sched: Remove USER_SCHED

Commit: 7c9414385ebfdd87cc542d4e7e3bb0dbb2d3ce25 upstream
Author: Dhaval Giani <[email protected]>
AuthorDate: Wed Jan 20 13:26:18 2010 +0100

Remove the USER_SCHED feature. It has been scheduled to be removed in 2.6.34 as per http://marc.info/?l=linux-kernel&m=125728479022976&w=2

[trace from referenced thread]

[1046577.884289] general protection fault: 0000 [#1] SMP
[1046577.911332] last sysfs file: /sys/devices/platform/coretemp.7/temp1_input
[1046577.938715] CPU 3
[1046577.965814] Modules linked in: ipt_REJECT xt_tcpudp iptable_filter ip_tables x_tables coretemp k8temp
[1046577.994456] Pid: 38, comm: events/3 Not tainted 2.6.32.27intel #1 X8DT3
[1046578.023166] RIP: 0010:[] [] sched_destroy_group+0x3c/0x10d
[1046578.052639] RSP: 0000:ffff88043e5abe10 EFLAGS: 00010097
[1046578.081360] RAX: ffff880139fa5540 RBX: ffff8803d18419c0 RCX: ffff8801d2f8fb78
[1046578.109903] RDX: dead000000200200 RSI: 0000000000000000 RDI: 0000000000000000
[1046578.109905] RBP: 0000000000000246 R08: 0000000000000020 R09: ffffffff816339b8
[1046578.109907] R10: 0000000004e6e5f0 R11: 0000000000000006 R12: ffffffff816339b8
[1046578.109909] R13: ffff8803d63ac4e0 R14: ffff88043e582340 R15: ffffffff8104a216
[1046578.109911] FS: 0000000000000000(0000) GS:ffff880028260000(0000) knlGS:0000000000000000
[1046578.109914] CS: 0010 DS: 0018 ES: 0018 CR0: 000000008005003b
[1046578.109915] CR2: 00007f55ab220000 CR3: 00000001e5797000 CR4: 00000000000006e0
[1046578.109917] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[1046578.109919] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
[1046578.109922] Process events/3 (pid: 38, threadinfo ffff88043e5aa000, task ffff88043e582340)
[1046578.109923] Stack:
[1046578.109924] ffff8803d63ac498 ffff8803d63ac4d8 ffff8803d63ac440 ffffffff8104a2c3
[1046578.109927] <0> ffff88043e5abef8 ffff880028276040 ffff8803d63ac4d8 ffffffff81050395
[1046578.109929] <0> ffff88043e582340 ffff88043e5826c8 ffff88043e582340 ffff88043e5abfd8
[1046578.109932] Call Trace:
[1046578.109938] [] ? cleanup_user_struct+0xad/0xcc
[1046578.109942] [] ? worker_thread+0x148/0x1d4
[1046578.109946] [] ? autoremove_wake_function+0x0/0x2e
[1046578.109948] [] ? worker_thread+0x0/0x1d4
[1046578.109951] [] ? kthread+0x79/0x81
[1046578.109955] [] ? child_rip+0xa/0x20
[1046578.109957] [] ? kthread+0x0/0x81
[1046578.109959] [] ? child_rip+0x0/0x20
[1046578.109961] Code: 3c 00 4c 8b 25 02 98 3d 00 48 89 c5 83 cf ff eb 5c 48 8b 43 10 48 63 f7 48 8b 04 f0 48 8b 90 80 00 00 00 48 8b 48 78 48 89 51 08 <48> 89 0a 48 b9 00 02 20 00 00 00 ad de 48 89 88 80 00 00 00 48
[1046578.109975] RIP [] sched_destroy_group+0x3c/0x10d
[1046578.109979] RSP
[1046578.109981] ---[ end trace 5ebc2944b7872d4a ]---

LKML-Reference: <1263990378.24844.3.camel@localhost>
LKML-Reference: http://marc.info/?l=linux-kernel&m=129466345327931

---
 include/linux/sched.h |   14 +--
 init/Kconfig          |   81 +++++--------
 kernel/ksysfs.c       |    8 --
 kernel/sched.c        |  108 +----------------
 kernel/sys.c          |    5 -
 kernel/user.c         |  305 -------------------------------------------------
 6 files changed, 38 insertions(+), 483 deletions(-)

index 957a25f..c1b6ab9 100644
@@ -728,14 +728,6 @@ struct user_struct {
 	uid_t uid;
 	struct user_namespace *user_ns;
 
-#ifdef CONFIG_USER_SCHED
-	struct task_group *tg;
-#ifdef CONFIG_SYSFS
-	struct kobject kobj;
-	struct delayed_work work;
-#endif
-#endif
-
 #ifdef CONFIG_PERF_EVENTS
 	atomic_long_t locked_vm;
 #endif

@@ -2500,13 +2492,9 @@ extern long sched_getaffinity(pid_t pid, struct cpumask *mask);
 
 extern void normalize_rt_tasks(void);
 
-#ifdef CONFIG_GROUP_SCHED
+#ifdef CONFIG_CGROUP_SCHED
 
 extern struct task_group init_task_group;
-#ifdef CONFIG_USER_SCHED
-extern struct task_group root_task_group;
-extern void set_tg_uid(struct user_struct *user);
-#endif
 
 extern struct task_group *sched_create_group(struct task_group *parent);
 extern void sched_destroy_group(struct task_group *tg);

index 528dd78..9cd2b1c 100644
@@ -176,16 +176,8 @@ static int __init ksysfs_init(void)
 			goto group_exit;
 	}
 
-	/* create the /sys/kernel/uids/ directory */
-	error = uids_sysfs_init();
-	if (error)
-		goto notes_exit;
-
 	return 0;
 
-notes_exit:
-	if (notes_size > 0)
-		sysfs_remove_bin_file(kernel_kobj, &notes_attr);
 group_exit:
 	sysfs_remove_group(kernel_kobj, &kernel_attr_group);
 kset_exit:

index 440ca69..e9512b1 100644
@@ -567,11 +567,6 @@ static int set_user(struct cred *new)
 	if (!new_user)
 		return -EAGAIN;
 
-	if (!task_can_switch_user(new_user, current)) {
-		free_uid(new_user);
-		return -EINVAL;
-	}
-
 	if (atomic_read(&new_user->processes) >=
 				current->signal->rlim[RLIMIT_NPROC].rlim_cur &&
 			new_user != INIT_USER) {

1.7.4

There were a few more patches after this which cleaned up a few things as well. Let me search them out and let you know the commit IDs.

Thanks,
Dhaval

6427462bfa50f50dc6c088c07037264fcc73eca1
32bd7eb5a7f4596c8440dd9440322fe9e686634d
571428be550fbe37160596995e96ad398873fcbd

Thanks!
Dhaval

From: Dan Carpenter <[email protected]>
Date: Mon, 15 Mar 2010 11:21:48 +0300
Subject: sched: Remove some dead code

commit 618765801ebc271fe0ba3eca99fcfd62a1f786e1 upstream.

This was left over from "7c9414385e sched: Remove USER_SCHED"

LKML-Reference: <20100315082148.GD18181@bicker>

---
 kernel/user.c |    2 --
 1 files changed, 0 insertions(+), 2 deletions(-)

index 65be394..8e1c8c0 100644
@@ -170,8 +170,6 @@ struct user_struct *alloc_uid(struct user_namespace *ns, uid_t uid)
 
 	return up;
 
-	put_user_ns(new->user_ns);
-	kmem_cache_free(uid_cachep, new);
 out_unlock:
 	return NULL;
 }

This is a note to let you know that I've just added the patch titled

sched: Remove some dead code

to the 2.6.32-longterm tree which can be found at:

    http://www.kernel.org/git/?p=linux/kernel/git/longterm/longterm-queue-2.6.32.git;a=summary

The filename of the patch is:
sched-remove-some-dead-code.patch
and it can be found in the queue-2.6.32 subdirectory.

If you, or anyone else, feels it should not be added to the 2.6.32 longterm tree, please let <[email protected]> know about it.

From: Dan Carpenter <[email protected]>
Date: Fri, 11 Feb 2011 07:04:45 +0100
Subject: sched: Remove some dead code
To: Dhaval Giani <[email protected]>
Cc: LKML <[email protected]>, Peter Zijlstra <[email protected]>, Ingo Molnar <[email protected]>, Greg Kroah-Hartman <[email protected]>
Message-ID: <[email protected]>

From: Dan Carpenter <[email protected]>

commit 618765801ebc271fe0ba3eca99fcfd62a1f786e1 upstream.

This was left over from "7c9414385e sched: Remove USER_SCHED"

LKML-Reference: <20100315082148.GD18181@bicker>

---
 kernel/user.c |    2 --
 1 file changed, 2 deletions(-)

@@ -170,8 +170,6 @@ struct user_struct *alloc_uid(struct use
 
 	return up;
 
-	put_user_ns(new->user_ns);
-	kmem_cache_free(uid_cachep, new);
 out_unlock:
 	return NULL;
 }

Patches currently in longterm-queue-2.6.32 which might be from [email protected] are

From: Namhyung Kim <[email protected]>
Date: Tue, 26 Oct 2010 14:22:43 -0700
Subject: kernel/user.c: add lock release annotation on free_user()

commit 571428be550fbe37160596995e96ad398873fcbd upstream.

free_user() releases uidhash_lock but was missing annotation. Add it. This removes following sparse warnings:

include/linux/spinlock.h:339:9: warning: context imbalance in 'free_user' - unexpected unlock kernel/user.c:120:6: warning: context imbalance in 'free_uid' - wrong count at exit

---
 kernel/user.c |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)

index 8e1c8c0..1b91701 100644
@@ -91,6 +91,7 @@ static struct user_struct *uid_hash_find(uid_t uid, struct hlist_head *hashent)
  * upon function exit.
  */
 static void free_user(struct user_struct *up, unsigned long flags)
+	__releases(&uidhash_lock)
 {
 	uid_hash_remove(up);
 	spin_unlock_irqrestore(&uidhash_lock, flags);

This is a note to let you know that I've just added the patch titled

kernel/user.c: add lock release annotation on free_user()

to the 2.6.32-longterm tree which can be found at:

    http://www.kernel.org/git/?p=linux/kernel/git/longterm/longterm-queue-2.6.32.git;a=summary

The filename of the patch is:
kernel-user.c-add-lock-release-annotation-on-free_user.patch
and it can be found in the queue-2.6.32 subdirectory.

If you, or anyone else, feels it should not be added to the 2.6.32 longterm tree, please let <[email protected]> know about it.

From: Namhyung Kim <[email protected]>
From: Mike Galbraith <[email protected]>
Date: Fri, 11 Feb 2011 07:07:01 +0100
Subject: kernel/user.c: add lock release annotation on free_user()
To: Dhaval Giani <[email protected]>
Cc: LKML <[email protected]>, Peter Zijlstra <[email protected]>, Ingo Molnar <[email protected]>, Greg Kroah-Hartman <[email protected]>
Message-ID: <[email protected]>

From: Namhyung Kim <[email protected]>

commit 571428be550fbe37160596995e96ad398873fcbd upstream.

free_user() releases uidhash_lock but was missing annotation. Add it. This removes following sparse warnings:

include/linux/spinlock.h:339:9: warning: context imbalance in 'free_user' - unexpected unlock kernel/user.c:120:6: warning: context imbalance in 'free_uid' - wrong count at exit

---
 kernel/user.c |    1 +
 1 file changed, 1 insertion(+)

@@ -91,6 +91,7 @@ static struct user_struct *uid_hash_find
  * upon function exit.
  */
 static void free_user(struct user_struct *up, unsigned long flags)
+	__releases(&uidhash_lock)
 {
 	uid_hash_remove(up);
 	spin_unlock_irqrestore(&uidhash_lock, flags);

Patches currently in longterm-queue-2.6.32 which might be from [email protected] are

This one is already in the series.

-Mike