diff options
author | David S. Miller <davem@davemloft.net> | 2014-10-10 15:49:16 -0400 |
---|---|---|
committer | David S. Miller <davem@davemloft.net> | 2014-10-10 15:49:16 -0400 |
commit | bdcf81b658ebc4c2640c3c2c55c8b31c601b6996 (patch) | |
tree | c465e00b7e94c54ed09fe13194d4b30185f9eea3 | |
parent | 1cef94c36bd4d79b5ae3a3df99ee0d76d6a4a6dc (diff) |
sparc64: Fix lockdep warnings on reboot on Ultra-5
Inconsistently, the raw_* IRQ routines do not interact with and update
the irqflags tracing and lockdep state, whereas the raw_* spinlock
interfaces do.
This causes problems in p1275_cmd_direct() because we disable hardirqs
by hand using raw_local_irq_restore() and then do a raw_spin_lock()
which triggers a lockdep trace because the CPU's hw IRQ state doesn't
match IRQ tracing's internal software copy of that state.
The CPU's irqs are disabled, yet current->hardirqs_enabled is true.
====================
reboot: Restarting system
------------[ cut here ]------------
WARNING: CPU: 0 PID: 1 at kernel/locking/lockdep.c:3536 check_flags+0x7c/0x240()
DEBUG_LOCKS_WARN_ON(current->hardirqs_enabled)
Modules linked in: openpromfs
CPU: 0 PID: 1 Comm: systemd-shutdow Tainted: G W 3.17.0-dirty #145
Call Trace:
[000000000045919c] warn_slowpath_common+0x5c/0xa0
[0000000000459210] warn_slowpath_fmt+0x30/0x40
[000000000048f41c] check_flags+0x7c/0x240
[0000000000493280] lock_acquire+0x20/0x1c0
[0000000000832b70] _raw_spin_lock+0x30/0x60
[000000000068f2fc] p1275_cmd_direct+0x1c/0x60
[000000000068ed28] prom_reboot+0x28/0x40
[000000000043610c] machine_restart+0x4c/0x80
[000000000047d2d4] kernel_restart+0x54/0x80
[000000000047d618] SyS_reboot+0x138/0x200
[00000000004060b4] linux_sparc_syscall32+0x34/0x60
---[ end trace 5c439fe81c05a100 ]---
possible reason: unannotated irqs-off.
irq event stamp: 2010267
hardirqs last enabled at (2010267): [<000000000049a358>] vprintk_emit+0x4b8/0x580
hardirqs last disabled at (2010266): [<0000000000499f08>] vprintk_emit+0x68/0x580
softirqs last enabled at (2010046): [<000000000045d278>] __do_softirq+0x378/0x4a0
softirqs last disabled at (2010039): [<000000000042bf08>] do_softirq_own_stack+0x28/0x40
Resetting ...
====================
Use local_* variables of the hw IRQ interfaces so that IRQ tracing sees
all of our changes.
Reported-by: Meelis Roos <mroos@linux.ee>
Tested-by: Meelis Roos <mroos@linux.ee>
Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r-- | arch/sparc/prom/p1275.c | 7 |
1 files changed, 4 insertions, 3 deletions
diff --git a/arch/sparc/prom/p1275.c b/arch/sparc/prom/p1275.c index e58b81726319..b2340f008ae0 100644 --- a/arch/sparc/prom/p1275.c +++ b/arch/sparc/prom/p1275.c | |||
@@ -9,6 +9,7 @@ | |||
9 | #include <linux/smp.h> | 9 | #include <linux/smp.h> |
10 | #include <linux/string.h> | 10 | #include <linux/string.h> |
11 | #include <linux/spinlock.h> | 11 | #include <linux/spinlock.h> |
12 | #include <linux/irqflags.h> | ||
12 | 13 | ||
13 | #include <asm/openprom.h> | 14 | #include <asm/openprom.h> |
14 | #include <asm/oplib.h> | 15 | #include <asm/oplib.h> |
@@ -36,8 +37,8 @@ void p1275_cmd_direct(unsigned long *args) | |||
36 | { | 37 | { |
37 | unsigned long flags; | 38 | unsigned long flags; |
38 | 39 | ||
39 | raw_local_save_flags(flags); | 40 | local_save_flags(flags); |
40 | raw_local_irq_restore((unsigned long)PIL_NMI); | 41 | local_irq_restore((unsigned long)PIL_NMI); |
41 | raw_spin_lock(&prom_entry_lock); | 42 | raw_spin_lock(&prom_entry_lock); |
42 | 43 | ||
43 | prom_world(1); | 44 | prom_world(1); |
@@ -45,7 +46,7 @@ void p1275_cmd_direct(unsigned long *args) | |||
45 | prom_world(0); | 46 | prom_world(0); |
46 | 47 | ||
47 | raw_spin_unlock(&prom_entry_lock); | 48 | raw_spin_unlock(&prom_entry_lock); |
48 | raw_local_irq_restore(flags); | 49 | local_irq_restore(flags); |
49 | } | 50 | } |
50 | 51 | ||
51 | void prom_cif_init(void *cif_handler, void *cif_stack) | 52 | void prom_cif_init(void *cif_handler, void *cif_stack) |