RISC-V: errata: Use medany for relocatable builds

[ Upstream commit bb58e1579f431d42469b6aed0f03eff383ba6db5 ]

We're trying to mix non-PIC/PIE objects into the otherwise-PIE
relocatable kernels, to avoid GOT/PLT references during early boot
alternative resolution (which happens before the GOT/PLT are set up).

riscv64-unknown-linux-gnu-ld: arch/riscv/errata/sifive/errata.o: relocation R_RISCV_HI20 against `tlb_flush_all_threshold' can not be used when making a shared object; recompile with -fPIC
riscv64-unknown-linux-gnu-ld: arch/riscv/errata/thead/errata.o: relocation R_RISCV_HI20 against `riscv_cbom_block_size' can not be used when making a shared object; recompile with -fPIC

Fixes: 8dc2a7e8027f ("riscv: Fix relocatable kernels with early alternatives using -fno-pie")
Link: https://lore.kernel.org/r/20250326224506.27165-2-palmer@rivosinc.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/arch/riscv/errata/Makefile b/arch/riscv/errata/Makefile
index 8a27394851233dbda1a4f0841e1e7e918b61f8e0..f96ace8ea1df14af272cbeaaa6355f37ffd4cc86 100644 (file)
--- a/arch/riscv/errata/Makefile
+++ b/arch/riscv/errata/Makefile
@@ -1,5 +1,9 @@
 ifdef CONFIG_RELOCATABLE
-KBUILD_CFLAGS += -fno-pie
+# We can't use PIC/PIE when handling early-boot errata parsing, as the kernel
+# doesn't have a GOT setup at that point.  So instead just use medany: it's
+# usually position-independent, so it should be good enough for the errata
+# handling.
+KBUILD_CFLAGS += -fno-pie -mcmodel=medany
 endif
 
 obj-$(CONFIG_ERRATA_ANDES) += andes/