u-boot.git/include/linux/string.h, branch main

Merge patch series "add memdup_nul(), use it and memdup() in a few places"

2026-05-12T21:41:52Z

Rasmus Villemoes says: There are quite a few places where we allocate X+1 bytes, initialize the first X bytes via memcpy() and then set the last byte to 0. The kernel has a helper for that, kmemdup_nul(). Introduce a similar one, and start making use of it in a few places. Also the existing memdup() helper can be put to more use. There are lots more places one could modify. But for code shared with host tools, one would need to do some refactoring, putting memdup() and memdup_nul() in their own str-util.c TU which could then also be included in the tools build. Link: https://lore.kernel.org/r/20260421075439.16696-1-ravi@prevas.dk

lib/string.c: introduce memdup_nul() helper

2026-05-12T21:38:00Z

This is completely analogous to the linux kernel's kmemdup_nul() helper, apart from the lack of the gfp_t argument: Allocate a buffer of size {len}+1, copy {len} bytes from the given buffer, and add a final nul byte. This pattern exists in a number of places, so this helper can reduce some boilerplate code. Reviewed-by: Simon Glass Signed-off-by: Rasmus Villemoes

lib/string.c: drop pointless __HAVE_ARCH_STRDUP

2026-05-12T21:38:00Z

There has never been an arch-specific optimized implementation of str[n]dup, nor is there likely to ever be one, because unlike their cousins strlen(), strcpy() and similar that simply read/write the src/dst, the dup functions by definition involve memory allocation. So drop this irrelevant cpp guard. Reviewed-by: Simon Glass Signed-off-by: Rasmus Villemoes

string: fix prototype of memdup()

2026-05-12T21:38:00Z

It doesn't make sense to restrict memdup() to only return char* pointers, especially when it is already defined to accept void*. This makes it uglier to use to e.g. duplicate a struct. Make it return void*, just as kmemdup() does in the kernel (and which our kmemdup() in fact also does). While in here, make a small optimization: memcpy() is defined to return the destination register, so we write this in a way that the compiler may do a tail call. Reviewed-by: Simon Glass Signed-off-by: Rasmus Villemoes

string: add strdup_const and kstrdup_const

2026-04-21T17:19:49Z

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: implement strnstr()

2025-02-12T18:37:12Z

Implement library function strnstr(). Implement strstr() using strnstr(). Sort the includes. Signed-off-by: Heinrich Schuchardt Reviewed-by: Ilias Apalodimas [jf: replace by , folded from next patch] Signed-off-by: Jerome Forissier

include: linux: Remove duplicate newlines

2024-07-29T21:01:04Z

Drop all duplicate newlines. No functional change. Signed-off-by: Marek Vasut

doc: replace @return by Return:

2022-01-19T17:11:34Z

Sphinx expects Return: and not @return to indicate a return value. find . -name '*.c' -exec \ sed -i 's/^\(\s\)\*\(\s*\)@return\(\s\)/\1*\2Return:\3/' {} \; find . -name '*.h' -exec \ sed -i 's/^\(\s\)\*\(\s*\)@return\(\s\)/\1*\2Return:\3/' {} \; Signed-off-by: Heinrich Schuchardt

lib: Add memdup()

2021-10-08T19:53:26Z

Add a function to duplicate a memory region, a little like strdup(). Signed-off-by: Simon Glass

lib: string: Implement strlcat

2021-04-12T21:44:55Z

This introduces strlcat, which provides a safer interface than strncat. It never copies more than its size bytes, including the terminating nul. In addition, it never reads past dest[size - 1], even if dest is not nul-terminated. This also removes the stub for dwc3 now that we have a proper implementation. Signed-off-by: Sean Anderson Reviewed-by: Simon Glass