From 139f5292e7985d0326a1d18eee88720255e423dc Mon Sep 17 00:00:00 2001 From: Casey Connolly Date: Wed, 1 Apr 2026 16:15:19 +0200 Subject: string: add strdup_const and kstrdup_const Extend Linux compat by adding kstrdup_const(), backed by lib/string.c. This leverages U-Boots .rodata section on ARM64 to avoid pointlessly duplicating const strings. This is used by the Linux CCF_FULL port and may be useful elsewhere in U-Boot. Signed-off-by: Casey Connolly --- include/linux/compat.h | 13 +++++++++++++ include/linux/string.h | 2 ++ 2 files changed, 15 insertions(+) (limited to 'include/linux') diff --git a/include/linux/compat.h b/include/linux/compat.h index 62381451617..d4ba4d0088a 100644 --- a/include/linux/compat.h +++ b/include/linux/compat.h @@ -67,6 +67,19 @@ static inline void vfree(const void *addr) free((void *)addr); } +/** + * kstrdup_const - conditionally duplicate an existing const string + * @s: the string to duplicate + * @gfp: the GFP mask used in the kmalloc() call when allocating memory + * + * Note: Strings allocated by kstrdup_const should be freed by kfree_const and + * must not be passed to krealloc(). + * + * Return: source string if it is in .rodata section otherwise + * fallback to kstrdup. + */ +#define kstrdup_const(s, gfp) strdup_const(s) + struct kmem_cache { int sz; }; struct kmem_cache *get_mem(int element_sz); diff --git a/include/linux/string.h b/include/linux/string.h index d943fcce690..a8a6cf4af50 100644 --- a/include/linux/string.h +++ b/include/linux/string.h @@ -104,6 +104,8 @@ size_t strcspn(const char *s, const char *reject); #ifndef __HAVE_ARCH_STRDUP extern char * strdup(const char *); extern char * strndup(const char *, size_t); +extern const char *strdup_const(const char *s); +extern void kfree_const(const void *x); #endif #ifndef __HAVE_ARCH_STRSWAB extern char * strswab(const char *); -- cgit v1.2.3