diff options
| author | Yonghong Song <yonghong.song@linux.dev> | 2023-07-28 04:12:02 +0300 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2023-07-28 04:52:33 +0300 |
| commit | 8100928c881482a73ed8bd499d602bab0fe55608 (patch) | |
| tree | b172651bb95631daa750fc3313f1633dd23423a4 /kernel/bpf/core.c | |
| parent | 1f9a1ea821ff25353a0e80d971e7958cd55b47a3 (diff) | |
| download | linux-8100928c881482a73ed8bd499d602bab0fe55608.tar.xz | |
bpf: Support new sign-extension mov insns
Add interpreter/jit support for new sign-extension mov insns.
The original 'MOV' insn is extended to support reg-to-reg
signed version for both ALU and ALU64 operations. For ALU mode,
the insn->off value of 8 or 16 indicates sign-extension
from 8- or 16-bit value to 32-bit value. For ALU64 mode,
the insn->off value of 8/16/32 indicates sign-extension
from 8-, 16- or 32-bit value to 64-bit value.
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20230728011202.3712300-1-yonghong.song@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'kernel/bpf/core.c')
| -rw-r--r-- | kernel/bpf/core.c | 28 |
1 files changed, 26 insertions, 2 deletions
diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c index 01b72fc001f6..c37c454b09eb 100644 --- a/kernel/bpf/core.c +++ b/kernel/bpf/core.c @@ -61,6 +61,7 @@ #define AX regs[BPF_REG_AX] #define ARG1 regs[BPF_REG_ARG1] #define CTX regs[BPF_REG_CTX] +#define OFF insn->off #define IMM insn->imm struct bpf_mem_alloc bpf_global_ma; @@ -1739,13 +1740,36 @@ select_insn: DST = -DST; CONT; ALU_MOV_X: - DST = (u32) SRC; + switch (OFF) { + case 0: + DST = (u32) SRC; + break; + case 8: + DST = (u32)(s8) SRC; + break; + case 16: + DST = (u32)(s16) SRC; + break; + } CONT; ALU_MOV_K: DST = (u32) IMM; CONT; ALU64_MOV_X: - DST = SRC; + switch (OFF) { + case 0: + DST = SRC; + break; + case 8: + DST = (s8) SRC; + break; + case 16: + DST = (s16) SRC; + break; + case 32: + DST = (s32) SRC; + break; + } CONT; ALU64_MOV_K: DST = IMM; |