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bpf: handle CONFIG_SMP=n configuration in x86 BPF JIT

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On non-SMP systems, there is no "per-CPU" data, it's just global data.
So in such case just don't do this_cpu_off-based per-CPU address adjustment.

Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202404040951.d4CUx5S6-lkp@intel.com/
Fixes: 7bdbf7446305 ("bpf: add special internal-only MOV instruction to resolve per-CPU addrs")
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20240404034726.2766740-1-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This commit is contained in:
Andrii Nakryiko 2024-04-03 20:47:26 -07:00 committed by Alexei Starovoitov
parent 519e1de94b
commit 1e9e0b8525
1 changed files with 3 additions and 4 deletions
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7
arch/x86/net/bpf_jit_comp.c
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@ -1383,15 +1383,14 @@ static int do_jit(struct bpf_prog *bpf_prog, int *addrs, u8 *image, u8 *rw_image
EMIT3(0x0F, 0x44, add_2reg(0xC0, AUX_REG, dst_reg));
break;
} else if (insn_is_mov_percpu_addr(insn)) {
u32 off = (u32)(unsigned long)&this_cpu_off;
/* mov <dst>, <src> (if necessary) */
EMIT_mov(dst_reg, src_reg);
#ifdef CONFIG_SMP
/* add <dst>, gs:[<off>] */
EMIT2(0x65, add_1mod(0x48, dst_reg));
EMIT3(0x03, add_1reg(0x04, dst_reg), 0x25);
EMIT(off, 4);
EMIT((u32)(unsigned long)&this_cpu_off, 4);
#endif
break;
}
fallthrough;