Messages in this thread | | | Date | Wed, 16 Sep 2009 08:23:29 +0800 | From | Wu Fengguang <> | Subject | Re: [PATCH] hwpoison: fix uninitialized warning |
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On Wed, Sep 16, 2009 at 05:19:07AM +0800, Hugh Dickins wrote: > Fix mmotm build warning, presumably also in linux-next: > mm/memory.c: In function `do_swap_page': > mm/memory.c:2498: warning: `pte' may be used uninitialized in this function > > Signed-off-by: Hugh Dickins <hugh.dickins@tiscali.co.uk> > --- > I've only noticed this warning on one machine, the powerpc: certainly it > needs CONFIG_MIGRATION or CONFIG_MEMORY_FAILURE to see it, but I thought > I had one of those set on other machines - just musing in case it's being > masked elsewhere by some other bug... > > mm/memory.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > --- mmotm/mm/memory.c 2009-09-14 16:34:37.000000000 +0100 > +++ linux/mm/memory.c 2009-09-15 22:00:48.000000000 +0100 > @@ -2495,7 +2495,7 @@ static int do_swap_page(struct mm_struct > } else if (is_hwpoison_entry(entry)) { > ret = VM_FAULT_HWPOISON; > } else { > - print_bad_pte(vma, address, pte, NULL); > + print_bad_pte(vma, address, orig_pte, NULL); > ret = VM_FAULT_OOM; > }
The lines was introduced in this patch:
entry = pte_to_swp_entry(orig_pte); - if (is_migration_entry(entry)) { - migration_entry_wait(mm, pmd, address); + if (unlikely(non_swap_entry(entry))) { + if (is_migration_entry(entry)) { + migration_entry_wait(mm, pmd, address); + } else if (is_hwpoison_entry(entry)) { + ret = VM_FAULT_HWPOISON; + } else { + print_bad_pte(vma, address, pte, NULL); + ret = VM_FAULT_OOM; + } goto out; }
Given that currently there are only two types of non swap entries: migration/hwpoison, the last 'else' block is in fact dead code..
Thanks, Fengguang
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