[PATCH] list module taint flags in Oops/panic

When listing loaded modules during an oops or panic, also list each
module's Tainted flags if non-zero (P: Proprietary or F: Forced load only).

If a module is did not taint the kernel, it is just listed like
	usbcore
but if it did taint the kernel, it is listed like
	wizmodem(PF)

Example:
[ 3260.121718] Unable to handle kernel NULL pointer dereference at 0000000000000000 RIP:
[ 3260.121729]  [<ffffffff8804c099>] :dump_test:proc_dump_test+0x99/0xc8
[ 3260.121742] PGD fe8d067 PUD 264a6067 PMD 0
[ 3260.121748] Oops: 0002 [1] SMP
[ 3260.121753] CPU 1
[ 3260.121756] Modules linked in: dump_test(P) snd_pcm_oss snd_mixer_oss snd_seq snd_seq_device ide_cd generic ohci1394 snd_hda_intel snd_hda_codec snd_pcm snd_timer snd ieee1394 snd_page_alloc piix ide_core arcmsr aic79xx scsi_transport_spi usblp
[ 3260.121785] Pid: 5556, comm: bash Tainted: P      2.6.18-git10 #1

[Alternatively, I can look into listing tainted flags with 'lsmod',
but that won't help in oopsen/panics so much.]

[akpm@osdl.org: cleanup]
Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

2 files changed, 36 insertions, 3 deletions

diff --git a/include/linux/module.h b/include/linux/module.h
index 2c599175c583..4b2d8091a410 100644
--- a/include/linux/module.h
+++ b/include/linux/module.h
@@ -320,6 +320,8 @@ struct module
         /* Am I GPL-compatible */
         int license_gplok;
 
+        unsigned int taints;    /* same bits as kernel:tainted */
+
 #ifdef CONFIG_MODULE_UNLOAD
         /* Reference counts */
         struct module_ref ref[NR_CPUS];
diff --git a/kernel/module.c b/kernel/module.c
index 05625d5dc758..7c77a0a9275c 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -851,6 +851,7 @@ static int check_version(Elf_Shdr *sechdrs,
                 printk("%s: no version for \"%s\" found: kernel tainted.\n",
                        mod->name, symname);
                 add_taint(TAINT_FORCED_MODULE);
+                mod->taints |= TAINT_FORCED_MODULE;
         }
         return 1;
 }
@@ -1339,6 +1340,7 @@ static void set_license(struct module *mod, const char *license)
                 printk(KERN_WARNING "%s: module license '%s' taints kernel.\n",
                        mod->name, license);
                 add_taint(TAINT_PROPRIETARY_MODULE);
+                mod->taints |= TAINT_PROPRIETARY_MODULE;
         }
 }
 
@@ -1618,6 +1620,7 @@ static struct module *load_module(void __user *umod,
         /* This is allowed: modprobe --force will invalidate it. */
         if (!modmagic) {
                 add_taint(TAINT_FORCED_MODULE);
+                mod->taints |= TAINT_FORCED_MODULE;
                 printk(KERN_WARNING "%s: no version magic, tainting kernel.\n",
                        mod->name);
         } else if (!same_magic(modmagic, vermagic)) {
@@ -1711,10 +1714,14 @@ static struct module *load_module(void __user *umod,
         /* Set up license info based on the info section */
         set_license(mod, get_modinfo(sechdrs, infoindex, "license"));
 
-        if (strcmp(mod->name, "ndiswrapper") == 0)
+        if (strcmp(mod->name, "ndiswrapper") == 0) {
                 add_taint(TAINT_PROPRIETARY_MODULE);
-        if (strcmp(mod->name, "driverloader") == 0)
+                mod->taints |= TAINT_PROPRIETARY_MODULE;
+        }
+        if (strcmp(mod->name, "driverloader") == 0) {
                 add_taint(TAINT_PROPRIETARY_MODULE);
+                mod->taints |= TAINT_PROPRIETARY_MODULE;
+        }
 
         /* Set up MODINFO_ATTR fields */
         setup_modinfo(mod, sechdrs, infoindex);
@@ -1760,6 +1767,7 @@ static struct module *load_module(void __user *umod,
                 printk(KERN_WARNING "%s: No versions for exported symbols."
                        " Tainting kernel.\n", mod->name);
                 add_taint(TAINT_FORCED_MODULE);
+                mod->taints |= TAINT_FORCED_MODULE;
         }
 #endif
 
@@ -2226,14 +2234,37 @@ struct module *module_text_address(unsigned long addr)
         return mod;
 }
 
+static char *taint_flags(unsigned int taints, char *buf)
+{
+        *buf = '\0';
+        if (taints) {
+                int bx;
+
+                buf[0] = '(';
+                bx = 1;
+                if (taints & TAINT_PROPRIETARY_MODULE)
+                        buf[bx++] = 'P';
+                if (taints & TAINT_FORCED_MODULE)
+                        buf[bx++] = 'F';
+                /*
+                 * TAINT_FORCED_RMMOD: could be added.
+                 * TAINT_UNSAFE_SMP, TAINT_MACHINE_CHECK, TAINT_BAD_PAGE don't
+                 * apply to modules.
+                 */
+                buf[bx] = ')';
+        }
+        return buf;
+}
+
 /* Don't grab lock, we're oopsing. */
 void print_modules(void)
 {
         struct module *mod;
+        char buf[8];
 
         printk("Modules linked in:");
         list_for_each_entry(mod, &modules, list)
-                printk(" %s", mod->name);
+                printk(" %s%s", mod->name, taint_flags(mod->taints, buf));
         printk("\n");
 }