From c1a153992ea86307d2b8c3c0be2e060102b02aff Mon Sep 17 00:00:00 2001 From: Kieran Bingham Date: Mon, 23 May 2016 16:24:59 -0700 Subject: [PATCH] scripts/gdb: add mount point list command lx-mounts will identify current mount points based on the 'init_task' namespace by default, as we do not yet have a kernel thread list implementation to select the current running thread. Optionally, a user can specify a PID to list from that process' namespace Link: http://lkml.kernel.org/r/e614c7bc32d2350b4ff1627ec761a7148e65bfe6.1462865983.git.jan.kiszka@siemens.com Signed-off-by: Kieran Bingham Signed-off-by: Jan Kiszka Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- scripts/gdb/linux/constants.py.in | 20 +++++++ scripts/gdb/linux/proc.py | 99 +++++++++++++++++++++++++++++++ 2 files changed, 119 insertions(+) diff --git a/scripts/gdb/linux/constants.py.in b/scripts/gdb/linux/constants.py.in index 79d9d0092452..7986f4e0da12 100644 --- a/scripts/gdb/linux/constants.py.in +++ b/scripts/gdb/linux/constants.py.in @@ -12,7 +12,11 @@ * */ +#include +#include + /* We need to stringify expanded macros so that they can be parsed */ + #define STRING(x) #x #define XSTRING(x) STRING(x) @@ -30,3 +34,19 @@ 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) diff --git a/scripts/gdb/linux/proc.py b/scripts/gdb/linux/proc.py index d855b2fd9a06..38b1f09d1cd9 100644 --- a/scripts/gdb/linux/proc.py +++ b/scripts/gdb/linux/proc.py @@ -12,6 +12,10 @@ # import gdb +from linux import constants +from linux import utils +from linux import tasks +from linux import lists class LxCmdLine(gdb.Command): @@ -96,3 +100,98 @@ Equivalent to cat /proc/ioports on a running target""" 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() -- 2.20.1