On Wed, 2018-06-20 at 11:14 +0200, Boris Brezillon wrote:
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>
>
> On Wed, 6 Jun 2018 12:13:29 +0200
> Joakim Tjernlund <joakim.tjernlund@xxxxxxxxxxxx> wrote:
>
> > cfi_ppb_unlock() walks all flash chips when unlocking sectors.
> > testing lock status on each chip which causes relocking of already
> > locked sectors. Test against offset to aviod this aliasing.
>
> ^ avoid
>
> As I said before, I think the current code is doing worse than just
> relocking already locked sectors. As soon as you cross a chip boundary,
> addr is set back to 0, and the (addr < offs || adr >= (ofs + len)) might
> be true while it shouldn't be (absolute offset still in the unlock
> range), which means you'll lock sectors that the caller expect to be
> unlocked.
I don't see how, the code asks for its current lock status and will reapply
those that are locked again.
>
> >
> > Fixes: 1648eaaa1575 ("mtd: cfi_cmdset_0002: Support Persistent Protection Bits (PPB) locking")
> > Cc: stable@xxxxxxxxxxxxxxx
> > Signed-off-by: Joakim Tjernlund <joakim.tjernlund@xxxxxxxxxxxx>
> > ---
> >
> > v2 - Spilt into several patches
> >
> >
> > drivers/mtd/chips/cfi_cmdset_0002.c | 2 +-
> > 1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/mtd/chips/cfi_cmdset_0002.c b/drivers/mtd/chips/cfi_cmdset_0002.c
> > index cb85cccc48c1..b6273ce83de7 100644
> > --- a/drivers/mtd/chips/cfi_cmdset_0002.c
> > +++ b/drivers/mtd/chips/cfi_cmdset_0002.c
> > @@ -2670,7 +2670,7 @@ static int __maybe_unused cfi_ppb_unlock(struct mtd_info *mtd, loff_t ofs,
> > * sectors shall be unlocked, so lets keep their locking
> > * status at "unlocked" (locked=0) for the final re-locking.
> > */
> > - if ((adr < ofs) || (adr >= (ofs + len))) {
> > + if ((offset < ofs) || (offset >= (ofs + len))) {
> > sect[sectors].chip = &cfi->chips[chipnum];
> > sect[sectors].adr = adr;
> > sect[sectors].locked = do_ppb_xxlock(
>
>
