[PATCH] scripts: make extract-vmlinux support armel/armhf
From: linux@armlinux.org.uk (Russell King - ARM Linux)
Date: 2017-08-31 15:49:41
Also in:
linux-kbuild
On Fri, Sep 01, 2017 at 12:36:31AM +0900, Roger Shimizu wrote:
vmlinux/zImage on armel/armhf seems not an ELF, so update the script
scripts/extract-vmlinux to support such case.
This fix is tested on Debian amd64, armel, and armhf platform, with
Debian kernels.
Fixes: 09d481270d44 ("scripts: add extract-vmlinux")
Cc: Corentin Chary <redacted>
Cc: Michal Marek <redacted>
Cc: Masahiro Yamada <redacted>
Cc: Russell King <redacted>
Cc: linux-arm-kernel at lists.infradead.org
Cc: linux-kbuild at vger.kernel.org
Signed-off-by: Roger Shimizu <redacted>
---
Dear Michal, Masahiro-san, and Russell,
I posted this patch before [0] but didn't get positive response.
Recently when I trace a Debian kernel issue, I still find this patch
useful to locate the root cause [1].
Besides, it's a well known bug confuses other developers [2][3].
So I decide to submit the patch again.
[0]: https://patchwork.kernel.org/patch/8120831/
[1]: https://bugs.debian.org/870185#50
[2]: https://bugs.launchpad.net/linaro-ubuntu/+bug/1050453
[3]: https://bugs.linaro.org/show_bug.cgi?id=461
Please kindly help to review. Thank you!I don't think this makes sense. This script claims to extract a "vmlinux" from a compressed kernel image. "vmlinux" is normally the term of the ELF object, and indeed as the script currently stands, it always guarantees to output an ELF file. However, ARM zImage does not store a compressed ELF object, it stores a compressed binary image of the executable in memory, so what you get out of this script is not an ELF file, but the binary image (iow, what arch/arm/boot/Image is.) What's the use case - what are you using the output of this script with?
quoted hunk ↗ jump to hunk
diff --git a/scripts/extract-vmlinux b/scripts/extract-vmlinux index 5061abcc2540..0c72ecd24969 100755 --- a/scripts/extract-vmlinux +++ b/scripts/extract-vmlinux@@ -6,6 +6,7 @@ # (c) 2009,2010 Dick Streefland <dick@streefland.net> # # (c) 2011 Corentin Chary <corentin.chary@gmail.com> +# (c) 2016 Roger Shimizu <rogershimizu@gmail.com> # # Licensed under the GNU General Public License, version 2 (GPLv2). # ----------------------------------------------------------------------@@ -15,7 +16,14 @@ check_vmlinux() # Use readelf to check if it's a valid ELF # TODO: find a better to way to check that it's really vmlinux # and not just an elf - readelf -h $1 > /dev/null 2>&1 || return 1 + case "$2" in + 0|"") + readelf -h $1 > /dev/null 2>&1 || return 1 + ;; + 1) + # For ARCH like armel/armhf, vmlinux is not ELF, so we skip the check + ;; + esac
Right, so passing the second argument as 1 bypasses the "is it ELF" check.
quoted hunk ↗ jump to hunk
@@ -31,7 +39,7 @@ try_decompress() do pos=${pos%%:*} tail -c+$pos "$img" | $3 > $tmp 2> /dev/null - check_vmlinux $tmp + test $? -eq 0 && check_vmlinux $tmp 1
and here you always pass '1', thereby bypassing the ELF check for every architecture. What if some architecture stores another compressed object in the same compressed image? I suspect the check is there to ensure that it works on architectures where the compressed kernel image contains other compressed objects. -- RMK's Patch system: http://www.armlinux.org.uk/developer/patches/ FTTC broadband for 0.8mile line in suburbia: sync at 8.8Mbps down 630kbps up According to speedtest.net: 8.21Mbps down 510kbps up