Re: [OE-core] [PATCH v3] elfutils: add PACKAGECONFIG for compression algorithms
On 29/10/2019 21:46, Dan Callaghan wrote: I couldn't find anything that would ever use the bzip2 decompression in elfutils, so I had a quick look at why they even added bzip2 support in the first place. It turns out it was for reading compressed kernel images (presumably, in the elfutils tools like eu-readelf): https://sourceware.org/git/?p=elfutils.git;a=commitdiff;h=d6ccdc1a05f27bf0bb5d802ec14f879aa9fe3e98 commit d6ccdc1a05f27bf0bb5d802ec14f879aa9fe3e98 Author: Roland McGrath Date: Wed Aug 26 00:23:01 2009 -0700 libdwfl: Support Linux bzip2 kernel images for automatic decompression. And indeed on my Fedora host eu-readelf can decode ELF information from a kernel bzImage, but the eu-readelf built by Yocto's elfutils-native recipe says "not a valid ELF file" when I feed it the same bzImage. Whether that's useful or not is a different question. In our product I am planning to disable bzip2 (because we don't use the elfutils tools for anything) and enable xz (for .gnu_debugdata sections). Good digging, thanks. Lets default to bzip being off for now, and then if anyone does want this then they can just turn it on. Ross -- ___ Openembedded-core mailing list Openembedded-core@lists.openembedded.org http://lists.openembedded.org/mailman/listinfo/openembedded-core
Re: [OE-core] [PATCH v3] elfutils: add PACKAGECONFIG for compression algorithms
Excerpts from Adrian Bunk's message of 2019-10-29 22:18:21 +02:00:
> On Wed, Oct 16, 2019 at 08:44:56AM +1000, Dan Callaghan wrote:
> > Elfutils has optional support for bzip2 and xz (lzma). It uses
> > this for decompressing embedded ELF sections like the .gnu_debugdata
> > section for "mini debuginfo":
> >
> > https://sourceware.org/gdb/onlinedocs/gdb/MiniDebugInfo.html
> >...
> > +PACKAGECONFIG ??= "bzip2"
> > +PACKAGECONFIG[bzip2] = "--with-bzlib,--without-bzlib,${DEPENDS_BZIP2}"
> > +PACKAGECONFIG[xz] = "--with-lzma,--without-lzma,xz"
> >...
>
> Is any tooling actually doing this compression by default?
>
> It is a bit surprising that this has the mostly-obsolete bzip2 enabled
> by default but not the more common (and better compressing) xz.
I couldn't find anything that would ever use the bzip2 decompression in
elfutils, so I had a quick look at why they even added bzip2 support in
the first place. It turns out it was for reading compressed kernel
images (presumably, in the elfutils tools like eu-readelf):
https://sourceware.org/git/?p=elfutils.git;a=commitdiff;h=d6ccdc1a05f27bf0bb5d802ec14f879aa9fe3e98
commit d6ccdc1a05f27bf0bb5d802ec14f879aa9fe3e98
Author: Roland McGrath
Date: Wed Aug 26 00:23:01 2009 -0700
libdwfl: Support Linux bzip2 kernel images for automatic decompression.
And indeed on my Fedora host eu-readelf can decode ELF information from
a kernel bzImage, but the eu-readelf built by Yocto's elfutils-native
recipe says "not a valid ELF file" when I feed it the same bzImage.
Whether that's useful or not is a different question. In our product
I am planning to disable bzip2 (because we don't use the elfutils tools
for anything) and enable xz (for .gnu_debugdata sections).
--
Dan Callaghan
Software Engineer
Opengear
Re: [OE-core] [PATCH v3] elfutils: add PACKAGECONFIG for compression algorithms
On 29/10/2019 20:18, Adrian Bunk wrote:
On Wed, Oct 16, 2019 at 08:44:56AM +1000, Dan Callaghan wrote:
Elfutils has optional support for bzip2 and xz (lzma). It uses
this for decompressing embedded ELF sections like the .gnu_debugdata
section for "mini debuginfo":
https://sourceware.org/gdb/onlinedocs/gdb/MiniDebugInfo.html
...
+PACKAGECONFIG ??= "bzip2"
+PACKAGECONFIG[bzip2] = "--with-bzlib,--without-bzlib,${DEPENDS_BZIP2}"
+PACKAGECONFIG[xz] = "--with-lzma,--without-lzma,xz"
...
Is any tooling actually doing this compression by default?
It is a bit surprising that this has the mostly-obsolete bzip2 enabled
by default but not the more common (and better compressing) xz.
Exactly.
Ross
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Re: [OE-core] [PATCH v3] elfutils: add PACKAGECONFIG for compression algorithms
On Wed, Oct 16, 2019 at 08:44:56AM +1000, Dan Callaghan wrote:
> Elfutils has optional support for bzip2 and xz (lzma). It uses
> this for decompressing embedded ELF sections like the .gnu_debugdata
> section for "mini debuginfo":
>
> https://sourceware.org/gdb/onlinedocs/gdb/MiniDebugInfo.html
>...
> +PACKAGECONFIG ??= "bzip2"
> +PACKAGECONFIG[bzip2] = "--with-bzlib,--without-bzlib,${DEPENDS_BZIP2}"
> +PACKAGECONFIG[xz] = "--with-lzma,--without-lzma,xz"
>...
Is any tooling actually doing this compression by default?
It is a bit surprising that this has the mostly-obsolete bzip2 enabled
by default but not the more common (and better compressing) xz.
cu
Adrian
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"Only a promise," Lao Er said.
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Re: [OE-core] [PATCH v3] elfutils: add PACKAGECONFIG for compression algorithms
On 22/10/2019 13:53, Richard Purdie wrote: Breaks nativesdk-elftutils: https://autobuilder.yoctoproject.org/typhoon/#/builders/62/builds/1157 Probably need to do: DEPENDS_BZIP2 = "bzip2" DEPENDS_BZIP2_class-native = "bzip2-replacement-native" but I still think the default should be bzip2 off for -native unless someone can tell me why we need it. That would mean adding something like: PACKAGECONFIG_class-native ??= "" Proposal: lets just disable bzip2 support in elfutils by default. Ross -- ___ Openembedded-core mailing list Openembedded-core@lists.openembedded.org http://lists.openembedded.org/mailman/listinfo/openembedded-core
Re: [OE-core] [PATCH v3] elfutils: add PACKAGECONFIG for compression algorithms
On Wed, 2019-10-16 at 08:44 +1000, Dan Callaghan wrote:
> Elfutils has optional support for bzip2 and xz (lzma). It uses
> this for decompressing embedded ELF sections like the .gnu_debugdata
> section for "mini debuginfo":
>
> https://sourceware.org/gdb/onlinedocs/gdb/MiniDebugInfo.html
>
> Previously this support was unconditionally disabled but the reasons for
> disabling them seem to no longer apply. Both the target and native
> variants of elfutils can build successfully against both bzip2 and xz.
>
> Signed-off-by: Dan Callaghan
> ---
> meta/recipes-devtools/elfutils/elfutils_0.177.bb | 13 ++---
> 1 file changed, 10 insertions(+), 3 deletions(-)
>
> diff --git a/meta/recipes-devtools/elfutils/elfutils_0.177.bb
> b/meta/recipes-devtools/elfutils/elfutils_0.177.bb
> index 78c3791936..f050577c0d 100644
> --- a/meta/recipes-devtools/elfutils/elfutils_0.177.bb
> +++ b/meta/recipes-devtools/elfutils/elfutils_0.177.bb
> @@ -3,7 +3,7 @@ HOMEPAGE = "https://sourceware.org/elfutils;
> SECTION = "base"
> LICENSE = "GPLv2 & LGPLv3+ & GPLv3+"
> LIC_FILES_CHKSUM = "file://COPYING;md5=d32239bcb673463ab874e80d47fae504"
> -DEPENDS = "libtool bzip2 zlib virtual/libintl"
> +DEPENDS = "libtool zlib virtual/libintl"
> DEPENDS_append_libc-musl = " argp-standalone fts musl-obstack "
> # The Debian patches below are from:
> #
> http://ftp.de.debian.org/debian/pool/main/e/elfutils/elfutils_0.176-1.debian.tar.xz
> @@ -46,8 +46,15 @@ SRC_URI[sha256sum] =
> "fa489deccbcae7d8c920f60d85906124c1989c591196d90e0fd668e3dc
>
> inherit autotools gettext ptest
>
> -EXTRA_OECONF = "--program-prefix=eu- --without-lzma"
> -EXTRA_OECONF_append_class-native = " --without-bzlib"
> +EXTRA_OECONF = "--program-prefix=eu-"
> +
> +DEPENDS_BZIP2 = "bzip2-replacement-native"
> +DEPENDS_BZIP2_class-target = "bzip2"
> +
> +PACKAGECONFIG ??= "bzip2"
> +PACKAGECONFIG[bzip2] = "--with-bzlib,--without-bzlib,${DEPENDS_BZIP2}"
> +PACKAGECONFIG[xz] = "--with-lzma,--without-lzma,xz"
> +
> RDEPENDS_${PN}-ptest += "libasm libelf bash make coreutils ${PN}-binutils"
>
> EXTRA_OECONF_append_class-target += "--disable-tests-rpath"
Breaks nativesdk-elftutils:
https://autobuilder.yoctoproject.org/typhoon/#/builders/62/builds/1157
Probably need to do:
DEPENDS_BZIP2 = "bzip2"
DEPENDS_BZIP2_class-native = "bzip2-replacement-native"
but I still think the default should be bzip2 off for -native unless
someone can tell me why we need it. That would mean adding something
like:
PACKAGECONFIG_class-native ??= ""
Cheers,
Richard
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