[SPARC64]: Bulletproof MMU context locking.
1) Always spin_lock_init() in init_context(). The caller essentially
clears it out, or copies the mm info from the parent. In both
cases we need to explicitly initialize the spinlock.
2) Always do explicit IRQ disabling while taking mm->context.lock
and ctx_alloc_lock.
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/arch/sparc64/mm/init.c b/arch/sparc64/mm/init.c
index 9bbd0bf6..a639393 100644
--- a/arch/sparc64/mm/init.c
+++ b/arch/sparc64/mm/init.c
@@ -639,9 +639,10 @@
{
unsigned long ctx, new_ctx;
unsigned long orig_pgsz_bits;
+ unsigned long flags;
int new_version;
- spin_lock(&ctx_alloc_lock);
+ spin_lock_irqsave(&ctx_alloc_lock, flags);
orig_pgsz_bits = (mm->context.sparc64_ctx_val & CTX_PGSZ_MASK);
ctx = (tlb_context_cache + 1) & CTX_NR_MASK;
new_ctx = find_next_zero_bit(mmu_context_bmap, 1 << CTX_NR_BITS, ctx);
@@ -677,7 +678,7 @@
out:
tlb_context_cache = new_ctx;
mm->context.sparc64_ctx_val = new_ctx | orig_pgsz_bits;
- spin_unlock(&ctx_alloc_lock);
+ spin_unlock_irqrestore(&ctx_alloc_lock, flags);
if (unlikely(new_version))
smp_new_mmu_context_version();