen in a
follow-up patch.

Cc: Andreas Gruenbacher <agruen@suse.de>
Cc: Jeff Mahoney <jeffm@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

4 files changed, 17 insertions, 2 deletions

diff --git a/Documentation/sysctl/kernel.txt b/Documentation/sysctl/kernel.txt
index e1ff0d920a5..bde799e0659 100644
--- a/Documentation/sysctl/kernel.txt
+++ b/Documentation/sysctl/kernel.txt
@@ -369,4 +369,5 @@ can be ORed together:
   2 - A module was force loaded by insmod -f.
       Set by modutils >= 2.4.9 and module-init-tools.
   4 - Unsafe SMP processors: SMP with CPUs not designed for SMP.
+ 64 - A module from drivers/staging was loaded.
 
diff --git a/include/linux/kernel.h b/include/linux/kernel.h
index 2651f805ba6..b36805cb95f 100644
--- a/include/linux/kernel.h
+++ b/include/linux/kernel.h
@@ -260,6 +260,7 @@ extern enum system_states {
 #define TAINT_DIE			(1<<7)
 #define TAINT_OVERRIDDEN_ACPI_TABLE	(1<<8)
 #define TAINT_WARN			(1<<9)
+#define TAINT_CRAP			(1<<10)
 
 extern void dump_stack(void) __cold;
 
diff --git a/kernel/module.c b/kernel/module.c
index 9db11911e04..152b1655bba 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -1806,6 +1806,7 @@ static noinline struct module *load_module(void __user *umod,
 	Elf_Ehdr *hdr;
 	Elf_Shdr *sechdrs;
 	char *secstrings, *args, *modmagic, *strtab = NULL;
+	char *staging;
 	unsigned int i;
 	unsigned int symindex = 0;
 	unsigned int strindex = 0;
@@ -1960,6 +1961,14 @@ static noinline struct module *load_module(void __user *umod,
 		goto free_hdr;
 	}
 
+	staging = get_modinfo(sechdrs, infoindex, "staging");
+	if (staging) {
+		add_taint_module(mod, TAINT_CRAP);
+		printk(KERN_WARNING "%s: module is from the staging directory,"
+		       " the quality is unknown, you have been warned.\n",
+		       mod->name);
+	}
+
 	/* Now copy in args */
 	args = strndup_user(uargs, ~0UL >> 1);
 	if (IS_ERR(args)) {
@@ -2556,6 +2565,8 @@ static char *module_flags(struct module *mod, char *buf)
 			buf[bx++] = 'P';
 		if (mod->taints & TAINT_FORCED_MODULE)
 			buf[bx++] = 'F';
+		if (mod->taints & TAINT_CRAP)
+			buf[bx++] = 'C';
 		/*
 		 * TAINT_FORCED_RMMOD: could be added.
 		 * TAINT_UNSAFE_SMP, TAINT_MACHINE_CHECK, TAINT_BAD_PAGE don't
diff --git a/kernel/panic.c b/kernel/panic.c
index 12c5a0a6c89..98e2047f4db 100644
--- a/kernel/panic.c
+++ b/kernel/panic.c
@@ -155,6 +155,7 @@ EXPORT_SYMBOL(panic);
  *  'U' - Userspace-defined naughtiness.
  *  'A' - ACPI table overridden.
  *  'W' - Taint on warning.
+ *  'C' - modules from drivers/staging are loaded.
  *
  *	The string is overwritten by the next call to print_taint().
  */
@@ -163,7 +164,7 @@ const char *print_tainted(void)
 {
 	static char buf[20];
 	if (tainted) {
-		snprintf(buf, sizeof(buf), "Tainted: %c%c%c%c%c%c%c%c%c%c",
+		snprintf(buf, sizeof(buf), "Tainted: %c%c%c%c%c%c%c%c%c%c%c",
 			tainted & TAINT_PROPRIETARY_MODULE ? 'P' : 'G',
 			tainted & TAINT_FORCED_MODULE ? 'F' : ' ',
 			tainted & TAINT_UNSAFE_SMP ? 'S' : ' ',
@@ -173,7 +174,8 @@ const char *print_tainted(void)
 			tainted & TAINT_USER ? 'U' : ' ',
 			tainted & TAINT_DIE ? 'D' : ' ',
 			tainted & TAINT_OVERRIDDEN_ACPI_TABLE ? 'A' : ' ',
-			tainted & TAINT_WARN ? 'W' : ' ');
+			tainted & TAINT_WARN ? 'W' : ' ',
+			tainted & TAINT_CRAP ? 'C' : ' ');
 	}
 	else
 		snprintf(buf, sizeof(buf), "Not tainted");