Merge branch 'upstream'

#

# Top-level generic files

#

tags

vmlinux*

System.map

Module.symvers

S: USA

N: Philip Gladstone

E: philip@raptor.com

E: philip@gladstonefamily.net

D: Kernel / timekeeping stuff

S: Carlisle, MA 01741

S: USA

N: Jan-Benedict Glaw

E: jbglaw@lug-owl.de

S: Ecole Nationale Superieure des Telecommunications, Paris

N: Jamie Lokier

E: jamie@imbolc.ucc.ie

E: jamie@shareable.org

W: http://www.shareable.org/

D: Reboot-through-BIOS for broken 486 motherboards

D: Some parport fixes

S: 11 Goodson Walk

S: Marston

D: Parport fixes, futex improvements

D: First instruction of x86 sysenter path :)

S: 51 Sunningwell Road

S: Oxford

S: OX3 0HX

S: OX1 4SZ

S: United Kingdom

N: Mark Lord

D: Miscellaneous kernel fixes

N: Alessandro Zummo

E: azummo@ita.flashnet.it

W: http://freepage.logicom.it/azummo/

E: a.zummo@towertech.it

D: CMI8330 support is sb_card.c

D: ISAPnP fixes in sb_card.c

D: ZyXEL omni.net lcd plus driver

D: RTC subsystem

S: Italy

N: Marc Zyngier

Table of contents

=================

Last updated: 20 December 2005

Contents

========

- Introduction

- Devices not appearing

- Finding patch that caused a bug

-- Finding using git-bisect

-- Finding it the old way

- Fixing the bug

Introduction

============

Always try the latest kernel from kernel.org and build from source. If you are

not confident in doing that please report the bug to your distribution vendor

instead of to a kernel developer.

Finding bugs is not always easy. Have a go though. If you can't find it don't

give up. Report as much as you have found to the relevant maintainer. See

MAINTAINERS for who that is for the subsystem you have worked on.

Before you submit a bug report read REPORTING-BUGS.

Devices not appearing

=====================

Often this is caused by udev. Check that first before blaming it on the

kernel.

Finding patch that caused a bug

===============================

Finding using git-bisect

------------------------

Using the provided tools with git makes finding bugs easy provided the bug is

reproducible.

Steps to do it:

- start using git for the kernel source

- read the man page for git-bisect

- have fun

Finding it the old way

----------------------

[Sat Mar  2 10:32:33 PST 1996 KERNEL_BUG-HOWTO lm@sgi.com (Larry McVoy)]

This is how to track down a bug if you know nothing about kernel hacking.  

because Linux snapshots will let you do this - something that you can't

do with vendor supplied releases.

Fixing the bug

==============

Nobody is going to tell you how to fix bugs. Seriously. You need to work it

out. But below are some hints on how to use the tools.

To debug a kernel, use objdump and look for the hex offset from the crash

output to find the valid line of code/assembler. Without debug symbols, you

will see the assembler code for the routine shown, but if your kernel has

debug symbols the C code will also be available. (Debug symbols can be enabled

in the kernel hacking menu of the menu configuration.) For example:

    objdump -r -S -l --disassemble net/dccp/ipv4.o

NB.: you need to be at the top level of the kernel tree for this to pick up

your C files.

If you don't have access to the code you can also debug on some crash dumps

e.g. crash dump output as shown by Dave Miller.

>    EIP is at ip_queue_xmit+0x14/0x4c0

>     ...

>    Code: 44 24 04 e8 6f 05 00 00 e9 e8 fe ff ff 8d 76 00 8d bc 27 00 00

>    00 00 55 57  56 53 81 ec bc 00 00 00 8b ac 24 d0 00 00 00 8b 5d 08

>    <8b> 83 3c 01 00 00 89 44  24 14 8b 45 28 85 c0 89 44 24 18 0f 85

>

>    Put the bytes into a "foo.s" file like this:

>

>           .text

>           .globl foo

>    foo:

>           .byte  .... /* bytes from Code: part of OOPS dump */

>

>    Compile it with "gcc -c -o foo.o foo.s" then look at the output of

>    "objdump --disassemble foo.o".

>

>    Output:

>

>    ip_queue_xmit:

>        push       %ebp

>        push       %edi

>        push       %esi

>        push       %ebx

>        sub        $0xbc, %esp

>        mov        0xd0(%esp), %ebp        ! %ebp = arg0 (skb)

>        mov        0x8(%ebp), %ebx         ! %ebx = skb->sk

>        mov        0x13c(%ebx), %eax       ! %eax = inet_sk(sk)->opt

Another very useful option of the Kernel Hacking section in menuconfig is

Debug memory allocations. This will help you see whether data has been

initialised and not set before use etc. To see the values that get assigned

with this look at mm/slab.c and search for POISON_INUSE. When using this an

Oops will often show the poisoned data instead of zero which is the default.

Once you have worked out a fix please submit it upstream. After all open

source is about sharing what you do and don't you want to be recognised for

your genius?

Please do read Documentation/SubmittingPatches though to help your code get

accepted.

		       "mydev: 24-bit DMA addressing not available.\n");

		goto ignore_this_device;

	}

[Better use DMA_24BIT_MASK instead of 0x00ffffff.

See linux/include/dma-mapping.h for reference.]

When pci_set_dma_mask() is successful, and returns zero, the PCI layer

saves away this mask you have provided.  The PCI layer will use this

###

# The targets that may be used.

.PHONY:	xmldocs sgmldocs psdocs pdfdocs htmldocs mandocs installmandocs

PHONY += xmldocs sgmldocs psdocs pdfdocs htmldocs mandocs installmandocs

BOOKS := $(addprefix $(obj)/,$(DOCBOOKS))

xmldocs: $(BOOKS)

#man put files in man subdir - traverse down

subdir- := man/

# Declare the contents of the .PHONY variable as phony.  We keep that

# information in a variable se we can use it in if_changed and friends.

.PHONY: $(PHONY)