Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next

Minor conflict, a CHECK was placed into an if() statement
in net-next, whilst a newline was added to that CHECK
call in 'net'.  Thanks to Daniel for the merge resolution.

Signed-off-by: David S. Miller <davem@davemloft.net>

10 files changed, 566 insertions, 214 deletions

diff --git a/kernel/bpf/Makefile b/kernel/bpf/Makefile
index 35c485fa9ea3..f27f5496d6fe 100644
--- a/kernel/bpf/Makefile
+++ b/kernel/bpf/Makefile
@@ -8,6 +8,9 @@ obj-$(CONFIG_BPF_SYSCALL) += btf.o
 ifeq ($(CONFIG_NET),y)
 obj-$(CONFIG_BPF_SYSCALL) += devmap.o
 obj-$(CONFIG_BPF_SYSCALL) += cpumap.o
+ifeq ($(CONFIG_XDP_SOCKETS),y)
+obj-$(CONFIG_BPF_SYSCALL) += xskmap.o
+endif
 obj-$(CONFIG_BPF_SYSCALL) += offload.o
 ifeq ($(CONFIG_STREAM_PARSER),y)
 ifeq ($(CONFIG_INET),y)
diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c
index ba03ec39efb3..d0d7d9462368 100644
--- a/kernel/bpf/core.c
+++ b/kernel/bpf/core.c
@@ -31,6 +31,7 @@
 #include <linux/rbtree_latch.h>
 #include <linux/kallsyms.h>
 #include <linux/rcupdate.h>
+#include <linux/perf_event.h>
 
 #include <asm/unaligned.h>
 
@@ -633,23 +634,6 @@ 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_LD | BPF_ABS | BPF_W:
-	case BPF_LD | BPF_ABS | BPF_H:
-	case BPF_LD | BPF_ABS | BPF_B:
-		*to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm);
-		*to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
-		*to++ = BPF_LD_IND(from->code, BPF_REG_AX, 0);
-		break;
-
-	case BPF_LD | BPF_IND | BPF_W:
-	case BPF_LD | BPF_IND | BPF_H:
-	case BPF_LD | BPF_IND | BPF_B:
-		*to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm);
-		*to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
-		*to++ = BPF_ALU32_REG(BPF_ADD, BPF_REG_AX, from->src_reg);
-		*to++ = BPF_LD_IND(from->code, BPF_REG_AX, 0);
-		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);
@@ -890,14 +874,7 @@ EXPORT_SYMBOL_GPL(__bpf_call_base);
 	INSN_3(LDX, MEM, W),			\
 	INSN_3(LDX, MEM, DW),			\
 	/*   Immediate based. */		\
-	INSN_3(LD, IMM, DW),			\
-	/*   Misc (old cBPF carry-over). */	\
-	INSN_3(LD, ABS, B),			\
-	INSN_3(LD, ABS, H),			\
-	INSN_3(LD, ABS, W),			\
-	INSN_3(LD, IND, B),			\
-	INSN_3(LD, IND, H),			\
-	INSN_3(LD, IND, W)
+	INSN_3(LD, IMM, DW)
 
 bool bpf_opcode_in_insntable(u8 code)
 {
@@ -907,6 +884,13 @@ bool bpf_opcode_in_insntable(u8 code)
 		[0 ... 255] = false,
 		/* Now overwrite non-defaults ... */
 		BPF_INSN_MAP(BPF_INSN_2_TBL, BPF_INSN_3_TBL),
+		/* UAPI exposed, but rewritten opcodes. cBPF carry-over. */
+		[BPF_LD | BPF_ABS | BPF_B] = true,
+		[BPF_LD | BPF_ABS | BPF_H] = true,
+		[BPF_LD | BPF_ABS | BPF_W] = true,
+		[BPF_LD | BPF_IND | BPF_B] = true,
+		[BPF_LD | BPF_IND | BPF_H] = true,
+		[BPF_LD | BPF_IND | BPF_W] = true,
 	};
 #undef BPF_INSN_3_TBL
 #undef BPF_INSN_2_TBL
@@ -937,8 +921,6 @@ static u64 ___bpf_prog_run(u64 *regs, const struct bpf_insn *insn, u64 *stack)
 #undef BPF_INSN_3_LBL
 #undef BPF_INSN_2_LBL
 	u32 tail_call_cnt = 0;
-	void *ptr;
-	int off;
 
 #define CONT	 ({ insn++; goto select_insn; })
 #define CONT_JMP ({ insn++; goto select_insn; })
@@ -1265,67 +1247,6 @@ out:
 		atomic64_add((u64) SRC, (atomic64_t *)(unsigned long)
 			     (DST + insn->off));
 		CONT;
-	LD_ABS_W: /* BPF_R0 = ntohl(*(u32 *) (skb->data + imm32)) */
-		off = IMM;
-load_word:
-		/* BPF_LD + BPD_ABS and BPF_LD + BPF_IND insns are only
-		 * appearing in the programs where ctx == skb
-		 * (see may_access_skb() in the verifier). All programs
-		 * keep 'ctx' in regs[BPF_REG_CTX] == BPF_R6,
-		 * bpf_convert_filter() saves it in BPF_R6, internal BPF
-		 * verifier will check that BPF_R6 == ctx.
-		 *
-		 * BPF_ABS and BPF_IND are wrappers of function calls,
-		 * so they scratch BPF_R1-BPF_R5 registers, preserve
-		 * BPF_R6-BPF_R9, and store return value into BPF_R0.
-		 *
-		 * Implicit input:
-		 *   ctx == skb == BPF_R6 == CTX
-		 *
-		 * Explicit input:
-		 *   SRC == any register
-		 *   IMM == 32-bit immediate
-		 *
-		 * Output:
-		 *   BPF_R0 - 8/16/32-bit skb data converted to cpu endianness
-		 */
-
-		ptr = bpf_load_pointer((struct sk_buff *) (unsigned long) CTX, off, 4, &tmp);
-		if (likely(ptr != NULL)) {
-			BPF_R0 = get_unaligned_be32(ptr);
-			CONT;
-		}
-
-		return 0;
-	LD_ABS_H: /* BPF_R0 = ntohs(*(u16 *) (skb->data + imm32)) */
-		off = IMM;
-load_half:
-		ptr = bpf_load_pointer((struct sk_buff *) (unsigned long) CTX, off, 2, &tmp);
-		if (likely(ptr != NULL)) {
-			BPF_R0 = get_unaligned_be16(ptr);
-			CONT;
-		}
-
-		return 0;
-	LD_ABS_B: /* BPF_R0 = *(u8 *) (skb->data + imm32) */
-		off = IMM;
-load_byte:
-		ptr = bpf_load_pointer((struct sk_buff *) (unsigned long) CTX, off, 1, &tmp);
-		if (likely(ptr != NULL)) {
-			BPF_R0 = *(u8 *)ptr;
-			CONT;
-		}
-
-		return 0;
-	LD_IND_W: /* BPF_R0 = ntohl(*(u32 *) (skb->data + src_reg + imm32)) */
-		off = IMM + SRC;
-		goto load_word;
-	LD_IND_H: /* BPF_R0 = ntohs(*(u16 *) (skb->data + src_reg + imm32)) */
-		off = IMM + SRC;
-		goto load_half;
-	LD_IND_B: /* BPF_R0 = *(u8 *) (skb->data + src_reg + imm32) */
-		off = IMM + SRC;
-		goto load_byte;
 
 	default_label:
 		/* If we ever reach this, we have a bug somewhere. Die hard here
@@ -1722,6 +1643,10 @@ static void bpf_prog_free_deferred(struct work_struct *work)
 	aux = container_of(work, struct bpf_prog_aux, work);
 	if (bpf_prog_is_dev_bound(aux))
 		bpf_prog_offload_destroy(aux->prog);
+#ifdef CONFIG_PERF_EVENTS
+	if (aux->prog->has_callchain_buf)
+		put_callchain_buffers();
+#endif
 	for (i = 0; i < aux->func_cnt; i++)
 		bpf_jit_free(aux->func[i]);
 	if (aux->func_cnt) {
@@ -1794,6 +1719,7 @@ bpf_event_output(struct bpf_map *map, u64 flags, void *meta, u64 meta_size,
 {
 	return -ENOTSUPP;
 }
+EXPORT_SYMBOL_GPL(bpf_event_output);
 
 /* Always built-in helper functions. */
 const struct bpf_func_proto bpf_tail_call_proto = {
@@ -1840,9 +1766,3 @@ int __weak skb_copy_bits(const struct sk_buff *skb, int offset, void *to,
 #include <linux/bpf_trace.h>
 
 EXPORT_TRACEPOINT_SYMBOL_GPL(xdp_exception);
-
-/* These are only used within the BPF_SYSCALL code */
-#ifdef CONFIG_BPF_SYSCALL
-EXPORT_TRACEPOINT_SYMBOL_GPL(bpf_prog_get_type);
-EXPORT_TRACEPOINT_SYMBOL_GPL(bpf_prog_put_rcu);
-#endif
diff --git a/kernel/bpf/inode.c b/kernel/bpf/inode.c
index a41343009ccc..ed13645bd80c 100644
--- a/kernel/bpf/inode.c
+++ b/kernel/bpf/inode.c
@@ -429,13 +429,6 @@ int bpf_obj_pin_user(u32 ufd, const char __user *pathname)
 	ret = bpf_obj_do_pin(pname, raw, type);
 	if (ret != 0)
 		bpf_any_put(raw, type);
-	if ((trace_bpf_obj_pin_prog_enabled() ||
-	     trace_bpf_obj_pin_map_enabled()) && !ret) {
-		if (type == BPF_TYPE_PROG)
-			trace_bpf_obj_pin_prog(raw, ufd, pname);
-		if (type == BPF_TYPE_MAP)
-			trace_bpf_obj_pin_map(raw, ufd, pname);
-	}
 out:
 	putname(pname);
 	return ret;
@@ -502,15 +495,8 @@ int bpf_obj_get_user(const char __user *pathname, int flags)
 	else
 		goto out;
 
-	if (ret < 0) {
+	if (ret < 0)
 		bpf_any_put(raw, type);
-	} else if (trace_bpf_obj_get_prog_enabled() ||
-		   trace_bpf_obj_get_map_enabled()) {
-		if (type == BPF_TYPE_PROG)
-			trace_bpf_obj_get_prog(raw, ret, pname);
-		if (type == BPF_TYPE_MAP)
-			trace_bpf_obj_get_map(raw, ret, pname);
-	}
 out:
 	putname(pname);
 	return ret;
diff --git a/kernel/bpf/offload.c b/kernel/bpf/offload.c
index c9401075b58c..ac747d5cf7c6 100644
--- a/kernel/bpf/offload.c
+++ b/kernel/bpf/offload.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2017 Netronome Systems, Inc.
+ * Copyright (C) 2017-2018 Netronome Systems, Inc.
  *
  * This software is licensed under the GNU General License Version 2,
  * June 1991 as shown in the file COPYING in the top-level directory of this
@@ -474,8 +474,10 @@ bool bpf_offload_dev_match(struct bpf_prog *prog, struct bpf_map *map)
 	struct bpf_prog_offload *offload;
 	bool ret;
 
-	if (!bpf_prog_is_dev_bound(prog->aux) || !bpf_map_is_dev_bound(map))
+	if (!bpf_prog_is_dev_bound(prog->aux))
 		return false;
+	if (!bpf_map_is_dev_bound(map))
+		return bpf_map_offload_neutral(map);
 
 	down_read(&bpf_devs_lock);
 	offload = prog->aux->offload;
diff --git a/kernel/bpf/stackmap.c b/kernel/bpf/stackmap.c
index 57eeb1234b67..3ba102b41512 100644
--- a/kernel/bpf/stackmap.c
+++ b/kernel/bpf/stackmap.c
@@ -262,16 +262,11 @@ out:
 	return ret;
 }
 
-static void stack_map_get_build_id_offset(struct bpf_map *map,
-					  struct stack_map_bucket *bucket,
+static void stack_map_get_build_id_offset(struct bpf_stack_build_id *id_offs,
 					  u64 *ips, u32 trace_nr, bool user)
 {
 	int i;
 	struct vm_area_struct *vma;
-	struct bpf_stack_build_id *id_offs;
-
-	bucket->nr = trace_nr;
-	id_offs = (struct bpf_stack_build_id *)bucket->data;
 
 	/*
 	 * We cannot do up_read() in nmi context, so build_id lookup is
@@ -361,8 +356,10 @@ BPF_CALL_3(bpf_get_stackid, struct pt_regs *, regs, struct bpf_map *, map,
 			pcpu_freelist_pop(&smap->freelist);
 		if (unlikely(!new_bucket))
 			return -ENOMEM;
-		stack_map_get_build_id_offset(map, new_bucket, ips,
-					      trace_nr, user);
+		new_bucket->nr = trace_nr;
+		stack_map_get_build_id_offset(
+			(struct bpf_stack_build_id *)new_bucket->data,
+			ips, trace_nr, user);
 		trace_len = trace_nr * sizeof(struct bpf_stack_build_id);
 		if (hash_matches && bucket->nr == trace_nr &&
 		    memcmp(bucket->data, new_bucket->data, trace_len) == 0) {
@@ -405,6 +402,73 @@ const struct bpf_func_proto bpf_get_stackid_proto = {
 	.arg3_type	= ARG_ANYTHING,
 };
 
+BPF_CALL_4(bpf_get_stack, struct pt_regs *, regs, void *, buf, u32, size,
+	   u64, flags)
+{
+	u32 init_nr, trace_nr, copy_len, elem_size, num_elem;
+	bool user_build_id = flags & BPF_F_USER_BUILD_ID;
+	u32 skip = flags & BPF_F_SKIP_FIELD_MASK;
+	bool user = flags & BPF_F_USER_STACK;
+	struct perf_callchain_entry *trace;
+	bool kernel = !user;
+	int err = -EINVAL;
+	u64 *ips;
+
+	if (unlikely(flags & ~(BPF_F_SKIP_FIELD_MASK | BPF_F_USER_STACK |
+			       BPF_F_USER_BUILD_ID)))
+		goto clear;
+	if (kernel && user_build_id)
+		goto clear;
+
+	elem_size = (user && user_build_id) ? sizeof(struct bpf_stack_build_id)
+					    : sizeof(u64);
+	if (unlikely(size % elem_size))
+		goto clear;
+
+	num_elem = size / elem_size;
+	if (sysctl_perf_event_max_stack < num_elem)
+		init_nr = 0;
+	else
+		init_nr = sysctl_perf_event_max_stack - num_elem;
+	trace = get_perf_callchain(regs, init_nr, kernel, user,
+				   sysctl_perf_event_max_stack, false, false);
+	if (unlikely(!trace))
+		goto err_fault;
+
+	trace_nr = trace->nr - init_nr;
+	if (trace_nr < skip)
+		goto err_fault;
+
+	trace_nr -= skip;
+	trace_nr = (trace_nr <= num_elem) ? trace_nr : num_elem;
+	copy_len = trace_nr * elem_size;
+	ips = trace->ip + skip + init_nr;
+	if (user && user_build_id)
+		stack_map_get_build_id_offset(buf, ips, trace_nr, user);
+	else
+		memcpy(buf, ips, copy_len);
+
+	if (size > copy_len)
+		memset(buf + copy_len, 0, size - copy_len);
+	return copy_len;
+
+err_fault:
+	err = -EFAULT;
+clear:
+	memset(buf, 0, size);
+	return err;
+}
+
+const struct bpf_func_proto bpf_get_stack_proto = {
+	.func		= bpf_get_stack,
+	.gpl_only	= true,
+	.ret_type	= RET_INTEGER,
+	.arg1_type	= ARG_PTR_TO_CTX,
+	.arg2_type	= ARG_PTR_TO_UNINIT_MEM,
+	.arg3_type	= ARG_CONST_SIZE_OR_ZERO,
+	.arg4_type	= ARG_ANYTHING,
+};
+
 /* Called from eBPF program */
 static void *stack_map_lookup_elem(struct bpf_map *map, void *key)
 {
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index 0bd2944eafb9..9b87198deea2 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -282,6 +282,7 @@ void bpf_map_put(struct bpf_map *map)
 {
 	__bpf_map_put(map, true);
 }
+EXPORT_SYMBOL_GPL(bpf_map_put);
 
 void bpf_map_put_with_uref(struct bpf_map *map)
 {
@@ -503,7 +504,6 @@ static int map_create(union bpf_attr *attr)
 		return err;
 	}
 
-	trace_bpf_map_create(map, err);
 	return err;
 
 free_map:
@@ -544,6 +544,7 @@ struct bpf_map *bpf_map_inc(struct bpf_map *map, bool uref)
 		atomic_inc(&map->usercnt);
 	return map;
 }
+EXPORT_SYMBOL_GPL(bpf_map_inc);
 
 struct bpf_map *bpf_map_get_with_uref(u32 ufd)
 {
@@ -663,7 +664,6 @@ static int map_lookup_elem(union bpf_attr *attr)
 	if (copy_to_user(uvalue, value, value_size) != 0)
 		goto free_value;
 
-	trace_bpf_map_lookup_elem(map, ufd, key, value);
 	err = 0;
 
 free_value:
@@ -760,8 +760,6 @@ static int map_update_elem(union bpf_attr *attr)
 	__this_cpu_dec(bpf_prog_active);
 	preempt_enable();
 out:
-	if (!err)
-		trace_bpf_map_update_elem(map, ufd, key, value);
 free_value:
 	kfree(value);
 free_key:
@@ -814,8 +812,6 @@ static int map_delete_elem(union bpf_attr *attr)
 	__this_cpu_dec(bpf_prog_active);
 	preempt_enable();
 out:
-	if (!err)
-		trace_bpf_map_delete_elem(map, ufd, key);
 	kfree(key);
 err_put:
 	fdput(f);
@@ -879,7 +875,6 @@ out:
 	if (copy_to_user(unext_key, next_key, map->key_size) != 0)
 		goto free_next_key;
 
-	trace_bpf_map_next_key(map, ufd, key, next_key);
 	err = 0;
 
 free_next_key:
@@ -1027,7 +1022,6 @@ static void __bpf_prog_put(struct bpf_prog *prog, bool do_idr_lock)
 	if (atomic_dec_and_test(&prog->aux->refcnt)) {
 		int i;
 
-		trace_bpf_prog_put_rcu(prog);
 		/* bpf_prog_free_id() must be called first */
 		bpf_prog_free_id(prog, do_idr_lock);
 
@@ -1194,11 +1188,7 @@ struct bpf_prog *bpf_prog_get(u32 ufd)
 struct bpf_prog *bpf_prog_get_type_dev(u32 ufd, enum bpf_prog_type type,
 				       bool attach_drv)
 {
-	struct bpf_prog *prog = __bpf_prog_get(ufd, &type, attach_drv);
-
-	if (!IS_ERR(prog))
-		trace_bpf_prog_get_type(prog);
-	return prog;
+	return __bpf_prog_get(ufd, &type, attach_drv);
 }
 EXPORT_SYMBOL_GPL(bpf_prog_get_type_dev);
 
@@ -1373,7 +1363,6 @@ static int bpf_prog_load(union bpf_attr *attr)
 	}
 
 	bpf_prog_kallsyms_add(prog);
-	trace_bpf_prog_load(prog, err);
 	return err;
 
 free_used_maps:
diff --git a/kernel/bpf/tnum.c b/kernel/bpf/tnum.c
index 1f4bf68c12db..938d41211be7 100644
--- a/kernel/bpf/tnum.c
+++ b/kernel/bpf/tnum.c
@@ -43,6 +43,16 @@ struct tnum tnum_rshift(struct tnum a, u8 shift)
 	return TNUM(a.value >> shift, a.mask >> shift);
 }
 
+struct tnum tnum_arshift(struct tnum a, u8 min_shift)
+{
+	/* if a.value is negative, arithmetic shifting by minimum shift
+	 * will have larger negative offset compared to more shifting.
+	 * If a.value is nonnegative, arithmetic shifting by minimum shift
+	 * will have larger positive offset compare to more shifting.
+	 */
+	return TNUM((s64)a.value >> min_shift, (s64)a.mask >> min_shift);
+}
+
 struct tnum tnum_add(struct tnum a, struct tnum b)
 {
 	u64 sm, sv, sigma, chi, mu;
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index eb1a596aebd3..d5e1a6c4165d 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -22,6 +22,7 @@
 #include <linux/stringify.h>
 #include <linux/bsearch.h>
 #include <linux/sort.h>
+#include <linux/perf_event.h>
 
 #include "disasm.h"
 
@@ -164,6 +165,8 @@ struct bpf_call_arg_meta {
 	bool pkt_access;
 	int regno;
 	int access_size;
+	s64 msize_smax_value;
+	u64 msize_umax_value;
 };
 
 static DEFINE_MUTEX(bpf_verifier_lock);
@@ -738,18 +741,19 @@ enum reg_arg_type {
 
 static int cmp_subprogs(const void *a, const void *b)
 {
-	return *(int *)a - *(int *)b;
+	return ((struct bpf_subprog_info *)a)->start -
+	       ((struct bpf_subprog_info *)b)->start;
 }
 
 static int find_subprog(struct bpf_verifier_env *env, int off)
 {
-	u32 *p;
+	struct bpf_subprog_info *p;
 
-	p = bsearch(&off, env->subprog_starts, env->subprog_cnt,
-		    sizeof(env->subprog_starts[0]), cmp_subprogs);
+	p = bsearch(&off, env->subprog_info, env->subprog_cnt,
+		    sizeof(env->subprog_info[0]), cmp_subprogs);
 	if (!p)
 		return -ENOENT;
-	return p - env->subprog_starts;
+	return p - env->subprog_info;
 
 }
 
@@ -769,18 +773,24 @@ static int add_subprog(struct bpf_verifier_env *env, int off)
 		verbose(env, "too many subprograms\n");
 		return -E2BIG;
 	}
-	env->subprog_starts[env->subprog_cnt++] = off;
-	sort(env->subprog_starts, env->subprog_cnt,
-	     sizeof(env->subprog_starts[0]), cmp_subprogs, NULL);
+	env->subprog_info[env->subprog_cnt++].start = off;
+	sort(env->subprog_info, env->subprog_cnt,
+	     sizeof(env->subprog_info[0]), cmp_subprogs, NULL);
 	return 0;
 }
 
 static int check_subprogs(struct bpf_verifier_env *env)
 {
 	int i, ret, subprog_start, subprog_end, off, cur_subprog = 0;
+	struct bpf_subprog_info *subprog = env->subprog_info;
 	struct bpf_insn *insn = env->prog->insnsi;
 	int insn_cnt = env->prog->len;
 
+	/* Add entry function. */
+	ret = add_subprog(env, 0);
+	if (ret < 0)
+		return ret;
+
 	/* determine subprog starts. The end is one before the next starts */
 	for (i = 0; i < insn_cnt; i++) {
 		if (insn[i].code != (BPF_JMP | BPF_CALL))
@@ -800,16 +810,18 @@ static int check_subprogs(struct bpf_verifier_env *env)
 			return ret;
 	}
 
+	/* Add a fake 'exit' subprog which could simplify subprog iteration
+	 * logic. 'subprog_cnt' should not be increased.
+	 */
+	subprog[env->subprog_cnt].start = insn_cnt;
+
 	if (env->log.level > 1)
 		for (i = 0; i < env->subprog_cnt; i++)
-			verbose(env, "func#%d @%d\n", i, env->subprog_starts[i]);
+			verbose(env, "func#%d @%d\n", i, subprog[i].start);
 
 	/* now check that all jumps are within the same subprog */
-	subprog_start = 0;
-	if (env->subprog_cnt == cur_subprog)
-		subprog_end = insn_cnt;
-	else
-		subprog_end = env->subprog_starts[cur_subprog++];
+	subprog_start = subprog[cur_subprog].start;
+	subprog_end = subprog[cur_subprog + 1].start;
 	for (i = 0; i < insn_cnt; i++) {
 		u8 code = insn[i].code;
 
@@ -834,10 +846,9 @@ next:
 				return -EINVAL;
 			}
 			subprog_start = subprog_end;
-			if (env->subprog_cnt == cur_subprog)
-				subprog_end = insn_cnt;
-			else
-				subprog_end = env->subprog_starts[cur_subprog++];
+			cur_subprog++;
+			if (cur_subprog < env->subprog_cnt)
+				subprog_end = subprog[cur_subprog + 1].start;
 		}
 	}
 	return 0;
@@ -1470,13 +1481,13 @@ static int update_stack_depth(struct bpf_verifier_env *env,
 			      const struct bpf_func_state *func,
 			      int off)
 {
-	u16 stack = env->subprog_stack_depth[func->subprogno];
+	u16 stack = env->subprog_info[func->subprogno].stack_depth;
 
 	if (stack >= -off)
 		return 0;
 
 	/* update known max for given subprogram */
-	env->subprog_stack_depth[func->subprogno] = -off;
+	env->subprog_info[func->subprogno].stack_depth = -off;
 	return 0;
 }
 
@@ -1488,9 +1499,9 @@ static int update_stack_depth(struct bpf_verifier_env *env,
  */
 static int check_max_stack_depth(struct bpf_verifier_env *env)
 {
-	int depth = 0, frame = 0, subprog = 0, i = 0, subprog_end;
+	int depth = 0, frame = 0, idx = 0, i = 0, subprog_end;
+	struct bpf_subprog_info *subprog = env->subprog_info;
 	struct bpf_insn *insn = env->prog->insnsi;
-	int insn_cnt = env->prog->len;
 	int ret_insn[MAX_CALL_FRAMES];
 	int ret_prog[MAX_CALL_FRAMES];
 
@@ -1498,17 +1509,14 @@ process_func:
 	/* round up to 32-bytes, since this is granularity
 	 * of interpreter stack size
 	 */
-	depth += round_up(max_t(u32, env->subprog_stack_depth[subprog], 1), 32);
+	depth += round_up(max_t(u32, subprog[idx].stack_depth, 1), 32);
 	if (depth > MAX_BPF_STACK) {
 		verbose(env, "combined stack size of %d calls is %d. Too large\n",
 			frame + 1, depth);
 		return -EACCES;
 	}
 continue_func:
-	if (env->subprog_cnt == subprog)
-		subprog_end = insn_cnt;
-	else
-		subprog_end = env->subprog_starts[subprog];
+	subprog_end = subprog[idx + 1].start;
 	for (; i < subprog_end; i++) {
 		if (insn[i].code != (BPF_JMP | BPF_CALL))
 			continue;
@@ -1516,17 +1524,16 @@ continue_func:
 			continue;
 		/* remember insn and function to return to */
 		ret_insn[frame] = i + 1;
-		ret_prog[frame] = subprog;
+		ret_prog[frame] = idx;
 
 		/* find the callee */
 		i = i + insn[i].imm + 1;
-		subprog = find_subprog(env, i);
-		if (subprog < 0) {
+		idx = find_subprog(env, i);
+		if (idx < 0) {
 			WARN_ONCE(1, "verifier bug. No program starts at insn %d\n",
 				  i);
 			return -EFAULT;
 		}
-		subprog++;
 		frame++;
 		if (frame >= MAX_CALL_FRAMES) {
 			WARN_ONCE(1, "verifier bug. Call stack is too deep\n");
@@ -1539,10 +1546,10 @@ continue_func:
 	 */
 	if (frame == 0)
 		return 0;
-	depth -= round_up(max_t(u32, env->subprog_stack_depth[subprog], 1), 32);
+	depth -= round_up(max_t(u32, subprog[idx].stack_depth, 1), 32);
 	frame--;
 	i = ret_insn[frame];
-	subprog = ret_prog[frame];
+	idx = ret_prog[frame];
 	goto continue_func;
 }
 
@@ -1558,8 +1565,7 @@ static int get_callee_stack_depth(struct bpf_verifier_env *env,
 			  start);
 		return -EFAULT;
 	}
-	subprog++;
-	return env->subprog_stack_depth[subprog];
+	return env->subprog_info[subprog].stack_depth;
 }
 #endif
 
@@ -1984,6 +1990,12 @@ static int check_func_arg(struct bpf_verifier_env *env, u32 regno,
 	} else if (arg_type_is_mem_size(arg_type)) {
 		bool zero_size_allowed = (arg_type == ARG_CONST_SIZE_OR_ZERO);
 
+		/* remember the mem_size which may be used later
+		 * to refine return values.
+		 */
+		meta->msize_smax_value = reg->smax_value;
+		meta->msize_umax_value = reg->umax_value;
+
 		/* The register is SCALAR_VALUE; the access check
 		 * happens using its boundaries.
 		 */
@@ -2061,8 +2073,11 @@ static int check_map_func_compatibility(struct bpf_verifier_env *env,
 		if (func_id != BPF_FUNC_redirect_map)
 			goto error;
 		break;
-	/* Restrict bpf side of cpumap, open when use-cases appear */
+	/* Restrict bpf side of cpumap and xskmap, open when use-cases
+	 * appear.
+	 */
 	case BPF_MAP_TYPE_CPUMAP:
+	case BPF_MAP_TYPE_XSKMAP:
 		if (func_id != BPF_FUNC_redirect_map)
 			goto error;
 		break;
@@ -2087,7 +2102,7 @@ static int check_map_func_compatibility(struct bpf_verifier_env *env,
 	case BPF_FUNC_tail_call:
 		if (map->map_type != BPF_MAP_TYPE_PROG_ARRAY)
 			goto error;
-		if (env->subprog_cnt) {
+		if (env->subprog_cnt > 1) {
 			verbose(env, "tail_calls are not allowed in programs with bpf-to-bpf calls\n");
 			return -EINVAL;
 		}
@@ -2109,7 +2124,8 @@ static int check_map_func_compatibility(struct bpf_verifier_env *env,
 		break;
 	case BPF_FUNC_redirect_map:
 		if (map->map_type != BPF_MAP_TYPE_DEVMAP &&
-		    map->map_type != BPF_MAP_TYPE_CPUMAP)
+		    map->map_type != BPF_MAP_TYPE_CPUMAP &&
+		    map->map_type != BPF_MAP_TYPE_XSKMAP)
 			goto error;
 		break;
 	case BPF_FUNC_sk_redirect_map:
@@ -2259,7 +2275,7 @@ static int check_func_call(struct bpf_verifier_env *env, struct bpf_insn *insn,
 			/* remember the callsite, it will be used by bpf_exit */
 			*insn_idx /* callsite */,
 			state->curframe + 1 /* frameno within this callchain */,
-			subprog + 1 /* subprog number within this prog */);
+			subprog /* subprog number within this prog */);
 
 	/* copy r1 - r5 args that callee can access */
 	for (i = BPF_REG_1; i <= BPF_REG_5; i++)
@@ -2323,6 +2339,23 @@ static int prepare_func_exit(struct bpf_verifier_env *env, int *insn_idx)
 	return 0;
 }
 
+static void do_refine_retval_range(struct bpf_reg_state *regs, int ret_type,
+				   int func_id,
+				   struct bpf_call_arg_meta *meta)
+{
+	struct bpf_reg_state *ret_reg = &regs[BPF_REG_0];
+
+	if (ret_type != RET_INTEGER ||
+	    (func_id != BPF_FUNC_get_stack &&
+	     func_id != BPF_FUNC_probe_read_str))
+		return;
+
+	ret_reg->smax_value = meta->msize_smax_value;
+	ret_reg->umax_value = meta->msize_umax_value;
+	__reg_deduce_bounds(ret_reg);
+	__reg_bound_offset(ret_reg);
+}
+
 static int check_helper_call(struct bpf_verifier_env *env, int func_id, int insn_idx)
 {
 	const struct bpf_func_proto *fn = NULL;
@@ -2446,10 +2479,30 @@ static int check_helper_call(struct bpf_verifier_env *env, int func_id, int insn
 		return -EINVAL;
 	}
 
+	do_refine_retval_range(regs, fn->ret_type, func_id, &meta);
+
 	err = check_map_func_compatibility(env, meta.map_ptr, func_id);
 	if (err)
 		return err;
 
+	if (func_id == BPF_FUNC_get_stack && !env->prog->has_callchain_buf) {
+		const char *err_str;
+
+#ifdef CONFIG_PERF_EVENTS
+		err = get_callchain_buffers(sysctl_perf_event_max_stack);
+		err_str = "cannot get callchain buffer for func %s#%d\n";
+#else
+		err = -ENOTSUPP;
+		err_str = "func %s#%d not supported without CONFIG_PERF_EVENTS\n";
+#endif
+		if (err) {
+			verbose(env, err_str, func_id_name(func_id), func_id);
+			return err;
+		}
+
+		env->prog->has_callchain_buf = true;
+	}
+
 	if (changes_data)
 		clear_all_pkt_pointers(env);
 	return 0;
@@ -2894,10 +2947,7 @@ static int adjust_scalar_min_max_vals(struct bpf_verifier_env *env,
 			dst_reg->umin_value <<= umin_val;
 			dst_reg->umax_value <<= umax_val;
 		}
-		if (src_known)
-			dst_reg->var_off = tnum_lshift(dst_reg->var_off, umin_val);
-		else
-			dst_reg->var_off = tnum_lshift(tnum_unknown, umin_val);
+		dst_reg->var_off = tnum_lshift(dst_reg->var_off, umin_val);
 		/* We may learn something more from the var_off */
 		__update_reg_bounds(dst_reg);
 		break;
@@ -2925,16 +2975,35 @@ static int adjust_scalar_min_max_vals(struct bpf_verifier_env *env,
 		 */
 		dst_reg->smin_value = S64_MIN;
 		dst_reg->smax_value = S64_MAX;
-		if (src_known)
-			dst_reg->var_off = tnum_rshift(dst_reg->var_off,
-						       umin_val);
-		else
-			dst_reg->var_off = tnum_rshift(tnum_unknown, umin_val);
+		dst_reg->var_off = tnum_rshift(dst_reg->var_off, umin_val);
 		dst_reg->umin_value >>= umax_val;
 		dst_reg->umax_value >>= umin_val;
 		/* We may learn something more from the var_off */
 		__update_reg_bounds(dst_reg);
 		break;
+	case BPF_ARSH:
+		if (umax_val >= insn_bitness) {
+			/* Shifts greater than 31 or 63 are undefined.
+			 * This includes shifts by a negative number.
+			 */
+			mark_reg_unknown(env, regs, insn->dst_reg);
+			break;
+		}
+
+		/* Upon reaching here, src_known is true and
+		 * umax_val is equal to umin_val.
+		 */
+		dst_reg->smin_value >>= umin_val;
+		dst_reg->smax_value >>= umin_val;
+		dst_reg->var_off = tnum_arshift(dst_reg->var_off, umin_val);
+
+		/* blow away the dst_reg umin_value/umax_value and rely on
+		 * dst_reg var_off to refine the result.
+		 */
+		dst_reg->umin_value = 0;
+		dst_reg->umax_value = U64_MAX;
+		__update_reg_bounds(dst_reg);
+		break;
 	default:
 		mark_reg_unknown(env, regs, insn->dst_reg);
 		break;
@@ -3818,7 +3887,12 @@ static int check_ld_abs(struct bpf_verifier_env *env, struct bpf_insn *insn)
 		return -EINVAL;
 	}
 
-	if (env->subprog_cnt) {
+	if (!env->ops->gen_ld_abs) {
+		verbose(env, "bpf verifier is misconfigured\n");
+		return -EINVAL;
+	}
+
+	if (env->subprog_cnt > 1) {
 		/* when program has LD_ABS insn JITs and interpreter assume
 		 * that r1 == ctx == skb which is not the case for callees
 		 * that can have arbitrary arguments. It's problematic
@@ -4849,15 +4923,15 @@ process_bpf_exit:
 
 	verbose(env, "processed %d insns (limit %d), stack depth ",
 		insn_processed, BPF_COMPLEXITY_LIMIT_INSNS);
-	for (i = 0; i < env->subprog_cnt + 1; i++) {
-		u32 depth = env->subprog_stack_depth[i];
+	for (i = 0; i < env->subprog_cnt; i++) {
+		u32 depth = env->subprog_info[i].stack_depth;
 
 		verbose(env, "%d", depth);
-		if (i + 1 < env->subprog_cnt + 1)
+		if (i + 1 < env->subprog_cnt)
 			verbose(env, "+");
 	}
 	verbose(env, "\n");
-	env->prog->aux->stack_depth = env->subprog_stack_depth[0];
+	env->prog->aux->stack_depth = env->subprog_info[0].stack_depth;
 	return 0;
 }
 
@@ -4981,7 +5055,7 @@ static int replace_map_fd_with_map_ptr(struct bpf_verifier_env *env)
 			/* hold the map. If the program is rejected by verifier,
 			 * the map will be released by release_maps() or it
 			 * will be used by the valid program until it's unloaded
-			 * and all maps are released in free_bpf_prog_info()
+			 * and all maps are released in free_used_maps()
 			 */
 			map = bpf_map_inc(map, false);
 			if (IS_ERR(map)) {
@@ -5063,10 +5137,11 @@ static void adjust_subprog_starts(struct bpf_verifier_env *env, u32 off, u32 len
 
 	if (len == 1)
 		return;
-	for (i = 0; i < env->subprog_cnt; i++) {
-		if (env->subprog_starts[i] < off)
+	/* NOTE: fake 'exit' subprog should be updated as well. */
+	for (i = 0; i <= env->subprog_cnt; i++) {
+		if (env->subprog_info[i].start < off)
 			continue;
-		env->subprog_starts[i] += len - 1;
+		env->subprog_info[i].start += len - 1;
 	}
 }
 
@@ -5230,7 +5305,7 @@ static int jit_subprogs(struct bpf_verifier_env *env)
 	void *old_bpf_func;
 	int err = -ENOMEM;
 
-	if (env->subprog_cnt == 0)
+	if (env->subprog_cnt <= 1)
 		return 0;
 
 	for (i = 0, insn = prog->insnsi; i < prog->len; i++, insn++) {
@@ -5246,7 +5321,7 @@ static int jit_subprogs(struct bpf_verifier_env *env)
 		/* temporarily remember subprog id inside insn instead of
 		 * aux_data, since next loop will split up all insns into funcs
 		 */
-		insn->off = subprog + 1;
+		insn->off = subprog;
 		/* remember original imm in case JIT fails and fallback
 		 * to interpreter will be needed
 		 */
@@ -5255,16 +5330,13 @@ static int jit_subprogs(struct bpf_verifier_env *env)
 		insn->imm = 1;
 	}
 
-	func = kzalloc(sizeof(prog) * (env->subprog_cnt + 1), GFP_KERNEL);
+	func = kzalloc(sizeof(prog) * env->subprog_cnt, GFP_KERNEL);
 	if (!func)
 		return -ENOMEM;
 
-	for (i = 0; i <= env->subprog_cnt; i++) {
+	for (i = 0; i < env->subprog_cnt; i++) {
 		subprog_start = subprog_end;
-		if (env->subprog_cnt == i)
-			subprog_end = prog->len;
-		else
-			subprog_end = env->subprog_starts[i];
+		subprog_end = env->subprog_info[i + 1].start;
 
 		len = subprog_end - subprog_start;
 		func[i] = bpf_prog_alloc(bpf_prog_size(len), GFP_USER);
@@ -5281,7 +5353,7 @@ static int jit_subprogs(struct bpf_verifier_env *env)
 		 * Long term would need debug info to populate names
 		 */
 		func[i]->aux->name[0] = 'F';
-		func[i]->aux->stack_depth = env->subprog_stack_depth[i];
+		func[i]->aux->stack_depth = env->subprog_info[i].stack_depth;
 		func[i]->jit_requested = 1;
 		func[i] = bpf_int_jit_compile(func[i]);
 		if (!func[i]->jited) {
@@ -5294,7 +5366,7 @@ static int jit_subprogs(struct bpf_verifier_env *env)
 	 * now populate all bpf_calls with correct addresses and
 	 * run last pass of JIT
 	 */
-	for (i = 0; i <= env->subprog_cnt; i++) {
+	for (i = 0; i < env->subprog_cnt; i++) {
 		insn = func[i]->insnsi;
 		for (j = 0; j < func[i]->len; j++, insn++) {
 			if (insn->code != (BPF_JMP | BPF_CALL) ||
@@ -5307,7 +5379,7 @@ static int jit_subprogs(struct bpf_verifier_env *env)
 				__bpf_call_base;
 		}
 	}
-	for (i = 0; i <= env->subprog_cnt; i++) {
+	for (i = 0; i < env->subprog_cnt; i++) {
 		old_bpf_func = func[i]->bpf_func;
 		tmp = bpf_int_jit_compile(func[i]);
 		if (tmp != func[i] || func[i]->bpf_func != old_bpf_func) {
@@ -5321,7 +5393,7 @@ static int jit_subprogs(struct bp