From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from ozlabs.org (ozlabs.org [103.22.144.67]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id E86311A0018 for ; Tue, 23 Jun 2015 17:47:04 +1000 (AEST) Received: from mx1.redhat.com (mx1.redhat.com [209.132.183.28]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 789EB140157 for ; Tue, 23 Jun 2015 17:47:04 +1000 (AEST) Date: Tue, 23 Jun 2015 09:46:54 +0200 From: Thomas Huth To: Nikunj A Dadhania Cc: linuxppc-dev@ozlabs.org, benh@kernel.crashing.org, aik@ozlabs.ru, dvaleev@suse.com Subject: Re: [PATCH SLOF 5/5] disk-label: make gpt detection code more robust Message-ID: <20150623094654.413b3c29@thh440s> In-Reply-To: <1434959987-8530-6-git-send-email-nikunj@linux.vnet.ibm.com> References: <1434959987-8530-1-git-send-email-nikunj@linux.vnet.ibm.com> <1434959987-8530-6-git-send-email-nikunj@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Mon, 22 Jun 2015 13:29:47 +0530 Nikunj A Dadhania wrote: > * Check for Protective MBR Magic > * Check for valid GPT Signature > * Boundary check for allocated block size before reading into the > buffer > > Signed-off-by: Nikunj A Dadhania > --- > slof/fs/packages/disk-label.fs | 21 +++++++++++++++++---- > 1 file changed, 17 insertions(+), 4 deletions(-) > > diff --git a/slof/fs/packages/disk-label.fs b/slof/fs/packages/disk-label.fs > index 821e959..d9c3a8d 100644 > --- a/slof/fs/packages/disk-label.fs > +++ b/slof/fs/packages/disk-label.fs > @@ -20,6 +20,7 @@ false VALUE debug-disk-label? > \ If we ever want to put a large kernel with initramfs from a PREP partition > \ we might need to increase this value. The default value is 65536 blocks (32MB) > d# 65536 value max-prep-partition-blocks > +d# 4096 value block-array-size > > s" disk-label" device-name > > @@ -152,8 +153,8 @@ CONSTANT /gpt-part-entry > : init-block ( -- ) > s" block-size" ['] $call-parent CATCH IF ABORT" parent has no block-size." THEN > to block-size > - d# 4096 alloc-mem > - dup d# 4096 erase > + block-array-size alloc-mem > + dup block-array-size erase > to block > debug-disk-label? IF > ." init-block: block-size=" block-size .d ." block=0x" block u. cr > @@ -175,10 +176,18 @@ CONSTANT /gpt-part-entry > block mbr>magic w@-le aa55 <> > ; > > +\ > +\ GPT Signature > +\ ("EFI PART", 45h 46h 49h 20h 50h 41h 52h 54h) > +\ > +4546492050415254 CONSTANT GPT-SIGNATURE > + > \ This word returns true if the currently loaded block has _NO_ GPT partition id > : no-gpt? ( -- true|false ) > 0 read-sector > - 1 partition>part-entry part-entry>id c@ ee <> > + 1 partition>part-entry part-entry>id c@ ee <> IF TRUE EXIT THEN > + block mbr>magic w@-le aa55 <> IF TRUE EXIT THEN > + 1 read-sector block gpt>signature x@ GPT-SIGNATURE <> The comment above the function talks about the "currently loaded block", so I'd maybe avoid to load another sector here. Maybe move this gpt>signature check to "load-from-gpt-partition" where this block gets loaded anyway? > ; > > : pc-extended-partition? ( part-entry-addr -- true|false ) > @@ -411,6 +420,10 @@ B9E5 CONSTANT GPT-BASIC-DATA-PARTITION-2 > 1 read-sector block gpt>part-entry-lba x@-le > block-size * to seek-pos > block gpt>part-entry-size l@-le to gpt-part-size > + gpt-part-size block-array-size > IF > + cr ." GPT part size exceeds buffer allocated " cr Isn't there this "addr" parameter on the stack which you might need to drop here? > + FALSE EXIT > + THEN > block gpt>num-part-entry l@-le dup 0= IF FALSE EXIT THEN > 1+ 1 ?DO > seek-pos 0 seek drop > @@ -646,7 +659,7 @@ B9E5 CONSTANT GPT-BASIC-DATA-PARTITION-2 > > : close ( -- ) > debug-disk-label? IF ." Closing disk-label: block=0x" block u. ." block-size=" block-size .d cr THEN > - block d# 4096 free-mem > + block block-array-size free-mem > ; Thomas