[PATCH v2] RISC-V: fix compile error from deduplicated __ALTERNATIVE_CFG_2

Heiko Stuebner heiko at sntech.de
Thu Jan 5 11:26:10 PST 2023


From: Heiko Stuebner <heiko.stuebner at vrull.eu>

On the non-assembler-side wrapping alternative-macros inside other macros
to prevent duplication of code works, as the end result will just be a
string that gets fed to the asm instruction.

In real assembler code, wrapping .macro blocks inside other .macro blocks
brings more restrictions on usage it seems and the optimization done by
commit 2ba8c7dc71c0 ("riscv: Don't duplicate __ALTERNATIVE_CFG in __ALTERNATIVE_CFG_2")
results in a compile error like:

../arch/riscv/lib/strcmp.S: Assembler messages:
../arch/riscv/lib/strcmp.S:15: Error: too many positional arguments
../arch/riscv/lib/strcmp.S:15: Error: backward ref to unknown label "886:"
../arch/riscv/lib/strcmp.S:15: Error: backward ref to unknown label "887:"
../arch/riscv/lib/strcmp.S:15: Error: backward ref to unknown label "886:"
../arch/riscv/lib/strcmp.S:15: Error: backward ref to unknown label "887:"
../arch/riscv/lib/strcmp.S:15: Error: backward ref to unknown label "886:"
../arch/riscv/lib/strcmp.S:15: Error: attempt to move .org backwards

Wrapping the variables containing assembler code in quotes solves this issue,
compilation and the code in question still works and objdump also shows sane
decompiled results of the affected code.

Fixes: 2ba8c7dc71c0 ("riscv: Don't duplicate __ALTERNATIVE_CFG in __ALTERNATIVE_CFG_2")
Signed-off-by: Heiko Stuebner <heiko.stuebner at vrull.eu>
---
changes in v2:
- don't revert the affected cleanup but use quotes around the parts

Tested on qemu + Allwinner D1 + specially created test-cases using
ALTERNATIVE_2 in full assembler .S files

 arch/riscv/include/asm/alternative-macros.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/riscv/include/asm/alternative-macros.h b/arch/riscv/include/asm/alternative-macros.h
index 7226e2462584..2c0f4c887289 100644
--- a/arch/riscv/include/asm/alternative-macros.h
+++ b/arch/riscv/include/asm/alternative-macros.h
@@ -46,7 +46,7 @@
 
 .macro ALTERNATIVE_CFG_2 old_c, new_c_1, vendor_id_1, errata_id_1, enable_1,	\
 				new_c_2, vendor_id_2, errata_id_2, enable_2
-	ALTERNATIVE_CFG \old_c, \new_c_1, \vendor_id_1, \errata_id_1, \enable_1
+	ALTERNATIVE_CFG "\old_c", "\new_c_1", \vendor_id_1, \errata_id_1, \enable_1
 	ALT_NEW_CONTENT \vendor_id_2, \errata_id_2, \enable_2, \new_c_2
 .endm
 
-- 
2.35.1




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