Re: [Qemu-devel] [PATCH] linux-user EFAULT implementation

[Stuart Anderson <anderson@netsweng.com>]

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On Mon, 9 Jul 2007, Stuart Anderson wrote:

> Attached is a diff ...

Here's the diff.


                                 Stuart

Stuart R. Anderson                               anderson@netsweng.com
Network & Software Engineering                   http://www.netsweng.com/
1024D/37A79149:                                  0791 D3B8 9A4C 2CDC A31F
                                                  BD03 0A62 E534 37A7 9149

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*** linux-user/syscall.c	2007-07-09 07:33:46.000000000 -0400
--- linux-user/syscall.c.stu	2007-07-09 07:01:12.000000000 -0400
***************
*** 522,550 ****
      return ret;
  }
  
! static inline long copy_from_user_sockaddr(struct sockaddr *addr,
                                             target_ulong target_addr,
!                                            socklen_t len)
  {
      long ret = 0;
!     struct target_sockaddr *target_saddr = (struct target_sockaddr *)target_addr;
  
!     if( (ret=access_ok(VERIFY_READ,target_saddr,len)) != 0 ) return ret;
      memcpy(addr, target_saddr, len);
      addr->sa_family = tswap16(target_saddr->sa_family);
      return ret;
  }
  
! static inline long copy_to_user_sockaddr(target_ulong target_addr,
                                             struct sockaddr *addr,
!                                            socklen_t len)
  {
      long ret = 0;
!     struct target_sockaddr *target_saddr = (struct target_sockaddr *)target_addr;
  
!     if( (ret=access_ok(VERIFY_WRITE,target_saddr,len)) != 0 ) return ret;
      memcpy(target_saddr, addr, len);
      target_saddr->sa_family = tswap16(addr->sa_family);
      return ret;
  }
  
--- 522,554 ----
      return ret;
  }
  
! static inline long target_to_host_sockaddr(struct sockaddr *addr,
                                             target_ulong target_addr,
!                                            socklen_t len,
!                                            int pg_access)
  {
      long ret = 0;
!     struct target_sockaddr *target_saddr;
  
!     if( (ret=lock_and_check_user_struct(&target_saddr,target_addr,len,1,pg_access)) != 0 ) return ret;
      memcpy(addr, target_saddr, len);
      addr->sa_family = tswap16(target_saddr->sa_family);
+     unlock_user(target_saddr, target_addr, 0);
      return ret;
  }
  
! static inline long host_to_target_sockaddr(target_ulong target_addr,
                                             struct sockaddr *addr,
!                                            socklen_t len,
!                                            int pg_access)
  {
      long ret = 0;
!     struct target_sockaddr *target_saddr;
  
!     if( (ret=lock_and_check_user_struct(&target_saddr,target_addr,len,1,pg_access)) != 0 ) return ret;
      memcpy(target_saddr, addr, len);
      target_saddr->sa_family = tswap16(addr->sa_family);
+     unlock_user(target_saddr, target_addr, len);
      return ret;
  }
  
***************
*** 909,915 ****
      long ret = 0;
      void *addr = alloca(addrlen);
      
!     if( (ret=copy_from_user_sockaddr(addr, target_addr, addrlen)) != 0 ) return ret;
      return get_errno(bind(sockfd, addr, addrlen));
  }
  
--- 913,919 ----
      long ret = 0;
      void *addr = alloca(addrlen);
      
!     if( (ret=target_to_host_sockaddr(addr, target_addr, addrlen,PAGE_READ)) != 0 ) return ret;
      return get_errno(bind(sockfd, addr, addrlen));
  }
  
***************
*** 919,925 ****
      long ret = 0;
      void *addr = alloca(addrlen);
      
!     if( (ret=copy_from_user_sockaddr(addr, target_addr, addrlen)) != 0 ) return ret;
      return get_errno(connect(sockfd, addr, addrlen));
  }
  
--- 923,929 ----
      long ret = 0;
      void *addr = alloca(addrlen);
      
!     if( (ret=target_to_host_sockaddr(addr, target_addr, addrlen,PAGE_READ)) != 0 ) return ret;
      return get_errno(connect(sockfd, addr, addrlen));
  }
  
***************
*** 944,956 ****
          msg.msg_namelen = tswap32(msgp->msg_namelen);
          msg.msg_name = alloca(msg.msg_namelen);
          if( send ) {
!           if( (ret=copy_from_user_sockaddr(msg.msg_name, tswapl(msgp->msg_name),
!                                 msg.msg_namelen)) != 0 ) return ret;
          } else {
! 	  /* FIXME
!           if( (ret=copy_from_user_sockaddr(msg.msg_name, tswapl(msgp->msg_name),
                                  msg.msg_namelen,PAGE_WRITE)) != 0 ) return ret;
- 				*/
  	}
      } else {
          msg.msg_name = NULL;
--- 948,958 ----
          msg.msg_namelen = tswap32(msgp->msg_namelen);
          msg.msg_name = alloca(msg.msg_namelen);
          if( send ) {
!           if( (ret=target_to_host_sockaddr(msg.msg_name, tswapl(msgp->msg_name),
!                                 msg.msg_namelen,PAGE_READ)) != 0 ) return ret;
          } else {
!           if( (ret=target_to_host_sockaddr(msg.msg_name, tswapl(msgp->msg_name),
                                  msg.msg_namelen,PAGE_WRITE)) != 0 ) return ret;
  	}
      } else {
          msg.msg_name = NULL;
***************
*** 991,997 ****
  
      ret = get_errno(accept(fd, addr, &addrlen));
      if (!is_error(ret)) {
!         if( (ret2=copy_to_user_sockaddr(target_addr, addr, addrlen)) != 0 ) return ret2;
          tput32(target_addrlen, addrlen);
      }
      return ret;
--- 993,999 ----
  
      ret = get_errno(accept(fd, addr, &addrlen));
      if (!is_error(ret)) {
!         if( (ret2=host_to_target_sockaddr(target_addr, addr, addrlen, PAGE_WRITE)) != 0 ) return ret2;
          tput32(target_addrlen, addrlen);
      }
      return ret;
***************
*** 1010,1016 ****
  
      ret = get_errno(getpeername(fd, addr, &addrlen));
      if (!is_error(ret)) {
!         if( (ret2=copy_to_user_sockaddr(target_addr, addr, addrlen)) != 0 ) return ret2;
          if( (ret2=page_check_range(target_addrlen,sizeof(socklen_t),PAGE_WRITE)) != 0 ) return ret2;
          tput32(target_addrlen, addrlen);
      }
--- 1012,1018 ----
  
      ret = get_errno(getpeername(fd, addr, &addrlen));
      if (!is_error(ret)) {
!         if( (ret2=host_to_target_sockaddr(target_addr, addr, addrlen, PAGE_WRITE)) != 0 ) return ret2;
          if( (ret2=page_check_range(target_addrlen,sizeof(socklen_t),PAGE_WRITE)) != 0 ) return ret2;
          tput32(target_addrlen, addrlen);
      }
***************
*** 1030,1036 ****
  
      ret = get_errno(getsockname(fd, addr, &addrlen));
      if (!is_error(ret)) {
!         if( (ret2=copy_to_user_sockaddr(target_addr, addr, addrlen)) ) return ret2;
          tput32(target_addrlen, addrlen);
      }
      return ret;
--- 1032,1038 ----
  
      ret = get_errno(getsockname(fd, addr, &addrlen));
      if (!is_error(ret)) {
!         if( (ret2=host_to_target_sockaddr(target_addr, addr, addrlen, PAGE_WRITE)) ) return ret2;
          tput32(target_addrlen, addrlen);
      }
      return ret;
***************
*** 1060,1066 ****
      if( (ret=lock_and_check_user_struct(&host_msg,msg,len,1,PAGE_READ)) != 0 ) return ret;
      if (target_addr) {
          addr = alloca(addrlen);
!         if( (ret=copy_from_user_sockaddr(addr, target_addr, addrlen)) != 0 ) return ret;
          ret = get_errno(sendto(fd, host_msg, len, flags, addr, addrlen));
      } else {
          ret = get_errno(send(fd, host_msg, len, flags));
--- 1062,1068 ----
      if( (ret=lock_and_check_user_struct(&host_msg,msg,len,1,PAGE_READ)) != 0 ) return ret;
      if (target_addr) {
          addr = alloca(addrlen);
!         if( (ret=target_to_host_sockaddr(addr, target_addr, addrlen, PAGE_READ)) != 0 ) return ret;
          ret = get_errno(sendto(fd, host_msg, len, flags, addr, addrlen));
      } else {
          ret = get_errno(send(fd, host_msg, len, flags));
***************
*** 1088,1094 ****
      }
      if (!is_error(ret)) {
          if (target_addr) {
!             if( (ret2=copy_to_user_sockaddr(target_addr, addr, addrlen)) != 0 ) return ret2;
              tput32(target_addrlen, addrlen);
          }
          unlock_user(host_msg, msg, len);
--- 1090,1096 ----
      }
      if (!is_error(ret)) {
          if (target_addr) {
!             if( (ret2=host_to_target_sockaddr(target_addr, addr, addrlen, PAGE_WRITE)) != 0 ) return ret2;
              tput32(target_addrlen, addrlen);
          }
          unlock_user(host_msg, msg, len);