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62d6c33030
When casting between a pointer and an integer of a different size, GCC emits a warning (which is escalated to a build failure by -Werror). Indeed, if what you start with is a pointer, which you then cast to a shorter integer and then back again, you're going to cut off some bits of the pointer. But if you start with an integer (such as mach_port_t), then cast it to a longer pointer (void *), and then back to a shorter integer, you are fine. To keep GCC happy, cast through an intermediary uintptr_t, which is always the same size as a pointer. Signed-off-by: Sergey Bugaev <bugaevc@gmail.com> Message-Id: <20230212111044.610942-4-bugaevc@gmail.com>
138 lines
3.4 KiB
C
138 lines
3.4 KiB
C
/* Copyright (C) 1994-2023 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, see
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<https://www.gnu.org/licenses/>. */
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#include <hurd.h>
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#include <stdio.h>
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#include <fcntl.h>
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#include <string.h>
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/* Read up to N chars into BUF from COOKIE.
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Return how many chars were read, 0 for EOF or -1 for error. */
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static ssize_t
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readio (void *cookie, char *buf, size_t n)
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{
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mach_msg_type_number_t nread;
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error_t err;
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char *bufp = buf;
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io_t io = (io_t) (uintptr_t) cookie;
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nread = n;
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if (err = __io_read (io, &bufp, &nread, -1, n))
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return __hurd_fail (err);
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if (bufp != buf)
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{
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memcpy (buf, bufp, nread);
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__vm_deallocate (__mach_task_self (),
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(vm_address_t) bufp, (vm_size_t) nread);
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}
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return nread;
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}
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/* Write up to N chars from BUF to COOKIE.
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Return how many chars were written or -1 for error. */
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static ssize_t
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writeio (void *cookie, const char *buf, size_t n)
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{
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vm_size_t wrote;
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error_t err;
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io_t io = (io_t) (uintptr_t) cookie;
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if (err = __io_write (io, buf, n, -1, &wrote))
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return __hurd_fail (err);
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return wrote;
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}
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/* Move COOKIE's file position *POS bytes, according to WHENCE.
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The current file position is stored in *POS.
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Returns zero if successful, nonzero if not. */
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static int
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seekio (void *cookie,
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off64_t *pos,
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int whence)
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{
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io_t io = (io_t) (uintptr_t) cookie;
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error_t err = __io_seek (io, *pos, whence, pos);
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return err ? __hurd_fail (err) : 0;
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}
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/* Close the file associated with COOKIE.
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Return 0 for success or -1 for failure. */
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static int
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closeio (void *cookie)
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{
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io_t io = (io_t) (uintptr_t) cookie;
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error_t error = __mach_port_deallocate (__mach_task_self (),
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io);
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if (error)
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return __hurd_fail (error);
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return 0;
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}
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#include "../libio/libioP.h"
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#define fopencookie _IO_fopencookie
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static const cookie_io_functions_t funcsio =
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{ readio, writeio, seekio, closeio };
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/* Open a stream on PORT. MODE is as for fopen. */
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FILE *
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__fopenport (mach_port_t port, const char *mode)
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{
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int pflags;
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int needflags;
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error_t err;
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const char *m = mode;
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switch (*m++)
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{
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case 'r':
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needflags = O_READ;
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break;
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case 'w':
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needflags = O_WRITE;
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break;
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case 'a':
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needflags = O_WRITE|O_APPEND;
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break;
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default:
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return NULL;
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}
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if (m[0] == '+' || (m[0] == 'b' && m[1] == '+'))
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needflags |= O_RDWR;
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/* Verify the PORT is valid allows the access MODE specifies. */
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if (err = __io_get_openmodes (port, &pflags))
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return __hurd_fail (err), NULL;
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/* Check the access mode. */
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if ((pflags & needflags) != needflags)
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{
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errno = EBADF;
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return NULL;
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}
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return fopencookie ((void *) (uintptr_t) port,
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mode, funcsio);
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}
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weak_alias (__fopenport, fopenport)
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