On 05/14/2019 03:56 AM, Kani, Toshi wrote: > On Thu, 2019-05-09 at 10:16 +0530, Anshuman Khandual wrote: >> Virtual address alignment is essential in ensuring correct clearing for all >> intermediate level pgtable entries and freeing associated pgtable pages. An >> unaligned address can end up randomly freeing pgtable page that potentially >> still contains valid mappings. Hence also check it's alignment along with >> existing phys_addr check. >> >> Signed-off-by: Anshuman Khandual <anshuman.khandual@xxxxxxx> >> Cc: Toshi Kani <toshi.kani@xxxxxxx> >> Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> >> Cc: Will Deacon <will.deacon@xxxxxxx> >> Cc: Chintan Pandya <cpandya@xxxxxxxxxxxxxx> >> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> >> Cc: Catalin Marinas <catalin.marinas@xxxxxxx> >> --- >> lib/ioremap.c | 6 ++++++ >> 1 file changed, 6 insertions(+) >> >> diff --git a/lib/ioremap.c b/lib/ioremap.c >> index 063213685563..8b5c8dda857d 100644 >> --- a/lib/ioremap.c >> +++ b/lib/ioremap.c >> @@ -86,6 +86,9 @@ static int ioremap_try_huge_pmd(pmd_t *pmd, unsigned long addr, >> if ((end - addr) != PMD_SIZE) >> return 0; >> >> + if (!IS_ALIGNED(addr, PMD_SIZE)) >> + return 0; >> + >> if (!IS_ALIGNED(phys_addr, PMD_SIZE)) >> return 0; >> >> @@ -126,6 +129,9 @@ static int ioremap_try_huge_pud(pud_t *pud, unsigned long addr, >> if ((end - addr) != PUD_SIZE) >> return 0; >> >> + if (!IS_ALIGNED(addr, PUD_SIZE)) >> + return 0; >> + >> if (!IS_ALIGNED(phys_addr, PUD_SIZE)) >> return 0; > > Not sure if we have such case today, but I agree that it is prudent to > have such checks. Is there any reason not to add this check to p4d for > consistency? No, will add it.
