| From | Greg Kroah-Hartman <> | Subject | [PATCH 4.4 57/75] sparc64: Take ctx_alloc_lock properly in hugetlb_setup(). | Date | Wed, 22 Jun 2016 15:41:19 -0700 |
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4.4-stable review patch. If anyone has any objections, please let me know.
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From: "David S. Miller" <davem@davemloft.net>
[ Upstream commit 9ea46abe22550e3366ff7cee2f8391b35b12f730 ]
On cheetahplus chips we take the ctx_alloc_lock in order to modify the TLB lookup parameters for the indexed TLBs, which are stored in the context register.
This is called with interrupts disabled, however ctx_alloc_lock is an IRQ safe lock, therefore we must take acquire/release it properly with spin_{lock,unlock}_irq().
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> --- arch/sparc/mm/init_64.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-)
--- a/arch/sparc/mm/init_64.c +++ b/arch/sparc/mm/init_64.c @@ -2821,9 +2821,10 @@ void hugetlb_setup(struct pt_regs *regs) * the Data-TLB for huge pages. */ if (tlb_type == cheetah_plus) { + bool need_context_reload = false; unsigned long ctx; - spin_lock(&ctx_alloc_lock); + spin_lock_irq(&ctx_alloc_lock); ctx = mm->context.sparc64_ctx_val; ctx &= ~CTX_PGSZ_MASK; ctx |= CTX_PGSZ_BASE << CTX_PGSZ0_SHIFT; @@ -2842,9 +2843,12 @@ void hugetlb_setup(struct pt_regs *regs) * also executing in this address space. */ mm->context.sparc64_ctx_val = ctx; - on_each_cpu(context_reload, mm, 0); + need_context_reload = true; } - spin_unlock(&ctx_alloc_lock); + spin_unlock_irq(&ctx_alloc_lock); + + if (need_context_reload) + on_each_cpu(context_reload, mm, 0); } } #endif
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