[Bug ld/29592] New: [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

            Bug ID: 29592
           Summary: [2.39 Regression][bisected] Exec stack warning causes
                    go programs with cgo to fail to link on mips
           Product: binutils
           Version: 2.39
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: ld
          Assignee: unassigned at sourceware dot org
          Reporter: matoro_bugzilla_glibc at matoro dot tk
  Target Milestone: ---

65daf5bed68f3e792e80f7c9a12871fd71da32a2 is the first bad commit
commit 65daf5bed68f3e792e80f7c9a12871fd71da32a2
Author: Nick Clifton <nickc@redhat.com>
Date:   Wed Apr 20 13:37:51 2022 +0100

    Add linker warning for when it creates an executable stack.

       PR 29072

On mips, since this commit, all linking prints the following warning:

/usr/lib/gcc/mips64-unknown-linux-gnu/12.2.0/../../../../mips64-unknown-linux-gnu/bin/ld:
warning:
/usr/lib/gcc/mips64-unknown-linux-gnu/12.2.0/../../../../lib64/Scrt1.o:
requires executable stack (because the .note.GNU-stack section is executable)

This seems to be harmless most of the time.  However this commit also seems to
have made it impossible to link golang programs (including golang itself) when
cgo is enabled (which is the default unless explicitly disabled with
CGO_ENABLED=0).  The linker will print the following error thousands of times,
one for every single local symbol:

+ ./cmd/dist/dist bootstrap -a
Building Go toolchain1 using /usr/lib/go-bootstrap.
Building Go bootstrap cmd/go (go_bootstrap) using Go toolchain1.
Building Go toolchain2 using go_bootstrap and Go toolchain1.
Building Go toolchain3 using go_bootstrap and Go toolchain2.
Building packages and commands for linux/mips64.
# cmd/trace
/var/tmp/portage/dev-lang/go-1.19.1/work/go/pkg/tool/linux_mips64/link: running
mips64-unknown-linux-gnu-gcc failed: exit status 1
/var/tmp/portage/dev-lang/go-1.19.1/temp/go-link-3757955373/go.o: in function
`internal/cpu.Initialize':
/usr/lib/go/src/internal/cpu/cpu.go:123:(.text+0x14): relocation R_MIPS_26
against `a local symbol' cannot be used when making a shared object; recompile
with -fPIC
/usr/lib/go/src/internal/cpu/cpu.go:124:(.text+0x30): relocation R_MIPS_HI16
against `a local symbol' cannot be used when making a shared object; recompile
with -fPIC
/var/tmp/portage/dev-lang/go-1.19.1/temp/go-link-3757955373/go.o: in function
`internal/cpu.Initialize':
/usr/lib/go/src/internal/cpu/cpu_mips64x.go:22:(.text+0x40): relocation
R_MIPS_26 against `a local symbol' cannot be used when making a shared object;
recompile with -fPIC
/var/tmp/portage/dev-lang/go-1.19.1/temp/go-link-3757955373/go.o: in function
`internal/cpu.doinit':
/usr/lib/go/src/internal/cpu/cpu_mips64x.go:23:(.text+0x54): relocation
R_MIPS_HI16 against `a local symbol' cannot be used when making a shared
object; recompile with -fPIC
/usr/lib/go/src/internal/cpu/cpu_mips64x.go:23:(.text+0x64): relocation
R_MIPS_HI16 against `a local symbol' cannot be used when making a shared
object; recompile with -fPIC
/usr/lib/go/src/internal/cpu/cpu_mips64x.go:22:(.text+0x78): relocation
R_MIPS_HI16 against `a local symbol' cannot be used when making a shared
object; recompile with -fPIC
/usr/lib/go/src/internal/cpu/cpu_mips64x.go:22:(.text+0x84): relocation
R_MIPS_HI16 against `a local symbol' cannot be used when making a shared
object; recompile with -fPIC
/usr/lib/go/src/internal/cpu/cpu_mips64x.go:22:(.text+0x90): relocation
R_MIPS_HI16 against `a local symbol' cannot be used when making a shared
object; recompile with -fPIC
/usr/lib/go/src/internal/cpu/cpu_mips64x.go:22:(.text+0xa4): relocation
R_MIPS_HI16 against `a local symbol' cannot be used when making a shared
object; recompile with -fPIC
/usr/lib/go/src/internal/cpu/cpu_mips64x.go:22:(.text+0xb8): relocation
R_MIPS_HI16 against `a local symbol' cannot be used when making a shared
object; recompile with -fPIC
/usr/lib/go/src/internal/cpu/cpu_mips64x.go:22:(.text+0xc4): relocation
R_MIPS_26 against `a local symbol' cannot be used when making a shared object;
recompile with -fPIC
/usr/lib/go/src/internal/cpu/cpu_mips64x.go:27:(.text+0xcc): relocation
R_MIPS_HI16 against `a local symbol' cannot be used when making a shared
object; recompile with -fPIC
/usr/lib/go/src/internal/cpu/cpu_mips64x.go:27:(.text+0xe4): relocation
R_MIPS_HI16 against `a local symbol' cannot be used when making a shared
object; recompile with -fPIC
/var/tmp/portage/dev-lang/go-1.19.1/temp/go-link-3757955373/go.o: in function
`internal/cpu.Initialize':
/usr/lib/go/src/internal/cpu/cpu.go:125:(.text+0x100): relocation R_MIPS_26
against `a local symbol' cannot be used when making a shared object; recompile
with -fPIC
/var/tmp/portage/dev-lang/go-1.19.1/temp/go-link-3757955373/go.o: in function
`internal/cpu.processOptions':
/usr/lib/go/src/internal/cpu/cpu.go:148:(.text+0x130): relocation R_MIPS_26
against `a local symbol' cannot be used when making a shared object; recompile
with -fPIC
/usr/lib/go/src/internal/cpu/cpu.go:180:(.text+0x34c): relocation R_MIPS_HI16
against `a local symbol' cannot be used when making a shared object; recompile
with -fPIC
/usr/lib/go/src/internal/cpu/cpu.go:187:(.text+0x368): relocation R_MIPS_HI16
against `a local symbol' cannot be used when making a shared object; recompile
with -fPIC
/usr/lib/go/src/internal/cpu/cpu.go:175:(.text+0x384): relocation R_MIPS_26
against `a local symbol' cannot be used when making a shared object; recompile
with -fPIC
/usr/lib/go/src/internal/cpu/cpu.go:175:(.text+0x38c): relocation R_MIPS_HI16
against `a local symbol' cannot be used when making a shared object; recompile
with -fPIC
/usr/lib/go/src/internal/cpu/cpu.go:175:(.text+0x3a4): relocation R_MIPS_26
against `a local symbol' cannot be used when making a shared object; recompile
with -fPIC
/usr/lib/go/src/internal/cpu/cpu.go:175:(.text+0x3bc): relocation R_MIPS_26
against `a local symbol' cannot be used when making a shared object; recompile
with -fPIC
/usr/lib/go/src/internal/cpu/cpu.go:175:(.text+0x3c4): relocation R_MIPS_HI16
against `a local symbol' cannot be used when making a shared object; recompile
with -fPIC
/usr/lib/go/src/internal/cpu/cpu.go:175:(.text+0x3dc): relocation R_MIPS_26
against `a local symbol' cannot be used when making a shared object; recompile
with -fPIC
/usr/lib/go/src/internal/cpu/cpu.go:175:(.text+0x3f4): relocation R_MIPS_26
against `a local symbol' cannot be used when making a shared object; recompile
with -fPIC
/usr/lib/go/src/internal/cpu/cpu.go:175:(.text+0x3fc): relocation R_MIPS_HI16
against `a local symbol' cannot be used when making a shared object; recompile
with -fPIC
/usr/lib/go/src/internal/cpu/cpu.go:175:(.text+0x414): relocation R_MIPS_26
against `a local symbol' cannot be used when making a shared object; recompile
with -fPIC
/usr/lib/go/src/internal/cpu/cpu.go:175:(.text+0x41c): relocation R_MIPS_26
against `a local symbol' cannot be used when making a shared object; recompile
with -fPIC
/usr/lib/go/src/internal/cpu/cpu.go:163:(.text+0x43c): relocation R_MIPS_26
against `a local symbol' cannot be used when making a shared object; recompile
with -fPIC
/usr/lib/go/src/internal/cpu/cpu.go:163:(.text+0x444): relocation R_MIPS_HI16
against `a local symbol' cannot be used when making a shared object; recompile
with -fPIC
/usr/lib/go/src/internal/cpu/cpu.go:163:(.text+0x45c): relocation R_MIPS_26
against `a local symbol' cannot be used when making a shared object; recompile
with -fPIC
/usr/lib/go/src/internal/cpu/cpu.go:163:(.text+0x474): relocation R_MIPS_26
against `a local symbol' cannot be used when making a shared object; recompile
with -fPIC


And so on for a huge length, eventually erroring.  There is one final warning
at the end:

/usr/lib/gcc/mips64-unknown-linux-gnu/12.2.0/../../../../mips64-unknown-linux-gnu/bin/ld:
warning: creating DT_TEXTREL in a PIE

Linking C programs, other than the execstack warning, still works even after
this commit; only golang programs are affected.

-- 
You are receiving this mail because:
You are on the CC list for the bug.