Merge tag 'at24-4.16-updates-for-wolfram' of git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux into i2c/for-4.16

"AT24 updates for 4.16 merge window

The driver has been converted to using regmap instead of raw i2c and
smbus calls which shrank the code significantly.

Device tree binding document has been cleaned up. Device tree support in
the driver has been improved and we now support all at24 models as well
as two new DT properties (no-read-rollover and wp-gpios).

We no longer user unreadable magic values for driver data as the way it
was implemented caused problems for some EEPROM models - we switched to
regular structs.

Aside from that, there's a bunch of coding style fixes and minor
improvements all over the place."

4 files changed, 185 insertions, 118 deletions

diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c
index b9f8686a84cf..86b50aa26ee8 100644
--- a/kernel/bpf/core.c
+++ b/kernel/bpf/core.c
@@ -1447,7 +1447,8 @@ int bpf_prog_array_length(struct bpf_prog_array __rcu *progs)
 	rcu_read_lock();
 	prog = rcu_dereference(progs)->progs;
 	for (; *prog; prog++)
-		cnt++;
+		if (*prog != &dummy_bpf_prog.prog)
+			cnt++;
 	rcu_read_unlock();
 	return cnt;
 }
diff --git a/kernel/bpf/hashtab.c b/kernel/bpf/hashtab.c
index e469e05c8e83..3905d4bc5b80 100644
--- a/kernel/bpf/hashtab.c
+++ b/kernel/bpf/hashtab.c
@@ -114,6 +114,7 @@ static void htab_free_elems(struct bpf_htab *htab)
 		pptr = htab_elem_get_ptr(get_htab_elem(htab, i),
 					 htab->map.key_size);
 		free_percpu(pptr);
+		cond_resched();
 	}
 free_elems:
 	bpf_map_area_free(htab->elems);
@@ -159,6 +160,7 @@ static int prealloc_init(struct bpf_htab *htab)
 			goto free_elems;
 		htab_elem_set_ptr(get_htab_elem(htab, i), htab->map.key_size,
 				  pptr);
+		cond_resched();
 	}
 
 skip_percpu_elems:
diff --git a/kernel/bpf/offload.c b/kernel/bpf/offload.c
index 68ec884440b7..8455b89d1bbf 100644
--- a/kernel/bpf/offload.c
+++ b/kernel/bpf/offload.c
@@ -1,3 +1,18 @@
+/*
+ * Copyright (C) 2017 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
+ * source tree.
+ *
+ * THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES PROVIDE THE PROGRAM "AS IS"
+ * WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING,
+ * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE. THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE
+ * OF THE PROGRAM IS WITH YOU. SHOULD THE PROGRAM PROVE DEFECTIVE, YOU ASSUME
+ * THE COST OF ALL NECESSARY SERVICING, REPAIR OR CORRECTION.
+ */
+
 #include <linux/bpf.h>
 #include <linux/bpf_verifier.h>
 #include <linux/bug.h>
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index d4593571c404..04b24876cd23 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -1059,6 +1059,11 @@ static int check_ptr_alignment(struct bpf_verifier_env *env,
 		break;
 	case PTR_TO_STACK:
 		pointer_desc = "stack ";
+		/* The stack spill tracking logic in check_stack_write()
+		 * and check_stack_read() relies on stack accesses being
+		 * aligned.
+		 */
+		strict = true;
 		break;
 	default:
 		break;
@@ -1067,6 +1072,29 @@ static int check_ptr_alignment(struct bpf_verifier_env *env,
 					   strict);
 }
 
+/* truncate register to smaller size (in bytes)
+ * must be called with size < BPF_REG_SIZE
+ */
+static void coerce_reg_to_size(struct bpf_reg_state *reg, int size)
+{
+	u64 mask;
+
+	/* clear high bits in bit representation */
+	reg->var_off = tnum_cast(reg->var_off, size);
+
+	/* fix arithmetic bounds */
+	mask = ((u64)1 << (size * 8)) - 1;
+	if ((reg->umin_value & ~mask) == (reg->umax_value & ~mask)) {
+		reg->umin_value &= mask;
+		reg->umax_value &= mask;
+	} else {
+		reg->umin_value = 0;
+		reg->umax_value = mask;
+	}
+	reg->smin_value = reg->umin_value;
+	reg->smax_value = reg->umax_value;
+}
+
 /* check whether memory at (regno + off) is accessible for t = (read | write)
  * if t==write, value_regno is a register which value is stored into memory
  * if t==read, value_regno is a register which will receive the value from memory
@@ -1200,9 +1228,7 @@ static int check_mem_access(struct bpf_verifier_env *env, int insn_idx, u32 regn
 	if (!err && size < BPF_REG_SIZE && value_regno >= 0 && t == BPF_READ &&
 	    regs[value_regno].type == SCALAR_VALUE) {
 		/* b/h/w load zero-extends, mark upper bits as known 0 */
-		regs[value_regno].var_off =
-			tnum_cast(regs[value_regno].var_off, size);
-		__update_reg_bounds(&regs[value_regno]);
+		coerce_reg_to_size(&regs[value_regno], size);
 	}
 	return err;
 }
@@ -1282,6 +1308,7 @@ static int check_stack_boundary(struct bpf_verifier_env *env, int regno,
 		tnum_strn(tn_buf, sizeof(tn_buf), regs[regno].var_off);
 		verbose(env, "invalid variable stack read R%d var_off=%s\n",
 			regno, tn_buf);
+		return -EACCES;
 	}
 	off = regs[regno].off + regs[regno].var_off.value;
 	if (off >= 0 || off < -MAX_BPF_STACK || off + access_size > 0 ||
@@ -1674,7 +1701,13 @@ static int check_call(struct bpf_verifier_env *env, int func_id, int insn_idx)
 		return -EINVAL;
 	}
 
+	/* With LD_ABS/IND some JITs save/restore skb from r1. */
 	changes_data = bpf_helper_changes_pkt_data(fn->func);
+	if (changes_data && fn->arg1_type != ARG_PTR_TO_CTX) {
+		verbose(env, "kernel subsystem misconfigured func %s#%d: r1 != ctx\n",
+			func_id_name(func_id), func_id);
+		return -EINVAL;
+	}
 
 	memset(&meta, 0, sizeof(meta));
 	meta.pkt_access = fn->pkt_access;
@@ -1766,14 +1799,6 @@ static int check_call(struct bpf_verifier_env *env, int func_id, int insn_idx)
 	return 0;
 }
 
-static void coerce_reg_to_32(struct bpf_reg_state *reg)
-{
-	/* clear high 32 bits */
-	reg->var_off = tnum_cast(reg->var_off, 4);
-	/* Update bounds */
-	__update_reg_bounds(reg);
-}
-
 static bool signed_add_overflows(s64 a, s64 b)
 {
 	/* Do the add in u64, where overflow is well-defined */
@@ -1794,6 +1819,41 @@ static bool signed_sub_overflows(s64 a, s64 b)
 	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)
+{
+	bool known = tnum_is_const(reg->var_off);
+	s64 val = reg->var_off.value;
+	s64 smin = reg->smin_value;
+
+	if (known && (val >= BPF_MAX_VAR_OFF || val <= -BPF_MAX_VAR_OFF)) {
+		verbose(env, "math between %s pointer and %lld is not allowed\n",
+			reg_type_str[type], val);
+		return false;
+	}
+
+	if (reg->off >= BPF_MAX_VAR_OFF || reg->off <= -BPF_MAX_VAR_OFF) {
+		verbose(env, "%s pointer offset %d is not allowed\n",
+			reg_type_str[type], reg->off);
+		return false;
+	}
+
+	if (smin == S64_MIN) {
+		verbose(env, "math between %s pointer and register with unbounded min value is not allowed\n",
+			reg_type_str[type]);
+		return false;
+	}
+
+	if (smin >= BPF_MAX_VAR_OFF || smin <= -BPF_MAX_VAR_OFF) {
+		verbose(env, "value %lld makes %s pointer be out of bounds\n",
+			smin, reg_type_str[type]);
+		return false;
+	}
+
+	return true;
+}
+
 /* Handles arithmetic on a pointer and a scalar: computes new min/max and var_off.
  * Caller should also handle BPF_MOV case separately.
  * If we return -EACCES, caller may want to try again treating pointer as a
@@ -1830,29 +1890,25 @@ static int adjust_ptr_min_max_vals(struct bpf_verifier_env *env,
 
 	if (BPF_CLASS(insn->code) != BPF_ALU64) {
 		/* 32-bit ALU ops on pointers produce (meaningless) scalars */
-		if (!env->allow_ptr_leaks)
-			verbose(env,
-				"R%d 32-bit pointer arithmetic prohibited\n",
-				dst);
+		verbose(env,
+			"R%d 32-bit pointer arithmetic prohibited\n",
+			dst);
 		return -EACCES;
 	}
 
 	if (ptr_reg->type == PTR_TO_MAP_VALUE_OR_NULL) {
-		if (!env->allow_ptr_leaks)
-			verbose(env, "R%d pointer arithmetic on PTR_TO_MAP_VALUE_OR_NULL prohibited, null-check it first\n",
-				dst);
+		verbose(env, "R%d pointer arithmetic on PTR_TO_MAP_VALUE_OR_NULL prohibited, null-check it first\n",
+			dst);
 		return -EACCES;
 	}
 	if (ptr_reg->type == CONST_PTR_TO_MAP) {
-		if (!env->allow_ptr_leaks)
-			verbose(env, "R%d pointer arithmetic on CONST_PTR_TO_MAP prohibited\n",
-				dst);
+		verbose(env, "R%d pointer arithmetic on CONST_PTR_TO_MAP prohibited\n",
+			dst);
 		return -EACCES;
 	}
 	if (ptr_reg->type == PTR_TO_PACKET_END) {
-		if (!env->allow_ptr_leaks)
-			verbose(env, "R%d pointer arithmetic on PTR_TO_PACKET_END prohibited\n",
-				dst);
+		verbose(env, "R%d pointer arithmetic on PTR_TO_PACKET_END prohibited\n",
+			dst);
 		return -EACCES;
 	}
 
@@ -1862,6 +1918,10 @@ static int adjust_ptr_min_max_vals(struct bpf_verifier_env *env,
 	dst_reg->type = ptr_reg->type;
 	dst_reg->id = ptr_reg->id;
 
+	if (!check_reg_sane_offset(env, off_reg, ptr_reg->type) ||
+	    !check_reg_sane_offset(env, ptr_reg, ptr_reg->type))
+		return -EINVAL;
+
 	switch (opcode) {
 	case BPF_ADD:
 		/* We can take a fixed offset as long as it doesn't overflow
@@ -1915,9 +1975,8 @@ static int adjust_ptr_min_max_vals(struct bpf_verifier_env *env,
 	case BPF_SUB:
 		if (dst_reg == off_reg) {
 			/* scalar -= pointer.  Creates an unknown scalar */
-			if (!env->allow_ptr_leaks)
-				verbose(env, "R%d tried to subtract pointer from scalar\n",
-					dst);
+			verbose(env, "R%d tried to subtract pointer from scalar\n",
+				dst);
 			return -EACCES;
 		}
 		/* We don't allow subtraction from FP, because (according to
@@ -1925,9 +1984,8 @@ static int adjust_ptr_min_max_vals(struct bpf_verifier_env *env,
 		 * be able to deal with it.
 		 */
 		if (ptr_reg->type == PTR_TO_STACK) {
-			if (!env->allow_ptr_leaks)
-				verbose(env, "R%d subtraction from stack pointer prohibited\n",
-					dst);
+			verbose(env, "R%d subtraction from stack pointer prohibited\n",
+				dst);
 			return -EACCES;
 		}
 		if (known && (ptr_reg->off - smin_val ==
@@ -1976,28 +2034,30 @@ static int adjust_ptr_min_max_vals(struct bpf_verifier_env *env,
 	case BPF_AND:
 	case BPF_OR:
 	case BPF_XOR:
-		/* bitwise ops on pointers are troublesome, prohibit for now.
-		 * (However, in principle we could allow some cases, e.g.
-		 * ptr &= ~3 which would reduce min_value by 3.)
-		 */
-		if (!env->allow_ptr_leaks)
-			verbose(env, "R%d bitwise operator %s on pointer prohibited\n",
-				dst, bpf_alu_string[opcode >> 4]);
+		/* bitwise ops on pointers are troublesome, prohibit. */
+		verbose(env, "R%d bitwise operator %s on pointer prohibited\n",
+			dst, bpf_alu_string[opcode >> 4]);
 		return -EACCES;
 	default:
 		/* other operators (e.g. MUL,LSH) produce non-pointer results */
-		if (!env->allow_ptr_leaks)
-			verbose(env, "R%d pointer arithmetic with %s operator prohibited\n",
-				dst, bpf_alu_string[opcode >> 4]);
+		verbose(env, "R%d pointer arithmetic with %s operator prohibited\n",
+			dst, bpf_alu_string[opcode >> 4]);
 		return -EACCES;
 	}
 
+	if (!check_reg_sane_offset(env, dst_reg, ptr_reg->type))
+		return -EINVAL;
+
 	__update_reg_bounds(dst_reg);
 	__reg_deduce_bounds(dst_reg);
 	__reg_bound_offset(dst_reg);
 	return 0;
 }
 
+/* WARNING: This function does calculations on 64-bit values, but the actual
+ * execution may occur on 32-bit values. Therefore, things like bitshifts
+ * need extra checks in the 32-bit case.
+ */
 static int adjust_scalar_min_max_vals(struct bpf_verifier_env *env,
 				      struct bpf_insn *insn,
 				      struct bpf_reg_state *dst_reg,
@@ -2008,12 +2068,8 @@ 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;
+	u64 insn_bitness = (BPF_CLASS(insn->code) == BPF_ALU64) ? 64 : 32;
 
-	if (BPF_CLASS(insn->code) != BPF_ALU64) {
-		/* 32-bit ALU ops are (32,32)->64 */
-		coerce_reg_to_32(dst_reg);
-		coerce_reg_to_32(&src_reg);
-	}
 	smin_val = src_reg.smin_value;
 	smax_val = src_reg.smax_value;
 	umin_val = src_reg.umin_value;
@@ -2021,6 +2077,12 @@ static int adjust_scalar_min_max_vals(struct bpf_verifier_env *env,
 	src_known = tnum_is_const(src_reg.var_off);
 	dst_known = tnum_is_const(dst_reg->var_off);
 
+	if (!src_known &&
+	    opcode != BPF_ADD && opcode != BPF_SUB && opcode != BPF_AND) {
+		__mark_reg_unknown(dst_reg);
+		return 0;
+	}
+
 	switch (opcode) {
 	case BPF_ADD:
 		if (signed_add_overflows(dst_reg->smin_value, smin_val) ||
@@ -2149,9 +2211,9 @@ static int adjust_scalar_min_max_vals(struct bpf_verifier_env *env,
 		__update_reg_bounds(dst_reg);
 		break;
 	case BPF_LSH:
-		if (umax_val > 63) {
-			/* Shifts greater than 63 are undefined.  This includes
-			 * shifts by a negative number.
+		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;
@@ -2177,27 +2239,29 @@ static int adjust_scalar_min_max_vals(struct bpf_verifier_env *env,
 		__update_reg_bounds(dst_reg);
 		break;
 	case BPF_RSH:
-		if (umax_val > 63) {
-			/* Shifts greater than 63 are undefined.  This includes
-			 * shifts by a negative number.
+		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;
 		}
-		/* BPF_RSH is an unsigned shift, so make the appropriate casts */
-		if (dst_reg->smin_value < 0) {
-			if (umin_val) {
-				/* Sign bit will be cleared */
-				dst_reg->smin_value = 0;
-			} else {
-				/* Lost sign bit information */
-				dst_reg->smin_value = S64_MIN;
-				dst_reg->smax_value = S64_MAX;
-			}
-		} else {
-			dst_reg->smin_value =
-				(u64)(dst_reg->smin_value) >> umax_val;
-		}
+		/* 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->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);
@@ -2213,6 +2277,12 @@ static int adjust_scalar_min_max_vals(struct bpf_verifier_env *env,
 		break;
 	}
 
+	if (BPF_CLASS(insn->code) != BPF_ALU64) {
+		/* 32-bit ALU ops are (32,32)->32 */
+		coerce_reg_to_size(dst_reg, 4);
+		coerce_reg_to_size(&src_reg, 4);
+	}
+
 	__reg_deduce_bounds(dst_reg);
 	__reg_bound_offset(dst_reg);
 	return 0;
@@ -2227,7 +2297,6 @@ static int adjust_reg_min_max_vals(struct bpf_verifier_env *env,
 	struct bpf_reg_state *regs = cur_regs(env), *dst_reg, *src_reg;
 	struct bpf_reg_state *ptr_reg = NULL, off_reg = {0};
 	u8 opcode = BPF_OP(insn->code);
-	int rc;
 
 	dst_reg = &regs[insn->dst_reg];
 	src_reg = NULL;
@@ -2238,43 +2307,29 @@ static int adjust_reg_min_max_vals(struct bpf_verifier_env *env,
 		if (src_reg->type != SCALAR_VALUE) {
 			if (dst_reg->type != SCALAR_VALUE) {
 				/* Combining two pointers by any ALU op yields
-				 * an arbitrary scalar.
+				 * an arbitrary scalar. Disallow all math except
+				 * pointer subtraction
 				 */
-				if (!env->allow_ptr_leaks) {
-					verbose(env, "R%d pointer %s pointer prohibited\n",
-						insn->dst_reg,
-						bpf_alu_string[opcode >> 4]);
-					return -EACCES;
+				if (opcode == BPF_SUB){
+					mark_reg_unknown(env, regs, insn->dst_reg);
+					return 0;
 				}
-				mark_reg_unknown(env, regs, insn->dst_reg);
-				return 0;
+				verbose(env, "R%d pointer %s pointer prohibited\n",
+					insn->dst_reg,
+					bpf_alu_string[opcode >> 4]);
+				return -EACCES;
 			} else {
 				/* scalar += pointer
 				 * This is legal, but we have to reverse our
 				 * src/dest handling in computing the range
 				 */
-				rc = adjust_ptr_min_max_vals(env, insn,
-							     src_reg, dst_reg);
-				if (rc == -EACCES && env->allow_ptr_leaks) {
-					/* scalar += unknown scalar */
-					__mark_reg_unknown(&off_reg);
-					return adjust_scalar_min_max_vals(
-							env, insn,
-							dst_reg, off_reg);
-				}
-				return rc;
+				return adjust_ptr_min_max_vals(env, insn,
+							       src_reg, dst_reg);
 			}
 		} else if (ptr_reg) {
 			/* pointer += scalar */
-			rc = adjust_ptr_min_max_vals(env, insn,
-						     dst_reg, src_reg);
-			if (rc == -EACCES && env->allow_ptr_leaks) {
-				/* unknown scalar += scalar */
-				__mark_reg_unknown(dst_reg);
-				return adjust_scalar_min_max_vals(
-						env, insn, dst_reg, *src_reg);
-			}
-			return rc;
+			return adjust_ptr_min_max_vals(env, insn,
+						       dst_reg, src_reg);
 		}
 	} else {
 		/* Pretend the src is a reg with a known value, since we only
@@ -2283,17 +2338,9 @@ static int adjust_reg_min_max_vals(struct bpf_verifier_env *env,
 		off_reg.type = SCALAR_VALUE;
 		__mark_reg_known(&off_reg, insn->imm);
 		src_reg = &off_reg;
-		if (ptr_reg) { /* pointer += K */
-			rc = adjust_ptr_min_max_vals(env, insn,
-						     ptr_reg, src_reg);
-			if (rc == -EACCES && env->allow_ptr_leaks) {
-				/* unknown scalar += K */
-				__mark_reg_unknown(dst_reg);
-				return adjust_scalar_min_max_vals(
-						env, insn, dst_reg, off_reg);
-			}
-			return rc;
-		}
+		if (ptr_reg) /* pointer += K */
+			return adjust_ptr_min_max_vals(env, insn,
+						       ptr_reg, src_reg);
 	}
 
 	/* Got here implies adding two SCALAR_VALUEs */
@@ -2390,17 +2437,20 @@ static int check_alu_op(struct bpf_verifier_env *env, struct bpf_insn *insn)
 					return -EACCES;
 				}
 				mark_reg_unknown(env, regs, insn->dst_reg);
-				/* high 32 bits are known zero. */
-				regs[insn->dst_reg].var_off = tnum_cast(
-						regs[insn->dst_reg].var_off, 4);
-				__update_reg_bounds(&regs[insn->dst_reg]);
+				coerce_reg_to_size(&regs[insn->dst_reg], 4);
 			}
 		} else {
 			/* case: R = imm
 			 * remember the value we stored into this reg
 			 */
 			regs[insn->dst_reg].type = SCALAR_VALUE;
-			__mark_reg_known(regs + insn->dst_reg, insn->imm);
+			if (BPF_CLASS(insn->code) == BPF_ALU64) {
+				__mark_reg_known(regs + insn->dst_reg,
+						 insn->imm);
+			} else {
+				__mark_reg_known(regs + insn->dst_reg,
+						 (u32)insn->imm);
+			}
 		}
 
 	} else if (opcode > BPF_END) {
@@ -3431,15 +3481,14 @@ static bool regsafe(struct bpf_reg_state *rold, struct bpf_reg_state *rcur,
 			return range_within(rold, rcur) &&
 			       tnum_in(rold->var_off, rcur->var_off);
 		} else {
-			/* if we knew anything about the old value, we're not
-			 * equal, because we can't know anything about the
-			 * scalar value of the pointer in the new value.
+			/* We're trying to use a pointer in place of a scalar.
+			 * Even if the scalar was unbounded, this could lead to
+			 * pointer leaks because scalars are allowed to leak
+			 * while pointers are not. We could make this safe in
+			 * special cases if root is calling us, but it's
+			 * probably not worth the hassle.
 			 */
-			return rold->umin_value == 0 &&
-			       rold->umax_value == U64_MAX &&
-			       rold->smin_value == S64_MIN &&
-			       rold->smax_value == S64_MAX &&
-			       tnum_is_unknown(rold->var_off);
+			return false;
 		}
 	case PTR_TO_MAP_VALUE:
 		/* If the new min/max/var_off satisfy the old ones and