diff --git a/include/linux/bpf_verifier.h b/include/linux/bpf_verifier.h
index 3378cc753061e6..bada59812e0034 100644
--- a/include/linux/bpf_verifier.h
+++ b/include/linux/bpf_verifier.h
@@ -325,12 +325,34 @@ struct bpf_func_state {
 	int allocated_stack;
 };
 
-struct bpf_idx_pair {
-	u32 prev_idx;
+#define MAX_CALL_FRAMES 8
+
+/* instruction history flags, used in bpf_jmp_history_entry.flags field */
+enum {
+	/* instruction references stack slot through PTR_TO_STACK register;
+	 * we also store stack's frame number in lower 3 bits (MAX_CALL_FRAMES is 8)
+	 * and accessed stack slot's index in next 6 bits (MAX_BPF_STACK is 512,
+	 * 8 bytes per slot, so slot index (spi) is [0, 63])
+	 */
+	INSN_F_FRAMENO_MASK = 0x7, /* 3 bits */
+
+	INSN_F_SPI_MASK = 0x3f, /* 6 bits */
+	INSN_F_SPI_SHIFT = 3, /* shifted 3 bits to the left */
+
+	INSN_F_STACK_ACCESS = BIT(9), /* we need 10 bits total */
+};
+
+static_assert(INSN_F_FRAMENO_MASK + 1 >= MAX_CALL_FRAMES);
+static_assert(INSN_F_SPI_MASK + 1 >= MAX_BPF_STACK / 8);
+
+struct bpf_jmp_history_entry {
 	u32 idx;
+	/* insn idx can't be bigger than 1 million */
+	u32 prev_idx : 22;
+	/* special flags, e.g., whether insn is doing register stack spill/load */
+	u32 flags : 10;
 };
 
-#define MAX_CALL_FRAMES 8
 /* Maximum number of register states that can exist at once */
 #define BPF_ID_MAP_SIZE ((MAX_BPF_REG + MAX_BPF_STACK / BPF_REG_SIZE) * MAX_CALL_FRAMES)
 struct bpf_verifier_state {
@@ -413,7 +435,7 @@ struct bpf_verifier_state {
 	 * For most states jmp_history_cnt is [0-3].
 	 * For loops can go up to ~40.
 	 */
-	struct bpf_idx_pair *jmp_history;
+	struct bpf_jmp_history_entry *jmp_history;
 	u32 jmp_history_cnt;
 	u32 dfs_depth;
 	u32 callback_unroll_depth;
@@ -656,6 +678,7 @@ struct bpf_verifier_env {
 		int cur_stack;
 	} cfg;
 	struct backtrack_state bt;
+	struct bpf_jmp_history_entry *cur_hist_ent;
 	u32 pass_cnt; /* number of times do_check() was called */
 	u32 subprog_cnt;
 	/* number of instructions analyzed by the verifier */
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 1ed39665f80219..e5ce530641ba0c 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -1144,6 +1144,21 @@ static bool is_spilled_scalar_reg(const struct bpf_stack_state *stack)
 	       stack->spilled_ptr.type == SCALAR_VALUE;
 }
 
+/* Mark stack slot as STACK_MISC, unless it is already STACK_INVALID, in which
+ * case they are equivalent, or it's STACK_ZERO, in which case we preserve
+ * more precise STACK_ZERO.
+ * Note, in uprivileged mode leaving STACK_INVALID is wrong, so we take
+ * env->allow_ptr_leaks into account and force STACK_MISC, if necessary.
+ */
+static void mark_stack_slot_misc(struct bpf_verifier_env *env, u8 *stype)
+{
+	if (*stype == STACK_ZERO)
+		return;
+	if (env->allow_ptr_leaks && *stype == STACK_INVALID)
+		return;
+	*stype = STACK_MISC;
+}
+
 static void scrub_spilled_slot(u8 *stype)
 {
 	if (*stype != STACK_INVALID)
@@ -1355,8 +1370,8 @@ static int copy_verifier_state(struct bpf_verifier_state *dst_state,
 	int i, err;
 
 	dst_state->jmp_history = copy_array(dst_state->jmp_history, src->jmp_history,
-					    src->jmp_history_cnt, sizeof(struct bpf_idx_pair),
-					    GFP_USER);
+					  src->jmp_history_cnt, sizeof(*dst_state->jmp_history),
+					  GFP_USER);
 	if (!dst_state->jmp_history)
 		return -ENOMEM;
 	dst_state->jmp_history_cnt = src->jmp_history_cnt;
@@ -3221,6 +3236,21 @@ static int check_reg_arg(struct bpf_verifier_env *env, u32 regno,
 	return __check_reg_arg(env, state->regs, regno, t);
 }
 
+static int insn_stack_access_flags(int frameno, int spi)
+{
+	return INSN_F_STACK_ACCESS | (spi << INSN_F_SPI_SHIFT) | frameno;
+}
+
+static int insn_stack_access_spi(int insn_flags)
+{
+	return (insn_flags >> INSN_F_SPI_SHIFT) & INSN_F_SPI_MASK;
+}
+
+static int insn_stack_access_frameno(int insn_flags)
+{
+	return insn_flags & INSN_F_FRAMENO_MASK;
+}
+
 static void mark_jmp_point(struct bpf_verifier_env *env, int idx)
 {
 	env->insn_aux_data[idx].jmp_point = true;
@@ -3232,28 +3262,51 @@ static bool is_jmp_point(struct bpf_verifier_env *env, int insn_idx)
 }
 
 /* for any branch, call, exit record the history of jmps in the given state */
-static int push_jmp_history(struct bpf_verifier_env *env,
-			    struct bpf_verifier_state *cur)
+static int push_jmp_history(struct bpf_verifier_env *env, struct bpf_verifier_state *cur,
+			    int insn_flags)
 {
 	u32 cnt = cur->jmp_history_cnt;
-	struct bpf_idx_pair *p;
+	struct bpf_jmp_history_entry *p;
 	size_t alloc_size;
 
-	if (!is_jmp_point(env, env->insn_idx))
+	/* combine instruction flags if we already recorded this instruction */
+	if (env->cur_hist_ent) {
+		/* atomic instructions push insn_flags twice, for READ and
+		 * WRITE sides, but they should agree on stack slot
+		 */
+		WARN_ONCE((env->cur_hist_ent->flags & insn_flags) &&
+			  (env->cur_hist_ent->flags & insn_flags) != insn_flags,
+			  "verifier insn history bug: insn_idx %d cur flags %x new flags %x\n",
+			  env->insn_idx, env->cur_hist_ent->flags, insn_flags);
+		env->cur_hist_ent->flags |= insn_flags;
 		return 0;
+	}
 
 	cnt++;
 	alloc_size = kmalloc_size_roundup(size_mul(cnt, sizeof(*p)));
 	p = krealloc(cur->jmp_history, alloc_size, GFP_USER);
 	if (!p)
 		return -ENOMEM;
-	p[cnt - 1].idx = env->insn_idx;
-	p[cnt - 1].prev_idx = env->prev_insn_idx;
 	cur->jmp_history = p;
+
+	p = &cur->jmp_history[cnt - 1];
+	p->idx = env->insn_idx;
+	p->prev_idx = env->prev_insn_idx;
+	p->flags = insn_flags;
 	cur->jmp_history_cnt = cnt;
+	env->cur_hist_ent = p;
+
 	return 0;
 }
 
+static struct bpf_jmp_history_entry *get_jmp_hist_entry(struct bpf_verifier_state *st,
+						        u32 hist_end, int insn_idx)
+{
+	if (hist_end > 0 && st->jmp_history[hist_end - 1].idx == insn_idx)
+		return &st->jmp_history[hist_end - 1];
+	return NULL;
+}
+
 /* Backtrack one insn at a time. If idx is not at the top of recorded
  * history then previous instruction came from straight line execution.
  * Return -ENOENT if we exhausted all instructions within given state.
@@ -3415,9 +3468,14 @@ static inline bool bt_is_reg_set(struct backtrack_state *bt, u32 reg)
 	return bt->reg_masks[bt->frame] & (1 << reg);
 }
 
+static inline bool bt_is_frame_slot_set(struct backtrack_state *bt, u32 frame, u32 slot)
+{
+	return bt->stack_masks[frame] & (1ull << slot);
+}
+
 static inline bool bt_is_slot_set(struct backtrack_state *bt, u32 slot)
 {
-	return bt->stack_masks[bt->frame] & (1ull << slot);
+	return bt_is_frame_slot_set(bt, bt->frame, slot);
 }
 
 /* format registers bitmask, e.g., "r0,r2,r4" for 0x15 mask */
@@ -3471,7 +3529,7 @@ static bool calls_callback(struct bpf_verifier_env *env, int insn_idx);
  *   - *was* processed previously during backtracking.
  */
 static int backtrack_insn(struct bpf_verifier_env *env, int idx, int subseq_idx,
-			  struct backtrack_state *bt)
+			  struct bpf_jmp_history_entry *hist, struct backtrack_state *bt)
 {
 	const struct bpf_insn_cbs cbs = {
 		.cb_call	= disasm_kfunc_name,
@@ -3484,7 +3542,7 @@ static int backtrack_insn(struct bpf_verifier_env *env, int idx, int subseq_idx,
 	u8 mode = BPF_MODE(insn->code);
 	u32 dreg = insn->dst_reg;
 	u32 sreg = insn->src_reg;
-	u32 spi, i;
+	u32 spi, i, fr;
 
 	if (insn->code == 0)
 		return 0;
@@ -3545,20 +3603,15 @@ static int backtrack_insn(struct bpf_verifier_env *env, int idx, int subseq_idx,
 		 * by 'precise' mark in corresponding register of this state.
 		 * No further tracking necessary.
 		 */
-		if (insn->src_reg != BPF_REG_FP)
+		if (!hist || !(hist->flags & INSN_F_STACK_ACCESS))
 			return 0;
-
 		/* dreg = *(u64 *)[fp - off] was a fill from the stack.
 		 * that [fp - off] slot contains scalar that needs to be
 		 * tracked with precision
 		 */
-		spi = (-insn->off - 1) / BPF_REG_SIZE;
-		if (spi >= 64) {
-			verbose(env, "BUG spi %d\n", spi);
-			WARN_ONCE(1, "verifier backtracking bug");
-			return -EFAULT;
-		}
-		bt_set_slot(bt, spi);
+		spi = insn_stack_access_spi(hist->flags);
+		fr = insn_stack_access_frameno(hist->flags);
+		bt_set_frame_slot(bt, fr, spi);
 	} else if (class == BPF_STX || class == BPF_ST) {
 		if (bt_is_reg_set(bt, dreg))
 			/* stx & st shouldn't be using _scalar_ dst_reg
@@ -3567,17 +3620,13 @@ static int backtrack_insn(struct bpf_verifier_env *env, int idx, int subseq_idx,
 			 */
 			return -ENOTSUPP;
 		/* scalars can only be spilled into stack */
-		if (insn->dst_reg != BPF_REG_FP)
+		if (!hist || !(hist->flags & INSN_F_STACK_ACCESS))
 			return 0;
-		spi = (-insn->off - 1) / BPF_REG_SIZE;
-		if (spi >= 64) {
-			verbose(env, "BUG spi %d\n", spi);
-			WARN_ONCE(1, "verifier backtracking bug");
-			return -EFAULT;
-		}
-		if (!bt_is_slot_set(bt, spi))
+		spi = insn_stack_access_spi(hist->flags);
+		fr = insn_stack_access_frameno(hist->flags);
+		if (!bt_is_frame_slot_set(bt, fr, spi))
 			return 0;
-		bt_clear_slot(bt, spi);
+		bt_clear_frame_slot(bt, fr, spi);
 		if (class == BPF_STX)
 			bt_set_reg(bt, sreg);
 	} else if (class == BPF_JMP || class == BPF_JMP32) {
@@ -3621,10 +3670,14 @@ static int backtrack_insn(struct bpf_verifier_env *env, int idx, int subseq_idx,
 					WARN_ONCE(1, "verifier backtracking bug");
 					return -EFAULT;
 				}
-				/* we don't track register spills perfectly,
-				 * so fallback to force-precise instead of failing */
-				if (bt_stack_mask(bt) != 0)
-					return -ENOTSUPP;
+				/* we are now tracking register spills correctly,
+				 * so any instance of leftover slots is a bug
+				 */
+				if (bt_stack_mask(bt) != 0) {
+					verbose(env, "BUG stack slots %llx\n", bt_stack_mask(bt));
+					WARN_ONCE(1, "verifier backtracking bug (subprog leftover stack slots)");
+					return -EFAULT;
+				}
 				/* propagate r1-r5 to the caller */
 				for (i = BPF_REG_1; i <= BPF_REG_5; i++) {
 					if (bt_is_reg_set(bt, i)) {
@@ -3649,8 +3702,11 @@ static int backtrack_insn(struct bpf_verifier_env *env, int idx, int subseq_idx,
 				WARN_ONCE(1, "verifier backtracking bug");
 				return -EFAULT;
 			}
-			if (bt_stack_mask(bt) != 0)
-				return -ENOTSUPP;
+			if (bt_stack_mask(bt) != 0) {
+				verbose(env, "BUG stack slots %llx\n", bt_stack_mask(bt));
+				WARN_ONCE(1, "verifier backtracking bug (callback leftover stack slots)");
+				return -EFAULT;
+			}
 			/* clear r1-r5 in callback subprog's mask */
 			for (i = BPF_REG_1; i <= BPF_REG_5; i++)
 				bt_clear_reg(bt, i);
@@ -4087,6 +4143,7 @@ static int __mark_chain_precision(struct bpf_verifier_env *env, int regno)
 	for (;;) {
 		DECLARE_BITMAP(mask, 64);
 		u32 history = st->jmp_history_cnt;
+		struct bpf_jmp_history_entry *hist;
 
 		if (env->log.level & BPF_LOG_LEVEL2) {
 			verbose(env, "mark_precise: frame%d: last_idx %d first_idx %d subseq_idx %d \n",
@@ -4150,7 +4207,8 @@ static int __mark_chain_precision(struct bpf_verifier_env *env, int regno)
 				err = 0;
 				skip_first = false;
 			} else {
-				err = backtrack_insn(env, i, subseq_idx, bt);
+				hist = get_jmp_hist_entry(st, history, i);
+				err = backtrack_insn(env, i, subseq_idx, hist, bt);
 			}
 			if (err == -ENOTSUPP) {
 				mark_all_scalars_precise(env, env->cur_state);
@@ -4203,22 +4261,10 @@ static int __mark_chain_precision(struct bpf_verifier_env *env, int regno)
 			bitmap_from_u64(mask, bt_frame_stack_mask(bt, fr));
 			for_each_set_bit(i, mask, 64) {
 				if (i >= func->allocated_stack / BPF_REG_SIZE) {
-					/* the sequence of instructions:
-					 * 2: (bf) r3 = r10
-					 * 3: (7b) *(u64 *)(r3 -8) = r0
-					 * 4: (79) r4 = *(u64 *)(r10 -8)
-					 * doesn't contain jmps. It's backtracked
-					 * as a single block.
-					 * During backtracking insn 3 is not recognized as
-					 * stack access, so at the end of backtracking
-					 * stack slot fp-8 is still marked in stack_mask.
-					 * However the parent state may not have accessed
-					 * fp-8 and it's "unallocated" stack space.
-					 * In such case fallback to conservative.
-					 */
-					mark_all_scalars_precise(env, env->cur_state);
-					bt_reset(bt);
-					return 0;
+					verbose(env, "BUG backtracking (stack slot %d, total slots %d)\n",
+						i, func->allocated_stack / BPF_REG_SIZE);
+					WARN_ONCE(1, "verifier backtracking bug (stack slot out of bounds)");
+					return -EFAULT;
 				}
 
 				if (!is_spilled_scalar_reg(&func->stack[i])) {
@@ -4355,7 +4401,8 @@ static void copy_register_state(struct bpf_reg_state *dst, const struct bpf_reg_
 	dst->live = live;
 }
 
-static void save_register_state(struct bpf_func_state *state,
+static void save_register_state(struct bpf_verifier_env *env,
+				struct bpf_func_state *state,
 				int spi, struct bpf_reg_state *reg,
 				int size)
 {
@@ -4370,7 +4417,7 @@ static void save_register_state(struct bpf_func_state *state,
 
 	/* size < 8 bytes spill */
 	for (; i; i--)
-		scrub_spilled_slot(&state->stack[spi].slot_type[i - 1]);
+		mark_stack_slot_misc(env, &state->stack[spi].slot_type[i - 1]);
 }
 
 static bool is_bpf_st_mem(struct bpf_insn *insn)
@@ -4391,7 +4438,7 @@ static int check_stack_write_fixed_off(struct bpf_verifier_env *env,
 	int i, slot = -off - 1, spi = slot / BPF_REG_SIZE, err;
 	struct bpf_insn *insn = &env->prog->insnsi[insn_idx];
 	struct bpf_reg_state *reg = NULL;
-	u32 dst_reg = insn->dst_reg;
+	int insn_flags = insn_stack_access_flags(state->frameno, spi);
 
 	err = grow_stack_state(state, round_up(slot + 1, BPF_REG_SIZE));
 	if (err)
@@ -4400,7 +4447,7 @@ static int check_stack_write_fixed_off(struct bpf_verifier_env *env,
 	 * so it's aligned access and [off, off + size) are within stack limits
 	 */
 	if (!env->allow_ptr_leaks &&
-	    state->stack[spi].slot_type[0] == STACK_SPILL &&
+	    is_spilled_reg(&state->stack[spi]) &&
 	    size != BPF_REG_SIZE) {
 		verbose(env, "attempt to corrupt spilled pointer on stack\n");
 		return -EACCES;
@@ -4430,20 +4477,8 @@ static int check_stack_write_fixed_off(struct bpf_verifier_env *env,
 		return err;
 
 	mark_stack_slot_scratched(env, spi);
-	if (reg && !(off % BPF_REG_SIZE) && register_is_bounded(reg) &&
-	    !register_is_null(reg) && env->bpf_capable) {
-		if (dst_reg != BPF_REG_FP) {
-			/* The backtracking logic can only recognize explicit
-			 * stack slot address like [fp - 8]. Other spill of
-			 * scalar via different register has to be conservative.
-			 * Backtrack from here and mark all registers as precise
-			 * that contributed into 'reg' being a constant.
-			 */
-			err = mark_chain_precision(env, value_regno);
-			if (err)
-				return err;
-		}
-		save_register_state(state, spi, reg, size);
+	if (reg && !(off % BPF_REG_SIZE) && register_is_bounded(reg) && env->bpf_capable) {
+		save_register_state(env, state, spi, reg, size);
 		/* Break the relation on a narrowing spill. */
 		if (fls64(reg->umax_value) > BITS_PER_BYTE * size)
 			state->stack[spi].spilled_ptr.id = 0;
@@ -4453,7 +4488,8 @@ static int check_stack_write_fixed_off(struct bpf_verifier_env *env,
 
 		__mark_reg_known(&fake_reg, insn->imm);
 		fake_reg.type = SCALAR_VALUE;
-		save_register_state(state, spi, &fake_reg, size);
+		save_register_state(env, state, spi, &fake_reg, size);
+		insn_flags = 0; /* not a register spill */
 	} else if (reg && is_spillable_regtype(reg->type)) {
 		/* register containing pointer is being spilled into stack */
 		if (size != BPF_REG_SIZE) {
@@ -4465,7 +4501,7 @@ static int check_stack_write_fixed_off(struct bpf_verifier_env *env,
 			verbose(env, "cannot spill pointers to stack into stack frame of the caller\n");
 			return -EINVAL;
 		}
-		save_register_state(state, spi, reg, size);
+		save_register_state(env, state, spi, reg, size);
 	} else {
 		u8 type = STACK_MISC;
 
@@ -4490,7 +4526,12 @@ static int check_stack_write_fixed_off(struct bpf_verifier_env *env,
 		/* when we zero initialize stack slots mark them as such */
 		if ((reg && register_is_null(reg)) ||
 		    (!reg && is_bpf_st_mem(insn) && insn->imm == 0)) {
-			/* backtracking doesn't work for STACK_ZERO yet. */
+			/* STACK_ZERO case happened because register spill
+			 * wasn't properly aligned at the stack slot boundary,
+			 * so it's not a register spill anymore; force
+			 * originating register to be precise to make
+			 * STACK_ZERO correct for subsequent states
+			 */
 			err = mark_chain_precision(env, value_regno);
 			if (err)
 				return err;
@@ -4499,9 +4540,12 @@ static int check_stack_write_fixed_off(struct bpf_verifier_env *env,
 
 		/* Mark slots affected by this stack write. */
 		for (i = 0; i < size; i++)
-			state->stack[spi].slot_type[(slot - i) % BPF_REG_SIZE] =
-				type;
+			state->stack[spi].slot_type[(slot - i) % BPF_REG_SIZE] = type;
+		insn_flags = 0; /* not a register spill */
 	}
+
+	if (insn_flags)
+		return push_jmp_history(env, env->cur_state, insn_flags);
 	return 0;
 }
 
@@ -4694,6 +4738,7 @@ static int check_stack_read_fixed_off(struct bpf_verifier_env *env,
 	int i, slot = -off - 1, spi = slot / BPF_REG_SIZE;
 	struct bpf_reg_state *reg;
 	u8 *stype, type;
+	int insn_flags = insn_stack_access_flags(reg_state->frameno, spi);
 
 	stype = reg_state->stack[spi].slot_type;
 	reg = &reg_state->stack[spi].spilled_ptr;
@@ -4726,25 +4771,42 @@ static int check_stack_read_fixed_off(struct bpf_verifier_env *env,
 				copy_register_state(&state->regs[dst_regno], reg);
 				state->regs[dst_regno].subreg_def = subreg_def;
 			} else {
+				int spill_cnt = 0, zero_cnt = 0;
+
 				for (i = 0; i < size; i++) {
 					type = stype[(slot - i) % BPF_REG_SIZE];
-					if (type == STACK_SPILL)
+					if (type == STACK_SPILL) {
+						spill_cnt++;
 						continue;
+					}
 					if (type == STACK_MISC)
 						continue;
+					if (type == STACK_ZERO) {
+						zero_cnt++;
+						continue;
+					}
 					if (type == STACK_INVALID && env->allow_uninit_stack)
 						continue;
 					verbose(env, "invalid read from stack off %d+%d size %d\n",
 						off, i, size);
 					return -EACCES;
 				}
-				mark_reg_unknown(env, state->regs, dst_regno);
+
+				if (spill_cnt == size &&
+				    tnum_is_const(reg->var_off) && reg->var_off.value == 0) {
+					__mark_reg_const_zero(&state->regs[dst_regno]);
+					/* this IS register fill, so keep insn_flags */
+				} else if (zero_cnt == size) {
+					/* similarly to mark_reg_stack_read(), preserve zeroes */
+					__mark_reg_const_zero(&state->regs[dst_regno]);
+					insn_flags = 0; /* not restoring original register state */
+				} else {
+					mark_reg_unknown(env, state->regs, dst_regno);
+					insn_flags = 0; /* not restoring original register state */
+				}
 			}
 			state->regs[dst_regno].live |= REG_LIVE_WRITTEN;
-			return 0;
-		}
-
-		if (dst_regno >= 0) {
+		} else if (dst_regno >= 0) {
 			/* restore register state from stack */
 			copy_register_state(&state->regs[dst_regno], reg);
 			/* mark reg as written since spilled pointer state likely
@@ -4780,7 +4842,10 @@ static int check_stack_read_fixed_off(struct bpf_verifier_env *env,
 		mark_reg_read(env, reg, reg->parent, REG_LIVE_READ64);
 		if (dst_regno >= 0)
 			mark_reg_stack_read(env, reg_state, off, off + size, dst_regno);
+		insn_flags = 0; /* we are not restoring spilled register */
 	}
+	if (insn_flags)
+		return push_jmp_history(env, env->cur_state, insn_flags);
 	return 0;
 }
 
@@ -6940,7 +7005,6 @@ static int check_atomic(struct bpf_verifier_env *env, int insn_idx, struct bpf_i
 			       BPF_SIZE(insn->code), BPF_WRITE, -1, true, false);
 	if (err)
 		return err;
-
 	return 0;
 }
 
@@ -16910,7 +16974,8 @@ static int is_state_visited(struct bpf_verifier_env *env, int insn_idx)
 			 * the precision needs to be propagated back in
 			 * the current state.
 			 */
-			err = err ? : push_jmp_history(env, cur);
+			if (is_jmp_point(env, env->insn_idx))
+				err = err ? : push_jmp_history(env, cur, 0);
 			err = err ? : propagate_precision(env, &sl->state);
 			if (err)
 				return err;
@@ -17135,6 +17200,9 @@ static int do_check(struct bpf_verifier_env *env)
 		u8 class;
 		int err;
 
+		/* reset current history entry on each new instruction */
+		env->cur_hist_ent = NULL;
+
 		env->prev_insn_idx = prev_insn_idx;
 		if (env->insn_idx >= insn_cnt) {
 			verbose(env, "invalid insn idx %d insn_cnt %d\n",
@@ -17174,7 +17242,7 @@ static int do_check(struct bpf_verifier_env *env)
 		}
 
 		if (is_jmp_point(env, env->insn_idx)) {
-			err = push_jmp_history(env, state);
+			err = push_jmp_history(env, state, 0);
 			if (err)
 				return err;
 		}
diff --git a/tools/testing/selftests/bpf/progs/verifier_spill_fill.c b/tools/testing/selftests/bpf/progs/verifier_spill_fill.c
index 6115520154e330..df4920da34728d 100644
--- a/tools/testing/selftests/bpf/progs/verifier_spill_fill.c
+++ b/tools/testing/selftests/bpf/progs/verifier_spill_fill.c
@@ -4,6 +4,7 @@
 #include <linux/bpf.h>
 #include <bpf/bpf_helpers.h>
 #include "bpf_misc.h"
+#include <../../../tools/include/linux/filter.h>
 
 struct {
 	__uint(type, BPF_MAP_TYPE_RINGBUF);
@@ -450,4 +451,130 @@ l0_%=:	r1 >>= 16;					\
 	: __clobber_all);
 }
 
+SEC("raw_tp")
+__log_level(2)
+__success
+__msg("fp-8=0m??mmmm")
+__msg("fp-16=00mm??mm")
+__msg("fp-24=00mm???m")
+__naked void spill_subregs_preserve_stack_zero(void)
+{
+	asm volatile (
+		"call %[bpf_get_prandom_u32];"
+
+		/* 32-bit subreg spill with ZERO, MISC, and INVALID */
+		".8byte %[fp1_u8_st_zero];"   /* ZERO, LLVM-18+: *(u8 *)(r10 -1) = 0; */
+		"*(u8 *)(r10 -2) = r0;"       /* MISC */
+		/* fp-3 and fp-4 stay INVALID */
+		"*(u32 *)(r10 -8) = r0;"
+
+		/* 16-bit subreg spill with ZERO, MISC, and INVALID */
+		".8byte %[fp10_u16_st_zero];" /* ZERO, LLVM-18+: *(u16 *)(r10 -10) = 0; */
+		"*(u16 *)(r10 -12) = r0;"     /* MISC */
+		/* fp-13 and fp-14 stay INVALID */
+		"*(u16 *)(r10 -16) = r0;"
+
+		/* 8-bit subreg spill with ZERO, MISC, and INVALID */
+		".8byte %[fp18_u16_st_zero];" /* ZERO, LLVM-18+: *(u16 *)(r18 -10) = 0; */
+		"*(u16 *)(r10 -20) = r0;"     /* MISC */
+		/* fp-21, fp-22, and fp-23 stay INVALID */
+		"*(u8 *)(r10 -24) = r0;"
+
+		"r0 = 0;"
+		"exit;"
+	:
+	: __imm(bpf_get_prandom_u32),
+	  __imm_insn(fp1_u8_st_zero, BPF_ST_MEM(BPF_B, BPF_REG_FP, -1, 0)),
+	  __imm_insn(fp10_u16_st_zero, BPF_ST_MEM(BPF_H, BPF_REG_FP, -10, 0)),
+	  __imm_insn(fp18_u16_st_zero, BPF_ST_MEM(BPF_H, BPF_REG_FP, -18, 0))
+	: __clobber_all);
+}
+
+char single_byte_buf[1] SEC(".data.single_byte_buf");
+
+SEC("raw_tp")
+__log_level(2)
+__success
+/* make sure fp-8 is all STACK_ZERO */
+__msg("2: (7a) *(u64 *)(r10 -8) = 0          ; R10=fp0 fp-8_w=00000000")
+/* but fp-16 is spilled IMPRECISE zero const reg */
+__msg("4: (7b) *(u64 *)(r10 -16) = r0        ; R0_w=0 R10=fp0 fp-16_w=0")
+/* and now check that precision propagation works even for such tricky case */
+__msg("10: (71) r2 = *(u8 *)(r10 -9)         ; R2_w=P0 R10=fp0 fp-16_w=0")
+__msg("11: (0f) r1 += r2")
+__msg("mark_precise: frame0: last_idx 11 first_idx 0 subseq_idx -1")
+__msg("mark_precise: frame0: regs=r2 stack= before 10: (71) r2 = *(u8 *)(r10 -9)")
+__msg("mark_precise: frame0: regs= stack=-16 before 9: (bf) r1 = r6")
+__msg("mark_precise: frame0: regs= stack=-16 before 8: (73) *(u8 *)(r1 +0) = r2")
+__msg("mark_precise: frame0: regs= stack=-16 before 7: (0f) r1 += r2")
+__msg("mark_precise: frame0: regs= stack=-16 before 6: (71) r2 = *(u8 *)(r10 -1)")
+__msg("mark_precise: frame0: regs= stack=-16 before 5: (bf) r1 = r6")
+__msg("mark_precise: frame0: regs= stack=-16 before 4: (7b) *(u64 *)(r10 -16) = r0")
+__msg("mark_precise: frame0: regs=r0 stack= before 3: (b7) r0 = 0")
+__naked void partial_stack_load_preserves_zeros(void)
+{
+	asm volatile (
+		/* fp-8 is all STACK_ZERO */
+		".8byte %[fp8_st_zero];" /* LLVM-18+: *(u64 *)(r10 -8) = 0; */
+
+		/* fp-16 is const zero register */
+		"r0 = 0;"
+		"*(u64 *)(r10 -16) = r0;"
+
+		/* load single U8 from non-aligned STACK_ZERO slot */
+		"r1 = %[single_byte_buf];"
+		"r2 = *(u8 *)(r10 -1);"
+		"r1 += r2;"
+		"*(u8 *)(r1 + 0) = r2;" /* this should be fine */
+
+		/* load single U8 from non-aligned ZERO REG slot */
+		"r1 = %[single_byte_buf];"
+		"r2 = *(u8 *)(r10 -9);"
+		"r1 += r2;"
+		"*(u8 *)(r1 + 0) = r2;" /* this should be fine */
+
+		/* load single U16 from non-aligned STACK_ZERO slot */
+		"r1 = %[single_byte_buf];"
+		"r2 = *(u16 *)(r10 -2);"
+		"r1 += r2;"
+		"*(u8 *)(r1 + 0) = r2;" /* this should be fine */
+
+		/* load single U16 from non-aligned ZERO REG slot */
+		"r1 = %[single_byte_buf];"
+		"r2 = *(u16 *)(r10 -10);"
+		"r1 += r2;"
+		"*(u8 *)(r1 + 0) = r2;" /* this should be fine */
+
+		/* load single U32 from non-aligned STACK_ZERO slot */
+		"r1 = %[single_byte_buf];"
+		"r2 = *(u32 *)(r10 -4);"
+		"r1 += r2;"
+		"*(u8 *)(r1 + 0) = r2;" /* this should be fine */
+
+		/* load single U32 from non-aligned ZERO REG slot */
+		"r1 = %[single_byte_buf];"
+		"r2 = *(u32 *)(r10 -12);"
+		"r1 += r2;"
+		"*(u8 *)(r1 + 0) = r2;" /* this should be fine */
+
+		/* for completeness, load U64 from STACK_ZERO slot */
+		"r1 = %[single_byte_buf];"
+		"r2 = *(u64 *)(r10 -8);"
+		"r1 += r2;"
+		"*(u8 *)(r1 + 0) = r2;" /* this should be fine */
+
+		/* for completeness, load U64 from ZERO REG slot */
+		"r1 = %[single_byte_buf];"
+		"r2 = *(u64 *)(r10 -16);"
+		"r1 += r2;"
+		"*(u8 *)(r1 + 0) = r2;" /* this should be fine */
+
+		"r0 = 0;"
+		"exit;"
+	:
+	: __imm_ptr(single_byte_buf),
+	  __imm_insn(fp8_st_zero, BPF_ST_MEM(BPF_DW, BPF_REG_FP, -8, 0))
+	: __clobber_common);
+}
+
 char _license[] SEC("license") = "GPL";
diff --git a/tools/testing/selftests/bpf/progs/verifier_subprog_precision.c b/tools/testing/selftests/bpf/progs/verifier_subprog_precision.c
index 0dfe3f8b69acff..6f5d19665cf67d 100644
--- a/tools/testing/selftests/bpf/progs/verifier_subprog_precision.c
+++ b/tools/testing/selftests/bpf/progs/verifier_subprog_precision.c
@@ -589,11 +589,24 @@ static __u64 subprog_spill_reg_precise(void)
 
 SEC("?raw_tp")
 __success __log_level(2)
-/* precision backtracking can't currently handle stack access not through r10,
- * so we won't be able to mark stack slot fp-8 as precise, and so will
- * fallback to forcing all as precise
- */
-__msg("mark_precise: frame0: falling back to forcing all scalars precise")
+__msg("10: (0f) r1 += r7")
+__msg("mark_precise: frame0: last_idx 10 first_idx 7 subseq_idx -1")
+__msg("mark_precise: frame0: regs=r7 stack= before 9: (bf) r1 = r8")
+__msg("mark_precise: frame0: regs=r7 stack= before 8: (27) r7 *= 4")
+__msg("mark_precise: frame0: regs=r7 stack= before 7: (79) r7 = *(u64 *)(r10 -8)")
+__msg("mark_precise: frame0: parent state regs= stack=-8:  R0_w=2 R6_w=1 R8_rw=map_value(map=.data.vals,ks=4,vs=16) R10=fp0 fp-8_rw=P1")
+__msg("mark_precise: frame0: last_idx 18 first_idx 0 subseq_idx 7")
+__msg("mark_precise: frame0: regs= stack=-8 before 18: (95) exit")
+__msg("mark_precise: frame1: regs= stack= before 17: (0f) r0 += r2")
+__msg("mark_precise: frame1: regs= stack= before 16: (79) r2 = *(u64 *)(r1 +0)")
+__msg("mark_precise: frame1: regs= stack= before 15: (79) r0 = *(u64 *)(r10 -16)")
+__msg("mark_precise: frame1: regs= stack= before 14: (7b) *(u64 *)(r10 -16) = r2")
+__msg("mark_precise: frame1: regs= stack= before 13: (7b) *(u64 *)(r1 +0) = r2")
+__msg("mark_precise: frame1: regs=r2 stack= before 6: (85) call pc+6")
+__msg("mark_precise: frame0: regs=r2 stack= before 5: (bf) r2 = r6")
+__msg("mark_precise: frame0: regs=r6 stack= before 4: (07) r1 += -8")
+__msg("mark_precise: frame0: regs=r6 stack= before 3: (bf) r1 = r10")
+__msg("mark_precise: frame0: regs=r6 stack= before 2: (b7) r6 = 1")
 __naked int subprog_spill_into_parent_stack_slot_precise(void)
 {
 	asm volatile (
@@ -628,14 +641,68 @@ __naked int subprog_spill_into_parent_stack_slot_precise(void)
 	);
 }
 
-__naked __noinline __used
-static __u64 subprog_with_checkpoint(void)
+SEC("?raw_tp")
+__success __log_level(2)
+__msg("17: (0f) r1 += r0")
+__msg("mark_precise: frame0: last_idx 17 first_idx 0 subseq_idx -1")
+__msg("mark_precise: frame0: regs=r0 stack= before 16: (bf) r1 = r7")
+__msg("mark_precise: frame0: regs=r0 stack= before 15: (27) r0 *= 4")
+__msg("mark_precise: frame0: regs=r0 stack= before 14: (79) r0 = *(u64 *)(r10 -16)")
+__msg("mark_precise: frame0: regs= stack=-16 before 13: (7b) *(u64 *)(r7 -8) = r0")
+__msg("mark_precise: frame0: regs=r0 stack= before 12: (79) r0 = *(u64 *)(r8 +16)")
+__msg("mark_precise: frame0: regs= stack=-16 before 11: (7b) *(u64 *)(r8 +16) = r0")
+__msg("mark_precise: frame0: regs=r0 stack= before 10: (79) r0 = *(u64 *)(r7 -8)")
+__msg("mark_precise: frame0: regs= stack=-16 before 9: (7b) *(u64 *)(r10 -16) = r0")
+__msg("mark_precise: frame0: regs=r0 stack= before 8: (07) r8 += -32")
+__msg("mark_precise: frame0: regs=r0 stack= before 7: (bf) r8 = r10")
+__msg("mark_precise: frame0: regs=r0 stack= before 6: (07) r7 += -8")
+__msg("mark_precise: frame0: regs=r0 stack= before 5: (bf) r7 = r10")
+__msg("mark_precise: frame0: regs=r0 stack= before 21: (95) exit")
+__msg("mark_precise: frame1: regs=r0 stack= before 20: (bf) r0 = r1")
+__msg("mark_precise: frame1: regs=r1 stack= before 4: (85) call pc+15")
+__msg("mark_precise: frame0: regs=r1 stack= before 3: (bf) r1 = r6")
+__msg("mark_precise: frame0: regs=r6 stack= before 2: (b7) r6 = 1")
+__naked int stack_slot_aliases_precision(void)
 {
 	asm volatile (
-		"r0 = 0;"
-		/* guaranteed checkpoint if BPF_F_TEST_STATE_FREQ is used */
-		"goto +0;"
+		"r6 = 1;"
+		/* pass r6 through r1 into subprog to get it back as r0;
+		 * this whole chain will have to be marked as precise later
+		 */
+		"r1 = r6;"
+		"call identity_subprog;"
+		/* let's setup two registers that are aliased to r10 */
+		"r7 = r10;"
+		"r7 += -8;"			/* r7 = r10 - 8 */
+		"r8 = r10;"
+		"r8 += -32;"			/* r8 = r10 - 32 */
+		/* now spill subprog's return value (a r6 -> r1 -> r0 chain)
+		 * a few times through different stack pointer regs, making
+		 * sure to use r10, r7, and r8 both in LDX and STX insns, and
+		 * *importantly* also using a combination of const var_off and
+		 * insn->off to validate that we record final stack slot
+		 * correctly, instead of relying on just insn->off derivation,
+		 * which is only valid for r10-based stack offset
+		 */
+		"*(u64 *)(r10 - 16) = r0;"
+		"r0 = *(u64 *)(r7 - 8);"	/* r7 - 8 == r10 - 16 */
+		"*(u64 *)(r8 + 16) = r0;"	/* r8 + 16 = r10 - 16 */
+		"r0 = *(u64 *)(r8 + 16);"
+		"*(u64 *)(r7 - 8) = r0;"
+		"r0 = *(u64 *)(r10 - 16);"
+		/* get ready to use r0 as an index into array to force precision */
+		"r0 *= 4;"
+		"r1 = %[vals];"
+		/* here r0->r1->r6 chain is forced to be precise and has to be
+		 * propagated back to the beginning, including through the
+		 * subprog call and all the stack spills and loads
+		 */
+		"r1 += r0;"
+		"r0 = *(u32 *)(r1 + 0);"
 		"exit;"
+		:
+		: __imm_ptr(vals)
+		: __clobber_common, "r6"
 	);
 }
 
diff --git a/tools/testing/selftests/bpf/verifier/precise.c b/tools/testing/selftests/bpf/verifier/precise.c
index 0d84dd1f38b6b0..8a2ff81d835088 100644
--- a/tools/testing/selftests/bpf/verifier/precise.c
+++ b/tools/testing/selftests/bpf/verifier/precise.c
@@ -140,10 +140,11 @@
 	.result = REJECT,
 },
 {
-	"precise: ST insn causing spi > allocated_stack",
+	"precise: ST zero to stack insn is supported",
 	.insns = {
 	BPF_MOV64_REG(BPF_REG_3, BPF_REG_10),
 	BPF_JMP_IMM(BPF_JNE, BPF_REG_3, 123, 0),
+	/* not a register spill, so we stop precision propagation for R4 here */
 	BPF_ST_MEM(BPF_DW, BPF_REG_3, -8, 0),
 	BPF_LDX_MEM(BPF_DW, BPF_REG_4, BPF_REG_10, -8),
 	BPF_MOV64_IMM(BPF_REG_0, -1),
@@ -157,11 +158,11 @@
 	mark_precise: frame0: last_idx 4 first_idx 2\
 	mark_precise: frame0: regs=r4 stack= before 4\
 	mark_precise: frame0: regs=r4 stack= before 3\
-	mark_precise: frame0: regs= stack=-8 before 2\
-	mark_precise: frame0: falling back to forcing all scalars precise\
-	force_precise: frame0: forcing r0 to be precise\
 	mark_precise: frame0: last_idx 5 first_idx 5\
-	mark_precise: frame0: parent state regs= stack=:",
+	mark_precise: frame0: parent state regs=r0 stack=:\
+	mark_precise: frame0: last_idx 4 first_idx 2\
+	mark_precise: frame0: regs=r0 stack= before 4\
+	5: R0=-1 R4=0",
 	.result = VERBOSE_ACCEPT,
 	.retval = -1,
 },
@@ -169,6 +170,8 @@
 	"precise: STX insn causing spi > allocated_stack",
 	.insns = {
 	BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_get_prandom_u32),
+	/* make later reg spill more interesting by having somewhat known scalar */
+	BPF_ALU64_IMM(BPF_AND, BPF_REG_0, 0xff),
 	BPF_MOV64_REG(BPF_REG_3, BPF_REG_10),
 	BPF_JMP_IMM(BPF_JNE, BPF_REG_3, 123, 0),
 	BPF_STX_MEM(BPF_DW, BPF_REG_3, BPF_REG_0, -8),
@@ -179,18 +182,21 @@
 	},
 	.prog_type = BPF_PROG_TYPE_XDP,
 	.flags = BPF_F_TEST_STATE_FREQ,
-	.errstr = "mark_precise: frame0: last_idx 6 first_idx 6\
+	.errstr = "mark_precise: frame0: last_idx 7 first_idx 7\
 	mark_precise: frame0: parent state regs=r4 stack=:\
-	mark_precise: frame0: last_idx 5 first_idx 3\
-	mark_precise: frame0: regs=r4 stack= before 5\
-	mark_precise: frame0: regs=r4 stack= before 4\
-	mark_precise: frame0: regs= stack=-8 before 3\
-	mark_precise: frame0: falling back to forcing all scalars precise\
-	force_precise: frame0: forcing r0 to be precise\
-	force_precise: frame0: forcing r0 to be precise\
-	force_precise: frame0: forcing r0 to be precise\
-	force_precise: frame0: forcing r0 to be precise\
-	mark_precise: frame0: last_idx 6 first_idx 6\
+	mark_precise: frame0: last_idx 6 first_idx 4\
+	mark_precise: frame0: regs=r4 stack= before 6: (b7) r0 = -1\
+	mark_precise: frame0: regs=r4 stack= before 5: (79) r4 = *(u64 *)(r10 -8)\
+	mark_precise: frame0: regs= stack=-8 before 4: (7b) *(u64 *)(r3 -8) = r0\
+	mark_precise: frame0: parent state regs=r0 stack=:\
+	mark_precise: frame0: last_idx 3 first_idx 3\
+	mark_precise: frame0: regs=r0 stack= before 3: (55) if r3 != 0x7b goto pc+0\
+	mark_precise: frame0: regs=r0 stack= before 2: (bf) r3 = r10\
+	mark_precise: frame0: regs=r0 stack= before 1: (57) r0 &= 255\
+	mark_precise: frame0: parent state regs=r0 stack=:\
+	mark_precise: frame0: last_idx 0 first_idx 0\
+	mark_precise: frame0: regs=r0 stack= before 0: (85) call bpf_get_prandom_u32#7\
+	mark_precise: frame0: last_idx 7 first_idx 7\
 	mark_precise: frame0: parent state regs= stack=:",
 	.result = VERBOSE_ACCEPT,
 	.retval = -1,