Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933438Ab2K0KMP (ORCPT ); Tue, 27 Nov 2012 05:12:15 -0500 Received: from goliath.siemens.de ([192.35.17.28]:23771 "EHLO goliath.siemens.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933503Ab2K0KMG (ORCPT ); Tue, 27 Nov 2012 05:12:06 -0500 From: Jan Kiszka To: Andrew Morton , linux-kernel@vger.kernel.org Cc: Jason Wessel , kgdb-bugreport@lists.sourceforge.net, Andi Kleen , Tom Tromey Subject: [PATCH v3 02/13] scripts/gdb: Add container_of helper and convenience function Date: Tue, 27 Nov 2012 11:11:33 +0100 Message-Id: <6f3dc2946a817ab7e39eb1fdcf9d15a8af2817b6.1354011091.git.jan.kiszka@siemens.com> X-Mailer: git-send-email 1.7.3.4 In-Reply-To: References: In-Reply-To: References: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2483 Lines: 78 Provide an internal helper with container_of semantics. As type lookups are very slow in gdb-python and we need a type "long" for this, cache the reference to this type object. Then export the helper also as a convenience function form use at the gdb command line. Signed-off-by: Jan Kiszka --- scripts/gdb/utils.py | 41 +++++++++++++++++++++++++++++++++++++++++ scripts/gdb/vmlinux-gdb.py | 2 ++ 2 files changed, 43 insertions(+), 0 deletions(-) diff --git a/scripts/gdb/utils.py b/scripts/gdb/utils.py index 14e72ec..f97ef79 100644 --- a/scripts/gdb/utils.py +++ b/scripts/gdb/utils.py @@ -15,3 +15,44 @@ import gdb import re gdb_version = re.sub("^[^0-9]*", "", gdb.VERSION) + +long_type = None + +def get_type(type_name): + t = gdb.lookup_type(type_name) + if t == None: + raise gdb.GdbError("cannot resolve type '%s'" % type_name) + return t + +def get_long_type(): + global long_type + if long_type == None: + long_type = get_type("long") + return long_type + + +def offset_of(typeobj, field): + element = gdb.Value(0).cast(typeobj) + return int(str(element[field].address).split()[0], 16) + +def container_of(ptr, typeobj, member): + return (ptr.cast(get_long_type()) - + offset_of(typeobj, member)).cast(typeobj) + + +class ContainerOf(gdb.Function): + __doc__ = "Return pointer to containing data structure.\n" \ + "\n" \ + "$container_of(PTR, \"TYPE\", \"ELEMENT\"): Given PTR, return a pointer to the\n" \ + "data structure of the type TYPE in which PTR is the address of ELEMENT.\n" \ + "Note that TYPE and ELEMENT have to be quoted as strings." + + def __init__(self): + super(ContainerOf, self).__init__("container_of") + + def invoke(self, ptr, typename, elementname): + return container_of(ptr, + gdb.lookup_type(typename.string()).pointer(), + elementname.string()) + +ContainerOf() diff --git a/scripts/gdb/vmlinux-gdb.py b/scripts/gdb/vmlinux-gdb.py index ff75a85..42774d3 100644 --- a/scripts/gdb/vmlinux-gdb.py +++ b/scripts/gdb/vmlinux-gdb.py @@ -20,3 +20,5 @@ from utils import gdb_version if gdb_version < "7.1": print "NOTE: gdb 7.1 or later required for Linux helper scripts " \ "to work." +else: + import utils -- 1.7.3.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/