From mboxrd@z Thu Jan 1 00:00:00 1970 From: Borislav Petkov Date: Tue, 29 Jan 2013 13:51:09 +0000 Subject: Re: [PATCH v5 16/20] scripts/gdb: Add internal helper and convenience function for per-cpu lookup Message-Id: <20130129135109.GF14302@pd.tnic> List-Id: References: <04960fa208fbd9c0962eb4f70aa45d28aec59e8d.1359463075.git.jan.kiszka@siemens.com> In-Reply-To: <04960fa208fbd9c0962eb4f70aa45d28aec59e8d.1359463075.git.jan.kiszka@siemens.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Jan Kiszka Cc: Andrew Morton , linux-kernel@vger.kernel.org, Jason Wessel , kgdb-bugreport@lists.sourceforge.net, Andi Kleen , Tom Tromey , Ben Widawsky , "David S. Miller" , sparclinux@vger.kernel.org On Tue, Jan 29, 2013 at 01:37:59PM +0100, Jan Kiszka wrote: > 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/percpu.py | 61 ++++++++++++++++++++++++++++++++++++++++++++ > scripts/gdb/vmlinux-gdb.py | 1 + > 2 files changed, 62 insertions(+), 0 deletions(-) > create mode 100644 scripts/gdb/percpu.py > > diff --git a/scripts/gdb/percpu.py b/scripts/gdb/percpu.py > new file mode 100644 > index 0000000..864962c > --- /dev/null > +++ b/scripts/gdb/percpu.py > @@ -0,0 +1,61 @@ > +# > +# gdb helper commands and functions for Linux kernel debugging > +# > +# per-cpu tools This is actually a very cool thing for CPU guys: it can show what kind of hybrid CPUs they've been glueing together, like the following, for example: ... (gdb) p $lx_per_cpu("cpu_info").x86_virt_bits $5 = 48 '0' (gdb) p $lx_per_cpu("cpu_info").x86_vendor_id $6 = "GenuineIntel\000\000\000" (gdb) p $lx_per_cpu("cpu_info").x86_model_id $7 = "AMD Phenom(tm) 9550 Quad-Core Processor", '\000' (gdb) Since when does Intel produce CPUs called "AMD Phenom(tm) 9550 Quad-Core Processor"? .. hahaha.. > +# > +# Copyright (c) Siemens AG, 2011-2013 > +# > +# Authors: > +# Jan Kiszka > +# > +# This work is licensed under the terms of the GNU GPL version 2. > +# > + > +import gdb > + > +from utils import * > +from task import * > + > +MAX_CPUS = 4096 > + > +def get_current_cpu(): > + if get_gdbserver_type() = GDBSERVER_QEMU: > + return gdb.selected_thread().num - 1 > + elif get_gdbserver_type() = GDBSERVER_KGDB: > + tid = gdb.selected_thread().ptid[2] > + if tid > (0x100000000 - MAX_CPUS - 2): > + return 0x100000000 - tid - 2 > + else: > + return get_thread_info(get_task_by_pid(tid))['cpu'] > + else: > + raise gdb.GdbError("Sorry, obtaining the current CPU is " > + "not yet supported with this gdb server.") > + > +def per_cpu(var_ptr, cpu): > + if cpu = -1: > + cpu = get_current_cpu() > + if is_target_arch("sparc:v9"): > + offset = gdb.parse_and_eval("trap_block[" + str(cpu) + > + "].__per_cpu_base") > + else: > + offset = gdb.parse_and_eval("__per_cpu_offset[" + str(cpu) + > + "]") > + pointer = var_ptr.cast(get_long_type()) + offset > + return pointer.cast(var_ptr.type).dereference() > + > + > +class PerCpu(gdb.Function): > + __doc__ = "Return per-cpu variable.\n" \ > + "\n" \ > + "$lx_per_cpu(\"VAR\"[, CPU]): Return the per-cpu variable called VAR for the\n" \ > + "given CPU number. If CPU is omitted, the CPU of the current context is used.\n" \ > + "Note that VAR has to be quoted as string." Ok, seriously now: apropos shows the "Return per-cpu... " line above. Have you found out which gdb command shows the rest? help and info both say "Undefined command". Thanks. -- Regards/Gruss, Boris. Sent from a fat crate under my desk. Formatting is fine. -- From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756906Ab3A2NvQ (ORCPT ); Tue, 29 Jan 2013 08:51:16 -0500 Received: from mail.skyhub.de ([78.46.96.112]:40196 "EHLO mail.skyhub.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755361Ab3A2NvN (ORCPT ); Tue, 29 Jan 2013 08:51:13 -0500 Date: Tue, 29 Jan 2013 14:51:09 +0100 From: Borislav Petkov To: Jan Kiszka Cc: Andrew Morton , linux-kernel@vger.kernel.org, Jason Wessel , kgdb-bugreport@lists.sourceforge.net, Andi Kleen , Tom Tromey , Ben Widawsky , "David S. Miller" , sparclinux@vger.kernel.org Subject: Re: [PATCH v5 16/20] scripts/gdb: Add internal helper and convenience function for per-cpu lookup Message-ID: <20130129135109.GF14302@pd.tnic> Mail-Followup-To: Borislav Petkov , Jan Kiszka , Andrew Morton , linux-kernel@vger.kernel.org, Jason Wessel , kgdb-bugreport@lists.sourceforge.net, Andi Kleen , Tom Tromey , Ben Widawsky , "David S. Miller" , sparclinux@vger.kernel.org References: <04960fa208fbd9c0962eb4f70aa45d28aec59e8d.1359463075.git.jan.kiszka@siemens.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <04960fa208fbd9c0962eb4f70aa45d28aec59e8d.1359463075.git.jan.kiszka@siemens.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jan 29, 2013 at 01:37:59PM +0100, Jan Kiszka wrote: > 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/percpu.py | 61 ++++++++++++++++++++++++++++++++++++++++++++ > scripts/gdb/vmlinux-gdb.py | 1 + > 2 files changed, 62 insertions(+), 0 deletions(-) > create mode 100644 scripts/gdb/percpu.py > > diff --git a/scripts/gdb/percpu.py b/scripts/gdb/percpu.py > new file mode 100644 > index 0000000..864962c > --- /dev/null > +++ b/scripts/gdb/percpu.py > @@ -0,0 +1,61 @@ > +# > +# gdb helper commands and functions for Linux kernel debugging > +# > +# per-cpu tools This is actually a very cool thing for CPU guys: it can show what kind of hybrid CPUs they've been glueing together, like the following, for example: ... (gdb) p $lx_per_cpu("cpu_info").x86_virt_bits $5 = 48 '0' (gdb) p $lx_per_cpu("cpu_info").x86_vendor_id $6 = "GenuineIntel\000\000\000" (gdb) p $lx_per_cpu("cpu_info").x86_model_id $7 = "AMD Phenom(tm) 9550 Quad-Core Processor", '\000' (gdb) Since when does Intel produce CPUs called "AMD Phenom(tm) 9550 Quad-Core Processor"? .. hahaha.. > +# > +# Copyright (c) Siemens AG, 2011-2013 > +# > +# Authors: > +# Jan Kiszka > +# > +# This work is licensed under the terms of the GNU GPL version 2. > +# > + > +import gdb > + > +from utils import * > +from task import * > + > +MAX_CPUS = 4096 > + > +def get_current_cpu(): > + if get_gdbserver_type() == GDBSERVER_QEMU: > + return gdb.selected_thread().num - 1 > + elif get_gdbserver_type() == GDBSERVER_KGDB: > + tid = gdb.selected_thread().ptid[2] > + if tid > (0x100000000 - MAX_CPUS - 2): > + return 0x100000000 - tid - 2 > + else: > + return get_thread_info(get_task_by_pid(tid))['cpu'] > + else: > + raise gdb.GdbError("Sorry, obtaining the current CPU is " > + "not yet supported with this gdb server.") > + > +def per_cpu(var_ptr, cpu): > + if cpu == -1: > + cpu = get_current_cpu() > + if is_target_arch("sparc:v9"): > + offset = gdb.parse_and_eval("trap_block[" + str(cpu) + > + "].__per_cpu_base") > + else: > + offset = gdb.parse_and_eval("__per_cpu_offset[" + str(cpu) + > + "]") > + pointer = var_ptr.cast(get_long_type()) + offset > + return pointer.cast(var_ptr.type).dereference() > + > + > +class PerCpu(gdb.Function): > + __doc__ = "Return per-cpu variable.\n" \ > + "\n" \ > + "$lx_per_cpu(\"VAR\"[, CPU]): Return the per-cpu variable called VAR for the\n" \ > + "given CPU number. If CPU is omitted, the CPU of the current context is used.\n" \ > + "Note that VAR has to be quoted as string." Ok, seriously now: apropos shows the "Return per-cpu... " line above. Have you found out which gdb command shows the rest? help and info both say "Undefined command". Thanks. -- Regards/Gruss, Boris. Sent from a fat crate under my desk. Formatting is fine. --