+"""
+This python script adds a new gdb command, "dump-guest-memory". It
+should be loaded with "source dump-guest-memory.py" at the (gdb)
+prompt.
+
+Copyright (C) 2013, Red Hat, Inc.
+
+Authors:
+ Laszlo Ersek <lersek@redhat.com>
+ Janosch Frank <frankja@linux.vnet.ibm.com>
+
+This work is licensed under the terms of the GNU GPL, version 2 or later. See
+the COPYING file in the top-level directory.
+"""
+
+import ctypes
+
+UINTPTR_T = gdb.lookup_type("uintptr_t")
+
+TARGET_PAGE_SIZE = 0x1000
+TARGET_PAGE_MASK = 0xFFFFFFFFFFFFF000
+
+# Special value for e_phnum. This indicates that the real number of
+# program headers is too large to fit into e_phnum. Instead the real
+# value is in the field sh_info of section 0.
+PN_XNUM = 0xFFFF
+
+EV_CURRENT = 1
+
+ELFCLASS32 = 1
+ELFCLASS64 = 2
+
+ELFDATA2LSB = 1
+ELFDATA2MSB = 2
+
+ET_CORE = 4
+
+PT_LOAD = 1
+PT_NOTE = 4
+
+EM_386 = 3
+EM_PPC = 20
+EM_PPC64 = 21
+EM_S390 = 22
+EM_AARCH = 183
+EM_X86_64 = 62
+
+class ELF(object):
+ """Representation of a ELF file."""
+
+ def __init__(self, arch):
+ self.ehdr = None
+ self.notes = []
+ self.segments = []
+ self.notes_size = 0
+ self.endianess = None
+ self.elfclass = ELFCLASS64
+
+ if arch == 'aarch64-le':
+ self.endianess = ELFDATA2LSB
+ self.elfclass = ELFCLASS64
+ self.ehdr = get_arch_ehdr(self.endianess, self.elfclass)
+ self.ehdr.e_machine = EM_AARCH
+
+ elif arch == 'aarch64-be':
+ self.endianess = ELFDATA2MSB
+ self.ehdr = get_arch_ehdr(self.endianess, self.elfclass)
+ self.ehdr.e_machine = EM_AARCH
+
+ elif arch == 'X86_64':
+ self.endianess = ELFDATA2LSB
+ self.ehdr = get_arch_ehdr(self.endianess, self.elfclass)
+ self.ehdr.e_machine = EM_X86_64
+
+ elif arch == '386':
+ self.endianess = ELFDATA2LSB
+ self.elfclass = ELFCLASS32
+ self.ehdr = get_arch_ehdr(self.endianess, self.elfclass)
+ self.ehdr.e_machine = EM_386
+
+ elif arch == 's390':
+ self.endianess = ELFDATA2MSB
+ self.ehdr = get_arch_ehdr(self.endianess, self.elfclass)
+ self.ehdr.e_machine = EM_S390
+
+ elif arch == 'ppc64-le':
+ self.endianess = ELFDATA2LSB
+ self.ehdr = get_arch_ehdr(self.endianess, self.elfclass)
+ self.ehdr.e_machine = EM_PPC64
+
+ elif arch == 'ppc64-be':
+ self.endianess = ELFDATA2MSB
+ self.ehdr = get_arch_ehdr(self.endianess, self.elfclass)
+ self.ehdr.e_machine = EM_PPC64
+
+ else:
+ raise gdb.GdbError("No valid arch type specified.\n"
+ "Currently supported types:\n"
+ "aarch64-be, aarch64-le, X86_64, 386, s390, "
+ "ppc64-be, ppc64-le")
+
+ self.add_segment(PT_NOTE, 0, 0)
+
+ def add_note(self, n_name, n_desc, n_type):
+ """Adds a note to the ELF."""
+
+ note = get_arch_note(self.endianess, len(n_name), len(n_desc))
+ note.n_namesz = len(n_name) + 1
+ note.n_descsz = len(n_desc)
+ note.n_name = n_name.encode()
+ note.n_type = n_type
+
+ # Desc needs to be 4 byte aligned (although the 64bit spec
+ # specifies 8 byte). When defining n_desc as uint32 it will be
+ # automatically aligned but we need the memmove to copy the
+ # string into it.
+ ctypes.memmove(note.n_desc, n_desc.encode(), len(n_desc))
+
+ self.notes.append(note)
+ self.segments[0].p_filesz += ctypes.sizeof(note)
+ self.segments[0].p_memsz += ctypes.sizeof(note)
+
+ def add_segment(self, p_type, p_paddr, p_size):
+ """Adds a segment to the elf."""
+
+ phdr = get_arch_phdr(self.endianess, self.elfclass)
+ phdr.p_type = p_type
+ phdr.p_paddr = p_paddr
+ phdr.p_filesz = p_size
+ phdr.p_memsz = p_size
+ self.segments.append(phdr)
+ self.ehdr.e_phnum += 1
+
+ def to_file(self, elf_file):
+ """Writes all ELF structures to the the passed file.
+
+ Structure:
+ Ehdr
+ Segment 0:PT_NOTE
+ Segment 1:PT_LOAD
+ Segment N:PT_LOAD
+ Note 0..N
+ Dump contents
+ """
+ elf_file.write(self.ehdr)
+ off = ctypes.sizeof(self.ehdr) + \
+ len(self.segments) * ctypes.sizeof(self.segments[0])
+
+ for phdr in self.segments:
+ phdr.p_offset = off
+ elf_file.write(phdr)
+ off += phdr.p_filesz
+
+ for note in self.notes:
+ elf_file.write(note)
+
+
+def get_arch_note(endianess, len_name, len_desc):
+ """Returns a Note class with the specified endianess."""
+
+ if endianess == ELFDATA2LSB:
+ superclass = ctypes.LittleEndianStructure
+ else:
+ superclass = ctypes.BigEndianStructure
+
+ len_name = len_name + 1
+
+ class Note(superclass):
+ """Represents an ELF note, includes the content."""
+
+ _fields_ = [("n_namesz", ctypes.c_uint32),
+ ("n_descsz", ctypes.c_uint32),
+ ("n_type", ctypes.c_uint32),
+ ("n_name", ctypes.c_char * len_name),
+ ("n_desc", ctypes.c_uint32 * ((len_desc + 3) // 4))]
+ return Note()
+
+
+class Ident(ctypes.Structure):
+ """Represents the ELF ident array in the ehdr structure."""
+
+ _fields_ = [('ei_mag0', ctypes.c_ubyte),
+ ('ei_mag1', ctypes.c_ubyte),
+ ('ei_mag2', ctypes.c_ubyte),
+ ('ei_mag3', ctypes.c_ubyte),
+ ('ei_class', ctypes.c_ubyte),
+ ('ei_data', ctypes.c_ubyte),
+ ('ei_version', ctypes.c_ubyte),
+ ('ei_osabi', ctypes.c_ubyte),
+ ('ei_abiversion', ctypes.c_ubyte),
+ ('ei_pad', ctypes.c_ubyte * 7)]
+
+ def __init__(self, endianess, elfclass):
+ self.ei_mag0 = 0x7F
+ self.ei_mag1 = ord('E')
+ self.ei_mag2 = ord('L')
+ self.ei_mag3 = ord('F')
+ self.ei_class = elfclass
+ self.ei_data = endianess
+ self.ei_version = EV_CURRENT
+
+
+def get_arch_ehdr(endianess, elfclass):
+ """Returns a EHDR64 class with the specified endianess."""
+
+ if endianess == ELFDATA2LSB:
+ superclass = ctypes.LittleEndianStructure
+ else:
+ superclass = ctypes.BigEndianStructure
+
+ class EHDR64(superclass):
+ """Represents the 64 bit ELF header struct."""
+
+ _fields_ = [('e_ident', Ident),
+ ('e_type', ctypes.c_uint16),
+ ('e_machine', ctypes.c_uint16),
+ ('e_version', ctypes.c_uint32),
+ ('e_entry', ctypes.c_uint64),
+ ('e_phoff', ctypes.c_uint64),
+ ('e_shoff', ctypes.c_uint64),
+ ('e_flags', ctypes.c_uint32),
+ ('e_ehsize', ctypes.c_uint16),
+ ('e_phentsize', ctypes.c_uint16),
+ ('e_phnum', ctypes.c_uint16),
+ ('e_shentsize', ctypes.c_uint16),
+ ('e_shnum', ctypes.c_uint16),
+ ('e_shstrndx', ctypes.c_uint16)]
+
+ def __init__(self):
+ super(superclass, self).__init__()
+ self.e_ident = Ident(endianess, elfclass)
+ self.e_type = ET_CORE
+ self.e_version = EV_CURRENT
+ self.e_ehsize = ctypes.sizeof(self)
+ self.e_phoff = ctypes.sizeof(self)
+ self.e_phentsize = ctypes.sizeof(get_arch_phdr(endianess, elfclass))
+ self.e_phnum = 0
+
+
+ class EHDR32(superclass):
+ """Represents the 32 bit ELF header struct."""
+
+ _fields_ = [('e_ident', Ident),
+ ('e_type', ctypes.c_uint16),
+ ('e_machine', ctypes.c_uint16),
+ ('e_version', ctypes.c_uint32),
+ ('e_entry', ctypes.c_uint32),
+ ('e_phoff', ctypes.c_uint32),
+ ('e_shoff', ctypes.c_uint32),
+ ('e_flags', ctypes.c_uint32),
+ ('e_ehsize', ctypes.c_uint16),
+ ('e_phentsize', ctypes.c_uint16),
+ ('e_phnum', ctypes.c_uint16),
+ ('e_shentsize', ctypes.c_uint16),
+ ('e_shnum', ctypes.c_uint16),
+ ('e_shstrndx', ctypes.c_uint16)]
+
+ def __init__(self):
+ super(superclass, self).__init__()
+ self.e_ident = Ident(endianess, elfclass)
+ self.e_type = ET_CORE
+ self.e_version = EV_CURRENT
+ self.e_ehsize = ctypes.sizeof(self)
+ self.e_phoff = ctypes.sizeof(self)
+ self.e_phentsize = ctypes.sizeof(get_arch_phdr(endianess, elfclass))
+ self.e_phnum = 0
+
+ # End get_arch_ehdr
+ if elfclass == ELFCLASS64:
+ return EHDR64()
+ else:
+ return EHDR32()
+
+
+def get_arch_phdr(endianess, elfclass):
+ """Returns a 32 or 64 bit PHDR class with the specified endianess."""
+
+ if endianess == ELFDATA2LSB:
+ superclass = ctypes.LittleEndianStructure
+ else:
+ superclass = ctypes.BigEndianStructure
+
+ class PHDR64(superclass):
+ """Represents the 64 bit ELF program header struct."""
+
+ _fields_ = [('p_type', ctypes.c_uint32),
+ ('p_flags', ctypes.c_uint32),
+ ('p_offset', ctypes.c_uint64),
+ ('p_vaddr', ctypes.c_uint64),
+ ('p_paddr', ctypes.c_uint64),
+ ('p_filesz', ctypes.c_uint64),
+ ('p_memsz', ctypes.c_uint64),
+ ('p_align', ctypes.c_uint64)]
+
+ class PHDR32(superclass):
+ """Represents the 32 bit ELF program header struct."""
+
+ _fields_ = [('p_type', ctypes.c_uint32),
+ ('p_offset', ctypes.c_uint32),
+ ('p_vaddr', ctypes.c_uint32),
+ ('p_paddr', ctypes.c_uint32),
+ ('p_filesz', ctypes.c_uint32),
+ ('p_memsz', ctypes.c_uint32),
+ ('p_flags', ctypes.c_uint32),
+ ('p_align', ctypes.c_uint32)]
+
+ # End get_arch_phdr
+ if elfclass == ELFCLASS64:
+ return PHDR64()
+ else:
+ return PHDR32()
+
+
+def int128_get64(val):
+ """Returns low 64bit part of Int128 struct."""
+
+ assert val["hi"] == 0
+ return val["lo"]
+
+
+def qlist_foreach(head, field_str):
+ """Generator for qlists."""
+
+ var_p = head["lh_first"]
+ while var_p != 0:
+ var = var_p.dereference()
+ var_p = var[field_str]["le_next"]
+ yield var
+
+
+def qemu_get_ram_block(ram_addr):
+ """Returns the RAMBlock struct to which the given address belongs."""
+
+ ram_blocks = gdb.parse_and_eval("ram_list.blocks")
+
+ for block in qlist_foreach(ram_blocks, "next"):
+ if (ram_addr - block["offset"]) < block["used_length"]:
+ return block
+
+ raise gdb.GdbError("Bad ram offset %x" % ram_addr)
+
+
+def qemu_get_ram_ptr(ram_addr):
+ """Returns qemu vaddr for given guest physical address."""
+
+ block = qemu_get_ram_block(ram_addr)
+ return block["host"] + (ram_addr - block["offset"])
+
+
+def memory_region_get_ram_ptr(memory_region):
+ if memory_region["alias"] != 0:
+ return (memory_region_get_ram_ptr(memory_region["alias"].dereference())
+ + memory_region["alias_offset"])
+
+ return qemu_get_ram_ptr(memory_region["ram_block"]["offset"])
+
+
+def get_guest_phys_blocks():
+ """Returns a list of ram blocks.
+
+ Each block entry contains:
+ 'target_start': guest block phys start address
+ 'target_end': guest block phys end address
+ 'host_addr': qemu vaddr of the block's start
+ """
+
+ guest_phys_blocks = []
+
+ print("guest RAM blocks:")
+ print("target_start target_end host_addr message "
+ "count")
+ print("---------------- ---------------- ---------------- ------- "
+ "-----")
+
+ current_map_p = gdb.parse_and_eval("address_space_memory.current_map")
+ current_map = current_map_p.dereference()
+
+ # Conversion to int is needed for python 3
+ # compatibility. Otherwise range doesn't cast the value itself and
+ # breaks.
+ for cur in range(int(current_map["nr"])):
+ flat_range = (current_map["ranges"] + cur).dereference()
+ memory_region = flat_range["mr"].dereference()
+
+ # we only care about RAM
+ if not memory_region["ram"]:
+ continue
+
+ section_size = int128_get64(flat_range["addr"]["size"])
+ target_start = int128_get64(flat_range["addr"]["start"])
+ target_end = target_start + section_size
+ host_addr = (memory_region_get_ram_ptr(memory_region)
+ + flat_range["offset_in_region"])
+ predecessor = None
+
+ # find continuity in guest physical address space
+ if len(guest_phys_blocks) > 0:
+ predecessor = guest_phys_blocks[-1]
+ predecessor_size = (predecessor["target_end"] -
+ predecessor["target_start"])
+
+ # the memory API guarantees monotonically increasing
+ # traversal
+ assert predecessor["target_end"] <= target_start
+
+ # we want continuity in both guest-physical and
+ # host-virtual memory
+ if (predecessor["target_end"] < target_start or
+ predecessor["host_addr"] + predecessor_size != host_addr):
+ predecessor = None
+
+ if predecessor is None:
+ # isolated mapping, add it to the list
+ guest_phys_blocks.append({"target_start": target_start,
+ "target_end": target_end,
+ "host_addr": host_addr})
+ message = "added"
+ else:
+ # expand predecessor until @target_end; predecessor's
+ # start doesn't change
+ predecessor["target_end"] = target_end
+ message = "joined"
+
+ print("%016x %016x %016x %-7s %5u" %
+ (target_start, target_end, host_addr.cast(UINTPTR_T),
+ message, len(guest_phys_blocks)))
+
+ return guest_phys_blocks
+
+
Code Review / kvmfornfv.git / blobdiff