kernel/linux.git/tools/include/nolibc, branch linux-7.0.y

tools/nolibc: avoid -Wundef warning for __STDC_VERSION__

2026-05-23T11:08:32+00:00

[ Upstream commit 3eb97c4cbd4d874e7e327ec512f6169934e12b8a ] With -std=c89 the macro __STDC_VERSION__ is not defined. While undefined identifiers in '#if' directives are assumed to be '0', with -Wundef a warning is emitted. Avoid the warning by explicitly falling back to '0' if __STDC_VERSION__ is not provided by the preprocessor. Fixes: 37219aa5b123 ("tools/nolibc: add __nolibc_static_assert()") Signed-off-by: Thomas Weißschuh Acked-by: Willy Tarreau Link: https://patch.msgid.link/20260318-nolibc-wundef-v1-1-fcb7f9ac7298@weissschuh.net Signed-off-by: Sasha Levin

tools/nolibc: MIPS: fix clobbers of 'lo' and 'hi' registers on different ISAs

2026-05-23T11:08:32+00:00

[ Upstream commit e83b07dc8c05a55d02057b1484724a0b188f6f8d ] All MIPS ISAs before r6 use the 'lo' and 'hi' special registers. These are clobbered by system calls and need to be marked as such to avoid miscompilations. Currently nolibc ties the clobbers to the ABI. But this is wrong and leads to ISA<->ABI combinations which are not handled correctly, leading to compiler errors or miscompilations. Handle all different combinations of ABI and ISA. Fixes: a6a2a8a42972 ("tools/nolibc: MIPS: add support for N64 and N32 ABIs") Fixes: 66b6f755ad45 ("rcutorture: Import a copy of nolibc") Suggested-by: Maciej W. Rozycki Link: https://lore.kernel.org/lkml/alpine.DEB.2.21.2603141744240.55200@angie.orcam.me.uk/ Signed-off-by: Thomas Weißschuh Link: https://patch.msgid.link/20260317-nolibc-mips-clobber-v2-1-5b9a97761a9e@linutronix.de Signed-off-by: Thomas Weißschuh Signed-off-by: Sasha Levin

tools/nolibc/printf: Move snprintf length check to callback

2026-05-23T11:08:32+00:00

[ Upstream commit 4045e7b19bbf7338452cda11e64cfe7ae3361964 ] Move output truncation to the snprintf() callback. This simplifies the main code and fixes truncation of padded fields. Add a zero length callback to 'finalise' the buffer rather than doing it in snprintf() itself. Fixes: e90ce42e81381 ("tools/nolibc: implement width padding in printf()") Signed-off-by: David Laight Acked-by: Willy Tarreau Link: https://patch.msgid.link/20260302101815.3043-3-david.laight.linux@gmail.com [Thomas: clean up Fixes trailer] Signed-off-by: Thomas Weißschuh Signed-off-by: Sasha Levin

tools/nolibc/printf: Change variables 'c' to 'ch' and 'tmpbuf[]' to 'outbuf[]'

2026-05-23T11:08:32+00:00

[ Upstream commit f675ae28fcdf7db93a8c1a6964f062725b1e06a0 ] Changing 'c' makes the code slightly easier to read because the variable stands out from the single character literals (especially 'c'). Change tmpbuf[] to outbuf[] because 'out' points into it. The following patches pretty much rewrite the function so the churn is limited. Signed-off-by: David Laight Acked-by: Willy Tarreau Link: https://patch.msgid.link/20260223101735.2922-7-david.laight.linux@gmail.com Signed-off-by: Thomas Weißschuh Stable-dep-of: 4045e7b19bbf ("tools/nolibc/printf: Move snprintf length check to callback") Signed-off-by: Sasha Levin

tools/nolibc: Add fseek() to stdio.h

2026-01-11T11:47:47+00:00

A very basic wrapper around lseek() that implements fseek(). Signed-off-by: Daniel Palmer Link: https://patch.msgid.link/20260105023629.1502801-3-daniel@thingy.jp Signed-off-by: Thomas Weißschuh

tools/nolibc: Add fread() to stdio.h

2026-01-11T11:47:47+00:00

Add a very basic version of fread() like we already have for fwrite(). Signed-off-by: Daniel Palmer Link: https://patch.msgid.link/20260105023629.1502801-2-daniel@thingy.jp Signed-off-by: Thomas Weißschuh

tools/nolibc: align sys_vfork() with sys_fork()

2026-01-06T11:08:10+00:00

Currently the generic variants of sys_fork() and sys_vfork() differ in both they precedence of used system calls and the usage of sys_clone() vs sys_clone3(). While the interface of clone3() in sys_vfork() is more consistent over different architectures, qemu-user does not support it, making testing harder. We already handle the different clone() interfaces for sys_fork() in the architecture-specific headers, and can do so also for sys_vfork(). In fact SPARC already has such handling and only s390 is currently missing. Signed-off-by: Thomas Weißschuh Acked-by: Willy Tarreau Link: https://patch.msgid.link/20260104-nolibc-vfork-v1-1-a63464b9e4e6@weissschuh.net

selftests/nolibc: add static assertions around time types handling

2026-01-06T11:08:08+00:00

The nolibc system call wrappers expect the libc types to be compatible to the kernel types. Make sure these expectations hold at compile-time. Signed-off-by: Thomas Weißschuh Acked-by: Willy Tarreau Reviewed-by: Arnd Bergmann Link: https://patch.msgid.link/20251220-nolibc-uapi-types-v3-14-c662992f75d7@weissschuh.net

tools/nolibc: add __nolibc_static_assert()

2026-01-06T11:08:08+00:00

Add a wrapper for _Static_assert() to use within nolibc. While _Static_assert() itself was only standardized in C11, in GCC and clang dialects it is also available in older standards. Link: https://lore.kernel.org/lkml/20251203192330.GA12995@1wt.eu/ Signed-off-by: Thomas Weißschuh Acked-by: Willy Tarreau Reviewed-by: Arnd Bergmann Link: https://patch.msgid.link/20251220-nolibc-uapi-types-v3-13-c662992f75d7@weissschuh.net

tools/nolibc: add compiler version detection macros

2026-01-06T11:08:07+00:00

Some upcoming logic needs to depend on the version of GCC or clang. Add some helper macros to keep the conditionals readable. Signed-off-by: Thomas Weißschuh Acked-by: Willy Tarreau Reviewed-by: Arnd Bergmann Link: https://patch.msgid.link/20251220-nolibc-uapi-types-v3-12-c662992f75d7@weissschuh.net