unwind

package
v0.30.0 Latest Latest
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 Go to latest Published: Mar 4, 2024 License: Apache-2.0 Imports: 21 Imported by: 0

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Index

Constants

This section is empty.

Variables

View Source 
var (
	ErrNoFDEsFound            = errors.New("no FDEs found")
	ErrEhFrameSectionNotFound = errors.New("failed to find .eh_frame section")
	ErrNoRegisterFound        = errors.New("architecture not supported")
)
View Source 
var Plt1 = [...]byte{
	frame.DW_OP_breg7,
	frame.DW_OP_const1u,
	frame.DW_OP_breg16,
	frame.DW_OP_lit15,
	frame.DW_OP_and,
	frame.DW_OP_lit11,
	frame.DW_OP_ge,
	frame.DW_OP_lit3,
	frame.DW_OP_shl,
	frame.DW_OP_plus,
}

Plt1 is equivalent to: sp + 8 + ((((ip & 15) >= 11)) << 3.

View Source 
var Plt2 = [...]byte{
	frame.DW_OP_breg7,
	frame.DW_OP_const1u,
	frame.DW_OP_breg16,
	frame.DW_OP_lit15,
	frame.DW_OP_and,
	frame.DW_OP_lit10,
	frame.DW_OP_ge,
	frame.DW_OP_lit3,
	frame.DW_OP_shl,
	frame.DW_OP_plus,
}

Plt2 is quivalent to: sp + 8 + ((((ip & 15) >= 10)) << 3.

Functions

func ReadFDEs added in v0.13.0 

func ReadFDEs(path string) (frame.FrameDescriptionEntries, elf.Machine, error)

Types

type BpfCfaType added in v0.12.0 

type BpfCfaType uint8

type CompactUnwindTable added in v0.12.0 

type CompactUnwindTable []CompactUnwindTableRow

func BuildCompactUnwindTable added in v0.12.0 

func BuildCompactUnwindTable(fdes frame.FrameDescriptionEntries, arch elf.Machine) (CompactUnwindTable, error)

BuildCompactUnwindTable produces a compact unwind table for the given frame description entries.

func CompactUnwindTableRepresentation added in v0.12.0 

func CompactUnwindTableRepresentation(unwindTable UnwindTable, arch elf.Machine) (CompactUnwindTable, error)

compactUnwindTableRepresentation converts an unwind table to its compact table representation.

func GenerateCompactUnwindTable added in v0.24.0 

func GenerateCompactUnwindTable(fullExecutablePath string) (CompactUnwindTable, elf.Machine, error)

GenerateCompactUnwindTable produces the compact unwind table for a given executable.

func (CompactUnwindTable) Len added in v0.12.0 

func (t CompactUnwindTable) Len() int

func (CompactUnwindTable) Less added in v0.12.0 

func (t CompactUnwindTable) Less(i, j int) bool

func (CompactUnwindTable) RemoveRedundant added in v0.26.0 

func (t CompactUnwindTable) RemoveRedundant() CompactUnwindTable

RemoveRedundant removes redudant unwind rows in place.

func (CompactUnwindTable) Swap added in v0.12.0 

func (t CompactUnwindTable) Swap(i, j int)

type CompactUnwindTableRow added in v0.12.0 

type CompactUnwindTableRow struct {
	// contains filtered or unexported fields
}

CompactUnwindTableRows encodes unwind information using 2x 64 bit words. `lrOffset` is the link register for arm64; it is initialized to 0 for x86.

func (*CompactUnwindTableRow) CfaOffset added in v0.12.0 

func (cutr *CompactUnwindTableRow) CfaOffset() int16

func (*CompactUnwindTableRow) CfaType added in v0.12.0 

func (cutr *CompactUnwindTableRow) CfaType() uint8

func (*CompactUnwindTableRow) IsEndOfFDEMarker added in v0.13.0 

func (cutr *CompactUnwindTableRow) IsEndOfFDEMarker() bool

func (*CompactUnwindTableRow) IsRedundant added in v0.26.0 

func (cutr *CompactUnwindTableRow) IsRedundant(other *CompactUnwindTableRow) bool

func (*CompactUnwindTableRow) LrOffset added in v0.24.0 

func (cutr *CompactUnwindTableRow) LrOffset() int16

func (*CompactUnwindTableRow) Pc added in v0.12.0 

func (cutr *CompactUnwindTableRow) Pc() uint64

func (*CompactUnwindTableRow) RbpOffset added in v0.12.0 

func (cutr *CompactUnwindTableRow) RbpOffset() int16

func (*CompactUnwindTableRow) RbpType added in v0.12.0 

func (cutr *CompactUnwindTableRow) RbpType() uint8

func (*CompactUnwindTableRow) ToString added in v0.26.0 

func (cutr *CompactUnwindTableRow) ToString(showLr bool) string

type DWARFExpressionID added in v0.28.0 

type DWARFExpressionID int16
const (
	ExpressionUnknown DWARFExpressionID = iota
	ExpressionPlt1
	ExpressionPlt2
)

func ExpressionIdentifier added in v0.11.0 

func ExpressionIdentifier(expression []byte, arch elf.Machine) DWARFExpressionID

ExpressionIdentifier returns the identifier for recognized DWARF expressions.

type ExecutableMapping added in v0.12.0 

type ExecutableMapping struct {
	LoadAddr   uint64
	StartAddr  uint64
	EndAddr    uint64
	Executable string
	// contains filtered or unexported fields
}

ExecutableMapping represents an executable memory mapping.

func (*ExecutableMapping) IsJITDump added in v0.28.0 

func (pm *ExecutableMapping) IsJITDump() bool

IsJITDump returns whether the mapping looks like a jitdump0 file.

func (*ExecutableMapping) IsJITted added in v0.28.0 

func (pm *ExecutableMapping) IsJITted() bool

IsJITted returns whether an executable mapping is JITed or not. The detection is done by checking if the executable mapping is not backed by a file.

We don't check for the writeable flag as `mprotect(2)` may be called to make it r+w only.

func (*ExecutableMapping) IsMainObject added in v0.12.0 

func (pm *ExecutableMapping) IsMainObject() bool

IsMainObject returns whether this executable is the "main executable". which triggered the loading of all the other mappings.

We care about this because if Linux ASLR is enabled, we have to modify the loaded addresses for the main object.

func (*ExecutableMapping) IsNotFileBacked added in v0.12.0 

func (pm *ExecutableMapping) IsNotFileBacked() bool

IsNotFileBacked returns whether the mapping is not backed by a file, such as JIT or vDSO sections.

func (*ExecutableMapping) IsSpecial added in v0.12.0 

func (pm *ExecutableMapping) IsSpecial() bool

IsSpecial returns whether the file mapping is a "special" region, such as the mappings for vDSOs `[vdso]` and others.

func (*ExecutableMapping) String added in v0.12.0 

func (pm *ExecutableMapping) String() string

type ExecutableMappings added in v0.12.0 

type ExecutableMappings []*ExecutableMapping

func ListExecutableMappings added in v0.12.0 

func ListExecutableMappings(rawMappings []*procfs.ProcMap) ExecutableMappings

ExecutableMappings returns the executable memory mappings with the appropriate loaded base address set for non-JIT code.

The reason why we need to find the loaded base address is that ELF executables aren't typically loaded in one large executable section, but split in several mappings. For example, the .rodata section, as well as .eh_frame might go in sections without executable permissions, as they aren't needed.

Note: jitdump files are typically executable but are excluded from the results.

func (ExecutableMappings) HasJITted added in v0.28.0 

func (pm ExecutableMappings) HasJITted() bool

HasJITted returns if there's at least one JIT'ed mapping.

func (ExecutableMappings) Hash added in v0.15.0 

func (pm ExecutableMappings) Hash() (uint64, error)

Hash produces a summary of the executable mappings.

type FramePointerCache added in v0.13.0 

type FramePointerCache struct {
	// contains filtered or unexported fields
}

func NewHasFramePointersCache added in v0.13.0 

func NewHasFramePointersCache(logger log.Logger, reg prometheus.Registerer, cim *runtime.CompilerInfoManager) FramePointerCache

func (*FramePointerCache) HasFramePointers added in v0.13.0 

func (fpc *FramePointerCache) HasFramePointers(executable string) (bool, error)

type UnwindTable 

type UnwindTable []UnwindTableRow

func BuildUnwindTable added in v0.13.0 

func BuildUnwindTable(fdes frame.FrameDescriptionEntries) (UnwindTable, error)

func (UnwindTable) Len 

func (t UnwindTable) Len() int

func (UnwindTable) Less 

func (t UnwindTable) Less(i, j int) bool

func (UnwindTable) Swap 

func (t UnwindTable) Swap(i, j int)

type UnwindTableBuilder 

type UnwindTableBuilder struct {
	// contains filtered or unexported fields
}

func NewUnwindTableBuilder 

func NewUnwindTableBuilder(logger log.Logger) *UnwindTableBuilder

func (*UnwindTableBuilder) PrintTable 

func (ptb *UnwindTableBuilder) PrintTable(writer io.Writer, path string, compact bool, pc *uint64) error

PrintTable is a debugging helper that prints the unwinding table to the given io.Writer.

type UnwindTableRow 

type UnwindTableRow struct {
	// The address of the machine instruction.
	// Each row covers a range of machine instruction, from its address (Loc) to that of the row below.
	Loc uint64
	// CFA, the value of the stack pointer in the previous frame.
	CFA frame.DWRule
	// The value of the RBP register.
	RBP frame.DWRule
	// The value of the saved return address. This is not needed in x86_64 as it's part of the ABI but is necessary
	// in arm64.
	RA frame.DWRule
}

UnwindTableRow represents a single row in the unwind table. x86_64: rip (instruction pointer register), rsp (stack pointer register), rbp (base pointer/frame pointer register) aarch64: lr(link register), sp(stack pointer register), fp(frame pointer register)

Source Files

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