3.17-stable review patch. If anyone has any objections, please let me know. ------------------ From: Markos Chandras <markos.chandras@xxxxxxxxxx> commit 6a8dff6ab16c903b0d8ef5fbf21543f39bf5d675 upstream. HTW needs to stop and start again whenever the EntryHI register changes otherwise an inflight HTW operation might use the new EntryHI register for updating an old entry and that could lead to crashes or even a machine check exception. We fix this by ensuring the HTW has stop whenever the EntryHI register is about to change Signed-off-by: Markos Chandras <markos.chandras@xxxxxxxxxx> Cc: linux-mips@xxxxxxxxxxxxxx Patchwork: https://patchwork.linux-mips.org/patch/8511/ Signed-off-by: Ralf Baechle <ralf@xxxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- arch/mips/mm/tlb-r4k.c | 4 ++++ 1 file changed, 4 insertions(+) --- a/arch/mips/mm/tlb-r4k.c +++ b/arch/mips/mm/tlb-r4k.c @@ -299,6 +299,7 @@ void __update_tlb(struct vm_area_struct local_irq_save(flags); + htw_stop(); pid = read_c0_entryhi() & ASID_MASK; address &= (PAGE_MASK << 1); write_c0_entryhi(address | pid); @@ -346,6 +347,7 @@ void __update_tlb(struct vm_area_struct tlb_write_indexed(); } tlbw_use_hazard(); + htw_start(); flush_itlb_vm(vma); local_irq_restore(flags); } @@ -422,6 +424,7 @@ __init int add_temporary_entry(unsigned local_irq_save(flags); /* Save old context and create impossible VPN2 value */ + htw_stop(); old_ctx = read_c0_entryhi(); old_pagemask = read_c0_pagemask(); wired = read_c0_wired(); @@ -443,6 +446,7 @@ __init int add_temporary_entry(unsigned write_c0_entryhi(old_ctx); write_c0_pagemask(old_pagemask); + htw_start(); out: local_irq_restore(flags); return ret;
