From: Daniel Palmer Date: Thu, 21 May 2026 17:31:03 +0000 (+0200) Subject: tools/nolibc: add a helper to split a 64-bit argument into 32-bit halves X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=acbbec15195b40adefd24993661c93022f6de2b7;p=thirdparty%2Flinux.git 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 Acked-by: Willy Tarreau Link: https://patch.msgid.link/20260521-nolibc-ftruncate-v1-2-5384a83b2402@weissschuh.net Signed-off-by: Thomas Weißschuh --- diff --git a/tools/include/nolibc/sys.h b/tools/include/nolibc/sys.h index 33f9c970ae576..548f94d96ed20 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