From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marek Vasut Date: Wed, 6 May 2020 17:52:45 +0200 Subject: [PATCH V2] mkimage: fit: Do not tail-pad fitImage with external data In-Reply-To: References: <20200505175022.GW12564@bill-the-cat> <1073087038ce37a09715bcb5054c7931@walle.cc> <20200506134857.GE12564@bill-the-cat> <20200506142754.GH12564@bill-the-cat> <04369d83-daef-03c3-7a9e-7a6c83f9a5a3@denx.de> <20200506143724.GI12564@bill-the-cat> Message-ID: <04cb1a3b-ec71-9ce1-f0cd-9d4ddae57010@denx.de> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de On 5/6/20 5:43 PM, Alex Kiernan wrote: > On Wed, May 6, 2020 at 3:41 PM Marek Vasut wrote: >> >> On 5/6/20 4:37 PM, Tom Rini wrote: >>> On Wed, May 06, 2020 at 04:33:37PM +0200, Marek Vasut wrote: >>>> On 5/6/20 4:27 PM, Tom Rini wrote: >>>>> On Wed, May 06, 2020 at 04:17:35PM +0200, Marek Vasut wrote: >>>>>> On 5/6/20 3:48 PM, Tom Rini wrote: >>>>>>> On Tue, May 05, 2020 at 11:17:19PM +0200, Michael Walle wrote: >>>>>>>> Hi all, >>>>>>>> >>>>>>>> Am 2020-05-05 20:41, schrieb Simon Glass: >>>>>>>>> Hi Tom, >>>>>>>>> >>>>>>>>> On Tue, 5 May 2020 at 11:50, Tom Rini wrote: >>>>>>>>>> >>>>>>>>>> On Tue, May 05, 2020 at 06:39:58PM +0200, Marek Vasut wrote: >>>>>>>>>>> On 5/5/20 6:37 PM, Alex Kiernan wrote: >>>>>>>>>>>> On Tue, May 5, 2020 at 2:28 PM Marek Vasut wrote: >>>>>>>>>>>>> >>>>>>>>>>>>> On 5/5/20 3:22 PM, Alex Kiernan wrote: >>>>>>>>>>>>>> On Mon, May 4, 2020 at 12:28 PM Tom Rini wrote: >>>>>>>>>>>>>>> >>>>>>>>>>>>>>> On Fri, May 01, 2020 at 05:40:25PM +0200, Marek Vasut wrote: >>>>>>>>>>>>>>> >>>>>>>>>>>>>>>> There is no reason to tail-pad fitImage with external data to 4-bytes, >>>>>>>>>>>>>>>> while fitImage without external data does not have any such padding and >>>>>>>>>>>>>>>> is often unaligned. DT spec also does not mandate any such padding. >>>>>>>>>>>>>>>> >>>>>>>>>>>>>>>> Moreover, the tail-pad fills the last few bytes with uninitialized data, >>>>>>>>>>>>>>>> which could lead to a potential information leak. >>>>>>>>>>>>>>>> >>>>>>>>>>>>>>>> $ echo -n xy > /tmp/data ; \ >>>>>>>>>>>>>>>> ./tools/mkimage -E -f auto -d /tmp/data /tmp/fitImage ; \ >>>>>>>>>>>>>>>> hexdump -vC /tmp/fitImage | tail -n 3 >>>>>>>>>>>>>>>> >>>>>>>>>>>>>>>> before: >>>>>>>>>>>>>>>> 00000260 61 2d 6f 66 66 73 65 74 00 64 61 74 61 2d 73 69 |a-offset.data-si| >>>>>>>>>>>>>>>> 00000270 7a 65 00 00 78 79 64 64 |ze..xydd| >>>>>>>>>>>>>>>> ^^ ^^ ^^ >>>>>>>>>>>>>>>> after: >>>>>>>>>>>>>>>> 00000260 61 2d 6f 66 66 73 65 74 00 64 61 74 61 2d 73 69 |a-offset.data-si| >>>>>>>>>>>>>>>> 00000270 7a 65 00 78 79 |ze.xy| >>>>>>>>>>>>>>>> >>>>>>>>>>>>>>>> Signed-off-by: Marek Vasut >>>>>>>>>>>>>>>> Reviewed-by: Simon Glass >>>>>>>>>>>>>>>> Cc: Heinrich Schuchardt >>>>>>>>>>>>>>>> Cc: Tom Rini >>>>>>>>>>>>>>> >>>>>>>>>>>>>>> Applied to u-boot/master, thanks! >>>>>>>>>>>>>>> >>>>>>>>>>>>>> >>>>>>>>>>>>>> This breaks booting on my board (am3352, eMMC boot, FIT u-boot, >>>>>>>>>>>>>> CONFIG_SPL_LOAD_FIT). Not got any useful diagnostics - if I boot it >>>>>>>>>>>>>> from eMMC I get nothing at all on the console, if I boot over ymodem >>>>>>>>>>>>>> it stalls at 420k, before continuing to 460k. My guess is there's some >>>>>>>>>>>>>> error going to the console at the 420k mark, but obviously it's lost >>>>>>>>>>>>>> in the ymodem... I have two DTBs in the FIT image, 420k would about >>>>>>>>>>>>>> align to the point between them. >>>>>>>>>>>>> >>>>>>>>>>>>> My bet would be on some padding / unaligned access problem that this >>>>>>>>>>>>> patch uncovered. Can you take a look ? >>>>>>>>>>>> >>>>>>>>>>>> Seems plausible. With this change my external data starts at 0x483 and >>>>>>>>>>>> everything after it is non-aligned: >>>>>>>>>>> >>>>>>>>>>> Should the beginning of external data be aligned ? >>>>>>>>>> >>>>>>>>>> If in U-Boot we revert e8c2d25845c72c7202a628a97d45e31beea40668 does >>>>>>>>>> the >>>>>>>>>> problem go away? If so, that's not a fix outright, it means we need >>>>>>>>>> to >>>>>>>>>> dig back in to the libfdt thread and find the "make this work without >>>>>>>>>> killing performance everywhere all the time" option. >>>>>>>>> >>>>>>>>> If it is a device tree, it must be 32-bit aligned. >>>>>>>> >>>>>>>> This commit actually breaks my board too (which I was just about to send >>>>>>>> upstream, but realized it was broken). >>>>>>>> >>>>>>>> Said board uses SPL and main U-Boot. SPL runs fine and main u-boot doesn't >>>>>>>> output anything. The only difference which I found is that fit-dtb.blob is >>>>>>>> 2 bytes shorter. And the content is shifted by one byte although >>>>>>>> data-offset is the same. Strange. In the non-working case, the inner >>>>>>>> FDT magic isn't 4 byte aligned. >>>>>>>> >>>>>>>> You can find the two fit-dtb.blobs here: >>>>>>>> >>>>>>>> https://walle.cc/u-boot/fit-dtb.blob.working >>>>>>>> https://walle.cc/u-boot/fit-dtb.blob.non-working >>>>>>>> >>>>>>>> >>>>>>>> Reverting e8c2d25845c72c7202a628a97d45e31beea40668 doesn't help (I might >>>>>>>> reverted it the wrong way, there is actually a conflict). >>>>>>>> >>>>>>>> I'll dig deeper into that tomorrow, but maybe you have some pointers where >>>>>>>> to look. >>>>>>>> >>>>>>>> For reference you can find the current patch here: >>>>>>>> https://github.com/mwalle/u-boot/tree/sl28-upstream >>>>>>> >>>>>>> I think we have a few things to fix here. Marek's patch is breaking >>>>>>> things and needs to be reverted. But it's showing a few underlying >>>>>>> problems that need to be fixed too: >>>>>>> - fit_extract_data() needs to use calloc() not malloc() so that we don't >>>>>>> leak random data. >>>>>>> - We need to 8-byte alignment on the external data. That's the >>>>>>> requirement for Linux for device trees on both 32 and 64bit arm. >>>>>>> Atish, does RISC-V require more than that? I don't see it in Linux's >>>>>>> Documentation/riscv/boot-image-header.rst (and there's no booting.rst >>>>>>> file like arm/arm64). >>>>>> >>>>>> Why 8-byte alignment ? The external data are copied into the target >>>>>> location, so why do they need to be padded in any way? >>>>> >>>>> The start of the external data needs the alignment, to be clearer. >>>> >>>> Why ? >>> >>> Given that things which end up in external data have alignment >>> requirements, we need to align and meet those requirements. And I noted >>> why 8 above. >> >> If you end up with external data, then you need to move those blobs into >> their target location anyway. That's what you specify in the load = <> >> property in the .its . >> > > Just reading common/spl/spl_fit.c, I think that'll try and parse in > situ, rather than relocating it? And is that correct or is that the same problem as we have on arm64 with fitImage and fdt_high=-1 ? I think it's the later.