all,
The wireless network interface has become inoperative when running
linux-next 20141216 on a Lenovo Carbon X1. It is completely
non-existent and `ip addr` doesn't show it. A bisect has found that
the bug was introduced by the following commit.
commit 9d328afb18f05c25686102ad890a67bb3ca38aab
Author: Al Viro <v...@zeniv.linux.org.uk>
Date: Thu Dec 11 22:34:21 2014 -0500
spawn PID 1 without CLONE_FS, give kernel threads zero umask
Don't give PID 1 init_fs, give it a copy of its own when it's
spawned.
Then we can make init_fs.umode zero, and have both the PID 1 and
everything that gets spawned by call_usermodehelper() set
->fs->umask
to old value (0022) early on.
Signed-off-by: Al Viro <v...@zeniv.linux.org.uk>
Below is my network interface information. And the iwlwifi modules are
being used.
$ lspci
...
03:00.0 Network controller: Intel Corporation Centrino Advanced-N 6205
[Taylor Peak] (rev 96)
...
And the patch which introduced this bug is included below.
>From 9d328afb18f05c25686102ad890a67bb3ca38aab Mon Sep 17 00:00:00 2001
From: Al Viro <v...@zeniv.linux.org.uk>
Date: Thu, 11 Dec 2014 22:34:21 -0500
Subject: [PATCH] spawn PID 1 without CLONE_FS, give kernel threads zero umask
Don't give PID 1 init_fs, give it a copy of its own when it's spawned.
Then we can make init_fs.umode zero, and have both the PID 1 and
everything that gets spawned by call_usermodehelper() set ->fs->umask
to old value (0022) early on.
Signed-off-by: Al Viro <v...@zeniv.linux.org.uk>
---
fs/fs_struct.c | 2 +-
init/main.c | 4 +++-
kernel/kmod.c | 2 ++
3 files changed, 6 insertions(+), 2 deletions(-)
diff --git a/fs/fs_struct.c b/fs/fs_struct.c
index 7dca743..2242c40 100644
--- a/fs/fs_struct.c
+++ b/fs/fs_struct.c
@@ -162,5 +162,5 @@ struct fs_struct init_fs = {
.users = 1,
.lock = __SPIN_LOCK_UNLOCKED(init_fs.lock),
.seq = SEQCNT_ZERO(init_fs.seq),
- .umask = 0022,
+ .umask = 0,
};
diff --git a/init/main.c b/init/main.c
index 40240c8..3a169a2 100644
--- a/init/main.c
+++ b/init/main.c
@@ -79,6 +79,7 @@
#include <linux/random.h>
#include <linux/list.h>
#include <linux/proc_ns.h>
+#include <linux/fs_struct.h>
#include <asm/io.h>
#include <asm/bugs.h>
@@ -401,7 +402,7 @@ static noinline void __init_refok rest_init(void)
* the init task will end up wanting to create kthreads, which, if
* we schedule it before we create kthreadd, will OOPS.
*/
- kernel_thread(kernel_init, NULL, CLONE_FS);
+ kernel_thread(kernel_init, NULL, 0);
numa_default_policy();
pid = kernel_thread(kthreadd, NULL, CLONE_FS | CLONE_FILES);
rcu_read_lock();
@@ -933,6 +934,7 @@ static int __ref kernel_init(void *unused)
{
int ret;
+ current->fs->umask = 0022;
kernel_init_freeable();
/* need to finish all async __init code before freeing the memory */
async_synchronize_full();
diff --git a/kernel/kmod.c b/kernel/kmod.c
index 80f7a6d..8879506 100644
--- a/kernel/kmod.c
+++ b/kernel/kmod.c
@@ -39,6 +39,7 @@
#include <linux/rwsem.h>
#include <linux/ptrace.h>
#include <linux/async.h>
+#include <linux/fs_struct.h>
#include <asm/uaccess.h>
#include <trace/events/module.h>
@@ -227,6 +228,7 @@ static int ____call_usermodehelper(void *data)
struct cred *new;
int retval;
+ current->fs->umask = 0022;
spin_lock_irq(¤t->sighand->siglock);
flush_signal_handlers(current, 1);
spin_unlock_irq(¤t->sighand->siglock);
--
2.1.3
Let me know if I can provided any further information that would be helpful.
--
- Jeremiah Mahler
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
