> Date: Mon, 22 Jul 2024 00:19:28 +0200
> From: Jeremie Courreges-Anglas <j...@wxcvbn.org>
>
> On Sat, Jul 20, 2024 at 10:50:30AM +0200, Landry Breuil wrote:
> > Le Fri, Jul 19, 2024 at 10:45:18AM +0200, Landry Breuil a écrit :
> > > Le Fri, Jul 19, 2024 at 08:49:54AM +0200, Peter Hessler a écrit :
> > > > On 2024 Jul 18 (Thu) at 21:35:47 -0600 (-0600), phess...@openbsd.org
> > > > wrote:
> > > > :critical path missing pkgs:
> > > > http://build-failures.rhaalovely.net/aarch64/2024-07-16/summary.log
> > > >
> > > > :http://build-failures.rhaalovely.net/aarch64/2024-07-16/mail/mozilla-thunderbird.log
> > > > :http://build-failures.rhaalovely.net/aarch64/2024-07-16/www/firefox-esr.log
> > > > :http://build-failures.rhaalovely.net/aarch64/2024-07-16/www/tor-browser/browser.log
> > > > :http://build-failures.rhaalovely.net/aarch64/2024-07-16/x11/qt5/qtwebengine.log
> > > >
> > > > the above 4 ports fail related to hwcap in the same way:
> > > >
> > > > /usr/obj/ports/firefox-esr-115.13.0/firefox-115.13.0/gfx/skia/skia/src/core/SkCpu.cpp:84:27:
> > > > error: use of undeclared identifier 'getauxval'
> > > > uint32_t hwcaps = getauxval(AT_HWCAP);
> > >
> > > https://searchfox.org/mozilla-esr115/source/gfx/skia/skia/src/core/SkCpu.cpp#76
> > > for the surrounding code, i guess it now finds a sys/auxv.h header ?
>
> That would make sense. Looking at the www/mozilla-firefox copy of
> skia, this chunk of code appears to have disappeared from SkCpu.cpp.
>
>
> https://github.com/google/skia/commit/571b4cf2e35930f6744181b73b72939ab236f3ea
>
> The addition of elf_aux_info(3) was intended to make it easier for
> external software to use optimizations, but maybe for these ports it
> would be just easier to patch out feature detection? ;)
>
> > the below patch goes past this build failure, but libipcclientcerts.so
> > doesn't link with lld:
> >
> > rm -f libipcclientcerts.so.10.0
> >
> >
> > /usr/obj/ports/firefox-esr-115.13.0/bin/cc -std=gnu99 -U_FORTIFY_SOURCE
> > -D_FORTIFY_SOURCE=2 -fstack-protector-strong -Wno-backend-plugin -O2 -pipe
> > -g -fPIC -ffunction-sections -fdata-sections -fno-math-errno -pthread
> > -pipe -gdwarf-4 -O2 -pipe -g -fomit-frame-pointer -funwind-tables
> > -fprofile-use=/usr/obj/ports/firefox-esr-115.13.0/merged.profdata
> > -Wno-error=backend-plugin -shared -fPIC -Wl,--gc-sections
> > -Wl,-h,libipcclientcerts.so.10.0 -o libipcclientcerts.so.10.0 stub.o
> > -flto=thin -Wl,-plugin-opt=-import-instr-limit=10
> > -Wl,-plugin-opt=-import-hot-multiplier=30 -pthread -Wl,--threads=8
> > -Wl,-z,noexecstack -Wl,-z,text -Wl,-z,relro -Wl,-z,nocopyreloc
> > -Wl,-Bsymbolic-functions -Wl,--build-id=sha1 -fstack-protector-strong
> > -Wl,-rpath-link,/usr/obj/ports/firefox-esr-115.13.0/build-aarch64/dist/bin
> > -Wl,-rpath-link,/usr/local/lib -Wl,-rpath-link,/usr/X11R6/lib
> > /usr/obj/ports/firefox-esr-115.13.0/build-aarch64/aarch64-unknown-openbsd/release/libipcclientcerts_static.a
> > -Wl,--version-script,libipcclientcerts.so.10.0.symbols
> > /usr/obj/ports/firefox-esr-115.13.0/build-aarch64/_virtualenvs/build/bin/python
> > -m mozbuild.action.check_binary --target libipcclientcerts.so.10.0
> > BUILDTASK {"argv":
> > ["/usr/obj/ports/firefox-esr-115.13.0/firefox-115.13.0/python/mozbuild/mozbuild/action/check_binary.py",
> > "--target", "libipcclientcerts.so.10.0"], "start": 12452.418140014,
> > "end": 12452.543060385, "context": null}
> > chmod +x libipcclientcerts.so.10.0
> > ../../../../../config/nsinstall -R -m 644 'libipcclientcerts.so.10.0'
> > '../../../../../dist/bin'
> > gmake[3]: Leaving directory
> > '/usr/obj/ports/firefox-esr-115.13.0/build-aarch64/security/manager/ssl/ipcclientcerts/dynamic-library'
> >
> > ld.lld: error: undefined hidden symbol: elf_aux_info
> > >>> referenced by SkCpu.cpp:85
> > >>> (/usr/obj/ports/firefox-esr-115.13.0/firefox-115.13.0/gfx/skia/skia/src/core/SkCpu.cpp:85)
> > >>>
> > >>> lto.tmp:(SkCpu::CacheRuntimeFeatures())
> > clang-16: error: linker command failed with exit code 1 (use -v to see
> > invocation) i
> >
> > i dunno which of the -Wl flags triggers this, but the elf_aux_info symbol is
> > present as a weak symbol in libc.so.100.2, but i see that it doesnt
> > explicitely
> > link with -lc - though maybe it shouldnt be required.
>
> I think I have already seen this "global vs hidden" mismatch for weak
> symbols previously, but I don't remember the specifics. Looking at
> the arm64 base sets, llvm-readelf -Wa libc.so.100.2 shows
> elf_aux_info(3) as a weak symbol with default (not hidden) visibility:
>
> 1410: 000000000008c80c 224 FUNC WEAK DEFAULT 12 elf_aux_info
>
> That looks correct to me.
Indeed. This is no different from other exported symbols in libc that
aren't part of standard ISO C.
> I suspect the error message means there's another elf_aux_info()
> definition in your build, but with hidden visibility; but I couldn't
> find one in the firefox-esr tarball and I could very well be mistaken.
Where would that come from?
In general I'd say shared objects should always be linked against
libc. But Theo will probably never agree with me. However, in this
case the suggestion from jca@ to follow "upstream" and drop the
feature detection code on arm64 is probably the best approach.
> cc'ing the usual ELFs, maybe they'll have some clues.
>
> > $cat patches/patch-gfx_skia_skia_src_core_SkCpu_cpp
> > Fix build with auxv.h addition
>
> See below,
>
> > Index: gfx/skia/skia/src/core/SkCpu.cpp
> > --- gfx/skia/skia/src/core/SkCpu.cpp.orig
> > +++ gfx/skia/skia/src/core/SkCpu.cpp
> > @@ -81,7 +81,8 @@
> > kHWCAP_ASIMDHP = (1<<10);
> >
> > uint32_t features = 0;
> > - uint32_t hwcaps = getauxval(AT_HWCAP);
> > + uint32_t hwcaps = 0;
>
> As pointed out by naddy, 'hwcaps' should be an unsigned long.
>
> > + elf_aux_info(AT_HWCAP, &hwcaps, sizeof(hwcaps));
>
> naddy also pointed out the lack of error checking; I think you can
> rely on the fact that elf_aux_info(3) won't touch *hwcaps if it fails.
> I doubt that you'll have to upstream that code anyway...
>
> > if (hwcaps & kHWCAP_CRC32 ) { features |= SkCpu::CRC32; }
> > if (hwcaps & kHWCAP_ASIMDHP) { features |= SkCpu::ASIMDHP; }
> >
> > >
> > > Landry
> > >
> >
>
> --
> jca
>
