[PATCH] D41215: Fix crash on invalid

[Peter Collingbourne via llvm-commits]

On Thu, Dec 14, 2017 at 1:29 PM, Rui Ueyama <ruiu at google.com> wrote:

> On Thu, Dec 14, 2017 at 1:22 PM, Peter Collingbourne <peter at pcc.me.uk>
> wrote:
>
>> On Thu, Dec 14, 2017 at 10:27 AM, Rafael Avila de Espindola via
>> llvm-commits <llvm-commits at lists.llvm.org> wrote:
>>
>>> Is libwidevinecdm.so available somewhere?
>>>
>>
>> If you have a recent version of Chrome installed on your machine, you
>> should be able to find a copy in your installation directory.
>>
>> We can try to make it a warning, but what is the correct thing to do
>>> about _ZN8tcmalloc11ThreadCache17threadlocal_heap_E? Should we skip it?
>>> Handle it as if it was global?
>>>
>>
>> I think we should skip it. It looks like the symbol itself is supposed to
>> be local.
>> https://cs.chromium.org/chromium/src/third_party/tcmalloc/ve
>> ndor/src/thread_cache.h?q=threadlocal_heap&sq=package:chromium&l=255
>>
>
> Is it? It's a static member of some class and not a file local symbol.
>

Oh right, that wouldn't have caused the symbol to become STB_LOCAL then. It
could have been made local as a result of the library being built with
-fvisibility=hidden though. It could then have ended up in .dynsym as a
result of one of the bugs mentioned here:
https://sourceware.org/ml/binutils/2016-05/msg00076.html

Peter

>
>
>> Peter
>>
>>
>>> Cheers,
>>> Rafael
>>>
>>> Hans Wennborg via Phabricator <reviews at reviews.llvm.org> writes:
>>>
>>> > hans added a comment.
>>> >
>>> > This fixes the assert, now we error on it, which breaks our build all
>>> the same. It's a pre-built .so, which I'm not sure exactly where it comes
>>> from:
>>> >
>>> > FAILED: libwidevinecdmadapter.so
>>> > ../../../../../../../../work/llvm/build.goma/bin/clang++ -shared
>>> libwidevinecdm.so -Wl,--fatal-warnings -Wl,--build-id=sha1 -fPIC
>>> -Wl,-z,noexecstack -Wl,-z,now -Wl,-z,relro -Wl,-z,defs -Wl,--no-as-needed
>>> -lpthread -Wl,--as-needed -fuse-ld=lld -Wl,--icf=all -flto=thin
>>> -Wl,--thinlto-jobs=8 -Wl,--thinlto-cache-dir=thinlto-cache
>>> -Wl,--thinlto-cache-policy,cache_size=10\% -Wl,--lto-O0
>>> -fwhole-program-vtables -m64 -Werror -Wl,-O1 -Wl,--gc-sections
>>> -Wl,--gdb-index -nostdlib++ --sysroot=../../build/linux/debian_stretch_amd64-sysroot
>>> -L../../build/linux/debian_stretch_amd64-sysroot/lib/x86_64-linux-gnu
>>> -Wl,-rpath-link=../../build/linux/debian_stretch_amd64-sysroot/lib/x86_64-linux-gnu
>>> -L../../build/linux/debian_stretch_amd64-sysroot/usr/lib/x86_64-linux-gnu
>>> -Wl,-rpath-link=../../build/linux/debian_stretch_amd64-sysroot/usr/lib/x86_64-linux-gnu
>>> -fsanitize=cfi-vcall -Wl,-rpath=\$ORIGIN/. -Wl,-rpath-link=. -o
>>> "./libwidevinecdmadapter.so" -Wl,-soname="libwidevinecdmadapter.so"
>>> @"./libwidevinecdmadapter.so.rsp"
>>> > /usr/local/google/work/chromium/src/out/release/../../../../
>>> ../../../../work/llvm/build.goma/bin/ld.lld: error: Found local symbol
>>> '_ZN8tcmalloc11ThreadCache17threadlocal_heap_E' in global part of
>>> symbol table in file libwidevinecdm.so
>>> > clang-6.0: error: linker command failed with exit code 1 (use -v to
>>> see invocation)
>>> > ninja: build stopped: subcommand failed.
>>> >
>>> > Maybe the erorr could be downgraded to a warning? (We'd need to not
>>> treat warnings as errors for this target on our side I suppose)
>>> >
>>> >
>>> > https://reviews.llvm.org/D41215
>>> _______________________________________________
>>> llvm-commits mailing list
>>> llvm-commits at lists.llvm.org
>>> http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-commits
>>>
>>
>>
>>
>> --
>> --
>> Peter
>>
>
>


-- 
-- 
Peter
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