[PATCH v1 02/19] lib/string_helpers: Introduce managed variant of kasprintf_strarray()

Andy Shevchenko andriy.shevchenko at linux.intel.com
Fri Nov 5 05:42:25 PDT 2021


Some of the users want to have easy way to allocate array of strings
that will be automatically cleaned when associated device is gone.

Introduce managed variant of kasprintf_strarray() for such use cases.

Signed-off-by: Andy Shevchenko <andriy.shevchenko at linux.intel.com>
---
 include/linux/string_helpers.h |  3 +++
 lib/string_helpers.c           | 31 +++++++++++++++++++++++++++++++
 2 files changed, 34 insertions(+)

diff --git a/include/linux/string_helpers.h b/include/linux/string_helpers.h
index f67a94013c87..7a22921c9db7 100644
--- a/include/linux/string_helpers.h
+++ b/include/linux/string_helpers.h
@@ -7,6 +7,7 @@
 #include <linux/string.h>
 #include <linux/types.h>
 
+struct device;
 struct file;
 struct task_struct;
 
@@ -103,4 +104,6 @@ char *kstrdup_quotable_file(struct file *file, gfp_t gfp);
 char **kasprintf_strarray(gfp_t gfp, const char *prefix, size_t n);
 void kfree_strarray(char **array, size_t n);
 
+char **devm_kasprintf_strarray(struct device *dev, const char *prefix, size_t n);
+
 #endif
diff --git a/lib/string_helpers.c b/lib/string_helpers.c
index 9758997c465e..90f9f1b7afec 100644
--- a/lib/string_helpers.c
+++ b/lib/string_helpers.c
@@ -10,6 +10,7 @@
 #include <linux/math64.h>
 #include <linux/export.h>
 #include <linux/ctype.h>
+#include <linux/device.h>
 #include <linux/errno.h>
 #include <linux/fs.h>
 #include <linux/limits.h>
@@ -730,6 +731,36 @@ void kfree_strarray(char **array, size_t n)
 }
 EXPORT_SYMBOL_GPL(kfree_strarray);
 
+struct strarray {
+	char **array;
+	size_t n;
+};
+
+static void devm_kfree_strarray(struct device *dev, void *res)
+{
+	struct strarray *array = res;
+
+	kfree_strarray(array->array, array->n);
+}
+
+char **devm_kasprintf_strarray(struct device *dev, const char *prefix, size_t n)
+{
+	struct strarray *ptr;
+
+	ptr = devres_alloc(devm_kfree_strarray, sizeof(*ptr), GFP_KERNEL);
+	if (!ptr)
+		return ERR_PTR(-ENOMEM);
+
+	ptr->array = kasprintf_strarray(GFP_KERNEL, prefix, n);
+	if (!ptr->array) {
+		devres_free(ptr);
+		return ERR_PTR(-ENOMEM);
+	}
+
+	return ptr->array;
+}
+EXPORT_SYMBOL_GPL(devm_kasprintf_strarray);
+
 /**
  * strscpy_pad() - Copy a C-string into a sized buffer
  * @dest: Where to copy the string to
-- 
2.33.0




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