diff options
| -rw-r--r-- | include/linux/bpf_verifier.h | 1 | ||||
| -rw-r--r-- | kernel/bpf/liveness.c | 56 | ||||
| -rw-r--r-- | kernel/bpf/verifier.c | 72 |
3 files changed, 58 insertions, 71 deletions
diff --git a/include/linux/bpf_verifier.h b/include/linux/bpf_verifier.h index c7515da8500c..4c497e839526 100644 --- a/include/linux/bpf_verifier.h +++ b/include/linux/bpf_verifier.h @@ -1049,6 +1049,7 @@ void print_insn_state(struct bpf_verifier_env *env, const struct bpf_verifier_st u32 frameno); struct bpf_subprog_info *bpf_find_containing_subprog(struct bpf_verifier_env *env, int off); +int bpf_jmp_offset(struct bpf_insn *insn); int bpf_insn_successors(struct bpf_prog *prog, u32 idx, u32 succ[2]); void bpf_fmt_stack_mask(char *buf, ssize_t buf_sz, u64 stack_mask); bool bpf_calls_callback(struct bpf_verifier_env *env, int insn_idx); diff --git a/kernel/bpf/liveness.c b/kernel/bpf/liveness.c index 6f9dfaaf6e64..3c611aba7f52 100644 --- a/kernel/bpf/liveness.c +++ b/kernel/bpf/liveness.c @@ -433,6 +433,62 @@ static void log_mask_change(struct bpf_verifier_env *env, struct callchain *call bpf_log(&env->log, "\n"); } +int bpf_jmp_offset(struct bpf_insn *insn) +{ + u8 code = insn->code; + + if (code == (BPF_JMP32 | BPF_JA)) + return insn->imm; + return insn->off; +} + +__diag_push(); +__diag_ignore_all("-Woverride-init", "Allow field initialization overrides for opcode_info_tbl"); + +inline int bpf_insn_successors(struct bpf_prog *prog, u32 idx, u32 succ[2]) +{ + static const struct opcode_info { + bool can_jump; + bool can_fallthrough; + } opcode_info_tbl[256] = { + [0 ... 255] = {.can_jump = false, .can_fallthrough = true}, + #define _J(code, ...) \ + [BPF_JMP | code] = __VA_ARGS__, \ + [BPF_JMP32 | code] = __VA_ARGS__ + + _J(BPF_EXIT, {.can_jump = false, .can_fallthrough = false}), + _J(BPF_JA, {.can_jump = true, .can_fallthrough = false}), + _J(BPF_JEQ, {.can_jump = true, .can_fallthrough = true}), + _J(BPF_JNE, {.can_jump = true, .can_fallthrough = true}), + _J(BPF_JLT, {.can_jump = true, .can_fallthrough = true}), + _J(BPF_JLE, {.can_jump = true, .can_fallthrough = true}), + _J(BPF_JGT, {.can_jump = true, .can_fallthrough = true}), + _J(BPF_JGE, {.can_jump = true, .can_fallthrough = true}), + _J(BPF_JSGT, {.can_jump = true, .can_fallthrough = true}), + _J(BPF_JSGE, {.can_jump = true, .can_fallthrough = true}), + _J(BPF_JSLT, {.can_jump = true, .can_fallthrough = true}), + _J(BPF_JSLE, {.can_jump = true, .can_fallthrough = true}), + _J(BPF_JCOND, {.can_jump = true, .can_fallthrough = true}), + _J(BPF_JSET, {.can_jump = true, .can_fallthrough = true}), + #undef _J + }; + struct bpf_insn *insn = &prog->insnsi[idx]; + const struct opcode_info *opcode_info; + int i = 0, insn_sz; + + opcode_info = &opcode_info_tbl[BPF_CLASS(insn->code) | BPF_OP(insn->code)]; + insn_sz = bpf_is_ldimm64(insn) ? 2 : 1; + if (opcode_info->can_fallthrough) + succ[i++] = idx + insn_sz; + + if (opcode_info->can_jump) + succ[i++] = idx + bpf_jmp_offset(insn) + 1; + + return i; +} + +__diag_pop(); + static struct func_instance *get_outer_instance(struct bpf_verifier_env *env, struct func_instance *instance) { diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index e1da2471442b..1d4183bc3cd1 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -3485,15 +3485,6 @@ static int add_subprog_and_kfunc(struct bpf_verifier_env *env) return 0; } -static int jmp_offset(struct bpf_insn *insn) -{ - u8 code = insn->code; - - if (code == (BPF_JMP32 | BPF_JA)) - return insn->imm; - return insn->off; -} - static int check_subprogs(struct bpf_verifier_env *env) { int i, subprog_start, subprog_end, off, cur_subprog = 0; @@ -3520,7 +3511,7 @@ static int check_subprogs(struct bpf_verifier_env *env) goto next; if (BPF_OP(code) == BPF_EXIT || BPF_OP(code) == BPF_CALL) goto next; - off = i + jmp_offset(&insn[i]) + 1; + off = i + bpf_jmp_offset(&insn[i]) + 1; if (off < subprog_start || off >= subprog_end) { verbose(env, "jump out of range from insn %d to %d\n", i, off); return -EINVAL; @@ -23944,67 +23935,6 @@ static int process_fd_array(struct bpf_verifier_env *env, union bpf_attr *attr, return 0; } -static bool can_fallthrough(struct bpf_insn *insn) -{ - u8 class = BPF_CLASS(insn->code); - u8 opcode = BPF_OP(insn->code); - - if (class != BPF_JMP && class != BPF_JMP32) - return true; - - if (opcode == BPF_EXIT || opcode == BPF_JA) - return false; - - return true; -} - -static bool can_jump(struct bpf_insn *insn) -{ - u8 class = BPF_CLASS(insn->code); - u8 opcode = BPF_OP(insn->code); - - if (class != BPF_JMP && class != BPF_JMP32) - return false; - - switch (opcode) { - case BPF_JA: - case BPF_JEQ: - case BPF_JNE: - case BPF_JLT: - case BPF_JLE: - case BPF_JGT: - case BPF_JGE: - case BPF_JSGT: - case BPF_JSGE: - case BPF_JSLT: - case BPF_JSLE: - case BPF_JCOND: - case BPF_JSET: - return true; - } - - return false; -} - -int bpf_insn_successors(struct bpf_prog *prog, u32 idx, u32 succ[2]) -{ - struct bpf_insn *insn = &prog->insnsi[idx]; - int i = 0, insn_sz; - u32 dst; - - insn_sz = bpf_is_ldimm64(insn) ? 2 : 1; - if (can_fallthrough(insn) && idx + 1 < prog->len) - succ[i++] = idx + insn_sz; - - if (can_jump(insn)) { - dst = idx + jmp_offset(insn) + 1; - if (i == 0 || succ[0] != dst) - succ[i++] = dst; - } - - return i; -} - /* Each field is a register bitmask */ struct insn_live_regs { u16 use; /* registers read by instruction */ |