From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.bootlin.com ([62.4.15.54]:46461 "EHLO mail.bootlin.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754646AbeFTJOm (ORCPT ); Wed, 20 Jun 2018 05:14:42 -0400 Date: Wed, 20 Jun 2018 11:14:30 +0200 From: Boris Brezillon To: Joakim Tjernlund Cc: "linux-mtd @ lists . infradead . org" , stable@vger.kernel.org Subject: Re: [PATCH v2 3/4] mtd: cfi_cmdset_0002: Avoid point less unlocking/locking Message-ID: <20180620111430.0dd2ecde@bbrezillon> In-Reply-To: <20180606101330.11071-3-joakim.tjernlund@infinera.com> References: <20180605172607.50acb34f@bbrezillon> <20180606101330.11071-1-joakim.tjernlund@infinera.com> <20180606101330.11071-3-joakim.tjernlund@infinera.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: stable-owner@vger.kernel.org List-ID: On Wed, 6 Jun 2018 12:13:29 +0200 Joakim Tjernlund 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 > --- > > 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(