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Shawn Guo 2af502ca64 mmc: sdhci: request irq after sdhci_init() is called
Generally request_irq() should be called after hardware has been
initialized into a sane state.  However, sdhci driver currently calls
request_irq() before sdhci_init().  At least, the following kernel panic
seen on i.MX6 is caused by that.  The sdhci controller on i.MX6 may have
noisy glitch on DAT1 line, which will trigger SDIO interrupt handling
once request_irq() is called.  But at this point, the SDIO interrupt
handler host->sdio_irq_thread has not been registered yet.  Thus, we
see the NULL pointer access with wake_up_process(host->sdio_irq_thread)
in mmc_signal_sdio_irq().

Fix the panic by simply reverse the calling sequence between
request_irq() and sdhci_init().

sdhci-pltfm: SDHCI platform and OF driver helper
mmc0: no vqmmc regulator found
mmc0: no vmmc regulator found
Unable to handle kernel NULL pointer dereference at virtual address 00000000
pgd = 80004000
[00000000] *pgd=00000000
Internal error: Oops: 5 [#1] SMP ARM
Modules linked in:
CPU: 0 PID: 1 Comm: swapper/0 Not tainted 3.10.0+ #3
task: 9f860000 ti: 9f862000 task.ti: 9f862000
PC is at wake_up_process+0xc/0x44
LR is at sdhci_irq+0x378/0x93c
pc : [<8004f768>]    lr : [<803fb698>]    psr: 40000193
sp : 9f863ba0  ip : 9f863bb8  fp : 9f863bb4
r10: 9f807900  r9 : 80761fbc  r8 : 00000000
r7 : 00000000  r6 : 00000000  r5 : 00000001  r4 : 9fa68000
r3 : 00000001  r2 : 00000002  r1 : 20000193  r0 : 00000000
Flags: nZcv  IRQs off  FIQs on  Mode SVC_32  ISA ARM  Segment kernel
Control: 10c53c7d  Table: 8000404a  DAC: 00000017
Process swapper/0 (pid: 1, stack limit = 0x9f862238)
Stack: (0x9f863ba0 to 0x9f864000)
3ba0: 00000001 9fa68000 9f863c04 9f863bb8 803fb698 8004f768 8011af00 80265aac
3bc0: 00000000 000003d9 00000000 9fa51880 00000001 00000000 9f863c14 9fa53640
3be0: 00000001 00000000 00000000 00000036 80761fbc 9f807900 9f863c3c 9f863c08
3c00: 80075154 803fb32c 802c2b38 802c63d8 802c63cc 9f807900 00000001 9f862000
3c20: 00000036 00000000 9f807930 60000113 9f863c54 9f863c40 800752ec 8007510c
3c40: 9f807900 00000001 9f863c6c 9f863c58 80078324 800752a8 00000036 8071fd64
3c60: 9f863c84 9f863c70 80074ac0 80078294 00000140 8072ab78 9f863cac 9f863c88
3c80: 8000ee34 80074aa4 00000000 a080e10c 8072acbc 9f863cd0 a080e100 00000036
3ca0: 9f863ccc 9f863cb0 80008600 8000edec 805386a8 60000113 ffffffff 9f863d04
3cc0: 9f863d24 9f863cd0 8000e0c0 800085dc 9f807950 60000113 00000007 00000000
3ce0: 9f807900 9fa53640 9f807950 9fa68240 00000036 9f807930 60000113 9f863d24
3d00: 9f863d28 9f863d18 80076834 805386a8 60000113 ffffffff 9f863d64 9f863d28
3d20: 80076834 80538688 00000000 800bfe4c 00002fac 00000001 9f863d54 9fa53640
3d40: 9f807900 803fb320 9fa68240 00000080 00000000 00000036 9f863d94 9f863d68
3d60: 80076b38 80076674 00000080 9fa68240 9fa68000 04000000 9fa6836c 9fa68380
3d80: 806d620c 80700350 9f863dc4 9f863d98 803fce8c 80076a88 9fa532c0 9fa68240
3da0: 9fa51490 9fa51490 9fa68240 00000000 9f8ae600 9f81d080 9f863df4 9f863dc8
3dc0: 803fea0c 803fc808 9f863de4 9f863dd8 80125850 807b1ed8 807576b8 9f8ae610
3de0: 00000000 807576b8 9f863e04 9f863df8 802ee0d4 803fe798 9f863e2c 9f863e08
3e00: 802ecd1c 802ee0c0 00000000 9f8ae610 807576b8 9f8ae644 00000000 000000a9
3e20: 9f863e4c 9f863e30 802ecec0 802ecc30 9f83355c 807576b8 802ece2c 00000000
3e40: 9f863e74 9f863e50 802eb3d8 802ece38 9f83355c 9f8ac3b4 9f833570 807576b8
3e60: 80746e70 9fa51400 9f863e84 9f863e78 802ec838 802eb388 9f863eb4 9f863e88
3e80: 802ec3d0 802ec824 80692748 807620c0 9f863eb4 807576b8 00000006 807620c0
3ea0: 00000000 000000a9 9f863edc 9f863eb8 802ed3e8 802ec2fc 9f862000 00000006
3ec0: 807620c0 00000000 000000a9 80700350 9f863eec 9f863ee0 802ee2f8 802ed374
3ee0: 9f863efc 9f863ef0 80700364 802ee2b8 9f863f54 9f863f00 8000870c 8070035c
3f00: 9f863f54 9f863f10 9f862000 00000000 00000000 00000006 00000006 806d3aa4
3f20: 00000000 80688b18 9f863f54 80713560 00000006 80713540 807620c0 000000a9
3f40: 806d620c 8071ec24 9f863f94 9f863f58 806d6994 800086dc 00000006 00000006
3f60: 806d620c f6bfffff fb7f5df7 00000000 8052da28 00000000 00000000 00000000
3f80: 00000000 00000000 9f863fac 9f863f98 8052da38 806d689c ffffffff 00000000
3fa0: 00000000 9f863fb0 8000e5d8 8052da34 00000000 00000000 00000000 00000000
3fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
3fe0: 00000000 00000000 00000000 00000000 00000013 00000000 d9cdf5ff 1fff5ffe
Backtrace:
[<8004f75c>] (wake_up_process+0x0/0x44) from [<803fb698>] (sdhci_irq+0x378/0x93c)
 r4:9fa68000 r3:00000001
[<803fb320>] (sdhci_irq+0x0/0x93c) from [<80075154>] (handle_irq_event_percpu+0x54/0x19c)
[<80075100>] (handle_irq_event_percpu+0x0/0x19c) from [<800752ec>] (handle_irq_event+0x50/0x70)
[<8007529c>] (handle_irq_event+0x0/0x70) from [<80078324>] (handle_fasteoi_irq+0x9c/0x170)
 r5:00000001 r4:9f807900
[<80078288>] (handle_fasteoi_irq+0x0/0x170) from [<80074ac0>] (generic_handle_irq+0x28/0x38)
 r5:8071fd64 r4:00000036
[<80074a98>] (generic_handle_irq+0x0/0x38) from [<8000ee34>] (handle_IRQ+0x54/0xb4)
 r4:8072ab78 r3:00000140
[<8000ede0>] (handle_IRQ+0x0/0xb4) from [<80008600>] (gic_handle_irq+0x30/0x64)
 r8:00000036 r7:a080e100 r6:9f863cd0 r5:8072acbc r4:a080e10c
r3:00000000
[<800085d0>] (gic_handle_irq+0x0/0x64) from [<8000e0c0>] (__irq_svc+0x40/0x54)
Exception stack(0x9f863cd0 to 0x9f863d18)
3cc0:                                     9f807950 60000113 00000007 00000000
3ce0: 9f807900 9fa53640 9f807950 9fa68240 00000036 9f807930 60000113 9f863d24
3d00: 9f863d28 9f863d18 80076834 805386a8 60000113 ffffffff
 r7:9f863d04 r6:ffffffff r5:60000113 r4:805386a8
[<8053867c>] (_raw_spin_unlock_irqrestore+0x0/0x30) from [<80076834>] (__setup_irq+0x1cc/0x414)
[<80076668>] (__setup_irq+0x0/0x414) from [<80076b38>] (request_threaded_irq+0xbc/0x140)
[<80076a7c>] (request_threaded_irq+0x0/0x140) from [<803fce8c>] (sdhci_add_host+0x690/0xb88)
[<803fc7fc>] (sdhci_add_host+0x0/0xb88) from [<803fea0c>] (sdhci_esdhc_imx_probe+0x280/0x4d4)
 r8:9f81d080 r7:9f8ae600 r6:00000000 r5:9fa68240 r4:9fa51490
[<803fe78c>] (sdhci_esdhc_imx_probe+0x0/0x4d4) from [<802ee0d4>] (platform_drv_probe+0x20/0x24)
 r8:807576b8 r7:00000000 r6:9f8ae610 r5:807576b8 r4:807b1ed8
[<802ee0b4>] (platform_drv_probe+0x0/0x24) from [<802ecd1c>] (driver_probe_device+0xf8/0x208)
[<802ecc24>] (driver_probe_device+0x0/0x208) from [<802ecec0>] (__driver_attach+0x94/0x98)
 r8:000000a9 r7:00000000 r6:9f8ae644 r5:807576b8 r4:9f8ae610
r3:00000000
[<802ece2c>] (__driver_attach+0x0/0x98) from [<802eb3d8>] (bus_for_each_dev+0x5c/0x90)
 r6:00000000 r5:802ece2c r4:807576b8 r3:9f83355c
[<802eb37c>] (bus_for_each_dev+0x0/0x90) from [<802ec838>] (driver_attach+0x20/0x28)
 r6:9fa51400 r5:80746e70 r4:807576b8
[<802ec818>] (driver_attach+0x0/0x28) from [<802ec3d0>] (bus_add_driver+0xe0/0x234)
[<802ec2f0>] (bus_add_driver+0x0/0x234) from [<802ed3e8>] (driver_register+0x80/0x14c)
 r8:000000a9 r7:00000000 r6:807620c0 r5:00000006 r4:807576b8
[<802ed368>] (driver_register+0x0/0x14c) from [<802ee2f8>] (platform_driver_register+0x4c/0x60)
[<802ee2ac>] (platform_driver_register+0x0/0x60) from [<80700364>] (sdhci_esdhc_imx_driver_init+0x14/0x1c)
[<80700350>] (sdhci_esdhc_imx_driver_init+0x0/0x1c) from [<8000870c>] (do_one_initcall+0x3c/0x164)
[<800086d0>] (do_one_initcall+0x0/0x164) from [<806d6994>] (kernel_init_freeable+0x104/0x1d0)
[<806d6890>] (kernel_init_freeable+0x0/0x1d0) from [<8052da38>] (kernel_init+0x10/0xec)
[<8052da28>] (kernel_init+0x0/0xec) from [<8000e5d8>] (ret_from_fork+0x14/0x3c)
 r4:00000000 r3:ffffffff
Code: e89da800 e1a0c00d e92dd818 e24cb004 (e5903000)
---[ end trace e9af3588936b63f0 ]---
Kernel panic - not syncing: Fatal exception in interrupt

Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Chris Ball <cjb@laptop.org>
2013-08-24 22:10:10 -04:00
arch MMC highlights for 3.11: 2013-07-10 11:16:00 -07:00
block partitions/msdos: enumerate also AIX LVM partitions 2013-07-09 10:33:28 -07:00
crypto crypto: add lz4 Cryptographic API 2013-07-09 10:33:30 -07:00
Documentation MMC highlights for 3.11: 2013-07-10 11:16:00 -07:00
drivers mmc: sdhci: request irq after sdhci_init() is called 2013-08-24 22:10:10 -04:00
firmware firmware,IB/qib: revert firmware file move 2013-04-05 12:19:39 -07:00
fs Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2013-07-09 18:24:39 -07:00
include MMC highlights for 3.11: 2013-07-10 11:16:00 -07:00
init lib: add support for LZ4-compressed kernel 2013-07-09 10:33:30 -07:00
ipc ipc/sem.c: rename try_atomic_semop() to perform_atomic_semop(), docu update 2013-07-09 10:33:28 -07:00
kernel Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2013-07-09 18:24:39 -07:00
lib Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2013-07-09 18:24:39 -07:00
mm ipc/shmc.c: eliminate ugly 80-col tricks 2013-07-09 10:33:26 -07:00
net Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2013-07-09 18:24:39 -07:00
samples HID: hidraw: warn if userspace headers are outdated 2013-03-27 17:29:18 +01:00
scripts lib: add support for LZ4-compressed kernel 2013-07-09 10:33:30 -07:00
security Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2013-07-09 18:24:39 -07:00
sound IEEE 1394 (FireWire) subsystem changes post v3.10: 2013-07-10 11:02:58 -07:00
tools Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2013-07-09 18:24:39 -07:00
usr lib: add support for LZ4-compressed kernel 2013-07-09 10:33:30 -07:00
virt/kvm KVM fixes for 3.11 2013-07-03 13:21:40 -07:00
.gitignore .gitignore: remove stale entry for generated version.h 2012-12-17 17:15:13 -08:00
.mailmap Viresh has moved 2012-06-20 14:39:36 -07:00
COPYING
CREDITS MAINTAINERS: i8k driver is orphan 2013-04-29 18:28:14 -07:00
Kbuild kbuild: Fix missing system calls check on mips. 2011-11-09 14:37:44 +01:00
Kconfig kbuild: migrate all arch to the kconfig mainmenu upgrade 2010-09-19 22:54:11 -04:00
MAINTAINERS pwm: Changes for v3.11-rc1 2013-07-10 11:14:56 -07:00
Makefile Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial 2013-07-04 11:40:58 -07:00
README Merge branch 'master' into for-next 2012-10-28 19:29:19 +01:00
REPORTING-BUGS Docs: Move ref to Frohwalt Egerer to end of REPORTING-BUGS 2013-04-18 16:55:09 -07:00

        Linux kernel release 3.x <http://kernel.org/>

These are the release notes for Linux version 3.  Read them carefully,
as they tell you what this is all about, explain how to install the
kernel, and what to do if something goes wrong. 

WHAT IS LINUX?

  Linux is a clone of the operating system Unix, written from scratch by
  Linus Torvalds with assistance from a loosely-knit team of hackers across
  the Net. It aims towards POSIX and Single UNIX Specification compliance.

  It has all the features you would expect in a modern fully-fledged Unix,
  including true multitasking, virtual memory, shared libraries, demand
  loading, shared copy-on-write executables, proper memory management,
  and multistack networking including IPv4 and IPv6.

  It is distributed under the GNU General Public License - see the
  accompanying COPYING file for more details. 

ON WHAT HARDWARE DOES IT RUN?

  Although originally developed first for 32-bit x86-based PCs (386 or higher),
  today Linux also runs on (at least) the Compaq Alpha AXP, Sun SPARC and
  UltraSPARC, Motorola 68000, PowerPC, PowerPC64, ARM, Hitachi SuperH, Cell,
  IBM S/390, MIPS, HP PA-RISC, Intel IA-64, DEC VAX, AMD x86-64, AXIS CRIS,
  Xtensa, Tilera TILE, AVR32 and Renesas M32R architectures.

  Linux is easily portable to most general-purpose 32- or 64-bit architectures
  as long as they have a paged memory management unit (PMMU) and a port of the
  GNU C compiler (gcc) (part of The GNU Compiler Collection, GCC). Linux has
  also been ported to a number of architectures without a PMMU, although
  functionality is then obviously somewhat limited.
  Linux has also been ported to itself. You can now run the kernel as a
  userspace application - this is called UserMode Linux (UML).

DOCUMENTATION:

 - There is a lot of documentation available both in electronic form on
   the Internet and in books, both Linux-specific and pertaining to
   general UNIX questions.  I'd recommend looking into the documentation
   subdirectories on any Linux FTP site for the LDP (Linux Documentation
   Project) books.  This README is not meant to be documentation on the
   system: there are much better sources available.

 - There are various README files in the Documentation/ subdirectory:
   these typically contain kernel-specific installation notes for some 
   drivers for example. See Documentation/00-INDEX for a list of what
   is contained in each file.  Please read the Changes file, as it
   contains information about the problems, which may result by upgrading
   your kernel.

 - The Documentation/DocBook/ subdirectory contains several guides for
   kernel developers and users.  These guides can be rendered in a
   number of formats:  PostScript (.ps), PDF, HTML, & man-pages, among others.
   After installation, "make psdocs", "make pdfdocs", "make htmldocs",
   or "make mandocs" will render the documentation in the requested format.

INSTALLING the kernel source:

 - If you install the full sources, put the kernel tarball in a
   directory where you have permissions (eg. your home directory) and
   unpack it:

     gzip -cd linux-3.X.tar.gz | tar xvf -

   or

     bzip2 -dc linux-3.X.tar.bz2 | tar xvf -

   Replace "X" with the version number of the latest kernel.

   Do NOT use the /usr/src/linux area! This area has a (usually
   incomplete) set of kernel headers that are used by the library header
   files.  They should match the library, and not get messed up by
   whatever the kernel-du-jour happens to be.

 - You can also upgrade between 3.x releases by patching.  Patches are
   distributed in the traditional gzip and the newer bzip2 format.  To
   install by patching, get all the newer patch files, enter the
   top level directory of the kernel source (linux-3.X) and execute:

     gzip -cd ../patch-3.x.gz | patch -p1

   or

     bzip2 -dc ../patch-3.x.bz2 | patch -p1

   Replace "x" for all versions bigger than the version "X" of your current
   source tree, _in_order_, and you should be ok.  You may want to remove
   the backup files (some-file-name~ or some-file-name.orig), and make sure
   that there are no failed patches (some-file-name# or some-file-name.rej).
   If there are, either you or I have made a mistake.

   Unlike patches for the 3.x kernels, patches for the 3.x.y kernels
   (also known as the -stable kernels) are not incremental but instead apply
   directly to the base 3.x kernel.  For example, if your base kernel is 3.0
   and you want to apply the 3.0.3 patch, you must not first apply the 3.0.1
   and 3.0.2 patches. Similarly, if you are running kernel version 3.0.2 and
   want to jump to 3.0.3, you must first reverse the 3.0.2 patch (that is,
   patch -R) _before_ applying the 3.0.3 patch. You can read more on this in
   Documentation/applying-patches.txt

   Alternatively, the script patch-kernel can be used to automate this
   process.  It determines the current kernel version and applies any
   patches found.

     linux/scripts/patch-kernel linux

   The first argument in the command above is the location of the
   kernel source.  Patches are applied from the current directory, but
   an alternative directory can be specified as the second argument.

 - Make sure you have no stale .o files and dependencies lying around:

     cd linux
     make mrproper

   You should now have the sources correctly installed.

SOFTWARE REQUIREMENTS

   Compiling and running the 3.x kernels requires up-to-date
   versions of various software packages.  Consult
   Documentation/Changes for the minimum version numbers required
   and how to get updates for these packages.  Beware that using
   excessively old versions of these packages can cause indirect
   errors that are very difficult to track down, so don't assume that
   you can just update packages when obvious problems arise during
   build or operation.

BUILD directory for the kernel:

   When compiling the kernel, all output files will per default be
   stored together with the kernel source code.
   Using the option "make O=output/dir" allow you to specify an alternate
   place for the output files (including .config).
   Example:

     kernel source code: /usr/src/linux-3.X
     build directory:    /home/name/build/kernel

   To configure and build the kernel, use:

     cd /usr/src/linux-3.X
     make O=/home/name/build/kernel menuconfig
     make O=/home/name/build/kernel
     sudo make O=/home/name/build/kernel modules_install install

   Please note: If the 'O=output/dir' option is used, then it must be
   used for all invocations of make.

CONFIGURING the kernel:

   Do not skip this step even if you are only upgrading one minor
   version.  New configuration options are added in each release, and
   odd problems will turn up if the configuration files are not set up
   as expected.  If you want to carry your existing configuration to a
   new version with minimal work, use "make oldconfig", which will
   only ask you for the answers to new questions.

 - Alternative configuration commands are:

     "make config"      Plain text interface.

     "make menuconfig"  Text based color menus, radiolists & dialogs.

     "make nconfig"     Enhanced text based color menus.

     "make xconfig"     X windows (Qt) based configuration tool.

     "make gconfig"     X windows (Gtk) based configuration tool.

     "make oldconfig"   Default all questions based on the contents of
                        your existing ./.config file and asking about
                        new config symbols.

     "make silentoldconfig"
                        Like above, but avoids cluttering the screen
                        with questions already answered.
                        Additionally updates the dependencies.

     "make olddefconfig"
                        Like above, but sets new symbols to their default
                        values without prompting.

     "make defconfig"   Create a ./.config file by using the default
                        symbol values from either arch/$ARCH/defconfig
                        or arch/$ARCH/configs/${PLATFORM}_defconfig,
                        depending on the architecture.

     "make ${PLATFORM}_defconfig"
                        Create a ./.config file by using the default
                        symbol values from
                        arch/$ARCH/configs/${PLATFORM}_defconfig.
                        Use "make help" to get a list of all available
                        platforms of your architecture.

     "make allyesconfig"
                        Create a ./.config file by setting symbol
                        values to 'y' as much as possible.

     "make allmodconfig"
                        Create a ./.config file by setting symbol
                        values to 'm' as much as possible.

     "make allnoconfig" Create a ./.config file by setting symbol
                        values to 'n' as much as possible.

     "make randconfig"  Create a ./.config file by setting symbol
                        values to random values.

     "make localmodconfig" Create a config based on current config and
                           loaded modules (lsmod). Disables any module
                           option that is not needed for the loaded modules.

                           To create a localmodconfig for another machine,
                           store the lsmod of that machine into a file
                           and pass it in as a LSMOD parameter.

                   target$ lsmod > /tmp/mylsmod
                   target$ scp /tmp/mylsmod host:/tmp

                   host$ make LSMOD=/tmp/mylsmod localmodconfig

                           The above also works when cross compiling.

     "make localyesconfig" Similar to localmodconfig, except it will convert
                           all module options to built in (=y) options.

   You can find more information on using the Linux kernel config tools
   in Documentation/kbuild/kconfig.txt.

 - NOTES on "make config":

    - Having unnecessary drivers will make the kernel bigger, and can
      under some circumstances lead to problems: probing for a
      nonexistent controller card may confuse your other controllers

    - Compiling the kernel with "Processor type" set higher than 386
      will result in a kernel that does NOT work on a 386.  The
      kernel will detect this on bootup, and give up.

    - A kernel with math-emulation compiled in will still use the
      coprocessor if one is present: the math emulation will just
      never get used in that case.  The kernel will be slightly larger,
      but will work on different machines regardless of whether they
      have a math coprocessor or not.

    - The "kernel hacking" configuration details usually result in a
      bigger or slower kernel (or both), and can even make the kernel
      less stable by configuring some routines to actively try to
      break bad code to find kernel problems (kmalloc()).  Thus you
      should probably answer 'n' to the questions for "development",
      "experimental", or "debugging" features.

COMPILING the kernel:

 - Make sure you have at least gcc 3.2 available.
   For more information, refer to Documentation/Changes.

   Please note that you can still run a.out user programs with this kernel.

 - Do a "make" to create a compressed kernel image. It is also
   possible to do "make install" if you have lilo installed to suit the
   kernel makefiles, but you may want to check your particular lilo setup first.

   To do the actual install, you have to be root, but none of the normal
   build should require that. Don't take the name of root in vain.

 - If you configured any of the parts of the kernel as `modules', you
   will also have to do "make modules_install".

 - Verbose kernel compile/build output:

   Normally, the kernel build system runs in a fairly quiet mode (but not
   totally silent).  However, sometimes you or other kernel developers need
   to see compile, link, or other commands exactly as they are executed.
   For this, use "verbose" build mode.  This is done by inserting
   "V=1" in the "make" command.  E.g.:

     make V=1 all

   To have the build system also tell the reason for the rebuild of each
   target, use "V=2".  The default is "V=0".

 - Keep a backup kernel handy in case something goes wrong.  This is 
   especially true for the development releases, since each new release
   contains new code which has not been debugged.  Make sure you keep a
   backup of the modules corresponding to that kernel, as well.  If you
   are installing a new kernel with the same version number as your
   working kernel, make a backup of your modules directory before you
   do a "make modules_install".

   Alternatively, before compiling, use the kernel config option
   "LOCALVERSION" to append a unique suffix to the regular kernel version.
   LOCALVERSION can be set in the "General Setup" menu.

 - In order to boot your new kernel, you'll need to copy the kernel
   image (e.g. .../linux/arch/i386/boot/bzImage after compilation)
   to the place where your regular bootable kernel is found. 

 - Booting a kernel directly from a floppy without the assistance of a
   bootloader such as LILO, is no longer supported.

   If you boot Linux from the hard drive, chances are you use LILO, which
   uses the kernel image as specified in the file /etc/lilo.conf.  The
   kernel image file is usually /vmlinuz, /boot/vmlinuz, /bzImage or
   /boot/bzImage.  To use the new kernel, save a copy of the old image
   and copy the new image over the old one.  Then, you MUST RERUN LILO
   to update the loading map!! If you don't, you won't be able to boot
   the new kernel image.

   Reinstalling LILO is usually a matter of running /sbin/lilo. 
   You may wish to edit /etc/lilo.conf to specify an entry for your
   old kernel image (say, /vmlinux.old) in case the new one does not
   work.  See the LILO docs for more information. 

   After reinstalling LILO, you should be all set.  Shutdown the system,
   reboot, and enjoy!

   If you ever need to change the default root device, video mode,
   ramdisk size, etc.  in the kernel image, use the 'rdev' program (or
   alternatively the LILO boot options when appropriate).  No need to
   recompile the kernel to change these parameters. 

 - Reboot with the new kernel and enjoy. 

IF SOMETHING GOES WRONG:

 - If you have problems that seem to be due to kernel bugs, please check
   the file MAINTAINERS to see if there is a particular person associated
   with the part of the kernel that you are having trouble with. If there
   isn't anyone listed there, then the second best thing is to mail
   them to me (torvalds@linux-foundation.org), and possibly to any other
   relevant mailing-list or to the newsgroup.

 - In all bug-reports, *please* tell what kernel you are talking about,
   how to duplicate the problem, and what your setup is (use your common
   sense).  If the problem is new, tell me so, and if the problem is
   old, please try to tell me when you first noticed it.

 - If the bug results in a message like

     unable to handle kernel paging request at address C0000010
     Oops: 0002
     EIP:   0010:XXXXXXXX
     eax: xxxxxxxx   ebx: xxxxxxxx   ecx: xxxxxxxx   edx: xxxxxxxx
     esi: xxxxxxxx   edi: xxxxxxxx   ebp: xxxxxxxx
     ds: xxxx  es: xxxx  fs: xxxx  gs: xxxx
     Pid: xx, process nr: xx
     xx xx xx xx xx xx xx xx xx xx

   or similar kernel debugging information on your screen or in your
   system log, please duplicate it *exactly*.  The dump may look
   incomprehensible to you, but it does contain information that may
   help debugging the problem.  The text above the dump is also
   important: it tells something about why the kernel dumped code (in
   the above example, it's due to a bad kernel pointer). More information
   on making sense of the dump is in Documentation/oops-tracing.txt

 - If you compiled the kernel with CONFIG_KALLSYMS you can send the dump
   as is, otherwise you will have to use the "ksymoops" program to make
   sense of the dump (but compiling with CONFIG_KALLSYMS is usually preferred).
   This utility can be downloaded from
   ftp://ftp.<country>.kernel.org/pub/linux/utils/kernel/ksymoops/ .
   Alternatively, you can do the dump lookup by hand:

 - In debugging dumps like the above, it helps enormously if you can
   look up what the EIP value means.  The hex value as such doesn't help
   me or anybody else very much: it will depend on your particular
   kernel setup.  What you should do is take the hex value from the EIP
   line (ignore the "0010:"), and look it up in the kernel namelist to
   see which kernel function contains the offending address.

   To find out the kernel function name, you'll need to find the system
   binary associated with the kernel that exhibited the symptom.  This is
   the file 'linux/vmlinux'.  To extract the namelist and match it against
   the EIP from the kernel crash, do:

     nm vmlinux | sort | less

   This will give you a list of kernel addresses sorted in ascending
   order, from which it is simple to find the function that contains the
   offending address.  Note that the address given by the kernel
   debugging messages will not necessarily match exactly with the
   function addresses (in fact, that is very unlikely), so you can't
   just 'grep' the list: the list will, however, give you the starting
   point of each kernel function, so by looking for the function that
   has a starting address lower than the one you are searching for but
   is followed by a function with a higher address you will find the one
   you want.  In fact, it may be a good idea to include a bit of
   "context" in your problem report, giving a few lines around the
   interesting one. 

   If you for some reason cannot do the above (you have a pre-compiled
   kernel image or similar), telling me as much about your setup as
   possible will help.  Please read the REPORTING-BUGS document for details.

 - Alternatively, you can use gdb on a running kernel. (read-only; i.e. you
   cannot change values or set break points.) To do this, first compile the
   kernel with -g; edit arch/i386/Makefile appropriately, then do a "make
   clean". You'll also need to enable CONFIG_PROC_FS (via "make config").

   After you've rebooted with the new kernel, do "gdb vmlinux /proc/kcore".
   You can now use all the usual gdb commands. The command to look up the
   point where your system crashed is "l *0xXXXXXXXX". (Replace the XXXes
   with the EIP value.)

   gdb'ing a non-running kernel currently fails because gdb (wrongly)
   disregards the starting offset for which the kernel is compiled.