Merge tag 'printk-for-7.2' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux

Pull printk updates from Petr Mladek:

 - Add upper case flavor for printing MAC addresses (%p[mM][U]) and use
   it in the nintendo driver

 - Fix matching of hash_pointers= parameter modes

 - Fix size check of vsprintf() field_width and precision values

 - Add check of size returned by vsprintf()

 - Add KUnit test for restricted pointer printing (%pK)

 - Some code cleanup

* tag 'printk-for-7.2' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux:
  HID: nintendo: Use %pM format specifier for MAC addresses
  vsprintf: Add upper case flavour to %p[mM]
  lib/vsprintf: replace min_t/max_t with min/max
  printk: fix typos in comments
  lib/vsprintf: Require exact hash_pointers mode matches
  vsprintf: Add test for restricted kernel pointers
  vsprintf: Only export no_hash_pointers to test module
  lib/vsprintf: Limit the returning size to INT_MAX
  lib/vsprintf: Fix to check field_width and precision

2 files changed, 74 insertions, 38 deletions

diff --git a/lib/tests/printf_kunit.c b/lib/tests/printf_kunit.c
index bb70b9cddadd..eccf041ebd56 100644
--- a/lib/tests/printf_kunit.c
+++ b/lib/tests/printf_kunit.c
@@ -319,7 +319,27 @@ symbol_ptr(struct kunit *kunittest)
 static void
 kernel_ptr(struct kunit *kunittest)
 {
-	/* We can't test this without access to kptr_restrict. */
+	switch (kptr_restrict) {
+	case 0:
+		if (no_hash_pointers) {
+			test(PTR_STR, "%pK", PTR);
+		} else {
+			char buf[PLAIN_BUF_SIZE];
+
+			plain_hash_to_buffer(kunittest, PTR, buf, PLAIN_BUF_SIZE);
+			/* %pK behaves the same as hashing */
+			test(buf, "%pK", PTR);
+		}
+		break;
+	case 1:
+		/* The KUnit kthread has all capabilities, including CAP_SYSLOG */
+		test(PTR_STR, "%pK", PTR);
+		break;
+	case 2:
+	default:
+		test(ZEROS "00000000", "%pK", PTR);
+		break;
+	}
 }
 
 static void
@@ -415,8 +435,10 @@ mac(struct kunit *kunittest)
 
 	test("2d:48:d6:fc:7a:05", "%pM", addr);
 	test("05:7a:fc:d6:48:2d", "%pMR", addr);
+	test("05:7A:FC:D6:48:2D", "%pMRU", addr);
 	test("2d-48-d6-fc-7a-05", "%pMF", addr);
 	test("2d48d6fc7a05", "%pm", addr);
+	test("2D48D6FC7A05", "%pmU", addr);
 	test("057afcd6482d", "%pmR", addr);
 }
 
diff --git a/lib/vsprintf.c b/lib/vsprintf.c
index a6169e9bcdc9..2bc6ef483576 100644
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c
@@ -59,7 +59,7 @@
 
 /* Disable pointer hashing if requested */
 bool no_hash_pointers __ro_after_init;
-EXPORT_SYMBOL_GPL(no_hash_pointers);
+EXPORT_SYMBOL_FOR_MODULES(no_hash_pointers, "printf_kunit");
 
 /*
  * Hashed pointers policy selected by "hash_pointers=..." boot param
@@ -850,6 +850,7 @@ static char *default_pointer(char *buf, char *end, const void *ptr,
 }
 
 int kptr_restrict __read_mostly;
+EXPORT_SYMBOL_FOR_MODULES(kptr_restrict, "printf_kunit");
 
 static noinline_for_stack
 char *restricted_pointer(char *buf, char *end, const void *ptr,
@@ -1201,7 +1202,7 @@ char *hex_string(char *buf, char *end, u8 *addr, struct printf_spec spec,
 	}
 
 	if (spec.field_width > 0)
-		len = min_t(int, spec.field_width, 64);
+		len = min(spec.field_width, 64);
 
 	for (i = 0; i < len; ++i) {
 		if (buf < end)
@@ -1226,7 +1227,7 @@ char *bitmap_string(char *buf, char *end, const unsigned long *bitmap,
 		    struct printf_spec spec, const char *fmt)
 {
 	const int CHUNKSZ = 32;
-	int nr_bits = max_t(int, spec.field_width, 0);
+	int nr_bits = max(spec.field_width, 0);
 	int i, chunksz;
 	bool first = true;
 
@@ -1269,7 +1270,7 @@ static noinline_for_stack
 char *bitmap_list_string(char *buf, char *end, const unsigned long *bitmap,
 			 struct printf_spec spec, const char *fmt)
 {
-	int nr_bits = max_t(int, spec.field_width, 0);
+	int nr_bits = max(spec.field_width, 0);
 	bool first = true;
 	int rbot, rtop;
 
@@ -1302,31 +1303,39 @@ char *mac_address_string(char *buf, char *end, u8 *addr,
 	char mac_addr[sizeof("xx:xx:xx:xx:xx:xx")];
 	char *p = mac_addr;
 	int i;
-	char separator;
+	char separator = ':';
 	bool reversed = false;
+	bool uc = false;
 
 	if (check_pointer(&buf, end, addr, spec))
 		return buf;
 
 	switch (fmt[1]) {
 	case 'F':
+		uc = fmt[2] == 'U';
 		separator = '-';
 		break;
 
 	case 'R':
+		uc = fmt[2] == 'U';
 		reversed = true;
-		fallthrough;
+		break;
+
+	case 'U':
+		uc = true;
+		break;
 
 	default:
-		separator = ':';
 		break;
 	}
 
 	for (i = 0; i < 6; i++) {
-		if (reversed)
-			p = hex_byte_pack(p, addr[5 - i]);
+		u8 byte = reversed ? addr[5 - i] : addr[i];
+
+		if (uc)
+			p = hex_byte_pack_upper(p, byte);
 		else
-			p = hex_byte_pack(p, addr[i]);
+			p = hex_byte_pack(p, byte);
 
 		if (fmt[0] == 'M' && i != 5)
 			*p++ = separator;
@@ -2354,13 +2363,13 @@ static int __init hash_pointers_mode_parse(char *str)
 	if (!str) {
 		pr_warn("Hash pointers mode empty; falling back to auto.\n");
 		hash_pointers_mode = HASH_PTR_AUTO;
-	} else if (strncmp(str, "auto", 4) == 0)   {
+	} else if (strcmp(str, "auto") == 0) {
 		pr_info("Hash pointers mode set to auto.\n");
 		hash_pointers_mode = HASH_PTR_AUTO;
-	} else if (strncmp(str, "never", 5) == 0) {
+	} else if (strcmp(str, "never") == 0) {
 		pr_info("Hash pointers mode set to never.\n");
 		hash_pointers_mode = HASH_PTR_NEVER;
-	} else if (strncmp(str, "always", 6) == 0) {
+	} else if (strcmp(str, "always") == 0) {
 		pr_info("Hash pointers mode set to always.\n");
 		hash_pointers_mode = HASH_PTR_ALWAYS;
 	} else {
@@ -2409,6 +2418,7 @@ early_param("no_hash_pointers", no_hash_pointers_enable);
  * - 'MF' For a 6-byte MAC FDDI address, it prints the address
  *       with a dash-separated hex notation
  * - '[mM]R' For a 6-byte MAC address, Reverse order (Bluetooth)
+ * - '[mM][FR][U]' One of the above in the upper case
  * - 'I' [46] for IPv4/IPv6 addresses printed in the usual way
  *       IPv4 uses dot-separated decimal without leading 0's (1.2.3.4)
  *       IPv6 uses colon separated network-order 16 bit hex with leading 0's
@@ -2543,6 +2553,7 @@ char *pointer(const char *fmt, char *buf, char *end, void *ptr,
 	case 'm':			/* Contiguous: 000102030405 */
 					/* [mM]F (FDDI) */
 					/* [mM]R (Reverse order; Bluetooth) */
+					/* [mM][FR][U] (One of the above in the upper case) */
 		return mac_address_string(buf, end, ptr, spec, fmt);
 	case 'I':			/* Formatted IP supported
 					 * 4:	1.2.3.4
@@ -2633,6 +2644,18 @@ static unsigned char spec_flag(unsigned char c)
 	return (c < sizeof(spec_flag_array)) ? spec_flag_array[c] : 0;
 }
 
+static void set_field_width(struct printf_spec *spec, int width)
+{
+	spec->field_width = clamp(width, -FIELD_WIDTH_MAX, FIELD_WIDTH_MAX);
+	WARN_ONCE(spec->field_width != width, "field width %d out of range", width);
+}
+
+static void set_precision(struct printf_spec *spec, int prec)
+{
+	spec->precision = clamp(prec, 0, PRECISION_MAX);
+	WARN_ONCE(spec->precision < prec, "precision %d too large", prec);
+}
+
 /*
  * Helper function to decode printf style format.
  * Each call decode a token from the format and return the
@@ -2703,7 +2726,7 @@ struct fmt format_decode(struct fmt fmt, struct printf_spec *spec)
 	spec->field_width = -1;
 
 	if (isdigit(*fmt.str))
-		spec->field_width = skip_atoi(&fmt.str);
+		set_field_width(spec, skip_atoi(&fmt.str));
 	else if (unlikely(*fmt.str == '*')) {
 		/* it's the next argument */
 		fmt.state = FORMAT_STATE_WIDTH;
@@ -2717,9 +2740,7 @@ precision:
 	if (unlikely(*fmt.str == '.')) {
 		fmt.str++;
 		if (isdigit(*fmt.str)) {
-			spec->precision = skip_atoi(&fmt.str);
-			if (spec->precision < 0)
-				spec->precision = 0;
+			set_precision(spec, skip_atoi(&fmt.str));
 		} else if (*fmt.str == '*') {
 			/* it's the next argument */
 			fmt.state = FORMAT_STATE_PRECISION;
@@ -2792,24 +2813,6 @@ qualifier:
 	return fmt;
 }
 
-static void
-set_field_width(struct printf_spec *spec, int width)
-{
-	spec->field_width = width;
-	if (WARN_ONCE(spec->field_width != width, "field width %d too large", width)) {
-		spec->field_width = clamp(width, -FIELD_WIDTH_MAX, FIELD_WIDTH_MAX);
-	}
-}
-
-static void
-set_precision(struct printf_spec *spec, int prec)
-{
-	spec->precision = prec;
-	if (WARN_ONCE(spec->precision != prec, "precision %d too large", prec)) {
-		spec->precision = clamp(prec, 0, PRECISION_MAX);
-	}
-}
-
 /*
  * Turn a 1/2/4-byte value into a 64-bit one for printing: truncate
  * as necessary and deal with signedness.
@@ -2857,6 +2860,7 @@ static unsigned long long convert_num_spec(unsigned int val, int size, struct pr
 int vsnprintf(char *buf, size_t size, const char *fmt_str, va_list args)
 {
 	char *str, *end;
+	size_t ret_size;
 	struct printf_spec spec = {0};
 	struct fmt fmt = {
 		.str = fmt_str,
@@ -2976,8 +2980,12 @@ out:
 	}
 
 	/* the trailing null byte doesn't count towards the total */
-	return str-buf;
+	ret_size = str - buf;
 
+	/* Make sure the return value is within the positive integer range */
+	if (WARN_ON_ONCE(ret_size > INT_MAX))
+		ret_size = INT_MAX;
+	return ret_size;
 }
 EXPORT_SYMBOL(vsnprintf);
 
@@ -3281,6 +3289,7 @@ int bstr_printf(char *buf, size_t size, const char *fmt_str, const u32 *bin_buf)
 	struct printf_spec spec = {0};
 	char *str, *end;
 	const char *args = (const char *)bin_buf;
+	size_t ret_size;
 
 	if (WARN_ON_ONCE(size > INT_MAX))
 		return 0;
@@ -3429,7 +3438,12 @@ out:
 #undef get_arg
 
 	/* the trailing null byte doesn't count towards the total */
-	return str - buf;
+	ret_size =  str - buf;
+
+	/* Make sure the return value is within the positive integer range */
+	if (WARN_ON_ONCE(ret_size > INT_MAX))
+		ret_size = INT_MAX;
+	return ret_size;
 }
 EXPORT_SYMBOL_GPL(bstr_printf);