tools/nolibc: support UBSAN on gcc

The UBSAN implementation in gcc requires a slightly different function
attribute to skip instrumentation.

Extend __nolibc_no_sanitize_undefined to also handle gcc

tools/nolibc: support UBSAN on gcc

The UBSAN implementation in gcc requires a slightly different function
attribute to skip instrumentation.

Extend __nolibc_no_sanitize_undefined to also handle gcc.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Link: https://patch.msgid.link/20260408-nolibc-gcc-15-v1-2-330d0c40f894@weissschuh.net

show more ...

tools/nolibc: create __nolibc_no_sanitize_ubsan

The logic to disable UBSAN will become a bit more complicated.
Move it out into compiler.h, so crt.h stays readable.

Signed-off-by: Thomas Weißschuh

tools/nolibc: create __nolibc_no_sanitize_ubsan

The logic to disable UBSAN will become a bit more complicated.
Move it out into compiler.h, so crt.h stays readable.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Link: https://patch.msgid.link/20260408-nolibc-gcc-15-v1-1-330d0c40f894@weissschuh.net

show more ...

tools/nolibc: add byteorder conversions

Add some standard functions to convert between different byte orders.
Conveniently the UAPI headers provide all the necessary functionality.

Signed-off-by: T

tools/nolibc: add byteorder conversions

Add some standard functions to convert between different byte orders.
Conveniently the UAPI headers provide all the necessary functionality.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Acked-by: Willy Tarreau <w@1wt.eu>
Link: https://patch.msgid.link/20260405-nolibc-bswap-v1-1-f7699ca9cee0@weissschuh.net

show more ...

tools/nolibc: add the _syscall() macro

The standard syscall() function or macro uses the libc return value
convention. Errors returned from the kernel as negative values are
stored in errno and -1 i

tools/nolibc: add the _syscall() macro

The standard syscall() function or macro uses the libc return value
convention. Errors returned from the kernel as negative values are
stored in errno and -1 is returned. Users who want to avoid using
errno don't have a way to call raw syscalls and check the returned
error.

Add a new macro _syscall() which works like the standard syscall()
but passes through the return value from the kernel unchanged.
The naming scheme and return values match the named _sys_foo()
system call wrappers already part of nolibc.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Acked-by: Willy Tarreau <w@1wt.eu>
Link: https://patch.msgid.link/20260405-nolibc-syscall-v1-3-e5b12bc63211@weissschuh.net

show more ...

tools/nolibc: move the call to __sysret() into syscall()

__sysret() transforms the return value from the kernel into the libc
return value convention. There is no reason for it to be called in the
m

tools/nolibc: move the call to __sysret() into syscall()

__sysret() transforms the return value from the kernel into the libc
return value convention. There is no reason for it to be called in the
middle of the internals of the syscall() implementation macros.

Move the call up, directly into syscall(), to make the code simpler.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Acked-by: Willy Tarreau <w@1wt.eu>
Link: https://patch.msgid.link/20260405-nolibc-syscall-v1-2-e5b12bc63211@weissschuh.net

show more ...

tools/nolibc: rename the internal macros used in syscall()

These macros are the internal implementation of syscall().
They can not be used by users. Align them with the standard naming
scheme for in

tools/nolibc: rename the internal macros used in syscall()

These macros are the internal implementation of syscall().
They can not be used by users. Align them with the standard naming
scheme for internal symbols.

The current name also prevents the addition of an application-usable
_syscall() symbol.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Acked-by: Willy Tarreau <w@1wt.eu>
Link: https://patch.msgid.link/20260405-nolibc-syscall-v1-1-e5b12bc63211@weissschuh.net

show more ...

tools/nolibc: check for overflow in calloc() without divisions

On some architectures without native division instructions
the division can generate calls into libgcc/compiler-rt.
This library might

tools/nolibc: check for overflow in calloc() without divisions

On some architectures without native division instructions
the division can generate calls into libgcc/compiler-rt.
This library might not be available, so its use should be avoided.

Use the compiler builtin to check for overflows without needing a
division. The builtin has been available since GCC 3 and clang 3.8.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Acked-by: Willy Tarreau <w@1wt.eu>
Link: https://patch.msgid.link/20260404-nolibc-asprintf-v2-1-17d2d0df9763@weissschuh.net

show more ...

tools/nolibc: add support for asprintf()

Add support for dynamically allocating formatted strings through
asprintf() and vasprintf().

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Acked-by

tools/nolibc: add support for asprintf()

Add support for dynamically allocating formatted strings through
asprintf() and vasprintf().

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Acked-by: Willy Tarreau <w@1wt.eu>
Link: https://patch.msgid.link/20260401-nolibc-asprintf-v1-3-46292313439f@weissschuh.net

show more ...

tools/nolibc: use __builtin_offsetof()

The current custom implementation of offsetof() fails UBSAN:
runtime error: member access within null pointer of type 'struct ...'
This means that all its user

tools/nolibc: use __builtin_offsetof()

The current custom implementation of offsetof() fails UBSAN:
runtime error: member access within null pointer of type 'struct ...'
This means that all its users, including container_of(), free() and
realloc(), fail.

Use __builtin_offsetof() instead which does not have this issue and
has been available since GCC 4 and clang 3.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Acked-by: Willy Tarreau <w@1wt.eu>
Link: https://patch.msgid.link/20260401-nolibc-asprintf-v1-1-46292313439f@weissschuh.net

show more ...

tools/nolibc: use makedev() in fstatat()

fstatat() contains two open-coded copies of makedev() to handle minor
numbers >= 256. Now that the regular makedev() handles both large minor
and major numbe

tools/nolibc: use makedev() in fstatat()

fstatat() contains two open-coded copies of makedev() to handle minor
numbers >= 256. Now that the regular makedev() handles both large minor
and major numbers correctly use the common function.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Acked-by: Willy Tarreau <w@1wt.eu>
Link: https://patch.msgid.link/20260404-nolibc-makedev-v2-6-456a429bf60c@weissschuh.net

show more ...

tools/nolibc: handle all major and minor numbers in makedev() and friends

Remove the limitation of only handling small major and minor numbers.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net

tools/nolibc: handle all major and minor numbers in makedev() and friends

Remove the limitation of only handling small major and minor numbers.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Acked-by: Willy Tarreau <w@1wt.eu>
Link: https://patch.msgid.link/20260404-nolibc-makedev-v2-5-456a429bf60c@weissschuh.net

show more ...

tools/nolibc: make dev_t 64 bits wide

statx() returns both 32-bit minor and major numbers. For both of them to
fit into the 'dev_t' in 'struct stat', that needs to be 64 bits wide.

The other uses o

tools/nolibc: make dev_t 64 bits wide

statx() returns both 32-bit minor and major numbers. For both of them to
fit into the 'dev_t' in 'struct stat', that needs to be 64 bits wide.

The other uses of 'dev_t' in nolibc are makedev() and friends and
mknod(). makedev() and friends are going to be adapted in an upcoming
commit and mknod() will silently truncate 'dev_t' to 'unsigned int' in
the kernel, similar to other libcs.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Acked-by: Willy Tarreau <w@1wt.eu>
Link: https://patch.msgid.link/20260404-nolibc-makedev-v2-4-456a429bf60c@weissschuh.net

show more ...

tools/nolibc: move the logic of makedev() and friends into functions

Functions make it easier to keep the input and output types straight and
avoid duplicate evaluations of their arguments.

Also th

tools/nolibc: move the logic of makedev() and friends into functions

Functions make it easier to keep the input and output types straight and
avoid duplicate evaluations of their arguments.

Also these functions will become a bit more complex to handle full
64-bit 'dev_t' which is easier to read in a function.

Still stay compatible with code which expects these to be macros.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Acked-by: Willy Tarreau <w@1wt.eu>
Link: https://patch.msgid.link/20260404-nolibc-makedev-v2-3-456a429bf60c@weissschuh.net

show more ...

tools/nolibc: explicitly list architecture headers

Relying on $(wildcard) is brittle and non-deterministic.

similar to all the other headers.
Switch the list of architecture headers to an explicit

tools/nolibc: explicitly list architecture headers

Relying on $(wildcard) is brittle and non-deterministic.

similar to all the other headers.
Switch the list of architecture headers to an explicit list,

Link: https://patch.msgid.link/20260401-nolibc-cleanup-v1-4-bcf4c9f5c1be@weissschuh.net
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>

show more ...

tools/nolibc: drop superfluous definition of Q

Q is already defined by tools/scripts/Makefile.include which is included
at the top of tools/include/nolibc/Makefile.

Signed-off-by: Thomas Weißschuh

tools/nolibc: drop superfluous definition of Q

Q is already defined by tools/scripts/Makefile.include which is included
at the top of tools/include/nolibc/Makefile.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Link: https://patch.msgid.link/20260401-nolibc-cleanup-v1-3-bcf4c9f5c1be@weissschuh.net

show more ...

tools/nolibc: drop superfluous invocation of mkdir

The call to 'mkdir -p $(OUTPUT)sysroot/include' will also create the
sysroot directory.

Drop the unnecessary explicit invocation of mkdir.

Signed

tools/nolibc: drop superfluous invocation of mkdir

The call to 'mkdir -p $(OUTPUT)sysroot/include' will also create the
sysroot directory.

Drop the unnecessary explicit invocation of mkdir.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Link: https://patch.msgid.link/20260401-nolibc-cleanup-v1-2-bcf4c9f5c1be@weissschuh.net

show more ...

tools/nolibc: drop superfluous invocation of 'make headers'

The headers_install target of the toplevel Makefile will already make
sure that the headers are up-to-date.

Drop the superfluous explicit

tools/nolibc: drop superfluous invocation of 'make headers'

The headers_install target of the toplevel Makefile will already make
sure that the headers are up-to-date.

Drop the superfluous explicit invocation.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Link: https://patch.msgid.link/20260401-nolibc-cleanup-v1-1-bcf4c9f5c1be@weissschuh.net

show more ...

tools/nolibc/printf: Support negative variable width and precision

For (eg) "%*.*s" treat a negative field width as a request to left align
the output (the same as the '-' flag), and a negative prec

tools/nolibc/printf: Support negative variable width and precision

For (eg) "%*.*s" treat a negative field width as a request to left align
the output (the same as the '-' flag), and a negative precision to
request the default precision.

Set the default precision to -1 (not INT_MAX) and add explicit checks
to the string handling for negative values (makes the tet unsigned).

For numeric output check for 'precision >= 0' instead of testing
_NOLIBC_PF_FLAGS_CONTAIN(flags, '.').
This needs an inverted test, some extra goto and removes an indentation.
The changed conditionals fix printf("%0-#o", 0) - but '0' and '-' shouldn't
both be specified.

Signed-off-by: David Laight <david.laight.linux@gmail.com>
Link: https://patch.msgid.link/20260323112247.3196-1-david.laight.linux@gmail.com
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>

show more ...

tools/nolibc: rename sys_foo() functions to _sys_foo()

The sys_foo() naming scheme used by the syscall wrappers may collide
with application symbols. Especially as 'sys_' is an obvious naming
scheme

tools/nolibc: rename sys_foo() functions to _sys_foo()

The sys_foo() naming scheme used by the syscall wrappers may collide
with application symbols. Especially as 'sys_' is an obvious naming
scheme an application may choose for its own custom systemcall wrappers.

Avoid these conflicts by using an leading underscore which moves the
names into the implementation's namespace. This naming scheme was chosen
over a '__nolibc_' prefix, as these functions are not an implementation
detail but a documented interface meant to be used by applications.

While this may break some existing users, adapting them should be
straightforward. Given that nolibc is most-likely vendored, no
unexpected breakage should happen. No in-tree users are affected.

These conflicts happen when compiling some of the kernel selftests
with nolibc.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Acked-by: Willy Tarreau <w@1wt.eu>
Link: https://patch.msgid.link/20260319-nolibc-namespacing-v1-1-33c22eaddb5e@weissschuh.net

show more ...

tools/nolibc: avoid -Wundef warning for __STDC_VERSION__

With -std=c89 the macro __STDC_VERSION__ is not defined.
While undefined identifiers in '#if' directives are assumed to be '0',
with -Wundef

tools/nolibc: avoid -Wundef warning for __STDC_VERSION__

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 <linux@weissschuh.net>
Acked-by: Willy Tarreau <w@1wt.eu>
Link: https://patch.msgid.link/20260318-nolibc-wundef-v1-1-fcb7f9ac7298@weissschuh.net

show more ...

tools/nolibc: add err.h

Add a few convenient helpers to print error and warning messages.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Acked-by: Willy Tarreau <w@1wt.eu>
Link: https://pat

tools/nolibc: add err.h

Add a few convenient helpers to print error and warning messages.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Acked-by: Willy Tarreau <w@1wt.eu>
Link: https://patch.msgid.link/20260318-nolibc-err-h-v4-2-08247a694bd9@weissschuh.net

show more ...

tools/nolibc: add support for program_invocation_{,short_}name

Add support for the GNU extensions 'program_invocation_name' and
'program_invocation_short_name'. These are useful to print error
messa

tools/nolibc: add support for program_invocation_{,short_}name

Add support for the GNU extensions 'program_invocation_name' and
'program_invocation_short_name'. These are useful to print error
messages, which by convention include the program name.

As these are global variables which take up memory even if not used,
similar to 'errno', gate them behind NOLIBC_IGNORE_ERRNO.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Acked-by: Willy Tarreau <w@1wt.eu>
Link: https://patch.msgid.link/20260318-nolibc-err-h-v4-1-08247a694bd9@weissschuh.net

show more ...

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

All MIPS ISAs before r6 use the 'lo' and 'hi' special registers.
These are clobbered by system calls and need to be mark

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

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 <macro@orcam.me.uk>
Link: https://lore.kernel.org/lkml/alpine.DEB.2.21.2603141744240.55200@angie.orcam.me.uk/
Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Link: https://patch.msgid.link/20260317-nolibc-mips-clobber-v2-1-5b9a97761a9e@linutronix.de
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>

show more ...

tools/nolibc/printf: Add support for octal output

Octal output isn't often used, but adding it costs very little.

Supporting "%#o" is mildly annoying, it has to add a leading '0' if
there isn't one

tools/nolibc/printf: Add support for octal output

Octal output isn't often used, but adding it costs very little.

Supporting "%#o" is mildly annoying, it has to add a leading '0' if
there isn't one present. In simple cases this is the same as adding a sign
of '0' - but that adds an extra '0' in a few places.
So you need 3 tests, %o, # and no leading '0' (which can only be checked
after the zero pad for precision).
If all the test are deferred until after zero padding then too many values
are 'live' across the call to _nolibc_u64toa_base() and get spilled to stack.
Hence the check that ignores the 'sign' if it is the same as the first
character of the output string.

Add tests for octal output.

Signed-off-by: David Laight <david.laight.linux@gmail.com>
Acked-by: Willy Tarreau <w@1wt.eu>
Link: https://patch.msgid.link/20260308113742.12649-17-david.laight.linux@gmail.com
[Thomas: avoid a -Wsign-compare]
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>

show more ...

tools/nolibc/printf: Add support for zero padding and field precision

Includes support for variable field widths (eg "%*.*d").

Zero padding is limited to 31 zero characters.
This is wider than the

tools/nolibc/printf: Add support for zero padding and field precision

Includes support for variable field widths (eg "%*.*d").

Zero padding is limited to 31 zero characters.
This is wider than the largest numeric field so shouldn't be a problem.

All the standard printf formats are now supported except octal
and floating point.

Add tests for new features

Signed-off-by: David Laight <david.laight.linux@gmail.com>
Acked-by: Willy Tarreau <w@1wt.eu>
Link: https://patch.msgid.link/20260308113742.12649-16-david.laight.linux@gmail.com
[Thomas: fixup testcases for musl libc]
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>

show more ...