linux-kernel - [RFC][PATCH RT] acpi/rt: Convert acpi lock back to a raw_spinlock

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Date:	Wed, 13 Feb 2013 09:26:05 -0500
From:	Steven Rostedt <rostedt@...dmis.org>
To:	LKML <linux-kernel@...r.kernel.org>,
	RT <linux-rt-users@...r.kernel.org>
Cc:	Thomas Gleixner <tglx@...utronix.de>,
	John Kacur <jkacur@...il.com>,
	Clark Williams <clark@...hat.com>
Subject: [RFC][PATCH RT] acpi/rt: Convert acpi lock back to a raw_spinlock_t

We hit the following bug with 3.6-rt:

[    5.898990] BUG: scheduling while atomic: swapper/3/0/0x00000002 
[    5.898991] no locks held by swapper/3/0. 
[    5.898993] Modules linked in: 
[    5.898996] Pid: 0, comm: swapper/3 Not tainted 3.6.11-rt28.19.el6rt.x86_64.debug #1 
[    5.898997] Call Trace: 
[    5.899011]  [<ffffffff810804e7>] __schedule_bug+0x67/0x90 
[    5.899028]  [<ffffffff81577923>] __schedule+0x793/0x7a0 
[    5.899032]  [<ffffffff810b4e40>] ? debug_rt_mutex_print_deadlock+0x50/0x200 
[    5.899034]  [<ffffffff81577b89>] schedule+0x29/0x70 
[    5.899036] BUG: scheduling while atomic: swapper/7/0/0x00000002 
[    5.899037] no locks held by swapper/7/0. 
[    5.899039]  [<ffffffff81578525>] rt_spin_lock_slowlock+0xe5/0x2f0 
[    5.899040] Modules linked in: 
[    5.899041]  
[    5.899045]  [<ffffffff81579a58>] ? _raw_spin_unlock_irqrestore+0x38/0x90 
[    5.899046] Pid: 0, comm: swapper/7 Not tainted 3.6.11-rt28.19.el6rt.x86_64.debug #1 
[    5.899047] Call Trace: 
[    5.899049]  [<ffffffff81578bc6>] rt_spin_lock+0x16/0x40 
[    5.899052]  [<ffffffff810804e7>] __schedule_bug+0x67/0x90 
[    5.899054]  [<ffffffff8157d3f0>] ? notifier_call_chain+0x80/0x80 
[    5.899056]  [<ffffffff81577923>] __schedule+0x793/0x7a0 
[    5.899059]  [<ffffffff812f2034>] acpi_os_acquire_lock+0x1f/0x23 
[    5.899062]  [<ffffffff810b4e40>] ? debug_rt_mutex_print_deadlock+0x50/0x200 
[    5.899068]  [<ffffffff8130be64>] acpi_write_bit_register+0x33/0xb0 
[    5.899071]  [<ffffffff81577b89>] schedule+0x29/0x70 
[    5.899072]  [<ffffffff8130be13>] ? acpi_read_bit_register+0x33/0x51 
[    5.899074]  [<ffffffff81578525>] rt_spin_lock_slowlock+0xe5/0x2f0 
[    5.899077]  [<ffffffff8131d1fc>] acpi_idle_enter_bm+0x8a/0x28e 
[    5.899079]  [<ffffffff81579a58>] ? _raw_spin_unlock_irqrestore+0x38/0x90 
[    5.899081]  [<ffffffff8107e5da>] ? this_cpu_load+0x1a/0x30 
[    5.899083]  [<ffffffff81578bc6>] rt_spin_lock+0x16/0x40 
[    5.899087]  [<ffffffff8144c759>] cpuidle_enter+0x19/0x20 
[    5.899088]  [<ffffffff8157d3f0>] ? notifier_call_chain+0x80/0x80 
[    5.899090]  [<ffffffff8144c777>] cpuidle_enter_state+0x17/0x50 
[    5.899092]  [<ffffffff812f2034>] acpi_os_acquire_lock+0x1f/0x23 
[    5.899094]  [<ffffffff8144d1a1>] cpuidle899101]  [<ffffffff8130be13>] ? 

As the acpi code disables interrupts in acpi_idle_enter_bm, and calls
code that grabs the acpi lock, it causes issues as the lock is currently
in RT a sleeping lock.

The lock was converted from a raw to a sleeping lock due to some
previous issues, and tests that showed it didn't seem to matter.
Unfortunately, it did matter for one of our boxes.

This patch converts the lock back to a raw lock. I've run this code on a
few of my own machines, one being my laptop that uses the acpi quite
extensively. I've been able to suspend and resume without issues.

But as it may have issues still with other hardware, I'm posting this as
an RFC.

Signed-off-by: Steven Rostedt <rostedt@...dmis.org>

diff --git a/drivers/acpi/osl.c b/drivers/acpi/osl.c
index 9eaf708..83d38ed 100644
--- a/drivers/acpi/osl.c
+++ b/drivers/acpi/osl.c
@@ -1432,7 +1432,7 @@ void acpi_os_delete_lock(acpi_spinlock handle)
 acpi_cpu_flags acpi_os_acquire_lock(acpi_spinlock lockp)
 {
 	acpi_cpu_flags flags;
-	spin_lock_irqsave(lockp, flags);
+	raw_spin_lock_irqsave(lockp, flags);
 	return flags;
 }
 
@@ -1442,7 +1442,7 @@ acpi_cpu_flags acpi_os_acquire_lock(acpi_spinlock lockp)
 
 void acpi_os_release_lock(acpi_spinlock lockp, acpi_cpu_flags flags)
 {
-	spin_unlock_irqrestore(lockp, flags);
+	raw_spin_unlock_irqrestore(lockp, flags);
 }
 
 #ifndef ACPI_USE_LOCAL_CACHE
diff --git a/include/acpi/platform/aclinux.h b/include/acpi/platform/aclinux.h
index 7509be3..484cf8c 100644
--- a/include/acpi/platform/aclinux.h
+++ b/include/acpi/platform/aclinux.h
@@ -71,7 +71,7 @@
 #define strtoul                     simple_strtoul
 
 #define acpi_cache_t                        struct kmem_cache
-#define acpi_spinlock                       spinlock_t *
+#define acpi_spinlock                       raw_spinlock_t *
 #define acpi_cpu_flags                      unsigned long
 
 #else /* !__KERNEL__ */
@@ -170,7 +170,7 @@ static inline void *acpi_os_acquire_object(acpi_cache_t * cache)
 								\
 	if (lock) {						\
 		*(__handle) = lock;				\
-		spin_lock_init(*(__handle));			\
+		raw_spin_lock_init(*(__handle));		\
 	}							\
 	lock ? AE_OK : AE_NO_MEMORY;				\
 })


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/