Messages in this thread Patch in this message | | | Date | Fri, 24 Apr 2015 11:57:30 +1000 | From | Thiébaud Weksteen <> | Subject | [PATCH v2] scripts/gdb: Add command to check list consistency |
| |
Add a gdb script to verify the consistency of lists.
Signed-off-by: Thiébaud Weksteen <thiebaud@weksteen.fr> --- Implement suggestions from Jan.
Changes in v2: - Add copyright line - Rename check_list to list_check - Remove casting and only accept (struct list_head) object - Add error message if argument is missing - Reformat error messages to include address of nodes
Example of use: (gdb) lx-list-check workqueues Starting with: {next = 0xf3aea5a8, prev = 0xf580e668} list is consistent: 30 node(s) (gdb) set *((int *) 0xf3934908) = 0x0 (gdb) lx-list-check workqueues Starting with: {next = 0xf3aea5a8, prev = 0xf580e668} next is not accessible: current@0xf3934908={next = 0x0, prev = 0xf3aea5a8} (gdb) set *((int *) 0xf3934908) = 0xdeadbeef (gdb) lx-list-check workqueues Starting with: {next = 0xf3aea5a8, prev = 0xf580e668} next.prev != current: current@0xf3934908={next = 0xdeadbeef, prev = 0xf3aea5a8} next@0xdeadbeef={next = 0x0, prev = 0x0} (gdb) set *((int *) 0xf3934908) = 0xf537f188 (gdb) lx-list-check workqueues Starting with: {next = 0xf3aea5a8, prev = 0xf580e668} list is consistent: 30 node(s)
scripts/gdb/linux/lists.py | 89 ++++++++++++++++++++++++++++++++++++++++++++++ scripts/gdb/vmlinux-gdb.py | 1 + 2 files changed, 90 insertions(+) create mode 100644 scripts/gdb/linux/lists.py
diff --git a/scripts/gdb/linux/lists.py b/scripts/gdb/linux/lists.py new file mode 100644 index 0000000..2a94b54 --- /dev/null +++ b/scripts/gdb/linux/lists.py @@ -0,0 +1,89 @@ +# +# 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_check(head): + nb = 0 + c = head + if (c.type != list_head.get_type()): + raise gdb.GdbError('The argument should be of type (struct list_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) + + 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() diff --git a/scripts/gdb/vmlinux-gdb.py b/scripts/gdb/vmlinux-gdb.py index 4848928..ce82bf5 100644 --- a/scripts/gdb/vmlinux-gdb.py +++ b/scripts/gdb/vmlinux-gdb.py @@ -28,3 +28,4 @@ else: import linux.dmesg import linux.tasks import linux.cpus + import linux.lists -- 2.1.0
| |