Fix some SMP specific issues on MIPS:
- smp_call_function() shouldn't be called with interrupts disabled, but
kgdb_roundup_cpu() fails to actually enable them using local_irq_restore()
as the 'flags' argument passed to it has interrupts already disabled;
- handle_exception() does not enable interrupts prior to __flush_cache_all()
call which also ends up in IPI;
- 'mips_die_head' didn't have its 'lock' field initialized.
While at it, switch to using DEFINE_SPINLOCK() to define 'die_notifier_lock'...
Based on the original patch by Manish Lachwani <[EMAIL PROTECTED]>.
Signed-off-by: Sergei Shtylyov <[EMAIL PROTECTED]>
---
The patch is against the linux_2_6_21_uprev branch, as usual...
arch/mips/kernel/kgdb.c | 5 +++--
arch/mips/kernel/traps.c | 4 ++--
2 files changed, 5 insertions(+), 4 deletions(-)
Index: linux-2.6/arch/mips/kernel/kgdb.c
===================================================================
--- linux-2.6.orig/arch/mips/kernel/kgdb.c
+++ linux-2.6/arch/mips/kernel/kgdb.c
@@ -69,9 +69,9 @@ void kgdb_call_nmi_hook(void *ignored)
void kgdb_roundup_cpus(unsigned long flags)
{
- local_irq_restore(flags);
+ local_irq_enable();
smp_call_function(kgdb_call_nmi_hook, 0, 0, 0);
- local_irq_save(flags);
+ local_irq_disable();
}
static int compute_signal(int tt)
@@ -106,6 +106,7 @@ void handle_exception(struct pt_regs *re
kgdb_handle_exception(0, compute_signal(trap), 0, regs);
/* In SMP mode, __flush_cache_all does IPI */
+ local_irq_enable();
__flush_cache_all();
}
Index: linux-2.6/arch/mips/kernel/traps.c
===================================================================
--- linux-2.6.orig/arch/mips/kernel/traps.c
+++ linux-2.6/arch/mips/kernel/traps.c
@@ -126,8 +126,8 @@ static void show_backtrace(struct task_s
printk("\n");
}
-struct atomic_notifier_head mips_die_head;
-static spinlock_t die_notifier_lock = SPIN_LOCK_UNLOCKED;
+ATOMIC_NOTIFIER_HEAD(mips_die_head);
+DEFINE_SPINLOCK(die_notifier_lock);
int register_die_notifier(struct notifier_block *nb)
{
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