Re: [PATCH v4 0/2] riscv: Add remaining module relocations and tests

[Conor Dooley]

Hey Charlie,

On Tue, Oct 17, 2023 at 10:34:15PM -0700, Charlie Jenkins wrote:
> A handful of module relocations were missing, this patch includes the
> remaining ones. I also wrote some test cases to ensure that module
> loading works properly. Some relocations cannot be supported in the
> kernel, these include the ones that rely on thread local storage and
> dynamic linking.
> 
> ULEB128 handling is a bit special because SET and SUB relocations must
> happen together, and SET must happen before SUB. A psABI proposal [1]
> mandates that the first SET_ULEB128 that appears before a SUB_ULEB128
> is the associated SET_ULEB128.
> 
> This can be tested by enabling KUNIT, RUNTIME_KERNEL_TESTING_MENU, and
> RISCV_MODULE_LINKING_KUNIT.
> 
> [1] https://github.com/riscv-non-isa/riscv-elf-psabi-doc/pull/403
> 
> Signed-off-by: Charlie Jenkins <charlie@xxxxxxxxxxxx>
> ---
> Changes in v4:
> - Complete removal of R_RISCV_RVC_LUI
> - Fix bug in R_RISCV_SUB6 linking
> - Only build ULEB128 tests if supported by toolchain
> - Link to v3: https://lore.kernel.org/r/20231016-module_relocations-v3-0-a667fd6071e9@xxxxxxxxxxxx

On patch 2/2:

../arch/riscv/kernel/tests/module_test/test_uleb128.S:18:17: error: unknown relocation name
../arch/riscv/kernel/tests/module_test/test_uleb128.S:19:17: error: unknown relocation name

Same toolchain configuration in the patchwork automation as before.

Cheers,
Conor.

> 
> Changes in v3:
> - Add prototypes to test_module_linking_main as recommended by intel
>   zero day bot
> - Improve efficiency of ULEB128 pair matching
> - Link to v2: https://lore.kernel.org/r/20231006-module_relocations-v2-0-47566453fedc@xxxxxxxxxxxx
> 
> Changes in v2:
> - Added ULEB128 relocations
> - Link to v1: https://lore.kernel.org/r/20230913-module_relocations-v1-0-bb3d8467e793@xxxxxxxxxxxx
> 
> ---
> Charlie Jenkins (2):
>       riscv: Add remaining module relocations
>       riscv: Add tests for riscv module loading
> 
>  arch/riscv/Kconfig.debug                           |   1 +
>  arch/riscv/include/uapi/asm/elf.h                  |   5 +-
>  arch/riscv/kernel/Makefile                         |   1 +
>  arch/riscv/kernel/module.c                         | 207 ++++++++++++++++++---
>  arch/riscv/kernel/tests/Kconfig.debug              |  35 ++++
>  arch/riscv/kernel/tests/Makefile                   |   1 +
>  arch/riscv/kernel/tests/module_test/Makefile       |  15 ++
>  .../tests/module_test/test_module_linking_main.c   |  85 +++++++++
>  arch/riscv/kernel/tests/module_test/test_set16.S   |  23 +++
>  arch/riscv/kernel/tests/module_test/test_set32.S   |  20 ++
>  arch/riscv/kernel/tests/module_test/test_set6.S    |  23 +++
>  arch/riscv/kernel/tests/module_test/test_set8.S    |  23 +++
>  arch/riscv/kernel/tests/module_test/test_sub16.S   |  22 +++
>  arch/riscv/kernel/tests/module_test/test_sub32.S   |  22 +++
>  arch/riscv/kernel/tests/module_test/test_sub6.S    |  22 +++
>  arch/riscv/kernel/tests/module_test/test_sub64.S   |  27 +++
>  arch/riscv/kernel/tests/module_test/test_sub8.S    |  22 +++
>  arch/riscv/kernel/tests/module_test/test_uleb128.S |  20 ++
>  18 files changed, 548 insertions(+), 26 deletions(-)
> ---
> base-commit: 4d320c2d9a2b22f53523a1b012cda17a50220965
> change-id: 20230908-module_relocations-f63ced651bd7
> -- 
> - Charlie
>

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