kernel/linux.git/tools/include/nolibc/stdlib.h, branch v6.19.11

tools/nolibc: add option to disable runtime

2025-10-29T15:29:16+00:00

In principle, it is possible to use nolibc for only some object files in a program. In that case, the startup code in _start and _start_c is not going to be used. Add the NOLIBC_NO_RUNTIME compile time option to disable it entirely and also remove anything that depends on it. Doing this avoids warnings from modpost for UML as the _start_c code references the main function from the .init.text section while it is not inside .init itself. Signed-off-by: Benjamin Berg Signed-off-by: Thomas Weißschuh

tools/nolibc: add abs() and friends

2025-05-21T13:32:05+00:00

This is used in various selftests and will be handy when integrating those with nolibc. Signed-off-by: Thomas Weißschuh Acked-by: Willy Tarreau Link: https://lore.kernel.org/r/20250428-nolibc-misc-v2-6-3c043eeab06c@linutronix.de Signed-off-by: Thomas Weißschuh

tools/nolibc: include nolibc.h early from all header files

2025-05-21T13:31:50+00:00

Inclusion of any nolibc header file should also bring all other headers. On the other hand it should also be possible to include any nolibc header files in any order. Currently this is implemented by including the catch-all nolibc.h after the headers own definitions. This is problematic if one nolibc header depends on another one. The first header has to include the other one before defining any symbols. That in turn will include the rest of nolibc while the current header has not defined anything yet. If any other part of nolibc depends on definitions from the current header, errors are encountered. This is already the case today. Effectively nolibc can only be included in the order of nolibc.h. Restructure the way "nolibc.h" is included. Move it to the beginning of the header files and before the include guards. Now any header will behave exactly like "nolibc.h" while the include guards prevent any duplicate definitions. Signed-off-by: Thomas Weißschuh Acked-by: Willy Tarreau Link: https://lore.kernel.org/r/20250424-nolibc-header-check-v1-2-011576b6ed6f@linutronix.de

tools/nolibc: move getauxval() to sys/auxv.h

2025-04-19T12:22:22+00:00

This is the location regular userspace expects the definition. Signed-off-by: Thomas Weißschuh Acked-by: Willy Tarreau Link: https://lore.kernel.org/r/20250416-nolibc-split-sys-v1-4-a069a3f1d145@linutronix.de Signed-off-by: Thomas Weißschuh

tools/nolibc: fix integer overflow in i{64,}toa_r() and

2025-04-19T12:18:05+00:00

In twos complement the most negative number can not be negated. Fixes: b1c21e7d99cd ("tools/nolibc/stdlib: add i64toa() and u64toa()") Fixes: 66c397c4d2e1 ("tools/nolibc/stdlib: replace the ltoa() function with more efficient ones") Signed-off-by: Thomas Weißschuh Acked-by: Willy Tarreau Link: https://lore.kernel.org/r/20250419-nolibc-ubsan-v2-5-060b8a016917@weissschuh.net

tools/nolibc: add prototypes for non-static functions

2025-02-03T19:57:37+00:00

With -Wmissing-prototypes the compiler will warn about non-static functions which don't have a prototype defined. This warning doesn't make much sense for nolibc itself but for user code it is still useful. To pacify the compiler add prototypes next to the function definitions, similar to how it is handled elsewhere in the kernel. Acked-by: Willy Tarreau Link: https://lore.kernel.org/r/20250123-nolibc-prototype-v1-1-e1afc5c1999a@weissschuh.net Signed-off-by: Thomas Weißschuh

tools/nolibc: implement strtol() and friends

2024-06-29T07:44:55+00:00

The implementation always works on uintmax_t values. This is inefficient when only 32bit are needed. However for all functions this only happens for strtol() on 32bit platforms. Signed-off-by: Thomas Weißschuh Acked-by: Willy Tarreau Link: https://lore.kernel.org/r/20240425-nolibc-strtol-v1-2-bfeef7846902@weissschuh.net

tools/nolibc/stdlib: fix memory error in realloc()

2024-04-10T21:19:00+00:00

Pass user_p_len to memcpy() instead of heap->len to prevent realloc() from copying an extra sizeof(heap) bytes from beyond the allocated region. Signed-off-by: Brennan Xavier McManus Cc: stable@vger.kernel.org Reviewed-by: Ammar Faizi Fixes: 0e0ff638400be8f497a35b51a4751fd823f6bd6a ("tools/nolibc/stdlib: Implement `malloc()`, `calloc()`, `realloc()` and `free()`") Signed-off-by: Willy Tarreau Signed-off-by: Thomas Weißschuh

tools/nolibc: completely remove optional environ support

2023-08-23T02:40:22+00:00

In commit 52e423f5b93e ("tools/nolibc: export environ as a weak symbol on i386") and friends the asm startup logic was extended to directly populate the "environ" array. This makes it impossible for "environ" to be dropped by the linker. Therefore also drop the other logic to handle non-present "environ". Also add a testcase to validate the initialization of environ. Signed-off-by: Thomas Weißschuh Signed-off-by: Willy Tarreau

tools/nolibc: use inline syntax

2023-06-09T18:46:07+00:00

When building in strict C89 mode the "inline" keyword is unknown. While "__inline__" is non-standard it is used by the kernel headers themselves. So the used compilers would have to support it or the users shim it with a #define. Signed-off-by: Thomas Weißschuh Signed-off-by: Willy Tarreau Signed-off-by: Paul E. McKenney