From: Darrick J. Wong <djwong@kernel.org>
Date: Thu, 21 Nov 2024 00:24:27 +0000 (-0800)
Subject: libfrog: add memchr_inv
X-Git-Tag: v6.13.0~121
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=16ddcc41229c7af098e0083b4d0afd1b94715d06;p=thirdparty%2Fxfsprogs-dev.git

libfrog: add memchr_inv

Add this kernel function so we can use it in userspace.

Signed-off-by: "Darrick J. Wong" <djwong@kernel.org>
[hch: split from a larger patch]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
---

diff --git a/libfrog/util.c b/libfrog/util.c
index 8fb10cf8..46047571 100644
--- a/libfrog/util.c
+++ b/libfrog/util.c
@@ -22,3 +22,17 @@ log2_roundup(unsigned int i)
 	}
 	return rval;
 }
+
+void *
+memchr_inv(const void *start, int c, size_t bytes)
+{
+	const unsigned char	*p = start;
+
+	while (bytes > 0) {
+		if (*p != (unsigned char)c)
+			return (void *)p;
+		bytes--;
+	}
+
+	return NULL;
+}
diff --git a/libfrog/util.h b/libfrog/util.h
index 5df95e69..8b4ee7c1 100644
--- a/libfrog/util.h
+++ b/libfrog/util.h
@@ -6,6 +6,8 @@
 #ifndef __LIBFROG_UTIL_H__
 #define __LIBFROG_UTIL_H__
 
+#include <sys/types.h>
+
 unsigned int	log2_roundup(unsigned int i);
 
 #define min_t(type,x,y) \
@@ -13,4 +15,6 @@ unsigned int	log2_roundup(unsigned int i);
 #define max_t(type,x,y) \
 	({ type __x = (x); type __y = (y); __x > __y ? __x: __y; })
 
+void *memchr_inv(const void *start, int c, size_t bytes);
+
 #endif /* __LIBFROG_UTIL_H__ */