lld fails to link kernel modules on FreeBSD/arm: can't create dynamic relocation R_ARM_ABS32 against local symbol in readonly segment

[emaste]

Bugzilla Link	33423
Resolution	INVALID
Resolved on	Jun 21, 2017 11:01
Version	unspecified
OS	FreeBSD
Blocks	#23588

Extended Description

Bug created for tracking - reproduction tarball will be added.

While linking the FreeBSD/arm kernel modules the linking fails with errors of the form:

ld -m armelf_fbsd -Bshareable -d -warn-common -o accf_data.ko.full accf_data.kld
ld: error: can't create dynamic relocation R_ARM_ABS32 against local symbol in readonly segment

defined in accf_data.kld
referenced by accf_data.kld:(__set_modmetadata_set_sym__mod_metadata_md_accf_data_on_kernel)

ld: error: can't create dynamic relocation R_ARM_ABS32 against local symbol in readonly segment

defined in accf_data.kld
referenced by accf_data.kld:(__set_modmetadata_set_sym__mod_metadata_md_accf_data)

ld: error: can't create dynamic relocation R_ARM_ABS32 against local symbol in readonly segment

defined in accf_data.kld
referenced by accf_data.kld:(__set_sysinit_set_sym_accf_datamodule_sys_init)*** [accf_data.ko.full] Error code 1

[llvmbot]

ping on the reproduction tarball :-)

[llvmbot]

I noticed something similar in another build. Taking a look.

[emaste]

reproducer .tar

[llvmbot]

I noticed something similar in another build. Taking a look.

At least in the case I hit it was just "-z text" being the default. Can you try passing "-z notext"?

[emaste]

At least in the case I hit it was just "-z text" being the default. Can you
try passing "-z notext"?

Indeed, I am able to link the arm kernel modules with -z notext, and for kernel modules applying .text relocations is not unreasonable.

[llvmbot]

At least in the case I hit it was just "-z text" being the default. Can you
try passing "-z notext"?

Indeed, I am able to link the arm kernel modules with -z notext, and for
kernel modules applying .text relocations is not unreasonable.

Yes, a -z text .so is probably the most convenient format for a loadable module that is never shared.

[emaste]

For reference, addressed in FreeBSD here: https://svnweb.freebsd.org/changeset/base/320179

[emaste]

I've now run basic sanity tests with an LLD-linked FreeBSD kernel and modules on BeagleBone black and everything seems fine.

root@beaglebone:~ # readelf --string-dump=.comment sysctl -n kern.bootfile | grep -i link
[ 8a] Linker: LLD 5.0.0 (FreeBSD 305145)