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 --- lib/string.c | 31 +++++++++++++++++++++++++++++++ 1 file changed, 31 insertions(+) (limited to 'lib/string.c') diff --git a/lib/string.c b/lib/string.c index d56f88d4a84..302efe048b0 100644 --- a/lib/string.c +++ b/lib/string.c @@ -379,6 +379,37 @@ char * strndup(const char *s, size_t n) return new; } + +/** + * strdup_const - conditionally duplicate an existing const string + * @s: the string to duplicate + * + * 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. + */ +const char *strdup_const(const char *s) +{ + if (is_kernel_rodata((unsigned long)s)) + return s; + + return strdup(s); +} + +/** + * kfree_const - conditionally free memory + * @x: pointer to the memory + * + * Function calls kfree only if @x is not in .rodata section. + */ +void kfree_const(const void *x) +{ + if (!is_kernel_rodata((unsigned long)x)) + free((void *)x); +} + #endif #ifndef __HAVE_ARCH_STRSPN -- cgit v1.2.3