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authorTiezhu Yang <yangtiezhu@loongson.cn>2023-12-09 15:49:16 +0800
committerHuacai Chen <chenhuacai@loongson.cn>2023-12-09 15:49:16 +0800
commite2f7b3d8b4b300956a77fa1ab084c931ba1c7421 (patch)
treec678faf50b2669118ad237bd7c63959c57f8c760 /arch/loongarch/net
parent772cbe948fb07389639d4e698a2d3299f8e538b8 (diff)
LoongArch: BPF: Fix unconditional bswap instructions
We can see that "bswap32: Takes an unsigned 32-bit number in either big- or little-endian format and returns the equivalent number with the same bit width but opposite endianness" in BPF Instruction Set Specification, so it should clear the upper 32 bits in "case 32:" for both BPF_ALU and BPF_ALU64. [root@linux fedora]# echo 1 > /proc/sys/net/core/bpf_jit_enable [root@linux fedora]# modprobe test_bpf Before: test_bpf: #313 BSWAP 32: 0x0123456789abcdef -> 0xefcdab89 jited:1 ret 1460850314 != -271733879 (0x5712ce8a != 0xefcdab89)FAIL (1 times) test_bpf: #317 BSWAP 32: 0xfedcba9876543210 -> 0x10325476 jited:1 ret -1460850316 != 271733878 (0xa8ed3174 != 0x10325476)FAIL (1 times) After: test_bpf: #313 BSWAP 32: 0x0123456789abcdef -> 0xefcdab89 jited:1 4 PASS test_bpf: #317 BSWAP 32: 0xfedcba9876543210 -> 0x10325476 jited:1 4 PASS Fixes: 4ebf9216e7df ("LoongArch: BPF: Support unconditional bswap instructions") Acked-by: Hengqi Chen <hengqi.chen@gmail.com> Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Diffstat (limited to 'arch/loongarch/net')
-rw-r--r--arch/loongarch/net/bpf_jit.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/arch/loongarch/net/bpf_jit.c b/arch/loongarch/net/bpf_jit.c
index cd002f183648..4fcd6cd6da23 100644
--- a/arch/loongarch/net/bpf_jit.c
+++ b/arch/loongarch/net/bpf_jit.c
@@ -774,8 +774,8 @@ static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx, bool ext
break;
case 32:
emit_insn(ctx, revb2w, dst, dst);
- /* zero-extend 32 bits into 64 bits */
- emit_zext_32(ctx, dst, is32);
+ /* clear the upper 32 bits */
+ emit_zext_32(ctx, dst, true);
break;
case 64:
emit_insn(ctx, revbd, dst, dst);