| Message ID | 20180606101330.11071-3-joakim.tjernlund@infinera.com |
|---|---|
| State | Accepted |
| Delegated to: | Boris Brezillon |
| Headers | show |
| Series | [v2,1/4] mtd: cfi_cmdset_0002: Use right chip in do_ppb_xxlock() | expand |
On Wed, 6 Jun 2018 12:13:29 +0200 Joakim Tjernlund <joakim.tjernlund@infinera.com> 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. > > Fixes: 1648eaaa1575 ("mtd: cfi_cmdset_0002: Support Persistent Protection Bits (PPB) locking") > Cc: stable@vger.kernel.org > Signed-off-by: Joakim Tjernlund <joakim.tjernlund@infinera.com> > --- > > 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(
On Wed, 2018-06-20 at 11:14 +0200, Boris Brezillon wrote: > CAUTION: This email originated from outside of the organization. Do not click links or open attachments unless you recognize the sender and know the content is safe. > > > On Wed, 6 Jun 2018 12:13:29 +0200 > Joakim Tjernlund <joakim.tjernlund@infinera.com> 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@vger.kernel.org > > Signed-off-by: Joakim Tjernlund <joakim.tjernlund@infinera.com> > > --- > > > > 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( > >
On Wed, 20 Jun 2018 11:10:23 +0000 Joakim Tjernlund <Joakim.Tjernlund@infinera.com> wrote: > On Wed, 2018-06-20 at 11:14 +0200, Boris Brezillon wrote: > > CAUTION: This email originated from outside of the organization. Do not click links or open attachments unless you recognize the sender and know the content is safe. > > > > > > On Wed, 6 Jun 2018 12:13:29 +0200 > > Joakim Tjernlund <joakim.tjernlund@infinera.com> 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. After reading the commit message a second time I think I misunderstood it. I thought you were implying that the re-locking operation was harmless and the only reason for fixing the test was to avoid useless lock operations, but that's not what you wrote. Sorry for the noise.
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(
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. Fixes: 1648eaaa1575 ("mtd: cfi_cmdset_0002: Support Persistent Protection Bits (PPB) locking") Cc: stable@vger.kernel.org Signed-off-by: Joakim Tjernlund <joakim.tjernlund@infinera.com> --- v2 - Spilt into several patches drivers/mtd/chips/cfi_cmdset_0002.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)