[PATCH 1/2] riscv, bpf: use lw when reading int cpu in BPF_MOV64_PERCPU_REG

Radim Krčmář rkrcmar at ventanamicro.com
Tue Aug 12 02:02:55 PDT 2025


emit_ld 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: 19c56d4e5be1 ("riscv, bpf: add internal-only MOV instruction to resolve per-CPU addrs")
Cc: <stable at vger.kernel.org>
Signed-off-by: Radim Krčmář <rkrcmar at ventanamicro.com>
---
 arch/riscv/net/bpf_jit_comp64.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/riscv/net/bpf_jit_comp64.c b/arch/riscv/net/bpf_jit_comp64.c
index 10e01ff06312..6e1554d89681 100644
--- a/arch/riscv/net/bpf_jit_comp64.c
+++ b/arch/riscv/net/bpf_jit_comp64.c
@@ -1356,7 +1356,7 @@ int bpf_jit_emit_insn(const struct bpf_insn *insn, struct rv_jit_context *ctx,
 				emit_mv(rd, rs, ctx);
 #ifdef CONFIG_SMP
 			/* Load current CPU number in T1 */
-			emit_ld(RV_REG_T1, offsetof(struct thread_info, cpu),
+			emit_lw(RV_REG_T1, offsetof(struct thread_info, cpu),
 				RV_REG_TP, ctx);
 			/* Load address of __per_cpu_offset array in T2 */
 			emit_addr(RV_REG_T2, (u64)&__per_cpu_offset, extra_pass, ctx);
-- 
2.50.0




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