[v2,1/4] lib/string_helpers: Add kstrdup_and_replace() helper

Commit Message

Andy Shevchenko Aug. 4, 2023, 2:39 p.m. UTC

Duplicate a NULL-terminated string and replace all occurrences of
the old character with a new one. In other words, provide functionality
of kstrdup() + strreplace().

Signed-off-by: Andy Shevchenko <[e-mail]>
---
 include/linux/string_helpers.h |  2 ++
 lib/string_helpers.c           | 15 +++++++++++++++
 2 files changed, 17 insertions(+)

Patch

diff --git a/include/linux/string_helpers.h b/include/linux/string_helpers.h
index 789ab30045da..9d1f5bb74dd5 100644
--- a/include/linux/string_helpers.h
+++ b/include/linux/string_helpers.h
@@ -109,6 +109,8 @@  char *kstrdup_quotable(const char *src, gfp_t gfp);
 char *kstrdup_quotable_cmdline(struct task_struct *task, gfp_t gfp);
 char *kstrdup_quotable_file(struct file *file, gfp_t gfp);
 
+char *kstrdup_and_replace(const char *src, char old, char new, gfp_t gfp);
+
 char **kasprintf_strarray(gfp_t gfp, const char *prefix, size_t n);
 void kfree_strarray(char **array, size_t n);
 
diff --git a/lib/string_helpers.c b/lib/string_helpers.c
index d3b1dd718daf..9982344cca34 100644
--- a/lib/string_helpers.c
+++ b/lib/string_helpers.c
@@ -719,6 +719,21 @@  char *kstrdup_quotable_file(struct file *file, gfp_t gfp)
 }
 EXPORT_SYMBOL_GPL(kstrdup_quotable_file);
 
+/*
+ * Returns duplicate string in which the @old characters are replaced by @new.
+ */
+char *kstrdup_and_replace(const char *src, char old, char new, gfp_t gfp)
+{
+	char *dst;
+
+	dst = kstrdup(src, gfp);
+	if (!dst)
+		return NULL;
+
+	return strreplace(dst, old, new);
+}
+EXPORT_SYMBOL_GPL(kstrdup_and_replace);
+
 /**
  * kasprintf_strarray - allocate and fill array of sequential strings
  * @gfp: flags for the slab allocator