linux-kernel - [PATCH 2/3] riscv: use lw instead of REG

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20250722160556.2216925-4-rkrcmar@ventanamicro.com>
Date: Tue, 22 Jul 2025 18:05:56 +0200
From: Radim Krčmář <rkrcmar@...tanamicro.com>
To: linux-riscv@...ts.infradead.org
Cc: linux-kernel@...r.kernel.org,
	Paul Walmsley <paul.walmsley@...ive.com>,
	Palmer Dabbelt <palmer@...belt.com>,
	Albert Ou <aou@...s.berkeley.edu>,
	Alexandre Ghiti <alex@...ti.fr>,
	Deepak Gupta <debug@...osinc.com>
Subject: [PATCH 2/3] riscv: use lw instead of REG_L when reading int cpu

REG_L is wrong, because thread_info.cpu is 32-bit, not xlen-bit wide.
The struct currently has a hole after cpu, so little endian accesses
seemed fine.

Fixes: be97d0db5f44 ("riscv: VMAP_STACK overflow detection thread-safe")
Fixes: 503638e0babf ("riscv: Stop emitting preventive sfence.vma for new vmalloc mappings")
Signed-off-by: Radim Krčmář <rkrcmar@...tanamicro.com>
---
 arch/riscv/include/asm/asm.h | 2 +-
 arch/riscv/kernel/entry.S    | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/riscv/include/asm/asm.h b/arch/riscv/include/asm/asm.h
index b3022bc224ec..93b1e4ce34d1 100644
--- a/arch/riscv/include/asm/asm.h
+++ b/arch/riscv/include/asm/asm.h
@@ -91,7 +91,7 @@
 #endif
 
 .macro asm_per_cpu dst sym tmp
-	REG_L \tmp, TASK_TI_CPU(tp)
+	lw    \tmp, TASK_TI_CPU(tp)
 	slli  \tmp, \tmp, PER_CPU_OFFSET_SHIFT
 	la    \dst, __per_cpu_offset
 	add   \dst, \dst, \tmp
diff --git a/arch/riscv/kernel/entry.S b/arch/riscv/kernel/entry.S
index 75656afa2d6b..4fdf187a62bf 100644
--- a/arch/riscv/kernel/entry.S
+++ b/arch/riscv/kernel/entry.S
@@ -46,7 +46,7 @@
 	 * a0 = &new_vmalloc[BIT_WORD(cpu)]
 	 * a1 = BIT_MASK(cpu)
 	 */
-	REG_L 	a2, TASK_TI_CPU(tp)
+	lw	a2, TASK_TI_CPU(tp)
 	/*
 	 * Compute the new_vmalloc element position:
 	 * (cpu / 64) * 8 = (cpu >> 6) << 3
-- 
2.50.0