linux-stable.git/tools/include/nolibc, branch linux-5.15.y

tools/nolibc: make time_t robust if __kernel_old_time_t is missing in host headers

2025-10-19T14:21:31+00:00

[ Upstream commit 0ff52df6b32a6b04a7c9dfe3d7a387aff215b482 ]

Commit d5094bcb5bfd ("tools/nolibc: define time_t in terms of
__kernel_old_time_t") made nolibc use the kernel's time type so that
`time_t` matches `timespec::tv_sec` on all ABIs (notably x32).

But since __kernel_old_time_t is fairly new, notably from 2020 in commit
94c467ddb273 ("y2038: add __kernel_old_timespec and __kernel_old_time_t"),
nolibc builds that rely on host headers may fail.

Switch to __kernel_time_t, which is the same as __kernel_old_time_t and
has existed for longer.

Tested in PPC VM of Open Source Lab of Oregon State University
(./tools/testing/selftests/rcutorture/bin/mkinitrd.sh)

Fixes: d5094bcb5bfd ("tools/nolibc: define time_t in terms of __kernel_old_time_t")
Signed-off-by: Zhouyi Zhou 
[Thomas: Reformat commit and its message a bit]
Signed-off-by: Thomas Weißschuh 
Signed-off-by: Sasha Levin

tools/nolibc: define time_t in terms of __kernel_old_time_t

2025-08-28T14:24:18+00:00

[ Upstream commit d5094bcb5bfdfea2cf0de8aaf77cc65db56cbdb5 ]

Nolibc assumes that the kernel ABI is using a time values that are as
large as a long integer. For most ABIs this holds true.
But for x32 this is not correct, as it uses 32bit longs but 64bit times.

Also the 'struct stat' implementation of nolibc relies on timespec::tv_sec
and time_t being the same type. While timespec::tv_sec comes from the
kernel and is of type __kernel_old_time_t, time_t is defined within nolibc.

Switch to the __kernel_old_time_t to always get the correct type.

Signed-off-by: Thomas Weißschuh 
Link: https://lore.kernel.org/r/20250712-nolibc-x32-v1-1-6d81cb798710@weissschuh.net
Acked-by: Willy Tarreau 
Signed-off-by: Sasha Levin

tools/nolibc: fix the O_* fcntl/open macro definitions for riscv

2023-01-18T10:48:56+00:00

[ Upstream commit 00b18da4089330196906b9fe075c581c17eb726c ]

When RISCV port was imported in 5.2, the O_* macros were taken with
their octal value and written as-is in hex, resulting in the getdents64()
to fail in nolibc-test.

Fixes: 582e84f7b779 ("tool headers nolibc: add RISCV support") #5.2
Signed-off-by: Willy Tarreau 
Signed-off-by: Paul E. McKenney 
Signed-off-by: Sasha Levin

tools/nolibc: restore mips branch ordering in the _start block

2023-01-18T10:48:56+00:00

[ Upstream commit 184177c3d6e023da934761e198c281344d7dd65b ]

Depending on the compiler used and the optimization options, the sbrk()
test was crashing, both on real hardware (mips-24kc) and in qemu. One
such example is kernel.org toolchain in version 11.3 optimizing at -Os.

Inspecting the sys_brk() call shows the following code:

  0040047c :
    40047c:       24020fcd        li      v0,4045
    400480:       27bdffe0        addiu   sp,sp,-32
    400484:       0000000c        syscall
    400488:       27bd0020        addiu   sp,sp,32
    40048c:       10e00001        beqz    a3,400494 
    400490:       00021023        negu    v0,v0
    400494:       03e00008        jr      ra

It is obviously wrong, the "negu" instruction is placed in beqz's
delayed slot, and worse, there's no nop nor instruction after the
return, so the next function's first instruction (addiu sip,sip,-32)
will also be executed as part of the delayed slot that follows the
return.

This is caused by the ".set noreorder" directive in the _start block,
that applies to the whole program. The compiler emits code without the
delayed slots and relies on the compiler to swap instructions when this
option is not set. Removing the option would require to change the
startup code in a way that wouldn't make it look like the resulting
code, which would not be easy to debug. Instead let's just save the
default ordering before changing it, and restore it at the end of the
_start block. Now the code is correct:

  0040047c :
    40047c:       24020fcd        li      v0,4045
    400480:       27bdffe0        addiu   sp,sp,-32
    400484:       0000000c        syscall
    400488:       10e00002        beqz    a3,400494 
    40048c:       27bd0020        addiu   sp,sp,32
    400490:       00021023        negu    v0,v0
    400494:       03e00008        jr      ra
    400498:       00000000        nop

Fixes: 66b6f755ad45 ("rcutorture: Import a copy of nolibc") #5.0
Signed-off-by: Willy Tarreau 
Signed-off-by: Paul E. McKenney 
Signed-off-by: Sasha Levin

tools/nolibc: Remove .global _start from the entry point code

2023-01-18T10:48:56+00:00

[ Upstream commit 1590c59836dace3a20945bad049fe8802c4e6f3f ]

Building with clang yields the following error:
```
  :3:1: error: _start changed binding to STB_GLOBAL
  .global _start
  ^
  1 error generated.
```
Make sure only specify one between `.global _start` and `.weak _start`.
Remove `.global _start`.

Cc: llvm@lists.linux.dev
Reviewed-by: Nick Desaulniers 
Acked-by: Willy Tarreau 
Signed-off-by: Ammar Faizi 
Signed-off-by: Paul E. McKenney 
Stable-dep-of: 184177c3d6e0 ("tools/nolibc: restore mips branch ordering in the _start block")
Signed-off-by: Sasha Levin

tools/nolibc/arch: mark the _start symbol as weak

2023-01-18T10:48:55+00:00

[ Upstream commit dffeb81af5fe5eedccf5ea4a8a120d8c3accd26e ]

By doing so we can link together multiple C files that have been compiled
with nolibc and which each have a _start symbol.

Signed-off-by: Willy Tarreau 
Signed-off-by: Paul E. McKenney 
Stable-dep-of: 184177c3d6e0 ("tools/nolibc: restore mips branch ordering in the _start block")
Signed-off-by: Sasha Levin

tools/nolibc/arch: split arch-specific code into individual files

2023-01-18T10:48:55+00:00

[ Upstream commit 271661c1cde5ff47eb7af9946866cd66b70dc328 ]

In order to ease maintenance, this splits the arch-specific code into
one file per architecture. A common file "arch.h" is used to include the
right file among arch-* based on the detected architecture. Projects
which are already split per architecture could simply rename these
files to $arch/arch.h and get rid of the common arch.h. For this
reason, include guards were placed into each arch-specific file.

Signed-off-by: Willy Tarreau 
Signed-off-by: Paul E. McKenney 
Stable-dep-of: 184177c3d6e0 ("tools/nolibc: restore mips branch ordering in the _start block")
Signed-off-by: Sasha Levin

tools/nolibc/types: split syscall-specific definitions into their own files

2023-01-18T10:48:55+00:00

[ Upstream commit cc7a492ad0a076dff5cb4281b1516676d7924fcf ]

The macros and type definitions used by a number of syscalls were moved
to types.h where they will be easier to maintain. A few of them
are arch-specific and must not be moved there (e.g. O_*, sys_stat_struct).
A warning about them was placed at the top of the file.

Signed-off-by: Willy Tarreau 
Signed-off-by: Paul E. McKenney 
Stable-dep-of: 184177c3d6e0 ("tools/nolibc: restore mips branch ordering in the _start block")
Signed-off-by: Sasha Levin

tools/nolibc/std: move the standard type definitions to std.h

2023-01-18T10:48:55+00:00

[ Upstream commit 967cce191f50090d5cbd3841ee2bbb7835afeae2 ]

The ordering of includes and definitions for now is a bit of a mess, as
for example asm/signal.h is included after int definitions, but plenty of
structures are defined later as they rely on other includes.

Let's move the standard type definitions to a dedicated file that is
included first. We also move NULL there. This way all other includes
are aware of it, and we can bring asm/signal.h back to the top of the
file.

Signed-off-by: Willy Tarreau 
Signed-off-by: Paul E. McKenney 
Stable-dep-of: 184177c3d6e0 ("tools/nolibc: restore mips branch ordering in the _start block")
Signed-off-by: Sasha Levin

tools/nolibc: use pselect6 on RISCV

2023-01-18T10:48:55+00:00

[ Upstream commit 9c2970fbb425cca0256ecf0f96490e4f253fda24 ]

This arch doesn't provide the old-style select() syscall, we have to
use pselect6().

Signed-off-by: Willy Tarreau 
Signed-off-by: Paul E. McKenney 
Stable-dep-of: 184177c3d6e0 ("tools/nolibc: restore mips branch ordering in the _start block")
Signed-off-by: Sasha Levin