Re: 3.13: BUG: unable to handle kernel paging request at 00000000b4343e88

[Peter Oberparleiter <oberpar@linux.vnet.ibm.com>]

On 22.01.2014 16:33, Meelis Roos wrote:
>> It looks like gcov exploded when running a module's constructors or
>> init function, but I'm unable to work out which module it was :(
> [...]
> 
>> Maybe it's tg3.
>>
>> Could you add `ignore_loglevel' to the kernel boot parameters?  That
>> should make all pr_debug()s come out and they include the module's
>> name.

I'm not sure if this related, but all 3 kernel logs consistently contain
this error message:

> [    0.617401] gcov: could not create file

which should only be shown in case of severe out-of-memory situations or
duplicate object file names.

Could you retry with the following patch applied (2 times if possible)
and send dmesg output?

-----
diff -Naurp a/kernel/gcov/base.c b/kernel/gcov/base.c
--- a/kernel/gcov/base.c
+++ b/kernel/gcov/base.c
@@ -31,6 +31,7 @@ void __gcov_init(struct gcov_info *info)
 {
 	static unsigned int gcov_version;

+	pr_warn("__gcov_init(%s): enter\n", gcov_info_filename(info));
 	mutex_lock(&gcov_lock);
 	if (gcov_version == 0) {
 		gcov_version = gcov_info_version(info);
@@ -48,6 +49,7 @@ void __gcov_init(struct gcov_info *info)
 	if (gcov_events_enabled)
 		gcov_event(GCOV_ADD, info);
 	mutex_unlock(&gcov_lock);
+	pr_warn("__gcov_init(%s): exit\n", gcov_info_filename(info));
 }
 EXPORT_SYMBOL(__gcov_init);

diff -Naurp a/kernel/gcov/fs.c b/kernel/gcov/fs.c
--- a/kernel/gcov/fs.c
+++ b/kernel/gcov/fs.c
@@ -450,7 +450,7 @@ static struct gcov_node *new_node(struct
 	} else
 		node->dentry = debugfs_create_dir(node->name, parent->dentry);
 	if (!node->dentry) {
-		pr_warn("could not create file\n");
+		pr_warn("could not create file (%s)\n", node->name);
 		kfree(node);
 		return NULL;
 	}