[PATCH] riscv: vector: Fix data pointer constraints in context save/restore
Troy Mitchell
troy.mitchell at linux.dev
Tue Sep 8 06:03:37 PDT 2026
The standard vector save/restore asm advances datap but declares it as
input-only. An inlined caller reusing the original pointer may therefore
use the advanced address instead.
Declare datap as read-write so the compiler can preserve the original
pointer when needed.
Fixes: 03c3fcd9941a ("riscv: Introduce struct/helpers to save/restore per-task Vector state")
Signed-off-by: Troy Mitchell <troy.mitchell at linux.dev>
---
arch/riscv/include/asm/vector.h | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/arch/riscv/include/asm/vector.h b/arch/riscv/include/asm/vector.h
index fffe72a772080..c7fd6d50a7a47 100644
--- a/arch/riscv/include/asm/vector.h
+++ b/arch/riscv/include/asm/vector.h
@@ -230,7 +230,7 @@ static inline void __riscv_v_vstate_save(struct __riscv_v_ext_state *save_to,
"add %1, %1, %0\n\t"
"vse8.v v24, (%1)\n\t"
".option pop\n\t"
- : "=&r" (vl) : "r" (datap) : "memory");
+ : "=&r" (vl), "+r" (datap) : : "memory");
}
riscv_v_disable();
}
@@ -266,7 +266,7 @@ static inline void __riscv_v_vstate_restore(struct __riscv_v_ext_state *restore_
"add %1, %1, %0\n\t"
"vle8.v v24, (%1)\n\t"
".option pop\n\t"
- : "=&r" (vl) : "r" (datap) : "memory");
+ : "=&r" (vl), "+r" (datap) : : "memory");
}
__vstate_csr_restore(restore_from);
riscv_v_disable();
---
base-commit: cee9395acd8043be0644b25c34bfa86623f2b935
change-id: 20260908-riscv-vector-asm-fix-27ed36623934
Best regards,
--
Troy Mitchell <troy.mitchell at linux.dev>
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