Re: [musl] `musl-gcc -static` and lld/mold

[Rui Ueyama <rui314@gmail.com>]

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The below patch should fix the issue.

diff --git a/tools/musl-gcc.specs.sh b/tools/musl-gcc.specs.sh
index 30492574..ffb46d70 100644
--- a/tools/musl-gcc.specs.sh
+++ b/tools/musl-gcc.specs.sh
@@ -23,7 +23,7 @@ libgcc.a%s %:if-exists(libgcc_eh.a%s)
 crtendS.o%s $libdir/crtn.o

 *link:
--dynamic-linker $ldso -nostdlib %{shared:-shared} %{static:-static}
%{rdynamic:-export-dynamic}
+%{!static:-dynamic-linker $ldso} -nostdlib %{shared:-shared}
%{static:-static} %{rdynamic:-export-dynamic}

 *esp_link:

On Sun, Nov 13, 2022 at 8:46 AM Rui Ueyama <rui314@gmail.com> wrote:

> Let me try to create a patch.
>
> On Sun, Nov 13, 2022 at 8:38 AM Rich Felker <dalias@libc.org> wrote:
>
>> On Sun, Nov 13, 2022 at 08:11:29AM +0800, Rui Ueyama wrote:
>> > Hi,
>> >
>> > I think I found a musl-gcc issue. It looks like musl-gcc always appends
>> > `-dynamic-linker /lib/ld-musl-x86_64.so.1` even if `-static` is given.
>> That
>> > causes a created program to immediately crash on startup as you can see
>> > below:
>> >
>> > $ cat hello.c
>> > #include <stdio.h>
>> > int main() { printf("Hello\n"); }
>> >
>> > $ musl-gcc -static -fuse-ld=lld hello.c -o hello
>> >
>> > $ ./hello
>> > Segmentation fault (core dumped)
>> >
>> > $ musl-gcc -static -fuse-ld=lld hello.c -o hello -Wl,-no-dynamic-linker
>> > $ ./hello
>> > Hello
>> >
>> > This also happens to my new linker, mold, as well. `-dynamic-linker`
>> option
>> > is passed to the linker, and lld and mold do what it is told to do, so I
>> > don't think it is a linker's bug. Rather, it's a compiler front end's
>> bug
>> > that passes the unnecessary command line option. Can you not to append
>> > `-dynamic-linker` if `-static`?
>>
>> Yes, I think this should be fixed. It only works with bfd ld without
>> static pie (which we're also missing support for) because it just
>> ignores -dynamic-linker in the ET_EXEC case.
>>
>> Would you be willing to propose a candidate patch? I believe this has
>> been raised before in the context of static pie not working with
>> musl-gcc (it didn't exist when the wrapper was added) so ideally that
>> will get fixed too.
>>
>> Rich
>>
>

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