Initial commit: Linux kernel 4.19 for Unplugged OS

scripts/gdb/Makefile

@@ -0,0 +1 @@
+subdir-y := linux

scripts/gdb/linux/Makefile

@@ -0,0 +1,24 @@
+# SPDX-License-Identifier: GPL-2.0
+always := gdb-scripts
+
+SRCTREE := $(abspath $(srctree))
+
+$(obj)/gdb-scripts:
+ifneq ($(KBUILD_SRC),)
+	$(Q)ln -fsn $(SRCTREE)/$(obj)/*.py $(objtree)/$(obj)
+endif
+	@:
+
+quiet_cmd_gen_constants_py = GEN     $@
+      cmd_gen_constants_py = \
+	$(CPP) -E -x c -P $(c_flags) $< > $@ ;\
+	sed -i '1,/<!-- end-c-headers -->/d;' $@
+
+targets += constants.py
+$(obj)/constants.py: $(SRCTREE)/$(obj)/constants.py.in FORCE
+	$(call if_changed_dep,gen_constants_py)
+
+build_constants_py: $(obj)/constants.py
+	@:
+
+clean-files := *.pyc *.pyo $(if $(KBUILD_SRC),*.py) $(obj)/constants.py

scripts/gdb/linux/__init__.py

@@ -0,0 +1 @@
+# nothing to do for the initialization of this package

scripts/gdb/linux/constants.py.in

@@ -0,0 +1,59 @@
+/*
+ * gdb helper commands and functions for Linux kernel debugging
+ *
+ *  Kernel constants derived from include files.
+ *
+ * Copyright (c) 2016 Linaro Ltd
+ *
+ * Authors:
+ *  Kieran Bingham <kieran.bingham@linaro.org>
+ *
+ * This work is licensed under the terms of the GNU GPL version 2.
+ *
+ */
+
+#include <linux/fs.h>
+#include <linux/mount.h>
+#include <linux/of_fdt.h>
+
+/* We need to stringify expanded macros so that they can be parsed */
+
+#define STRING(x) #x
+#define XSTRING(x) STRING(x)
+
+#define LX_VALUE(x) LX_##x = x
+#define LX_GDBPARSED(x) LX_##x = gdb.parse_and_eval(XSTRING(x))
+
+/*
+ * IS_ENABLED generates (a || b) which is not compatible with python
+ * We can only switch on configuration items we know are available
+ * Therefore - IS_BUILTIN() is more appropriate
+ */
+#define LX_CONFIG(x) LX_##x = IS_BUILTIN(x)
+
+/* The build system will take care of deleting everything above this marker */
+<!-- end-c-headers -->
+
+import gdb
+
+/* linux/fs.h */
+LX_VALUE(MS_RDONLY)
+LX_VALUE(MS_SYNCHRONOUS)
+LX_VALUE(MS_MANDLOCK)
+LX_VALUE(MS_DIRSYNC)
+LX_VALUE(MS_NOATIME)
+LX_VALUE(MS_NODIRATIME)
+
+/* linux/mount.h */
+LX_VALUE(MNT_NOSUID)
+LX_VALUE(MNT_NODEV)
+LX_VALUE(MNT_NOEXEC)
+LX_VALUE(MNT_NOATIME)
+LX_VALUE(MNT_NODIRATIME)
+LX_VALUE(MNT_RELATIME)
+
+/* linux/of_fdt.h> */
+LX_VALUE(OF_DT_HEADER)
+
+/* Kernel Configs */
+LX_CONFIG(CONFIG_OF)

scripts/gdb/linux/cpus.py

@@ -0,0 +1,173 @@
+#
+# gdb helper commands and functions for Linux kernel debugging
+#
+#  per-cpu tools
+#
+# Copyright (c) Siemens AG, 2011-2013
+#
+# Authors:
+#  Jan Kiszka <jan.kiszka@siemens.com>
+#
+# This work is licensed under the terms of the GNU GPL version 2.
+#
+
+import gdb
+
+from linux import tasks, utils
+
+
+MAX_CPUS = 4096
+
+
+def get_current_cpu():
+    if utils.get_gdbserver_type() == utils.GDBSERVER_QEMU:
+        return gdb.selected_thread().num - 1
+    elif utils.get_gdbserver_type() == utils.GDBSERVER_KGDB:
+        tid = gdb.selected_thread().ptid[2]
+        if tid > (0x100000000 - MAX_CPUS - 2):
+            return 0x100000000 - tid - 2
+        else:
+            return tasks.get_thread_info(tasks.get_task_by_pid(tid))['cpu']
+    else:
+        raise gdb.GdbError("Sorry, obtaining the current CPU is not yet "
+                           "supported with this gdb server.")
+
+
+def per_cpu(var_ptr, cpu):
+    if cpu == -1:
+        cpu = get_current_cpu()
+    if utils.is_target_arch("sparc:v9"):
+        offset = gdb.parse_and_eval(
+            "trap_block[{0}].__per_cpu_base".format(str(cpu)))
+    else:
+        try:
+            offset = gdb.parse_and_eval(
+                "__per_cpu_offset[{0}]".format(str(cpu)))
+        except gdb.error:
+            # !CONFIG_SMP case
+            offset = 0
+    pointer = var_ptr.cast(utils.get_long_type()) + offset
+    return pointer.cast(var_ptr.type).dereference()
+
+
+cpu_mask = {}
+
+
+def cpu_mask_invalidate(event):
+    global cpu_mask
+    cpu_mask = {}
+    gdb.events.stop.disconnect(cpu_mask_invalidate)
+    if hasattr(gdb.events, 'new_objfile'):
+        gdb.events.new_objfile.disconnect(cpu_mask_invalidate)
+
+
+def cpu_list(mask_name):
+    global cpu_mask
+    mask = None
+    if mask_name in cpu_mask:
+        mask = cpu_mask[mask_name]
+    if mask is None:
+        mask = gdb.parse_and_eval(mask_name + ".bits")
+        if hasattr(gdb, 'events'):
+            cpu_mask[mask_name] = mask
+            gdb.events.stop.connect(cpu_mask_invalidate)
+            if hasattr(gdb.events, 'new_objfile'):
+                gdb.events.new_objfile.connect(cpu_mask_invalidate)
+    bits_per_entry = mask[0].type.sizeof * 8
+    num_entries = mask.type.sizeof * 8 / bits_per_entry
+    entry = -1
+    bits = 0
+
+    while True:
+        while bits == 0:
+            entry += 1
+            if entry == num_entries:
+                return
+            bits = mask[entry]
+            if bits != 0:
+                bit = 0
+                break
+
+        while bits & 1 == 0:
+            bits >>= 1
+            bit += 1
+
+        cpu = entry * bits_per_entry + bit
+
+        bits >>= 1
+        bit += 1
+
+        yield int(cpu)
+
+
+def each_online_cpu():
+    for cpu in cpu_list("__cpu_online_mask"):
+        yield cpu
+
+
+def each_present_cpu():
+    for cpu in cpu_list("__cpu_present_mask"):
+        yield cpu
+
+
+def each_possible_cpu():
+    for cpu in cpu_list("__cpu_possible_mask"):
+        yield cpu
+
+
+def each_active_cpu():
+    for cpu in cpu_list("__cpu_active_mask"):
+        yield cpu
+
+
+class LxCpus(gdb.Command):
+    """List CPU status arrays
+
+Displays the known state of each CPU based on the kernel masks
+and can help identify the state of hotplugged CPUs"""
+
+    def __init__(self):
+        super(LxCpus, self).__init__("lx-cpus", gdb.COMMAND_DATA)
+
+    def invoke(self, arg, from_tty):
+        gdb.write("Possible CPUs : {}\n".format(list(each_possible_cpu())))
+        gdb.write("Present CPUs  : {}\n".format(list(each_present_cpu())))
+        gdb.write("Online CPUs   : {}\n".format(list(each_online_cpu())))
+        gdb.write("Active CPUs   : {}\n".format(list(each_active_cpu())))
+
+LxCpus()
+
+
+class PerCpu(gdb.Function):
+    """Return per-cpu variable.
+
+$lx_per_cpu("VAR"[, CPU]): Return the per-cpu variable called VAR for the
+given CPU number. If CPU is omitted, the CPU of the current context is used.
+Note that VAR has to be quoted as string."""
+
+    def __init__(self):
+        super(PerCpu, self).__init__("lx_per_cpu")
+
+    def invoke(self, var_name, cpu=-1):
+        var_ptr = gdb.parse_and_eval("&" + var_name.string())
+        return per_cpu(var_ptr, cpu)
+
+
+PerCpu()
+
+
+class LxCurrentFunc(gdb.Function):
+    """Return current task.
+
+$lx_current([CPU]): Return the per-cpu task variable for the given CPU
+number. If CPU is omitted, the CPU of the current context is used."""
+
+    def __init__(self):
+        super(LxCurrentFunc, self).__init__("lx_current")
+
+    def invoke(self, cpu=-1):
+        var_ptr = gdb.parse_and_eval("&current_task")
+        return per_cpu(var_ptr, cpu).dereference()
+
+
+LxCurrentFunc()

scripts/gdb/linux/dmesg.py

@@ -0,0 +1,73 @@
+#
+# gdb helper commands and functions for Linux kernel debugging
+#
+#  kernel log buffer dump
+#
+# Copyright (c) Siemens AG, 2011, 2012
+#
+# Authors:
+#  Jan Kiszka <jan.kiszka@siemens.com>
+#
+# This work is licensed under the terms of the GNU GPL version 2.
+#
+
+import gdb
+import sys
+
+from linux import utils
+
+
+class LxDmesg(gdb.Command):
+    """Print Linux kernel log buffer."""
+
+    def __init__(self):
+        super(LxDmesg, self).__init__("lx-dmesg", gdb.COMMAND_DATA)
+
+    def invoke(self, arg, from_tty):
+        log_buf_addr = int(str(gdb.parse_and_eval(
+            "(void *)'printk.c'::log_buf")).split()[0], 16)
+        log_first_idx = int(gdb.parse_and_eval("'printk.c'::log_first_idx"))
+        log_next_idx = int(gdb.parse_and_eval("'printk.c'::log_next_idx"))
+        log_buf_len = int(gdb.parse_and_eval("'printk.c'::log_buf_len"))
+
+        inf = gdb.inferiors()[0]
+        start = log_buf_addr + log_first_idx
+        if log_first_idx < log_next_idx:
+            log_buf_2nd_half = -1
+            length = log_next_idx - log_first_idx
+            log_buf = utils.read_memoryview(inf, start, length).tobytes()
+        else:
+            log_buf_2nd_half = log_buf_len - log_first_idx
+            a = utils.read_memoryview(inf, start, log_buf_2nd_half)
+            b = utils.read_memoryview(inf, log_buf_addr, log_next_idx)
+            log_buf = a.tobytes() + b.tobytes()
+
+        pos = 0
+        while pos < log_buf.__len__():
+            length = utils.read_u16(log_buf[pos + 8:pos + 10])
+            if length == 0:
+                if log_buf_2nd_half == -1:
+                    gdb.write("Corrupted log buffer!\n")
+                    break
+                pos = log_buf_2nd_half
+                continue
+
+            text_len = utils.read_u16(log_buf[pos + 10:pos + 12])
+            text = log_buf[pos + 16:pos + 16 + text_len].decode(
+                encoding='utf8', errors='replace')
+            time_stamp = utils.read_u64(log_buf[pos:pos + 8])
+
+            for line in text.splitlines():
+                msg = u"[{time:12.6f}] {line}\n".format(
+                    time=time_stamp / 1000000000.0,
+                    line=line)
+                # With python2 gdb.write will attempt to convert unicode to
+                # ascii and might fail so pass an utf8-encoded str instead.
+                if sys.hexversion < 0x03000000:
+                    msg = msg.encode(encoding='utf8', errors='replace')
+                gdb.write(msg)
+
+            pos += length
+
+
+LxDmesg()

scripts/gdb/linux/lists.py

@@ -0,0 +1,113 @@
+#
+# gdb helper commands and functions for Linux kernel debugging
+#
+#  list tools
+#
+# Copyright (c) Thiebaud Weksteen, 2015
+#
+# Authors:
+#  Thiebaud Weksteen <thiebaud@weksteen.fr>
+#
+# This work is licensed under the terms of the GNU GPL version 2.
+#
+
+import gdb
+
+from linux import utils
+
+list_head = utils.CachedType("struct list_head")
+
+
+def list_for_each(head):
+    if head.type == list_head.get_type().pointer():
+        head = head.dereference()
+    elif head.type != list_head.get_type():
+        raise gdb.GdbError("Must be struct list_head not {}"
+                           .format(head.type))
+
+    node = head['next'].dereference()
+    while node.address != head.address:
+        yield node.address
+        node = node['next'].dereference()
+
+
+def list_for_each_entry(head, gdbtype, member):
+    for node in list_for_each(head):
+        if node.type != list_head.get_type().pointer():
+            raise TypeError("Type {} found. Expected struct list_head *."
+                            .format(node.type))
+        yield utils.container_of(node, gdbtype, member)
+
+
+def list_check(head):
+    nb = 0
+    if (head.type == list_head.get_type().pointer()):
+        head = head.dereference()
+    elif (head.type != list_head.get_type()):
+        raise gdb.GdbError('argument must be of type (struct list_head [*])')
+    c = head
+    try:
+        gdb.write("Starting with: {}\n".format(c))
+    except gdb.MemoryError:
+        gdb.write('head is not accessible\n')
+        return
+    while True:
+        p = c['prev'].dereference()
+        n = c['next'].dereference()
+        try:
+            if p['next'] != c.address:
+                gdb.write('prev.next != current: '
+                          'current@{current_addr}={current} '
+                          'prev@{p_addr}={p}\n'.format(
+                              current_addr=c.address,
+                              current=c,
+                              p_addr=p.address,
+                              p=p,
+                          ))
+                return
+        except gdb.MemoryError:
+            gdb.write('prev is not accessible: '
+                      'current@{current_addr}={current}\n'.format(
+                          current_addr=c.address,
+                          current=c
+                      ))
+            return
+        try:
+            if n['prev'] != c.address:
+                gdb.write('next.prev != current: '
+                          'current@{current_addr}={current} '
+                          'next@{n_addr}={n}\n'.format(
+                              current_addr=c.address,
+                              current=c,
+                              n_addr=n.address,
+                              n=n,
+                          ))
+                return
+        except gdb.MemoryError:
+            gdb.write('next is not accessible: '
+                      'current@{current_addr}={current}\n'.format(
+                          current_addr=c.address,
+                          current=c
+                      ))
+            return
+        c = n
+        nb += 1
+        if c == head:
+            gdb.write("list is consistent: {} node(s)\n".format(nb))
+            return
+
+
+class LxListChk(gdb.Command):
+    """Verify a list consistency"""
+
+    def __init__(self):
+        super(LxListChk, self).__init__("lx-list-check", gdb.COMMAND_DATA,
+                                        gdb.COMPLETE_EXPRESSION)
+
+    def invoke(self, arg, from_tty):
+        argv = gdb.string_to_argv(arg)
+        if len(argv) != 1:
+            raise gdb.GdbError("lx-list-check takes one argument")
+        list_check(gdb.parse_and_eval(argv[0]))
+
+LxListChk()

scripts/gdb/linux/modules.py

@@ -0,0 +1,95 @@
+#
+# gdb helper commands and functions for Linux kernel debugging
+#
+#  module tools
+#
+# Copyright (c) Siemens AG, 2013
+#
+# Authors:
+#  Jan Kiszka <jan.kiszka@siemens.com>
+#
+# This work is licensed under the terms of the GNU GPL version 2.
+#
+
+import gdb
+
+from linux import cpus, utils, lists
+
+
+module_type = utils.CachedType("struct module")
+
+
+def module_list():
+    global module_type
+    modules = utils.gdb_eval_or_none("modules")
+    if modules is None:
+        return
+
+    module_ptr_type = module_type.get_type().pointer()
+
+    for module in lists.list_for_each_entry(modules, module_ptr_type, "list"):
+        yield module
+
+
+def find_module_by_name(name):
+    for module in module_list():
+        if module['name'].string() == name:
+            return module
+    return None
+
+
+class LxModule(gdb.Function):
+    """Find module by name and return the module variable.
+
+$lx_module("MODULE"): Given the name MODULE, iterate over all loaded modules
+of the target and return that module variable which MODULE matches."""
+
+    def __init__(self):
+        super(LxModule, self).__init__("lx_module")
+
+    def invoke(self, mod_name):
+        mod_name = mod_name.string()
+        module = find_module_by_name(mod_name)
+        if module:
+            return module.dereference()
+        else:
+            raise gdb.GdbError("Unable to find MODULE " + mod_name)
+
+
+LxModule()
+
+
+class LxLsmod(gdb.Command):
+    """List currently loaded modules."""
+
+    _module_use_type = utils.CachedType("struct module_use")
+
+    def __init__(self):
+        super(LxLsmod, self).__init__("lx-lsmod", gdb.COMMAND_DATA)
+
+    def invoke(self, arg, from_tty):
+        gdb.write(
+            "Address{0}    Module                  Size  Used by\n".format(
+                "        " if utils.get_long_type().sizeof == 8 else ""))
+
+        for module in module_list():
+            layout = module['core_layout']
+            gdb.write("{address} {name:<19} {size:>8}  {ref}".format(
+                address=str(layout['base']).split()[0],
+                name=module['name'].string(),
+                size=str(layout['size']),
+                ref=str(module['refcnt']['counter'] - 1)))
+
+            t = self._module_use_type.get_type().pointer()
+            first = True
+            sources = module['source_list']
+            for use in lists.list_for_each_entry(sources, t, "source_list"):
+                gdb.write("{separator}{name}".format(
+                    separator=" " if first else ",",
+                    name=use['source']['name'].string()))
+                first = False
+
+            gdb.write("\n")
+
+
+LxLsmod()

scripts/gdb/linux/proc.py

@@ -0,0 +1,270 @@
+#
+# gdb helper commands and functions for Linux kernel debugging
+#
+#  Kernel proc information reader
+#
+# Copyright (c) 2016 Linaro Ltd
+#
+# Authors:
+#  Kieran Bingham <kieran.bingham@linaro.org>
+#
+# This work is licensed under the terms of the GNU GPL version 2.
+#
+
+import gdb
+from linux import constants
+from linux import utils
+from linux import tasks
+from linux import lists
+from struct import *
+
+
+class LxCmdLine(gdb.Command):
+    """ Report the Linux Commandline used in the current kernel.
+        Equivalent to cat /proc/cmdline on a running target"""
+
+    def __init__(self):
+        super(LxCmdLine, self).__init__("lx-cmdline", gdb.COMMAND_DATA)
+
+    def invoke(self, arg, from_tty):
+        gdb.write(gdb.parse_and_eval("saved_command_line").string() + "\n")
+
+LxCmdLine()
+
+
+class LxVersion(gdb.Command):
+    """ Report the Linux Version of the current kernel.
+        Equivalent to cat /proc/version on a running target"""
+
+    def __init__(self):
+        super(LxVersion, self).__init__("lx-version", gdb.COMMAND_DATA)
+
+    def invoke(self, arg, from_tty):
+        # linux_banner should contain a newline
+        gdb.write(gdb.parse_and_eval("(char *)linux_banner").string())
+
+LxVersion()
+
+
+# Resource Structure Printers
+#  /proc/iomem
+#  /proc/ioports
+
+def get_resources(resource, depth):
+    while resource:
+        yield resource, depth
+
+        child = resource['child']
+        if child:
+            for res, deep in get_resources(child, depth + 1):
+                yield res, deep
+
+        resource = resource['sibling']
+
+
+def show_lx_resources(resource_str):
+        resource = gdb.parse_and_eval(resource_str)
+        width = 4 if resource['end'] < 0x10000 else 8
+        # Iterate straight to the first child
+        for res, depth in get_resources(resource['child'], 0):
+            start = int(res['start'])
+            end = int(res['end'])
+            gdb.write(" " * depth * 2 +
+                      "{0:0{1}x}-".format(start, width) +
+                      "{0:0{1}x} : ".format(end, width) +
+                      res['name'].string() + "\n")
+
+
+class LxIOMem(gdb.Command):
+    """Identify the IO memory resource locations defined by the kernel
+
+Equivalent to cat /proc/iomem on a running target"""
+
+    def __init__(self):
+        super(LxIOMem, self).__init__("lx-iomem", gdb.COMMAND_DATA)
+
+    def invoke(self, arg, from_tty):
+        return show_lx_resources("iomem_resource")
+
+LxIOMem()
+
+
+class LxIOPorts(gdb.Command):
+    """Identify the IO port resource locations defined by the kernel
+
+Equivalent to cat /proc/ioports on a running target"""
+
+    def __init__(self):
+        super(LxIOPorts, self).__init__("lx-ioports", gdb.COMMAND_DATA)
+
+    def invoke(self, arg, from_tty):
+        return show_lx_resources("ioport_resource")
+
+LxIOPorts()
+
+
+# Mount namespace viewer
+#  /proc/mounts
+
+def info_opts(lst, opt):
+    opts = ""
+    for key, string in lst.items():
+        if opt & key:
+            opts += string
+    return opts
+
+
+FS_INFO = {constants.LX_MS_SYNCHRONOUS: ",sync",
+           constants.LX_MS_MANDLOCK: ",mand",
+           constants.LX_MS_DIRSYNC: ",dirsync",
+           constants.LX_MS_NOATIME: ",noatime",
+           constants.LX_MS_NODIRATIME: ",nodiratime"}
+
+MNT_INFO = {constants.LX_MNT_NOSUID: ",nosuid",
+            constants.LX_MNT_NODEV: ",nodev",
+            constants.LX_MNT_NOEXEC: ",noexec",
+            constants.LX_MNT_NOATIME: ",noatime",
+            constants.LX_MNT_NODIRATIME: ",nodiratime",
+            constants.LX_MNT_RELATIME: ",relatime"}
+
+mount_type = utils.CachedType("struct mount")
+mount_ptr_type = mount_type.get_type().pointer()
+
+
+class LxMounts(gdb.Command):
+    """Report the VFS mounts of the current process namespace.
+
+Equivalent to cat /proc/mounts on a running target
+An integer value can be supplied to display the mount
+values of that process namespace"""
+
+    def __init__(self):
+        super(LxMounts, self).__init__("lx-mounts", gdb.COMMAND_DATA)
+
+    # Equivalent to proc_namespace.c:show_vfsmnt
+    # However, that has the ability to call into s_op functions
+    # whereas we cannot and must make do with the information we can obtain.
+    def invoke(self, arg, from_tty):
+        argv = gdb.string_to_argv(arg)
+        if len(argv) >= 1:
+            try:
+                pid = int(argv[0])
+            except:
+                raise gdb.GdbError("Provide a PID as integer value")
+        else:
+            pid = 1
+
+        task = tasks.get_task_by_pid(pid)
+        if not task:
+            raise gdb.GdbError("Couldn't find a process with PID {}"
+                               .format(pid))
+
+        namespace = task['nsproxy']['mnt_ns']
+        if not namespace:
+            raise gdb.GdbError("No namespace for current process")
+
+        for vfs in lists.list_for_each_entry(namespace['list'],
+                                             mount_ptr_type, "mnt_list"):
+            devname = vfs['mnt_devname'].string()
+            devname = devname if devname else "none"
+
+            pathname = ""
+            parent = vfs
+            while True:
+                mntpoint = parent['mnt_mountpoint']
+                pathname = utils.dentry_name(mntpoint) + pathname
+                if (parent == parent['mnt_parent']):
+                    break
+                parent = parent['mnt_parent']
+
+            if (pathname == ""):
+                pathname = "/"
+
+            superblock = vfs['mnt']['mnt_sb']
+            fstype = superblock['s_type']['name'].string()
+            s_flags = int(superblock['s_flags'])
+            m_flags = int(vfs['mnt']['mnt_flags'])
+            rd = "ro" if (s_flags & constants.LX_MS_RDONLY) else "rw"
+
+            gdb.write(
+                "{} {} {} {}{}{} 0 0\n"
+                .format(devname,
+                        pathname,
+                        fstype,
+                        rd,
+                        info_opts(FS_INFO, s_flags),
+                        info_opts(MNT_INFO, m_flags)))
+
+LxMounts()
+
+
+class LxFdtDump(gdb.Command):
+    """Output Flattened Device Tree header and dump FDT blob to the filename
+       specified as the command argument. Equivalent to
+       'cat /proc/fdt > fdtdump.dtb' on a running target"""
+
+    def __init__(self):
+        super(LxFdtDump, self).__init__("lx-fdtdump", gdb.COMMAND_DATA,
+                                        gdb.COMPLETE_FILENAME)
+
+    def fdthdr_to_cpu(self, fdt_header):
+
+        fdt_header_be = ">IIIIIII"
+        fdt_header_le = "<IIIIIII"
+
+        if utils.get_target_endianness() == 1:
+            output_fmt = fdt_header_le
+        else:
+            output_fmt = fdt_header_be
+
+        return unpack(output_fmt, pack(fdt_header_be,
+                                       fdt_header['magic'],
+                                       fdt_header['totalsize'],
+                                       fdt_header['off_dt_struct'],
+                                       fdt_header['off_dt_strings'],
+                                       fdt_header['off_mem_rsvmap'],
+                                       fdt_header['version'],
+                                       fdt_header['last_comp_version']))
+
+    def invoke(self, arg, from_tty):
+
+        if not constants.LX_CONFIG_OF:
+            raise gdb.GdbError("Kernel not compiled with CONFIG_OF\n")
+
+        if len(arg) == 0:
+            filename = "fdtdump.dtb"
+        else:
+            filename = arg
+
+        py_fdt_header_ptr = gdb.parse_and_eval(
+            "(const struct fdt_header *) initial_boot_params")
+        py_fdt_header = py_fdt_header_ptr.dereference()
+
+        fdt_header = self.fdthdr_to_cpu(py_fdt_header)
+
+        if fdt_header[0] != constants.LX_OF_DT_HEADER:
+            raise gdb.GdbError("No flattened device tree magic found\n")
+
+        gdb.write("fdt_magic:         0x{:02X}\n".format(fdt_header[0]))
+        gdb.write("fdt_totalsize:     0x{:02X}\n".format(fdt_header[1]))
+        gdb.write("off_dt_struct:     0x{:02X}\n".format(fdt_header[2]))
+        gdb.write("off_dt_strings:    0x{:02X}\n".format(fdt_header[3]))
+        gdb.write("off_mem_rsvmap:    0x{:02X}\n".format(fdt_header[4]))
+        gdb.write("version:           {}\n".format(fdt_header[5]))
+        gdb.write("last_comp_version: {}\n".format(fdt_header[6]))
+
+        inf = gdb.inferiors()[0]
+        fdt_buf = utils.read_memoryview(inf, py_fdt_header_ptr,
+                                        fdt_header[1]).tobytes()
+
+        try:
+            f = open(filename, 'wb')
+        except:
+            raise gdb.GdbError("Could not open file to dump fdt")
+
+        f.write(fdt_buf)
+        f.close()
+
+        gdb.write("Dumped fdt blob to " + filename + "\n")
+
+LxFdtDump()

scripts/gdb/linux/symbols.py

@@ -0,0 +1,177 @@
+#
+# gdb helper commands and functions for Linux kernel debugging
+#
+#  load kernel and module symbols
+#
+# Copyright (c) Siemens AG, 2011-2013
+#
+# Authors:
+#  Jan Kiszka <jan.kiszka@siemens.com>
+#
+# This work is licensed under the terms of the GNU GPL version 2.
+#
+
+import gdb
+import os
+import re
+
+from linux import modules
+
+
+if hasattr(gdb, 'Breakpoint'):
+    class LoadModuleBreakpoint(gdb.Breakpoint):
+        def __init__(self, spec, gdb_command):
+            super(LoadModuleBreakpoint, self).__init__(spec, internal=True)
+            self.silent = True
+            self.gdb_command = gdb_command
+
+        def stop(self):
+            module = gdb.parse_and_eval("mod")
+            module_name = module['name'].string()
+            cmd = self.gdb_command
+
+            # enforce update if object file is not found
+            cmd.module_files_updated = False
+
+            # Disable pagination while reporting symbol (re-)loading.
+            # The console input is blocked in this context so that we would
+            # get stuck waiting for the user to acknowledge paged output.
+            show_pagination = gdb.execute("show pagination", to_string=True)
+            pagination = show_pagination.endswith("on.\n")
+            gdb.execute("set pagination off")
+
+            if module_name in cmd.loaded_modules:
+                gdb.write("refreshing all symbols to reload module "
+                          "'{0}'\n".format(module_name))
+                cmd.load_all_symbols()
+            else:
+                cmd.load_module_symbols(module)
+
+            # restore pagination state
+            gdb.execute("set pagination %s" % ("on" if pagination else "off"))
+
+            return False
+
+
+class LxSymbols(gdb.Command):
+    """(Re-)load symbols of Linux kernel and currently loaded modules.
+
+The kernel (vmlinux) is taken from the current working directly. Modules (.ko)
+are scanned recursively, starting in the same directory. Optionally, the module
+search path can be extended by a space separated list of paths passed to the
+lx-symbols command."""
+
+    module_paths = []
+    module_files = []
+    module_files_updated = False
+    loaded_modules = []
+    breakpoint = None
+
+    def __init__(self):
+        super(LxSymbols, self).__init__("lx-symbols", gdb.COMMAND_FILES,
+                                        gdb.COMPLETE_FILENAME)
+
+    def _update_module_files(self):
+        self.module_files = []
+        for path in self.module_paths:
+            gdb.write("scanning for modules in {0}\n".format(path))
+            for root, dirs, files in os.walk(path):
+                for name in files:
+                    if name.endswith(".ko"):
+                        self.module_files.append(root + "/" + name)
+        self.module_files_updated = True
+
+    def _get_module_file(self, module_name):
+        module_pattern = ".*/{0}\.ko$".format(
+            module_name.replace("_", r"[_\-]"))
+        for name in self.module_files:
+            if re.match(module_pattern, name) and os.path.exists(name):
+                return name
+        return None
+
+    def _section_arguments(self, module):
+        try:
+            sect_attrs = module['sect_attrs'].dereference()
+        except gdb.error:
+            return ""
+        attrs = sect_attrs['attrs']
+        section_name_to_address = {
+            attrs[n]['battr']['attr']['name'].string(): attrs[n]['address']
+            for n in range(int(sect_attrs['nsections']))}
+        args = []
+        for section_name in [".data", ".data..read_mostly", ".rodata", ".bss",
+                             ".text", ".text.hot", ".text.unlikely"]:
+            address = section_name_to_address.get(section_name)
+            if address:
+                args.append(" -s {name} {addr}".format(
+                    name=section_name, addr=str(address)))
+        return "".join(args)
+
+    def load_module_symbols(self, module):
+        module_name = module['name'].string()
+        module_addr = str(module['core_layout']['base']).split()[0]
+
+        module_file = self._get_module_file(module_name)
+        if not module_file and not self.module_files_updated:
+            self._update_module_files()
+            module_file = self._get_module_file(module_name)
+
+        if module_file:
+            gdb.write("loading @{addr}: {filename}\n".format(
+                addr=module_addr, filename=module_file))
+            cmdline = "add-symbol-file {filename} {addr}{sections}".format(
+                filename=module_file,
+                addr=module_addr,
+                sections=self._section_arguments(module))
+            gdb.execute(cmdline, to_string=True)
+            if module_name not in self.loaded_modules:
+                self.loaded_modules.append(module_name)
+        else:
+            gdb.write("no module object found for '{0}'\n".format(module_name))
+
+    def load_all_symbols(self):
+        gdb.write("loading vmlinux\n")
+
+        # Dropping symbols will disable all breakpoints. So save their states
+        # and restore them afterward.
+        saved_states = []
+        if hasattr(gdb, 'breakpoints') and not gdb.breakpoints() is None:
+            for bp in gdb.breakpoints():
+                saved_states.append({'breakpoint': bp, 'enabled': bp.enabled})
+
+        # drop all current symbols and reload vmlinux
+        gdb.execute("symbol-file", to_string=True)
+        gdb.execute("symbol-file vmlinux")
+
+        self.loaded_modules = []
+        module_list = modules.module_list()
+        if not module_list:
+            gdb.write("no modules found\n")
+        else:
+            [self.load_module_symbols(module) for module in module_list]
+
+        for saved_state in saved_states:
+            saved_state['breakpoint'].enabled = saved_state['enabled']
+
+    def invoke(self, arg, from_tty):
+        self.module_paths = [os.path.expanduser(p) for p in arg.split()]
+        self.module_paths.append(os.getcwd())
+
+        # enforce update
+        self.module_files = []
+        self.module_files_updated = False
+
+        self.load_all_symbols()
+
+        if hasattr(gdb, 'Breakpoint'):
+            if self.breakpoint is not None:
+                self.breakpoint.delete()
+                self.breakpoint = None
+            self.breakpoint = LoadModuleBreakpoint(
+                "kernel/module.c:do_init_module", self)
+        else:
+            gdb.write("Note: symbol update on module loading not supported "
+                      "with this gdb version\n")
+
+
+LxSymbols()

scripts/gdb/linux/tasks.py

@@ -0,0 +1,137 @@
+#
+# gdb helper commands and functions for Linux kernel debugging
+#
+#  task & thread tools
+#
+# Copyright (c) Siemens AG, 2011-2013
+#
+# Authors:
+#  Jan Kiszka <jan.kiszka@siemens.com>
+#
+# This work is licensed under the terms of the GNU GPL version 2.
+#
+
+import gdb
+
+from linux import utils
+
+
+task_type = utils.CachedType("struct task_struct")
+
+
+def task_lists():
+    task_ptr_type = task_type.get_type().pointer()
+    init_task = gdb.parse_and_eval("init_task").address
+    t = g = init_task
+
+    while True:
+        while True:
+            yield t
+
+            t = utils.container_of(t['thread_group']['next'],
+                                   task_ptr_type, "thread_group")
+            if t == g:
+                break
+
+        t = g = utils.container_of(g['tasks']['next'],
+                                   task_ptr_type, "tasks")
+        if t == init_task:
+            return
+
+
+def get_task_by_pid(pid):
+    for task in task_lists():
+        if int(task['pid']) == pid:
+            return task
+    return None
+
+
+class LxTaskByPidFunc(gdb.Function):
+    """Find Linux task by PID and return the task_struct variable.
+
+$lx_task_by_pid(PID): Given PID, iterate over all tasks of the target and
+return that task_struct variable which PID matches."""
+
+    def __init__(self):
+        super(LxTaskByPidFunc, self).__init__("lx_task_by_pid")
+
+    def invoke(self, pid):
+        task = get_task_by_pid(pid)
+        if task:
+            return task.dereference()
+        else:
+            raise gdb.GdbError("No task of PID " + str(pid))
+
+
+LxTaskByPidFunc()
+
+
+class LxPs(gdb.Command):
+    """Dump Linux tasks."""
+
+    def __init__(self):
+        super(LxPs, self).__init__("lx-ps", gdb.COMMAND_DATA)
+
+    def invoke(self, arg, from_tty):
+        for task in task_lists():
+            gdb.write("{address} {pid} {comm}\n".format(
+                address=task,
+                pid=task["pid"],
+                comm=task["comm"].string()))
+
+LxPs()
+
+
+thread_info_type = utils.CachedType("struct thread_info")
+
+ia64_task_size = None
+
+
+def get_thread_info(task):
+    thread_info_ptr_type = thread_info_type.get_type().pointer()
+    if utils.is_target_arch("ia64"):
+        global ia64_task_size
+        if ia64_task_size is None:
+            ia64_task_size = gdb.parse_and_eval("sizeof(struct task_struct)")
+        thread_info_addr = task.address + ia64_task_size
+        thread_info = thread_info_addr.cast(thread_info_ptr_type)
+    else:
+        if task.type.fields()[0].type == thread_info_type.get_type():
+            return task['thread_info']
+        thread_info = task['stack'].cast(thread_info_ptr_type)
+    return thread_info.dereference()
+
+
+class LxThreadInfoFunc (gdb.Function):
+    """Calculate Linux thread_info from task variable.
+
+$lx_thread_info(TASK): Given TASK, return the corresponding thread_info
+variable."""
+
+    def __init__(self):
+        super(LxThreadInfoFunc, self).__init__("lx_thread_info")
+
+    def invoke(self, task):
+        return get_thread_info(task)
+
+
+LxThreadInfoFunc()
+
+
+class LxThreadInfoByPidFunc (gdb.Function):
+    """Calculate Linux thread_info from task variable found by pid
+
+$lx_thread_info_by_pid(PID): Given PID, return the corresponding thread_info
+variable."""
+
+    def __init__(self):
+        super(LxThreadInfoByPidFunc, self).__init__("lx_thread_info_by_pid")
+
+    def invoke(self, pid):
+        task = get_task_by_pid(pid)
+        if task:
+            return get_thread_info(task.dereference())
+        else:
+            raise gdb.GdbError("No task of PID " + str(pid))
+
+LxThreadInfoByPidFunc()

scripts/gdb/linux/utils.py

@@ -0,0 +1,184 @@
+#
+# gdb helper commands and functions for Linux kernel debugging
+#
+#  common utilities
+#
+# Copyright (c) Siemens AG, 2011-2013
+#
+# Authors:
+#  Jan Kiszka <jan.kiszka@siemens.com>
+#
+# This work is licensed under the terms of the GNU GPL version 2.
+#
+
+import gdb
+
+
+class CachedType:
+    def __init__(self, name):
+        self._type = None
+        self._name = name
+
+    def _new_objfile_handler(self, event):
+        self._type = None
+        gdb.events.new_objfile.disconnect(self._new_objfile_handler)
+
+    def get_type(self):
+        if self._type is None:
+            self._type = gdb.lookup_type(self._name)
+            if self._type is None:
+                raise gdb.GdbError(
+                    "cannot resolve type '{0}'".format(self._name))
+            if hasattr(gdb, 'events') and hasattr(gdb.events, 'new_objfile'):
+                gdb.events.new_objfile.connect(self._new_objfile_handler)
+        return self._type
+
+
+long_type = CachedType("long")
+
+
+def get_long_type():
+    global long_type
+    return long_type.get_type()
+
+
+def offset_of(typeobj, field):
+    element = gdb.Value(0).cast(typeobj)
+    return int(str(element[field].address).split()[0], 16)
+
+
+def container_of(ptr, typeobj, member):
+    return (ptr.cast(get_long_type()) -
+            offset_of(typeobj, member)).cast(typeobj)
+
+
+class ContainerOf(gdb.Function):
+    """Return pointer to containing data structure.
+
+$container_of(PTR, "TYPE", "ELEMENT"): Given PTR, return a pointer to the
+data structure of the type TYPE in which PTR is the address of ELEMENT.
+Note that TYPE and ELEMENT have to be quoted as strings."""
+
+    def __init__(self):
+        super(ContainerOf, self).__init__("container_of")
+
+    def invoke(self, ptr, typename, elementname):
+        return container_of(ptr, gdb.lookup_type(typename.string()).pointer(),
+                            elementname.string())
+
+ContainerOf()
+
+
+BIG_ENDIAN = 0
+LITTLE_ENDIAN = 1
+target_endianness = None
+
+
+def get_target_endianness():
+    global target_endianness
+    if target_endianness is None:
+        endian = gdb.execute("show endian", to_string=True)
+        if "little endian" in endian:
+            target_endianness = LITTLE_ENDIAN
+        elif "big endian" in endian:
+            target_endianness = BIG_ENDIAN
+        else:
+            raise gdb.GdbError("unknown endianness '{0}'".format(str(endian)))
+    return target_endianness
+
+
+def read_memoryview(inf, start, length):
+    return memoryview(inf.read_memory(start, length))
+
+
+def read_u16(buffer):
+    value = [0, 0]
+
+    if type(buffer[0]) is str:
+        value[0] = ord(buffer[0])
+        value[1] = ord(buffer[1])
+    else:
+        value[0] = buffer[0]
+        value[1] = buffer[1]
+
+    if get_target_endianness() == LITTLE_ENDIAN:
+        return value[0] + (value[1] << 8)
+    else:
+        return value[1] + (value[0] << 8)
+
+
+def read_u32(buffer):
+    if get_target_endianness() == LITTLE_ENDIAN:
+        return read_u16(buffer[0:2]) + (read_u16(buffer[2:4]) << 16)
+    else:
+        return read_u16(buffer[2:4]) + (read_u16(buffer[0:2]) << 16)
+
+
+def read_u64(buffer):
+    if get_target_endianness() == LITTLE_ENDIAN:
+        return read_u32(buffer[0:4]) + (read_u32(buffer[4:8]) << 32)
+    else:
+        return read_u32(buffer[4:8]) + (read_u32(buffer[0:4]) << 32)
+
+
+target_arch = None
+
+
+def is_target_arch(arch):
+    if hasattr(gdb.Frame, 'architecture'):
+        return arch in gdb.newest_frame().architecture().name()
+    else:
+        global target_arch
+        if target_arch is None:
+            target_arch = gdb.execute("show architecture", to_string=True)
+        return arch in target_arch
+
+
+GDBSERVER_QEMU = 0
+GDBSERVER_KGDB = 1
+gdbserver_type = None
+
+
+def get_gdbserver_type():
+    def exit_handler(event):
+        global gdbserver_type
+        gdbserver_type = None
+        gdb.events.exited.disconnect(exit_handler)
+
+    def probe_qemu():
+        try:
+            return gdb.execute("monitor info version", to_string=True) != ""
+        except:
+            return False
+
+    def probe_kgdb():
+        try:
+            thread_info = gdb.execute("info thread 2", to_string=True)
+            return "shadowCPU0" in thread_info
+        except:
+            return False
+
+    global gdbserver_type
+    if gdbserver_type is None:
+        if probe_qemu():
+            gdbserver_type = GDBSERVER_QEMU
+        elif probe_kgdb():
+            gdbserver_type = GDBSERVER_KGDB
+        if gdbserver_type is not None and hasattr(gdb, 'events'):
+            gdb.events.exited.connect(exit_handler)
+    return gdbserver_type
+
+
+def gdb_eval_or_none(expresssion):
+    try:
+        return gdb.parse_and_eval(expresssion)
+    except:
+        return None
+
+
+def dentry_name(d):
+    parent = d['d_parent']
+    if parent == d or parent == 0:
+        return ""
+    p = dentry_name(d['d_parent']) + "/"
+    return p + d['d_iname'].string()

scripts/gdb/vmlinux-gdb.py

@@ -0,0 +1,33 @@
+#
+# gdb helper commands and functions for Linux kernel debugging
+#
+#  loader module
+#
+# Copyright (c) Siemens AG, 2012, 2013
+#
+# Authors:
+#  Jan Kiszka <jan.kiszka@siemens.com>
+#
+# This work is licensed under the terms of the GNU GPL version 2.
+#
+
+import os
+
+sys.path.insert(0, os.path.dirname(__file__) + "/scripts/gdb")
+
+try:
+    gdb.parse_and_eval("0")
+    gdb.execute("", to_string=True)
+except:
+    gdb.write("NOTE: gdb 7.2 or later required for Linux helper scripts to "
+              "work.\n")
+else:
+    import linux.utils
+    import linux.symbols
+    import linux.modules
+    import linux.dmesg
+    import linux.tasks
+    import linux.cpus
+    import linux.lists
+    import linux.proc
+    import linux.constants