3 files changed, 56 insertions, 6 deletions
diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index 54dc7cae2949..da54ef644fcd 100644
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -200,6 +200,9 @@ struct bpf_prog_aux {
 	u32 max_ctx_offset;
 	u32 stack_depth;
 	u32 id;
+	u32 func_cnt;
+	struct bpf_prog **func;
+	void *jit_data; /* JIT specific data. arch dependent */
 	struct latch_tree_node ksym_tnode;
 	struct list_head ksym_lnode;
 	const struct bpf_prog_ops *ops;
@@ -402,6 +405,7 @@ static inline void bpf_long_memcpy(void *dst, const void *src, u32 size)
 
 /* verify correctness of eBPF program */
 int bpf_check(struct bpf_prog **fp, union bpf_attr *attr);
+void bpf_patch_call_args(struct bpf_insn *insn, u32 stack_depth);
 
 /* Map specifics */
 struct net_device  *__dev_map_lookup_elem(struct bpf_map *map, u32 key);
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)
diff --git a/include/linux/filter.h b/include/linux/filter.h
index 5feb441d3dd9..e872b4ebaa57 100644
--- a/include/linux/filter.h
+++ b/include/linux/filter.h
@@ -58,6 +58,9 @@ struct bpf_prog_aux;
 /* unused opcode to mark special call to bpf_tail_call() helper */
 #define BPF_TAIL_CALL	0xf0
 
+/* unused opcode to mark call to interpreter with arguments */
+#define BPF_CALL_ARGS	0xe0
+
 /* As per nm, we expose JITed images as text (code) section for
  * kallsyms. That way, tools like perf can find it to match
  * addresses.
@@ -455,10 +458,13 @@ struct bpf_binary_header {
 struct bpf_prog {
 	u16			pages;		/* Number of allocated pages */
 	u16			jited:1,	/* Is our filter JIT'ed? */
+				jit_requested:1,/* archs need to JIT the prog */
 				locked:1,	/* Program image locked? */
 				gpl_compatible:1, /* Is filter GPL compatible? */
 				cb_access:1,	/* Is control block accessed? */
 				dst_needed:1,	/* Do we need dst entry? */
+				blinded:1,	/* Was blinded */
+				is_func:1,	/* program is a bpf function */
 				kprobe_override:1; /* Do we override a kprobe? */
 	enum bpf_prog_type	type;		/* Type of BPF program */
 	u32			len;		/* Number of filter blocks */
@@ -710,6 +716,9 @@ bool sk_filter_charge(struct sock *sk, struct sk_filter *fp);
 void sk_filter_uncharge(struct sock *sk, struct sk_filter *fp);
 
 u64 __bpf_call_base(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5);
+#define __bpf_call_base_args \
+	((u64 (*)(u64, u64, u64, u64, u64, const struct bpf_insn *)) \
+	 __bpf_call_base)
 
 struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog);
 void bpf_jit_compile(struct bpf_prog *prog);
@@ -798,7 +807,7 @@ static inline bool bpf_prog_ebpf_jited(const struct bpf_prog *fp)
 	return fp->jited && bpf_jit_is_ebpf();
 }
 
-static inline bool bpf_jit_blinding_enabled(void)
+static inline bool bpf_jit_blinding_enabled(struct bpf_prog *prog)
 {
 	/* These are the prerequisites, should someone ever have the
 	 * idea to call blinding outside of them, we make sure to
@@ -806,7 +815,7 @@ static inline bool bpf_jit_blinding_enabled(void)
 	 */
 	if (!bpf_jit_is_ebpf())
 		return false;
-	if (!bpf_jit_enable)
+	if (!prog->jit_requested)
 		return false;
 	if (!bpf_jit_harden)
 		return false;