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: Glenn 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: Andrew Morton <akpm@linux-foundation.org>

4 files changed, 32 insertions, 15 deletions

diff --git a/scripts/gdb/linux/proc.py b/scripts/gdb/linux/proc.py
index 09cd871925a5..43c687e7a69d 100644
--- a/scripts/gdb/linux/proc.py
+++ b/scripts/gdb/linux/proc.py
@@ -1,3 +1,4 @@
+# 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)))
 
diff --git a/scripts/gdb/linux/utils.py b/scripts/gdb/linux/utils.py
index 7f36aee32ac6..9f44df13761e 100644
--- a/scripts/gdb/linux/utils.py
+++ b/scripts/gdb/linux/utils.py
@@ -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()
diff --git a/scripts/gdb/linux/vfs.py b/scripts/gdb/linux/vfs.py
new file mode 100644
index 000000000000..62d4f9ad7d79
--- /dev/null
+++ b/scripts/gdb/linux/vfs.py
@@ -0,0 +1,22 @@
+#
+# 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()
diff --git a/scripts/gdb/vmlinux-gdb.py b/scripts/gdb/vmlinux-gdb.py
index 2a72f91059b5..2d32308c3f7a 100644
--- a/scripts/gdb/vmlinux-gdb.py
+++ b/scripts/gdb/vmlinux-gdb.py
@@ -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