/* System call limits Copyright 2018-2023 Free Software Foundation, Inc. This file is free software: you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2.1 of the License, or (at your option) any later version. This file is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details. You should have received a copy of the GNU Lesser General Public License along with this program. If not, see <https://www.gnu.org/licenses/>. */ #ifndef _GL_SYS_LIMITS_H #define _GL_SYS_LIMITS_H #include <limits.h> /* Maximum number of bytes to read or write in a single system call. This can be useful for system calls like sendfile on GNU/Linux, which do not handle more than MAX_RW_COUNT bytes correctly. The Linux kernel MAX_RW_COUNT is at least INT_MAX >> 20 << 20, where the 20 comes from the Hexagon port with 1 MiB pages; use that as an approximation, as the exact value may not be available to us. Using this also works around a serious Linux bug before 2.6.16; see <https://bugzilla.redhat.com/show_bug.cgi?id=612839>. Using this also works around a Tru64 5.1 bug, where attempting to read INT_MAX bytes fails with errno == EINVAL. See <https://lists.gnu.org/r/bug-gnu-utils/2002-04/msg00010.html>. Using this is likely to work around similar bugs in other operating systems. */ enum { SYS_BUFSIZE_MAX = INT_MAX >> 20 << 20 }; #endif