public static void HandlePageFault(Process process, uint faultType, Pointer faultAddress, Pointer faultIP, out Pointer physicalPage, out uint permission)
{
// Object invariants of Process
Contract.Assume(process.Space.GhostOwner == process);
Contract.Assume(process.Space.Head.GhostOwner == process);
// Never map page 0
if (faultAddress.ToUInt32() < Arch.ArchDefinition.PageSize)
{
physicalPage = Pointer.Zero;
permission = MemoryRegion.FALUT_NONE;
return;
}
SyscallProfiler.EnterPageFault();
var space = process.Space;
var region = space.Find(faultAddress);
if (region != null && (faultType & region.Access) != 0)
{
/*
* Check whether the kernel has allocated a page for this address,
* which might be the case due to UserPtr.Read() / UserPtr.Write().
*/
var mapped_in_page = space.UserToVirt(new UserPtr(faultAddress));
if (mapped_in_page != Pointer.Zero)
{
physicalPage = PageIndex(mapped_in_page);
permission = region.Access & MemoryRegion.FAULT_MASK;
return;
}
// If the page is a shared page from Linux, we'll need to ask linux to grab the page
// Otherwise let's just allocate a fresh one.
var shared_memory_region = IsAlienSharedRegion(region);
var ghost_page_from_fresh_memory = false;
ByteBufferRef buf;
if (shared_memory_region)
{
buf = Globals.LinuxMemoryAllocator.GetUserPage(process, faultType, ToShadowProcessAddress(faultAddress, region));
if (!buf.isValid)
{
Arch.Console.WriteLine("pager: cannot map in alien page.");
space.DumpAll();
physicalPage = Pointer.Zero;
permission = MemoryRegion.FALUT_NONE;
return;
}
}
else
{
buf = Globals.PageAllocator.AllocPage();
ghost_page_from_fresh_memory = true;
if (!buf.isValid)
{
Arch.Console.WriteLine("Cannot allocate new pages");
Utils.Panic();
}
if (region.BackingFile != null)
{
var rel_pos = (PageIndex(faultAddress) - region.StartAddress);
uint pos = (uint)((ulong)rel_pos + region.FileOffset);
var readSizeLong = region.FileSize - rel_pos;
if (readSizeLong < 0)
{
readSizeLong = 0;
}
else if (readSizeLong > Arch.ArchDefinition.PageSize)
{
readSizeLong = Arch.ArchDefinition.PageSize;
}
int readSize = (int)readSizeLong;
Contract.Assert(region.BackingFile.GhostOwner == process);
var r = region.BackingFile.Read(buf, 0, readSize, ref pos);
if (r < 0)
{
r = 0;
}
Utils.Assert(r <= Arch.ArchDefinition.PageSize);
if (r < Arch.ArchDefinition.PageSize)
{
buf.ClearAfter(r);
}
}
else
{
buf.Clear();
}
}
Contract.Assert(shared_memory_region ^ ghost_page_from_fresh_memory);
var page = new Pointer(buf.Location);
space.AddIntoWorkingSet(new UserPtr(PageIndex(faultAddress)), page);
SyscallProfiler.ExitPageFault();
physicalPage = page;
permission = region.Access & MemoryRegion.FAULT_MASK;
return;
}
else
{
/*
* TODO: mmap2 enables the application requests an automatically expandable
* region (e.g., a stack)
*
* The feature doesn't seem to be actively used by the applications, since
* both the C runtime and the pthread library initializes stack explicitly.
*
* The feature is currently unimplemented.
*/
}
physicalPage = Pointer.Zero;
permission = MemoryRegion.FALUT_NONE;
return;
}
public static int socketcall(Thread current, ref Arch.ExceptionRegisters regs, int call, UserPtr argPtr)
{
int err = 0;
int a0, a1, a2, a3, a4, a5;
SyscallProfiler.EnterSocketcall(call);
switch (call)
{
case SYS_SOCKET:
if (argPtr.Read(current, out a0) != 0 || (argPtr + sizeof(int)).Read(current, out a1) != 0 ||
(argPtr + sizeof(int) * 2).Read(current, out a2) != 0)
{
return(-ErrorCode.EFAULT);
}
err = Socket(current, ref regs, a0, a1, a2);
break;
case SYS_BIND:
if (argPtr.Read(current, out a0) != 0 || (argPtr + sizeof(int)).Read(current, out a1) != 0 ||
(argPtr + sizeof(int) * 2).Read(current, out a2) != 0)
{
return(-ErrorCode.EFAULT);
}
err = Bind(current, ref regs, a0, new UserPtr(a1), a2);
break;
case SYS_CONNECT:
if (argPtr.Read(current, out a0) != 0 || (argPtr + sizeof(int)).Read(current, out a1) != 0 ||
(argPtr + sizeof(int) * 2).Read(current, out a2) != 0)
{
return(-ErrorCode.EFAULT);
}
err = Connect(current, ref regs, a0, new UserPtr(a1), a2);
break;
case SYS_GETSOCKNAME:
if (argPtr.Read(current, out a0) != 0 || (argPtr + sizeof(int)).Read(current, out a1) != 0 ||
(argPtr + sizeof(int) * 2).Read(current, out a2) != 0)
{
return(-ErrorCode.EFAULT);
}
err = Getsockname(current, ref regs, a0, new UserPtr(a1), new UserPtr(a2));
break;
case SYS_SENDTO:
if (argPtr.Read(current, out a0) != 0 || (argPtr + sizeof(int)).Read(current, out a1) != 0 ||
(argPtr + sizeof(int) * 2).Read(current, out a2) != 0 || (argPtr + sizeof(int) * 3).Read(current, out a3) != 0 ||
(argPtr + sizeof(int) * 4).Read(current, out a4) != 0 || (argPtr + sizeof(int) * 5).Read(current, out a5) != 0)
{
return(-ErrorCode.EFAULT);
}
err = Sendto(current, a0, new UserPtr(a1), a2, a3, new UserPtr(a4), a5);
break;
case SYS_RECVFROM:
if (argPtr.Read(current, out a0) != 0 || (argPtr + sizeof(int)).Read(current, out a1) != 0 ||
(argPtr + sizeof(int) * 2).Read(current, out a2) != 0 || (argPtr + sizeof(int) * 3).Read(current, out a3) != 0 ||
(argPtr + sizeof(int) * 4).Read(current, out a4) != 0 || (argPtr + sizeof(int) * 5).Read(current, out a5) != 0)
{
return(-ErrorCode.EFAULT);
}
err = RecvFrom(current, a0, new UserPtr(a1), a2, a3, new UserPtr(a4), new UserPtr(a5));
break;
case SYS_SHUTDOWN:
if (argPtr.Read(current, out a0) != 0 || (argPtr + sizeof(int)).Read(current, out a1) != 0)
{
return(-ErrorCode.EFAULT);
}
err = Shutdown(current, a0, a1);
break;
case SYS_SETSOCKOPT:
if (argPtr.Read(current, out a0) != 0 || (argPtr + sizeof(int)).Read(current, out a1) != 0 ||
(argPtr + sizeof(int) * 2).Read(current, out a2) != 0 || (argPtr + sizeof(int) * 3).Read(current, out a3) != 0 ||
(argPtr + sizeof(int) * 4).Read(current, out a4) != 0)
{
return(-ErrorCode.EFAULT);
}
err = Setsockopt(current, ref regs, a0, a1, a2, new UserPtr(a3), a4);
break;
case SYS_GETSOCKOPT:
if (argPtr.Read(current, out a0) != 0 || (argPtr + sizeof(int)).Read(current, out a1) != 0 ||
(argPtr + sizeof(int) * 2).Read(current, out a2) != 0 || (argPtr + sizeof(int) * 3).Read(current, out a3) != 0 ||
(argPtr + sizeof(int) * 4).Read(current, out a4) != 0)
{
return(-ErrorCode.EFAULT);
}
err = Getsockopt(current, ref regs, a0, a1, a2, new UserPtr(a3), new UserPtr(a4));
break;
default:
Arch.Console.Write("Unimplemented socketcall ");
Arch.Console.Write(call);
Arch.Console.WriteLine();
err = -1;
break;
}
SyscallProfiler.ExitSocketcall(call);
return(err);
}
public static int Open(Thread current, ref Arch.ExceptionRegisters regs, UserPtr filenamePtr, int flags, int mode)
{
// TODO: Deal with current path
var filenameBuf = new byte[PATH_MAX];
var ret = filenamePtr.ReadString(current, filenameBuf);
var proc = current.Parent;
int fd = 0;
GenericINode inode = null;
var startTime = Arch.NativeMethods.l4api_get_system_clock();
if (Util.ByteStringCompare(filenameBuf, IPCFilename.GetByteString()) == 0)
{
fd = proc.GetUnusedFd();
inode = BinderINode.Instance;
}
else if (Util.ByteStringCompare(filenameBuf, AshmemFileName.GetByteString()) == 0)
{
var linux_fd = Arch.ArchFS.OpenAndReturnLinuxFd(current.Parent.helperPid, new ASCIIString(filenameBuf), flags, mode);
if (linux_fd < 0)
{
return(linux_fd);
}
inode = new AshmemINode(linux_fd, current.Parent.helperPid);
fd = proc.GetUnusedFd();
}
else if (SecureFS.IsSecureFS(current, filenameBuf))
{
var completion = SecureFS.OpenAndReadPagesAsync(current, filenameBuf, flags, mode);
if (completion == null)
{
return(-ErrorCode.ENOMEM);
}
Globals.CompletionQueue.Enqueue(completion);
current.SaveState(ref regs);
current.AsyncReturn = true;
return(0);
}
else
{
var filename_len = ret;
var completion = Arch.ArchFS.OpenAndGetSizeAsync(current, filenameBuf, flags, mode);
if (completion == null)
{
return(-ErrorCode.ENOMEM);
}
Globals.CompletionQueue.Enqueue(completion);
current.SaveState(ref regs);
current.AsyncReturn = true;
return(0);
}
if (fd > 0)
{
var file = new File(proc, inode, flags, mode);
proc.InstallFd(fd, file);
}
if (SyscallProfiler.Enable)
{
var endTime = Arch.NativeMethods.l4api_get_system_clock();
SyscallProfiler.AccountOpen((int)inode.kind, (long)(endTime - startTime));
}
return(fd);
}