On 5/21/26 5:57 PM, Egg12138 wrote:
> Commit 1ba9f8979426 ("vmlinux.lds: Unify TEXT_MAIN, DATA_MAIN,
> and related macros") made scripts/module.lds.S merge module input
> .text.* sections into the output .text section.
>
> On ARM, the paired unwind input sections keep their original names. A
> module can therefore contain .ARM.exidx.text.unlikely with sh_link
> pointing at .text, while .text.unlikely no longer exists.
>
> This is a valid ELF relationship, but ARM module_finalize() does not use
> sh_link when registering module unwind tables. It derives the target
> text section from the exidx section name instead:
>
> .ARM.exidx.text.unlikely -> .text.unlikely
>
> The lookup fails and the unwind table is not registered for the actual
> .text range. This can make module stack unwinding fail with:
>
> unwind: Index not found
>
> Keep the ARM module unwind output names in sync with the text sections
> that scripts/module.lds.S now produces. Coalesce the .ARM.exidx/.ARM.extab
> sections associated with .text.*, into the
> stable output names expected by the existing ARM module unwind code.
>
> Fixes: 1ba9f8979426 ("vmlinux.lds: Unify TEXT_MAIN, DATA_MAIN, and related
> macros")
> Signed-off-by: Egg12138 <[email protected]>
A Signed-off-by tag should use a known identity, see
Documentation/process/submitting-patches.rst, Developer's Certificate of
Origin 1.1 [1].
> ---
> arch/arm/include/asm/module.lds.h | 8 ++++++++
> 1 file changed, 8 insertions(+)
>
> diff --git a/arch/arm/include/asm/module.lds.h
> b/arch/arm/include/asm/module.lds.h
> index 0e7cb4e314b4..dc9adf8fa50e 100644
> --- a/arch/arm/include/asm/module.lds.h
> +++ b/arch/arm/include/asm/module.lds.h
> @@ -1,4 +1,12 @@
> /* SPDX-License-Identifier: GPL-2.0 */
> +
> +#ifndef CONFIG_ARCH_WANTS_MODULES_TEXT_SECTIONS
The Arm architecture support doesn't select
CONFIG_ARCH_WANTS_MODULES_TEXT_SECTIONS, so this #ifndef is not really
necessary. I suggest leaving these linker definitions unconditional, or
alternatively use '#ifdef CONFIG_ARM_UNWIND'.
> +SECTIONS {
> + .ARM.extab 0 : { *(.ARM.extab .ARM.extab.text
> .ARM.extab.text.[0-9a-zA-Z_]*) }
> + .ARM.exidx 0 : { *(.ARM.exidx .ARM.exidx.text
> .ARM.exidx.text.[0-9a-zA-Z_]*) }
> +}
> +#endif
> +
> #ifdef CONFIG_ARM_MODULE_PLTS
> SECTIONS {
> .plt : { BYTE(0) }
Besides the above nits, the patch looks ok to me. Please don't forget to
put it in Russell's patch tracker [2].
[1]
https://github.com/torvalds/linux/blob/v7.1-rc5/Documentation/process/submitting-patches.rst#developers-certificate-of-origin-11
[2] https://www.arm.linux.org.uk/developer/patches/
--
Thanks,
Petr
