[PATCH RT 0/3] [ANNOUNCE] 3.0.25-rt44-rc2

[PATCH RT 0/3] [ANNOUNCE] 3.0.25-rt44-rc2

[Steven Rostedt]

Dear RT Folks,

This is the RT stable review cycle of patch 3.0.25-rt44-rc2.

This release added the patch from 3.2-rt:
   printk-disable-migration-instead-of-preemption.patch
as Luis Claudio R. Goncalves pointed out as missing.
 
Please scream at me if I messed something up. Please test the patches too.

The -rc release will be uploaded to kernel.org and will be deleted when
the final release is out. This is just a review release (or release candidate).

The pre-releases will not be pushed to the git repository, only the
final release is.

If all goes well, this patch will be converted to the next main release
on 3/23/2012.

Enjoy,

-- Steve


To build 3.0.25-rt44-rc2 directly, the following patches should be applied:

  http://www.kernel.org/pub/linux/kernel/v3.0/linux-3.0.tar.xz

  http://www.kernel.org/pub/linux/kernel/v3.0/patch-3.0.25.xz

  http://www.kernel.org/pub/linux/kernel/projects/rt/3.0/patch-3.0.25-rt44-rc2.patch.xz

You can also build from 3.0.25-rt43 by applying the incremental patch:

http://www.kernel.org/pub/linux/kernel/projects/rt/3.0/incr/patch-3.0.25-rt43-rt44-rc2.patch.xz


Changes from 3.0.25-rt43:

---


Richard Weinberger (1):
      printk: Disable migration instead of preemption

Steven Rostedt (2):
      Revert "kprobes: adjust "fix a memory leak in function pre_handler_kretprobe()""
      Linux 3.0.25-rt44-rc2

----
 kernel/kprobes.c |    4 ++--
 kernel/printk.c  |    4 ++--
 localversion-rt  |    2 +-
 3 files changed, 5 insertions(+), 5 deletions(-)

[PATCH RT 1/3] Revert "kprobes: adjust "fix a memory leak in function pre_handler_kretprobe()""

[Steven Rostedt]

[-- Attachment #1: 0001-Revert-kprobes-adjust-fix-a-memory-leak-in-function-.patch --]
[-- Type: text/plain, Size: 1303 bytes --]

From: Steven Rostedt <srostedt@redhat.com>

This reverts commit b8a0040ef7112439ad2efac6f1a79aa842b5924f.

As pointed out by John Kacur, the patch breaks 3.0-rt.

Because rt pulls in 7b8d0e5, the above fix which comes from v3.0.24
should not be applied. kretprobe is a raw_spinlock_t for real-time.

Before the revert we get the following compile errors

kernel/kprobes.c:1664: warning: passing argument 1 of 'rt_spin_lock' from incompatible pointer type
kernel/kprobes.c:1666: warning: passing argument 1 of 'rt_spin_unlock' from incompatible pointer type

Signed-off-by: John Kacur <jkacur@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
---
 kernel/kprobes.c |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/kernel/kprobes.c b/kernel/kprobes.c
index a7dcf06..9cdbf26 100644
--- a/kernel/kprobes.c
+++ b/kernel/kprobes.c
@@ -1661,9 +1661,9 @@ static int __kprobes pre_handler_kretprobe(struct kprobe *p,
 		ri->task = current;
 
 		if (rp->entry_handler && rp->entry_handler(ri, regs)) {
-			spin_lock_irqsave(&rp->lock, flags);
+			raw_spin_lock_irqsave(&rp->lock, flags);
 			hlist_add_head(&ri->hlist, &rp->free_instances);
-			spin_unlock_irqrestore(&rp->lock, flags);
+			raw_spin_unlock_irqrestore(&rp->lock, flags);
 			return 0;
 		}
 
-- 
1.7.8.3

[PATCH RT 2/3] printk: Disable migration instead of preemption

[Steven Rostedt]

[-- Attachment #1: 0002-printk-Disable-migration-instead-of-preemption.patch --]
[-- Type: text/plain, Size: 2555 bytes --]

From: Richard Weinberger <rw@linutronix.de>

There is no need do disable preemption in vprintk(), disable_migrate()
is sufficient. This fixes the following bug in -rt:

[   14.759233] BUG: sleeping function called from invalid context
at /home/rw/linux-rt/kernel/rtmutex.c:645
[   14.759235] in_atomic(): 1, irqs_disabled(): 0, pid: 547, name: bash
[   14.759244] Pid: 547, comm: bash Not tainted 3.0.12-rt29+ #3
[   14.759246] Call Trace:
[   14.759301]  [<ffffffff8106fade>] __might_sleep+0xeb/0xf0
[   14.759318]  [<ffffffff810ad784>] rt_spin_lock_fastlock.constprop.9+0x21/0x43
[   14.759336]  [<ffffffff8161fef0>] rt_spin_lock+0xe/0x10
[   14.759354]  [<ffffffff81347ad1>] serial8250_console_write+0x81/0x121
[   14.759366]  [<ffffffff8107ecd3>] __call_console_drivers+0x7c/0x93
[   14.759369]  [<ffffffff8107ef31>] _call_console_drivers+0x5c/0x60
[   14.759372]  [<ffffffff8107f7e5>] console_unlock+0x147/0x1a2
[   14.759374]  [<ffffffff8107fd33>] vprintk+0x3ea/0x462
[   14.759383]  [<ffffffff816160e0>] printk+0x51/0x53
[   14.759399]  [<ffffffff811974e4>] ? proc_reg_poll+0x9a/0x9a
[   14.759403]  [<ffffffff81335b42>] __handle_sysrq+0x50/0x14d
[   14.759406]  [<ffffffff81335c8a>] write_sysrq_trigger+0x4b/0x53
[   14.759408]  [<ffffffff81335c3f>] ? __handle_sysrq+0x14d/0x14d
[   14.759410]  [<ffffffff81197583>] proc_reg_write+0x9f/0xbe
[   14.759426]  [<ffffffff811497ec>] vfs_write+0xac/0xf3
[   14.759429]  [<ffffffff8114a9b3>] ? fget_light+0x3a/0x9b
[   14.759431]  [<ffffffff811499db>] sys_write+0x4a/0x6e
[   14.759438]  [<ffffffff81625d52>] system_call_fastpath+0x16/0x1b

Signed-off-by: Richard Weinberger <rw@linutronix.de>
Link: http://lkml.kernel.org/r/1323696956-11445-1-git-send-email-rw@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
---
 kernel/printk.c |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/kernel/printk.c b/kernel/printk.c
index 30dc7f0..60f4290 100644
--- a/kernel/printk.c
+++ b/kernel/printk.c
@@ -900,7 +900,7 @@ asmlinkage int vprintk(const char *fmt, va_list args)
 	boot_delay_msec();
 	printk_delay();
 
-	preempt_disable();
+	migrate_disable();
 	/* This stops the holder of console_sem just where we want him */
 	raw_local_irq_save(flags);
 	this_cpu = smp_processor_id();
@@ -1031,7 +1031,7 @@ asmlinkage int vprintk(const char *fmt, va_list args)
 out_restore_irqs:
 	raw_local_irq_restore(flags);
 
-	preempt_enable();
+	migrate_enable();
 	return printed_len;
 }
 EXPORT_SYMBOL(printk);
-- 
1.7.8.3

[PATCH RT 3/3] Linux 3.0.25-rt44-rc2

[Steven Rostedt]

[-- Attachment #1: 0003-Linux-3.0.25-rt44-rc2.patch --]
[-- Type: text/plain, Size: 291 bytes --]

From: Steven Rostedt <srostedt@redhat.com>

---
 localversion-rt |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/localversion-rt b/localversion-rt
index 41f7b99..51ced4c 100644
--- a/localversion-rt
+++ b/localversion-rt
@@ -1 +1 @@
--rt43
+-rt44-rc2
-- 
1.7.8.3