Method findProgramHeader

internal/binutils/binutils.go:537–573

findProgramHeader returns the program segment that matches the current mapping and the given address, or an error if it cannot find a unique program header.

(ef *elf.File, addr uint64)

// mapping and the given address, or an error if it cannot find a unique program
// header.
func (m *elfMapping) findProgramHeader(ef *elf.File, addr uint64) (*elf.ProgHeader, error) {
	// For user space executables, we try to find the actual program segment that
	// is associated with the given mapping. Skip this search if limit <= start.
	// We cannot use just a check on the start address of the mapping to tell if
	// it's a kernel / .ko module mapping, because with quipper address remapping
	// enabled, the address would be in the lower half of the address space.

	if m.kernelOffset != nil || m.start >= m.limit || m.limit >= (uint64(1)<<63) {
		// For the kernel, find the program segment that includes the .text section.
		return elfexec.FindTextProgHeader(ef), nil
	}

	// Fetch all the loadable segments.
	var phdrs []elf.ProgHeader
	for i := range ef.Progs {
		if ef.Progs[i].Type == elf.PT_LOAD {
			phdrs = append(phdrs, ef.Progs[i].ProgHeader)
		}
	}
	// Some ELF files don't contain any loadable program segments, e.g. .ko
	// kernel modules. It's not an error to have no header in such cases.
	if len(phdrs) == 0 {
		return nil, nil
	}
	// Get all program headers associated with the mapping.
	headers := elfexec.ProgramHeadersForMapping(phdrs, m.offset, m.limit-m.start)
	if len(headers) == 0 {
		return nil, errors.New("no program header matches mapping info")
	}
	if len(headers) == 1 {
		return headers[0], nil
	}

	// Use the file offset corresponding to the address to symbolize, to narrow
	// down the header.
	return elfexec.HeaderForFileOffset(headers, addr-m.start+m.offset)
}

// file implements the binutils.ObjFile interface.
type file struct {