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bpf, x86_64: remove obsolete exception handling from div/mod 

Since we've changed div/mod exception handling for src_reg in
eBPF verifier itself, remove the leftovers from x86_64 JIT.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
hifive-unleashed-5.1
Daniel Borkmann 2018-01-26 23:33:40 +01:00 committed by Alexei Starovoitov
parent f6b1b3bf0d
commit 3e5b1a39d7
1 changed files with 0 additions and 20 deletions
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20
arch/x86/net/bpf_jit_comp.c
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@ -568,26 +568,6 @@ static int do_jit(struct bpf_prog *bpf_prog, int *addrs, u8 *image,
*/
EMIT2(0x31, 0xd2);
if (BPF_SRC(insn->code) == BPF_X) {
/* if (src_reg == 0) return 0 */
/* cmp r11, 0 */
EMIT4(0x49, 0x83, 0xFB, 0x00);
/* jne .+9 (skip over pop, pop, xor and jmp) */
EMIT2(X86_JNE, 1 + 1 + 2 + 5);
EMIT1(0x5A); /* pop rdx */
EMIT1(0x58); /* pop rax */
EMIT2(0x31, 0xc0); /* xor eax, eax */
/* jmp cleanup_addr
* addrs[i] - 11, because there are 11 bytes
* after this insn: div, mov, pop, pop, mov
*/
jmp_offset = ctx->cleanup_addr - (addrs[i] - 11);
EMIT1_off32(0xE9, jmp_offset);
}
if (BPF_CLASS(insn->code) == BPF_ALU64)
/* div r11 */
EMIT3(0x49, 0xF7, 0xF3);