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<title>user/sven/linux.git/kernel/module.c, branch v3.14.11</title>
<subtitle>Linux Kernel
</subtitle>
<id>https://git.stealer.net/cgit.cgi/user/sven/linux.git/atom?h=v3.14.11</id>
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<updated>2014-06-07T17:28:11Z</updated>
<entry>
<title>module: remove warning about waiting module removal.</title>
<updated>2014-06-07T17:28:11Z</updated>
<author>
<name>Rusty Russell</name>
<email>rusty@rustcorp.com.au</email>
</author>
<published>2014-04-28T01:35:43Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=43cbcb5be20cb6f61833bd596c0f74f6c8cc048c'/>
<id>urn:sha1:43cbcb5be20cb6f61833bd596c0f74f6c8cc048c</id>
<content type='text'>
commit 79465d2fd48e68940c2bdecddbdecd45bbba06fe upstream.

We remove the waiting module removal in commit 3f2b9c9cdf38 (September
2013), but it turns out that modprobe in kmod (&lt; version 16) was
asking for waiting module removal.  No one noticed since modprobe would
check for 0 usage immediately before trying to remove the module, and
the race is unlikely.

However, it means that anyone running old (but not ancient) kmod
versions is hitting the printk designed to see if anyone was running
"rmmod -w".  All reports so far have been false positives, so remove
the warning.

Fixes: 3f2b9c9cdf389e303b2273679af08aab5f153517
Reported-by: Valerio Vanni &lt;valerio.vanni@inwind.it&gt;
Cc: Elliott, Robert (Server Storage) &lt;Elliott@hp.com&gt;
Acked-by: Lucas De Marchi &lt;lucas.de.marchi@gmail.com&gt;
Signed-off-by: Rusty Russell &lt;rusty@rustcorp.com.au&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
<entry>
<title>ftrace/module: Hardcode ftrace_module_init() call into load_module()</title>
<updated>2014-06-07T17:28:07Z</updated>
<author>
<name>Steven Rostedt (Red Hat)</name>
<email>rostedt@goodmis.org</email>
</author>
<published>2014-04-24T14:40:12Z</published>
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<id>urn:sha1:d9550cf732c439447abe24655c23fcc27915ff7d</id>
<content type='text'>
commit a949ae560a511fe4e3adf48fa44fefded93e5c2b upstream.

A race exists between module loading and enabling of function tracer.

	CPU 1				CPU 2
	-----				-----
  load_module()
   module-&gt;state = MODULE_STATE_COMING

				register_ftrace_function()
				 mutex_lock(&amp;ftrace_lock);
				 ftrace_startup()
				  update_ftrace_function();
				   ftrace_arch_code_modify_prepare()
				    set_all_module_text_rw();
				   &lt;enables-ftrace&gt;
				    ftrace_arch_code_modify_post_process()
				     set_all_module_text_ro();

				[ here all module text is set to RO,
				  including the module that is
				  loading!! ]

   blocking_notifier_call_chain(MODULE_STATE_COMING);
    ftrace_init_module()

     [ tries to modify code, but it's RO, and fails!
       ftrace_bug() is called]

When this race happens, ftrace_bug() will produces a nasty warning and
all of the function tracing features will be disabled until reboot.

The simple solution is to treate module load the same way the core
kernel is treated at boot. To hardcode the ftrace function modification
of converting calls to mcount into nops. This is done in init/main.c
there's no reason it could not be done in load_module(). This gives
a better control of the changes and doesn't tie the state of the
module to its notifiers as much. Ftrace is special, it needs to be
treated as such.

The reason this would work, is that the ftrace_module_init() would be
called while the module is in MODULE_STATE_UNFORMED, which is ignored
by the set_all_module_text_ro() call.

Link: http://lkml.kernel.org/r/1395637826-3312-1-git-send-email-indou.takao@jp.fujitsu.com

Reported-by: Takao Indoh &lt;indou.takao@jp.fujitsu.com&gt;
Acked-by: Rusty Russell &lt;rusty@rustcorp.com.au&gt;
Signed-off-by: Steven Rostedt &lt;rostedt@goodmis.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
<entry>
<title>module: Add missing newline in printk call.</title>
<updated>2014-01-20T23:29:16Z</updated>
<author>
<name>Tetsuo Handa</name>
<email>penguin-kernel@I-love.SAKURA.ne.jp</email>
</author>
<published>2014-01-20T23:28:00Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=22e669568d5195af10bd2f404f9c1809541ad77b'/>
<id>urn:sha1:22e669568d5195af10bd2f404f9c1809541ad77b</id>
<content type='text'>
Add missing \n and also follow commit bddb12b3 "kernel/module.c: use pr_foo()".

Signed-off-by: Tetsuo Handa &lt;penguin-kernel@I-love.SAKURA.ne.jp&gt;
Signed-off-by: Rusty Russell &lt;rusty@rustcorp.com.au&gt;
</content>
</entry>
<entry>
<title>Merge tag 'modules-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux</title>
<updated>2013-11-15T04:27:50Z</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2013-11-15T04:27:50Z</published>
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<id>urn:sha1:ce6513f758b1852a2f24f76f07d0fae304d24ad3</id>
<content type='text'>
Pull module updates from Rusty Russell:
 "Mainly boring here, too.  rmmod --wait finally removed, though"

* tag 'modules-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux:
  modpost: fix bogus 'exported twice' warnings.
  init: fix in-place parameter modification regression
  asmlinkage, module: Make ksymtab and kcrctab symbols and __this_module __visible
  kernel: add support for init_array constructors
  modpost: Optionally ignore secondary errors seen if a single module build fails
  module: remove rmmod --wait option.
</content>
</entry>
<entry>
<title>kernel/module.c: use pr_foo()</title>
<updated>2013-11-13T03:09:34Z</updated>
<author>
<name>Andrew Morton</name>
<email>akpm@linux-foundation.org</email>
</author>
<published>2013-11-12T23:11:28Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=bddb12b32f90c571b177439a650f1046c3185c2e'/>
<id>urn:sha1:bddb12b32f90c571b177439a650f1046c3185c2e</id>
<content type='text'>
kernel/module.c uses a mix of printk(KERN_foo and pr_foo().  Convert it
all to pr_foo and make the offered cleanups.

Not sure what to do about the printk(KERN_DEFAULT).  We don't have a
pr_default().

Cc: Rusty Russell &lt;rusty@rustcorp.com.au&gt;
Cc: Joe Perches &lt;joe@perches.com&gt;
Cc: Frantisek Hrbata &lt;fhrbata@redhat.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
</entry>
<entry>
<title>kernel: add support for init_array constructors</title>
<updated>2013-10-17T04:35:17Z</updated>
<author>
<name>Frantisek Hrbata</name>
<email>fhrbata@redhat.com</email>
</author>
<published>2013-10-14T07:38:46Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=eb3057df732c304622aee77c450761746939a2dc'/>
<id>urn:sha1:eb3057df732c304622aee77c450761746939a2dc</id>
<content type='text'>
This adds the .init_array section as yet another section with constructors. This
is needed because gcc could add __gcov_init calls to .init_array or .ctors
section, depending on gcc (and binutils) version .

v2: - reuse mod-&gt;ctors for .init_array section for modules, because gcc uses
      .ctors or .init_array, but not both at the same time
v3: - fail to load if that does happen somehow.

Signed-off-by: Frantisek Hrbata &lt;fhrbata@redhat.com&gt;
Signed-off-by: Rusty Russell &lt;rusty@rustcorp.com.au&gt;
</content>
</entry>
<entry>
<title>module: remove rmmod --wait option.</title>
<updated>2013-09-23T06:14:58Z</updated>
<author>
<name>Rusty Russell</name>
<email>rusty@rustcorp.com.au</email>
</author>
<published>2013-09-16T20:18:51Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=3f2b9c9cdf389e303b2273679af08aab5f153517'/>
<id>urn:sha1:3f2b9c9cdf389e303b2273679af08aab5f153517</id>
<content type='text'>
The option to wait for a module reference count to reach zero was in
the initial module implementation, but it was never supported in
modprobe (you had to use rmmod --wait).  After discussion with Lucas,
It has been deprecated (with a 10 second sleep) in kmod for the last
year.

This finally removes it: the flag will evoke a printk warning and a
normal (non-blocking) remove attempt.

Cc: Lucas De Marchi &lt;lucas.de.marchi@gmail.com&gt;
Signed-off-by: Rusty Russell &lt;rusty@rustcorp.com.au&gt;
</content>
</entry>
<entry>
<title>Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs</title>
<updated>2013-09-05T15:50:26Z</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2013-09-05T15:50:26Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=45d9a2220f6004b47c362cc7fc7cf9a73cb6353a'/>
<id>urn:sha1:45d9a2220f6004b47c362cc7fc7cf9a73cb6353a</id>
<content type='text'>
Pull vfs pile 1 from Al Viro:
 "Unfortunately, this merge window it'll have a be a lot of small piles -
  my fault, actually, for not keeping #for-next in anything that would
  resemble a sane shape ;-/

  This pile: assorted fixes (the first 3 are -stable fodder, IMO) and
  cleanups + %pd/%pD formats (dentry/file pathname, up to 4 last
  components) + several long-standing patches from various folks.

  There definitely will be a lot more (starting with Miklos'
  check_submount_and_drop() series)"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (26 commits)
  direct-io: Handle O_(D)SYNC AIO
  direct-io: Implement generic deferred AIO completions
  add formats for dentry/file pathnames
  kvm eventfd: switch to fdget
  powerpc kvm: use fdget
  switch fchmod() to fdget
  switch epoll_ctl() to fdget
  switch copy_module_from_fd() to fdget
  git simplify nilfs check for busy subtree
  ibmasmfs: don't bother passing superblock when not needed
  don't pass superblock to hypfs_{mkdir,create*}
  don't pass superblock to hypfs_diag_create_files
  don't pass superblock to hypfs_vm_create_files()
  oprofile: get rid of pointless forward declarations of struct super_block
  oprofilefs_create_...() do not need superblock argument
  oprofilefs_mkdir() doesn't need superblock argument
  don't bother with passing superblock to oprofile_create_stats_files()
  oprofile: don't bother with passing superblock to -&gt;create_files()
  don't bother passing sb to oprofile_create_files()
  coh901318: don't open-code simple_read_from_buffer()
  ...
</content>
</entry>
<entry>
<title>switch copy_module_from_fd() to fdget</title>
<updated>2013-09-04T03:04:44Z</updated>
<author>
<name>Al Viro</name>
<email>viro@zeniv.linux.org.uk</email>
</author>
<published>2013-08-30T16:41:41Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=a2e0578be3652406b2ffd2eeb31cdbdffa325d64'/>
<id>urn:sha1:a2e0578be3652406b2ffd2eeb31cdbdffa325d64</id>
<content type='text'>
Signed-off-by: Al Viro &lt;viro@zeniv.linux.org.uk&gt;
</content>
</entry>
<entry>
<title>module: Fix mod-&gt;mkobj.kobj potentially freed too early</title>
<updated>2013-09-03T07:05:47Z</updated>
<author>
<name>Li Zhong</name>
<email>zhong@linux.vnet.ibm.com</email>
</author>
<published>2013-09-03T07:03:57Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=942e443127e928a5631c3d5102aca8c8b3c2dd98'/>
<id>urn:sha1:942e443127e928a5631c3d5102aca8c8b3c2dd98</id>
<content type='text'>
DEBUG_KOBJECT_RELEASE helps to find the issue attached below.

After some investigation, it seems the reason is:
The mod-&gt;mkobj.kobj(ffffffffa01600d0 below) is freed together with mod
itself in free_module(). However, its children still hold references to
it, as the delay caused by DEBUG_KOBJECT_RELEASE. So when the
child(holders below) tries to decrease the reference count to its parent
in kobject_del(), BUG happens as it tries to access already freed memory.

This patch tries to fix it by waiting for the mod-&gt;mkobj.kobj to be
really released in the module removing process (and some error code
paths).

[ 1844.175287] kobject: 'holders' (ffff88007c1f1600): kobject_release, parent ffffffffa01600d0 (delayed)
[ 1844.178991] kobject: 'notes' (ffff8800370b2a00): kobject_release, parent ffffffffa01600d0 (delayed)
[ 1845.180118] kobject: 'holders' (ffff88007c1f1600): kobject_cleanup, parent ffffffffa01600d0
[ 1845.182130] kobject: 'holders' (ffff88007c1f1600): auto cleanup kobject_del
[ 1845.184120] BUG: unable to handle kernel paging request at ffffffffa01601d0
[ 1845.185026] IP: [&lt;ffffffff812cda81&gt;] kobject_put+0x11/0x60
[ 1845.185026] PGD 1a13067 PUD 1a14063 PMD 7bd30067 PTE 0
[ 1845.185026] Oops: 0000 [#1] PREEMPT
[ 1845.185026] Modules linked in: xfs libcrc32c [last unloaded: kprobe_example]
[ 1845.185026] CPU: 0 PID: 18 Comm: kworker/0:1 Tainted: G           O 3.11.0-rc6-next-20130819+ #1
[ 1845.185026] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2007
[ 1845.185026] Workqueue: events kobject_delayed_cleanup
[ 1845.185026] task: ffff88007ca51f00 ti: ffff88007ca5c000 task.ti: ffff88007ca5c000
[ 1845.185026] RIP: 0010:[&lt;ffffffff812cda81&gt;]  [&lt;ffffffff812cda81&gt;] kobject_put+0x11/0x60
[ 1845.185026] RSP: 0018:ffff88007ca5dd08  EFLAGS: 00010282
[ 1845.185026] RAX: 0000000000002000 RBX: ffffffffa01600d0 RCX: ffffffff8177d638
[ 1845.185026] RDX: ffff88007ca5dc18 RSI: 0000000000000000 RDI: ffffffffa01600d0
[ 1845.185026] RBP: ffff88007ca5dd18 R08: ffffffff824e9810 R09: ffffffffffffffff
[ 1845.185026] R10: ffff8800ffffffff R11: dead4ead00000001 R12: ffffffff81a95040
[ 1845.185026] R13: ffff88007b27a960 R14: ffff88007c1f1600 R15: 0000000000000000
[ 1845.185026] FS:  0000000000000000(0000) GS:ffffffff81a23000(0000) knlGS:0000000000000000
[ 1845.185026] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
[ 1845.185026] CR2: ffffffffa01601d0 CR3: 0000000037207000 CR4: 00000000000006b0
[ 1845.185026] Stack:
[ 1845.185026]  ffff88007c1f1600 ffff88007c1f1600 ffff88007ca5dd38 ffffffff812cdb7e
[ 1845.185026]  0000000000000000 ffff88007c1f1640 ffff88007ca5dd68 ffffffff812cdbfe
[ 1845.185026]  ffff88007c974800 ffff88007c1f1640 ffff88007ff61a00 0000000000000000
[ 1845.185026] Call Trace:
[ 1845.185026]  [&lt;ffffffff812cdb7e&gt;] kobject_del+0x2e/0x40
[ 1845.185026]  [&lt;ffffffff812cdbfe&gt;] kobject_delayed_cleanup+0x6e/0x1d0
[ 1845.185026]  [&lt;ffffffff81063a45&gt;] process_one_work+0x1e5/0x670
[ 1845.185026]  [&lt;ffffffff810639e3&gt;] ? process_one_work+0x183/0x670
[ 1845.185026]  [&lt;ffffffff810642b3&gt;] worker_thread+0x113/0x370
[ 1845.185026]  [&lt;ffffffff810641a0&gt;] ? rescuer_thread+0x290/0x290
[ 1845.185026]  [&lt;ffffffff8106bfba&gt;] kthread+0xda/0xe0
[ 1845.185026]  [&lt;ffffffff814ff0f0&gt;] ? _raw_spin_unlock_irq+0x30/0x60
[ 1845.185026]  [&lt;ffffffff8106bee0&gt;] ? kthread_create_on_node+0x130/0x130
[ 1845.185026]  [&lt;ffffffff8150751a&gt;] ret_from_fork+0x7a/0xb0
[ 1845.185026]  [&lt;ffffffff8106bee0&gt;] ? kthread_create_on_node+0x130/0x130
[ 1845.185026] Code: 81 48 c7 c7 28 95 ad 81 31 c0 e8 9b da 01 00 e9 4f ff ff ff 66 0f 1f 44 00 00 55 48 89 e5 53 48 89 fb 48 83 ec 08 48 85 ff 74 1d &lt;f6&gt; 87 00 01 00 00 01 74 1e 48 8d 7b 38 83 6b 38 01 0f 94 c0 84
[ 1845.185026] RIP  [&lt;ffffffff812cda81&gt;] kobject_put+0x11/0x60
[ 1845.185026]  RSP &lt;ffff88007ca5dd08&gt;
[ 1845.185026] CR2: ffffffffa01601d0
[ 1845.185026] ---[ end trace 49a70afd109f5653 ]---

Signed-off-by: Li Zhong &lt;zhong@linux.vnet.ibm.com&gt;
Acked-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Signed-off-by: Rusty Russell &lt;rusty@rustcorp.com.au&gt;
</content>
</entry>
</feed>
