u-boot.git/lib/string.c, 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: implement strdup() and strndup() in terms of memdup_nul()

2026-05-12T21:38:00Z

With the addition of memdup_nul(), strdup() and strndup() can be implemented as one-liners. While not required by POSIX or C, do keep the behaviour of gracefully accepting a NULL source and simply return NULL. Reviewed-by: Simon Glass Signed-off-by: Rasmus Villemoes

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

lib: Mark memcpy() and memmove() as relocation code

2025-02-03T22:01:36Z

Mark these functions as needed by relocation. These functions are used to copy data while relocating the next-phase image. Drop the 'safe' versions from SPL as they are not needed. Change the static array to a local one, to avoid link errors when trying to access the data. Signed-off-by: Simon Glass

lib: Remove duplicate newlines

2024-07-15T18:12:18Z

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

Revert "lib: string: Fix strlcpy return value", fix callers

2023-08-08T21:05:43Z

Both the Linux kernel and libbsd agree that strlcpy() should always return strlen(src) and not include the NUL termination. The incorrect U-Boot implementation makes it impossible to check the return value for truncation, and breaks code written with the usual implementation in mind (for example, fdtdec_add_reserved_memory() was subtly broken). I reviewed all callers of strlcpy() and strlcat() and fixed them according to my understanding of the intended function. This reverts commit d3358ecc54be0bc3b4dd11f7a63eab0a2842f772 and adds related fixes. Fixes: d3358ecc54be ("lib: string: Fix strlcpy return value") Signed-off-by: Matthias Schiffer Reviewed-by: Simon Glass Reviewed-by: Sean Anderson