[PATCH 12/23] powerpc: allow pte_offset_map[_lock]() to fail
Hugh Dickins <[email protected]>
| Newsgroups | gmane.linux.ports.mips,gmane.linux.ports.arm.kernel,gmane.linux.ports.ia64,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 |
|---|---|
| Message-ID | <[email protected]> |
In rare transient cases, not yet made possible, pte_offset_map() and pte_offset_map_lock() may not find a page table: handle appropriately. Balance successful pte_offset_map() with pte_unmap() where omitted. Signed-off-by: Hugh Dickins <[email protected]> --- arch/powerpc/mm/book3s64/hash_tlb.c | 4 ++++ arch/powerpc/mm/book3s64/subpage_prot.c | 2 ++ arch/powerpc/xmon/xmon.c | 5 ++++- 3 files changed, 10 insertions(+), 1 deletion(-) diff --git a/arch/powerpc/mm/book3s64/hash_tlb.c b/arch/powerpc/mm/book3s64/hash_tlb.c index a64ea0a7ef96..21fcad97ae80 100644 --- a/arch/powerpc/mm/book3s64/hash_tlb.c +++ b/arch/powerpc/mm/book3s64/hash_tlb.c @@ -239,12 +239,16 @@ void flush_hash_table_pmd_range(struct mm_struct *mm, pmd_t *pmd, unsigned long local_irq_save(flags); arch_enter_lazy_mmu_mode(); start_pte = pte_offset_map(pmd, addr); + if (!start_pte) + goto out; for (pte = start_pte; pte < start_pte + PTRS_PER_PTE; pte++) { unsigned long pteval = pte_val(*pte); if (pteval & H_PAGE_HASHPTE) hpte_need_flush(mm, addr, pte, pteval, 0); addr += PAGE_SIZE; } + pte_unmap(start_pte); +out: arch_leave_lazy_mmu_mode(); local_irq_restore(flags); } diff --git a/arch/powerpc/mm/book3s64/subpage_prot.c b/arch/powerpc/mm/book3s64/subpage_prot.c index b75a9fb99599..0dc85556dec5 100644 --- a/arch/powerpc/mm/book3s64/subpage_prot.c +++ b/arch/powerpc/mm/book3s64/subpage_prot.c @@ -71,6 +71,8 @@ static void hpte_flush_range(struct mm_struct *mm, unsigned long addr, if (pmd_none(*pmd)) return; pte = pte_offset_map_lock(mm, pmd, addr, &ptl); + if (!pte) + return; arch_enter_lazy_mmu_mode(); for (; npages > 0; --npages) { pte_update(mm, addr, pte, 0, 0, 0); diff --git a/arch/powerpc/xmon/xmon.c b/arch/powerpc/xmon/xmon.c index 728d3c257e4a..69447bdf0bcf 100644 --- a/arch/powerpc/xmon/xmon.c +++ b/arch/powerpc/xmon/xmon.c @@ -3376,12 +3376,15 @@ static void show_pte(unsigned long addr) printf("pmdp @ 0x%px = 0x%016lx\n", pmdp, pmd_val(*pmdp)); ptep = pte_offset_map(pmdp, addr); - if (pte_none(*ptep)) { + if (!ptep || pte_none(*ptep)) { + if (ptep) + pte_unmap(ptep); printf("no valid PTE\n"); return; } format_pte(ptep, pte_val(*ptep)); + pte_unmap(ptep); sync(); __delay(200); -- 2.35.3