On Sat, Nov 30, 2019 at 11:49 PM Waldek Kozaczuk <[email protected]> wrote:
> We the extra debug printouts the crash looks like this: > > ELF [tid:42, /usr/lib/libgcc_s.so.1]: Instantiated > ELF [tid:42, /usr/lib/libgcc_s.so.1]: The base set to: 0x00000000000a7000 > and end: 0x00000000000c0450 > ELF [tid:42, /usr/lib/libgcc_s.so.1]: Loading segments > ELF [tid:42, /usr/lib/libgcc_s.so.1]: Loaded and mapped PT_LOAD segment > at: 0x00000000000a7000 of size: 0x3000 > ELF [tid:42, /usr/lib/libgcc_s.so.1]: Loaded and mapped PT_LOAD segment > at: 0x00000000000aa000 of size: 0x11000 > ELF [tid:42, /usr/lib/libgcc_s.so.1]: Loaded and mapped PT_LOAD segment > at: 0x00000000000bb000 of size: 0x4000 > ELF [tid:42, /usr/lib/libgcc_s.so.1]: Loaded and mapped PT_LOAD segment > at: 0x00000000000bf000 of size: 0x2000 > ELF [tid:42, /usr/lib/libgcc_s.so.1]: Loading DT_NEEDED object: libc.so.6 > /usr/lib/libgcc_s.so.1: ignoring missing symbol __cpu_indicator_init > /usr/lib/libgcc_s.so.1: ignoring missing symbol __cpu_model > ELF [tid:42, /usr/lib/libgcc_s.so.1]: Relocated 10 symbols in DT_RELA > ELF [tid:42, /usr/lib/libgcc_s.so.1]: Relocated 45 PLT symbols in DT_JMPREL > ELF [tid:42, /usr/lib/libgcc_s.so.1]: versioned symbol table > ELF [tid:42, /java_isolated.so]: Loading DT_NEEDED object: libc.so.6 > ELF [tid:42, /java_isolated.so]: Relocated 469 symbols in DT_RELA > ELF [tid:42, /java_isolated.so]: Relocated 246 PLT symbols in DT_JMPREL > ELF [tid:42, /java_isolated.so]: versioned symbol table > ELF [tid:253, /usr/lib/libgcc_s.so.1]: Executing DT_INIT function > ELF [tid:253, /usr/lib/libgcc_s.so.1]: Finished executing DT_INIT function > ELF [tid:253, /usr/lib/libgcc_s.so.1]: Executing 2 DT_INIT_ARRAYSZ > functions > trying to execute or access missing symbol > [backtrace] > 0x00000000403aeb19 <page_fault+297> > 0x00000000403ad8d6 <???+1077598422> > 0x00000000403609fa <elf::program::init_library(int, char**)+362> > 0x0000000040226237 <osv::application::main()+71> > 0x000000004044406c <???+1078214764> > 0x00000000404782b9 <???+1078428345> > 0x000000004040f29b <thread_main_c+43> > 0x00000000403ae852 <???+1077602386> > > It looks like one of the 2 functions in DT_INIT_ARRAYSZ references one of > the missing symbols (per versym). Probably __cpu_indicator_init. > > So I wonder that instead of skipping deprecated symbols, we should tweak > the versioning logic to make it find symbols IF referenced by the object > itself. Other part of the Drepper's text - > https://www.akkadia.org/drepper/symbol-versioning - seems to suggest that: > > "vna_other > > Contains version index unique for the file which is used in the > version symbol table. If the highest bit (bit 15) is set this > is a hidden symbol which cannot be referenced *from outside the > object*." > > > Sounds right. In general, the phrase "hidden symbol" usually means that it is hidden from other objects - not that it is completely unusable. > > On Saturday, November 30, 2019 at 1:16:46 PM UTC-5, Waldek Kozaczuk wrote: >> >> Or is the issue that given that __cpu_indicator_init is a constructor >> function that is in symver and deprecated > 4.8 we should also skip >> calling deprecated INIT functions ? >> >> On Sat, Nov 30, 2019 at 00:34 Waldek Kozaczuk <[email protected]> >> wrote: >> >>> Here is the change made to libgcc.so 4 years ago that seems to be >>> causing this problem - >>> https://github.com/gcc-mirror/gcc/commit/4b5fb32aba30762e0d8c9e75d1b46b47bee5eeb4 >>> . >>> >>> These 2 missing (hidden with versioning) are present in libgcc.a: >>> readelf -s /usr/lib/gcc/x86_64-linux-gnu/9/libgcc.a | grep >>> __cpu_indicator_init >>> 13: 0000000000000290 905 FUNC GLOBAL HIDDEN 4 >>> __cpu_indicator_init >>> >>> We stopped linking libgcc.a as whole-archive year ago but even if we >>> still did it would not help us given this symbol is hidden. >>> >>> I wonder how we should solve it. >>> >>> >>> On Thursday, November 28, 2019 at 3:18:48 PM UTC-5, Waldek Kozaczuk >>> wrote: >>>> >>>> This is related to https://github.com/cloudius-systems/osv/issues/743. >>>> >>>> I have been trying to eliminate ancient libgcc_s.so from >>>> usr.manifest.skel and replace it with the version from host. When I do that >>>> most (C++ only?) apps fail like so: >>>> >>>> Cmdline: /java_isolated.so -cp /tests/java/tests.jar >>>> io.osv.TestDomainPermissions >>>> /usr/lib/libgcc_s.so.1: ignoring missing symbol __cpu_indicator_init >>>> /usr/lib/libgcc_s.so.1: ignoring missing symbol __cpu_model >>>> trying to execute or access missing symbol >>>> [backtrace] >>>> 0x000000004039d6ab <page_fault+267> >>>> 0x000000004039c486 <???+1077527686> >>>> 0x00000000403528ca <elf::program::init_library(int, char**)+362> >>>> 0x0000000040223cdd <osv::application::main()+61> >>>> 0x000000004042deb8 <???+1078124216> >>>> 0x000000004045fdb5 <???+1078328757> >>>> 0x00000000403f9ce7 <thread_main_c+39> >>>> 0x000000004039d402 <???+1077531650> >>>> >>>> I somehow discovered it has to do with versioning. So when I undo my >>>> commit that fixed libnuma (see >>>> https://github.com/cloudius-systems/osv/commit/ed1eed7a567ec17138c65f0a5628c2311603c712 >>>> ). >>>> >>>> So if I manually undo these changes the error disappears. It is >>>> obviously related to these warnings: >>>> /usr/lib/libgcc_s.so.1: ignoring missing symbol __cpu_indicator_init >>>> /usr/lib/libgcc_s.so.1: ignoring missing symbol __cpu_model >>>> >>>> What is actually going on? And what is the right fix? >>>> >>>> I found couple of the things that might be related: >>>> >>>> https://bugzilla.redhat.com/show_bug.cgi?id=1688766 >>>> >>>> http://cgit.openembedded.org/openembedded-core/tree/meta/recipes-devtools/gcc/gcc-9.2/0032-libgcc_s-Use-alias-for-__cpu_indicator_init-instead-.patch?h=master >>>> >>>> Waldek >>>> >>>> >>>> >>>> >>>> -- >>> You received this message because you are subscribed to a topic in the >>> Google Groups "OSv Development" group. >>> To unsubscribe from this topic, visit >>> https://groups.google.com/d/topic/osv-dev/HZHzeG_5IqM/unsubscribe. >>> To unsubscribe from this group and all its topics, send an email to >>> [email protected]. >>> To view this discussion on the web visit >>> https://groups.google.com/d/msgid/osv-dev/e5b7c460-b7d5-438f-9001-5546f65c4894%40googlegroups.com >>> <https://groups.google.com/d/msgid/osv-dev/e5b7c460-b7d5-438f-9001-5546f65c4894%40googlegroups.com?utm_medium=email&utm_source=footer> >>> . >>> >> -- > You received this message because you are subscribed to the Google Groups > "OSv Development" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To view this discussion on the web visit > https://groups.google.com/d/msgid/osv-dev/ca3133df-a5bf-42bb-84da-b1963aef3d3d%40googlegroups.com > <https://groups.google.com/d/msgid/osv-dev/ca3133df-a5bf-42bb-84da-b1963aef3d3d%40googlegroups.com?utm_medium=email&utm_source=footer> > . > -- You received this message because you are subscribed to the Google Groups "OSv Development" group. 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