1 files changed, 42 insertions, 0 deletions

diff --git a/gl/sys-limits.h b/gl/sys-limits.h
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+++ b/gl/sys-limits.h
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+/* System call limits
+
+   Copyright 2018-2022 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