From f4efbdaf59e959507a1a931ec4afecdfb09db76e Mon Sep 17 00:00:00 2001 From: Glenn Washburn Date: Tue, 28 Feb 2023 18:53:34 -0600 Subject: 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 Cc: Alexander Viro Cc: Antonio Borneo Cc: Jan Kiszka Cc: John Ogness Cc: Kieran Bingham Cc: Petr Mladek Signed-off-by: Andrew Morton --- scripts/gdb/linux/vfs.py | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+) create mode 100644 scripts/gdb/linux/vfs.py (limited to 'scripts/gdb/linux/vfs.py') 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 +# Kieran Bingham +# +# 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() -- cgit From 5a10562bdeb58006de4b1cd5f671b7da26b20bb3 Mon Sep 17 00:00:00 2001 From: Glenn Washburn Date: Tue, 28 Feb 2023 18:53:35 -0600 Subject: scripts/gdb: add GDB convenience functions $lx_dentry_name() and $lx_i_dentry() $lx_dentry_name() generates a full VFS path from a given dentry pointer, and $lx_i_dentry() returns the dentry pointer associated with the given inode pointer, if there is one. Link: https://lkml.kernel.org/r/c9a5ad8efbfbd2cc6559e082734eed7628f43a16.1677631565.git.development@efficientek.com Signed-off-by: Glenn Washburn Cc: Alexander Viro Cc: Antonio Borneo Cc: Jan Kiszka Cc: John Ogness Cc: Kieran Bingham Cc: Petr Mladek Signed-off-by: Andrew Morton --- scripts/gdb/linux/vfs.py | 37 +++++++++++++++++++++++++++++++++++++ 1 file changed, 37 insertions(+) (limited to 'scripts/gdb/linux/vfs.py') diff --git a/scripts/gdb/linux/vfs.py b/scripts/gdb/linux/vfs.py index 62d4f9ad7d79..c77b9ce75f6d 100644 --- a/scripts/gdb/linux/vfs.py +++ b/scripts/gdb/linux/vfs.py @@ -13,6 +13,9 @@ # This work is licensed under the terms of the GNU GPL version 2. # +import gdb +from linux import utils + def dentry_name(d): parent = d['d_parent'] @@ -20,3 +23,37 @@ def dentry_name(d): return "" p = dentry_name(d['d_parent']) + "/" return p + d['d_iname'].string() + +class DentryName(gdb.Function): + """Return string of the full path of a dentry. + +$lx_dentry_name(PTR): Given PTR to a dentry struct, return a string +of the full path of the dentry.""" + + def __init__(self): + super(DentryName, self).__init__("lx_dentry_name") + + def invoke(self, dentry_ptr): + return dentry_name(dentry_ptr) + +DentryName() + + +dentry_type = utils.CachedType("struct dentry") + +class InodeDentry(gdb.Function): + """Return dentry pointer for inode. + +$lx_i_dentry(PTR): Given PTR to an inode struct, return a pointer to +the associated dentry struct, if there is one.""" + + def __init__(self): + super(InodeDentry, self).__init__("lx_i_dentry") + + def invoke(self, inode_ptr): + d_u = inode_ptr["i_dentry"]["first"] + if d_u == 0: + return "" + return utils.container_of(d_u, dentry_type.get_type().pointer(), "d_u") + +InodeDentry() -- cgit