diff options
| author | Daniel Palmer <daniel@thingy.jp> | 2026-05-21 20:31:03 +0300 |
|---|---|---|
| committer | Thomas Weißschuh <linux@weissschuh.net> | 2026-05-25 00:57:59 +0300 |
| commit | acbbec15195b40adefd24993661c93022f6de2b7 (patch) | |
| tree | ee45624c24405e4de72c3c1a23b37b2f06405303 | |
| parent | f66d6bc35e45dfd71c95f3f4e0407081db2c0c35 (diff) | |
| download | linux-acbbec15195b40adefd24993661c93022f6de2b7.tar.xz | |
tools/nolibc: add a helper to split a 64-bit argument into 32-bit halves
On 32-bit architectures some system calls require a single 64-bit
argument to be passed as two 32-bit halves.
Add a helper to easily split such arguments. This works on little and
bit endian.
Signed-off-by: Daniel Palmer <daniel@thingy.jp>
Acked-by: Willy Tarreau <w@1wt.eu>
Link: https://patch.msgid.link/20260521-nolibc-ftruncate-v1-2-5384a83b2402@weissschuh.net
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
| -rw-r--r-- | tools/include/nolibc/sys.h | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/tools/include/nolibc/sys.h b/tools/include/nolibc/sys.h index 33f9c970ae57..548f94d96ed2 100644 --- a/tools/include/nolibc/sys.h +++ b/tools/include/nolibc/sys.h @@ -70,6 +70,17 @@ static __inline__ int __nolibc_enosys(const char *syscall, ...) } #endif + +/* + * Helper for 32-bit machines where a 64-bit syscall arg needs to be split into + * two 32-bit parts while making sure the order of the low/high parts are correct + * for the endianness: + * __NOLIBC_LLARGPART(x, 0), __NOLIBC_LLARGPART(x, 1) + */ +#define __NOLIBC_LLARGPART(_arg, _part) \ + (((union { long long ll; long l[2]; }) { .ll = _arg }).l[_part]) + + /* Functions in this file only describe syscalls. They're declared static so * that the compiler usually decides to inline them while still being allowed * to pass a pointer to one of their instances. Each syscall exists in two |