linux-stable/arch/arm64/net
Hou Tao e4a41c2c1f bpf, arm64: Use emit_addr_mov_i64() for BPF_PSEUDO_FUNC
The following error is reported when running "./test_progs -t for_each"
under arm64:

  bpf_jit: multi-func JIT bug 58 != 56
  [...]
  JIT doesn't support bpf-to-bpf calls

The root cause is the size of BPF_PSEUDO_FUNC instruction increases
from 2 to 3 after the address of called bpf-function is settled and
there are two bpf-to-bpf calls in test_pkt_access. The generated
instructions are shown below:

  0x48:  21 00 C0 D2    movz x1, #0x1, lsl #32
  0x4c:  21 00 80 F2    movk x1, #0x1

  0x48:  E1 3F C0 92    movn x1, #0x1ff, lsl #32
  0x4c:  41 FE A2 F2    movk x1, #0x17f2, lsl #16
  0x50:  81 70 9F F2    movk x1, #0xfb84

Fixing it by using emit_addr_mov_i64() for BPF_PSEUDO_FUNC, so
the size of jited image will not change.

Fixes: 69c087ba62 ("bpf: Add bpf_for_each_map_elem() helper")
Signed-off-by: Hou Tao <houtao1@huawei.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20211231151018.3781550-1-houtao1@huawei.com
2022-01-05 20:43:08 +01:00
..
bpf_jit.h Merge branch 'for-next/bti' into for-next/core 2020-05-28 18:00:51 +01:00
bpf_jit_comp.c bpf, arm64: Use emit_addr_mov_i64() for BPF_PSEUDO_FUNC 2022-01-05 20:43:08 +01:00
Makefile treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00