diff options
Diffstat (limited to 'kernel/bpf/core.c')
| -rw-r--r-- | kernel/bpf/core.c | 43 |
1 files changed, 35 insertions, 8 deletions
diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c index 3ece2da55625..7b675a451ec8 100644 --- a/kernel/bpf/core.c +++ b/kernel/bpf/core.c @@ -1422,6 +1422,27 @@ static int bpf_jit_blind_insn(const struct bpf_insn *from, *to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd); *to++ = BPF_STX_MEM(from->code, from->dst_reg, BPF_REG_AX, from->off); break; + + case BPF_ST | BPF_PROBE_MEM32 | BPF_DW: + case BPF_ST | BPF_PROBE_MEM32 | BPF_W: + case BPF_ST | BPF_PROBE_MEM32 | BPF_H: + case BPF_ST | BPF_PROBE_MEM32 | BPF_B: + *to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ + from->imm); + *to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd); + /* + * Cannot use BPF_STX_MEM() macro here as it + * hardcodes BPF_MEM mode, losing PROBE_MEM32 + * and breaking arena addressing in the JIT. + */ + *to++ = (struct bpf_insn) { + .code = BPF_STX | BPF_PROBE_MEM32 | + BPF_SIZE(from->code), + .dst_reg = from->dst_reg, + .src_reg = BPF_REG_AX, + .off = from->off, + }; + break; } out: return to - to_buff; @@ -1736,6 +1757,12 @@ bool bpf_opcode_in_insntable(u8 code) } #ifndef CONFIG_BPF_JIT_ALWAYS_ON +/* Absolute value of s32 without undefined behavior for S32_MIN */ +static u32 abs_s32(s32 x) +{ + return x >= 0 ? (u32)x : -(u32)x; +} + /** * ___bpf_prog_run - run eBPF program on a given context * @regs: is the array of MAX_BPF_EXT_REG eBPF pseudo-registers @@ -1900,8 +1927,8 @@ select_insn: DST = do_div(AX, (u32) SRC); break; case 1: - AX = abs((s32)DST); - AX = do_div(AX, abs((s32)SRC)); + AX = abs_s32((s32)DST); + AX = do_div(AX, abs_s32((s32)SRC)); if ((s32)DST < 0) DST = (u32)-AX; else @@ -1928,8 +1955,8 @@ select_insn: DST = do_div(AX, (u32) IMM); break; case 1: - AX = abs((s32)DST); - AX = do_div(AX, abs((s32)IMM)); + AX = abs_s32((s32)DST); + AX = do_div(AX, abs_s32((s32)IMM)); if ((s32)DST < 0) DST = (u32)-AX; else @@ -1955,8 +1982,8 @@ select_insn: DST = (u32) AX; break; case 1: - AX = abs((s32)DST); - do_div(AX, abs((s32)SRC)); + AX = abs_s32((s32)DST); + do_div(AX, abs_s32((s32)SRC)); if (((s32)DST < 0) == ((s32)SRC < 0)) DST = (u32)AX; else @@ -1982,8 +2009,8 @@ select_insn: DST = (u32) AX; break; case 1: - AX = abs((s32)DST); - do_div(AX, abs((s32)IMM)); + AX = abs_s32((s32)DST); + do_div(AX, abs_s32((s32)IMM)); if (((s32)DST < 0) == ((s32)IMM < 0)) DST = (u32)AX; else |