linux-kernel - [PATCH v1 1/1] lib/string: Use strchr() in strpbrk()

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Message-Id: <20230127155135.27153-1-andriy.shevchenko@linux.intel.com>
Date:   Fri, 27 Jan 2023 17:51:35 +0200
From:   Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
To:     Kees Cook <keescook@...omium.org>, linux-kernel@...r.kernel.org
Cc:     Andy Shevchenko <andy@...nel.org>,
        Rasmus Villemoes <linux@...musvillemoes.dk>,
        Andrew Morton <akpm@...ux-foundation.org>,
        Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
Subject: [PATCH v1 1/1] lib/string: Use strchr() in strpbrk()

Use strchr() instead of open coding it as it's done elsewhere in
the same file. Either we will have similar to what it was or possibly
better performance in case architecture implements its own strchr().

Memory wise on x86_64 bloat-o-meter shows the following

  Function           old     new   delta
  strsep             111     102      -9
  Total: Before=2763, After=2754, chg -0.33%

Signed-off-by: Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
---
 lib/string.c | 10 ++++------
 1 file changed, 4 insertions(+), 6 deletions(-)

diff --git a/lib/string.c b/lib/string.c
index 4fb566ea610f..3d55ef890106 100644
--- a/lib/string.c
+++ b/lib/string.c
@@ -480,13 +480,11 @@ EXPORT_SYMBOL(strcspn);
  */
 char *strpbrk(const char *cs, const char *ct)
 {
-	const char *sc1, *sc2;
+	const char *sc;
 
-	for (sc1 = cs; *sc1 != '\0'; ++sc1) {
-		for (sc2 = ct; *sc2 != '\0'; ++sc2) {
-			if (*sc1 == *sc2)
-				return (char *)sc1;
-		}
+	for (sc = cs; *sc != '\0'; ++sc) {
+		if (strchr(ct, *sc))
+			return (char *)sc;
 	}
 	return NULL;
 }
-- 
2.39.0