From a45b402bb2ec47fcb140d86098f035382680a31d Mon Sep 17 00:00:00 2001 From: Xi Wang Date: Fri, 8 May 2015 06:39:51 +0100 Subject: arm64: bpf: fix signedness bug in loading 64-bit immediate [ Upstream commit 1e4df6b7208140f3c49f316d33a409d3a161f350 ] Consider "(u64)insn1.imm << 32 | imm" in the arm64 JIT. Since imm is signed 32-bit, it is sign-extended to 64-bit, losing the high 32 bits. The fix is to convert imm to u32 first, which will be zero-extended to u64 implicitly. Cc: Zi Shen Lim Cc: Alexei Starovoitov Cc: Catalin Marinas Cc: Fixes: 30d3d94cc3d5 ("arm64: bpf: add 'load 64-bit immediate' instruction") Signed-off-by: Xi Wang [will: removed non-arm64 bits and redundant casting] Signed-off-by: Will Deacon Signed-off-by: Sasha Levin --- arch/arm64/net/bpf_jit_comp.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/arm64/net/bpf_jit_comp.c b/arch/arm64/net/bpf_jit_comp.c index edba042b2325..dc6a4842683a 100644 --- a/arch/arm64/net/bpf_jit_comp.c +++ b/arch/arm64/net/bpf_jit_comp.c @@ -487,7 +487,7 @@ emit_cond_jmp: return -EINVAL; } - imm64 = (u64)insn1.imm << 32 | imm; + imm64 = (u64)insn1.imm << 32 | (u32)imm; emit_a64_mov_i64(dst, imm64, ctx); return 1; -- cgit v1.2.3