queue-7.2/riscv-vector-fix-data-pointer-constraints-in-context.patch

From ffb03799308c5af624b4b5d1b683c59fb328511c Mon Sep 17 00:00:00 2001
From: Sasha Levin <sashal@kernel.org>
Date: Mon, 5 Oct 2026 19:02:37 -0600
Subject: riscv: vector: Fix data pointer constraints in context save/restore

From: Troy Mitchell <troy.mitchell@linux.dev>

[ Upstream commit 572b25f3a6453d8e7fc28cc0cefe41ed15be166c ]

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@linux.dev>
Reviewed-by: GUO Ren (XuanTie) <guoren@kernel.org>
Reviewed-by: Aurelien Jarno <aurelien@aurel32.net>
Reviewed-by: Andy Chiu <tchiu@tenstorrent.com>
Link: https://patch.msgid.link/20260908-riscv-vector-asm-fix-v1-1-147f314efb2b@linux.dev
Signed-off-by: Paul Walmsley <pjw@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 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 00cb9c0982b1a..e94f81cedda56 100644
--- a/arch/riscv/include/asm/vector.h
+++ b/arch/riscv/include/asm/vector.h
@@ -225,7 +225,7 @@ 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();
 }
@@ -261,7 +261,7 @@ 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();
-- 
2.53.0