Messages in this thread Patch in this message | | | Date | Wed, 30 Jul 2014 15:07:22 -0700 (PDT) | Subject | Re: sparc64 WARNING: at mm/mmap.c:2757 exit_mmap+0x13c/0x160() | From | David Miller <> |
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From: Meelis Roos <mroos@linux.ee> Date: Thu, 31 Jul 2014 01:02:53 +0300 (EEST)
>> Here is something I'd like you guys to test. > > Very interesting. > > [...] >> Could you guys please try this patch below? Thanks. > > CC arch/sparc/mm/init_64.o > arch/sparc/mm/init_64.c: In function 'update_mmu_cache_pmd': > arch/sparc/mm/init_64.c:2625:6: error: 'pte' may be used uninitialized in this function [-Werror=uninitialized] > > gcc 4.6.4.
I'm very disappointed that gcc-4.6.3 didn't say anything to me about this :-)
Here is a fixed patch, thanks.
diff --git a/arch/sparc/mm/init_64.c b/arch/sparc/mm/init_64.c index 16b58ff..db5ddde 100644 --- a/arch/sparc/mm/init_64.c +++ b/arch/sparc/mm/init_64.c @@ -351,6 +351,10 @@ void update_mmu_cache(struct vm_area_struct *vma, unsigned long address, pte_t * mm = vma->vm_mm; + /* Don't insert a non-valid PTE into the TSB, we'll deadlock. */ + if (!pte_accessible(mm, pte)) + return; + spin_lock_irqsave(&mm->context.lock, flags); #if defined(CONFIG_HUGETLB_PAGE) || defined(CONFIG_TRANSPARENT_HUGEPAGE) @@ -2619,6 +2623,10 @@ void update_mmu_cache_pmd(struct vm_area_struct *vma, unsigned long addr, pte = pmd_val(entry); + /* Don't insert a non-valid PMD into the TSB, we'll deadlock. */ + if (!(pte & _PAGE_VALID)) + return; + /* We are fabricating 8MB pages using 4MB real hw pages. */ pte |= (addr & (1UL << REAL_HPAGE_SHIFT));
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