From 418e0a3551bbef5b221705b0e5b8412cdc0afd39 Mon Sep 17 00:00:00 2001 From: Andy Shevchenko Date: Fri, 5 Nov 2021 14:42:24 +0200 Subject: lib/string_helpers: Introduce kasprintf_strarray() We have a few users already that basically want to have array of sequential strings to be allocated and filled. Provide a helper for them (basically adjusted version from gpio-mockup.c). Signed-off-by: Andy Shevchenko Reviewed-by: Linus Walleij --- include/linux/string_helpers.h | 1 + lib/string_helpers.c | 33 +++++++++++++++++++++++++++++++++ 2 files changed, 34 insertions(+) diff --git a/include/linux/string_helpers.h b/include/linux/string_helpers.h index 4ba39e1403b2..f67a94013c87 100644 --- a/include/linux/string_helpers.h +++ b/include/linux/string_helpers.h @@ -100,6 +100,7 @@ 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 **kasprintf_strarray(gfp_t gfp, const char *prefix, size_t n); void kfree_strarray(char **array, size_t n); #endif diff --git a/lib/string_helpers.c b/lib/string_helpers.c index d5d008f5b1d9..9758997c465e 100644 --- a/lib/string_helpers.c +++ b/lib/string_helpers.c @@ -674,6 +674,39 @@ char *kstrdup_quotable_file(struct file *file, gfp_t gfp) } EXPORT_SYMBOL_GPL(kstrdup_quotable_file); +/** + * kasprintf_strarray - allocate and fill array of sequential strings + * @gfp: flags for the slab allocator + * @prefix: prefix to be used + * @n: amount of lines to be allocated and filled + * + * Allocates and fills @n strings using pattern "%s-%zu", where prefix + * is provided by caller. The caller is responsible to free them with + * kfree_strarray() after use. + * + * Returns array of strings or NULL when memory can't be allocated. + */ +char **kasprintf_strarray(gfp_t gfp, const char *prefix, size_t n) +{ + char **names; + size_t i; + + names = kcalloc(n + 1, sizeof(char *), gfp); + if (!names) + return NULL; + + for (i = 0; i < n; i++) { + names[i] = kasprintf(gfp, "%s-%zu", prefix, i); + if (!names[i]) { + kfree_strarray(names, i); + return NULL; + } + } + + return names; +} +EXPORT_SYMBOL_GPL(kasprintf_strarray); + /** * kfree_strarray - free a number of dynamically allocated strings contained * in an array and the array itself -- cgit v1.2.3