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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harddog_user.c (2479B)

      1// SPDX-License-Identifier: GPL-2.0
      2/*
      3 * Copyright (C) 2002 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
      4 */
      5
      6#include <stdio.h>
      7#include <unistd.h>
      8#include <errno.h>
      9#include <os.h>
     10
     11struct dog_data {
     12	int stdin_fd;
     13	int stdout_fd;
     14	int close_me[2];
     15};
     16
     17static void pre_exec(void *d)
     18{
     19	struct dog_data *data = d;
     20
     21	dup2(data->stdin_fd, 0);
     22	dup2(data->stdout_fd, 1);
     23	dup2(data->stdout_fd, 2);
     24	close(data->stdin_fd);
     25	close(data->stdout_fd);
     26	close(data->close_me[0]);
     27	close(data->close_me[1]);
     28}
     29
     30int start_watchdog(int *in_fd_ret, int *out_fd_ret, char *sock)
     31{
     32	struct dog_data data;
     33	int in_fds[2], out_fds[2], pid, n, err;
     34	char pid_buf[sizeof("nnnnnnn\0")], c;
     35	char *pid_args[] = { "/usr/bin/uml_watchdog", "-pid", pid_buf, NULL };
     36	char *mconsole_args[] = { "/usr/bin/uml_watchdog", "-mconsole", NULL,
     37				  NULL };
     38	char **args = NULL;
     39
     40	err = os_pipe(in_fds, 1, 0);
     41	if (err < 0) {
     42		printk("harddog_open - os_pipe failed, err = %d\n", -err);
     43		goto out;
     44	}
     45
     46	err = os_pipe(out_fds, 1, 0);
     47	if (err < 0) {
     48		printk("harddog_open - os_pipe failed, err = %d\n", -err);
     49		goto out_close_in;
     50	}
     51
     52	data.stdin_fd = out_fds[0];
     53	data.stdout_fd = in_fds[1];
     54	data.close_me[0] = out_fds[1];
     55	data.close_me[1] = in_fds[0];
     56
     57	if (sock != NULL) {
     58		mconsole_args[2] = sock;
     59		args = mconsole_args;
     60	}
     61	else {
     62		/* XXX The os_getpid() is not SMP correct */
     63		sprintf(pid_buf, "%d", os_getpid());
     64		args = pid_args;
     65	}
     66
     67	pid = run_helper(pre_exec, &data, args);
     68
     69	close(out_fds[0]);
     70	close(in_fds[1]);
     71
     72	if (pid < 0) {
     73		err = -pid;
     74		printk("harddog_open - run_helper failed, errno = %d\n", -err);
     75		goto out_close_out;
     76	}
     77
     78	n = read(in_fds[0], &c, sizeof(c));
     79	if (n == 0) {
     80		printk("harddog_open - EOF on watchdog pipe\n");
     81		helper_wait(pid);
     82		err = -EIO;
     83		goto out_close_out;
     84	}
     85	else if (n < 0) {
     86		printk("harddog_open - read of watchdog pipe failed, "
     87		       "err = %d\n", errno);
     88		helper_wait(pid);
     89		err = n;
     90		goto out_close_out;
     91	}
     92	*in_fd_ret = in_fds[0];
     93	*out_fd_ret = out_fds[1];
     94	return 0;
     95
     96 out_close_in:
     97	close(in_fds[0]);
     98	close(in_fds[1]);
     99 out_close_out:
    100	close(out_fds[0]);
    101	close(out_fds[1]);
    102 out:
    103	return err;
    104}
    105
    106void stop_watchdog(int in_fd, int out_fd)
    107{
    108	close(in_fd);
    109	close(out_fd);
    110}
    111
    112int ping_watchdog(int fd)
    113{
    114	int n;
    115	char c = '\n';
    116
    117	n = write(fd, &c, sizeof(c));
    118	if (n != sizeof(c)) {
    119		printk("ping_watchdog - write failed, ret = %d, err = %d\n",
    120		       n, errno);
    121		if (n < 0)
    122			return n;
    123		return -EIO;
    124	}
    125	return 1;
    126
    127}