linux-kernel - [PATCH v2 1/1] lib/vsprintf: Deduplicate special hex number specifier data

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Message-ID: <20251113150313.3030700-1-andriy.shevchenko@linux.intel.com>
Date: Thu, 13 Nov 2025 16:02:59 +0100
From: Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
To: linux-kernel@...r.kernel.org
Cc: Petr Mladek <pmladek@...e.com>,
	Steven Rostedt <rostedt@...dmis.org>,
	Andy Shevchenko <andriy.shevchenko@...ux.intel.com>,
	Rasmus Villemoes <linux@...musvillemoes.dk>,
	Sergey Senozhatsky <senozhatsky@...omium.org>,
	Andrew Morton <akpm@...ux-foundation.org>
Subject: [PATCH v2 1/1] lib/vsprintf: Deduplicate special hex number specifier data

Two functions use the same specifier data for the special hex number.
Almost the same as the field width is calculated on the size of the
given type. Due to that, make a compound literal macro in order to
deduplicate the rest.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
---

v2: fixed prefix in the Subject line

 lib/vsprintf.c | 26 ++++++++++----------------
 1 file changed, 10 insertions(+), 16 deletions(-)

diff --git a/lib/vsprintf.c b/lib/vsprintf.c
index 3f99834fd788..11dbf1023391 100644
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c
@@ -582,17 +582,18 @@ char *number(char *buf, char *end, unsigned long long num,
 	return buf;
 }
 
+#define special_hex_spec(size)					\
+(struct printf_spec) {						\
+	.field_width = 2 + 2 * (size),		/* 0x + hex */	\
+	.flags = SPECIAL | SMALL | ZEROPAD,			\
+	.base = 16,						\
+	.precision = -1,					\
+}
+
 static noinline_for_stack
 char *special_hex_number(char *buf, char *end, unsigned long long num, int size)
 {
-	struct printf_spec spec;
-
-	spec.field_width = 2 + 2 * size;	/* 0x + hex */
-	spec.flags = SPECIAL | SMALL | ZEROPAD;
-	spec.base = 16;
-	spec.precision = -1;
-
-	return number(buf, end, num, spec);
+	return number(buf, end, num, special_hex_spec(size));
 }
 
 static void move_right(char *buf, char *end, unsigned len, unsigned spaces)
@@ -1164,18 +1165,11 @@ char *range_string(char *buf, char *end, const struct range *range,
 	char sym[sizeof("[range 0x0123456789abcdef-0x0123456789abcdef]")];
 	char *p = sym, *pend = sym + sizeof(sym);
 
-	struct printf_spec range_spec = {
-		.field_width = 2 + 2 * sizeof(range->start), /* 0x + 2 * 8 */
-		.flags = SPECIAL | SMALL | ZEROPAD,
-		.base = 16,
-		.precision = -1,
-	};
-
 	if (check_pointer(&buf, end, range, spec))
 		return buf;
 
 	p = string_nocheck(p, pend, "[range ", default_str_spec);
-	p = hex_range(p, pend, range->start, range->end, range_spec);
+	p = hex_range(p, pend, range->start, range->end, special_hex_spec(sizeof(range->start)));
 	*p++ = ']';
 	*p = '\0';
 
-- 
2.50.1