This patch adds a new configuration option, which adds support for a new
early_param which gets checked in arch/x86/kernel/setup_{32,64}.c:setup_arch()
to decide wether OHCI-1394 FireWire controllers should be initialized and
enabled for physical DMA access to allow remote debugging of early problems
like issues ACPI or other subsystems which are executed very early.
If the config option is not enabled, no code is changed, and if the boot
paramenter is not given, no new code is executed, and independent of that,
all new code is freed after boot, so the config option can be even enabled
in standard, non-debug kernels.
With specialized tools, it is then possible to get debugging information
from machines which have no serial ports (notebooks) such as the printk
buffer contents, or any data which can be referenced from global pointers,
if it is stored below the 4GB limit and even memory dumps of of the physical
RAM region below the 4GB limit can be taken without any cooperation from the
CPU of the host, so the machine can be crashed early, it does not matter.
In the extreme, even kernel debuggers can be accessed in this way. I wrote
a small kgdb module and an accompanying gdb stub for FireWire which allows
to gdb to talk to kgdb using remote remory reads and writes over FireWire.
An version of the gdb stub fore FireWire is able to read all global data
from a system which is running a a normal kernel without any kernel debugger,
without any interruption or support of the system's CPU. That way, e.g. the
task struct and so on can be read and even manipulated when the physical DMA
access is granted.
A HOWTO is included in this patch, in Documentation/debugging-via-ohci1394.txt
and I've put a copy online at
ftp://ftp.suse.de/private/bk/firewire/docs/debugging-via-ohci1394.txt
It also has links to all the tools which are available to make use of it
another copy of it is online at:
ftp://ftp.suse.de/private/bk/firewire/kernel/ohci1394_dma_early-v2.diff
Signed-Off-By: Bernhard Kaindl <bk@suse.de>
Tested-By: Thomas Renninger <trenn@suse.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
During the work on the x86 32 and 64 bit backtrace code I found it useful
to have a simple test module to test a process and irq context backtrace.
Since the existing backtrace code was buggy, I figure it might be useful
to have such a test module in the kernel so that maybe we can even
detect such bugs earlier..
[ mingo@elte.hu: build fix ]
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
introduce the "asmregparm" calling convention: for functions
implemented in assembly with a fixed regparm input parameters
calling convention.
mark the semaphore and rwsem slowpath functions with that.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Here is a quick and naive smoke test for kprobes. This is intended to
just verify if some unrelated change broke the *probes subsystem. It is
self contained, architecture agnostic and isn't of any great use by itself.
This needs to be built in the kernel and runs a basic set of tests to
verify if kprobes, jprobes and kretprobes run fine on the kernel. In case
of an error, it'll print out a message with a "BUG" prefix.
This is a start; we intend to add more tests to this bucket over time.
Thanks to Jim Keniston and Masami Hiramatsu for comments and suggestions.
Tested on x86 (32/64) and powerpc.
Signed-off-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Acked-by: Masami Hiramatsu <mhiramat@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6.25: (1470 commits)
[IPV6] ADDRLABEL: Fix double free on label deletion.
[PPP]: Sparse warning fixes.
[IPV4] fib_trie: remove unneeded NULL check
[IPV4] fib_trie: More whitespace cleanup.
[NET_SCHED]: Use nla_policy for attribute validation in ematches
[NET_SCHED]: Use nla_policy for attribute validation in actions
[NET_SCHED]: Use nla_policy for attribute validation in classifiers
[NET_SCHED]: Use nla_policy for attribute validation in packet schedulers
[NET_SCHED]: sch_api: introduce constant for rate table size
[NET_SCHED]: Use typeful attribute parsing helpers
[NET_SCHED]: Use typeful attribute construction helpers
[NET_SCHED]: Use NLA_PUT_STRING for string dumping
[NET_SCHED]: Use nla_nest_start/nla_nest_end
[NET_SCHED]: Propagate nla_parse return value
[NET_SCHED]: act_api: use PTR_ERR in tcf_action_init/tcf_action_get
[NET_SCHED]: act_api: use nlmsg_parse
[NET_SCHED]: act_api: fix netlink API conversion bug
[NET_SCHED]: sch_netem: use nla_parse_nested_compat
[NET_SCHED]: sch_atm: fix format string warning
[NETNS]: Add namespace for ICMP replying code.
...
* git://git.kernel.org/pub/scm/linux/kernel/git/sam/kbuild: (79 commits)
Remove references to "make dep"
kconfig: document use of HAVE_*
Introduce new section reference annotations tags: __ref, __refdata, __refconst
kbuild: warn about ld added unique sections
kbuild: add verbose option to Section mismatch reporting in modpost
kconfig: tristate choices with mixed tristate and boolean values
asm-generic/vmlix.lds.h: simplify __mem{init,exit}* dependencies
remove __attribute_used__
kbuild: support ARCH=x86 in buildtar
kconfig: remove "enable"
kbuild: simplified warning report in modpost
kbuild: introduce a few helpers in modpost
kbuild: use simpler section mismatch warnings in modpost
kbuild: link vmlinux.o before kallsyms passes
kbuild: introduce new option to enhance section mismatch analysis
Use separate sections for __dev/__cpu/__mem code/data
compiler.h: introduce __section()
all archs: consolidate init and exit sections in vmlinux.lds.h
kbuild: check section names consistently in modpost
kbuild: introduce blacklisting in modpost
...
Before pushing pcounter to Linus tree, I would like to make some adjustments.
Goal is to reduce kernel text size, by unlining too big functions.
When a pcounter is bound to a statically defined per_cpu variable,
we define two small helpers functions. (No more folding function
using the fat for_each_possible_cpu(cpu) ... )
static DEFINE_PER_CPU(int, NAME##_pcounter_values);
static void NAME##_pcounter_add(struct pcounter *self, int val)
{
__get_cpu_var(NAME##_pcounter_values) += val;
}
static int NAME##_pcounter_getval(const struct pcounter *self, int cpu)
{
return per_cpu(NAME##_pcounter_values, cpu);
}
Fast path is therefore unchanged, while folding/alloc/free is now unlined.
This saves 228 bytes on i386
Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This just generalises what was introduced by Eric Dumazet for the struct proto
inuse field in 286ab3d460:
[NET]: Define infrastructure to keep 'inuse' changes in an efficent SMP/NUMA way.
Please look at the comment in there to see the rationale.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
If the config option CONFIG_SECTION_MISMATCH is not set and
we see a Section mismatch present the following to the user:
modpost: Found 1 section mismatch(es).
To see additional details select "Enable full Section mismatch analysis"
in the Kernel Hacking menu (CONFIG_SECTION_MISMATCH).
If the option CONFIG_SECTION_MISMATCH is selected
then be verbose in the Section mismatch reporting from mdopost.
Sample outputs:
WARNING: o-x86_64/vmlinux.o(.text+0x7396): Section mismatch in reference from the function discover_ebda() to the variable .init.data:ebda_addr
The function discover_ebda() references
the variable __initdata ebda_addr.
This is often because discover_ebda lacks a __initdata
annotation or the annotation of ebda_addr is wrong.
WARNING: o-x86_64/vmlinux.o(.data+0x74d58): Section mismatch in reference from the variable pci_serial_quirks to the function .devexit.text:pci_plx9050_exit()
The variable pci_serial_quirks references
the function __devexit pci_plx9050_exit()
If the reference is valid then annotate the
variable with __exit* (see linux/init.h) or name the variable:
*driver, *_template, *_timer, *_sht, *_ops, *_probe, *_probe_one, *_console,
WARNING: o-x86_64/vmlinux.o(__ksymtab+0x630): Section mismatch in reference from the variable __ksymtab_arch_register_cpu to the function .cpuinit.text:arch_register_cpu()
The symbol arch_register_cpu is exported and annotated __cpuinit
Fix this by removing the __cpuinit annotation of arch_register_cpu or drop the export.
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Setting the option DEBUG_SECTION_MISMATCH will
report additional section mismatch'es but this
should in the end makes it possible to get rid of
all of them.
See help text in lib/Kconfig.debug for details.
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
SCSI sg table allocation has a maximum size (of SCSI_MAX_SG_SEGMENTS,
currently 128) and this will cause a BUG_ON() in SCSI if something
tries an allocation over it. This patch adds a size limit to the
chaining allocator to allow the specification of the maximum
allocation size for chaining, so we always chain in units of the
maximum SCSI allocation size.
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Manually doing chained sg lists is not trivial, so add some helpers
to make sure that drivers get it right.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
LatencyTOP kernel infrastructure; it measures latencies in the
scheduler and tracks it system wide and per process.
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
All kobjects require a dynamically allocated name now. We no longer
need to keep track if the name is statically assigned, we can just
unconditionally free() all kobject names on cleanup.
Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
There are no in-kernel users of kobject_unregister() so it should be
removed.
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
There is no need for kobject_unregister() anymore, thanks to Kay's
kobject cleanup changes, so replace all instances of it with
kobject_put().
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
We save the current state in the object itself, so we can do proper
cleanup when the last reference is dropped.
If the initial reference is dropped, the object will be removed from
sysfs if needed, if an "add" event was sent, "remove" will be send, and
the allocated resources are released.
This allows us to clean up some driver core usage as well as allowing us
to do other such changes to the rest of the kernel.
Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
No one is calling this anymore, so just remove it and hard-code the one
internal-use of it.
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The function is no longer used by anyone in the kernel, and it prevents
the proper sending of the kobject uevent after the needed files are set
up by the caller. kobject_init_and_add() can be used in its place.
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Now that the old kobject_init() function is gone, rename
kobject_init_ng() to kobject_init() to clean up the namespace.
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The old kobject_init() function is on longer in use, so let us remove it
from the public scope (kset mess in the kobject.c file still uses it,
but that can be cleaned up later very simply.)
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Now that the old kobject_add() function is gone, rename kobject_add_ng()
to kobject_add() to clean up the namespace.
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
