bsd-user/freebsd/os-syscall.c - qemu - Git at Google

 /*
  *  BSD syscalls
  *
  *  Copyright (c) 2003-2008 Fabrice Bellard
  *  Copyright (c) 2013-2014 Stacey D. Son
  *
  *  This program is free software; you can redistribute it and/or modify
  *  it under the terms of the GNU General Public License as published by
  *  the Free Software Foundation; either version 2 of the License, or
  *  (at your option) any later version.
  *
  *  This program 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 General Public License for more details.
  *
  *  You should have received a copy of the GNU General Public License
  *  along with this program; if not, see <http://www.gnu.org/licenses/>.
  */

 /*
  * We need the FreeBSD "legacy" definitions. Rust needs the FreeBSD 11 system
  * calls since it doesn't use libc at all, so we have to emulate that despite
  * FreeBSD 11 being EOL'd.
  */
 #define _WANT_FREEBSD11_STAT
 #define _WANT_FREEBSD11_STATFS
 #define _WANT_FREEBSD11_DIRENT
 #define _WANT_KERNEL_ERRNO
 #define _WANT_SEMUN
 #include "qemu/osdep.h"
 #include "qemu/cutils.h"
 #include "qemu/path.h"
 #include <sys/syscall.h>
 #include <sys/param.h>
 #include <sys/sysctl.h>
 #include <utime.h>

 #include "qemu.h"
 #include "signal-common.h"
 #include "user/syscall-trace.h"

 #include "bsd-file.h"
 #include "bsd-proc.h"

 /* I/O */
 safe_syscall3(ssize_t, read, int, fd, void *, buf, size_t, nbytes);
 safe_syscall4(ssize_t, pread, int, fd, void *, buf, size_t, nbytes, off_t,
     offset);
 safe_syscall3(ssize_t, readv, int, fd, const struct iovec *, iov, int, iovcnt);
 safe_syscall4(ssize_t, preadv, int, fd, const struct iovec *, iov, int, iovcnt,
     off_t, offset);

 safe_syscall3(ssize_t, write, int, fd, void *, buf, size_t, nbytes);
 safe_syscall4(ssize_t, pwrite, int, fd, void *, buf, size_t, nbytes, off_t,
     offset);
 safe_syscall3(ssize_t, writev, int, fd, const struct iovec *, iov, int, iovcnt);
 safe_syscall4(ssize_t, pwritev, int, fd, const struct iovec *, iov, int, iovcnt,
     off_t, offset);

 void target_set_brk(abi_ulong new_brk)
 {
 }

 /*
  * errno conversion.
  */
 abi_long get_errno(abi_long ret)
 {
     if (ret == -1) {
         return -host_to_target_errno(errno);
     } else {
         return ret;
     }
 }

 int host_to_target_errno(int err)
 {
     /*
      * All the BSDs have the property that the error numbers are uniform across
      * all architectures for a given BSD, though they may vary between different
      * BSDs.
      */
     return err;
 }

 bool is_error(abi_long ret)
 {
     return (abi_ulong)ret >= (abi_ulong)(-4096);
 }

 /*
  * Unlocks a iovec. Unlike unlock_iovec, it assumes the tvec array itself is
  * already locked from target_addr. It will be unlocked as well as all the iovec
  * elements.
  */
 static void helper_unlock_iovec(struct target_iovec *target_vec,
                                 abi_ulong target_addr, struct iovec *vec,
                                 int count, int copy)
 {
     for (int i = 0; i < count; i++) {
         abi_ulong base = tswapal(target_vec[i].iov_base);

         if (vec[i].iov_base) {
             unlock_user(vec[i].iov_base, base, copy ? vec[i].iov_len : 0);
         }
     }
     unlock_user(target_vec, target_addr, 0);
 }

 struct iovec *lock_iovec(int type, abi_ulong target_addr,
         int count, int copy)
 {
     struct target_iovec *target_vec;
     struct iovec *vec;
     abi_ulong total_len, max_len;
     int i;
     int err = 0;

     if (count == 0) {
         errno = 0;
         return NULL;
     }
     if (count < 0 || count > IOV_MAX) {
         errno = EINVAL;
         return NULL;
     }

     vec = g_try_new0(struct iovec, count);
     if (vec == NULL) {
         errno = ENOMEM;
         return NULL;
     }

     target_vec = lock_user(VERIFY_READ, target_addr,
                            count * sizeof(struct target_iovec), 1);
     if (target_vec == NULL) {
         err = EFAULT;
         goto fail2;
     }

     max_len = 0x7fffffff & MIN(TARGET_PAGE_MASK, PAGE_MASK);
     total_len = 0;

     for (i = 0; i < count; i++) {
         abi_ulong base = tswapal(target_vec[i].iov_base);
         abi_long len = tswapal(target_vec[i].iov_len);

         if (len < 0) {
             err = EINVAL;
             goto fail;
         } else if (len == 0) {
             /* Zero length pointer is ignored. */
             vec[i].iov_base = 0;
         } else {
             vec[i].iov_base = lock_user(type, base, len, copy);
             /*
              * If the first buffer pointer is bad, this is a fault.  But
              * subsequent bad buffers will result in a partial write; this is
              * realized by filling the vector with null pointers and zero
              * lengths.
              */
             if (!vec[i].iov_base) {
                 if (i == 0) {
                     err = EFAULT;
                     goto fail;
                 } else {
                     /*
                      * Fail all the subsequent addresses, they are already
                      * zero'd.
                      */
                     goto out;
                 }
             }
             if (len > max_len - total_len) {
                 len = max_len - total_len;
             }
         }
         vec[i].iov_len = len;
         total_len += len;
     }
 out:
     unlock_user(target_vec, target_addr, 0);
     return vec;

 fail:
     helper_unlock_iovec(target_vec, target_addr, vec, i, copy);
 fail2:
     g_free(vec);
     errno = err;
     return NULL;
 }

 void unlock_iovec(struct iovec *vec, abi_ulong target_addr,
         int count, int copy)
 {
     struct target_iovec *target_vec;

     target_vec = lock_user(VERIFY_READ, target_addr,
                            count * sizeof(struct target_iovec), 1);
     if (target_vec) {
         helper_unlock_iovec(target_vec, target_addr, vec, count, copy);
     }

     g_free(vec);
 }

 /*
  * All errnos that freebsd_syscall() returns must be -TARGET_<errcode>.
  */
 static abi_long freebsd_syscall(void *cpu_env, int num, abi_long arg1,
                                 abi_long arg2, abi_long arg3, abi_long arg4,
                                 abi_long arg5, abi_long arg6, abi_long arg7,
                                 abi_long arg8)
 {
     abi_long ret;

     switch (num) {
         /*
          * process system calls
          */
     case TARGET_FREEBSD_NR_exit: /* exit(2) */
         ret = do_bsd_exit(cpu_env, arg1);
         break;

         /*
          * File system calls.
          */
     case TARGET_FREEBSD_NR_read: /* read(2) */
         ret = do_bsd_read(arg1, arg2, arg3);
         break;

     case TARGET_FREEBSD_NR_pread: /* pread(2) */
         ret = do_bsd_pread(cpu_env, arg1, arg2, arg3, arg4, arg5, arg6);
         break;

     case TARGET_FREEBSD_NR_readv: /* readv(2) */
         ret = do_bsd_readv(arg1, arg2, arg3);
         break;

     case TARGET_FREEBSD_NR_preadv: /* preadv(2) */
         ret = do_bsd_preadv(cpu_env, arg1, arg2, arg3, arg4, arg5, arg6);

     case TARGET_FREEBSD_NR_write: /* write(2) */
         ret = do_bsd_write(arg1, arg2, arg3);
         break;

     case TARGET_FREEBSD_NR_pwrite: /* pwrite(2) */
         ret = do_bsd_pwrite(cpu_env, arg1, arg2, arg3, arg4, arg5, arg6);
         break;

     case TARGET_FREEBSD_NR_writev: /* writev(2) */
         ret = do_bsd_writev(arg1, arg2, arg3);
         break;

     case TARGET_FREEBSD_NR_pwritev: /* pwritev(2) */
         ret = do_bsd_pwritev(cpu_env, arg1, arg2, arg3, arg4, arg5, arg6);
         break;

     default:
         qemu_log_mask(LOG_UNIMP, "Unsupported syscall: %d\n", num);
         ret = -TARGET_ENOSYS;
         break;
     }

     return ret;
 }

 /*
  * do_freebsd_syscall() should always have a single exit point at the end so
  * that actions, such as logging of syscall results, can be performed. This
  * as a wrapper around freebsd_syscall() so that actually happens. Since
  * that is a singleton, modern compilers will inline it anyway...
  */
 abi_long do_freebsd_syscall(void *cpu_env, int num, abi_long arg1,
                             abi_long arg2, abi_long arg3, abi_long arg4,
                             abi_long arg5, abi_long arg6, abi_long arg7,
                             abi_long arg8)
 {
     CPUState *cpu = env_cpu(cpu_env);
     int ret;

     trace_guest_user_syscall(cpu, num, arg1, arg2, arg3, arg4, arg5, arg6, arg7, arg8);
     if (do_strace) {
         print_freebsd_syscall(num, arg1, arg2, arg3, arg4, arg5, arg6);
     }

     ret = freebsd_syscall(cpu_env, num, arg1, arg2, arg3, arg4, arg5, arg6,
                           arg7, arg8);
     if (do_strace) {
         print_freebsd_syscall_ret(num, ret);
     }
     trace_guest_user_syscall_ret(cpu, num, ret);

     return ret;
 }

 void syscall_init(void)
 {
 }
	/*
	* BSD syscalls
	*
	* Copyright (c) 2003-2008 Fabrice Bellard
	* Copyright (c) 2013-2014 Stacey D. Son
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License as published by
	* the Free Software Foundation; either version 2 of the License, or
	* (at your option) any later version.
	*
	* This program 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 General Public License for more details.
	*
	* You should have received a copy of the GNU General Public License
	* along with this program; if not, see <http://www.gnu.org/licenses/>.
	*/

	/*
	* We need the FreeBSD "legacy" definitions. Rust needs the FreeBSD 11 system
	* calls since it doesn't use libc at all, so we have to emulate that despite
	* FreeBSD 11 being EOL'd.
	*/
	#define _WANT_FREEBSD11_STAT
	#define _WANT_FREEBSD11_STATFS
	#define _WANT_FREEBSD11_DIRENT
	#define _WANT_KERNEL_ERRNO
	#define _WANT_SEMUN
	#include "qemu/osdep.h"
	#include "qemu/cutils.h"
	#include "qemu/path.h"
	#include <sys/syscall.h>
	#include <sys/param.h>
	#include <sys/sysctl.h>
	#include <utime.h>

	#include "qemu.h"
	#include "signal-common.h"
	#include "user/syscall-trace.h"

	#include "bsd-file.h"
	#include "bsd-proc.h"

	/* I/O */
	safe_syscall3(ssize_t, read, int, fd, void *, buf, size_t, nbytes);
	safe_syscall4(ssize_t, pread, int, fd, void *, buf, size_t, nbytes, off_t,
	offset);
	safe_syscall3(ssize_t, readv, int, fd, const struct iovec *, iov, int, iovcnt);
	safe_syscall4(ssize_t, preadv, int, fd, const struct iovec *, iov, int, iovcnt,
	off_t, offset);

	safe_syscall3(ssize_t, write, int, fd, void *, buf, size_t, nbytes);
	safe_syscall4(ssize_t, pwrite, int, fd, void *, buf, size_t, nbytes, off_t,
	offset);
	safe_syscall3(ssize_t, writev, int, fd, const struct iovec *, iov, int, iovcnt);
	safe_syscall4(ssize_t, pwritev, int, fd, const struct iovec *, iov, int, iovcnt,
	off_t, offset);

	void target_set_brk(abi_ulong new_brk)
	{
	}

	/*
	* errno conversion.
	*/
	abi_long get_errno(abi_long ret)
	{
	if (ret == -1) {
	return -host_to_target_errno(errno);
	} else {
	return ret;
	}
	}

	int host_to_target_errno(int err)
	{
	/*
	* All the BSDs have the property that the error numbers are uniform across
	* all architectures for a given BSD, though they may vary between different
	* BSDs.
	*/
	return err;
	}

	bool is_error(abi_long ret)
	{
	return (abi_ulong)ret >= (abi_ulong)(-4096);
	}

	/*
	* Unlocks a iovec. Unlike unlock_iovec, it assumes the tvec array itself is
	* already locked from target_addr. It will be unlocked as well as all the iovec
	* elements.
	*/
	static void helper_unlock_iovec(struct target_iovec *target_vec,
	abi_ulong target_addr, struct iovec *vec,
	int count, int copy)
	{
	for (int i = 0; i < count; i++) {
	abi_ulong base = tswapal(target_vec[i].iov_base);

	if (vec[i].iov_base) {
	unlock_user(vec[i].iov_base, base, copy ? vec[i].iov_len : 0);
	}
	}
	unlock_user(target_vec, target_addr, 0);
	}

	struct iovec *lock_iovec(int type, abi_ulong target_addr,
	int count, int copy)
	{
	struct target_iovec *target_vec;
	struct iovec *vec;
	abi_ulong total_len, max_len;
	int i;
	int err = 0;

	if (count == 0) {
	errno = 0;
	return NULL;
	}
	if (count < 0 \|\| count > IOV_MAX) {
	errno = EINVAL;
	return NULL;
	}

	vec = g_try_new0(struct iovec, count);
	if (vec == NULL) {
	errno = ENOMEM;
	return NULL;
	}

	target_vec = lock_user(VERIFY_READ, target_addr,
	count * sizeof(struct target_iovec), 1);
	if (target_vec == NULL) {
	err = EFAULT;
	goto fail2;
	}

	max_len = 0x7fffffff & MIN(TARGET_PAGE_MASK, PAGE_MASK);
	total_len = 0;

	for (i = 0; i < count; i++) {
	abi_ulong base = tswapal(target_vec[i].iov_base);
	abi_long len = tswapal(target_vec[i].iov_len);

	if (len < 0) {
	err = EINVAL;
	goto fail;
	} else if (len == 0) {
	/* Zero length pointer is ignored. */
	vec[i].iov_base = 0;
	} else {
	vec[i].iov_base = lock_user(type, base, len, copy);
	/*
	* If the first buffer pointer is bad, this is a fault. But
	* subsequent bad buffers will result in a partial write; this is
	* realized by filling the vector with null pointers and zero
	* lengths.
	*/
	if (!vec[i].iov_base) {
	if (i == 0) {
	err = EFAULT;
	goto fail;
	} else {
	/*
	* Fail all the subsequent addresses, they are already
	* zero'd.
	*/
	goto out;
	}
	}
	if (len > max_len - total_len) {
	len = max_len - total_len;
	}
	}
	vec[i].iov_len = len;
	total_len += len;
	}
	out:
	unlock_user(target_vec, target_addr, 0);
	return vec;

	fail:
	helper_unlock_iovec(target_vec, target_addr, vec, i, copy);
	fail2:
	g_free(vec);
	errno = err;
	return NULL;
	}

	void unlock_iovec(struct iovec *vec, abi_ulong target_addr,
	int count, int copy)
	{
	struct target_iovec *target_vec;

	target_vec = lock_user(VERIFY_READ, target_addr,
	count * sizeof(struct target_iovec), 1);
	if (target_vec) {
	helper_unlock_iovec(target_vec, target_addr, vec, count, copy);
	}

	g_free(vec);
	}

	/*
	* All errnos that freebsd_syscall() returns must be -TARGET_<errcode>.
	*/
	static abi_long freebsd_syscall(void *cpu_env, int num, abi_long arg1,
	abi_long arg2, abi_long arg3, abi_long arg4,
	abi_long arg5, abi_long arg6, abi_long arg7,
	abi_long arg8)
	{
	abi_long ret;

	switch (num) {
	/*
	* process system calls
	*/
	case TARGET_FREEBSD_NR_exit: /* exit(2) */
	ret = do_bsd_exit(cpu_env, arg1);
	break;

	/*
	* File system calls.
	*/
	case TARGET_FREEBSD_NR_read: /* read(2) */
	ret = do_bsd_read(arg1, arg2, arg3);
	break;

	case TARGET_FREEBSD_NR_pread: /* pread(2) */
	ret = do_bsd_pread(cpu_env, arg1, arg2, arg3, arg4, arg5, arg6);
	break;

	case TARGET_FREEBSD_NR_readv: /* readv(2) */
	ret = do_bsd_readv(arg1, arg2, arg3);
	break;

	case TARGET_FREEBSD_NR_preadv: /* preadv(2) */
	ret = do_bsd_preadv(cpu_env, arg1, arg2, arg3, arg4, arg5, arg6);

	case TARGET_FREEBSD_NR_write: /* write(2) */
	ret = do_bsd_write(arg1, arg2, arg3);
	break;

	case TARGET_FREEBSD_NR_pwrite: /* pwrite(2) */
	ret = do_bsd_pwrite(cpu_env, arg1, arg2, arg3, arg4, arg5, arg6);
	break;

	case TARGET_FREEBSD_NR_writev: /* writev(2) */
	ret = do_bsd_writev(arg1, arg2, arg3);
	break;

	case TARGET_FREEBSD_NR_pwritev: /* pwritev(2) */
	ret = do_bsd_pwritev(cpu_env, arg1, arg2, arg3, arg4, arg5, arg6);
	break;

	default:
	qemu_log_mask(LOG_UNIMP, "Unsupported syscall: %d\n", num);
	ret = -TARGET_ENOSYS;
	break;
	}

	return ret;
	}

	/*
	* do_freebsd_syscall() should always have a single exit point at the end so
	* that actions, such as logging of syscall results, can be performed. This
	* as a wrapper around freebsd_syscall() so that actually happens. Since
	* that is a singleton, modern compilers will inline it anyway...
	*/
	abi_long do_freebsd_syscall(void *cpu_env, int num, abi_long arg1,
	abi_long arg2, abi_long arg3, abi_long arg4,
	abi_long arg5, abi_long arg6, abi_long arg7,
	abi_long arg8)
	{
	CPUState *cpu = env_cpu(cpu_env);
	int ret;

	trace_guest_user_syscall(cpu, num, arg1, arg2, arg3, arg4, arg5, arg6, arg7, arg8);
	if (do_strace) {
	print_freebsd_syscall(num, arg1, arg2, arg3, arg4, arg5, arg6);
	}

	ret = freebsd_syscall(cpu_env, num, arg1, arg2, arg3, arg4, arg5, arg6,
	arg7, arg8);
	if (do_strace) {
	print_freebsd_syscall_ret(num, ret);
	}
	trace_guest_user_syscall_ret(cpu, num, ret);

	return ret;
	}

	void syscall_init(void)
	{
	}