[PATCH v2 07/23 replacement] mips: add pte_unmap() to balance pte_offset_map()
Hugh Dickins <[email protected]>
| Newsgroups | gmane.linux.ports.m68k,gmane.linux.ports.arm.kernel,gmane.linux.ports.ia64,gmane.linux.ports.mips,gmane.linux.ports.parisc,gmane.linux.ports.ppc64.devel,gmane.linux.ports.riscv,gmane.linux.ports.sh.devel,gmane.linux.ports.sparc,gmane.linux.kernel,gmane.linux.kernel.mm |
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| Message-ID | <[email protected]> |
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 <[email protected]> Signed-off-by: Hugh Dickins <[email protected]> --- 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