| Message ID | 1366382971-12682-1-git-send-email-steve.capper@linaro.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Fri, Apr 19, 2013 at 03:49:31PM +0100, Steve Capper wrote: > show_pte makes use of the *_none_or_clear_bad style functions. If a > pgd, pud or pmd is identified as being bad, it will then be cleared. > > As show_pte appears to be called from either the user or kernel > fault handlers this side effect can lead to unpredictable behaviour; > especially as TLB entries are not invalidated. > > This patch removes the page table sanitisation from show_pte. If a > bad pgd, pud or pmd is encountered it is left unmodified. > > Signed-off-by: Steve Capper <steve.capper@linaro.org> Thanks. Applied.
On Thu, Apr 25, 2013 at 02:51:06PM +0100, Catalin Marinas wrote: > Thanks. Applied. > > -- > Catalin Cheers!
diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c index afadae6..5263817 100644 --- a/arch/arm64/mm/fault.c +++ b/arch/arm64/mm/fault.c @@ -57,16 +57,16 @@ void show_pte(struct mm_struct *mm, unsigned long addr) pmd_t *pmd; pte_t *pte; - if (pgd_none_or_clear_bad(pgd)) + if (pgd_none(*pgd) || pgd_bad(*pgd)) break; pud = pud_offset(pgd, addr); - if (pud_none_or_clear_bad(pud)) + if (pud_none(*pud) || pud_bad(*pud)) break; pmd = pmd_offset(pud, addr); printk(", *pmd=%016llx", pmd_val(*pmd)); - if (pmd_none_or_clear_bad(pmd)) + if (pmd_none(*pmd) || pmd_bad(*pmd)) break; pte = pte_offset_map(pmd, addr);
show_pte makes use of the *_none_or_clear_bad style functions. If a pgd, pud or pmd is identified as being bad, it will then be cleared. As show_pte appears to be called from either the user or kernel fault handlers this side effect can lead to unpredictable behaviour; especially as TLB entries are not invalidated. This patch removes the page table sanitisation from show_pte. If a bad pgd, pud or pmd is encountered it is left unmodified. Signed-off-by: Steve Capper <steve.capper@linaro.org> --- arch/arm64/mm/fault.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)