diff options
Diffstat (limited to 'include/linux/bpf_verifier.h')
| -rw-r--r-- | include/linux/bpf_verifier.h | 45 |
1 files changed, 41 insertions, 4 deletions
diff --git a/include/linux/bpf_verifier.h b/include/linux/bpf_verifier.h index c561b986bab0..aaac589e490c 100644 --- a/include/linux/bpf_verifier.h +++ b/include/linux/bpf_verifier.h @@ -76,6 +76,14 @@ struct bpf_reg_state { s64 smax_value; /* maximum possible (s64)value */ u64 umin_value; /* minimum possible (u64)value */ u64 umax_value; /* maximum possible (u64)value */ + /* Inside the callee two registers can be both PTR_TO_STACK like + * R1=fp-8 and R2=fp-8, but one of them points to this function stack + * while another to the caller's stack. To differentiate them 'frameno' + * is used which is an index in bpf_verifier_state->frame[] array + * pointing to bpf_func_state. + * This field must be second to last, for states_equal() reasons. + */ + u32 frameno; /* This field must be last, for states_equal() reasons. */ enum bpf_reg_liveness live; }; @@ -83,7 +91,8 @@ struct bpf_reg_state { enum bpf_stack_slot_type { STACK_INVALID, /* nothing was stored in this stack slot */ STACK_SPILL, /* register spilled into stack */ - STACK_MISC /* BPF program wrote some data into this slot */ + STACK_MISC, /* BPF program wrote some data into this slot */ + STACK_ZERO, /* BPF program wrote constant zero */ }; #define BPF_REG_SIZE 8 /* size of eBPF register in bytes */ @@ -96,13 +105,34 @@ struct bpf_stack_state { /* state of the program: * type of all registers and stack info */ -struct bpf_verifier_state { +struct bpf_func_state { struct bpf_reg_state regs[MAX_BPF_REG]; struct bpf_verifier_state *parent; + /* index of call instruction that called into this func */ + int callsite; + /* stack frame number of this function state from pov of + * enclosing bpf_verifier_state. + * 0 = main function, 1 = first callee. + */ + u32 frameno; + /* subprog number == index within subprog_stack_depth + * zero == main subprog + */ + u32 subprogno; + + /* should be second to last. See copy_func_state() */ int allocated_stack; struct bpf_stack_state *stack; }; +#define MAX_CALL_FRAMES 8 +struct bpf_verifier_state { + /* call stack tracking */ + struct bpf_func_state *frame[MAX_CALL_FRAMES]; + struct bpf_verifier_state *parent; + u32 curframe; +}; + /* linked list of verifier states used to prune search */ struct bpf_verifier_state_list { struct bpf_verifier_state state; @@ -113,6 +143,7 @@ struct bpf_insn_aux_data { union { enum bpf_reg_type ptr_type; /* pointer type for load/store insns */ struct bpf_map *map_ptr; /* pointer for call insn into lookup_elem */ + s32 call_imm; /* saved imm field of call insn */ }; int ctx_field_size; /* the ctx field size for load insn, maybe 0 */ bool seen; /* this insn was processed by the verifier */ @@ -141,6 +172,8 @@ struct bpf_ext_analyzer_ops { int insn_idx, int prev_insn_idx); }; +#define BPF_MAX_SUBPROGS 256 + /* single container for all structs * one verifier_env per bpf_check() call */ @@ -159,13 +192,17 @@ struct bpf_verifier_env { bool allow_ptr_leaks; bool seen_direct_write; struct bpf_insn_aux_data *insn_aux_data; /* array of per-insn state */ - struct bpf_verifer_log log; + u32 subprog_starts[BPF_MAX_SUBPROGS]; + u16 subprog_stack_depth[BPF_MAX_SUBPROGS + 1]; + u32 subprog_cnt; }; static inline struct bpf_reg_state *cur_regs(struct bpf_verifier_env *env) { - return env->cur_state->regs; + struct bpf_verifier_state *cur = env->cur_state; + + return cur->frame[cur->curframe]->regs; } #if defined(CONFIG_NET) && defined(CONFIG_BPF_SYSCALL) |