Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752942AbaFFRYm (ORCPT ); Fri, 6 Jun 2014 13:24:42 -0400 Received: from goliath.siemens.de ([192.35.17.28]:34741 "EHLO goliath.siemens.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752420AbaFFRTh (ORCPT ); Fri, 6 Jun 2014 13:19:37 -0400 From: Jan Kiszka To: Thomas Gleixner , Andrew Morton , linux-kernel@vger.kernel.org Cc: Jason Wessel , kgdb-bugreport@lists.sourceforge.net, Andi Kleen , Tom Tromey , Ben Widawsky , Borislav Petkov , Tatiana Al-Chueyr Martins , "David S. Miller" , sparclinux@vger.kernel.org Subject: [PATCH v8 17/22] scripts/gdb: Add internal helper and convenience function for per-cpu lookup Date: Fri, 6 Jun 2014 19:18:58 +0200 Message-Id: <8798e406453ac369607924e5b57ad9a41e40e15e.1402075141.git.jan.kiszka@siemens.com> X-Mailer: git-send-email 1.8.1.1.298.ge7eed54 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 This function allows to obtain a per-cpu variable, either of the current or an explicitly specified CPU. Note: sparc64 version is untested. CC: "David S. Miller" CC: sparclinux@vger.kernel.org Signed-off-by: Jan Kiszka --- scripts/gdb/linux/cpus.py | 68 ++++++++++++++++++++++++++++++++++++++++++++++ scripts/gdb/vmlinux-gdb.py | 1 + 2 files changed, 69 insertions(+) create mode 100644 scripts/gdb/linux/cpus.py diff --git a/scripts/gdb/linux/cpus.py b/scripts/gdb/linux/cpus.py new file mode 100644 index 0000000..18337e0 --- /dev/null +++ b/scripts/gdb/linux/cpus.py @@ -0,0 +1,68 @@ +# +# gdb helper commands and functions for Linux kernel debugging +# +# per-cpu tools +# +# Copyright (c) Siemens AG, 2011-2013 +# +# Authors: +# Jan Kiszka +# +# This work is licensed under the terms of the GNU GPL version 2. +# + +import gdb + +from linux import tasks, utils + + +MAX_CPUS = 4096 + + +def get_current_cpu(): + if utils.get_gdbserver_type() == utils.GDBSERVER_QEMU: + return gdb.selected_thread().num - 1 + elif utils.get_gdbserver_type() == utils.GDBSERVER_KGDB: + tid = gdb.selected_thread().ptid[2] + if tid > (0x100000000 - MAX_CPUS - 2): + return 0x100000000 - tid - 2 + else: + return tasks.get_thread_info(tasks.get_task_by_pid(tid))['cpu'] + else: + raise gdb.GdbError("Sorry, obtaining the current CPU is not yet " + "supported with this gdb server.") + + +def per_cpu(var_ptr, cpu): + if cpu == -1: + cpu = get_current_cpu() + if utils.is_target_arch("sparc:v9"): + offset = gdb.parse_and_eval( + "trap_block[{0}].__per_cpu_base".format(str(cpu))) + else: + try: + offset = gdb.parse_and_eval( + "__per_cpu_offset[{0}]".format(str(cpu))) + except gdb.error: + # !CONFIG_SMP case + offset = 0 + pointer = var_ptr.cast(utils.get_long_type()) + offset + return pointer.cast(var_ptr.type).dereference() + + +class PerCpu(gdb.Function): + """Return per-cpu variable. + +$lx_per_cpu("VAR"[, CPU]): Return the per-cpu variable called VAR for the +given CPU number. If CPU is omitted, the CPU of the current context is used. +Note that VAR has to be quoted as string.""" + + def __init__(self): + super(PerCpu, self).__init__("lx_per_cpu") + + def invoke(self, var_name, cpu=-1): + var_ptr = gdb.parse_and_eval("&" + var_name.string()) + return per_cpu(var_ptr, cpu) + + +PerCpu() diff --git a/scripts/gdb/vmlinux-gdb.py b/scripts/gdb/vmlinux-gdb.py index 4d7eb2c..4848928 100644 --- a/scripts/gdb/vmlinux-gdb.py +++ b/scripts/gdb/vmlinux-gdb.py @@ -27,3 +27,4 @@ else: import linux.modules import linux.dmesg import linux.tasks + import linux.cpus -- 1.8.1.1.298.ge7eed54 -- 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/