diff options
Diffstat (limited to 'vendor/github.com/cilium/ebpf/asm/load_store.go')
-rw-r--r-- | vendor/github.com/cilium/ebpf/asm/load_store.go | 204 |
1 files changed, 204 insertions, 0 deletions
diff --git a/vendor/github.com/cilium/ebpf/asm/load_store.go b/vendor/github.com/cilium/ebpf/asm/load_store.go new file mode 100644 index 000000000..2d0ec648e --- /dev/null +++ b/vendor/github.com/cilium/ebpf/asm/load_store.go @@ -0,0 +1,204 @@ +package asm + +//go:generate stringer -output load_store_string.go -type=Mode,Size + +// Mode for load and store operations +// +// msb lsb +// +---+--+---+ +// |MDE|sz|cls| +// +---+--+---+ +type Mode uint8 + +const modeMask OpCode = 0xe0 + +const ( + // InvalidMode is returned by getters when invoked + // on non load / store OpCodes + InvalidMode Mode = 0xff + // ImmMode - immediate value + ImmMode Mode = 0x00 + // AbsMode - immediate value + offset + AbsMode Mode = 0x20 + // IndMode - indirect (imm+src) + IndMode Mode = 0x40 + // MemMode - load from memory + MemMode Mode = 0x60 + // XAddMode - add atomically across processors. + XAddMode Mode = 0xc0 +) + +// Size of load and store operations +// +// msb lsb +// +---+--+---+ +// |mde|SZ|cls| +// +---+--+---+ +type Size uint8 + +const sizeMask OpCode = 0x18 + +const ( + // InvalidSize is returned by getters when invoked + // on non load / store OpCodes + InvalidSize Size = 0xff + // DWord - double word; 64 bits + DWord Size = 0x18 + // Word - word; 32 bits + Word Size = 0x00 + // Half - half-word; 16 bits + Half Size = 0x08 + // Byte - byte; 8 bits + Byte Size = 0x10 +) + +// Sizeof returns the size in bytes. +func (s Size) Sizeof() int { + switch s { + case DWord: + return 8 + case Word: + return 4 + case Half: + return 2 + case Byte: + return 1 + default: + return -1 + } +} + +// LoadMemOp returns the OpCode to load a value of given size from memory. +func LoadMemOp(size Size) OpCode { + return OpCode(LdXClass).SetMode(MemMode).SetSize(size) +} + +// LoadMem emits `dst = *(size *)(src + offset)`. +func LoadMem(dst, src Register, offset int16, size Size) Instruction { + return Instruction{ + OpCode: LoadMemOp(size), + Dst: dst, + Src: src, + Offset: offset, + } +} + +// LoadImmOp returns the OpCode to load an immediate of given size. +// +// As of kernel 4.20, only DWord size is accepted. +func LoadImmOp(size Size) OpCode { + return OpCode(LdClass).SetMode(ImmMode).SetSize(size) +} + +// LoadImm emits `dst = (size)value`. +// +// As of kernel 4.20, only DWord size is accepted. +func LoadImm(dst Register, value int64, size Size) Instruction { + return Instruction{ + OpCode: LoadImmOp(size), + Dst: dst, + Constant: value, + } +} + +// LoadMapPtr stores a pointer to a map in dst. +func LoadMapPtr(dst Register, fd int) Instruction { + if fd < 0 { + return Instruction{OpCode: InvalidOpCode} + } + + return Instruction{ + OpCode: LoadImmOp(DWord), + Dst: dst, + Src: PseudoMapFD, + Constant: int64(fd), + } +} + +// LoadMapValue stores a pointer to the value at a certain offset of a map. +func LoadMapValue(dst Register, fd int, offset uint32) Instruction { + if fd < 0 { + return Instruction{OpCode: InvalidOpCode} + } + + fdAndOffset := (uint64(offset) << 32) | uint64(uint32(fd)) + return Instruction{ + OpCode: LoadImmOp(DWord), + Dst: dst, + Src: PseudoMapValue, + Constant: int64(fdAndOffset), + } +} + +// LoadIndOp returns the OpCode for loading a value of given size from an sk_buff. +func LoadIndOp(size Size) OpCode { + return OpCode(LdClass).SetMode(IndMode).SetSize(size) +} + +// LoadInd emits `dst = ntoh(*(size *)(((sk_buff *)R6)->data + src + offset))`. +func LoadInd(dst, src Register, offset int32, size Size) Instruction { + return Instruction{ + OpCode: LoadIndOp(size), + Dst: dst, + Src: src, + Constant: int64(offset), + } +} + +// LoadAbsOp returns the OpCode for loading a value of given size from an sk_buff. +func LoadAbsOp(size Size) OpCode { + return OpCode(LdClass).SetMode(AbsMode).SetSize(size) +} + +// LoadAbs emits `r0 = ntoh(*(size *)(((sk_buff *)R6)->data + offset))`. +func LoadAbs(offset int32, size Size) Instruction { + return Instruction{ + OpCode: LoadAbsOp(size), + Dst: R0, + Constant: int64(offset), + } +} + +// StoreMemOp returns the OpCode for storing a register of given size in memory. +func StoreMemOp(size Size) OpCode { + return OpCode(StXClass).SetMode(MemMode).SetSize(size) +} + +// StoreMem emits `*(size *)(dst + offset) = src` +func StoreMem(dst Register, offset int16, src Register, size Size) Instruction { + return Instruction{ + OpCode: StoreMemOp(size), + Dst: dst, + Src: src, + Offset: offset, + } +} + +// StoreImmOp returns the OpCode for storing an immediate of given size in memory. +func StoreImmOp(size Size) OpCode { + return OpCode(StClass).SetMode(MemMode).SetSize(size) +} + +// StoreImm emits `*(size *)(dst + offset) = value`. +func StoreImm(dst Register, offset int16, value int64, size Size) Instruction { + return Instruction{ + OpCode: StoreImmOp(size), + Dst: dst, + Offset: offset, + Constant: value, + } +} + +// StoreXAddOp returns the OpCode to atomically add a register to a value in memory. +func StoreXAddOp(size Size) OpCode { + return OpCode(StXClass).SetMode(XAddMode).SetSize(size) +} + +// StoreXAdd atomically adds src to *dst. +func StoreXAdd(dst, src Register, size Size) Instruction { + return Instruction{ + OpCode: StoreXAddOp(size), + Dst: dst, + Src: src, + } +} |