[Bug ld/29592] [2.39 Regression][bisected] Exec stack warning causes go programs with cgo to fail to link on mips

[matoro_bugzilla_glibc at matoro dot tk]

https://sourceware.org/bugzilla/show_bug.cgi?id=29592

--- Comment #6 from matoro <matoro_bugzilla_glibc at matoro dot tk> ---
*It's the other way around - CGO_ENABLED=1 is the default, creates a dynamic
binary, and that is the scenario where it is not working.  It works with
CGO_ENABLED=0, which creates a static binary, but that is a non-default
workaround.

I captured this by stopping the golang link command, and taking a snapshot of
its temporary link directory while frozen.  What confused me was that the
object code was *exactly the same* in both the good and bad directories!  Then
I compared the scripts with the linker invocations that I got out of pgrep and
saw that they were different.  The linker is getting invoked differently
depending on whether the execstack warning is enabled or not.

Without --enable-warn-execstack:
/usr/lib/gcc/mips64-unknown-linux-gnu/12.2.0/../../../../mips64-unknown-linux-gnu/bin/ld
-plugin /usr/libexec/gcc/mips64-unknown-linux-gnu/12.2.0/liblto_plugin.so
-plugin-opt=/usr/libexec/gcc/mips64-unknown-linux-gnu/12.2.0/lto-wrapper
-plugin-opt=-fresolution=/tmp/ccYpZeDT.res -plugin-opt=-pass-through=-lgcc
-plugin-opt=-pass-through=-lgcc_s -plugin-opt=-pass-through=-lc
-plugin-opt=-pass-through=-lgcc -plugin-opt=-pass-through=-lgcc_s
--eh-frame-hdr -EB -export-dynamic -dynamic-linker /lib64/ld.so.1 -melf64btsmip
-o go-sqlite3.test -s
/usr/lib/gcc/mips64-unknown-linux-gnu/12.2.0/../../../../lib64/crt1.o
/usr/lib/gcc/mips64-unknown-linux-gnu/12.2.0/../../../../lib64/crti.o
/usr/lib/gcc/mips64-unknown-linux-gnu/12.2.0/crtbegin.o
-L/usr/lib/gcc/mips64-unknown-linux-gnu/12.2.0
-L/usr/lib/gcc/mips64-unknown-linux-gnu/12.2.0/../../../../lib64
-L/lib64/../lib64 -L/usr/lib64/../lib64
-L/usr/lib/gcc/mips64-unknown-linux-gnu/12.2.0/../../../../mips64-unknown-linux-gnu/lib
-L/usr/lib/gcc/mips64-unknown-linux-gnu/12.2.0/../../.. -L/lib64 -L/usr/lib64
--compress-debug-sections=zlib /tmp/go-link-good/go.o
/tmp/go-link-good/000000.o /tmp/go-link-good/000001.o
/tmp/go-link-good/000002.o /tmp/go-link-good/000003.o
/tmp/go-link-good/000004.o /tmp/go-link-good/000005.o
/tmp/go-link-good/000006.o /tmp/go-link-good/000007.o
/tmp/go-link-good/000008.o /tmp/go-link-good/000009.o
/tmp/go-link-good/000010.o /tmp/go-link-good/000011.o
/tmp/go-link-good/000012.o /tmp/go-link-good/000013.o
/tmp/go-link-good/000014.o /tmp/go-link-good/000015.o
/tmp/go-link-good/000016.o /tmp/go-link-good/000017.o
/tmp/go-link-good/000018.o /tmp/go-link-good/000019.o
/tmp/go-link-good/000020.o /tmp/go-link-good/000021.o
/tmp/go-link-good/000022.o -ldl -lpthread -lgcc --push-state --as-needed
-lgcc_s --pop-state -lc -lgcc --push-state --as-needed -lgcc_s --pop-state
/usr/lib/gcc/mips64-unknown-linux-gnu/12.2.0/crtend.o
/usr/lib/gcc/mips64-unknown-linux-gnu/12.2.0/../../../../lib64/crtn.o

With --enable-warn-execstack:
/usr/lib/gcc/mips64-unknown-linux-gnu/12.2.0/../../../../mips64-unknown-linux-gnu/bin/ld
-plugin /usr/libexec/gcc/mips64-unknown-linux-gnu/12.2.0/liblto_plugin.so
-plugin-opt=/usr/libexec/gcc/mips64-unknown-linux-gnu/12.2.0/lto-wrapper
-plugin-opt=-fresolution=/tmp/ccexkDVx.res -plugin-opt=-pass-through=-lgcc
-plugin-opt=-pass-through=-lgcc_s -plugin-opt=-pass-through=-lc
-plugin-opt=-pass-through=-lgcc -plugin-opt=-pass-through=-lgcc_s
--eh-frame-hdr -EB -export-dynamic -dynamic-linker /lib64/ld.so.1 -melf64btsmip
-pie -o go-sqlite3.test -s
/usr/lib/gcc/mips64-unknown-linux-gnu/12.2.0/../../../../lib64/Scrt1.o
/usr/lib/gcc/mips64-unknown-linux-gnu/12.2.0/../../../../lib64/crti.o
/usr/lib/gcc/mips64-unknown-linux-gnu/12.2.0/crtbeginS.o
-L/usr/lib/gcc/mips64-unknown-linux-gnu/12.2.0
-L/usr/lib/gcc/mips64-unknown-linux-gnu/12.2.0/../../../../lib64
-L/lib64/../lib64 -L/usr/lib64/../lib64
-L/usr/lib/gcc/mips64-unknown-linux-gnu/12.2.0/../../../../mips64-unknown-linux-gnu/lib
-L/usr/lib/gcc/mips64-unknown-linux-gnu/12.2.0/../../.. -L/lib64 -L/usr/lib64
/tmp/go-link-bad/go.o /tmp/go-link-bad/000000.o /tmp/go-link-bad/000001.o
/tmp/go-link-bad/000002.o /tmp/go-link-bad/000003.o /tmp/go-link-bad/000004.o
/tmp/go-link-bad/000005.o /tmp/go-link-bad/000006.o /tmp/go-link-bad/000007.o
/tmp/go-link-bad/000008.o /tmp/go-link-bad/000009.o /tmp/go-link-bad/000010.o
/tmp/go-link-bad/000011.o /tmp/go-link-bad/000012.o /tmp/go-link-bad/000013.o
/tmp/go-link-bad/000014.o /tmp/go-link-bad/000015.o /tmp/go-link-bad/000016.o
/tmp/go-link-bad/000017.o /tmp/go-link-bad/000018.o /tmp/go-link-bad/000019.o
/tmp/go-link-bad/000020.o /tmp/go-link-bad/000021.o /tmp/go-link-bad/000022.o
-ldl -lpthread -lgcc --push-state --as-needed -lgcc_s --pop-state -lc -lgcc
--push-state --as-needed -lgcc_s --pop-state
/usr/lib/gcc/mips64-unknown-linux-gnu/12.2.0/crtendS.o
/usr/lib/gcc/mips64-unknown-linux-gnu/12.2.0/../../../../lib64/crtn.o


Diff:

7c7
< -plugin-opt=-fresolution=/tmp/ccYpZeDT.res
---
> -plugin-opt=-fresolution=/tmp/ccexkDVx.res
18a19
> -pie
22c23
< /usr/lib/gcc/mips64-unknown-linux-gnu/12.2.0/../../../../lib64/crt1.o
---
> /usr/lib/gcc/mips64-unknown-linux-gnu/12.2.0/../../../../lib64/Scrt1.o
24c25
< /usr/lib/gcc/mips64-unknown-linux-gnu/12.2.0/crtbegin.o
---
> /usr/lib/gcc/mips64-unknown-linux-gnu/12.2.0/crtbeginS.o
33,57c34,57
< --compress-debug-sections=zlib
< /tmp/go-link-good/go.o
< /tmp/go-link-good/000000.o
< /tmp/go-link-good/000001.o
< /tmp/go-link-good/000002.o
< /tmp/go-link-good/000003.o
< /tmp/go-link-good/000004.o
< /tmp/go-link-good/000005.o
< /tmp/go-link-good/000006.o
< /tmp/go-link-good/000007.o
< /tmp/go-link-good/000008.o
< /tmp/go-link-good/000009.o
< /tmp/go-link-good/000010.o
< /tmp/go-link-good/000011.o
< /tmp/go-link-good/000012.o
< /tmp/go-link-good/000013.o
< /tmp/go-link-good/000014.o
< /tmp/go-link-good/000015.o
< /tmp/go-link-good/000016.o
< /tmp/go-link-good/000017.o
< /tmp/go-link-good/000018.o
< /tmp/go-link-good/000019.o
< /tmp/go-link-good/000020.o
< /tmp/go-link-good/000021.o
< /tmp/go-link-good/000022.o
---
> /tmp/go-link-bad/go.o
> /tmp/go-link-bad/000000.o
> /tmp/go-link-bad/000001.o
> /tmp/go-link-bad/000002.o
> /tmp/go-link-bad/000003.o
> /tmp/go-link-bad/000004.o
> /tmp/go-link-bad/000005.o
> /tmp/go-link-bad/000006.o
> /tmp/go-link-bad/000007.o
> /tmp/go-link-bad/000008.o
> /tmp/go-link-bad/000009.o
> /tmp/go-link-bad/000010.o
> /tmp/go-link-bad/000011.o
> /tmp/go-link-bad/000012.o
> /tmp/go-link-bad/000013.o
> /tmp/go-link-bad/000014.o
> /tmp/go-link-bad/000015.o
> /tmp/go-link-bad/000016.o
> /tmp/go-link-bad/000017.o
> /tmp/go-link-bad/000018.o
> /tmp/go-link-bad/000019.o
> /tmp/go-link-bad/000020.o
> /tmp/go-link-bad/000021.o
> /tmp/go-link-bad/000022.o
71c71
< /usr/lib/gcc/mips64-unknown-linux-gnu/12.2.0/crtend.o
---
> /usr/lib/gcc/mips64-unknown-linux-gnu/12.2.0/crtendS.o


You can see that after the change, it seems to be enabling PIE in the bad
scenario, when it presumably should not.

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