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Fix virtual address overflow near ulong limit (#2044)

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* Fix virtual address overflow near ulong limit

* Fix comments

* Improve overflow checking for large size values

* Add overflow checking to AddressSpaceManager class

* Add overflow protection to read and write functions
This commit is contained in:
Caian Benedicto 2021-02-28 07:48:04 -03:00 committed by GitHub
parent fd9d16c3b3
commit f7b2daf5ec
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GPG key ID: 4AEE18F83AFDEB23
2 changed files with 134 additions and 32 deletions
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98
Ryujinx.Cpu/MemoryManager.cs
View file

@ -83,6 +83,8 @@ namespace Ryujinx.Cpu
/// <param name="size">Size to be mapped</param>
public void Map(ulong va, ulong pa, ulong size)
{
AssertValidAddressAndSize(va, size);
ulong remainingSize = size;
ulong oVa = va;
ulong oPa = pa;
@ -110,6 +112,8 @@ namespace Ryujinx.Cpu
return;
}
AssertValidAddressAndSize(va, size);
UnmapEvent?.Invoke(va, size);
ulong remainingSize = size;
@ -214,6 +218,8 @@ namespace Ryujinx.Cpu
{
try
{
AssertValidAddressAndSize(va, (ulong)data.Length);
if (IsContiguousAndMapped(va, data.Length))
{
data.CopyTo(_backingMemory.GetSpan(GetPhysicalAddressInternal(va), data.Length));
@ -345,6 +351,23 @@ namespace Ryujinx.Cpu
return ref _backingMemory.GetRef<T>(GetPhysicalAddressInternal(va));
}
/// <summary>
/// Computes the number of pages in a virtual address range.
/// </summary>
/// <param name="va">Virtual address of the range</param>
/// <param name="size">Size of the range</param>
/// <param name="startVa">The virtual address of the beginning of the first page</param>
/// <remarks>This function does not differentiate between allocated and unallocated pages.</remarks>
[MethodImpl(MethodImplOptions.AggressiveInlining)]
private int GetPagesCount(ulong va, uint size, out ulong startVa)
{
// WARNING: Always check if ulong does not overflow during the operations.
startVa = va & ~(ulong)PageMask;
ulong vaSpan = (va - startVa + size + PageMask) & ~(ulong)PageMask;
return (int)(vaSpan / PageSize);
}
private void ThrowMemoryNotContiguous() => throw new MemoryNotContiguousException();
[MethodImpl(MethodImplOptions.AggressiveInlining)]
@ -353,16 +376,12 @@ namespace Ryujinx.Cpu
[MethodImpl(MethodImplOptions.AggressiveInlining)]
private bool IsContiguous(ulong va, int size)
{
if (!ValidateAddress(va))
if (!ValidateAddress(va) || !ValidateAddressAndSize(va, (ulong)size))
{
return false;
}
ulong endVa = (va + (ulong)size + PageMask) & ~(ulong)PageMask;
va &= ~(ulong)PageMask;
int pages = (int)((endVa - va) / PageSize);
int pages = GetPagesCount(va, (uint)size, out va);
for (int page = 0; page < pages - 1; page++)
{
@ -391,16 +410,12 @@ namespace Ryujinx.Cpu
/// <returns>Array of physical regions</returns>
public (ulong address, ulong size)[] GetPhysicalRegions(ulong va, ulong size)
{
if (!ValidateAddress(va))
if (!ValidateAddress(va) || !ValidateAddressAndSize(va, size))
{
return null;
}
ulong endVa = (va + size + PageMask) & ~(ulong)PageMask;
va &= ~(ulong)PageMask;
int pages = (int)((endVa - va) / PageSize);
int pages = GetPagesCount(va, (uint)size, out va);
List<(ulong, ulong)> regions = new List<(ulong, ulong)>();
@ -441,6 +456,8 @@ namespace Ryujinx.Cpu
try
{
AssertValidAddressAndSize(va, (ulong)data.Length);
int offset = 0, size;
if ((va & PageMask) != 0)
@ -485,11 +502,14 @@ namespace Ryujinx.Cpu
return true;
}
ulong endVa = (va + size + PageMask) & ~(ulong)PageMask;
if (!ValidateAddressAndSize(va, size))
{
return false;
}
va &= ~(ulong)PageMask;
int pages = GetPagesCount(va, (uint)size, out va);
while (va < endVa)
for (int page = 0; page < pages; page++)
{
if (!IsMapped(va))
{
@ -523,6 +543,32 @@ namespace Ryujinx.Cpu
return va < _addressSpaceSize;
}
/// <summary>
/// Checks if the combination of virtual address and size is part of the addressable space.
/// </summary>
/// <param name="va">Virtual address of the range</param>
/// <param name="size">Size of the range in bytes</param>
/// <returns>True if the combination of virtual address and size is part of the addressable space</returns>
private bool ValidateAddressAndSize(ulong va, ulong size)
{
ulong endVa = va + size;
return endVa >= va && endVa >= size && endVa <= _addressSpaceSize;
}
/// <summary>
/// Ensures the combination of virtual address and size is part of the addressable space.
/// </summary>
/// <param name="va">Virtual address of the range</param>
/// <param name="size">Size of the range in bytes</param>
/// <exception cref="InvalidMemoryRegionException">Throw when the memory region specified outside the addressable space</exception>
private void AssertValidAddressAndSize(ulong va, ulong size)
{
if (!ValidateAddressAndSize(va, size))
{
throw new InvalidMemoryRegionException($"va=0x{va:X16}, size=0x{size:X16}");
}
}
/// <summary>
/// Performs address translation of the address inside a CPU mapped memory range.
/// </summary>
@ -555,6 +601,8 @@ namespace Ryujinx.Cpu
/// <param name="protection">Memory protection to set</param>
public void TrackingReprotect(ulong va, ulong size, MemoryPermission protection)
{
AssertValidAddressAndSize(va, size);
// Protection is inverted on software pages, since the default value is 0.
protection = (~protection) & MemoryPermission.ReadAndWrite;
@ -565,12 +613,13 @@ namespace Ryujinx.Cpu
_ => 3L << PointerTagBit
};
ulong endVa = (va + size + PageMask) & ~(ulong)PageMask;
int pages = GetPagesCount(va, (uint)size, out va);
ulong pageStart = va >> PageBits;
long invTagMask = ~(0xffffL << 48);
while (va < endVa)
for (int page = 0; page < pages; page++)
{
ref long pageRef = ref _pageTable.GetRef<long>((va >> PageBits) * PteSize);
ref long pageRef = ref _pageTable.GetRef<long>(pageStart * PteSize);
long pte;
@ -580,7 +629,7 @@ namespace Ryujinx.Cpu
}
while (Interlocked.CompareExchange(ref pageRef, (pte & invTagMask) | tag, pte) != pte);
va += PageSize;
pageStart++;
}
}
@ -627,17 +676,20 @@ namespace Ryujinx.Cpu
/// <param name="size">Size of the region</param>
public void SignalMemoryTracking(ulong va, ulong size, bool write)
{
AssertValidAddressAndSize(va, size);
// We emulate guard pages for software memory access. This makes for an easy transition to
// tracking using host guard pages in future, but also supporting platforms where this is not possible.
// Write tag includes read protection, since we don't have any read actions that aren't performed before write too.
long tag = (write ? 3L : 1L) << PointerTagBit;
ulong endVa = (va + size + PageMask) & ~(ulong)PageMask;
int pages = GetPagesCount(va, (uint)size, out va);
ulong pageStart = va >> PageBits;
while (va < endVa)
for (int page = 0; page < pages; page++)
{
ref long pageRef = ref _pageTable.GetRef<long>((va >> PageBits) * PteSize);
ref long pageRef = ref _pageTable.GetRef<long>(pageStart * PteSize);
long pte;
@ -649,7 +701,7 @@ namespace Ryujinx.Cpu
break;
}
va += PageSize;
pageStart++;
}
}

68
Ryujinx.Memory/AddressSpaceManager.cs
View file

@ -64,6 +64,8 @@ namespace Ryujinx.Memory
/// <param name="size">Size to be mapped</param>
public void Map(ulong va, ulong pa, ulong size)
{
AssertValidAddressAndSize(va, size);
while (size != 0)
{
PtMap(va, pa);
@ -81,6 +83,8 @@ namespace Ryujinx.Memory
/// <param name="size">Size of the range to be unmapped</param>
public void Unmap(ulong va, ulong size)
{
AssertValidAddressAndSize(va, size);
while (size != 0)
{
PtUnmap(va);
@ -138,6 +142,8 @@ namespace Ryujinx.Memory
return;
}
AssertValidAddressAndSize(va, (ulong)data.Length);
if (IsContiguousAndMapped(va, data.Length))
{
data.CopyTo(_backingMemory.GetSpan(GetPhysicalAddressInternal(va), data.Length));
@ -254,6 +260,23 @@ namespace Ryujinx.Memory
return ref _backingMemory.GetRef<T>(GetPhysicalAddressInternal(va));
}
/// <summary>
/// Computes the number of pages in a virtual address range.
/// </summary>
/// <param name="va">Virtual address of the range</param>
/// <param name="size">Size of the range</param>
/// <param name="startVa">The virtual address of the beginning of the first page</param>
/// <remarks>This function does not differentiate between allocated and unallocated pages.</remarks>
[MethodImpl(MethodImplOptions.AggressiveInlining)]
private int GetPagesCount(ulong va, uint size, out ulong startVa)
{
// WARNING: Always check if ulong does not overflow during the operations.
startVa = va & ~(ulong)PageMask;
ulong vaSpan = (va - startVa + size + PageMask) & ~(ulong)PageMask;
return (int)(vaSpan / PageSize);
}
private void ThrowMemoryNotContiguous() => throw new MemoryNotContiguousException();
[MethodImpl(MethodImplOptions.AggressiveInlining)]
@ -262,16 +285,12 @@ namespace Ryujinx.Memory
[MethodImpl(MethodImplOptions.AggressiveInlining)]
private bool IsContiguous(ulong va, int size)
{
if (!ValidateAddress(va))
if (!ValidateAddress(va) || !ValidateAddressAndSize(va, (ulong)size))
{
return false;
}
ulong endVa = (va + (ulong)size + PageMask) & ~(ulong)PageMask;
va &= ~(ulong)PageMask;
int pages = (int)((endVa - va) / PageSize);
int pages = GetPagesCount(va, (uint)size, out va);
for (int page = 0; page < pages - 1; page++)
{
@ -310,6 +329,8 @@ namespace Ryujinx.Memory
return;
}
AssertValidAddressAndSize(va, (ulong)data.Length);
int offset = 0, size;
if ((va & PageMask) != 0)
@ -362,11 +383,14 @@ namespace Ryujinx.Memory
return true;
}
ulong endVa = (va + size + PageMask) & ~(ulong)PageMask;
if (!ValidateAddressAndSize(va, size))
{
return false;
}
va &= ~(ulong)PageMask;
int pages = GetPagesCount(va, (uint)size, out va);
while (va < endVa)
for (int page = 0; page < pages; page++)
{
if (!IsMapped(va))
{
@ -384,6 +408,32 @@ namespace Ryujinx.Memory
return va < _addressSpaceSize;
}
/// <summary>
/// Checks if the combination of virtual address and size is part of the addressable space.
/// </summary>
/// <param name="va">Virtual address of the range</param>
/// <param name="size">Size of the range in bytes</param>
/// <returns>True if the combination of virtual address and size is part of the addressable space</returns>
private bool ValidateAddressAndSize(ulong va, ulong size)
{
ulong endVa = va + size;
return endVa >= va && endVa >= size && endVa <= _addressSpaceSize;
}
/// <summary>
/// Ensures the combination of virtual address and size is part of the addressable space.
/// </summary>
/// <param name="va">Virtual address of the range</param>
/// <param name="size">Size of the range in bytes</param>
/// <exception cref="InvalidMemoryRegionException">Throw when the memory region specified outside the addressable space</exception>
private void AssertValidAddressAndSize(ulong va, ulong size)
{
if (!ValidateAddressAndSize(va, size))
{
throw new InvalidMemoryRegionException($"va=0x{va:X16}, size=0x{size:X16}");
}
}
/// <summary>
/// Performs address translation of the address inside a mapped memory range.
/// </summary>