From: Thomas Huth <thuth@redhat•com>
To: Nikunj A Dadhania <nikunj@linux•vnet.ibm.com>
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
Date: Tue, 23 Jun 2015 09:46:54 +0200 [thread overview]
Message-ID: <20150623094654.413b3c29@thh440s> (raw)
In-Reply-To: <1434959987-8530-6-git-send-email-nikunj@linux.vnet.ibm.com>
On Mon, 22 Jun 2015 13:29:47 +0530
Nikunj A Dadhania <nikunj@linux•vnet.ibm.com> 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 <nikunj@linux•vnet.ibm.com>
> ---
> 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
next prev parent reply other threads:[~2015-06-23 7:47 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-06-22 7:59 [PATCH SLOF 0/5] GPT fixes/cleanup and LVM support with FAT Nikunj A Dadhania
2015-06-22 7:59 ` [PATCH SLOF 1/5] disk-label: simplify gpt-prep-partition? routine Nikunj A Dadhania
2015-06-23 7:08 ` Thomas Huth
2015-06-22 7:59 ` [PATCH SLOF 2/5] introduce 8-byte LE helpers Nikunj A Dadhania
2015-06-23 7:09 ` Thomas Huth
2015-06-22 7:59 ` [PATCH SLOF 3/5] disk-label: introduce helper to check fat filesystem Nikunj A Dadhania
2015-06-22 19:35 ` Segher Boessenkool
2015-06-23 6:06 ` Nikunj A Dadhania
2015-06-22 7:59 ` [PATCH SLOF 4/5] disk-label: add support for booting from GPT FAT partition Nikunj A Dadhania
2015-06-23 7:34 ` Thomas Huth
2015-06-24 2:10 ` Segher Boessenkool
2015-06-24 5:29 ` Nikunj A Dadhania
2015-06-24 5:33 ` Nikunj A Dadhania
2015-06-22 7:59 ` [PATCH SLOF 5/5] disk-label: make gpt detection code more robust Nikunj A Dadhania
2015-06-23 7:46 ` Thomas Huth [this message]
2015-06-24 5:34 ` Nikunj A Dadhania
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