cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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fd.c (1934B)

      1// SPDX-License-Identifier: GPL-2.0
      2/*
      3 * Copyright (C) 2001 - 2007 Jeff Dike (jdike@{linux.intel,addtoit}.com)
      4 */
      5
      6#include <stdio.h>
      7#include <stdlib.h>
      8#include <unistd.h>
      9#include <errno.h>
     10#include <termios.h>
     11#include "chan_user.h"
     12#include <os.h>
     13#include <um_malloc.h>
     14
     15struct fd_chan {
     16	int fd;
     17	int raw;
     18	struct termios tt;
     19	char str[sizeof("1234567890\0")];
     20};
     21
     22static void *fd_init(char *str, int device, const struct chan_opts *opts)
     23{
     24	struct fd_chan *data;
     25	char *end;
     26	int n;
     27
     28	if (*str != ':') {
     29		printk(UM_KERN_ERR "fd_init : channel type 'fd' must specify a "
     30		       "file descriptor\n");
     31		return NULL;
     32	}
     33	str++;
     34	n = strtoul(str, &end, 0);
     35	if ((*end != '\0') || (end == str)) {
     36		printk(UM_KERN_ERR "fd_init : couldn't parse file descriptor "
     37		       "'%s'\n", str);
     38		return NULL;
     39	}
     40
     41	data = uml_kmalloc(sizeof(*data), UM_GFP_KERNEL);
     42	if (data == NULL)
     43		return NULL;
     44
     45	*data = ((struct fd_chan) { .fd  	= n,
     46				    .raw  	= opts->raw });
     47	return data;
     48}
     49
     50static int fd_open(int input, int output, int primary, void *d, char **dev_out)
     51{
     52	struct fd_chan *data = d;
     53	int err;
     54
     55	if (data->raw && isatty(data->fd)) {
     56		CATCH_EINTR(err = tcgetattr(data->fd, &data->tt));
     57		if (err)
     58			return err;
     59
     60		err = raw(data->fd);
     61		if (err)
     62			return err;
     63	}
     64	sprintf(data->str, "%d", data->fd);
     65	*dev_out = data->str;
     66	return data->fd;
     67}
     68
     69static void fd_close(int fd, void *d)
     70{
     71	struct fd_chan *data = d;
     72	int err;
     73
     74	if (!data->raw || !isatty(fd))
     75		return;
     76
     77	CATCH_EINTR(err = tcsetattr(fd, TCSAFLUSH, &data->tt));
     78	if (err)
     79		printk(UM_KERN_ERR "Failed to restore terminal state - "
     80		       "errno = %d\n", -err);
     81	data->raw = 0;
     82}
     83
     84const struct chan_ops fd_ops = {
     85	.type		= "fd",
     86	.init		= fd_init,
     87	.open		= fd_open,
     88	.close		= fd_close,
     89	.read		= generic_read,
     90	.write		= generic_write,
     91	.console_write	= generic_console_write,
     92	.window_size	= generic_window_size,
     93	.free		= generic_free,
     94	.winch		= 1,
     95};