user/sven/linux.git/lib/string.c, branch v6.12.4

move asm/unaligned.h to linux/unaligned.h

2024-10-02T21:23:23Z

asm/unaligned.h is always an include of asm-generic/unaligned.h; might as well move that thing to linux/unaligned.h and include that - there's nothing arch-specific in that header. auto-generated by the following: for i in `git grep -l -w asm/unaligned.h`; do sed -i -e "s/asm\/unaligned.h/linux\/unaligned.h/" $i done for i in `git grep -l -w asm-generic/unaligned.h`; do sed -i -e "s/asm-generic\/unaligned.h/linux\/unaligned.h/" $i done git mv include/asm-generic/unaligned.h include/linux/unaligned.h git mv tools/include/asm-generic/unaligned.h tools/include/linux/unaligned.h sed -i -e "/unaligned.h/d" include/asm-generic/Kbuild sed -i -e "s/__ASM_GENERIC/__LINUX/" include/linux/unaligned.h tools/include/linux/unaligned.h

string: Allow 2-argument strscpy()

2024-02-21T04:47:32Z

Using sizeof(dst) for the "size" argument in strscpy() is the overwhelmingly common case. Instead of requiring this everywhere, allow a 2-argument version to be used that will use the sizeof() internally. There are other functions in the kernel with optional arguments[1], so this isn't unprecedented, and improves readability. Update and relocate the kern-doc for strscpy() too, and drop __HAVE_ARCH_STRSCPY as it is unused. Adjust ARCH=um build to notice the changed export name, as it doesn't do full header includes for the string helpers. This could additionally let us save a few hundred lines of code: 1177 files changed, 2455 insertions(+), 3026 deletions(-) with a treewide cleanup using Coccinelle: @needless_arg@ expression DST, SRC; @@ strscpy(DST, SRC -, sizeof(DST) ) Link: https://elixir.bootlin.com/linux/v6.7/source/include/linux/pci.h#L1517 [1] Reviewed-by: Justin Stitt Cc: Andy Shevchenko Cc: linux-hardening@vger.kernel.org Signed-off-by: Kees Cook

lib/string: shrink lib/string.i via IWYU

2024-02-01T17:47:59Z

This diff uses an open source tool include-what-you-use (IWYU) to modify the include list, changing indirect includes to direct includes. IWYU is implemented using the IWYUScripts github repository which is a tool that is currently undergoing development. These changes seek to improve build times. This change to lib/string.c resulted in a preprocessed size of lib/string.i from 26371 lines to 5321 lines (-80%) for the x86 defconfig. Link: https://github.com/ClangBuiltLinux/IWYUScripts Reviewed-by: Kees Cook Signed-off-by: Tanzir Hasan Reviewed-by: Andy Shevchenko Link: https://lore.kernel.org/r/20231226-libstringheader-v6-2-80aa08c7652c@google.com Signed-off-by: Kees Cook

string: Remove strlcpy()

2024-01-19T19:59:11Z

With all the users of strlcpy() removed[1] from the kernel, remove the API, self-tests, and other references. Leave mentions in Documentation (about its deprecation), and in checkpatch.pl (to help migrate host-only tools/ usage). Long live strscpy(). Link: https://github.com/KSPP/linux/issues/89 [1] Cc: Azeem Shaikh Cc: Andrew Morton Cc: Andy Whitcroft Cc: Joe Perches Cc: Dwaipayan Ray Cc: Lukas Bulwahn Cc: linux-hardening@vger.kernel.org Reviewed-by: Andy Shevchenko Signed-off-by: Kees Cook

string: use __builtin_memcpy() in strlcpy/strlcat

2023-06-01T18:24:50Z

lib/string.c is built with -ffreestanding, which prevents the compiler from replacing certain functions with calls to their library versions. On the other hand, this also prevents Clang and GCC from instrumenting calls to memcpy() when building with KASAN, KCSAN or KMSAN: - KASAN normally replaces memcpy() with __asan_memcpy() with the additional cc-param,asan-kernel-mem-intrinsic-prefix=1; - KCSAN and KMSAN replace memcpy() with __tsan_memcpy() and __msan_memcpy() by default. To let the tools catch memory accesses from strlcpy/strlcat, replace the calls to memcpy() with __builtin_memcpy(), which KASAN, KCSAN and KMSAN are able to replace even in -ffreestanding mode. This preserves the behavior in normal builds (__builtin_memcpy() ends up being replaced with memcpy()), and does not introduce new instrumentation in unwanted places, as strlcpy/strlcat are already instrumented. Suggested-by: Marco Elver Signed-off-by: Alexander Potapenko Reviewed-by: Marco Elver Link: https://lore.kernel.org/all/20230224085942.1791837-1-elver@google.com/ Acked-by: Kees Cook Signed-off-by: Kees Cook Link: https://lore.kernel.org/r/20230530083911.1104336-1-glider@google.com

lib/string: Use strchr() in strpbrk()

2023-01-27T19:42:57Z

Use strchr() instead of open coding it as it's done elsewhere in the same file. Either we will have similar to what it was or possibly better performance in case architecture implements its own strchr(). Memory wise on x86_64 bloat-o-meter shows the following Function old new delta strsep 111 102 -9 Total: Before=2763, After=2754, chg -0.33% Signed-off-by: Andy Shevchenko Signed-off-by: Kees Cook Link: https://lore.kernel.org/r/20230127155135.27153-1-andriy.shevchenko@linux.intel.com

string: Rewrite and add more kern-doc for the str*() functions

2022-10-28T23:07:57Z

While there were varying degrees of kern-doc for various str*()-family functions, many needed updating and clarification, or to just be entirely written. Update (and relocate) existing kern-doc and add missing functions, sadly shaking my head at how many times I have written "Do not use this function". Include the results in the core kernel API doc. Cc: Bagas Sanjaya Cc: Andy Shevchenko Cc: Rasmus Villemoes Cc: Andrew Morton Cc: linux-hardening@vger.kernel.org Tested-by: Akira Yokosawa Link: https://lore.kernel.org/lkml/9b0cf584-01b3-3013-b800-1ef59fe82476@gmail.com Signed-off-by: Kees Cook

kmsan: disable strscpy() optimization under KMSAN

2022-10-03T21:03:22Z

Disable the efficient 8-byte reading under KMSAN to avoid false positives. Link: https://lkml.kernel.org/r/20220915150417.722975-26-glider@google.com Signed-off-by: Alexander Potapenko Cc: Alexander Viro Cc: Alexei Starovoitov Cc: Andrey Konovalov Cc: Andrey Konovalov Cc: Andy Lutomirski Cc: Arnd Bergmann Cc: Borislav Petkov Cc: Christoph Hellwig Cc: Christoph Lameter Cc: David Rientjes Cc: Dmitry Vyukov Cc: Eric Biggers Cc: Eric Biggers Cc: Eric Dumazet Cc: Greg Kroah-Hartman Cc: Herbert Xu Cc: Ilya Leoshkevich Cc: Ingo Molnar Cc: Jens Axboe Cc: Joonsoo Kim Cc: Kees Cook Cc: Marco Elver Cc: Mark Rutland Cc: Matthew Wilcox Cc: Michael S. Tsirkin Cc: Pekka Enberg Cc: Peter Zijlstra Cc: Petr Mladek Cc: Stephen Rothwell Cc: Steven Rostedt Cc: Thomas Gleixner Cc: Vasily Gorbik Cc: Vegard Nossum Cc: Vlastimil Babka Signed-off-by: Andrew Morton

lib/string.c: simplify str[c]spn

2022-04-29T21:38:01Z

Use strchr(), which makes them a lot shorter, and more obviously symmetric in their treatment of accept/reject. It also saves a little bit of .text; bloat-o-meter for an arm build says Function old new delta strcspn 92 76 -16 strspn 108 76 -32 While here, also remove a stray empty line before EXPORT_SYMBOL(). Link: https://lkml.kernel.org/r/20220328224119.3003834-2-linux@rasmusvillemoes.dk Signed-off-by: Rasmus Villemoes Cc: Andy Shevchenko Signed-off-by: Andrew Morton

lib/string: Move helper functions out of string.c

2021-09-25T15:20:49Z

The core functions of string.c are those that may be implemented by per-architecture functions, or overloaded by FORTIFY_SOURCE. As a result, it needs to be built with __NO_FORTIFY. Without this, macros will collide with function declarations. This was accidentally working due to -ffreestanding (on some architectures). Make this deterministic by explicitly setting __NO_FORTIFY and move all the helper functions into string_helpers.c so that they gain the fortification coverage they had been missing. Cc: Andrew Morton Cc: Nick Desaulniers Cc: Andy Lavr Cc: Nathan Chancellor Cc: Alexey Dobriyan Cc: Stephen Rothwell Cc: Bartosz Golaszewski Acked-by: Andy Shevchenko Signed-off-by: Kees Cook