On Mon, 2024-12-09 at 09:31 +0100, Ard Biesheuvel wrote: > Given that this is relatively new toolchain behavior, I'd suggest > fixing the compiler to emit weak external references via GOT entries > even when -mdirect-extern-access is in effect. I'm working on an approach in the linker instead. A PC-relative address in +/- 2GiB range is pcalau12i.d $a0, %pc_hi20(sym + addend) addi.d $a0, $a0, %pc_lo12(sym + addend) If doing a static linking, when sym is weak undefined, we should just load addend. The compiler already guarantees addend is in [-2**31, 2**31) range, so we just need to rewrite the pair to lu12i.w $a0, ((addend + 0x800) & ~0x7ff) addi.d $a0, $a0, (addend & 0x7ff) OTOH if not doing a static linking, the user shouldn't use -mdirect- extern-access at all [this rule is the thing related to copy relocation: if copy relocation was available it would be possibly valid to use - mdirect-extern-access w/o static linking] and the linker is correct to report an error (but the error message is unclear and I need to fix it anyway). -- Xi Ruoyao <xry111@xxxxxxxxxxx> School of Aerospace Science and Technology, Xidian University
