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Merge git://git.kernel.org/pub/scm/linux/kernel/git/mingo/linux-2.6-kgdb 

* git://git.kernel.org/pub/scm/linux/kernel/git/mingo/linux-2.6-kgdb:
  kgdb: always use icache flush for sw breakpoints
  kgdb: fix SMP NMI kgdb_handle_exception exit race
  kgdb: documentation fixes
  kgdb: allow static kgdbts boot configuration
  kgdb: add documentation
  kgdb: Kconfig fix
  kgdb: add kgdb internal test suite
  kgdb: fix several kgdb regressions
  kgdb: kgdboc pl011 I/O module
  kgdb: fix optional arch functions and probe_kernel_*
  kgdb: add x86 HW breakpoints
  kgdb: print breakpoint removed on exception
  kgdb: clocksource watchdog
  kgdb: fix NMI hangs
  kgdb: fix kgdboc dynamic module configuration
  kgdb: document parameters
  x86: kgdb support
  consoles: polling support, kgdboc
  kgdb: core
  uaccess: add probe_kernel_write()
This commit is contained in:
Linus Torvalds 2008-04-18 08:37:01 -07:00
parent 9e9abecfc0 1a9a3e76dd
commit 9732b61123
33 changed files with 4757 additions and 7 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
Documentation/DocBook/Makefile
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@ -9,7 +9,7 @@
DOCBOOKS := wanbook.xml z8530book.xml mcabook.xml videobook.xml \
kernel-hacking.xml kernel-locking.xml deviceiobook.xml \
procfs-guide.xml writing_usb_driver.xml networking.xml \
kernel-api.xml filesystems.xml lsm.xml usb.xml \
kernel-api.xml filesystems.xml lsm.xml usb.xml kgdb.xml \
gadget.xml libata.xml mtdnand.xml librs.xml rapidio.xml \
genericirq.xml s390-drivers.xml uio-howto.xml scsi.xml

447
Documentation/DocBook/kgdb.tmpl Normal file
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@ -0,0 +1,447 @@
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook XML V4.1.2//EN"
"http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd" []>
<book id="kgdbOnLinux">
<bookinfo>
<title>Using kgdb and the kgdb Internals</title>
<authorgroup>
<author>
<firstname>Jason</firstname>
<surname>Wessel</surname>
<affiliation>
<address>
<email>jason.wessel@windriver.com</email>
</address>
</affiliation>
</author>
</authorgroup>
<authorgroup>
<author>
<firstname>Tom</firstname>
<surname>Rini</surname>
<affiliation>
<address>
<email>trini@kernel.crashing.org</email>
</address>
</affiliation>
</author>
</authorgroup>
<authorgroup>
<author>
<firstname>Amit S.</firstname>
<surname>Kale</surname>
<affiliation>
<address>
<email>amitkale@linsyssoft.com</email>
</address>
</affiliation>
</author>
</authorgroup>
<copyright>
<year>2008</year>
<holder>Wind River Systems, Inc.</holder>
</copyright>
<copyright>
<year>2004-2005</year>
<holder>MontaVista Software, Inc.</holder>
</copyright>
<copyright>
<year>2004</year>
<holder>Amit S. Kale</holder>
</copyright>
<legalnotice>
<para>
This file is licensed under the terms of the GNU General Public License
version 2. This program is licensed "as is" without any warranty of any
kind, whether express or implied.
</para>
</legalnotice>
</bookinfo>
<toc></toc>
<chapter id="Introduction">
<title>Introduction</title>
<para>
kgdb is a source level debugger for linux kernel. It is used along
with gdb to debug a linux kernel. The expectation is that gdb can
be used to "break in" to the kernel to inspect memory, variables
and look through a cal stack information similar to what an
application developer would use gdb for. It is possible to place
breakpoints in kernel code and perform some limited execution
stepping.
</para>
<para>
Two machines are required for using kgdb. One of these machines is a
development machine and the other is a test machine. The kernel
to be debugged runs on the test machine. The development machine
runs an instance of gdb against the vmlinux file which contains
the symbols (not boot image such as bzImage, zImage, uImage...).
In gdb the developer specifies the connection parameters and
connects to kgdb. Depending on which kgdb I/O modules exist in
the kernel for a given architecture, it may be possible to debug
the test machine's kernel with the development machine using a
rs232 or ethernet connection.
</para>
</chapter>
<chapter id="CompilingAKernel">
<title>Compiling a kernel</title>
<para>
To enable <symbol>CONFIG_KGDB</symbol>, look under the "Kernel debugging"
and then select "KGDB: kernel debugging with remote gdb".
</para>
<para>
Next you should choose one of more I/O drivers to interconnect debugging
host and debugged target. Early boot debugging requires a KGDB
I/O driver that supports early debugging and the driver must be
built into the kernel directly. Kgdb I/O driver configuration
takes place via kernel or module parameters, see following
chapter.
</para>
<para>
The kgdb test compile options are described in the kgdb test suite chapter.
</para>
</chapter>
<chapter id="EnableKGDB">
<title>Enable kgdb for debugging</title>
<para>
In order to use kgdb you must activate it by passing configuration
information to one of the kgdb I/O drivers. If you do not pass any
configuration information kgdb will not do anything at all. Kgdb
will only actively hook up to the kernel trap hooks if a kgdb I/O
driver is loaded and configured. If you unconfigure a kgdb I/O
driver, kgdb will unregister all the kernel hook points.
</para>
<para>
All drivers can be reconfigured at run time, if
<symbol>CONFIG_SYSFS</symbol> and <symbol>CONFIG_MODULES</symbol>
are enabled, by echo'ing a new config string to
<constant>/sys/module/&lt;driver&gt;/parameter/&lt;option&gt;</constant>.
The driver can be unconfigured by passing an empty string. You cannot
change the configuration while the debugger is attached. Make sure
to detach the debugger with the <constant>detach</constant> command
prior to trying unconfigure a kgdb I/O driver.
</para>
<sect1 id="kgdbwait">
<title>Kernel parameter: kgdbwait</title>
<para>
The Kernel command line option <constant>kgdbwait</constant> makes
kgdb wait for a debugger connection during booting of a kernel. You
can only use this option you compiled a kgdb I/O driver into the
kernel and you specified the I/O driver configuration as a kernel
command line option. The kgdbwait parameter should always follow the
configuration parameter for the kgdb I/O driver in the kernel
command line else the I/O driver will not be configured prior to
asking the kernel to use it to wait.
</para>
<para>
The kernel will stop and wait as early as the I/O driver and
architecture will allow when you use this option. If you build the
kgdb I/O driver as a kernel module kgdbwait will not do anything.
</para>
</sect1>
<sect1 id="kgdboc">
<title>Kernel parameter: kgdboc</title>
<para>
The kgdboc driver was originally an abbreviation meant to stand for
"kgdb over console". Kgdboc is designed to work with a single
serial port. It was meant to cover the circumstance
where you wanted to use a serial console as your primary console as
well as using it to perform kernel debugging. Of course you can
also use kgdboc without assigning a console to the same port.
</para>
<sect2 id="UsingKgdboc">
<title>Using kgdboc</title>
<para>
You can configure kgdboc via sysfs or a module or kernel boot line
parameter depending on if you build with CONFIG_KGDBOC as a module
or built-in.
<orderedlist>
<listitem><para>From the module load or build-in</para>
<para><constant>kgdboc=&lt;tty-device&gt;,[baud]</constant></para>
<para>
The example here would be if your console port was typically ttyS0, you would use something like <constant>kgdboc=ttyS0,115200</constant> or on the ARM Versatile AB you would likely use <constant>kgdboc=ttyAMA0,115200</constant>
</para>
</listitem>
<listitem><para>From sysfs</para>
<para><constant>echo ttyS0 &gt; /sys/module/kgdboc/parameters/kgdboc</constant></para>
</listitem>
</orderedlist>
</para>
<para>
NOTE: Kgdboc does not support interrupting the target via the
gdb remote protocol. You must manually send a sysrq-g unless you
have a proxy that splits console output to a terminal problem and
has a separate port for the debugger to connect to that sends the
sysrq-g for you.
</para>
<para>When using kgdboc with no debugger proxy, you can end up
connecting the debugger for one of two entry points. If an
exception occurs after you have loaded kgdboc a message should print
on the console stating it is waiting for the debugger. In case you
disconnect your terminal program and then connect the debugger in
its place. If you want to interrupt the target system and forcibly
enter a debug session you have to issue a Sysrq sequence and then
type the letter <constant>g</constant>. Then you disconnect the
terminal session and connect gdb. Your options if you don't like
this are to hack gdb to send the sysrq-g for you as well as on the
initial connect, or to use a debugger proxy that allows an
unmodified gdb to do the debugging.
</para>
</sect2>
</sect1>
<sect1 id="kgdbcon">
<title>Kernel parameter: kgdbcon</title>
<para>
Kgdb supports using the gdb serial protocol to send console messages
to the debugger when the debugger is connected and running. There
are two ways to activate this feature.
<orderedlist>
<listitem><para>Activate with the kernel command line option:</para>
<para><constant>kgdbcon</constant></para>
</listitem>
<listitem><para>Use sysfs before configuring an io driver</para>
<para>
<constant>echo 1 &gt; /sys/module/kgdb/parameters/kgdb_use_con</constant>
</para>
<para>
NOTE: If you do this after you configure the kgdb I/O driver, the
setting will not take effect until the next point the I/O is
reconfigured.
</para>
</listitem>
</orderedlist>
</para>
<para>
IMPORTANT NOTE: Using this option with kgdb over the console
(kgdboc) or kgdb over ethernet (kgdboe) is not supported.
</para>
</sect1>
</chapter>
<chapter id="ConnectingGDB">
<title>Connecting gdb</title>
<para>
If you are using kgdboc, you need to have used kgdbwait as a boot
argument, issued a sysrq-g, or the system you are going to debug
has already taken an exception and is waiting for the debugger to
attach before you can connect gdb.
</para>
<para>
If you are not using different kgdb I/O driver other than kgdboc,
you should be able to connect and the target will automatically
respond.
</para>
<para>
Example (using a serial port):
</para>
<programlisting>
% gdb ./vmlinux
(gdb) set remotebaud 115200
(gdb) target remote /dev/ttyS0
</programlisting>
<para>
Example (kgdb to a terminal server):
</para>
<programlisting>
% gdb ./vmlinux
(gdb) target remote udp:192.168.2.2:6443
</programlisting>
<para>
Example (kgdb over ethernet):
</para>
<programlisting>
% gdb ./vmlinux
(gdb) target remote udp:192.168.2.2:6443
</programlisting>
<para>
Once connected, you can debug a kernel the way you would debug an
application program.
</para>
<para>
If you are having problems connecting or something is going
seriously wrong while debugging, it will most often be the case
that you want to enable gdb to be verbose about its target
communications. You do this prior to issuing the <constant>target
remote</constant> command by typing in: <constant>set remote debug 1</constant>
</para>
</chapter>
<chapter id="KGDBTestSuite">
<title>kgdb Test Suite</title>
<para>
When kgdb is enabled in the kernel config you can also elect to
enable the config parameter KGDB_TESTS. Turning this on will
enable a special kgdb I/O module which is designed to test the
kgdb internal functions.
</para>
<para>
The kgdb tests are mainly intended for developers to test the kgdb
internals as well as a tool for developing a new kgdb architecture
specific implementation. These tests are not really for end users
of the Linux kernel. The primary source of documentation would be
to look in the drivers/misc/kgdbts.c file.
</para>
<para>
The kgdb test suite can also be configured at compile time to run
the core set of tests by setting the kernel config parameter
KGDB_TESTS_ON_BOOT. This particular option is aimed at automated
regression testing and does not require modifying the kernel boot
config arguments. If this is turned on, the kgdb test suite can
be disabled by specifying "kgdbts=" as a kernel boot argument.
</para>
</chapter>
<chapter id="CommonBackEndReq">
<title>KGDB Internals</title>
<sect1 id="kgdbArchitecture">
<title>Architecture Specifics</title>
<para>
Kgdb is organized into three basic components:
<orderedlist>
<listitem><para>kgdb core</para>
<para>
The kgdb core is found in kernel/kgdb.c. It contains:
<itemizedlist>
<listitem><para>All the logic to implement the gdb serial protocol</para></listitem>
<listitem><para>A generic OS exception handler which includes sync'ing the processors into a stopped state on an multi cpu system.</para></listitem>
<listitem><para>The API to talk to the kgdb I/O drivers</para></listitem>
<listitem><para>The API to make calls to the arch specific kgdb implementation</para></listitem>
<listitem><para>The logic to perform safe memory reads and writes to memory while using the debugger</para></listitem>
<listitem><para>A full implementation for software breakpoints unless overridden by the arch</para></listitem>
</itemizedlist>
</para>
</listitem>
<listitem><para>kgdb arch specific implementation</para>
<para>
This implementation is generally found in arch/*/kernel/kgdb.c.
As an example, arch/x86/kernel/kgdb.c contains the specifics to
implement HW breakpoint as well as the initialization to
dynamically register and unregister for the trap handlers on
this architecture. The arch specific portion implements:
<itemizedlist>
<listitem><para>contains an arch specific trap catcher which
invokes kgdb_handle_exception() to start kgdb about doing its
work</para></listitem>
<listitem><para>translation to and from gdb specific packet format to pt_regs</para></listitem>
<listitem><para>Registration and unregistration of architecture specific trap hooks</para></listitem>
<listitem><para>Any special exception handling and cleanup</para></listitem>
<listitem><para>NMI exception handling and cleanup</para></listitem>
<listitem><para>(optional)HW breakpoints</para></listitem>
</itemizedlist>
</para>
</listitem>
<listitem><para>kgdb I/O driver</para>
<para>
Each kgdb I/O driver has to provide an implemenation for the following:
<itemizedlist>
<listitem><para>configuration via builtin or module</para></listitem>
<listitem><para>dynamic configuration and kgdb hook registration calls</para></listitem>
<listitem><para>read and write character interface</para></listitem>
<listitem><para>A cleanup handler for unconfiguring from the kgdb core</para></listitem>
<listitem><para>(optional) Early debug methodology</para></listitem>
</itemizedlist>
Any given kgdb I/O driver has to operate very closely with the
hardware and must do it in such a way that does not enable
interrupts or change other parts of the system context without
completely restoring them. The kgdb core will repeatedly "poll"
a kgdb I/O driver for characters when it needs input. The I/O
driver is expected to return immediately if there is no data
available. Doing so allows for the future possibility to touch
watch dog hardware in such a way as to have a target system not
reset when these are enabled.
</para>
</listitem>
</orderedlist>
</para>
<para>
If you are intent on adding kgdb architecture specific support
for a new architecture, the architecture should define
<constant>HAVE_ARCH_KGDB</constant> in the architecture specific
Kconfig file. This will enable kgdb for the architecture, and
at that point you must create an architecture specific kgdb
implementation.
</para>
<para>
There are a few flags which must be set on every architecture in
their &lt;asm/kgdb.h&gt; file. These are:
<itemizedlist>
<listitem>
<para>
NUMREGBYTES: The size in bytes of all of the registers, so
that we can ensure they will all fit into a packet.
</para>
<para>
BUFMAX: The size in bytes of the buffer GDB will read into.
This must be larger than NUMREGBYTES.
</para>
<para>
CACHE_FLUSH_IS_SAFE: Set to 1 if it is always safe to call
flush_cache_range or flush_icache_range. On some architectures,
these functions may not be safe to call on SMP since we keep other
CPUs in a holding pattern.
</para>
</listitem>
</itemizedlist>
</para>
<para>
There are also the following functions for the common backend,
found in kernel/kgdb.c, that must be supplied by the
architecture-specific backend unless marked as (optional), in
which case a default function maybe used if the architecture
does not need to provide a specific implementation.
</para>
!Iinclude/linux/kgdb.h
</sect1>
<sect1 id="kgdbocDesign">
<title>kgdboc internals</title>
<para>
The kgdboc driver is actually a very thin driver that relies on the
underlying low level to the hardware driver having "polling hooks"
which the to which the tty driver is attached. In the initial
implementation of kgdboc it the serial_core was changed to expose a
low level uart hook for doing polled mode reading and writing of a
single character while in an atomic context. When kgdb makes an I/O
request to the debugger, kgdboc invokes a call back in the serial
core which in turn uses the call back in the uart driver. It is
certainly possible to extend kgdboc to work with non-uart based
consoles in the future.
</para>
<para>
When using kgdboc with a uart, the uart driver must implement two callbacks in the <constant>struct uart_ops</constant>. Example from drivers/8250.c:<programlisting>
#ifdef CONFIG_CONSOLE_POLL
.poll_get_char = serial8250_get_poll_char,
.poll_put_char = serial8250_put_poll_char,
#endif
</programlisting>
Any implementation specifics around creating a polling driver use the
<constant>#ifdef CONFIG_CONSOLE_POLL</constant>, as shown above.
Keep in mind that polling hooks have to be implemented in such a way
that they can be called from an atomic context and have to restore
the state of the uart chip on return such that the system can return
to normal when the debugger detaches. You need to be very careful
with any kind of lock you consider, because failing here is most
going to mean pressing the reset button.
</para>
</sect1>
</chapter>
<chapter id="credits">
<title>Credits</title>
<para>
The following people have contributed to this document:
<orderedlist>
<listitem><para>Amit Kale<email>amitkale@linsyssoft.com</email></para></listitem>
<listitem><para>Tom Rini<email>trini@kernel.crashing.org</email></para></listitem>
</orderedlist>
In March 2008 this document was completely rewritten by:
<itemizedlist>
<listitem><para>Jason Wessel<email>jason.wessel@windriver.com</email></para></listitem>
</itemizedlist>
</para>
</chapter>
</book>

5
Documentation/kernel-parameters.txt
View File

@ -941,6 +941,11 @@ and is between 256 and 4096 characters. It is defined in the file
kstack=N [X86-32,X86-64] Print N words from the kernel stack
in oops dumps.
kgdboc= [HW] kgdb over consoles.
Requires a tty driver that supports console polling.
(only serial suported for now)
Format: <serial_device>[,baud]
l2cr= [PPC]
lapic [X86-32,APIC] Enable the local APIC even if BIOS

6
MAINTAINERS
View File

@ -2319,6 +2319,12 @@ L: linux-kernel@vger.kernel.org
L: kexec@lists.infradead.org
S: Maintained
KGDB
P: Jason Wessel
M: jason.wessel@windriver.com
L: kgdb-bugreport@lists.sourceforge.net
S: Maintained
KPROBES
P: Ananth N Mavinakayanahalli
M: ananth@in.ibm.com

1
arch/x86/Kconfig
View File

@ -23,6 +23,7 @@ config X86
select HAVE_KPROBES
select HAVE_KRETPROBES
select HAVE_KVM if ((X86_32 && !X86_VOYAGER && !X86_VISWS && !X86_NUMAQ) || X86_64)
select HAVE_ARCH_KGDB
config GENERIC_LOCKBREAK

1
arch/x86/kernel/Makefile
View File

@ -67,6 +67,7 @@ obj-$(CONFIG_MODULES) += module_$(BITS).o
obj-$(CONFIG_ACPI_SRAT) += srat_32.o
obj-$(CONFIG_EFI) += efi.o efi_$(BITS).o efi_stub_$(BITS).o
obj-$(CONFIG_DOUBLEFAULT) += doublefault_32.o
obj-$(CONFIG_KGDB) += kgdb.o
obj-$(CONFIG_VM86) += vm86_32.o
obj-$(CONFIG_EARLY_PRINTK) += early_printk.o

571
arch/x86/kernel/kgdb.c Normal file
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@ -0,0 +1,571 @@
/*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the
* Free Software Foundation; either version 2, or (at your option) any
* later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
*/
/*
* Copyright (C) 2004 Amit S. Kale <amitkale@linsyssoft.com>
* Copyright (C) 2000-2001 VERITAS Software Corporation.
* Copyright (C) 2002 Andi Kleen, SuSE Labs
* Copyright (C) 2004 LinSysSoft Technologies Pvt. Ltd.
* Copyright (C) 2007 MontaVista Software, Inc.
* Copyright (C) 2007-2008 Jason Wessel, Wind River Systems, Inc.
*/
/****************************************************************************
* Contributor: Lake Stevens Instrument Division$
* Written by: Glenn Engel $
* Updated by: Amit Kale<akale@veritas.com>
* Updated by: Tom Rini <trini@kernel.crashing.org>
* Updated by: Jason Wessel <jason.wessel@windriver.com>
* Modified for 386 by Jim Kingdon, Cygnus Support.
* Origianl kgdb, compatibility with 2.1.xx kernel by
* David Grothe <dave@gcom.com>
* Integrated into 2.2.5 kernel by Tigran Aivazian <tigran@sco.com>
* X86_64 changes from Andi Kleen's patch merged by Jim Houston
*/
#include <linux/spinlock.h>
#include <linux/kdebug.h>
#include <linux/string.h>
#include <linux/kernel.h>
#include <linux/ptrace.h>
#include <linux/sched.h>
#include <linux/delay.h>
#include <linux/kgdb.h>
#include <linux/init.h>
#include <linux/smp.h>
#include <linux/nmi.h>
#include <asm/apicdef.h>
#include <asm/system.h>
#ifdef CONFIG_X86_32
# include <mach_ipi.h>
#else
# include <asm/mach_apic.h>
#endif
/*
* Put the error code here just in case the user cares:
*/
static int gdb_x86errcode;
/*
* Likewise, the vector number here (since GDB only gets the signal
* number through the usual means, and that's not very specific):
*/
static int gdb_x86vector = -1;
/**
* pt_regs_to_gdb_regs - Convert ptrace regs to GDB regs
* @gdb_regs: A pointer to hold the registers in the order GDB wants.
* @regs: The &struct pt_regs of the current process.
*
* Convert the pt_regs in @regs into the format for registers that
* GDB expects, stored in @gdb_regs.
*/
void pt_regs_to_gdb_regs(unsigned long *gdb_regs, struct pt_regs *regs)
{
gdb_regs[GDB_AX] = regs->ax;
gdb_regs[GDB_BX] = regs->bx;
gdb_regs[GDB_CX] = regs->cx;
gdb_regs[GDB_DX] = regs->dx;
gdb_regs[GDB_SI] = regs->si;
gdb_regs[GDB_DI] = regs->di;
gdb_regs[GDB_BP] = regs->bp;
gdb_regs[GDB_PS] = regs->flags;
gdb_regs[GDB_PC] = regs->ip;
#ifdef CONFIG_X86_32
gdb_regs[GDB_DS] = regs->ds;
gdb_regs[GDB_ES] = regs->es;
gdb_regs[GDB_CS] = regs->cs;
gdb_regs[GDB_SS] = __KERNEL_DS;
gdb_regs[GDB_FS] = 0xFFFF;
gdb_regs[GDB_GS] = 0xFFFF;
#else
gdb_regs[GDB_R8] = regs->r8;
gdb_regs[GDB_R9] = regs->r9;
gdb_regs[GDB_R10] = regs->r10;
gdb_regs[GDB_R11] = regs->r11;
gdb_regs[GDB_R12] = regs->r12;
gdb_regs[GDB_R13] = regs->r13;
gdb_regs[GDB_R14] = regs->r14;
gdb_regs[GDB_R15] = regs->r15;
#endif
gdb_regs[GDB_SP] = regs->sp;
}
/**
* sleeping_thread_to_gdb_regs - Convert ptrace regs to GDB regs
* @gdb_regs: A pointer to hold the registers in the order GDB wants.
* @p: The &struct task_struct of the desired process.
*
* Convert the register values of the sleeping process in @p to
* the format that GDB expects.
* This function is called when kgdb does not have access to the
* &struct pt_regs and therefore it should fill the gdb registers
* @gdb_regs with what has been saved in &struct thread_struct
* thread field during switch_to.
*/
void sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, struct task_struct *p)
{
gdb_regs[GDB_AX] = 0;
gdb_regs[GDB_BX] = 0;
gdb_regs[GDB_CX] = 0;
gdb_regs[GDB_DX] = 0;
gdb_regs[GDB_SI] = 0;
gdb_regs[GDB_DI] = 0;
gdb_regs[GDB_BP] = *(unsigned long *)p->thread.sp;
#ifdef CONFIG_X86_32
gdb_regs[GDB_DS] = __KERNEL_DS;
gdb_regs[GDB_ES] = __KERNEL_DS;
gdb_regs[GDB_PS] = 0;
gdb_regs[GDB_CS] = __KERNEL_CS;
gdb_regs[GDB_PC] = p->thread.ip;
gdb_regs[GDB_SS] = __KERNEL_DS;
gdb_regs[GDB_FS] = 0xFFFF;
gdb_regs[GDB_GS] = 0xFFFF;
#else
gdb_regs[GDB_PS] = *(unsigned long *)(p->thread.sp + 8);
gdb_regs[GDB_PC] = 0;
gdb_regs[GDB_R8] = 0;
gdb_regs[GDB_R9] = 0;
gdb_regs[GDB_R10] = 0;
gdb_regs[GDB_R11] = 0;
gdb_regs[GDB_R12] = 0;
gdb_regs[GDB_R13] = 0;
gdb_regs[GDB_R14] = 0;
gdb_regs[GDB_R15] = 0;
#endif
gdb_regs[GDB_SP] = p->thread.sp;
}
/**
* gdb_regs_to_pt_regs - Convert GDB regs to ptrace regs.
* @gdb_regs: A pointer to hold the registers we've received from GDB.
* @regs: A pointer to a &struct pt_regs to hold these values in.
*
* Convert the GDB regs in @gdb_regs into the pt_regs, and store them
* in @regs.
*/
void gdb_regs_to_pt_regs(unsigned long *gdb_regs, struct pt_regs *regs)
{
regs->ax = gdb_regs[GDB_AX];
regs->bx = gdb_regs[GDB_BX];
regs->cx = gdb_regs[GDB_CX];
regs->dx = gdb_regs[GDB_DX];
regs->si = gdb_regs[GDB_SI];
regs->di = gdb_regs[GDB_DI];
regs->bp = gdb_regs[GDB_BP];
regs->flags = gdb_regs[GDB_PS];
regs->ip = gdb_regs[GDB_PC];
#ifdef CONFIG_X86_32
regs->ds = gdb_regs[GDB_DS];
regs->es = gdb_regs[GDB_ES];
regs->cs = gdb_regs[GDB_CS];
#else
regs->r8 = gdb_regs[GDB_R8];
regs->r9 = gdb_regs[GDB_R9];
regs->r10 = gdb_regs[GDB_R10];
regs->r11 = gdb_regs[GDB_R11];
regs->r12 = gdb_regs[GDB_R12];
regs->r13 = gdb_regs[GDB_R13];
regs->r14 = gdb_regs[GDB_R14];
regs->r15 = gdb_regs[GDB_R15];
#endif
}
static struct hw_breakpoint {
unsigned enabled;
unsigned type;
unsigned len;
unsigned long addr;
} breakinfo[4];
static void kgdb_correct_hw_break(void)
{
unsigned long dr7;
int correctit = 0;
int breakbit;
int breakno;
get_debugreg(dr7, 7);
for (breakno = 0; breakno < 4; breakno++) {
breakbit = 2 << (breakno << 1);
if (!(dr7 & breakbit) && breakinfo[breakno].enabled) {
correctit = 1;
dr7 |= breakbit;
dr7 &= ~(0xf0000 << (breakno << 2));
dr7 |= ((breakinfo[breakno].len << 2) |
breakinfo[breakno].type) <<
((breakno << 2) + 16);
if (breakno >= 0 && breakno <= 3)
set_debugreg(breakinfo[breakno].addr, breakno);
} else {
if ((dr7 & breakbit) && !breakinfo[breakno].enabled) {
correctit = 1;
dr7 &= ~breakbit;
dr7 &= ~(0xf0000 << (breakno << 2));
}
}
}
if (correctit)
set_debugreg(dr7, 7);
}
static int
kgdb_remove_hw_break(unsigned long addr, int len, enum kgdb_bptype bptype)
{
int i;
for (i = 0; i < 4; i++)
if (breakinfo[i].addr == addr && breakinfo[i].enabled)
break;
if (i == 4)
return -1;
breakinfo[i].enabled = 0;
return 0;
}
static void kgdb_remove_all_hw_break(void)
{
int i;
for (i = 0; i < 4; i++)
memset(&breakinfo[i], 0, sizeof(struct hw_breakpoint));
}
static int
kgdb_set_hw_break(unsigned long addr, int len, enum kgdb_bptype bptype)
{
unsigned type;
int i;
for (i = 0; i < 4; i++)
if (!breakinfo[i].enabled)
break;
if (i == 4)
return -1;
switch (bptype) {
case BP_HARDWARE_BREAKPOINT:
type = 0;
len = 1;
break;
case BP_WRITE_WATCHPOINT:
type = 1;
break;
case BP_ACCESS_WATCHPOINT:
type = 3;
break;
default:
return -1;
}
if (len == 1 || len == 2 || len == 4)
breakinfo[i].len = len - 1;
else
return -1;
breakinfo[i].enabled = 1;
breakinfo[i].addr = addr;
breakinfo[i].type = type;
return 0;
}
/**
* kgdb_disable_hw_debug - Disable hardware debugging while we in kgdb.
* @regs: Current &struct pt_regs.
*
* This function will be called if the particular architecture must
* disable hardware debugging while it is processing gdb packets or
* handling exception.
*/
void kgdb_disable_hw_debug(struct pt_regs *regs)
{
/* Disable hardware debugging while we are in kgdb: */
set_debugreg(0UL, 7);
}
/**
* kgdb_post_primary_code - Save error vector/code numbers.
* @regs: Original pt_regs.
* @e_vector: Original error vector.
* @err_code: Original error code.
*
* This is needed on architectures which support SMP and KGDB.
* This function is called after all the slave cpus have been put
* to a know spin state and the primary CPU has control over KGDB.
*/
void kgdb_post_primary_code(struct pt_regs *regs, int e_vector, int err_code)
{
/* primary processor is completely in the debugger */
gdb_x86vector = e_vector;
gdb_x86errcode = err_code;
}
#ifdef CONFIG_SMP
/**
* kgdb_roundup_cpus - Get other CPUs into a holding pattern
* @flags: Current IRQ state
*
* On SMP systems, we need to get the attention of the other CPUs
* and get them be in a known state. This should do what is needed
* to get the other CPUs to call kgdb_wait(). Note that on some arches,
* the NMI approach is not used for rounding up all the CPUs. For example,
* in case of MIPS, smp_call_function() is used to roundup CPUs. In
* this case, we have to make sure that interrupts are enabled before
* calling smp_call_function(). The argument to this function is
* the flags that will be used when restoring the interrupts. There is
* local_irq_save() call before kgdb_roundup_cpus().
*
* On non-SMP systems, this is not called.
*/
void kgdb_roundup_cpus(unsigned long flags)
{
send_IPI_allbutself(APIC_DM_NMI);
}
#endif
/**
* kgdb_arch_handle_exception - Handle architecture specific GDB packets.
* @vector: The error vector of the exception that happened.
* @signo: The signal number of the exception that happened.
* @err_code: The error code of the exception that happened.
* @remcom_in_buffer: The buffer of the packet we have read.
* @remcom_out_buffer: The buffer of %BUFMAX bytes to write a packet into.
* @regs: The &struct pt_regs of the current process.
*
* This function MUST handle the 'c' and 's' command packets,
* as well packets to set / remove a hardware breakpoint, if used.
* If there are additional packets which the hardware needs to handle,
* they are handled here. The code should return -1 if it wants to
* process more packets, and a %0 or %1 if it wants to exit from the
* kgdb callback.
*/
int kgdb_arch_handle_exception(int e_vector, int signo, int err_code,
char *remcomInBuffer, char *remcomOutBuffer,
struct pt_regs *linux_regs)
{
unsigned long addr;
unsigned long dr6;
char *ptr;
int newPC;
switch (remcomInBuffer[0]) {
case 'c':
case 's':
/* try to read optional parameter, pc unchanged if no parm */
ptr = &remcomInBuffer[1];
if (kgdb_hex2long(&ptr, &addr))
linux_regs->ip = addr;
case 'D':
case 'k':
newPC = linux_regs->ip;
/* clear the trace bit */
linux_regs->flags &= ~TF_MASK;
atomic_set(&kgdb_cpu_doing_single_step, -1);
/* set the trace bit if we're stepping */
if (remcomInBuffer[0] == 's') {
linux_regs->flags |= TF_MASK;
kgdb_single_step = 1;
if (kgdb_contthread) {
atomic_set(&kgdb_cpu_doing_single_step,
raw_smp_processor_id());
}
}
get_debugreg(dr6, 6);
if (!(dr6 & 0x4000)) {
int breakno;
for (breakno = 0; breakno < 4; breakno++) {
if (dr6 & (1 << breakno) &&
breakinfo[breakno].type == 0) {
/* Set restore flag: */
linux_regs->flags |= X86_EFLAGS_RF;
break;
}
}
}
set_debugreg(0UL, 6);
kgdb_correct_hw_break();
return 0;
}
/* this means that we do not want to exit from the handler: */
return -1;
}
static inline int
single_step_cont(struct pt_regs *regs, struct die_args *args)
{
/*
* Single step exception from kernel space to user space so
* eat the exception and continue the process:
*/
printk(KERN_ERR "KGDB: trap/step from kernel to user space, "
"resuming...\n");
kgdb_arch_handle_exception(args->trapnr, args->signr,
args->err, "c", "", regs);
return NOTIFY_STOP;
}
static int was_in_debug_nmi[NR_CPUS];
static int __kgdb_notify(struct die_args *args, unsigned long cmd)
{
struct pt_regs *regs = args->regs;
switch (cmd) {
case DIE_NMI:
if (atomic_read(&kgdb_active) != -1) {
/* KGDB CPU roundup */
kgdb_nmicallback(raw_smp_processor_id(), regs);
was_in_debug_nmi[raw_smp_processor_id()] = 1;
touch_nmi_watchdog();
return NOTIFY_STOP;
}
return NOTIFY_DONE;
case DIE_NMI_IPI:
if (atomic_read(&kgdb_active) != -1) {
/* KGDB CPU roundup */
kgdb_nmicallback(raw_smp_processor_id(), regs);
was_in_debug_nmi[raw_smp_processor_id()] = 1;
touch_nmi_watchdog();
}
return NOTIFY_DONE;
case DIE_NMIUNKNOWN:
if (was_in_debug_nmi[raw_smp_processor_id()]) {
was_in_debug_nmi[raw_smp_processor_id()] = 0;
return NOTIFY_STOP;
}
return NOTIFY_DONE;
case DIE_NMIWATCHDOG:
if (atomic_read(&kgdb_active) != -1) {
/* KGDB CPU roundup: */
kgdb_nmicallback(raw_smp_processor_id(), regs);
return NOTIFY_STOP;
}
/* Enter debugger: */
break;
case DIE_DEBUG:
if (atomic_read(&kgdb_cpu_doing_single_step) ==
raw_smp_processor_id() &&
user_mode(regs))
return single_step_cont(regs, args);
/* fall through */
default:
if (user_mode(regs))
return NOTIFY_DONE;
}
if (kgdb_handle_exception(args->trapnr, args->signr, args->err, regs))
return NOTIFY_DONE;
/* Must touch watchdog before return to normal operation */
touch_nmi_watchdog();
return NOTIFY_STOP;
}
static int
kgdb_notify(struct notifier_block *self, unsigned long cmd, void *ptr)
{
unsigned long flags;
int ret;
local_irq_save(flags);
ret = __kgdb_notify(ptr, cmd);
local_irq_restore(flags);
return ret;
}
static struct notifier_block kgdb_notifier = {
.notifier_call = kgdb_notify,
/*
* Lowest-prio notifier priority, we want to be notified last:
*/
.priority = -INT_MAX,
};
/**
* kgdb_arch_init - Perform any architecture specific initalization.
*
* This function will handle the initalization of any architecture
* specific callbacks.
*/
int kgdb_arch_init(void)
{
return register_die_notifier(&kgdb_notifier);
}
/**
* kgdb_arch_exit - Perform any architecture specific uninitalization.
*
* This function will handle the uninitalization of any architecture
* specific callbacks, for dynamic registration and unregistration.
*/
void kgdb_arch_exit(void)
{
unregister_die_notifier(&kgdb_notifier);
}
/**
*
* kgdb_skipexception - Bail out of KGDB when we've been triggered.
* @exception: Exception vector number
* @regs: Current &struct pt_regs.
*
* On some architectures we need to skip a breakpoint exception when
* it occurs after a breakpoint has been removed.
*
* Skip an int3 exception when it occurs after a breakpoint has been
* removed. Backtrack eip by 1 since the int3 would have caused it to
* increment by 1.
*/
int kgdb_skipexception(int exception, struct pt_regs *regs)
{
if (exception == 3 && kgdb_isremovedbreak(regs->ip - 1)) {
regs->ip -= 1;
return 1;
}
return 0;
}
unsigned long kgdb_arch_pc(int exception, struct pt_regs *regs)
{
if (exception == 3)
return instruction_pointer(regs) - 1;
return instruction_pointer(regs);
}
struct kgdb_arch arch_kgdb_ops = {
/* Breakpoint instruction: */
.gdb_bpt_instr = { 0xcc },
.flags = KGDB_HW_BREAKPOINT,
.set_hw_breakpoint = kgdb_set_hw_break,
.remove_hw_breakpoint = kgdb_remove_hw_break,
.remove_all_hw_break = kgdb_remove_all_hw_break,
.correct_hw_break = kgdb_correct_hw_break,
};

16
arch/x86/kernel/setup64.c
View File

@ -11,6 +11,7 @@
#include <linux/bootmem.h>
#include <linux/bitops.h>
#include <linux/module.h>
#include <linux/kgdb.h>
#include <asm/pda.h>
#include <asm/pgtable.h>
#include <asm/processor.h>
@ -251,6 +252,17 @@ void __cpuinit cpu_init (void)
load_TR_desc();
load_LDT(&init_mm.context);
#ifdef CONFIG_KGDB
/*
* If the kgdb is connected no debug regs should be altered. This
* is only applicable when KGDB and a KGDB I/O module are built
* into the kernel and you are using early debugging with
* kgdbwait. KGDB will control the kernel HW breakpoint registers.
*/
if (kgdb_connected && arch_kgdb_ops.correct_hw_break)
arch_kgdb_ops.correct_hw_break();
else {
#endif
/*
* Clear all 6 debug registers:
*/
@ -261,6 +273,10 @@ void __cpuinit cpu_init (void)
set_debugreg(0UL, 3);
set_debugreg(0UL, 6);
set_debugreg(0UL, 7);
#ifdef CONFIG_KGDB
/* If the kgdb is connected no debug regs should be altered. */
}
#endif
fpu_init();

2
arch/x86/kernel/traps_32.c
View File

@ -730,6 +730,8 @@ io_check_error(unsigned char reason, struct pt_regs *regs)
static __kprobes void
unknown_nmi_error(unsigned char reason, struct pt_regs *regs)
{
if (notify_die(DIE_NMIUNKNOWN, "nmi", regs, reason, 2, SIGINT) == NOTIFY_STOP)
return;
#ifdef CONFIG_MCA
/*
* Might actually be able to figure out what the guilty party

9
arch/x86/kernel/traps_64.c
View File

@ -602,8 +602,13 @@ void die(const char * str, struct pt_regs * regs, long err)
void __kprobes die_nmi(char *str, struct pt_regs *regs, int do_panic)
{
unsigned long flags = oops_begin();
unsigned long flags;
if (notify_die(DIE_NMIWATCHDOG, str, regs, 0, 2, SIGINT) ==
NOTIFY_STOP)
return;
flags = oops_begin();
/*
* We are in trouble anyway, lets at least try
* to get a message out.
@ -808,6 +813,8 @@ io_check_error(unsigned char reason, struct pt_regs * regs)
static __kprobes void
unknown_nmi_error(unsigned char reason, struct pt_regs * regs)
{
if (notify_die(DIE_NMIUNKNOWN, "nmi", regs, reason, 2, SIGINT) == NOTIFY_STOP)
return;
printk(KERN_EMERG "Uhhuh. NMI received for unknown reason %02x.\n",
reason);
printk(KERN_EMERG "Do you have a strange power saving mode enabled?\n");

47
drivers/char/tty_io.c
View File

@ -1155,6 +1155,48 @@ static struct tty_driver *get_tty_driver(dev_t device, int *index)
return NULL;
}
#ifdef CONFIG_CONSOLE_POLL
/**
* tty_find_polling_driver - find device of a polled tty
* @name: name string to match
* @line: pointer to resulting tty line nr
*
* This routine returns a tty driver structure, given a name
* and the condition that the tty driver is capable of polled
* operation.
*/
struct tty_driver *tty_find_polling_driver(char *name, int *line)
{
struct tty_driver *p, *res = NULL;
int tty_line = 0;
char *str;
mutex_lock(&tty_mutex);
/* Search through the tty devices to look for a match */
list_for_each_entry(p, &tty_drivers, tty_drivers) {
str = name + strlen(p->name);
tty_line = simple_strtoul(str, &str, 10);
if (*str == ',')
str++;
if (*str == '\0')
str = 0;
if (tty_line >= 0 && tty_line <= p->num && p->poll_init &&
!p->poll_init(p, tty_line, str)) {
res = p;
*line = tty_line;
break;
}
}
mutex_unlock(&tty_mutex);
return res;
}
EXPORT_SYMBOL_GPL(tty_find_polling_driver);
#endif
/**
* tty_check_change - check for POSIX terminal changes
* @tty: tty to check
@ -3850,6 +3892,11 @@ void tty_set_operations(struct tty_driver *driver,
driver->write_proc = op->write_proc;
driver->tiocmget = op->tiocmget;
driver->tiocmset = op->tiocmset;
#ifdef CONFIG_CONSOLE_POLL
driver->poll_init = op->poll_init;
driver->poll_get_char = op->poll_get_char;
driver->poll_put_char = op->poll_put_char;
#endif
}

1
drivers/misc/Makefile
View File

@ -22,3 +22,4 @@ obj-$(CONFIG_FUJITSU_LAPTOP) += fujitsu-laptop.o
obj-$(CONFIG_EEPROM_93CX6) += eeprom_93cx6.o
obj-$(CONFIG_INTEL_MENLOW) += intel_menlow.o
obj-$(CONFIG_ENCLOSURE_SERVICES) += enclosure.o
obj-$(CONFIG_KGDB_TESTS) += kgdbts.o

1090
drivers/misc/kgdbts.c Normal file
View File

File diff suppressed because it is too large Load Diff

58
drivers/serial/8250.c
View File

@ -1740,6 +1740,60 @@ static inline void wait_for_xmitr(struct uart_8250_port *up, int bits)
}
}
#ifdef CONFIG_CONSOLE_POLL
/*
* Console polling routines for writing and reading from the uart while
* in an interrupt or debug context.
*/
static int serial8250_get_poll_char(struct uart_port *port)
{
struct uart_8250_port *up = (struct uart_8250_port *)port;
unsigned char lsr = serial_inp(up, UART_LSR);
while (!(lsr & UART_LSR_DR))
lsr = serial_inp(up, UART_LSR);
return serial_inp(up, UART_RX);
}
static void serial8250_put_poll_char(struct uart_port *port,
unsigned char c)
{
unsigned int ier;
struct uart_8250_port *up = (struct uart_8250_port *)port;
/*
* First save the IER then disable the interrupts
*/
ier = serial_in(up, UART_IER);
if (up->capabilities & UART_CAP_UUE)
serial_out(up, UART_IER, UART_IER_UUE);
else
serial_out(up, UART_IER, 0);
wait_for_xmitr(up, BOTH_EMPTY);
/*
* Send the character out.
* If a LF, also do CR...
*/
serial_out(up, UART_TX, c);
if (c == 10) {
wait_for_xmitr(up, BOTH_EMPTY);
serial_out(up, UART_TX, 13);
}
/*
* Finally, wait for transmitter to become empty
* and restore the IER
*/
wait_for_xmitr(up, BOTH_EMPTY);
serial_out(up, UART_IER, ier);
}
#endif /* CONFIG_CONSOLE_POLL */
static int serial8250_startup(struct uart_port *port)
{
struct uart_8250_port *up = (struct uart_8250_port *)port;
@ -2386,6 +2440,10 @@ static struct uart_ops serial8250_pops = {
.request_port = serial8250_request_port,
.config_port = serial8250_config_port,
.verify_port = serial8250_verify_port,
#ifdef CONFIG_CONSOLE_POLL
.poll_get_char = serial8250_get_poll_char,
.poll_put_char = serial8250_put_poll_char,
#endif
};
static struct uart_8250_port serial8250_ports[UART_NR];

3
drivers/serial/Kconfig
View File

@ -961,6 +961,9 @@ config SERIAL_CORE
config SERIAL_CORE_CONSOLE
bool
config CONSOLE_POLL
bool
config SERIAL_68328
bool "68328 serial support"
depends on M68328 || M68EZ328 || M68VZ328

1
drivers/serial/Makefile
View File

@ -66,4 +66,5 @@ obj-$(CONFIG_SERIAL_UARTLITE) += uartlite.o
obj-$(CONFIG_SERIAL_NETX) += netx-serial.o
obj-$(CONFIG_SERIAL_OF_PLATFORM) += of_serial.o
obj-$(CONFIG_SERIAL_KS8695) += serial_ks8695.o
obj-$(CONFIG_KGDB_SERIAL_CONSOLE) += kgdboc.o
obj-$(CONFIG_SERIAL_QE) += ucc_uart.o

30
drivers/serial/amba-pl011.c
View File

@ -314,6 +314,32 @@ static void pl011_break_ctl(struct uart_port *port, int break_state)
spin_unlock_irqrestore(&uap->port.lock, flags);
}
#ifdef CONFIG_CONSOLE_POLL
static int pl010_get_poll_char(struct uart_port *port)
{
struct uart_amba_port *uap = (struct uart_amba_port *)port;
unsigned int status;
do {
status = readw(uap->port.membase + UART01x_FR);
} while (status & UART01x_FR_RXFE);
return readw(uap->port.membase + UART01x_DR);
}
static void pl010_put_poll_char(struct uart_port *port,
unsigned char ch)
{
struct uart_amba_port *uap = (struct uart_amba_port *)port;
while (readw(uap->port.membase + UART01x_FR) & UART01x_FR_TXFF)
barrier();
writew(ch, uap->port.membase + UART01x_DR);
}
#endif /* CONFIG_CONSOLE_POLL */
static int pl011_startup(struct uart_port *port)
{
struct uart_amba_port *uap = (struct uart_amba_port *)port;
@ -572,6 +598,10 @@ static struct uart_ops amba_pl011_pops = {
.request_port = pl010_request_port,
.config_port = pl010_config_port,
.verify_port = pl010_verify_port,
#ifdef CONFIG_CONSOLE_POLL
.poll_get_char = pl010_get_poll_char,
.poll_put_char = pl010_put_poll_char,
#endif
};
static struct uart_amba_port *amba_ports[UART_NR];

168
drivers/serial/kgdboc.c Normal file
View File

@ -0,0 +1,168 @@
/*
* Based on the same principle as kgdboe using the NETPOLL api, this
* driver uses a console polling api to implement a gdb serial inteface
* which is multiplexed on a console port.
*
* Maintainer: Jason Wessel <jason.wessel@windriver.com>
*
* 2007-2008 (c) Jason Wessel - Wind River Systems, Inc.
*
* This file is licensed under the terms of the GNU General Public
* License version 2. This program is licensed "as is" without any
* warranty of any kind, whether express or implied.
*/
#include <linux/kernel.h>
#include <linux/ctype.h>
#include <linux/kgdb.h>
#include <linux/tty.h>
#define MAX_CONFIG_LEN 40
static struct kgdb_io kgdboc_io_ops;
/* -1 = init not run yet, 0 = unconfigured, 1 = configured. */
static int configured = -1;
static char config[MAX_CONFIG_LEN];
static struct kparam_string kps = {
.string = config,
.maxlen = MAX_CONFIG_LEN,
};
static struct tty_driver *kgdb_tty_driver;
static int kgdb_tty_line;
static int kgdboc_option_setup(char *opt)
{
if (strlen(opt) > MAX_CONFIG_LEN) {
printk(KERN_ERR "kgdboc: config string too long\n");
return -ENOSPC;
}
strcpy(config, opt);
return 0;
}
__setup("kgdboc=", kgdboc_option_setup);
static int configure_kgdboc(void)
{
struct tty_driver *p;
int tty_line = 0;
int err;
err = kgdboc_option_setup(config);
if (err || !strlen(config) || isspace(config[0]))
goto noconfig;
err = -ENODEV;
p = tty_find_polling_driver(config, &tty_line);
if (!p)
goto noconfig;
kgdb_tty_driver = p;
kgdb_tty_line = tty_line;
err = kgdb_register_io_module(&kgdboc_io_ops);
if (err)
goto noconfig;
configured = 1;
return 0;
noconfig:
config[0] = 0;
configured = 0;
return err;
}
static int __init init_kgdboc(void)
{
/* Already configured? */
if (configured == 1)
return 0;
return configure_kgdboc();
}
static void cleanup_kgdboc(void)
{
if (configured == 1)
kgdb_unregister_io_module(&kgdboc_io_ops);
}
static int kgdboc_get_char(void)
{
return kgdb_tty_driver->poll_get_char(kgdb_tty_driver, kgdb_tty_line);
}
static void kgdboc_put_char(u8 chr)
{
kgdb_tty_driver->poll_put_char(kgdb_tty_driver, kgdb_tty_line, chr);
}
static int param_set_kgdboc_var(const char *kmessage, struct kernel_param *kp)
{
int len = strlen(kmessage);
if (len >= MAX_CONFIG_LEN) {
printk(KERN_ERR "kgdboc: config string too long\n");
return -ENOSPC;
}
/* Only copy in the string if the init function has not run yet */
if (configured < 0) {
strcpy(config, kmessage);
return 0;
}
if (kgdb_connected) {
printk(KERN_ERR
"kgdboc: Cannot reconfigure while KGDB is connected.\n");
return -EBUSY;
}
strcpy(config, kmessage);
/* Chop out \n char as a result of echo */
if (config[len - 1] == '\n')
config[len - 1] = '\0';
if (configured == 1)
cleanup_kgdboc();
/* Go and configure with the new params. */
return configure_kgdboc();
}
static void kgdboc_pre_exp_handler(void)
{
/* Increment the module count when the debugger is active */
if (!kgdb_connected)
try_module_get(THIS_MODULE);
}
static void kgdboc_post_exp_handler(void)
{
/* decrement the module count when the debugger detaches */
if (!kgdb_connected)
module_put(THIS_MODULE);
}
static struct kgdb_io kgdboc_io_ops = {
.name = "kgdboc",
.read_char = kgdboc_get_char,
.write_char = kgdboc_put_char,
.pre_exception = kgdboc_pre_exp_handler,
.post_exception = kgdboc_post_exp_handler,
};
module_init(init_kgdboc);
module_exit(cleanup_kgdboc);
module_param_call(kgdboc, param_set_kgdboc_var, param_get_string, &kps, 0644);
MODULE_PARM_DESC(kgdboc, "<serial_device>[,baud]");
MODULE_DESCRIPTION("KGDB Console TTY Driver");
MODULE_LICENSE("GPL");

74
drivers/serial/serial_core.c
View File

@ -1771,7 +1771,7 @@ static int uart_read_proc(char *page, char **start, off_t off,
}
#endif
#ifdef CONFIG_SERIAL_CORE_CONSOLE
#if defined(CONFIG_SERIAL_CORE_CONSOLE) || defined(CONFIG_CONSOLE_POLL)
/*
* uart_console_write - write a console message to a serial port
* @port: the port to write the message
@ -1827,7 +1827,7 @@ uart_get_console(struct uart_port *ports, int nr, struct console *co)
* options. The format of the string is <baud><parity><bits><flow>,
* eg: 115200n8r
*/
void __init
void
uart_parse_options(char *options, int *baud, int *parity, int *bits, int *flow)
{
char *s = options;
@ -1842,6 +1842,7 @@ uart_parse_options(char *options, int *baud, int *parity, int *bits, int *flow)
if (*s)
*flow = *s;
}
EXPORT_SYMBOL_GPL(uart_parse_options);
struct baud_rates {
unsigned int rate;
@ -1872,7 +1873,7 @@ static const struct baud_rates baud_rates[] = {
* @bits: number of data bits
* @flow: flow control character - 'r' (rts)
*/
int __init
int
uart_set_options(struct uart_port *port, struct console *co,
int baud, int parity, int bits, int flow)
{
@ -1924,10 +1925,16 @@ uart_set_options(struct uart_port *port, struct console *co,
port->mctrl |= TIOCM_DTR;
port->ops->set_termios(port, &termios, &dummy);
co->cflag = termios.c_cflag;
/*
* Allow the setting of the UART parameters with a NULL console
* too:
*/
if (co)
co->cflag = termios.c_cflag;
return 0;
}
EXPORT_SYMBOL_GPL(uart_set_options);
#endif /* CONFIG_SERIAL_CORE_CONSOLE */
static void uart_change_pm(struct uart_state *state, int pm_state)
@ -2182,6 +2189,60 @@ uart_configure_port(struct uart_driver *drv, struct uart_state *state,
}
}
#ifdef CONFIG_CONSOLE_POLL
static int uart_poll_init(struct tty_driver *driver, int line, char *options)
{
struct uart_driver *drv = driver->driver_state;
struct uart_state *state = drv->state + line;
struct uart_port *port;
int baud = 9600;
int bits = 8;
int parity = 'n';
int flow = 'n';
if (!state || !state->port)
return -1;
port = state->port;
if (!(port->ops->poll_get_char && port->ops->poll_put_char))
return -1;
if (options) {
uart_parse_options(options, &baud, &parity, &bits, &flow);
return uart_set_options(port, NULL, baud, parity, bits, flow);
}
return 0;
}
static int uart_poll_get_char(struct tty_driver *driver, int line)
{
struct uart_driver *drv = driver->driver_state;
struct uart_state *state = drv->state + line;
struct uart_port *port;
if (!state || !state->port)
return -1;
port = state->port;
return port->ops->poll_get_char(port);
}
static void uart_poll_put_char(struct tty_driver *driver, int line, char ch)
{
struct uart_driver *drv = driver->driver_state;
struct uart_state *state = drv->state + line;
struct uart_port *port;
if (!state || !state->port)
return;
port = state->port;
port->ops->poll_put_char(port, ch);
}
#endif
static const struct tty_operations uart_ops = {
.open = uart_open,
.close = uart_close,
@ -2206,6 +2267,11 @@ static const struct tty_operations uart_ops = {
#endif
.tiocmget = uart_tiocmget,
.tiocmset = uart_tiocmset,
#ifdef CONFIG_CONSOLE_POLL
.poll_init = uart_poll_init,
.poll_get_char = uart_poll_get_char,
.poll_put_char = uart_poll_put_char,
#endif
};
/**

1
include/asm-x86/kdebug.h
View File

@ -20,6 +20,7 @@ enum die_val {
DIE_CALL,
DIE_NMI_IPI,
DIE_PAGE_FAULT,
DIE_NMIUNKNOWN,
};
extern void printk_address(unsigned long address, int reliable);

81
include/asm-x86/kgdb.h Normal file
View File

@ -0,0 +1,81 @@
#ifndef _ASM_KGDB_H_
#define _ASM_KGDB_H_
/*
* Copyright (C) 2001-2004 Amit S. Kale
* Copyright (C) 2008 Wind River Systems, Inc.
*/
/*
* BUFMAX defines the maximum number of characters in inbound/outbound
* buffers at least NUMREGBYTES*2 are needed for register packets
* Longer buffer is needed to list all threads
*/
#define BUFMAX 1024
/*
* Note that this register image is in a different order than
* the register image that Linux produces at interrupt time.
*
* Linux's register image is defined by struct pt_regs in ptrace.h.
* Just why GDB uses a different order is a historical mystery.
*/
#ifdef CONFIG_X86_32
enum regnames {
GDB_AX, /* 0 */
GDB_CX, /* 1 */
GDB_DX, /* 2 */
GDB_BX, /* 3 */
GDB_SP, /* 4 */
GDB_BP, /* 5 */
GDB_SI, /* 6 */
GDB_DI, /* 7 */
GDB_PC, /* 8 also known as eip */
GDB_PS, /* 9 also known as eflags */
GDB_CS, /* 10 */
GDB_SS, /* 11 */
GDB_DS, /* 12 */
GDB_ES, /* 13 */
GDB_FS, /* 14 */
GDB_GS, /* 15 */
};
#else /* ! CONFIG_X86_32 */
enum regnames {
GDB_AX, /* 0 */
GDB_DX, /* 1 */
GDB_CX, /* 2 */
GDB_BX, /* 3 */
GDB_SI, /* 4 */
GDB_DI, /* 5 */
GDB_BP, /* 6 */
GDB_SP, /* 7 */
GDB_R8, /* 8 */
GDB_R9, /* 9 */
GDB_R10, /* 10 */
GDB_R11, /* 11 */
GDB_R12, /* 12 */
GDB_R13, /* 13 */
GDB_R14, /* 14 */
GDB_R15, /* 15 */
GDB_PC, /* 16 */
GDB_PS, /* 17 */
};
#endif /* CONFIG_X86_32 */
/*
* Number of bytes of registers:
*/
#ifdef CONFIG_X86_32
# define NUMREGBYTES 64
#else
# define NUMREGBYTES ((GDB_PS+1)*8)
#endif
static inline void arch_kgdb_breakpoint(void)
{
asm(" int $3");
}
#define BREAK_INSTR_SIZE 1
#define CACHE_FLUSH_IS_SAFE 1
#endif /* _ASM_KGDB_H_ */

1
include/linux/clocksource.h
View File

@ -216,6 +216,7 @@ static inline void clocksource_calculate_interval(struct clocksource *c,
/* used to install a new clocksource */
extern int clocksource_register(struct clocksource*);
extern void clocksource_unregister(struct clocksource*);
extern void clocksource_touch_watchdog(void);
extern struct clocksource* clocksource_get_next(void);
extern void clocksource_change_rating(struct clocksource *cs, int rating);
extern void clocksource_resume(void);

281
include/linux/kgdb.h Normal file
View File

@ -0,0 +1,281 @@
/*
* This provides the callbacks and functions that KGDB needs to share between
* the core, I/O and arch-specific portions.
*
* Author: Amit Kale <amitkale@linsyssoft.com> and
* Tom Rini <trini@kernel.crashing.org>
*
* 2001-2004 (c) Amit S. Kale and 2003-2005 (c) MontaVista Software, Inc.
* This file is licensed under the terms of the GNU General Public License
* version 2. This program is licensed "as is" without any warranty of any
* kind, whether express or implied.
*/
#ifndef _KGDB_H_
#define _KGDB_H_
#include <linux/serial_8250.h>
#include <linux/linkage.h>
#include <linux/init.h>
#include <asm/atomic.h>
#include <asm/kgdb.h>
struct pt_regs;
/**
* kgdb_skipexception - (optional) exit kgdb_handle_exception early
* @exception: Exception vector number
* @regs: Current &struct pt_regs.
*
* On some architectures it is required to skip a breakpoint
* exception when it occurs after a breakpoint has been removed.
* This can be implemented in the architecture specific portion of
* for kgdb.
*/
extern int kgdb_skipexception(int exception, struct pt_regs *regs);
/**
* kgdb_post_primary_code - (optional) Save error vector/code numbers.
* @regs: Original pt_regs.
* @e_vector: Original error vector.
* @err_code: Original error code.
*
* This is usually needed on architectures which support SMP and
* KGDB. This function is called after all the secondary cpus have
* been put to a know spin state and the primary CPU has control over
* KGDB.
*/
extern void kgdb_post_primary_code(struct pt_regs *regs, int e_vector,
int err_code);
/**
* kgdb_disable_hw_debug - (optional) Disable hardware debugging hook
* @regs: Current &struct pt_regs.
*
* This function will be called if the particular architecture must
* disable hardware debugging while it is processing gdb packets or
* handling exception.
*/
extern void kgdb_disable_hw_debug(struct pt_regs *regs);
struct tasklet_struct;
struct task_struct;
struct uart_port;
/**
* kgdb_breakpoint - compiled in breakpoint
*
* This will be impelmented a static inline per architecture. This
* function is called by the kgdb core to execute an architecture
* specific trap to cause kgdb to enter the exception processing.
*
*/
void kgdb_breakpoint(void);
extern int kgdb_connected;
extern atomic_t kgdb_setting_breakpoint;
extern atomic_t kgdb_cpu_doing_single_step;
extern struct task_struct *kgdb_usethread;
extern struct task_struct *kgdb_contthread;
enum kgdb_bptype {
BP_BREAKPOINT = 0,
BP_HARDWARE_BREAKPOINT,
BP_WRITE_WATCHPOINT,
BP_READ_WATCHPOINT,
BP_ACCESS_WATCHPOINT
};
enum kgdb_bpstate {
BP_UNDEFINED = 0,
BP_REMOVED,
BP_SET,
BP_ACTIVE
};
struct kgdb_bkpt {
unsigned long bpt_addr;
unsigned char saved_instr[BREAK_INSTR_SIZE];
enum kgdb_bptype type;
enum kgdb_bpstate state;
};
#ifndef KGDB_MAX_BREAKPOINTS
# define KGDB_MAX_BREAKPOINTS 1000
#endif
#define KGDB_HW_BREAKPOINT 1
/*
* Functions each KGDB-supporting architecture must provide:
*/
/**
* kgdb_arch_init - Perform any architecture specific initalization.
*
* This function will handle the initalization of any architecture
* specific callbacks.
*/
extern int kgdb_arch_init(void);
/**
* kgdb_arch_exit - Perform any architecture specific uninitalization.
*
* This function will handle the uninitalization of any architecture
* specific callbacks, for dynamic registration and unregistration.
*/
extern void kgdb_arch_exit(void);
/**
* pt_regs_to_gdb_regs - Convert ptrace regs to GDB regs
* @gdb_regs: A pointer to hold the registers in the order GDB wants.
* @regs: The &struct pt_regs of the current process.
*
* Convert the pt_regs in @regs into the format for registers that
* GDB expects, stored in @gdb_regs.
*/
extern void pt_regs_to_gdb_regs(unsigned long *gdb_regs, struct pt_regs *regs);
/**
* sleeping_thread_to_gdb_regs - Convert ptrace regs to GDB regs
* @gdb_regs: A pointer to hold the registers in the order GDB wants.
* @p: The &struct task_struct of the desired process.
*
* Convert the register values of the sleeping process in @p to
* the format that GDB expects.
* This function is called when kgdb does not have access to the
* &struct pt_regs and therefore it should fill the gdb registers
* @gdb_regs with what has been saved in &struct thread_struct
* thread field during switch_to.
*/
extern void
sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, struct task_struct *p);
/**
* gdb_regs_to_pt_regs - Convert GDB regs to ptrace regs.
* @gdb_regs: A pointer to hold the registers we've received from GDB.
* @regs: A pointer to a &struct pt_regs to hold these values in.
*
* Convert the GDB regs in @gdb_regs into the pt_regs, and store them
* in @regs.
*/
extern void gdb_regs_to_pt_regs(unsigned long *gdb_regs, struct pt_regs *regs);
/**
* kgdb_arch_handle_exception - Handle architecture specific GDB packets.
* @vector: The error vector of the exception that happened.
* @signo: The signal number of the exception that happened.
* @err_code: The error code of the exception that happened.
* @remcom_in_buffer: The buffer of the packet we have read.
* @remcom_out_buffer: The buffer of %BUFMAX bytes to write a packet into.
* @regs: The &struct pt_regs of the current process.
*
* This function MUST handle the 'c' and 's' command packets,
* as well packets to set / remove a hardware breakpoint, if used.
* If there are additional packets which the hardware needs to handle,
* they are handled here. The code should return -1 if it wants to
* process more packets, and a %0 or %1 if it wants to exit from the
* kgdb callback.
*/
extern int
kgdb_arch_handle_exception(int vector, int signo, int err_code,
char *remcom_in_buffer,
char *remcom_out_buffer,
struct pt_regs *regs);
/**
* kgdb_roundup_cpus - Get other CPUs into a holding pattern
* @flags: Current IRQ state
*
* On SMP systems, we need to get the attention of the other CPUs
* and get them be in a known state. This should do what is needed
* to get the other CPUs to call kgdb_wait(). Note that on some arches,
* the NMI approach is not used for rounding up all the CPUs. For example,
* in case of MIPS, smp_call_function() is used to roundup CPUs. In
* this case, we have to make sure that interrupts are enabled before
* calling smp_call_function(). The argument to this function is
* the flags that will be used when restoring the interrupts. There is
* local_irq_save() call before kgdb_roundup_cpus().
*
* On non-SMP systems, this is not called.
*/
extern void kgdb_roundup_cpus(unsigned long flags);
/* Optional functions. */
extern int kgdb_validate_break_address(unsigned long addr);
extern int kgdb_arch_set_breakpoint(unsigned long addr, char *saved_instr);
extern int kgdb_arch_remove_breakpoint(unsigned long addr, char *bundle);
/**
* struct kgdb_arch - Describe architecture specific values.
* @gdb_bpt_instr: The instruction to trigger a breakpoint.
* @flags: Flags for the breakpoint, currently just %KGDB_HW_BREAKPOINT.
* @set_breakpoint: Allow an architecture to specify how to set a software
* breakpoint.
* @remove_breakpoint: Allow an architecture to specify how to remove a
* software breakpoint.
* @set_hw_breakpoint: Allow an architecture to specify how to set a hardware
* breakpoint.
* @remove_hw_breakpoint: Allow an architecture to specify how to remove a
* hardware breakpoint.
* @remove_all_hw_break: Allow an architecture to specify how to remove all
* hardware breakpoints.
* @correct_hw_break: Allow an architecture to specify how to correct the
* hardware debug registers.
*/
struct kgdb_arch {
unsigned char gdb_bpt_instr[BREAK_INSTR_SIZE];
unsigned long flags;
int (*set_breakpoint)(unsigned long, char *);
int (*remove_breakpoint)(unsigned long, char *);
int (*set_hw_breakpoint)(unsigned long, int, enum kgdb_bptype);
int (*remove_hw_breakpoint)(unsigned long, int, enum kgdb_bptype);
void (*remove_all_hw_break)(void);
void (*correct_hw_break)(void);
};
/**
* struct kgdb_io - Describe the interface for an I/O driver to talk with KGDB.
* @name: Name of the I/O driver.
* @read_char: Pointer to a function that will return one char.
* @write_char: Pointer to a function that will write one char.
* @flush: Pointer to a function that will flush any pending writes.
* @init: Pointer to a function that will initialize the device.
* @pre_exception: Pointer to a function that will do any prep work for
* the I/O driver.
* @post_exception: Pointer to a function that will do any cleanup work
* for the I/O driver.
*/
struct kgdb_io {
const char *name;
int (*read_char) (void);
void (*write_char) (u8);
void (*flush) (void);
int (*init) (void);
void (*pre_exception) (void);
void (*post_exception) (void);
};
extern struct kgdb_arch arch_kgdb_ops;
extern int kgdb_register_io_module(struct kgdb_io *local_kgdb_io_ops);
extern void kgdb_unregister_io_module(struct kgdb_io *local_kgdb_io_ops);
extern int kgdb_hex2long(char **ptr, long *long_val);
extern int kgdb_mem2hex(char *mem, char *buf, int count);
extern int kgdb_hex2mem(char *buf, char *mem, int count);
extern int kgdb_isremovedbreak(unsigned long addr);
extern int
kgdb_handle_exception(int ex_vector, int signo, int err_code,
struct pt_regs *regs);
extern int kgdb_nmicallback(int cpu, void *regs);
extern int kgdb_single_step;
extern atomic_t kgdb_active;
#endif /* _KGDB_H_ */

4
include/linux/serial_core.h
View File

@ -213,6 +213,10 @@ struct uart_ops {
void (*config_port)(struct uart_port *, int);
int (*verify_port)(struct uart_port *, struct serial_struct *);
int (*ioctl)(struct uart_port *, unsigned int, unsigned long);
#ifdef CONFIG_CONSOLE_POLL
void (*poll_put_char)(struct uart_port *, unsigned char);
int (*poll_get_char)(struct uart_port *);
#endif
};
#define UART_CONFIG_TYPE (1 << 0)

12
include/linux/tty_driver.h
View File

@ -125,6 +125,7 @@
#include <linux/cdev.h>
struct tty_struct;
struct tty_driver;
struct tty_operations {
int (*open)(struct tty_struct * tty, struct file * filp);
@ -157,6 +158,11 @@ struct tty_operations {
int (*tiocmget)(struct tty_struct *tty, struct file *file);
int (*tiocmset)(struct tty_struct *tty, struct file *file,
unsigned int set, unsigned int clear);
#ifdef CONFIG_CONSOLE_POLL
int (*poll_init)(struct tty_driver *driver, int line, char *options);
int (*poll_get_char)(struct tty_driver *driver, int line);
void (*poll_put_char)(struct tty_driver *driver, int line, char ch);
#endif
};
struct tty_driver {
@ -220,6 +226,11 @@ struct tty_driver {
int (*tiocmget)(struct tty_struct *tty, struct file *file);
int (*tiocmset)(struct tty_struct *tty, struct file *file,
unsigned int set, unsigned int clear);
#ifdef CONFIG_CONSOLE_POLL
int (*poll_init)(struct tty_driver *driver, int line, char *options);
int (*poll_get_char)(struct tty_driver *driver, int line);
void (*poll_put_char)(struct tty_driver *driver, int line, char ch);
#endif
struct list_head tty_drivers;
};
@ -230,6 +241,7 @@ struct tty_driver *alloc_tty_driver(int lines);
void put_tty_driver(struct tty_driver *driver);
void tty_set_operations(struct tty_driver *driver,
const struct tty_operations *op);
extern struct tty_driver *tty_find_polling_driver(char *name, int *line);
/* tty driver magic number */
#define TTY_DRIVER_MAGIC 0x5402

22
include/linux/uaccess.h
View File

@ -84,4 +84,26 @@ static inline unsigned long __copy_from_user_nocache(void *to,
ret; \
})
/*
* probe_kernel_read(): safely attempt to read from a location
* @dst: pointer to the buffer that shall take the data
* @src: address to read from
* @size: size of the data chunk
*
* Safely read from address @src to the buffer at @dst. If a kernel fault
* happens, handle that and return -EFAULT.
*/
extern long probe_kernel_read(void *dst, void *src, size_t size);
/*
* probe_kernel_write(): safely attempt to write to a location
* @dst: address to write to
* @src: pointer to the data that shall be written
* @size: size of the data chunk
*
* Safely write to address @dst from the buffer at @src. If a kernel fault
* happens, handle that and return -EFAULT.
*/
extern long probe_kernel_write(void *dst, void *src, size_t size);
#endif /* __LINUX_UACCESS_H__ */

1
kernel/Makefile
View File

@ -53,6 +53,7 @@ obj-$(CONFIG_AUDIT) += audit.o auditfilter.o
obj-$(CONFIG_AUDITSYSCALL) += auditsc.o
obj-$(CONFIG_AUDIT_TREE) += audit_tree.o
obj-$(CONFIG_KPROBES) += kprobes.o
obj-$(CONFIG_KGDB) += kgdb.o
obj-$(CONFIG_DETECT_SOFTLOCKUP) += softlockup.o
obj-$(CONFIG_GENERIC_HARDIRQS) += irq/
obj-$(CONFIG_SECCOMP) += seccomp.o

1700
kernel/kgdb.c Normal file
View File

File diff suppressed because it is too large Load Diff

12
kernel/time/clocksource.c
View File

@ -221,6 +221,18 @@ void clocksource_resume(void)
spin_unlock_irqrestore(&clocksource_lock, flags);
}
/**
* clocksource_touch_watchdog - Update watchdog
*
* Update the watchdog after exception contexts such as kgdb so as not
* to incorrectly trip the watchdog.
*
*/
void clocksource_touch_watchdog(void)
{
clocksource_resume_watchdog();
}
/**
* clocksource_get_next - Returns the selected clocksource
*

2
lib/Kconfig.debug
View File

@ -612,3 +612,5 @@ config PROVIDE_OHCI1394_DMA_INIT
See Documentation/debugging-via-ohci1394.txt for more information.
source "samples/Kconfig"
source "lib/Kconfig.kgdb"

58
lib/Kconfig.kgdb Normal file
View File

@ -0,0 +1,58 @@
menuconfig KGDB
bool "KGDB: kernel debugging with remote gdb"
select FRAME_POINTER
depends on HAVE_ARCH_KGDB
depends on DEBUG_KERNEL && EXPERIMENTAL
help
If you say Y here, it will be possible to remotely debug the
kernel using gdb. Documentation of kernel debugger is available
at http://kgdb.sourceforge.net as well as in DocBook form
in Documentation/DocBook/. If unsure, say N.
config HAVE_ARCH_KGDB_SHADOW_INFO
bool
config HAVE_ARCH_KGDB
bool
config KGDB_SERIAL_CONSOLE
tristate "KGDB: use kgdb over the serial console"
depends on KGDB
select CONSOLE_POLL
select MAGIC_SYSRQ
default y
help
Share a serial console with kgdb. Sysrq-g must be used
to break in initially.
config KGDB_TESTS
bool "KGDB: internal test suite"
depends on KGDB
default n
help
This is a kgdb I/O module specifically designed to test
kgdb's internal functions. This kgdb I/O module is
intended to for the development of new kgdb stubs
as well as regression testing the kgdb internals.
See the drivers/misc/kgdbts.c for the details about
the tests. The most basic of this I/O module is to boot
a kernel boot arguments "kgdbwait kgdbts=V1F100"
config KGDB_TESTS_ON_BOOT
bool "KGDB: Run tests on boot"
depends on KGDB_TESTS
default n
help
Run the kgdb tests on boot up automatically without the need
to pass in a kernel parameter
config KGDB_TESTS_BOOT_STRING
string "KGDB: which internal kgdb tests to run"
depends on KGDB_TESTS_ON_BOOT
default "V1F100"
help
This is the command string to send the kgdb test suite on
boot. See the drivers/misc/kgdbts.c for detailed
information about other strings you could use beyond the
default of V1F100.

2
mm/Makefile
View File

@ -8,7 +8,7 @@ mmu-$(CONFIG_MMU) := fremap.o highmem.o madvise.o memory.o mincore.o \
vmalloc.o
obj-y := bootmem.o filemap.o mempool.o oom_kill.o fadvise.o \
page_alloc.o page-writeback.o pdflush.o \
maccess.o page_alloc.o page-writeback.o pdflush.o \
readahead.o swap.o truncate.o vmscan.o \
prio_tree.o util.o mmzone.o vmstat.o backing-dev.o \
page_isolation.o $(mmu-y)

55
mm/maccess.c Normal file
View File

@ -0,0 +1,55 @@
/*
* Access kernel memory without faulting.
*/
#include <linux/uaccess.h>
#include <linux/module.h>
#include <linux/mm.h>
/**
* probe_kernel_read(): safely attempt to read from a location
* @dst: pointer to the buffer that shall take the data
* @src: address to read from
* @size: size of the data chunk
*
* Safely read from address @src to the buffer at @dst. If a kernel fault
* happens, handle that and return -EFAULT.
*/
long probe_kernel_read(void *dst, void *src, size_t size)
{
long ret;
mm_segment_t old_fs = get_fs();
set_fs(KERNEL_DS);
pagefault_disable();
ret = __copy_from_user_inatomic(dst,
(__force const void __user *)src, size);
pagefault_enable();
set_fs(old_fs);
return ret ? -EFAULT : 0;
}
EXPORT_SYMBOL_GPL(probe_kernel_read);
/**
* probe_kernel_write(): safely attempt to write to a location
* @dst: address to write to
* @src: pointer to the data that shall be written
* @size: size of the data chunk
*
* Safely write to address @dst from the buffer at @src. If a kernel fault
* happens, handle that and return -EFAULT.
*/
long probe_kernel_write(void *dst, void *src, size_t size)
{
long ret;
mm_segment_t old_fs = get_fs();
set_fs(KERNEL_DS);
pagefault_disable();
ret = __copy_to_user_inatomic((__force void __user *)dst, src, size);
pagefault_enable();
set_fs(old_fs);
return ret ? -EFAULT : 0;
}
EXPORT_SYMBOL_GPL(probe_kernel_write);