From a77754b4d0731321db266c6c60ffcd7c62757da5 Mon Sep 17 00:00:00 2001 From: "David S. Miller" Date: Mon, 6 Mar 2006 19:59:50 -0800 Subject: [PATCH] [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 --- arch/sparc64/mm/init.c | 5 +++-- arch/sparc64/mm/tsb.c | 1 + include/asm-sparc64/mmu_context.h | 6 +++--- 3 files changed, 7 insertions(+), 5 deletions(-) diff --git a/arch/sparc64/mm/init.c b/arch/sparc64/mm/init.c index 9bbd0bf64af0..a63939347b3d 100644 --- a/arch/sparc64/mm/init.c +++ b/arch/sparc64/mm/init.c @@ -639,9 +639,10 @@ void get_new_mmu_context(struct mm_struct *mm) { 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 @@ void get_new_mmu_context(struct mm_struct *mm) 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(); diff --git a/arch/sparc64/mm/tsb.c b/arch/sparc64/mm/tsb.c index 534ac2819892..f36799b7152c 100644 --- a/arch/sparc64/mm/tsb.c +++ b/arch/sparc64/mm/tsb.c @@ -354,6 +354,7 @@ void tsb_grow(struct mm_struct *mm, unsigned long rss, gfp_t gfp_flags) int init_new_context(struct task_struct *tsk, struct mm_struct *mm) { + spin_lock_init(&mm->context.lock); mm->context.sparc64_ctx_val = 0UL; diff --git a/include/asm-sparc64/mmu_context.h b/include/asm-sparc64/mmu_context.h index 4be40c58e3c1..ca36ea96f64b 100644 --- a/include/asm-sparc64/mmu_context.h +++ b/include/asm-sparc64/mmu_context.h @@ -67,14 +67,14 @@ extern void __flush_tlb_mm(unsigned long, unsigned long); /* Switch the current MM context. Interrupts are disabled. */ static inline void switch_mm(struct mm_struct *old_mm, struct mm_struct *mm, struct task_struct *tsk) { - unsigned long ctx_valid; + unsigned long ctx_valid, flags; int cpu; - spin_lock(&mm->context.lock); + spin_lock_irqsave(&mm->context.lock, flags); ctx_valid = CTX_VALID(mm->context); if (!ctx_valid) get_new_mmu_context(mm); - spin_unlock(&mm->context.lock); + spin_unlock_irqrestore(&mm->context.lock, flags); if (!ctx_valid || (old_mm != mm)) { load_secondary_context(mm); -- 2.20.1