Commit f4efbdaf authored by Glenn Washburn's avatar Glenn Washburn Committed by Andrew Morton
Browse files

scripts/gdb: create linux/vfs.py for VFS related GDB helpers 

Patch series "GDB VFS utils".

I've created a couple GDB convenience functions that I found useful when
debugging some VFS issues and figure others might find them useful.  For
instance, they are useful in setting conditional breakpoints on VFS
functions where you only care if the dentry path is a certain value.  I
took the opportunity to create a new "vfs" python module to give VFS
related utilities a home.


This patch (of 2):

This will allow for more VFS specific GDB helpers to be collected in one
place.  Move utils.dentry_name into the vfs modules.  Also a local
variable in proc.py was changed from vfs to mnt to prevent a naming
collision with the new vfs module.

[akpm@linux-foundation.org: add SPDX-License-Identifier]
Link: https://lkml.kernel.org/r/cover.1677631565.git.development@efficientek.com
Link: https://lkml.kernel.org/r/7bba4c065a8c2c47f1fc5b03a7278005b04db251.1677631565.git.development@efficientek.com


Signed-off-by: default avatarGlenn Washburn <development@efficientek.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Antonio Borneo <antonio.borneo@foss.st.com>
Cc: Jan Kiszka <jan.kiszka@siemens.com>
Cc: John Ogness <john.ogness@linutronix.de>
Cc: Kieran Bingham <kbingham@kernel.org>
Cc: Petr Mladek <pmladek@suse.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 31088f6f

scripts/gdb/linux/proc.py

+9 −7
Original line number Diff line number Diff line 
# SPDX-License-Identifier: GPL-2.0

#

# gdb helper commands and functions for Linux kernel debugging

#
@@ -16,6 +17,7 @@ from linux import constants 
from linux import utils

from linux import tasks

from linux import lists

from linux import vfs

from struct import *
@@ -170,16 +172,16 @@ values of that process namespace""" 
        gdb.write("{:^18} {:^15} {:>9} {} {} options\n".format(

                  "mount", "super_block", "devname", "pathname", "fstype"))



        for vfs in lists.list_for_each_entry(namespace['list'],

        for mnt in lists.list_for_each_entry(namespace['list'],

                                             mount_ptr_type, "mnt_list"):

            devname = vfs['mnt_devname'].string()

            devname = mnt['mnt_devname'].string()

            devname = devname if devname else "none"



            pathname = ""

            parent = vfs

            parent = mnt

            while True:

                mntpoint = parent['mnt_mountpoint']

                pathname = utils.dentry_name(mntpoint) + pathname

                pathname = vfs.dentry_name(mntpoint) + pathname

                if (parent == parent['mnt_parent']):

                    break

                parent = parent['mnt_parent']
@@ -187,14 +189,14 @@ values of that process namespace""" 
            if (pathname == ""):

                pathname = "/"



            superblock = vfs['mnt']['mnt_sb']

            superblock = mnt['mnt']['mnt_sb']

            fstype = superblock['s_type']['name'].string()

            s_flags = int(superblock['s_flags'])

            m_flags = int(vfs['mnt']['mnt_flags'])

            m_flags = int(mnt['mnt']['mnt_flags'])

            rd = "ro" if (s_flags & constants.LX_SB_RDONLY) else "rw"



            gdb.write("{} {} {} {} {} {}{}{} 0 0\n".format(

                      vfs.format_string(), superblock.format_string(), devname,

                      mnt.format_string(), superblock.format_string(), devname,

                      pathname, fstype, rd, info_opts(FS_INFO, s_flags),

                      info_opts(MNT_INFO, m_flags)))

scripts/gdb/linux/utils.py

+0 −8
Original line number Diff line number Diff line
@@ -196,11 +196,3 @@ def gdb_eval_or_none(expresssion): 
        return gdb.parse_and_eval(expresssion)

    except gdb.error:

        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/linux/vfs.py

0 → 100644
+22 −0
Original line number Diff line number Diff line 
#

# gdb helper commands and functions for Linux kernel debugging

#

#  VFS tools

#

# Copyright (c) 2023 Glenn Washburn

# Copyright (c) 2016 Linaro Ltd

#

# Authors:

#  Glenn Washburn <development@efficientek.com>

#  Kieran Bingham <kieran.bingham@linaro.org>

#

# This work is licensed under the terms of the GNU GPL version 2.

#





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

+1 −0
Original line number Diff line number Diff line
@@ -40,6 +40,7 @@ else: 
    import linux.clk

    import linux.genpd

    import linux.device

    import linux.vfs

    import linux.mm

    import linux.radixtree

    import linux.interrupts