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-rw-r--r--include/linux/bpf_verifier.h63
1 files changed, 46 insertions, 17 deletions
diff --git a/include/linux/bpf_verifier.h b/include/linux/bpf_verifier.h
index 1632bb1..6b66cd1 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 */
@@ -135,11 +166,7 @@ static inline bool bpf_verifier_log_full(const struct bpf_verifer_log *log)
return log->len_used >= log->len_total - 1;
}
-struct bpf_verifier_env;
-struct bpf_ext_analyzer_ops {
- int (*insn_hook)(struct bpf_verifier_env *env,
- int insn_idx, int prev_insn_idx);
-};
+#define BPF_MAX_SUBPROGS 256
/* single container for all structs
* one verifier_env per bpf_check() call
@@ -152,29 +179,31 @@ struct bpf_verifier_env {
bool strict_alignment; /* perform strict pointer alignment checks */
struct bpf_verifier_state *cur_state; /* current verifier state */
struct bpf_verifier_state_list **explored_states; /* search pruning optimization */
- const struct bpf_ext_analyzer_ops *dev_ops; /* device analyzer ops */
struct bpf_map *used_maps[MAX_USED_MAPS]; /* array of map's used by eBPF program */
u32 used_map_cnt; /* number of used maps */
u32 id_gen; /* used to generate unique reg IDs */
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];
+ /* computes the stack depth of each bpf function */
+ u16 subprog_stack_depth[BPF_MAX_SUBPROGS + 1];
+ u32 subprog_cnt;
};
+__printf(2, 3) void bpf_verifier_log_write(struct bpf_verifier_env *env,
+ const char *fmt, ...);
+
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)
int bpf_prog_offload_verifier_prep(struct bpf_verifier_env *env);
-#else
-static inline int bpf_prog_offload_verifier_prep(struct bpf_verifier_env *env)
-{
- return -EOPNOTSUPP;
-}
-#endif
+int bpf_prog_offload_verify_insn(struct bpf_verifier_env *env,
+ int insn_idx, int prev_insn_idx);
#endif /* _LINUX_BPF_VERIFIER_H */
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