diff options
author | David S. Miller <davem@davemloft.net> | 2019-01-28 19:38:33 -0800 |
---|---|---|
committer | David S. Miller <davem@davemloft.net> | 2019-01-28 19:38:33 -0800 |
commit | ec7146db150082737cbfeacaae0f33e42c95cf18 (patch) | |
tree | 9fd307588cd07ed2f42d9df4554bc83ab19cf382 /kernel/bpf | |
parent | 343917b410ba7250dbbe59a8330feffaf36eaab8 (diff) | |
parent | 3d2af27a84a8474e510f5d8362303bfbee946308 (diff) |
Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Daniel Borkmann says:
====================
pull-request: bpf-next 2019-01-29
The following pull-request contains BPF updates for your *net-next* tree.
The main changes are:
1) Teach verifier dead code removal, this also allows for optimizing /
removing conditional branches around dead code and to shrink the
resulting image. Code store constrained architectures like nfp would
have hard time doing this at JIT level, from Jakub.
2) Add JMP32 instructions to BPF ISA in order to allow for optimizing
code generation for 32-bit sub-registers. Evaluation shows that this
can result in code reduction of ~5-20% compared to 64 bit-only code
generation. Also add implementation for most JITs, from Jiong.
3) Add support for __int128 types in BTF which is also needed for
vmlinux's BTF conversion to work, from Yonghong.
4) Add a new command to bpftool in order to dump a list of BPF-related
parameters from the system or for a specific network device e.g. in
terms of available prog/map types or helper functions, from Quentin.
5) Add AF_XDP sock_diag interface for querying sockets from user
space which provides information about the RX/TX/fill/completion
rings, umem, memory usage etc, from Björn.
6) Add skb context access for skb_shared_info->gso_segs field, from Eric.
7) Add support for testing flow dissector BPF programs by extending
existing BPF_PROG_TEST_RUN infrastructure, from Stanislav.
8) Split BPF kselftest's test_verifier into various subgroups of tests
in order better deal with merge conflicts in this area, from Jakub.
9) Add support for queue/stack manipulations in bpftool, from Stanislav.
10) Document BTF, from Yonghong.
11) Dump supported ELF section names in libbpf on program load
failure, from Taeung.
12) Silence a false positive compiler warning in verifier's BTF
handling, from Peter.
13) Fix help string in bpftool's feature probing, from Prashant.
14) Remove duplicate includes in BPF kselftests, from Yue.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'kernel/bpf')
-rw-r--r-- | kernel/bpf/btf.c | 104 | ||||
-rw-r--r-- | kernel/bpf/core.c | 273 | ||||
-rw-r--r-- | kernel/bpf/disasm.c | 34 | ||||
-rw-r--r-- | kernel/bpf/offload.c | 35 | ||||
-rw-r--r-- | kernel/bpf/verifier.c | 624 |
5 files changed, 774 insertions, 296 deletions
diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c index befe570be5ba..3d661f0606fe 100644 --- a/kernel/bpf/btf.c +++ b/kernel/bpf/btf.c @@ -157,7 +157,7 @@ * */ -#define BITS_PER_U64 (sizeof(u64) * BITS_PER_BYTE) +#define BITS_PER_U128 (sizeof(u64) * BITS_PER_BYTE * 2) #define BITS_PER_BYTE_MASK (BITS_PER_BYTE - 1) #define BITS_PER_BYTE_MASKED(bits) ((bits) & BITS_PER_BYTE_MASK) #define BITS_ROUNDDOWN_BYTES(bits) ((bits) >> 3) @@ -525,7 +525,7 @@ const struct btf_type *btf_type_by_id(const struct btf *btf, u32 type_id) /* * Regular int is not a bit field and it must be either - * u8/u16/u32/u64. + * u8/u16/u32/u64 or __int128. */ static bool btf_type_int_is_regular(const struct btf_type *t) { @@ -538,7 +538,8 @@ static bool btf_type_int_is_regular(const struct btf_type *t) if (BITS_PER_BYTE_MASKED(nr_bits) || BTF_INT_OFFSET(int_data) || (nr_bytes != sizeof(u8) && nr_bytes != sizeof(u16) && - nr_bytes != sizeof(u32) && nr_bytes != sizeof(u64))) { + nr_bytes != sizeof(u32) && nr_bytes != sizeof(u64) && + nr_bytes != (2 * sizeof(u64)))) { return false; } @@ -1063,9 +1064,9 @@ static int btf_int_check_member(struct btf_verifier_env *env, nr_copy_bits = BTF_INT_BITS(int_data) + BITS_PER_BYTE_MASKED(struct_bits_off); - if (nr_copy_bits > BITS_PER_U64) { + if (nr_copy_bits > BITS_PER_U128) { btf_verifier_log_member(env, struct_type, member, - "nr_copy_bits exceeds 64"); + "nr_copy_bits exceeds 128"); return -EINVAL; } @@ -1119,9 +1120,9 @@ static int btf_int_check_kflag_member(struct btf_verifier_env *env, bytes_offset = BITS_ROUNDDOWN_BYTES(struct_bits_off); nr_copy_bits = nr_bits + BITS_PER_BYTE_MASKED(struct_bits_off); - if (nr_copy_bits > BITS_PER_U64) { + if (nr_copy_bits > BITS_PER_U128) { btf_verifier_log_member(env, struct_type, member, - "nr_copy_bits exceeds 64"); + "nr_copy_bits exceeds 128"); return -EINVAL; } @@ -1168,9 +1169,9 @@ static s32 btf_int_check_meta(struct btf_verifier_env *env, nr_bits = BTF_INT_BITS(int_data) + BTF_INT_OFFSET(int_data); - if (nr_bits > BITS_PER_U64) { + if (nr_bits > BITS_PER_U128) { btf_verifier_log_type(env, t, "nr_bits exceeds %zu", - BITS_PER_U64); + BITS_PER_U128); return -EINVAL; } @@ -1211,31 +1212,93 @@ static void btf_int_log(struct btf_verifier_env *env, btf_int_encoding_str(BTF_INT_ENCODING(int_data))); } +static void btf_int128_print(struct seq_file *m, void *data) +{ + /* data points to a __int128 number. + * Suppose + * int128_num = *(__int128 *)data; + * The below formulas shows what upper_num and lower_num represents: + * upper_num = int128_num >> 64; + * lower_num = int128_num & 0xffffffffFFFFFFFFULL; + */ + u64 upper_num, lower_num; + +#ifdef __BIG_ENDIAN_BITFIELD + upper_num = *(u64 *)data; + lower_num = *(u64 *)(data + 8); +#else + upper_num = *(u64 *)(data + 8); + lower_num = *(u64 *)data; +#endif + if (upper_num == 0) + seq_printf(m, "0x%llx", lower_num); + else + seq_printf(m, "0x%llx%016llx", upper_num, lower_num); +} + +static void btf_int128_shift(u64 *print_num, u16 left_shift_bits, + u16 right_shift_bits) +{ + u64 upper_num, lower_num; + +#ifdef __BIG_ENDIAN_BITFIELD + upper_num = print_num[0]; + lower_num = print_num[1]; +#else + upper_num = print_num[1]; + lower_num = print_num[0]; +#endif + + /* shake out un-needed bits by shift/or operations */ + if (left_shift_bits >= 64) { + upper_num = lower_num << (left_shift_bits - 64); + lower_num = 0; + } else { + upper_num = (upper_num << left_shift_bits) | + (lower_num >> (64 - left_shift_bits)); + lower_num = lower_num << left_shift_bits; + } + + if (right_shift_bits >= 64) { + lower_num = upper_num >> (right_shift_bits - 64); + upper_num = 0; + } else { + lower_num = (lower_num >> right_shift_bits) | + (upper_num << (64 - right_shift_bits)); + upper_num = upper_num >> right_shift_bits; + } + +#ifdef __BIG_ENDIAN_BITFIELD + print_num[0] = upper_num; + print_num[1] = lower_num; +#else + print_num[0] = lower_num; + print_num[1] = upper_num; +#endif +} + static void btf_bitfield_seq_show(void *data, u8 bits_offset, u8 nr_bits, struct seq_file *m) { u16 left_shift_bits, right_shift_bits; u8 nr_copy_bytes; u8 nr_copy_bits; - u64 print_num; + u64 print_num[2] = {}; nr_copy_bits = nr_bits + bits_offset; nr_copy_bytes = BITS_ROUNDUP_BYTES(nr_copy_bits); - print_num = 0; - memcpy(&print_num, data, nr_copy_bytes); + memcpy(print_num, data, nr_copy_bytes); #ifdef __BIG_ENDIAN_BITFIELD left_shift_bits = bits_offset; #else - left_shift_bits = BITS_PER_U64 - nr_copy_bits; + left_shift_bits = BITS_PER_U128 - nr_copy_bits; #endif - right_shift_bits = BITS_PER_U64 - nr_bits; - - print_num <<= left_shift_bits; - print_num >>= right_shift_bits; + right_shift_bits = BITS_PER_U128 - nr_bits; - seq_printf(m, "0x%llx", print_num); + btf_int128_shift(print_num, left_shift_bits, right_shift_bits); + btf_int128_print(m, print_num); } @@ -1250,7 +1313,7 @@ static void btf_int_bits_seq_show(const struct btf *btf, /* * bits_offset is at most 7. - * BTF_INT_OFFSET() cannot exceed 64 bits. + * BTF_INT_OFFSET() cannot exceed 128 bits. */ total_bits_offset = bits_offset + BTF_INT_OFFSET(int_data); data += BITS_ROUNDDOWN_BYTES(total_bits_offset); @@ -1274,6 +1337,9 @@ static void btf_int_seq_show(const struct btf *btf, const struct btf_type *t, } switch (nr_bits) { + case 128: + btf_int128_print(m, data); + break; case 64: if (sign) seq_printf(m, "%lld", *(s64 *)data); diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c index f908b9356025..a7bcb23bee84 100644 --- a/kernel/bpf/core.c +++ b/kernel/bpf/core.c @@ -307,15 +307,16 @@ int bpf_prog_calc_tag(struct bpf_prog *fp) return 0; } -static int bpf_adj_delta_to_imm(struct bpf_insn *insn, u32 pos, u32 delta, - u32 curr, const bool probe_pass) +static int bpf_adj_delta_to_imm(struct bpf_insn *insn, u32 pos, s32 end_old, + s32 end_new, u32 curr, const bool probe_pass) { const s64 imm_min = S32_MIN, imm_max = S32_MAX; + s32 delta = end_new - end_old; s64 imm = insn->imm; - if (curr < pos && curr + imm + 1 > pos) + if (curr < pos && curr + imm + 1 >= end_old) imm += delta; - else if (curr > pos + delta && curr + imm + 1 <= pos + delta) + else if (curr >= end_new && curr + imm + 1 < end_new) imm -= delta; if (imm < imm_min || imm > imm_max) return -ERANGE; @@ -324,15 +325,16 @@ static int bpf_adj_delta_to_imm(struct bpf_insn *insn, u32 pos, u32 delta, return 0; } -static int bpf_adj_delta_to_off(struct bpf_insn *insn, u32 pos, u32 delta, - u32 curr, const bool probe_pass) +static int bpf_adj_delta_to_off(struct bpf_insn *insn, u32 pos, s32 end_old, + s32 end_new, u32 curr, const bool probe_pass) { const s32 off_min = S16_MIN, off_max = S16_MAX; + s32 delta = end_new - end_old; s32 off = insn->off; - if (curr < pos && curr + off + 1 > pos) + if (curr < pos && curr + off + 1 >= end_old) off += delta; - else if (curr > pos + delta && curr + off + 1 <= pos + delta) + else if (curr >= end_new && curr + off + 1 < end_new) off -= delta; if (off < off_min || off > off_max) return -ERANGE; @@ -341,10 +343,10 @@ static int bpf_adj_delta_to_off(struct bpf_insn *insn, u32 pos, u32 delta, return 0; } -static int bpf_adj_branches(struct bpf_prog *prog, u32 pos, u32 delta, - const bool probe_pass) +static int bpf_adj_branches(struct bpf_prog *prog, u32 pos, s32 end_old, + s32 end_new, const bool probe_pass) { - u32 i, insn_cnt = prog->len + (probe_pass ? delta : 0); + u32 i, insn_cnt = prog->len + (probe_pass ? end_new - end_old : 0); struct bpf_insn *insn = prog->insnsi; int ret = 0; @@ -356,22 +358,23 @@ static int bpf_adj_branches(struct bpf_prog *prog, u32 pos, u32 delta, * do any other adjustments. Therefore skip the patchlet. */ if (probe_pass && i == pos) { - i += delta + 1; - insn++; + i = end_new; + insn = prog->insnsi + end_old; } code = insn->code; - if (BPF_CLASS(code) != BPF_JMP || + if ((BPF_CLASS(code) != BPF_JMP && + BPF_CLASS(code) != BPF_JMP32) || BPF_OP(code) == BPF_EXIT) continue; /* Adjust offset of jmps if we cross patch boundaries. */ if (BPF_OP(code) == BPF_CALL) { if (insn->src_reg != BPF_PSEUDO_CALL) continue; - ret = bpf_adj_delta_to_imm(insn, pos, delta, i, - probe_pass); + ret = bpf_adj_delta_to_imm(insn, pos, end_old, + end_new, i, probe_pass); } else { - ret = bpf_adj_delta_to_off(insn, pos, delta, i, - probe_pass); + ret = bpf_adj_delta_to_off(insn, pos, end_old, + end_new, i, probe_pass); } if (ret) break; @@ -421,7 +424,7 @@ struct bpf_prog *bpf_patch_insn_single(struct bpf_prog *prog, u32 off, * we afterwards may not fail anymore. */ if (insn_adj_cnt > cnt_max && - bpf_adj_branches(prog, off, insn_delta, true)) + bpf_adj_branches(prog, off, off + 1, off + len, true)) return NULL; /* Several new instructions need to be inserted. Make room @@ -453,13 +456,25 @@ struct bpf_prog *bpf_patch_insn_single(struct bpf_prog *prog, u32 off, * the ship has sailed to reverse to the original state. An * overflow cannot happen at this point. */ - BUG_ON(bpf_adj_branches(prog_adj, off, insn_delta, false)); + BUG_ON(bpf_adj_branches(prog_adj, off, off + 1, off + len, false)); bpf_adj_linfo(prog_adj, off, insn_delta); return prog_adj; } +int bpf_remove_insns(struct bpf_prog *prog, u32 off, u32 cnt) +{ + /* Branch offsets can't overflow when program is shrinking, no need + * to call bpf_adj_branches(..., true) here + */ + memmove(prog->insnsi + off, prog->insnsi + off + cnt, + sizeof(struct bpf_insn) * (prog->len - off - cnt)); + prog->len -= cnt; + + return WARN_ON_ONCE(bpf_adj_branches(prog, off, off + cnt, off, false)); +} + void bpf_prog_kallsyms_del_subprogs(struct bpf_prog *fp) { int i; @@ -934,6 +949,27 @@ static int bpf_jit_blind_insn(const struct bpf_insn *from, *to++ = BPF_JMP_REG(from->code, from->dst_reg, BPF_REG_AX, off); break; + case BPF_JMP32 | BPF_JEQ | BPF_K: + case BPF_JMP32 | BPF_JNE | BPF_K: + case BPF_JMP32 | BPF_JGT | BPF_K: + case BPF_JMP32 | BPF_JLT | BPF_K: + case BPF_JMP32 | BPF_JGE | BPF_K: + case BPF_JMP32 | BPF_JLE | BPF_K: + case BPF_JMP32 | BPF_JSGT | BPF_K: + case BPF_JMP32 | BPF_JSLT | BPF_K: + case BPF_JMP32 | BPF_JSGE | BPF_K: + case BPF_JMP32 | BPF_JSLE | BPF_K: + case BPF_JMP32 | BPF_JSET | BPF_K: + /* Accommodate for extra offset in case of a backjump. */ + off = from->off; + if (off < 0) + off -= 2; + *to++ = BPF_ALU32_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm); + *to++ = BPF_ALU32_IMM(BPF_XOR, BPF_REG_AX, imm_rnd); + *to++ = BPF_JMP32_REG(from->code, from->dst_reg, BPF_REG_AX, + off); + break; + case BPF_LD | BPF_IMM | BPF_DW: *to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ aux[1].imm); *to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd); @@ -1130,6 +1166,31 @@ EXPORT_SYMBOL_GPL(__bpf_call_base); INSN_2(JMP, CALL), \ /* Exit instruction. */ \ INSN_2(JMP, EXIT), \ + /* 32-bit Jump instructions. */ \ + /* Register based. */ \ + INSN_3(JMP32, JEQ, X), \ + INSN_3(JMP32, JNE, X), \ + INSN_3(JMP32, JGT, X), \ + INSN_3(JMP32, JLT, X), \ + INSN_3(JMP32, JGE, X), \ + INSN_3(JMP32, JLE, X), \ + INSN_3(JMP32, JSGT, X), \ + INSN_3(JMP32, JSLT, X), \ + INSN_3(JMP32, JSGE, X), \ + INSN_3(JMP32, JSLE, X), \ + INSN_3(JMP32, JSET, X), \ + /* Immediate based. */ \ + INSN_3(JMP32, JEQ, K), \ + INSN_3(JMP32, JNE, K), \ + INSN_3(JMP32, JGT, K), \ + INSN_3(JMP32, JLT, K), \ + INSN_3(JMP32, JGE, K), \ + INSN_3(JMP32, JLE, K), \ + INSN_3(JMP32, JSGT, K), \ + INSN_3(JMP32, JSLT, K), \ + INSN_3(JMP32, JSGE, K), \ + INSN_3(JMP32, JSLE, K), \ + INSN_3(JMP32, JSET, K), \ /* Jump instructions. */ \ /* Register based. */ \ INSN_3(JMP, JEQ, X), \ @@ -1390,145 +1451,49 @@ select_insn: out: CONT; } - /* JMP */ JMP_JA: insn += insn->off; CONT; - JMP_JEQ_X: - if (DST == SRC) { - insn += insn->off; - CONT_JMP; - } - CONT; - JMP_JEQ_K: - if (DST == IMM) { - insn += insn->off; - CONT_JMP; - } - CONT; - JMP_JNE_X: - if (DST != SRC) { - insn += insn->off; - CONT_JMP; - } - CONT; - JMP_JNE_K: - if (DST != IMM) { - insn += insn->off; - CONT_JMP; - } - CONT; - JMP_JGT_X: - if (DST > SRC) { - insn += insn->off; - CONT_JMP; - } - CONT; - JMP_JGT_K: - if (DST > IMM) { - insn += insn->off; - CONT_JMP; - } - CONT; - JMP_JLT_X: - if (DST < SRC) { - insn += insn->off; - CONT_JMP; - } - CONT; - JMP_JLT_K: - if (DST < IMM) { - insn += insn->off; - CONT_JMP; - } - CONT; - JMP_JGE_X: - if (DST >= SRC) { - insn += insn->off; - CONT_JMP; - } - CONT; - JMP_JGE_K: - if (DST >= IMM) { - insn += insn->off; - CONT_JMP; - } - CONT; - JMP_JLE_X: - if (DST <= SRC) { - insn += insn->off; - CONT_JMP; - } - CONT; - JMP_JLE_K: - if (DST <= IMM) { - insn += insn->off; - CONT_JMP; - } - CONT; - JMP_JSGT_X: - if (((s64) DST) > ((s64) SRC)) { - insn += insn->off; - CONT_JMP; - } - CONT; - JMP_JSGT_K: - if (((s64) DST) > ((s64) IMM)) { - insn += insn->off; - CONT_JMP; - } - CONT; - JMP_JSLT_X: - if (((s64) DST) < ((s64) SRC)) { - insn += insn->off; - CONT_JMP; - } - CONT; - JMP_JSLT_K: - if (((s64) DST) < ((s64) IMM)) { - insn += insn->off; - CONT_JMP; - } - CONT; - JMP_JSGE_X: - if (((s64) DST) >= ((s64) SRC)) { - insn += insn->off; - CONT_JMP; - } - CONT; - JMP_JSGE_K: - if (((s64) DST) >= ((s64) IMM)) { - insn += insn->off; - CONT_JMP; - } - CONT; - JMP_JSLE_X: - if (((s64) DST) <= ((s64) SRC)) { - insn += insn->off; - CONT_JMP; - } - CONT; - JMP_JSLE_K: - if (((s64) DST) <= ((s64) IMM)) { - insn += insn->off; - CONT_JMP; - } - CONT; - JMP_JSET_X: - if (DST & SRC) { - insn += insn->off; - CONT_JMP; - } - CONT; - JMP_JSET_K: - if (DST & IMM) { - insn += insn->off; - CONT_JMP; - } - CONT; JMP_EXIT: return BPF_R0; - + /* JMP */ +#define COND_JMP(SIGN, OPCODE, CMP_OP) \ + JMP_##OPCODE##_X: \ + if ((SIGN##64) DST CMP_OP (SIGN##64) SRC) { \ + insn += insn->off; \ + CONT_JMP; \ + } \ + CONT; \ + JMP32_##OPCODE##_X: \ + if ((SIGN##32) DST CMP_OP (SIGN##32) SRC) { \ + insn += insn->off; \ + CONT_JMP; \ + } \ + CONT; \ + JMP_##OPCODE##_K: \ + if ((SIGN##64) DST CMP_OP (SIGN##64) IMM) { \ + insn += insn->off; \ + CONT_JMP; \ + } \ + CONT; \ + JMP32_##OPCODE##_K: \ + if ((SIGN##32) DST CMP_OP (SIGN##32) IMM) { \ + insn += insn->off; \ + CONT_JMP; \ + } \ + CONT; + COND_JMP(u, JEQ, ==) + COND_JMP(u, JNE, !=) + COND_JMP(u, JGT, >) + COND_JMP(u, JLT, <) + COND_JMP(u, JGE, >=) + COND_JMP(u, JLE, <=) + COND_JMP(u, JSET, &) + COND_JMP(s, JSGT, >) + COND_JMP(s, JSLT, <) + COND_JMP(s, JSGE, >=) + COND_JMP(s, JSLE, <=) +#undef COND_JMP /* STX and ST and LDX*/ #define LDST(SIZEOP, SIZE) \ STX_MEM_##SIZEOP: \ diff --git a/kernel/bpf/disasm.c b/kernel/bpf/disasm.c index d6b76377cb6e..de73f55e42fd 100644 --- a/kernel/bpf/disasm.c +++ b/kernel/bpf/disasm.c @@ -67,7 +67,7 @@ const char *const bpf_class_string[8] = { [BPF_STX] = "stx", [BPF_ALU] = "alu", [BPF_JMP] = "jmp", - [BPF_RET] = "BUG", + [BPF_JMP32] = "jmp32", [BPF_ALU64] = "alu64", }; @@ -136,23 +136,22 @@ void print_bpf_insn(const struct bpf_insn_cbs *cbs, else print_bpf_end_insn(verbose, cbs->private_data, insn); } else if (BPF_OP(insn->code) == BPF_NEG) { - verbose(cbs->private_data, "(%02x) r%d = %s-r%d\n", - insn->code, insn->dst_reg, - class == BPF_ALU ? "(u32) " : "", + verbose(cbs->private_data, "(%02x) %c%d = -%c%d\n", + insn->code, class == BPF_ALU ? 'w' : 'r', + insn->dst_reg, class == BPF_ALU ? 'w' : 'r', insn->dst_reg); } else if (BPF_SRC(insn->code) == BPF_X) { - verbose(cbs->private_data, "(%02x) %sr%d %s %sr%d\n", - insn->code, class == BPF_ALU ? "(u32) " : "", + verbose(cbs->private_data, "(%02x) %c%d %s %c%d\n", + insn->code, class == BPF_ALU ? 'w' : 'r', insn->dst_reg, bpf_alu_string[BPF_OP(insn->code) >> 4], - class == BPF_ALU ? "(u32) " : "", + class == BPF_ALU ? 'w' : 'r', insn->src_reg); } else { - verbose(cbs->private_data, "(%02x) %sr%d %s %s%d\n", - insn->code, class == BPF_ALU ? "(u32) " : "", + verbose(cbs->private_data, "(%02x) %c%d %s %d\n", + insn->code, class == BPF_ALU ? 'w' : 'r', insn->dst_reg, bpf_alu_string[BPF_OP(insn->code) >> 4], - class == BPF_ALU ? "(u32) " : "", insn->imm); } } else if (class == BPF_STX) { @@ -220,7 +219,7 @@ void print_bpf_insn(const struct bpf_insn_cbs *cbs, verbose(cbs->private_data, "BUG_ld_%02x\n", insn->code); return; } - } else if (class == BPF_JMP) { + } else if (class == BPF_JMP32 || class == BPF_JMP) { u8 opcode = BPF_OP(insn->code); if (opcode == BPF_CALL) { @@ -244,13 +243,18 @@ void print_bpf_insn(const struct bpf_insn_cbs *cbs, } else if (insn->code == (BPF_JMP | BPF_EXIT)) { verbose(cbs->private_data, "(%02x) exit\n", insn->code); } else if (BPF_SRC(insn->code) == BPF_X) { - verbose(cbs->private_data, "(%02x) if r%d %s r%d goto pc%+d\n", - insn->code, insn->dst_reg, + verbose(cbs->private_data, + "(%02x) if %c%d %s %c%d goto pc%+d\n", + insn->code, class == BPF_JMP32 ? 'w' : 'r', + insn->dst_reg, bpf_jmp_string[BPF_OP(insn->code) >> 4], + class == BPF_JMP32 ? 'w' : 'r', insn->src_reg, insn->off); } else { - verbose(cbs->private_data, "(%02x) if r%d %s 0x%x goto pc%+d\n", - insn->code, insn->dst_reg, + verbose(cbs->private_data, + "(%02x) if %c%d %s 0x%x goto pc%+d\n", + insn->code, class == BPF_JMP32 ? 'w' : 'r', + insn->dst_reg, bpf_jmp_string[BPF_OP(insn->code) >> 4], insn->imm, insn->off); } diff --git a/kernel/bpf/offload.c b/kernel/bpf/offload.c index 54cf2b9c44a4..39dba8c90331 100644 --- a/kernel/bpf/offload.c +++ b/kernel/bpf/offload.c @@ -173,6 +173,41 @@ int bpf_prog_offload_finalize(struct bpf_verifier_env *env) return ret; } +void +bpf_prog_offload_replace_insn(struct bpf_verifier_env *env, u32 off, + struct bpf_insn *insn) +{ + const struct bpf_prog_offload_ops *ops; + struct bpf_prog_offload *offload; + int ret = -EOPNOTSUPP; + + down_read(&bpf_devs_lock); + offload = env->prog->aux->offload; + if (offload) { + ops = offload->offdev->ops; + if (!offload->opt_failed && ops->replace_insn) + ret = ops->replace_insn(env, off, insn); + offload->opt_failed |= ret; + } + up_read(&bpf_devs_lock); +} + +void +bpf_prog_offload_remove_insns(struct bpf_verifier_env *env, u32 off, u32 cnt) +{ + struct bpf_prog_offload *offload; + int ret = -EOPNOTSUPP; + + down_read(&bpf_devs_lock); + offload = env->prog->aux->offload; + if (offload) { + if (!offload->opt_failed && offload->offdev->ops->remove_insns) + ret = offload->offdev->ops->remove_insns(env, off, cnt); + offload->opt_failed |= ret; + } + up_read(&bpf_devs_lock); +} + static void __bpf_prog_offload_destroy(struct bpf_prog *prog) { struct bpf_prog_offload *offload = prog->aux->offload; diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 56674a7c3778..8c1c21cd50b4 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -1095,7 +1095,7 @@ static int check_subprogs(struct bpf_verifier_env *env) for (i = 0; i < insn_cnt; i++) { u8 code = insn[i].code; - if (BPF_CLASS(code) != BPF_JMP) + if (BPF_CLASS(code) != BPF_JMP && BPF_CLASS(code) != BPF_JMP32) goto next; if (BPF_OP(code) == BPF_EXIT || BPF_OP(code) == BPF_CALL) goto next; @@ -4031,11 +4031,50 @@ static void find_good_pkt_pointers(struct bpf_verifier_state *vstate, * 0 - branch will not be taken and fall-through to next insn * -1 - unknown. Example: "if (reg < 5)" is unknown when register value range [0,10] */ -static int is_branch_taken(struct bpf_reg_state *reg, u64 val, u8 opcode) +static int is_branch_taken(struct bpf_reg_state *reg, u64 val, u8 opcode, + bool is_jmp32) { + struct bpf_reg_state reg_lo; + s64 sval; + if (__is_pointer_value(false, reg)) return -1; + if (is_jmp32) { + reg_lo = *reg; + reg = ®_lo; + /* For JMP32, only low 32 bits are compared, coerce_reg_to_size + * could truncate high bits and update umin/umax according to + * information of low bits. + */ + coerce_reg_to_size(reg, 4); + /* smin/smax need special handling. For example, after coerce, + * if smin_value is 0x00000000ffffffffLL, the value is -1 when + * used as operand to JMP32. It is a negative number from s32's + * point of view, while it is a positive number when seen as + * s64. The smin/smax are kept as s64, therefore, when used with + * JMP32, they need to be transformed into s32, then sign + * extended back to s64. + * + * Also, smin/smax were copied from umin/umax. If umin/umax has + * different sign bit, then min/max relationship doesn't + * maintain after casting into s32, for this case, set smin/smax + * to safest range. + */ + if ((reg->umax_value ^ reg->umin_value) & + (1ULL << 31)) { + reg->smin_value = S32_MIN; + reg->smax_value = S32_MAX; + } + reg->smin_value = (s64)(s32)reg->smin_value; + reg->smax_value = (s64)(s32)reg->smax_value; + + val = (u32)val; + sval = (s64)(s32)val; + } else { + sval = (s64)val; + } + switch (opcode) { case BPF_JEQ: if (tnum_is_const(reg->var_off)) @@ -4058,9 +4097,9 @@ static int is_branch_taken(struct bpf_reg_state *reg, u64 val, u8 opcode) return 0; break; case BPF_JSGT: - if (reg->smin_value > (s64)val) + if (reg->smin_value > sval) return 1; - else if (reg->smax_value < (s64)val) + else if (reg->smax_value < sval) return 0; break; case BPF_JLT: @@ -4070,9 +4109,9 @@ static int is_branch_taken(struct bpf_reg_state *reg, u64 val, u8 opcode) return 0; break; case BPF_JSLT: - if (reg->smax_value < (s64)val) + if (reg->smax_value < sval) return 1; - else if (reg->smin_value >= (s64)val) + else if (reg->smin_value >= sval) return 0; break; case BPF_JGE: @@ -4082,9 +4121,9 @@ static int is_branch_taken(struct bpf_reg_state *reg, u64 val, u8 opcode) return 0; break; case BPF_JSGE: - if (reg->smin_value >= (s64)val) + if (reg->smin_value >= sval) return 1; - else if (reg->smax_value < (s64)val) + else if (reg->smax_value < sval) return 0; break; case BPF_JLE: @@ -4094,9 +4133,9 @@ static int is_branch_taken(struct bpf_reg_state *reg, u64 val, u8 opcode) return 0; break; case BPF_JSLE: - if (reg->smax_value <= (s64)val) + if (reg->smax_value <= sval) return 1; - else if (reg->smin_value > (s64)val) + else if (reg->smin_value > sval) return 0; break; } @@ -4104,6 +4143,29 @@ static int is_branch_taken(struct bpf_reg_state *reg, u64 val, u8 opcode) return -1; } +/* Generate min value of the high 32-bit from TNUM info. */ +static u64 gen_hi_min(struct tnum var) +{ + return var.value & ~0xffffffffULL; +} + +/* Generate max value of the high 32-bit from TNUM info. */ +static u64 gen_hi_max(struct tnum var) +{ + return (var.value | var.mask) & ~0xffffffffULL; +} + +/* Return true if VAL is compared with a s64 sign extended from s32, and they + * are with the same signedness. + */ +static bool cmp_val_with_extended_s64(s64 sval, struct bpf_reg_state *reg) +{ + return ((s32)sval >= 0 && + reg->smin_value >= 0 && reg->smax_value <= S32_MAX) || + ((s32)sval < 0 && + reg->smax_value <= 0 && reg->smin_value >= S32_MIN); +} + /* Adjusts the register min/max values in the case that the dst_reg is the * variable register that we are working on, and src_reg is a constant or we're * simply doing a BPF_K check. @@ -4111,8 +4173,10 @@ static int is_branch_taken(struct bpf_reg_state *reg, u64 val, u8 opcode) */ static void reg_set_min_max(struct bpf_reg_state *true_reg, struct bpf_reg_state *false_reg, u64 val, - u8 opcode) + u8 opcode, bool is_jmp32) { + s64 sval; + /* If the dst_reg is a pointer, we can't learn anything about its * variable offset from the compare (unless src_reg were a pointer into * the same object, but we don't bother with that. @@ -4122,19 +4186,31 @@ static void reg_set_min_max(struct bpf_reg_state *true_reg, if (__is_pointer_value(false, false_reg)) return; + val = is_jmp32 ? (u32)val : val; + sval = is_jmp32 ? (s64)(s32)val : (s64)val; + switch (opcode) { case BPF_JEQ: - /* If this is false then we know nothing Jon Snow, but if it is - * true then we know for sure. - */ - __mark_reg_known(true_reg, val); - break; case BPF_JNE: - /* If this is true we know nothing Jon Snow, but if it is false - * we know the value for sure; + { + struct bpf_reg_state *reg = + opcode == BPF_JEQ ? true_reg : false_reg; + + /* For BPF_JEQ, if this is false we know nothing Jon Snow, but + * if it is true we know the value for sure. Likewise for + * BPF_JNE. */ - __mark_reg_known(false_reg, val); + if (is_jmp32) { + u64 old_v = reg->var_off.value; + u64 hi_mask = ~0xffffffffULL; + + reg->var_off.value = (old_v & hi_mask) | val; + reg->var_off.mask &= hi_mask; + } else { + __mark_reg_known(reg, val); + } break; + } case BPF_JSET: false_reg->var_off = tnum_and(false_reg->var_off, tnum_const(~val)); @@ -4142,38 +4218,61 @@ static void reg_set_min_max(struct bpf_reg_state *true_reg, true_reg->var_off = tnum_or(true_reg->var_off, tnum_const(val)); break; - case BPF_JGT: - false_reg->umax_value = min(false_reg->umax_value, val); - true_reg->umin_value = max(true_reg->umin_value, val + 1); - break; - case BPF_JSGT: - false_reg->smax_value = min_t(s64, false_reg->smax_value, val); - true_reg->smin_value = max_t(s64, true_reg->smin_value, val + 1); - break; - case BPF_JLT: - false_reg->umin_value = max(false_reg->umin_value, val); - true_reg->umax_value = min(true_reg->umax_value, val - 1); - break; - case BPF_JSLT: - false_reg->smin_value = max_t(s64, false_reg->smin_value, val); - true_reg->smax_value = min_t(s64, true_reg->smax_value, val - 1); - break; case BPF_JGE: - false_reg->umax_value = min(false_reg->umax_value, val - 1); - true_reg->umin_value = max(true_reg->umin_value, val); + case BPF_JGT: + { + u64 false_umax = opcode == BPF_JGT ? val : val - 1; + u64 true_umin = opcode == BPF_JGT ? val + 1 : val; + + if (is_jmp32) { + false_umax += gen_hi_max(false_reg->var_off); + true_umin += gen_hi_min(true_reg->var_off); + } + false_reg->umax_value = min(false_reg->umax_value, false_umax); + true_reg->umin_value = max(true_reg->umin_value, true_umin); break; + } case BPF_JSGE: - false_reg->smax_value = min_t(s64, false_reg->smax_value, val - 1); - true_reg->smin_value = max_t(s64, true_reg->smin_value, val); + case BPF_JSGT: + { + s64 false_smax = opcode == BPF_JSGT ? sval : sval - 1; + s64 true_smin = opcode == BPF_JSGT ? sval + 1 : sval; + + /* If the full s64 was not sign-extended from s32 then don't + * deduct further info. + */ + if (is_jmp32 && !cmp_val_with_extended_s64(sval, false_reg)) + break; + false_reg->smax_value = min(false_reg->smax_value, false_smax); + true_reg->smin_value = max(true_reg->smin_value, true_smin); break; + } case BPF_JLE: - false_reg->umin_value = max(false_reg->umin_value, val + 1); - true_reg->umax_value = min(true_reg->umax_value, val); + case BPF_JLT: + { + u64 false_umin = opcode == BPF_JLT ? val : val + 1; + u64 true_umax = opcode == BPF_JLT ? val - 1 : val; + + if (is_jmp32) { + false_umin += gen_hi_min(false_reg->var_off); + true_umax += gen_hi_max(true_reg->var_off); + } + false_reg->umin_value = max(false_reg->umin_value, false_umin); + true_reg->umax_value = min(true_reg->umax_value, true_umax); break; + } case BPF_JSLE: - false_reg->smin_value = max_t(s64, false_reg->smin_value, val + 1); - true_reg->smax_value = min_t(s64, true_reg->smax_value, val); + case BPF_JSLT: + { + s64 false_smin = opcode == BPF_JSLT ? sval : sval + 1; + s64 true_smax = opcode == BPF_JSLT ? sval - 1 : sval; + + if (is_jmp32 && !cmp_val_with_extended_s64(sval, false_reg)) + break; + false_reg->smin_value = max(false_reg->smin_value, false_smin); + true_reg->smax_value = min(true_reg->smax_value, true_smax); break; + } default: break; } @@ -4196,24 +4295,34 @@ static void reg_set_min_max(struct bpf_reg_state *true_reg, */ static void reg_set_min_max_inv(struct bpf_reg_state *true_reg, struct bpf_reg_state *false_reg, u64 val, - u8 opcode) + u8 opcode, bool is_jmp32) { + s64 sval; + if (__is_pointer_value(false, false_reg)) return; + val = is_jmp32 ? (u32)val : val; + sval = is_jmp32 ? (s64)(s32)val : (s64)val; + switch (opcode) { case BPF_JEQ: - /* If this is false then we know nothing Jon Snow, but if it is - * true then we know for sure. - */ - __mark_reg_known(true_reg, val); - break; case BPF_JNE: - /* If this is true we know nothing Jon Snow, but if it is false - * we know the value for sure; - */ - __mark_reg_known(false_reg, val); + { + struct bpf_reg_state *reg = + opcode == BPF_JEQ ? true_reg : false_reg; + + if (is_jmp32) { + u64 old_v = reg->var_off.value; + u64 hi_mask = ~0xffffffffULL; + + reg->var_off.value = (old_v & hi_mask) | val; + reg->var_off.mask &= hi_mask; + } else { + __mark_reg_known(reg, val); + } break; + } case BPF_JSET: false_reg->var_off = tnum_and(false_reg->var_off, tnum_const(~val)); @@ -4221,38 +4330,58 @@ static void reg_set_min_max_inv(struct bpf_reg_state *true_reg, true_reg->var_off = tnum_or(true_reg->var_off, tnum_const(val)); break; - case BPF_JGT: - true_reg->umax_value = min(true_reg->umax_value, val - 1); - false_reg->umin_value = max(false_reg->umin_value, val); - break; - case BPF_JSGT: - true_reg->smax_value = min_t(s64, true_reg->smax_value, val - 1); - false_reg->smin_value = max_t(s64, false_reg->smin_value, val); - break; - case BPF_JLT: - true_reg->umin_value = max(true_reg->umin_value, val + 1); - false_reg->umax_value = min(false_reg->umax_value, val); - break; - case BPF_JSLT: - true_reg->smin_value = max_t(s64, true_reg->smin_value, val + 1); - false_reg->smax_value = min_t(s64, false_reg->smax_value, val); - break; case BPF_JGE: - true_reg-& |