To keep balance in future, __update_tlb() remember to pte_unmap() after
pte_offset_map(). This is an odd case, since the caller has already done
pte_offset_map_lock(), then mips forgets the address and recalculates it;
but my two naive attempts to clean that up did more harm than good.
Tested-by: Nathan Chancellor <nathan@xxxxxxxxxx>
Signed-off-by: Hugh Dickins <hughd@xxxxxxxxxx>
---
Andrew, please replace my mips patch, and its build warning fix patch,
in mm-unstable by this less ambitious but working replacement - thanks.
arch/mips/mm/tlb-r4k.c | 12 ++++++++++--
1 file changed, 10 insertions(+), 2 deletions(-)
diff --git a/arch/mips/mm/tlb-r4k.c b/arch/mips/mm/tlb-r4k.c
index 1b939abbe4ca..93c2d695588a 100644
--- a/arch/mips/mm/tlb-r4k.c
+++ b/arch/mips/mm/tlb-r4k.c
@@ -297,7 +297,7 @@ void __update_tlb(struct vm_area_struct * vma, unsigned long address, pte_t pte)
p4d_t *p4dp;
pud_t *pudp;
pmd_t *pmdp;
- pte_t *ptep;
+ pte_t *ptep, *ptemap = NULL;
int idx, pid;
/*
@@ -344,7 +344,12 @@ void __update_tlb(struct vm_area_struct * vma, unsigned long address, pte_t pte)
} else
#endif
{
- ptep = pte_offset_map(pmdp, address);
+ ptemap = ptep = pte_offset_map(pmdp, address);
+ /*
+ * update_mmu_cache() is called between pte_offset_map_lock()
+ * and pte_unmap_unlock(), so we can assume that ptep is not
+ * NULL here: and what should be done below if it were NULL?
+ */
#if defined(CONFIG_PHYS_ADDR_T_64BIT) && defined(CONFIG_CPU_MIPS32)
#ifdef CONFIG_XPA
@@ -373,6 +378,9 @@ void __update_tlb(struct vm_area_struct * vma, unsigned long address, pte_t pte)
tlbw_use_hazard();
htw_start();
flush_micro_tlb_vm(vma);
+
+ if (ptemap)
+ pte_unmap(ptemap);
local_irq_restore(flags);
}
--
2.35.3
