cachepc-qemu

Fork of AMDESE/qemu with changes for cachepc side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-qemu
Log | Files | Refs | Submodules | LICENSE | sfeed.txt

semihost.c (2236B)

      1/*
      2 * ARM Compatible Semihosting Console Support.
      3 *
      4 * Copyright (c) 2019 Linaro Ltd
      5 *
      6 * Currently ARM and RISC-V are unique in having support for
      7 * semihosting support in linux-user. So for now we implement the
      8 * common console API but just for arm and risc-v linux-user.
      9 *
     10 * SPDX-License-Identifier: GPL-2.0-or-later
     11 */
     12
     13#include "qemu/osdep.h"
     14#include "semihosting/console.h"
     15#include "qemu.h"
     16#include "user-internals.h"
     17#include <termios.h>
     18
     19int qemu_semihosting_console_outs(CPUArchState *env, target_ulong addr)
     20{
     21    int len = target_strlen(addr);
     22    void *s;
     23    if (len < 0){
     24       qemu_log_mask(LOG_GUEST_ERROR,
     25                     "%s: passed inaccessible address " TARGET_FMT_lx,
     26                     __func__, addr);
     27       return 0;
     28    }
     29    s = lock_user(VERIFY_READ, addr, (long)(len + 1), 1);
     30    g_assert(s);  /* target_strlen has already verified this will work */
     31    len = write(STDERR_FILENO, s, len);
     32    unlock_user(s, addr, 0);
     33    return len;
     34}
     35
     36void qemu_semihosting_console_outc(CPUArchState *env, target_ulong addr)
     37{
     38    char c;
     39
     40    if (get_user_u8(c, addr)) {
     41        qemu_log_mask(LOG_GUEST_ERROR,
     42                      "%s: passed inaccessible address " TARGET_FMT_lx,
     43                      __func__, addr);
     44    } else {
     45        if (write(STDERR_FILENO, &c, 1) != 1) {
     46            qemu_log_mask(LOG_UNIMP, "%s: unexpected write to stdout failure",
     47                          __func__);
     48        }
     49    }
     50}
     51
     52/*
     53 * For linux-user we can safely block. However as we want to return as
     54 * soon as a character is read we need to tweak the termio to disable
     55 * line buffering. We restore the old mode afterwards in case the
     56 * program is expecting more normal behaviour. This is slow but
     57 * nothing using semihosting console reading is expecting to be fast.
     58 */
     59target_ulong qemu_semihosting_console_inc(CPUArchState *env)
     60{
     61    uint8_t c;
     62    struct termios old_tio, new_tio;
     63
     64    /* Disable line-buffering and echo */
     65    tcgetattr(STDIN_FILENO, &old_tio);
     66    new_tio = old_tio;
     67    new_tio.c_lflag &= (~ICANON & ~ECHO);
     68    tcsetattr(STDIN_FILENO, TCSANOW, &new_tio);
     69
     70    c = getchar();
     71
     72    /* restore config */
     73    tcsetattr(STDIN_FILENO, TCSANOW, &old_tio);
     74
     75    return (target_ulong) c;
     76}