linux-toradex.git/tools/include/nolibc, branch v6.9-rc4

tools/nolibc: add support for getrlimit/setrlimit

2023-12-11T21:38:35+00:00

The implementation uses the prlimit64 systemcall as that is available on
all architectures.

Signed-off-by: Thomas Weißschuh 
Link: https://lore.kernel.org/lkml/20231123-nolibc-rlimit-v1-2-a428b131de2a@weissschuh.net/
Acked-by: Willy Tarreau

tools/nolibc: drop custom definition of struct rusage

2023-12-11T21:38:34+00:00

A future commit will include linux/resource.h, which will conflict with
the private definition of struct rusage in nolibc.
Avoid the conflict by dropping the private definition and use the one
from the UAPI headers.

Signed-off-by: Thomas Weißschuh 
Link: https://lore.kernel.org/lkml/20231123-nolibc-rlimit-v1-1-a428b131de2a@weissschuh.net/
Acked-by: Willy Tarreau

tools/nolibc: annotate va_list printf formats

2023-12-11T21:38:32+00:00

__attribute__(format(printf)) can also be used for functions that take a
va_list argument.

As per the GCC docs:

    For functions where the arguments are not available to be checked
    (such as vprintf), specify the third parameter as zero.

Link: https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html
Signed-off-by: Thomas Weißschuh

tools/nolibc: mips: add support for PIC

2023-12-11T21:38:30+00:00

MIPS requires some extra instructions to set up the $gp register for the
with a pointer to the global data area.

This isn't needed for non-PIC builds, but this patch enables the code
unconditionally to prevent bitrot.

Also enable PIC in one of the test configurations for ongoing
validation.

Link: https://lore.kernel.org/r/20231108-nolibc-pic-v2-1-4fb0d6284757@weissschuh.net
Signed-off-by: Thomas Weißschuh

tools/nolibc: move MIPS ABI validation into arch-mips.h

2023-12-11T21:38:21+00:00

When installing nolibc to a sysroot arch.h is not used so its ABI check
is bypassed. This makes is possible to compile nolibc with a non O32 ABI
which may build but can not run.

Move the check into arch-mips.h so it will always be evaluated.

Signed-off-by: Thomas Weißschuh 
Acked-by: Willy Tarreau

tools/nolibc: error out on unsupported architecture

2023-12-11T21:38:20+00:00

When an architecture is unsupported arch.h would silently continue.
This leads to a lot of followup errors because my_syscallX() is not
defined and the startup code is missing.

Avoid these confusing errors and fail the build early with a clear
error message and location.

Signed-off-by: Thomas Weißschuh 
Acked-by: Willy Tarreau

tools/nolibc: Use linux/wait.h rather than duplicating it

2023-12-11T21:38:08+00:00

Linux defines a few custom flags for waitpid() which aren't currently
provided by nolibc, make them available to nolibc based programs by just
including linux/wait.h where they are defined instead of defining our
own copy of the flags.

Signed-off-by: Mark Brown 
Signed-off-by: Willy Tarreau 
Signed-off-by: Thomas Weißschuh

tools/nolibc: add support for constructors and destructors

2023-10-12T19:14:16+00:00

With the startup code moved to C, implementing support for
constructors and deconstructors is fairly easy to implement.

Examples for code size impact:

   text	   data	    bss	    dec	    hex	filename
  21837	    104	     88	  22029	   560d	nolibc-test.before
  22135	    120	     88	  22343	   5747	nolibc-test.after
  21970	    104	     88	  22162	   5692 nolibc-test.after-only-crt.h-changes

The sections are defined by [0].

[0] https://refspecs.linuxfoundation.org/elf/gabi4+/ch5.dynamic.html

Signed-off-by: Thomas Weißschuh 
Acked-by: Willy Tarreau 
Link: https://lore.kernel.org/lkml/20231007-nolibc-constructors-v2-1-ef84693efbc1@weissschuh.net/

tools/nolibc: automatically detect necessity to use pselect6

2023-10-12T19:14:13+00:00

We can automatically detect if pselect6 is needed or not from the kernel
headers. This removes the need to manually specify it.

Signed-off-by: Thomas Weißschuh 
Acked-by: Willy Tarreau 
Link: https://lore.kernel.org/r/20230917-nolibc-syscall-nr-v2-4-03863d509b9a@weissschuh.net

tools/nolibc: don't define new syscall number

2023-10-12T19:14:12+00:00

All symbols created by nolibc are also visible to user code.
Syscall constants are expected to come from the kernel headers and
should not be made up by nolibc.

Refactor the logic to avoid defining syscall numbers.
Also the new code is easier to understand.

Signed-off-by: Thomas Weißschuh 
Acked-by: Willy Tarreau 
Link: https://lore.kernel.org/r/20230917-nolibc-syscall-nr-v2-3-03863d509b9a@weissschuh.net