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authorDavid S. Miller <davem@davemloft.net>2014-10-10 15:49:16 -0400
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2014-10-30 09:40:20 -0700
commit67d9e5d4ba691a3b22dc2ec1a5b921e2f874526a (patch)
tree4e50a2eaf4df9188c5043b9ca838e902b80b4773
parent445fd8f9d84ce4cd57992af5dba56953940d415c (diff)
downloadlinux-linaro-stable-67d9e5d4ba691a3b22dc2ec1a5b921e2f874526a.tar.gz
sparc64: Fix lockdep warnings on reboot on Ultra-5
[ Upstream commit bdcf81b658ebc4c2640c3c2c55c8b31c601b6996 ] 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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--arch/sparc/prom/p1275.c7
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 @@
#include <linux/smp.h>
#include <linux/string.h>
#include <linux/spinlock.h>
+#include <linux/irqflags.h>
#include <asm/openprom.h>
#include <asm/oplib.h>
@@ -36,8 +37,8 @@ void p1275_cmd_direct(unsigned long *args)
{
unsigned long flags;
- raw_local_save_flags(flags);
- raw_local_irq_restore((unsigned long)PIL_NMI);
+ local_save_flags(flags);
+ local_irq_restore((unsigned long)PIL_NMI);
raw_spin_lock(&prom_entry_lock);
prom_world(1);
@@ -45,7 +46,7 @@ void p1275_cmd_direct(unsigned long *args)
prom_world(0);
raw_spin_unlock(&prom_entry_lock);
- raw_local_irq_restore(flags);
+ local_irq_restore(flags);
}
void prom_cif_init(void *cif_handler, void *cif_stack)