diff --git a/include/linux/bpf_verifier.h b/include/linux/bpf_verifier.h
index 5406e6e..6abd5a7 100644
--- a/include/linux/bpf_verifier.h
+++ b/include/linux/bpf_verifier.h
@@ -123,6 +123,10 @@ 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 */
+	s32 s32_min_value; /* minimum possible (s32)value */
+	s32 s32_max_value; /* maximum possible (s32)value */
+	u32 u32_min_value; /* minimum possible (u32)value */
+	u32 u32_max_value; /* maximum possible (u32)value */
 	/* parentage chain for liveness checking */
 	struct bpf_reg_state *parent;
 	/* Inside the callee two registers can be both PTR_TO_STACK like
diff --git a/include/linux/limits.h b/include/linux/limits.h
index 76afcd2..0d3de82 100644
--- a/include/linux/limits.h
+++ b/include/linux/limits.h
@@ -27,6 +27,7 @@
 #define S16_MAX		((s16)(U16_MAX >> 1))
 #define S16_MIN		((s16)(-S16_MAX - 1))
 #define U32_MAX		((u32)~0U)
+#define U32_MIN		((u32)0)
 #define S32_MAX		((s32)(U32_MAX >> 1))
 #define S32_MIN		((s32)(-S32_MAX - 1))
 #define U64_MAX		((u64)~0ULL)
diff --git a/include/linux/tnum.h b/include/linux/tnum.h
index ea627d1..498dbce 100644
--- a/include/linux/tnum.h
+++ b/include/linux/tnum.h
@@ -86,4 +86,16 @@ int tnum_strn(char *str, size_t size, struct tnum a);
 /* Format a tnum as tristate binary expansion */
 int tnum_sbin(char *str, size_t size, struct tnum a);
 
+/* Returns the 32-bit subreg */
+struct tnum tnum_subreg(struct tnum a);
+/* Returns the tnum with the lower 32-bit subreg cleared */
+struct tnum tnum_clear_subreg(struct tnum a);
+/* Returns the tnum with the lower 32-bit subreg set to value */
+struct tnum tnum_const_subreg(struct tnum a, u32 value);
+/* Returns true if 32-bit subreg @a is a known constant*/
+static inline bool tnum_subreg_is_const(struct tnum a)
+{
+	return !(tnum_subreg(a)).mask;
+}
+
 #endif /* _LINUX_TNUM_H */
diff --git a/kernel/bpf/tnum.c b/kernel/bpf/tnum.c
index d4f335a..ceac528 100644
--- a/kernel/bpf/tnum.c
+++ b/kernel/bpf/tnum.c
@@ -194,3 +194,18 @@ int tnum_sbin(char *str, size_t size, struct tnum a)
 	str[min(size - 1, (size_t)64)] = 0;
 	return 64;
 }
+
+struct tnum tnum_subreg(struct tnum a)
+{
+	return tnum_cast(a, 4);
+}
+
+struct tnum tnum_clear_subreg(struct tnum a)
+{
+	return tnum_lshift(tnum_rshift(a, 32), 32);
+}
+
+struct tnum tnum_const_subreg(struct tnum a, u32 value)
+{
+	return tnum_or(tnum_clear_subreg(a), tnum_const(value));
+}
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index dda3b94..804a39a 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -550,6 +550,22 @@ static void print_verifier_state(struct bpf_verifier_env *env,
 					tnum_strn(tn_buf, sizeof(tn_buf), reg->var_off);
 					verbose(env, ",var_off=%s", tn_buf);
 				}
+				if (reg->s32_min_value != reg->smin_value &&
+				    reg->s32_min_value != S32_MIN)
+					verbose(env, ",s32_min_value=%d",
+						(int)(reg->s32_min_value));
+				if (reg->s32_max_value != reg->smax_value &&
+				    reg->s32_max_value != S32_MAX)
+					verbose(env, ",s32_max_value=%d",
+						(int)(reg->s32_max_value));
+				if (reg->u32_min_value != reg->umin_value &&
+				    reg->u32_min_value != U32_MIN)
+					verbose(env, ",u32_min_value=%d",
+						(int)(reg->u32_min_value));
+				if (reg->u32_max_value != reg->umax_value &&
+				    reg->u32_max_value != U32_MAX)
+					verbose(env, ",u32_max_value=%d",
+						(int)(reg->u32_max_value));
 			}
 			verbose(env, ")");
 		}
@@ -924,6 +940,20 @@ static void __mark_reg_known(struct bpf_reg_state *reg, u64 imm)
 	reg->smax_value = (s64)imm;
 	reg->umin_value = imm;
 	reg->umax_value = imm;
+
+	reg->s32_min_value = (s32)imm;
+	reg->s32_max_value = (s32)imm;
+	reg->u32_min_value = (u32)imm;
+	reg->u32_max_value = (u32)imm;
+}
+
+static void __mark_reg32_known(struct bpf_reg_state *reg, u64 imm)
+{
+	reg->var_off = tnum_const_subreg(reg->var_off, imm);
+	reg->s32_min_value = (s32)imm;
+	reg->s32_max_value = (s32)imm;
+	reg->u32_min_value = (u32)imm;
+	reg->u32_max_value = (u32)imm;
 }
 
 /* Mark the 'variable offset' part of a register as zero.  This should be
@@ -978,8 +1008,52 @@ static bool reg_is_init_pkt_pointer(const struct bpf_reg_state *reg,
 	       tnum_equals_const(reg->var_off, 0);
 }
 
-/* Attempts to improve min/max values based on var_off information */
-static void __update_reg_bounds(struct bpf_reg_state *reg)
+/* Reset the min/max bounds of a register */
+static void __mark_reg_unbounded(struct bpf_reg_state *reg)
+{
+	reg->smin_value = S64_MIN;
+	reg->smax_value = S64_MAX;
+	reg->umin_value = 0;
+	reg->umax_value = U64_MAX;
+
+	reg->s32_min_value = S32_MIN;
+	reg->s32_max_value = S32_MAX;
+	reg->u32_min_value = 0;
+	reg->u32_max_value = U32_MAX;
+}
+
+static void __mark_reg64_unbounded(struct bpf_reg_state *reg)
+{
+	reg->smin_value = S64_MIN;
+	reg->smax_value = S64_MAX;
+	reg->umin_value = 0;
+	reg->umax_value = U64_MAX;
+}
+
+static void __mark_reg32_unbounded(struct bpf_reg_state *reg)
+{
+	reg->s32_min_value = S32_MIN;
+	reg->s32_max_value = S32_MAX;
+	reg->u32_min_value = 0;
+	reg->u32_max_value = U32_MAX;
+}
+
+static void __update_reg32_bounds(struct bpf_reg_state *reg)
+{
+	struct tnum var32_off = tnum_subreg(reg->var_off);
+
+	/* min signed is max(sign bit) | min(other bits) */
+	reg->s32_min_value = max_t(s32, reg->s32_min_value,
+			var32_off.value | (var32_off.mask & S32_MIN));
+	/* max signed is min(sign bit) | max(other bits) */
+	reg->s32_max_value = min_t(s32, reg->s32_max_value,
+			var32_off.value | (var32_off.mask & S32_MAX));
+	reg->u32_min_value = max_t(u32, reg->u32_min_value, (u32)var32_off.value);
+	reg->u32_max_value = min(reg->u32_max_value,
+				 (u32)(var32_off.value | var32_off.mask));
+}
+
+static void __update_reg64_bounds(struct bpf_reg_state *reg)
 {
 	/* min signed is max(sign bit) | min(other bits) */
 	reg->smin_value = max_t(s64, reg->smin_value,
@@ -992,8 +1066,48 @@ static void __update_reg_bounds(struct bpf_reg_state *reg)
 			      reg->var_off.value | reg->var_off.mask);
 }
 
+static void __update_reg_bounds(struct bpf_reg_state *reg)
+{
+	__update_reg32_bounds(reg);
+	__update_reg64_bounds(reg);
+}
+
 /* Uses signed min/max values to inform unsigned, and vice-versa */
-static void __reg_deduce_bounds(struct bpf_reg_state *reg)
+static void __reg32_deduce_bounds(struct bpf_reg_state *reg)
+{
+	/* Learn sign from signed bounds.
+	 * If we cannot cross the sign boundary, then signed and unsigned bounds
+	 * are the same, so combine.  This works even in the negative case, e.g.
+	 * -3 s<= x s<= -1 implies 0xf...fd u<= x u<= 0xf...ff.
+	 */
+	if (reg->s32_min_value >= 0 || reg->s32_max_value < 0) {
+		reg->s32_min_value = reg->u32_min_value =
+			max_t(u32, reg->s32_min_value, reg->u32_min_value);
+		reg->s32_max_value = reg->u32_max_value =
+			min_t(u32, reg->s32_max_value, reg->u32_max_value);
+		return;
+	}
+	/* Learn sign from unsigned bounds.  Signed bounds cross the sign
+	 * boundary, so we must be careful.
+	 */
+	if ((s32)reg->u32_max_value >= 0) {
+		/* Positive.  We can't learn anything from the smin, but smax
+		 * is positive, hence safe.
+		 */
+		reg->s32_min_value = reg->u32_min_value;
+		reg->s32_max_value = reg->u32_max_value =
+			min_t(u32, reg->s32_max_value, reg->u32_max_value);
+	} else if ((s32)reg->u32_min_value < 0) {
+		/* Negative.  We can't learn anything from the smax, but smin
+		 * is negative, hence safe.
+		 */
+		reg->s32_min_value = reg->u32_min_value =
+			max_t(u32, reg->s32_min_value, reg->u32_min_value);
+		reg->s32_max_value = reg->u32_max_value;
+	}
+}
+
+static void __reg64_deduce_bounds(struct bpf_reg_state *reg)
 {
 	/* Learn sign from signed bounds.
 	 * If we cannot cross the sign boundary, then signed and unsigned bounds
@@ -1027,21 +1141,106 @@ static void __reg_deduce_bounds(struct bpf_reg_state *reg)
 	}
 }
 
+static void __reg_deduce_bounds(struct bpf_reg_state *reg)
+{
+	__reg32_deduce_bounds(reg);
+	__reg64_deduce_bounds(reg);
+}
+
 /* Attempts to improve var_off based on unsigned min/max information */
 static void __reg_bound_offset(struct bpf_reg_state *reg)
 {
-	reg->var_off = tnum_intersect(reg->var_off,
-				      tnum_range(reg->umin_value,
-						 reg->umax_value));
+	struct tnum var64_off = tnum_intersect(reg->var_off,
+					       tnum_range(reg->umin_value,
+							  reg->umax_value));
+	struct tnum var32_off = tnum_intersect(tnum_subreg(reg->var_off),
+						tnum_range(reg->u32_min_value,
+							   reg->u32_max_value));
+
+	reg->var_off = tnum_or(tnum_clear_subreg(var64_off), var32_off);
 }
 
-/* Reset the min/max bounds of a register */
-static void __mark_reg_unbounded(struct bpf_reg_state *reg)
+static void __reg_assign_32_into_64(struct bpf_reg_state *reg)
 {
-	reg->smin_value = S64_MIN;
-	reg->smax_value = S64_MAX;
-	reg->umin_value = 0;
-	reg->umax_value = U64_MAX;
+	reg->umin_value = reg->u32_min_value;
+	reg->umax_value = reg->u32_max_value;
+	/* Attempt to pull 32-bit signed bounds into 64-bit bounds
+	 * but must be positive otherwise set to worse case bounds
+	 * and refine later from tnum.
+	 */
+	if (reg->s32_min_value > 0)
+		reg->smin_value = reg->s32_min_value;
+	else
+		reg->smin_value = 0;
+	if (reg->s32_max_value > 0)
+		reg->smax_value = reg->s32_max_value;
+	else
+		reg->smax_value = U32_MAX;
+}
+
+static void __reg_combine_32_into_64(struct bpf_reg_state *reg)
+{
+	/* special case when 64-bit register has upper 32-bit register
+	 * zeroed. Typically happens after zext or <<32, >>32 sequence
+	 * allowing us to use 32-bit bounds directly,
+	 */
+	if (tnum_equals_const(tnum_clear_subreg(reg->var_off), 0)) {
+		__reg_assign_32_into_64(reg);
+	} else {
+		/* Otherwise the best we can do is push lower 32bit known and
+		 * unknown bits into register (var_off set from jmp logic)
+		 * then learn as much as possible from the 64-bit tnum
+		 * known and unknown bits. The previous smin/smax bounds are
+		 * invalid here because of jmp32 compare so mark them unknown
+		 * so they do not impact tnum bounds calculation.
+		 */
+		__mark_reg64_unbounded(reg);
+		__update_reg_bounds(reg);
+	}
+
+	/* Intersecting with the old var_off might have improved our bounds
+	 * slightly.  e.g. if umax was 0x7f...f and var_off was (0; 0xf...fc),
+	 * then new var_off is (0; 0x7f...fc) which improves our umax.
+	 */
+	__reg_deduce_bounds(reg);
+	__reg_bound_offset(reg);
+	__update_reg_bounds(reg);
+}
+
+static bool __reg64_bound_s32(s64 a)
+{
+	if (a > S32_MIN && a < S32_MAX)
+		return true;
+	return false;
+}
+
+static bool __reg64_bound_u32(u64 a)
+{
+	if (a > U32_MIN && a < U32_MAX)
+		return true;
+	return false;
+}
+
+static void __reg_combine_64_into_32(struct bpf_reg_state *reg)
+{
+	__mark_reg32_unbounded(reg);
+
+	if (__reg64_bound_s32(reg->smin_value))
+		reg->s32_min_value = (s32)reg->smin_value;
+	if (__reg64_bound_s32(reg->smax_value))
+		reg->s32_max_value = (s32)reg->smax_value;
+	if (__reg64_bound_u32(reg->umin_value))
+		reg->u32_min_value = (u32)reg->umin_value;
+	if (__reg64_bound_u32(reg->umax_value))
+		reg->u32_max_value = (u32)reg->umax_value;
+
+	/* Intersecting with the old var_off might have improved our bounds
+	 * slightly.  e.g. if umax was 0x7f...f and var_off was (0; 0xf...fc),
+	 * then new var_off is (0; 0x7f...fc) which improves our umax.
+	 */
+	__reg_deduce_bounds(reg);
+	__reg_bound_offset(reg);
+	__update_reg_bounds(reg);
 }
 
 /* Mark a register as having a completely unknown (scalar) value. */
@@ -2774,6 +2973,12 @@ static int check_tp_buffer_access(struct bpf_verifier_env *env,
 	return 0;
 }
 
+/* BPF architecture zero extends alu32 ops into 64-bit registesr */
+static void zext_32_to_64(struct bpf_reg_state *reg)
+{
+	reg->var_off = tnum_subreg(reg->var_off);
+	__reg_assign_32_into_64(reg);
+}
 
 /* truncate register to smaller size (in bytes)
  * must be called with size < BPF_REG_SIZE
@@ -2796,6 +3001,14 @@ static void coerce_reg_to_size(struct bpf_reg_state *reg, int size)
 	}
 	reg->smin_value = reg->umin_value;
 	reg->smax_value = reg->umax_value;
+
+	/* If size is smaller than 32bit register the 32bit register
+	 * values are also truncated so we push 64-bit bounds into
+	 * 32-bit bounds. Above were truncated < 32-bits already.
+	 */
+	if (size >= 4)
+		return;
+	__reg_combine_64_into_32(reg);
 }
 
 static bool bpf_map_is_rdonly(const struct bpf_map *map)
@@ -4431,7 +4644,17 @@ static bool signed_add_overflows(s64 a, s64 b)
 	return res < a;
 }
 
-static bool signed_sub_overflows(s64 a, s64 b)
+static bool signed_add32_overflows(s64 a, s64 b)
+{
+	/* Do the add in u32, where overflow is well-defined */
+	s32 res = (s32)((u32)a + (u32)b);
+
+	if (b < 0)
+		return res > a;
+	return res < a;
+}
+
+static bool signed_sub_overflows(s32 a, s32 b)
 {
 	/* Do the sub in u64, where overflow is well-defined */
 	s64 res = (s64)((u64)a - (u64)b);
@@ -4441,6 +4664,16 @@ static bool signed_sub_overflows(s64 a, s64 b)
 	return res > a;
 }
 
+static bool signed_sub32_overflows(s32 a, s32 b)
+{
+	/* Do the sub in u64, where overflow is well-defined */
+	s32 res = (s32)((u32)a - (u32)b);
+
+	if (b < 0)
+		return res < a;
+	return res > a;
+}
+
 static bool check_reg_sane_offset(struct bpf_verifier_env *env,
 				  const struct bpf_reg_state *reg,
 				  enum bpf_reg_type type)
@@ -4677,6 +4910,9 @@ static int adjust_ptr_min_max_vals(struct bpf_verifier_env *env,
 	    !check_reg_sane_offset(env, ptr_reg, ptr_reg->type))
 		return -EINVAL;
 
+	/* pointer types do not carry 32-bit bounds at the moment. */
+	__mark_reg32_unbounded(dst_reg);
+
 	switch (opcode) {
 	case BPF_ADD:
 		ret = sanitize_ptr_alu(env, insn, ptr_reg, dst_reg, smin_val < 0);
@@ -4840,6 +5076,32 @@ static int adjust_ptr_min_max_vals(struct bpf_verifier_env *env,
 	return 0;
 }
 
+static void scalar32_min_max_add(struct bpf_reg_state *dst_reg,
+				 struct bpf_reg_state *src_reg)
+{
+	s32 smin_val = src_reg->s32_min_value;
+	s32 smax_val = src_reg->s32_max_value;
+	u32 umin_val = src_reg->u32_min_value;
+	u32 umax_val = src_reg->u32_max_value;
+
+	if (signed_add32_overflows(dst_reg->s32_min_value, smin_val) ||
+	    signed_add32_overflows(dst_reg->s32_max_value, smax_val)) {
+		dst_reg->s32_min_value = S32_MIN;
+		dst_reg->s32_max_value = S32_MAX;
+	} else {
+		dst_reg->s32_min_value += smin_val;
+		dst_reg->s32_max_value += smax_val;
+	}
+	if (dst_reg->u32_min_value + umin_val < umin_val ||
+	    dst_reg->u32_max_value + umax_val < umax_val) {
+		dst_reg->u32_min_value = 0;
+		dst_reg->u32_max_value = U32_MAX;
+	} else {
+		dst_reg->u32_min_value += umin_val;
+		dst_reg->u32_max_value += umax_val;
+	}
+}
+
 static void scalar_min_max_add(struct bpf_reg_state *dst_reg,
 			       struct bpf_reg_state *src_reg)
 {
@@ -4864,7 +5126,34 @@ static void scalar_min_max_add(struct bpf_reg_state *dst_reg,
 		dst_reg->umin_value += umin_val;
 		dst_reg->umax_value += umax_val;
 	}
-	dst_reg->var_off = tnum_add(dst_reg->var_off, src_reg->var_off);
+}
+
+static void scalar32_min_max_sub(struct bpf_reg_state *dst_reg,
+				 struct bpf_reg_state *src_reg)
+{
+	s32 smin_val = src_reg->s32_min_value;
+	s32 smax_val = src_reg->s32_max_value;
+	u32 umin_val = src_reg->u32_min_value;
+	u32 umax_val = src_reg->u32_max_value;
+
+	if (signed_sub32_overflows(dst_reg->s32_min_value, smax_val) ||
+	    signed_sub32_overflows(dst_reg->s32_max_value, smin_val)) {
+		/* Overflow possible, we know nothing */
+		dst_reg->s32_min_value = S32_MIN;
+		dst_reg->s32_max_value = S32_MAX;
+	} else {
+		dst_reg->s32_min_value -= smax_val;
+		dst_reg->s32_max_value -= smin_val;
+	}
+	if (dst_reg->u32_min_value < umax_val) {
+		/* Overflow possible, we know nothing */
+		dst_reg->u32_min_value = 0;
+		dst_reg->u32_max_value = U32_MAX;
+	} else {
+		/* Cannot overflow (as long as bounds are consistent) */
+		dst_reg->u32_min_value -= umax_val;
+		dst_reg->u32_max_value -= umin_val;
+	}
 }
 
 static void scalar_min_max_sub(struct bpf_reg_state *dst_reg,
@@ -4893,7 +5182,38 @@ static void scalar_min_max_sub(struct bpf_reg_state *dst_reg,
 		dst_reg->umin_value -= umax_val;
 		dst_reg->umax_value -= umin_val;
 	}
-	dst_reg->var_off = tnum_sub(dst_reg->var_off, src_reg->var_off);
+}
+
+static void scalar32_min_max_mul(struct bpf_reg_state *dst_reg,
+				 struct bpf_reg_state *src_reg)
+{
+	s32 smin_val = src_reg->s32_min_value;
+	u32 umin_val = src_reg->u32_min_value;
+	u32 umax_val = src_reg->u32_max_value;
+
+	if (smin_val < 0 || dst_reg->s32_min_value < 0) {
+		/* Ain't nobody got time to multiply that sign */
+		__mark_reg32_unbounded(dst_reg);
+		return;
+	}
+	/* Both values are positive, so we can work with unsigned and
+	 * copy the result to signed (unless it exceeds S32_MAX).
+	 */
+	if (umax_val > U16_MAX || dst_reg->u32_max_value > U16_MAX) {
+		/* Potential overflow, we know nothing */
+		__mark_reg32_unbounded(dst_reg);
+		return;
+	}
+	dst_reg->u32_min_value *= umin_val;
+	dst_reg->u32_max_value *= umax_val;
+	if (dst_reg->u32_max_value > S32_MAX) {
+		/* Overflow possible, we know nothing */
+		dst_reg->s32_min_value = S32_MIN;
+		dst_reg->s32_max_value = S32_MAX;
+	} else {
+		dst_reg->s32_min_value = dst_reg->u32_min_value;
+		dst_reg->s32_max_value = dst_reg->u32_max_value;
+	}
 }
 
 static void scalar_min_max_mul(struct bpf_reg_state *dst_reg,
@@ -4903,11 +5223,9 @@ static void scalar_min_max_mul(struct bpf_reg_state *dst_reg,
 	u64 umin_val = src_reg->umin_value;
 	u64 umax_val = src_reg->umax_value;
 
-	dst_reg->var_off = tnum_mul(dst_reg->var_off, src_reg->var_off);
 	if (smin_val < 0 || dst_reg->smin_value < 0) {
 		/* Ain't nobody got time to multiply that sign */
-		__mark_reg_unbounded(dst_reg);
-		__update_reg_bounds(dst_reg);
+		__mark_reg64_unbounded(dst_reg);
 		return;
 	}
 	/* Both values are positive, so we can work with unsigned and
@@ -4915,9 +5233,7 @@ static void scalar_min_max_mul(struct bpf_reg_state *dst_reg,
 	 */
 	if (umax_val > U32_MAX || dst_reg->umax_value > U32_MAX) {
 		/* Potential overflow, we know nothing */
-		__mark_reg_unbounded(dst_reg);
-		/* (except what we can learn from the var_off) */
-		__update_reg_bounds(dst_reg);
+		__mark_reg64_unbounded(dst_reg);
 		return;
 	}
 	dst_reg->umin_value *= umin_val;
@@ -4932,16 +5248,59 @@ static void scalar_min_max_mul(struct bpf_reg_state *dst_reg,
 	}
 }
 
+static void scalar32_min_max_and(struct bpf_reg_state *dst_reg,
+				 struct bpf_reg_state *src_reg)
+{
+	bool src_known = tnum_subreg_is_const(src_reg->var_off);
+	bool dst_known = tnum_subreg_is_const(dst_reg->var_off);
+	struct tnum var32_off = tnum_subreg(dst_reg->var_off);
+	s32 smin_val = src_reg->s32_min_value;
+	u32 umax_val = src_reg->u32_max_value;
+
+	/* Assuming scalar64_min_max_and will be called so its safe
+	 * to skip updating register for known 32-bit case.
+	 */
+	if (src_known && dst_known)
+		return;
+
+	/* We get our minimum from the var_off, since that's inherently
+	 * bitwise.  Our maximum is the minimum of the operands' maxima.
+	 */
+	dst_reg->u32_min_value = var32_off.value;
+	dst_reg->u32_max_value = min(dst_reg->u32_max_value, umax_val);
+	if (dst_reg->s32_min_value < 0 || smin_val < 0) {
+		/* Lose signed bounds when ANDing negative numbers,
+		 * ain't nobody got time for that.
+		 */
+		dst_reg->s32_min_value = S32_MIN;
+		dst_reg->s32_max_value = S32_MAX;
+	} else {
+		/* ANDing two positives gives a positive, so safe to
+		 * cast result into s64.
+		 */
+		dst_reg->s32_min_value = dst_reg->u32_min_value;
+		dst_reg->s32_max_value = dst_reg->u32_max_value;
+	}
+
+}
+
 static void scalar_min_max_and(struct bpf_reg_state *dst_reg,
 			       struct bpf_reg_state *src_reg)
 {
+	bool src_known = tnum_is_const(src_reg->var_off);
+	bool dst_known = tnum_is_const(dst_reg->var_off);
 	s64 smin_val = src_reg->smin_value;
 	u64 umax_val = src_reg->umax_value;
 
+	if (src_known && dst_known) {
+		__mark_reg_known(dst_reg, dst_reg->var_off.value &
+					  src_reg->var_off.value);
+		return;
+	}
+
 	/* We get our minimum from the var_off, since that's inherently
 	 * bitwise.  Our maximum is the minimum of the operands' maxima.
 	 */
-	dst_reg->var_off = tnum_and(dst_reg->var_off, src_reg->var_off);
 	dst_reg->umin_value = dst_reg->var_off.value;
 	dst_reg->umax_value = min(dst_reg->umax_value, umax_val);
 	if (dst_reg->smin_value < 0 || smin_val < 0) {
@@ -4961,16 +5320,58 @@ static void scalar_min_max_and(struct bpf_reg_state *dst_reg,
 	__update_reg_bounds(dst_reg);
 }
 
+static void scalar32_min_max_or(struct bpf_reg_state *dst_reg,
+				struct bpf_reg_state *src_reg)
+{
+	bool src_known = tnum_subreg_is_const(src_reg->var_off);
+	bool dst_known = tnum_subreg_is_const(dst_reg->var_off);
+	struct tnum var32_off = tnum_subreg(dst_reg->var_off);
+	s32 smin_val = src_reg->smin_value;
+	u32 umin_val = src_reg->umin_value;
+
+	/* Assuming scalar64_min_max_or will be called so it is safe
+	 * to skip updating register for known case.
+	 */
+	if (src_known && dst_known)
+		return;
+
+	/* We get our maximum from the var_off, and our minimum is the
+	 * maximum of the operands' minima
+	 */
+	dst_reg->u32_min_value = max(dst_reg->u32_min_value, umin_val);
+	dst_reg->u32_max_value = var32_off.value | var32_off.mask;
+	if (dst_reg->s32_min_value < 0 || smin_val < 0) {
+		/* Lose signed bounds when ORing negative numbers,
+		 * ain't nobody got time for that.
+		 */
+		dst_reg->s32_min_value = S32_MIN;
+		dst_reg->s32_max_value = S32_MAX;
+	} else {
+		/* ORing two positives gives a positive, so safe to
+		 * cast result into s64.
+		 */
+		dst_reg->s32_min_value = dst_reg->umin_value;
+		dst_reg->s32_max_value = dst_reg->umax_value;
+	}
+}
+
 static void scalar_min_max_or(struct bpf_reg_state *dst_reg,
 			      struct bpf_reg_state *src_reg)
 {
+	bool src_known = tnum_is_const(src_reg->var_off);
+	bool dst_known = tnum_is_const(dst_reg->var_off);
 	s64 smin_val = src_reg->smin_value;
 	u64 umin_val = src_reg->umin_value;
 
+	if (src_known && dst_known) {
+		__mark_reg_known(dst_reg, dst_reg->var_off.value |
+					  src_reg->var_off.value);
+		return;
+	}
+
 	/* We get our maximum from the var_off, and our minimum is the
 	 * maximum of the operands' minima
 	 */
-	dst_reg->var_off = tnum_or(dst_reg->var_off, src_reg->var_off);
 	dst_reg->umin_value = max(dst_reg->umin_value, umin_val);
 	dst_reg->umax_value = dst_reg->var_off.value | dst_reg->var_off.mask;
 	if (dst_reg->smin_value < 0 || smin_val < 0) {
@@ -4990,17 +5391,62 @@ static void scalar_min_max_or(struct bpf_reg_state *dst_reg,
 	__update_reg_bounds(dst_reg);
 }
 
-static void scalar_min_max_lsh(struct bpf_reg_state *dst_reg,
-			       struct bpf_reg_state *src_reg)
+static void __scalar32_min_max_lsh(struct bpf_reg_state *dst_reg,
+				   u64 umin_val, u64 umax_val)
 {
-	u64 umax_val = src_reg->umax_value;
-	u64 umin_val = src_reg->umin_value;
-
 	/* We lose all sign bit information (except what we can pick
 	 * up from var_off)
 	 */
-	dst_reg->smin_value = S64_MIN;
-	dst_reg->smax_value = S64_MAX;
+	dst_reg->s32_min_value = S32_MIN;
+	dst_reg->s32_max_value = S32_MAX;
+	/* If we might shift our top bit out, then we know nothing */
+	if (umax_val > 31 || dst_reg->u32_max_value > 1ULL << (31 - umax_val)) {
+		dst_reg->u32_min_value = 0;
+		dst_reg->u32_max_value = U32_MAX;
+	} else {
+		dst_reg->u32_min_value <<= umin_val;
+		dst_reg->u32_max_value <<= umax_val;
+	}
+}
+
+static void scalar32_min_max_lsh(struct bpf_reg_state *dst_reg,
+				 struct bpf_reg_state *src_reg)
+{
+	u32 umax_val = src_reg->u32_max_value;
+	u32 umin_val = src_reg->u32_min_value;
+	/* u32 alu operation will zext upper bits */
+	struct tnum subreg = tnum_subreg(dst_reg->var_off);
+
+	__scalar32_min_max_lsh(dst_reg, umin_val, umax_val);
+	dst_reg->var_off = tnum_subreg(tnum_lshift(subreg, umin_val));
+	/* Not required but being careful mark reg64 bounds as unknown so
+	 * that we are forced to pick them up from tnum and zext later and
+	 * if some path skips this step we are still safe.
+	 */
+	__mark_reg64_unbounded(dst_reg);
+	__update_reg32_bounds(dst_reg);
+}
+
+static void __scalar64_min_max_lsh(struct bpf_reg_state *dst_reg,
+				   u64 umin_val, u64 umax_val)
+{
+	/* Special case <<32 because it is a common compiler pattern to zero
+	 * upper bits by doing <<32 s>>32. In this case if 32bit bounds are
+	 * positive we know this shift will also be positive so we can track
+	 * bounds correctly. Otherwise we lose all sign bit information except
+	 * what we can pick up from var_off. Perhaps we can generalize this
+	 * later to shifts of any length.
+	 */
+	if (umin_val == 32 && umax_val == 32 && dst_reg->s32_max_value >= 0)
+		dst_reg->smax_value = (s64)dst_reg->s32_max_value << 32;
+	else
+		dst_reg->smax_value = S64_MAX;
+
+	if (umin_val == 32 && umax_val == 32 && dst_reg->s32_min_value >= 0)
+		dst_reg->smin_value = (s64)dst_reg->s32_min_value << 32;
+	else
+		dst_reg->smin_value = S64_MIN;
+
 	/* If we might shift our top bit out, then we know nothing */
 	if (dst_reg->umax_value > 1ULL << (63 - umax_val)) {
 		dst_reg->umin_value = 0;
@@ -5009,11 +5455,55 @@ static void scalar_min_max_lsh(struct bpf_reg_state *dst_reg,
 		dst_reg->umin_value <<= umin_val;
 		dst_reg->umax_value <<= umax_val;
 	}
+}
+
+static void scalar_min_max_lsh(struct bpf_reg_state *dst_reg,
+			       struct bpf_reg_state *src_reg)
+{
+	u64 umax_val = src_reg->umax_value;
+	u64 umin_val = src_reg->umin_value;
+
+	/* scalar64 calc uses 32bit unshifted bounds so must be called first */
+	__scalar64_min_max_lsh(dst_reg, umin_val, umax_val);
+	__scalar32_min_max_lsh(dst_reg, umin_val, umax_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);
 }
 
+static void scalar32_min_max_rsh(struct bpf_reg_state *dst_reg,
+				 struct bpf_reg_state *src_reg)
+{
+	struct tnum subreg = tnum_subreg(dst_reg->var_off);
+	u32 umax_val = src_reg->u32_max_value;
+	u32 umin_val = src_reg->u32_min_value;
+
+	/* BPF_RSH is an unsigned shift.  If the value in dst_reg might
+	 * be negative, then either:
+	 * 1) src_reg might be zero, so the sign bit of the result is
+	 *    unknown, so we lose our signed bounds
+	 * 2) it's known negative, thus the unsigned bounds capture the
+	 *    signed bounds
+	 * 3) the signed bounds cross zero, so they tell us nothing
+	 *    about the result
+	 * If the value in dst_reg is known nonnegative, then again the
+	 * unsigned bounts capture the signed bounds.
+	 * Thus, in all cases it suffices to blow away our signed bounds
+	 * and rely on inferring new ones from the unsigned bounds and
+	 * var_off of the result.
+	 */
+	dst_reg->s32_min_value = S32_MIN;
+	dst_reg->s32_max_value = S32_MAX;
+
+	dst_reg->var_off = tnum_rshift(subreg, umin_val);
+	dst_reg->u32_min_value >>= umax_val;
+	dst_reg->u32_max_value >>= umin_val;
+
+	__mark_reg64_unbounded(dst_reg);
+	__update_reg32_bounds(dst_reg);
+}
+
 static void scalar_min_max_rsh(struct bpf_reg_state *dst_reg,
 			       struct bpf_reg_state *src_reg)
 {
@@ -5039,35 +5529,62 @@ static void scalar_min_max_rsh(struct bpf_reg_state *dst_reg,
 	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 */
+
+	/* Its not easy to operate on alu32 bounds here because it depends
+	 * on bits being shifted in. Take easy way out and mark unbounded
+	 * so we can recalculate later from tnum.
+	 */
+	__mark_reg32_unbounded(dst_reg);
 	__update_reg_bounds(dst_reg);
 }
 
-static void scalar_min_max_arsh(struct bpf_reg_state *dst_reg,
-			        struct bpf_reg_state *src_reg,
-				u64 insn_bitness)
+static void scalar32_min_max_arsh(struct bpf_reg_state *dst_reg,
+				  struct bpf_reg_state *src_reg)
 {
-	u64 umin_val = src_reg->umin_value;
+	u64 umin_val = src_reg->u32_min_value;
 
 	/* Upon reaching here, src_known is true and
 	 * umax_val is equal to umin_val.
 	 */
-	if (insn_bitness == 32) {
-		dst_reg->smin_value = (u32)(((s32)dst_reg->smin_value) >> umin_val);
-		dst_reg->smax_value = (u32)(((s32)dst_reg->smax_value) >> umin_val);
-	} else {
-		dst_reg->smin_value >>= umin_val;
-		dst_reg->smax_value >>= umin_val;
-	}
+	dst_reg->s32_min_value = (u32)(((s32)dst_reg->s32_min_value) >> umin_val);
+	dst_reg->s32_max_value = (u32)(((s32)dst_reg->s32_max_value) >> umin_val);
 
-	dst_reg->var_off = tnum_arshift(dst_reg->var_off, umin_val,
-					insn_bitness);
+	dst_reg->var_off = tnum_arshift(tnum_subreg(dst_reg->var_off), umin_val, 32);
+
+	/* blow away the dst_reg umin_value/umax_value and rely on
+	 * dst_reg var_off to refine the result.
+	 */
+	dst_reg->u32_min_value = 0;
+	dst_reg->u32_max_value = U32_MAX;
+
+	__mark_reg64_unbounded(dst_reg);
+	__update_reg32_bounds(dst_reg);
+}
+
+static void scalar_min_max_arsh(struct bpf_reg_state *dst_reg,
+				struct bpf_reg_state *src_reg)
+{
+	u64 umin_val = src_reg->umin_value;
+
+	/* 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, 64);
 
 	/* 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;
+
+	/* Its not easy to operate on alu32 bounds here because it depends
+	 * on bits being shifted in from upper 32-bits. Take easy way out
+	 * and mark unbounded so we can recalculate later from tnum.
+	 */
+	__mark_reg32_unbounded(dst_reg);
 	__update_reg_bounds(dst_reg);
 }
 
@@ -5085,33 +5602,47 @@ static int adjust_scalar_min_max_vals(struct bpf_verifier_env *env,
 	bool src_known, dst_known;
 	s64 smin_val, smax_val;
 	u64 umin_val, umax_val;
+	s32 s32_min_val, s32_max_val;
+	u32 u32_min_val, u32_max_val;
 	u64 insn_bitness = (BPF_CLASS(insn->code) == BPF_ALU64) ? 64 : 32;
 	u32 dst = insn->dst_reg;
 	int ret;
-
-	if (insn_bitness == 32) {
-		/* Relevant for 32-bit RSH: Information can propagate towards
-		 * LSB, so it isn't sufficient to only truncate the output to
-		 * 32 bits.
-		 */
-		coerce_reg_to_size(dst_reg, 4);
-		coerce_reg_to_size(&src_reg, 4);
-	}
+	bool alu32 = (BPF_CLASS(insn->code) != BPF_ALU64);
 
 	smin_val = src_reg.smin_value;
 	smax_val = src_reg.smax_value;
 	umin_val = src_reg.umin_value;
 	umax_val = src_reg.umax_value;
-	src_known = tnum_is_const(src_reg.var_off);
-	dst_known = tnum_is_const(dst_reg->var_off);
 
-	if ((src_known && (smin_val != smax_val || umin_val != umax_val)) ||
-	    smin_val > smax_val || umin_val > umax_val) {
-		/* Taint dst register if offset had invalid bounds derived from
-		 * e.g. dead branches.
-		 */
-		__mark_reg_unknown(env, dst_reg);
-		return 0;
+	s32_min_val = src_reg.s32_min_value;
+	s32_max_val = src_reg.s32_max_value;
+	u32_min_val = src_reg.u32_min_value;
+	u32_max_val = src_reg.u32_max_value;
+
+	if (alu32) {
+		src_known = tnum_subreg_is_const(src_reg.var_off);
+		dst_known = tnum_subreg_is_const(dst_reg->var_off);
+		if ((src_known &&
+		     (s32_min_val != s32_max_val || u32_min_val != u32_max_val)) ||
+		    s32_min_val > s32_max_val || u32_min_val > u32_max_val) {
+			/* Taint dst register if offset had invalid bounds
+			 * derived from e.g. dead branches.
+			 */
+			__mark_reg_unknown(env, dst_reg);
+			return 0;
+		}
+	} else {
+		src_known = tnum_is_const(src_reg.var_off);
+		dst_known = tnum_is_const(dst_reg->var_off);
+		if ((src_known &&
+		     (smin_val != smax_val || umin_val != umax_val)) ||
+		    smin_val > smax_val || umin_val > umax_val) {
+			/* Taint dst register if offset had invalid bounds
+			 * derived from e.g. dead branches.
+			 */
+			__mark_reg_unknown(env, dst_reg);
+			return 0;
+		}
 	}
 
 	if (!src_known &&
@@ -5120,6 +5651,20 @@ static int adjust_scalar_min_max_vals(struct bpf_verifier_env *env,
 		return 0;
 	}
 
+	/* Calculate sign/unsigned bounds and tnum for alu32 and alu64 bit ops.
+	 * There are two classes of instructions: The first class we track both
+	 * alu32 and alu64 sign/unsigned bounds independently this provides the
+	 * greatest amount of precision when alu operations are mixed with jmp32
+	 * operations. These operations are BPF_ADD, BPF_SUB, BPF_MUL, BPF_ADD,
+	 * and BPF_OR. This is possible because these ops have fairly easy to
+	 * understand and calculate behavior in both 32-bit and 64-bit alu ops.
+	 * See alu32 verifier tests for examples. The second class of
+	 * operations, BPF_LSH, BPF_RSH, and BPF_ARSH, however are not so easy
+	 * with regards to tracking sign/unsigned bounds because the bits may
+	 * cross subreg boundaries in the alu64 case. When this happens we mark
+	 * the reg unbounded in the subreg bound space and use the resulting
+	 * tnum to calculate an approximation of the sign/unsigned bounds.
+	 */
 	switch (opcode) {
 	case BPF_ADD:
 		ret = sanitize_val_alu(env, insn);
@@ -5127,7 +5672,9 @@ static int adjust_scalar_min_max_vals(struct bpf_verifier_env *env,
 			verbose(env, "R%d tried to add from different pointers or scalars\n", dst);
 			return ret;
 		}
+		scalar32_min_max_add(dst_reg, &src_reg);
 		scalar_min_max_add(dst_reg, &src_reg);
+		dst_reg->var_off = tnum_add(dst_reg->var_off, src_reg.var_off);
 		break;
 	case BPF_SUB:
 		ret = sanitize_val_alu(env, insn);
@@ -5135,25 +5682,23 @@ static int adjust_scalar_min_max_vals(struct bpf_verifier_env *env,
 			verbose(env, "R%d tried to sub from different pointers or scalars\n", dst);
 			return ret;
 		}
+		scalar32_min_max_sub(dst_reg, &src_reg);
 		scalar_min_max_sub(dst_reg, &src_reg);
+		dst_reg->var_off = tnum_sub(dst_reg->var_off, src_reg.var_off);
 		break;
 	case BPF_MUL:
+		dst_reg->var_off = tnum_mul(dst_reg->var_off, src_reg.var_off);
+		scalar32_min_max_mul(dst_reg, &src_reg);
 		scalar_min_max_mul(dst_reg, &src_reg);
 		break;
 	case BPF_AND:
-		if (src_known && dst_known) {
-			__mark_reg_known(dst_reg, dst_reg->var_off.value &
-						  src_reg.var_off.value);
-			break;
-		}
+		dst_reg->var_off = tnum_and(dst_reg->var_off, src_reg.var_off);
+		scalar32_min_max_and(dst_reg, &src_reg);
 		scalar_min_max_and(dst_reg, &src_reg);
 		break;
 	case BPF_OR:
-		if (src_known && dst_known) {
-			__mark_reg_known(dst_reg, dst_reg->var_off.value |
-						  src_reg.var_off.value);
-			break;
-		}
+		dst_reg->var_off = tnum_or(dst_reg->var_off, src_reg.var_off);
+		scalar32_min_max_or(dst_reg, &src_reg);
 		scalar_min_max_or(dst_reg, &src_reg);
 		break;
 	case BPF_LSH:
@@ -5164,7 +5709,10 @@ static int adjust_scalar_min_max_vals(struct bpf_verifier_env *env,
 			mark_reg_unknown(env, regs, insn->dst_reg);
 			break;
 		}
-		scalar_min_max_lsh(dst_reg, &src_reg);
+		if (alu32)
+			scalar32_min_max_lsh(dst_reg, &src_reg);
+		else
+			scalar_min_max_lsh(dst_reg, &src_reg);
 		break;
 	case BPF_RSH:
 		if (umax_val >= insn_bitness) {
@@ -5174,7 +5722,10 @@ static int adjust_scalar_min_max_vals(struct bpf_verifier_env *env,
 			mark_reg_unknown(env, regs, insn->dst_reg);
 			break;
 		}
-		scalar_min_max_rsh(dst_reg, &src_reg);
+		if (alu32)
+			scalar32_min_max_rsh(dst_reg, &src_reg);
+		else
+			scalar_min_max_rsh(dst_reg, &src_reg);
 		break;
 	case BPF_ARSH:
 		if (umax_val >= insn_bitness) {
@@ -5184,17 +5735,19 @@ static int adjust_scalar_min_max_vals(struct bpf_verifier_env *env,
 			mark_reg_unknown(env, regs, insn->dst_reg);
 			break;
 		}
-		scalar_min_max_arsh(dst_reg, &src_reg, insn_bitness);
+		if (alu32)
+			scalar32_min_max_arsh(dst_reg, &src_reg);
+		else
+			scalar_min_max_arsh(dst_reg, &src_reg);
 		break;
 	default:
 		mark_reg_unknown(env, regs, insn->dst_reg);
 		break;
 	}
 
-	if (BPF_CLASS(insn->code) != BPF_ALU64) {
-		/* 32-bit ALU ops are (32,32)->32 */
-		coerce_reg_to_size(dst_reg, 4);
-	}
+	/* ALU32 ops are zero extended into 64bit register */
+	if (alu32)
+		zext_32_to_64(dst_reg);
 
 	__update_reg_bounds(dst_reg);
 	__reg_deduce_bounds(dst_reg);
@@ -5370,7 +5923,7 @@ static int check_alu_op(struct bpf_verifier_env *env, struct bpf_insn *insn)
 					mark_reg_unknown(env, regs,
 							 insn->dst_reg);
 				}
-				coerce_reg_to_size(dst_reg, 4);
+				zext_32_to_64(dst_reg);
 			}
 		} else {
 			/* case: R = imm
@@ -5540,55 +6093,83 @@ static void find_good_pkt_pointers(struct bpf_verifier_state *vstate,
 					 new_range);
 }
 
-/* compute branch direction of the expression "if (reg opcode val) goto target;"
- * and return:
- *  1 - branch will be taken and "goto target" will be executed
- *  0 - branch will not be taken and fall-through to next insn
- * -1 - unknown. Example: "if (reg < 5)" is unknown when register value range [0,10]
- */
-static int is_branch_taken(struct bpf_reg_state *reg, u64 val, u8 opcode,
-			   bool is_jmp32)
+static int is_branch32_taken(struct bpf_reg_state *reg, u32 val, u8 opcode)
 {
-	struct bpf_reg_state reg_lo;
-	s64 sval;
+	struct tnum subreg = tnum_subreg(reg->var_off);
+	s32 sval = (s32)val;
 
-	if (__is_pointer_value(false, reg))
-		return -1;
+	switch (opcode) {
+	case BPF_JEQ:
+		if (tnum_is_const(subreg))
+			return !!tnum_equals_const(subreg, val);
+		break;
+	case BPF_JNE:
+		if (tnum_is_const(subreg))
+			return !tnum_equals_const(subreg, val);
+		break;
+	case BPF_JSET:
+		if ((~subreg.mask & subreg.value) & val)
+			return 1;
+		if (!((subreg.mask | subreg.value) & val))
+			return 0;
+		break;
+	case BPF_JGT:
+		if (reg->u32_min_value > val)
+			return 1;
+		else if (reg->u32_max_value <= val)
+			return 0;
+		break;
+	case BPF_JSGT:
+		if (reg->s32_min_value > sval)
+			return 1;
+		else if (reg->s32_max_value < sval)
+			return 0;
+		break;
+	case BPF_JLT:
+		if (reg->u32_max_value < val)
+			return 1;
+		else if (reg->u32_min_value >= val)
+			return 0;
+		break;
+	case BPF_JSLT:
+		if (reg->s32_max_value < sval)
+			return 1;
+		else if (reg->s32_min_value >= sval)
+			return 0;
+		break;
+	case BPF_JGE:
+		if (reg->u32_min_value >= val)
+			return 1;
+		else if (reg->u32_max_value < val)
+			return 0;
+		break;
+	case BPF_JSGE:
+		if (reg->s32_min_value >= sval)
+			return 1;
+		else if (reg->s32_max_value < sval)
+			return 0;
+		break;
+	case BPF_JLE:
+		if (reg->u32_max_value <= val)
+			return 1;
+		else if (reg->u32_min_value > val)
+			return 0;
+		break;
+	case BPF_JSLE:
+		if (reg->s32_max_value <= sval)
+			return 1;
+		else if (reg->s32_min_value > sval)
+			return 0;
+		break;
+	}
 
-	if (is_jmp32) {
-		reg_lo = *reg;
-		reg = &reg_lo;
-		/* For JMP32, only low 32 bits are compared, coerce_reg_to_size
-		 * could truncate high bits and update umin/umax according to
-		 * information of low bits.
-		 */
-		coerce_reg_to_size(reg, 4);
-		/* smin/smax need special handling. For example, after coerce,
-		 * if smin_value is 0x00000000ffffffffLL, the value is -1 when
-		 * used as operand to JMP32. It is a negative number from s32's
-		 * point of view, while it is a positive number when seen as
-		 * s64. The smin/smax are kept as s64, therefore, when used with
-		 * JMP32, they need to be transformed into s32, then sign
-		 * extended back to s64.
-		 *
-		 * Also, smin/smax were copied from umin/umax. If umin/umax has
-		 * different sign bit, then min/max relationship doesn't
-		 * maintain after casting into s32, for this case, set smin/smax
-		 * to safest range.
-		 */
-		if ((reg->umax_value ^ reg->umin_value) &
-		    (1ULL << 31)) {
-			reg->smin_value = S32_MIN;
-			reg->smax_value = S32_MAX;
-		}
-		reg->smin_value = (s64)(s32)reg->smin_value;
-		reg->smax_value = (s64)(s32)reg->smax_value;
+	return -1;
+}
 
-		val = (u32)val;
-		sval = (s64)(s32)val;
-	} else {
-		sval = (s64)val;
-	}
+
+static int is_branch64_taken(struct bpf_reg_state *reg, u64 val, u8 opcode)
+{
+	s64 sval = (s64)val;
 
 	switch (opcode) {
 	case BPF_JEQ:
@@ -5658,91 +6239,22 @@ static int is_branch_taken(struct bpf_reg_state *reg, u64 val, u8 opcode,
 	return -1;
 }
 
-/* Generate min value of the high 32-bit from TNUM info. */
-static u64 gen_hi_min(struct tnum var)
-{
-	return var.value & ~0xffffffffULL;
-}
-
-/* Generate max value of the high 32-bit from TNUM info. */
-static u64 gen_hi_max(struct tnum var)
-{
-	return (var.value | var.mask) & ~0xffffffffULL;
-}
-
-/* Return true if VAL is compared with a s64 sign extended from s32, and they
- * are with the same signedness.
- */
-static bool cmp_val_with_extended_s64(s64 sval, struct bpf_reg_state *reg)
-{
-	return ((s32)sval >= 0 &&
-		reg->smin_value >= 0 && reg->smax_value <= S32_MAX) ||
-	       ((s32)sval < 0 &&
-		reg->smax_value <= 0 && reg->smin_value >= S32_MIN);
-}
-
-/* Constrain the possible values of @reg with unsigned upper bound @bound.
- * If @is_exclusive, @bound is an exclusive limit, otherwise it is inclusive.
- * If @is_jmp32, @bound is a 32-bit value that only constrains the low 32 bits
- * of @reg.
- */
-static void set_upper_bound(struct bpf_reg_state *reg, u64 bound, bool is_jmp32,
-			    bool is_exclusive)
-{
-	if (is_exclusive) {
-		/* There are no values for `reg` that make `reg<0` true. */
-		if (bound == 0)
-			return;
-		bound--;
-	}
-	if (is_jmp32) {
-		/* Constrain the register's value in the tnum representation.
-		 * For 64-bit comparisons this happens later in
-		 * __reg_bound_offset(), but for 32-bit comparisons, we can be
-		 * more precise than what can be derived from the updated
-		 * numeric bounds.
-		 */
-		struct tnum t = tnum_range(0, bound);
-
-		t.mask |= ~0xffffffffULL; /* upper half is unknown */
-		reg->var_off = tnum_intersect(reg->var_off, t);
-
-		/* Compute the 64-bit bound from the 32-bit bound. */
-		bound += gen_hi_max(reg->var_off);
-	}
-	reg->umax_value = min(reg->umax_value, bound);
-}
-
-/* Constrain the possible values of @reg with unsigned lower bound @bound.
- * If @is_exclusive, @bound is an exclusive limit, otherwise it is inclusive.
- * If @is_jmp32, @bound is a 32-bit value that only constrains the low 32 bits
- * of @reg.
+/* compute branch direction of the expression "if (reg opcode val) goto target;"
+ * and return:
+ *  1 - branch will be taken and "goto target" will be executed
+ *  0 - branch will not be taken and fall-through to next insn
+ * -1 - unknown. Example: "if (reg < 5)" is unknown when register value
+ *      range [0,10]
  */
-static void set_lower_bound(struct bpf_reg_state *reg, u64 bound, bool is_jmp32,
-			    bool is_exclusive)
+static int is_branch_taken(struct bpf_reg_state *reg, u64 val, u8 opcode,
+			   bool is_jmp32)
 {
-	if (is_exclusive) {
-		/* There are no values for `reg` that make `reg>MAX` true. */
-		if (bound == (is_jmp32 ? U32_MAX : U64_MAX))
-			return;
-		bound++;
-	}
-	if (is_jmp32) {
-		/* Constrain the register's value in the tnum representation.
-		 * For 64-bit comparisons this happens later in
-		 * __reg_bound_offset(), but for 32-bit comparisons, we can be
-		 * more precise than what can be derived from the updated
-		 * numeric bounds.
-		 */
-		struct tnum t = tnum_range(bound, U32_MAX);
-
-		t.mask |= ~0xffffffffULL; /* upper half is unknown */
-		reg->var_off = tnum_intersect(reg->var_off, t);
+	if (__is_pointer_value(false, reg))
+		return -1;
 
-		/* Compute the 64-bit bound from the 32-bit bound. */
-		bound += gen_hi_min(reg->var_off);
-	}
-	reg->umin_value = max(reg->umin_value, bound);
+	if (is_jmp32)
+		return is_branch32_taken(reg, val, opcode);
+	return is_branch64_taken(reg, val, opcode);
 }
 
 /* Adjusts the register min/max values in the case that the dst_reg is the
@@ -5751,10 +6263,16 @@ static void set_lower_bound(struct bpf_reg_state *reg, u64 bound, bool is_jmp32,
  * In JEQ/JNE cases we also adjust the var_off values.
  */
 static void reg_set_min_max(struct bpf_reg_state *true_reg,
-			    struct bpf_reg_state *false_reg, u64 val,
+			    struct bpf_reg_state *false_reg,
+			    u64 val, u32 val32,
 			    u8 opcode, bool is_jmp32)
 {
-	s64 sval;
+	struct tnum false_32off = tnum_subreg(false_reg->var_off);
+	struct tnum false_64off = false_reg->var_off;
+	struct tnum true_32off = tnum_subreg(true_reg->var_off);
+	struct tnum true_64off = true_reg->var_off;
+	s64 sval = (s64)val;
+	s32 sval32 = (s32)val32;
 
 	/* If the dst_reg is a pointer, we can't learn anything about its
 	 * variable offset from the compare (unless src_reg were a pointer into
@@ -5765,9 +6283,6 @@ static void reg_set_min_max(struct bpf_reg_state *true_reg,
 	if (__is_pointer_value(false, false_reg))
 		return;
 
-	val = is_jmp32 ? (u32)val : val;
-	sval = is_jmp32 ? (s64)(s32)val : (s64)val;
-
 	switch (opcode) {
 	case BPF_JEQ:
 	case BPF_JNE:
@@ -5779,87 +6294,126 @@ static void reg_set_min_max(struct bpf_reg_state *true_reg,
 		 * if it is true we know the value for sure. Likewise for
 		 * BPF_JNE.
 		 */
-		if (is_jmp32) {
-			u64 old_v = reg->var_off.value;
-			u64 hi_mask = ~0xffffffffULL;
-
-			reg->var_off.value = (old_v & hi_mask) | val;
-			reg->var_off.mask &= hi_mask;
-		} else {
+		if (is_jmp32)
+			__mark_reg32_known(reg, val32);
+		else
 			__mark_reg_known(reg, val);
-		}
 		break;
 	}
 	case BPF_JSET:
-		false_reg->var_off = tnum_and(false_reg->var_off,
-					      tnum_const(~val));
-		if (is_power_of_2(val))
-			true_reg->var_off = tnum_or(true_reg->var_off,
-						    tnum_const(val));
+		if (is_jmp32) {
+			false_32off = tnum_and(false_32off, tnum_const(~val32));
+			if (is_power_of_2(val32))
+				true_32off = tnum_or(true_32off,
+						     tnum_const(val32));
+		} else {
+			false_64off = tnum_and(false_64off, tnum_const(~val));
+			if (is_power_of_2(val))
+				true_64off = tnum_or(true_64off,
+						     tnum_const(val));
+		}
 		break;
 	case BPF_JGE:
 	case BPF_JGT:
 	{
-		set_upper_bound(false_reg, val, is_jmp32, opcode == BPF_JGE);
-		set_lower_bound(true_reg, val, is_jmp32, opcode == BPF_JGT);
+		if (is_jmp32) {
+			u32 false_umax = opcode == BPF_JGT ? val32  : val32 - 1;
+			u32 true_umin = opcode == BPF_JGT ? val32 + 1 : val32;
+
+			false_reg->u32_max_value = min(false_reg->u32_max_value,
+						       false_umax);
+			true_reg->u32_min_value = max(true_reg->u32_min_value,
+						      true_umin);
+		} else {
+			u64 false_umax = opcode == BPF_JGT ? val    : val - 1;
+			u64 true_umin = opcode == BPF_JGT ? val + 1 : val;
+
+			false_reg->umax_value = min(false_reg->umax_value, false_umax);
+			true_reg->umin_value = max(true_reg->umin_value, true_umin);
+		}
 		break;
 	}
 	case BPF_JSGE:
 	case BPF_JSGT:
 	{
-		s64 false_smax = opcode == BPF_JSGT ? sval    : sval - 1;
-		s64 true_smin = opcode == BPF_JSGT ? sval + 1 : sval;
+		if (is_jmp32) {
+			s32 false_smax = opcode == BPF_JSGT ? sval32    : sval32 - 1;
+			s32 true_smin = opcode == BPF_JSGT ? sval32 + 1 : sval32;
 
-		/* If the full s64 was not sign-extended from s32 then don't
-		 * deduct further info.
-		 */
-		if (is_jmp32 && !cmp_val_with_extended_s64(sval, false_reg))
-			break;
-		false_reg->smax_value = min(false_reg->smax_value, false_smax);
-		true_reg->smin_value = max(true_reg->smin_value, true_smin);
+			false_reg->s32_max_value = min(false_reg->s32_max_value, false_smax);
+			true_reg->s32_min_value = max(true_reg->s32_min_value, true_smin);
+		} else {
+			s64 false_smax = opcode == BPF_JSGT ? sval    : sval - 1;
+			s64 true_smin = opcode == BPF_JSGT ? sval + 1 : sval;
+
+			false_reg->smax_value = min(false_reg->smax_value, false_smax);
+			true_reg->smin_value = max(true_reg->smin_value, true_smin);
+		}
 		break;
 	}
 	case BPF_JLE:
 	case BPF_JLT:
 	{
-		set_lower_bound(false_reg, val, is_jmp32, opcode == BPF_JLE);
-		set_upper_bound(true_reg, val, is_jmp32, opcode == BPF_JLT);
+		if (is_jmp32) {
+			u32 false_umin = opcode == BPF_JLT ? val32  : val32 + 1;
+			u32 true_umax = opcode == BPF_JLT ? val32 - 1 : val32;
+
+			false_reg->u32_min_value = max(false_reg->u32_min_value,
+						       false_umin);
+			true_reg->u32_max_value = min(true_reg->u32_max_value,
+						      true_umax);
+		} else {
+			u64 false_umin = opcode == BPF_JLT ? val    : val + 1;
+			u64 true_umax = opcode == BPF_JLT ? val - 1 : val;
+
+			false_reg->umin_value = max(false_reg->umin_value, false_umin);
+			true_reg->umax_value = min(true_reg->umax_value, true_umax);
+		}
 		break;
 	}
 	case BPF_JSLE:
 	case BPF_JSLT:
 	{
-		s64 false_smin = opcode == BPF_JSLT ? sval    : sval + 1;
-		s64 true_smax = opcode == BPF_JSLT ? sval - 1 : sval;
+		if (is_jmp32) {
+			s32 false_smin = opcode == BPF_JSLT ? sval32    : sval32 + 1;
+			s32 true_smax = opcode == BPF_JSLT ? sval32 - 1 : sval32;
 
-		if (is_jmp32 && !cmp_val_with_extended_s64(sval, false_reg))
-			break;
-		false_reg->smin_value = max(false_reg->smin_value, false_smin);
-		true_reg->smax_value = min(true_reg->smax_value, true_smax);
+			false_reg->s32_min_value = max(false_reg->s32_min_value, false_smin);
+			true_reg->s32_max_value = min(true_reg->s32_max_value, true_smax);
+		} else {
+			s64 false_smin = opcode == BPF_JSLT ? sval    : sval + 1;
+			s64 true_smax = opcode == BPF_JSLT ? sval - 1 : sval;
+
+			false_reg->smin_value = max(false_reg->smin_value, false_smin);
+			true_reg->smax_value = min(true_reg->smax_value, true_smax);
+		}
 		break;
 	}
 	default:
 		return;
 	}
 
-	__reg_deduce_bounds(false_reg);
-	__reg_deduce_bounds(true_reg);
-	/* We might have learned some bits from the bounds. */
-	__reg_bound_offset(false_reg);
-	__reg_bound_offset(true_reg);
-	/* Intersecting with the old var_off might have improved our bounds
-	 * slightly.  e.g. if umax was 0x7f...f and var_off was (0; 0xf...fc),
-	 * then new var_off is (0; 0x7f...fc) which improves our umax.
-	 */
-	__update_reg_bounds(false_reg);
-	__update_reg_bounds(true_reg);
+	if (is_jmp32) {
+		false_reg->var_off = tnum_or(tnum_clear_subreg(false_64off),
+					     tnum_subreg(false_32off));
+		true_reg->var_off = tnum_or(tnum_clear_subreg(true_64off),
+					    tnum_subreg(true_32off));
+		__reg_combine_32_into_64(false_reg);
+		__reg_combine_32_into_64(true_reg);
+	} else {
+		false_reg->var_off = false_64off;
+		true_reg->var_off = true_64off;
+		__reg_combine_64_into_32(false_reg);
+		__reg_combine_64_into_32(true_reg);
+	}
 }
 
 /* Same as above, but for the case that dst_reg holds a constant and src_reg is
  * the variable reg.
  */
 static void reg_set_min_max_inv(struct bpf_reg_state *true_reg,
-				struct bpf_reg_state *false_reg, u64 val,
+				struct bpf_reg_state *false_reg,
+				u64 val, u32 val32,
 				u8 opcode, bool is_jmp32)
 {
 	/* How can we transform "a <op> b" into "b <op> a"? */
@@ -5883,7 +6437,7 @@ static void reg_set_min_max_inv(struct bpf_reg_state *true_reg,
 	 * BPF_JA, can't get here.
 	 */
 	if (opcode)
-		reg_set_min_max(true_reg, false_reg, val, opcode, is_jmp32);
+		reg_set_min_max(true_reg, false_reg, val, val32, opcode, is_jmp32);
 }
 
 /* Regs are known to be equal, so intersect their min/max/var_off */
@@ -6172,13 +6726,22 @@ static int check_cond_jmp_op(struct bpf_verifier_env *env,
 	dst_reg = &regs[insn->dst_reg];
 	is_jmp32 = BPF_CLASS(insn->code) == BPF_JMP32;
 
-	if (BPF_SRC(insn->code) == BPF_K)
-		pred = is_branch_taken(dst_reg, insn->imm,
-				       opcode, is_jmp32);
-	else if (src_reg->type == SCALAR_VALUE &&
-		 tnum_is_const(src_reg->var_off))
-		pred = is_branch_taken(dst_reg, src_reg->var_off.value,
-				       opcode, is_jmp32);
+	if (BPF_SRC(insn->code) == BPF_K) {
+		pred = is_branch_taken(dst_reg, insn->imm, opcode, is_jmp32);
+	} else if (src_reg->type == SCALAR_VALUE &&
+		   is_jmp32 && tnum_is_const(tnum_subreg(src_reg->var_off))) {
+		pred = is_branch_taken(dst_reg,
+				       tnum_subreg(src_reg->var_off).value,
+				       opcode,
+				       is_jmp32);
+	} else if (src_reg->type == SCALAR_VALUE &&
+		   !is_jmp32 && tnum_is_const(src_reg->var_off)) {
+		pred = is_branch_taken(dst_reg,
+				       src_reg->var_off.value,
+				       opcode,
+				       is_jmp32);
+	}
+
 	if (pred >= 0) {
 		err = mark_chain_precision(env, insn->dst_reg);
 		if (BPF_SRC(insn->code) == BPF_X && !err)
@@ -6212,32 +6775,24 @@ static int check_cond_jmp_op(struct bpf_verifier_env *env,
 	 */
 	if (BPF_SRC(insn->code) == BPF_X) {
 		struct bpf_reg_state *src_reg = &regs[insn->src_reg];
-		struct bpf_reg_state lo_reg0 = *dst_reg;
-		struct bpf_reg_state lo_reg1 = *src_reg;
-		struct bpf_reg_state *src_lo, *dst_lo;
-
-		dst_lo = &lo_reg0;
-		src_lo = &lo_reg1;
-		coerce_reg_to_size(dst_lo, 4);
-		coerce_reg_to_size(src_lo, 4);
 
 		if (dst_reg->type == SCALAR_VALUE &&
 		    src_reg->type == SCALAR_VALUE) {
 			if (tnum_is_const(src_reg->var_off) ||
-			    (is_jmp32 && tnum_is_const(src_lo->var_off)))
+			    (is_jmp32 &&
+			     tnum_is_const(tnum_subreg(src_reg->var_off))))
 				reg_set_min_max(&other_branch_regs[insn->dst_reg],
 						dst_reg,
-						is_jmp32
-						? src_lo->var_off.value
-						: src_reg->var_off.value,
+						src_reg->var_off.value,
+						tnum_subreg(src_reg->var_off).value,
 						opcode, is_jmp32);
 			else if (tnum_is_const(dst_reg->var_off) ||
-				 (is_jmp32 && tnum_is_const(dst_lo->var_off)))
+				 (is_jmp32 &&
+				  tnum_is_const(tnum_subreg(dst_reg->var_off))))
 				reg_set_min_max_inv(&other_branch_regs[insn->src_reg],
 						    src_reg,
-						    is_jmp32
-						    ? dst_lo->var_off.value
-						    : dst_reg->var_off.value,
+						    dst_reg->var_off.value,
+						    tnum_subreg(dst_reg->var_off).value,
 						    opcode, is_jmp32);
 			else if (!is_jmp32 &&
 				 (opcode == BPF_JEQ || opcode == BPF_JNE))
@@ -6248,7 +6803,8 @@ static int check_cond_jmp_op(struct bpf_verifier_env *env,
 		}
 	} else if (dst_reg->type == SCALAR_VALUE) {
 		reg_set_min_max(&other_branch_regs[insn->dst_reg],
-					dst_reg, insn->imm, opcode, is_jmp32);
+					dst_reg, insn->imm, (u32)insn->imm,
+					opcode, is_jmp32);
 	}
 
 	/* detect if R == 0 where R is returned from bpf_map_lookup_elem().
