diff options
Diffstat (limited to 'pkg/usermem/addr.go')
| -rw-r--r-- | pkg/usermem/addr.go | 125 |
1 files changed, 0 insertions, 125 deletions
diff --git a/pkg/usermem/addr.go b/pkg/usermem/addr.go deleted file mode 100644 index c4100481e..000000000 --- a/pkg/usermem/addr.go +++ /dev/null @@ -1,125 +0,0 @@ -// Copyright 2018 The gVisor Authors. -// -// Licensed under the Apache License, Version 2.0 (the "License"); -// you may not use this file except in compliance with the License. -// You may obtain a copy of the License at -// -// http://www.apache.org/licenses/LICENSE-2.0 -// -// Unless required by applicable law or agreed to in writing, software -// distributed under the License is distributed on an "AS IS" BASIS, -// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. -// See the License for the specific language governing permissions and -// limitations under the License. - -package usermem - -import ( - "fmt" -) - -// Addr represents a generic virtual address. -// -// +stateify savable -type Addr uintptr - -// AddLength adds the given length to start and returns the result. ok is true -// iff adding the length did not overflow the range of Addr. -// -// Note: This function is usually used to get the end of an address range -// defined by its start address and length. Since the resulting end is -// exclusive, end == 0 is technically valid, and corresponds to a range that -// extends to the end of the address space, but ok will be false. This isn't -// expected to ever come up in practice. -func (v Addr) AddLength(length uint64) (end Addr, ok bool) { - end = v + Addr(length) - // The second half of the following check is needed in case uintptr is - // smaller than 64 bits. - ok = end >= v && length <= uint64(^Addr(0)) - return -} - -// RoundDown returns the address rounded down to the nearest page boundary. -func (v Addr) RoundDown() Addr { - return v & ^Addr(PageSize-1) -} - -// RoundUp returns the address rounded up to the nearest page boundary. ok is -// true iff rounding up did not wrap around. -func (v Addr) RoundUp() (addr Addr, ok bool) { - addr = Addr(v + PageSize - 1).RoundDown() - ok = addr >= v - return -} - -// MustRoundUp is equivalent to RoundUp, but panics if rounding up wraps -// around. -func (v Addr) MustRoundUp() Addr { - addr, ok := v.RoundUp() - if !ok { - panic(fmt.Sprintf("usermem.Addr(%d).RoundUp() wraps", v)) - } - return addr -} - -// HugeRoundDown returns the address rounded down to the nearest huge page -// boundary. -func (v Addr) HugeRoundDown() Addr { - return v & ^Addr(HugePageSize-1) -} - -// HugeRoundUp returns the address rounded up to the nearest huge page boundary. -// ok is true iff rounding up did not wrap around. -func (v Addr) HugeRoundUp() (addr Addr, ok bool) { - addr = Addr(v + HugePageSize - 1).HugeRoundDown() - ok = addr >= v - return -} - -// PageOffset returns the offset of v into the current page. -func (v Addr) PageOffset() uint64 { - return uint64(v & Addr(PageSize-1)) -} - -// IsPageAligned returns true if v.PageOffset() == 0. -func (v Addr) IsPageAligned() bool { - return v.PageOffset() == 0 -} - -// AddrRange is a range of Addrs. -// -// type AddrRange <generated by go_generics> - -// ToRange returns [v, v+length). -func (v Addr) ToRange(length uint64) (AddrRange, bool) { - end, ok := v.AddLength(length) - return AddrRange{v, end}, ok -} - -// IsPageAligned returns true if ar.Start.IsPageAligned() and -// ar.End.IsPageAligned(). -func (ar AddrRange) IsPageAligned() bool { - return ar.Start.IsPageAligned() && ar.End.IsPageAligned() -} - -// String implements fmt.Stringer.String. -func (ar AddrRange) String() string { - return fmt.Sprintf("[%#x, %#x)", ar.Start, ar.End) -} - -// PageRoundDown/Up are equivalent to Addr.RoundDown/Up, but without the -// potentially truncating conversion from uint64 to Addr. This is necessary -// because there is no way to define generic "PageRoundDown/Up" functions in Go. - -// PageRoundDown returns x rounded down to the nearest page boundary. -func PageRoundDown(x uint64) uint64 { - return x &^ (PageSize - 1) -} - -// PageRoundUp returns x rounded up to the nearest page boundary. -// ok is true iff rounding up did not wrap around. -func PageRoundUp(x uint64) (addr uint64, ok bool) { - addr = PageRoundDown(x + PageSize - 1) - ok = addr >= x - return -} |