tools/nolibc: add support for [v]sscanf()

These functions are used often, also in selftests.
sscanf() itself is also used by kselftest.h itself.

The implementation is limited and only supports nume

tools/nolibc: add support for [v]sscanf()

These functions are used often, also in selftests.
sscanf() itself is also used by kselftest.h itself.

The implementation is limited and only supports numeric arguments.

Acked-by: Willy Tarreau <w@1wt.eu>
Link: https://lore.kernel.org/r/20250209-nolibc-scanf-v2-1-c29dea32f1cd@weissschuh.net
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>

show more ...

tools/nolibc: add support for 32-bit s390

32-bit s390 is very close to the existing 64-bit implementation.

Some special handling is necessary as there is neither LLVM nor
QEMU support. Also the ker

tools/nolibc: add support for 32-bit s390

32-bit s390 is very close to the existing 64-bit implementation.

Some special handling is necessary as there is neither LLVM nor
QEMU support. Also the kernel itself can not build natively for 32-bit
s390, so instead the test program is executed with a 64-bit kernel.

Acked-by: Willy Tarreau <w@1wt.eu>
Link: https://lore.kernel.org/r/20250206-nolibc-s390-v2-2-991ad97e3d58@weissschuh.net
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>

show more ...

selftests/nolibc: rename s390 to s390x

Support for 32-bit s390 is about to be added.
As "s39032" would look horrible, use the another naming scheme.
32-bit s390 is "s390" and 64-bit s390 is "s390x",

selftests/nolibc: rename s390 to s390x

Support for 32-bit s390 is about to be added.
As "s39032" would look horrible, use the another naming scheme.
32-bit s390 is "s390" and 64-bit s390 is "s390x",
similar to how it is handled in various toolchain components.

Acked-by: Willy Tarreau <w@1wt.eu>
Link: https://lore.kernel.org/r/20250206-nolibc-s390-v2-1-991ad97e3d58@weissschuh.net
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>

show more ...

selftests/nolibc: only run constructor tests on nolibc

The nolibc testsuite can be run against other libcs to test for
interoperability. Some aspects of the constructor execution are not
standardize

selftests/nolibc: only run constructor tests on nolibc

The nolibc testsuite can be run against other libcs to test for
interoperability. Some aspects of the constructor execution are not
standardized and musl does not provide all tested feature, for one it
does not provide arguments to the constructors, anymore?

Skip the constructor tests on non-nolibc configurations.

Acked-by: Willy Tarreau <w@1wt.eu>
Link: https://lore.kernel.org/r/20250212-nolibc-test-constructor-v1-1-c963875b3da4@weissschuh.net
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>

show more ...

selftests/nolibc: split up architecture list in run-tests.sh

The list is getting overly long and any modifications introduce a lot of
noise and are prone to conflicts. Split the string into a bash a

selftests/nolibc: split up architecture list in run-tests.sh

The list is getting overly long and any modifications introduce a lot of
noise and are prone to conflicts. Split the string into a bash array
and break that into multiple lines.

Link: https://lore.kernel.org/r/20250211-nolibc-test-archs-v1-1-8e55aa3369cf@weissschuh.net
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>

show more ...

tools/nolibc: add support for directory access

Add an implementation for directory access operations.
To keep nolibc itself allocation-free, a "DIR *" does not point to any
data, but directly encode

tools/nolibc: add support for directory access

Add an implementation for directory access operations.
To keep nolibc itself allocation-free, a "DIR *" does not point to any
data, but directly encodes a filedescriptor number, equivalent to "FILE *".
Without any per-directory storage it is not possible to implement
readdir() POSIX confirming. Instead only readdir_r() is provided.
While readdir_r() is deprecated in glibc, the reasons for that are
not applicable to nolibc.

Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Link: https://lore.kernel.org/r/20250209-nolibc-dir-v2-2-57cc1da8558b@weissschuh.net
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>

show more ...

selftests/nolibc: always keep test kernel configuration up to date

Avoid using a stale test kernel configuration by always synchronizing
it to the current source tree.
kbuild is smart enough to avoi

selftests/nolibc: always keep test kernel configuration up to date

Avoid using a stale test kernel configuration by always synchronizing
it to the current source tree.
kbuild is smart enough to avoid spurious rebuilds.

Shuffle the code around a bit to keep all the commands with side-effects
together.

Acked-by: Willy Tarreau <w@1wt.eu>
Link: https://lore.kernel.org/r/20250123-nolibc-config-v2-5-5701c35995d6@weissschuh.net
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>

show more ...

selftests/nolibc: execute defconfig before other targets

Some targets use the test kernel configuration.
Executing defconfig in the same make invocation as those targets results
in errors as the con

selftests/nolibc: execute defconfig before other targets

Some targets use the test kernel configuration.
Executing defconfig in the same make invocation as those targets results
in errors as the configuration may be in an inconsistent state during
reconfiguration.
Avoid this by introducing ordering dependencies between the defconfig
and some other targets.

Acked-by: Willy Tarreau <w@1wt.eu>
Link: https://lore.kernel.org/r/20250123-nolibc-config-v2-4-5701c35995d6@weissschuh.net
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>

show more ...

selftests/nolibc: drop call to mrproper target

"mrproper" unnecessarily cleans a lot of files.
kbuild is smart enough to handle changed configurations,
so the cleanup is not necessary and only leads

selftests/nolibc: drop call to mrproper target

"mrproper" unnecessarily cleans a lot of files.
kbuild is smart enough to handle changed configurations,
so the cleanup is not necessary and only leads to excessive rebuilds.

Acked-by: Willy Tarreau <w@1wt.eu>
Link: https://lore.kernel.org/r/20250123-nolibc-config-v2-3-5701c35995d6@weissschuh.net
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>

show more ...

selftests/nolibc: drop call to prepare target

The "prepare" target does not need to be run manually.
kbuild knows when to use it on its own and the target is not even
documented.

Acked-by: Willy Ta

selftests/nolibc: drop call to prepare target

The "prepare" target does not need to be run manually.
kbuild knows when to use it on its own and the target is not even
documented.

Acked-by: Willy Tarreau <w@1wt.eu>
Link: https://lore.kernel.org/r/20250123-nolibc-config-v2-2-5701c35995d6@weissschuh.net
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>

show more ...

selftests/nolibc: drop mips32be EXTRACONFIG

kbuild already contains logic to merge predefines snippets into a
defconfig file. For MIPS a snippet for big-endian is already provided.

Link: https://lo

selftests/nolibc: drop mips32be EXTRACONFIG

kbuild already contains logic to merge predefines snippets into a
defconfig file. For MIPS a snippet for big-endian is already provided.

Link: https://lore.kernel.org/r/20250123-nolibc-config-v2-1-5701c35995d6@weissschuh.net
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>

show more ...

selftests/nolibc: enable -Wmissing-prototypes

User code may want to use this compiler flag.
Make sure it is supported by nolibc.

Acked-by: Willy Tarreau <w@1wt.eu>
Link: https://lore.kernel.org/r/2

selftests/nolibc: enable -Wmissing-prototypes

User code may want to use this compiler flag.
Make sure it is supported by nolibc.

Acked-by: Willy Tarreau <w@1wt.eu>
Link: https://lore.kernel.org/r/20250123-nolibc-prototype-v1-3-e1afc5c1999a@weissschuh.net
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>

show more ...

selftests/nolibc: ignore -Wmissing-prototypes

To make sure nolibc itself is compatible with -Wmissing-prototypes the
compiler flag should be enabled when building nolibc-test.
However some of its fu

selftests/nolibc: ignore -Wmissing-prototypes

To make sure nolibc itself is compatible with -Wmissing-prototypes the
compiler flag should be enabled when building nolibc-test.
However some of its functions are non-static to ease debugging [0],
triggering the compiler warning.

Disable the warning inside nolibc-test while still enabling it for
nolibc itself.

[0] https://lore.kernel.org/lkml/ZMjM0UPRAqoC+goY@1wt.eu/

Acked-by: Willy Tarreau <w@1wt.eu>
Link: https://lore.kernel.org/r/20250123-nolibc-prototype-v1-2-e1afc5c1999a@weissschuh.net
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>

show more ...