Re: [Crash-utility] Kernel Crash Analysis on Android
by Shankar, AmarX
Hi Dave,
Thanks for your info regarding kexec tool.
I am unable to download kexec from below link.
http://www.kernel.org/pub/linux/kernel/people/horms/kexec-tools/kexec-too...
It says HTTP 404 Page Not Found.
Could you please guide me on this?
Thanks & Regards,
Amar Shankar
> On Wed, Mar 21, 2012 at 06:00:00PM +0000, Shankar, AmarX wrote:
>
> > I want to do kernel crash Analysis on Android Merrifield Target.
> >
> > Could someone please help me how to do it?
>
> Merrifield is pretty much similar than Medfield, e.g it has x86 core. So I
> guess you can follow the instructions how to setup kdump on x86 (see
> Documentation/kdump/kdump.txt) unless you already have that configured.
>
> crash should support this directly presuming you have vmlinux/vmcore files to
> feed it. You can configure crash to support x86 on x86_64 host by running:
>
> % make target=X86
> & make
>
> (or something along those lines).
Right -- just the first make command will suffice, i.e., when running
on an x86_64 host:
$ wget http://people.redhat.com/anderson/crash-6.0.4.tar.gz
$ tar xzf crash-6.0.4.tar.gz
...
$ cd crash-6.0.4
$ make target=X86
...
$ ./crash <path-to>/vmlinux <path-to>/vmcore
Dave
From: Shankar, AmarX
Sent: Wednesday, March 21, 2012 11:30 PM
To: 'crash-utility(a)redhat.com'
Subject: Kernel Crash Analysis on Android
Hi,
I want to do kernel crash Analysis on Android Merrifield Target.
Could someone please help me how to do it?
Thanks & Regards,
Amar Shankar
1 year
[PATCH] kmem, snap: iomem/ioport display and vmcore snapshot support
by HATAYAMA Daisuke
Some days ago I was in a situation that I had to convert vmcore in
kvmdump format into ELF since some extension module we have locally
can be used only on relatively old crash utility, around version 4,
but such old crash utility cannot handle kvmdump format.
To do the conversion in handy, I used snap command with some modifications
so that it tries to use iomem information in vmcore instead of host's
/proc/iomem. This patch is its cleaned-up version.
In this development, I naturally got down to also making an interface
for an access to resource objects, and so together with the snap
command's patch, I also extended kmem command for iomem/ioport
support. Actually:
kmem -r displays /proc/iomem
crash> kmem -r
00000000-0000ffff : reserved
00010000-0009dbff : System RAM
0009dc00-0009ffff : reserved
000c0000-000c7fff : Video ROM
...
and kmem -R displays /proc/ioport
crash> kmem -R
0000-001f : dma1
0020-0021 : pic1
0040-0043 : timer0
0050-0053 : timer1
...
Looking into old version of kernel source code back, resource structure
has been unchanged since linux-2.4.0. I borrowed the way of walking on
resouce tree in this patch from the lastest v3.3-rc series, but I
guess the logic is also applicable to old kernels. I expect Dave's
regression testsuite.
Also, there would be another command more sutable for iomem/ioport.
If necessay, I'll repost the patch.
---
HATAYAMA Daisuke (4):
Add vmcore snapshot support
Add kmem -r and -R options
Add dump iomem/ioport functions; a helper for resource objects
Add a helper function for iterating resource objects
defs.h | 9 ++++
extensions/snap.c | 54 ++++++++++++++++++++++-
help.c | 2 +
memory.c | 122 +++++++++++++++++++++++++++++++++++++++++++++++++++--
4 files changed, 180 insertions(+), 7 deletions(-)
--
Thanks.
HATAYAMA Daisuke
1 year
Re: [Crash-utility] question about phys_base
by Dave Anderson
----- Original Message -----
> >
> > OK, so then I don't understand what you mean by "may be the same"?
> >
> > You didn't answer my original question, but if I understand you correctly,
> > it would be impossible for the qemu host to create a PT_LOAD segment that
> > describes an x86_64 guest's __START_KERNEL_map region, because the host
> > doesn't know that what kind of kernel the guest is running.
>
> Yes. Even if the guest is linux, it is still impossible to do it. Because
> the guest maybe in the second kernel.
>
> qemu-dump walks all guest's page table and collect virtual address and
> physical address mapping. If the page is not used by guest, the virtual is set
> to 0. I create PT_LOAD according to such mapping. So if the guest is linux,
> there may be a PT_LOAD segment that describes __START_KERNEL_map region.
> But the information stored in PT_LOAD maybe for the second kernel. If crash
> uses it, crash will see the second kernel, not the first kernel.
Just to be clear -- what do you mean by the "second" kernel? Do you
mean that a guest kernel crashed guest, and did a kdump operation,
and that second kdump kernel failed somehow, and now you're trying
to do a "virsh dump" on the kdump kernel?
Dave
1 year
question about phys_base
by Wen Congyang
Hi, Dave
I am implementing a new dump command in the qemu. The vmcore's
format is elf(like kdump). And I try to provide phys_base in
the PT_LOAD. But if the os uses the first vcpu do kdump, the
value of phys_base is wrong.
I find a function x86_64_virt_phys_base() in crash's code.
Is it OK to call this function first? If the function
successes, we do not calculate phys_base according to PT_LOAD.
Thanks
Wen Congyang
1 year
[PATCH] runq: search current task's runqueue explicitly
by HATAYAMA Daisuke
Currently, runq sub-command doesn't consider CFS runqueue's current
task removed from CFS runqueue. Due to this, the remaining CFS
runqueus that follow the current task's is not displayed. This patch
fixes this by making runq sub-command search current task's runqueue
explicitly.
Note that CFS runqueue exists for each task group, and so does CFS
runqueue's current task, and the above search needs to be done
recursively.
Test
====
On vmcore I made 7 task groups:
root group --- A --- AA --- AAA
+ +- AAB
|
+- AB --- ABA
+- ABB
and then I ran three CPU bound tasks, which is exactly the same as
int main(void) { for (;;) continue; return 0; }
for each task group, including root group; so total 24 tasks. For
readability, I annotated each task name with its belonging group name.
For example, loop.ABA belongs to task group ABA.
Look at CPU0 collumn below. [before] lacks 8 tasks and [after]
successfully shows all tasks on the runqueue, which is identical to
the result of [sched debug] that is expected to ouput correct result.
I'll send this vmcore later.
[before]
crash> runq | cat
CPU 0 RUNQUEUE: ffff88000a215f80
CURRENT: PID: 28263 TASK: ffff880037aaa040 COMMAND: "loop.ABA"
RT PRIO_ARRAY: ffff88000a216098
[no tasks queued]
CFS RB_ROOT: ffff88000a216010
[120] PID: 28262 TASK: ffff880037cc40c0 COMMAND: "loop.ABA"
<cut>
[after]
crash_fix> runq
CPU 0 RUNQUEUE: ffff88000a215f80
CURRENT: PID: 28263 TASK: ffff880037aaa040 COMMAND: "loop.ABA"
RT PRIO_ARRAY: ffff88000a216098
[no tasks queued]
CFS RB_ROOT: ffff88000a216010
[120] PID: 28262 TASK: ffff880037cc40c0 COMMAND: "loop.ABA"
[120] PID: 28271 TASK: ffff8800787a8b40 COMMAND: "loop.ABB"
[120] PID: 28272 TASK: ffff880037afd580 COMMAND: "loop.ABB"
[120] PID: 28245 TASK: ffff8800785e8b00 COMMAND: "loop.AB"
[120] PID: 28246 TASK: ffff880078628ac0 COMMAND: "loop.AB"
[120] PID: 28241 TASK: ffff880078616b40 COMMAND: "loop.AA"
[120] PID: 28239 TASK: ffff8800785774c0 COMMAND: "loop.AA"
[120] PID: 28240 TASK: ffff880078617580 COMMAND: "loop.AA"
[120] PID: 28232 TASK: ffff880079b5d4c0 COMMAND: "loop.A"
<cut>
[sched debug]
crash> runq -d
CPU 0
[120] PID: 28232 TASK: ffff880079b5d4c0 COMMAND: "loop.A"
[120] PID: 28239 TASK: ffff8800785774c0 COMMAND: "loop.AA"
[120] PID: 28240 TASK: ffff880078617580 COMMAND: "loop.AA"
[120] PID: 28241 TASK: ffff880078616b40 COMMAND: "loop.AA"
[120] PID: 28245 TASK: ffff8800785e8b00 COMMAND: "loop.AB"
[120] PID: 28246 TASK: ffff880078628ac0 COMMAND: "loop.AB"
[120] PID: 28262 TASK: ffff880037cc40c0 COMMAND: "loop.ABA"
[120] PID: 28263 TASK: ffff880037aaa040 COMMAND: "loop.ABA"
[120] PID: 28271 TASK: ffff8800787a8b40 COMMAND: "loop.ABB"
[120] PID: 28272 TASK: ffff880037afd580 COMMAND: "loop.ABB"
<cut>
Diff stat
=========
defs.h | 1 +
task.c | 37 +++++++++++++++++--------------------
2 files changed, 18 insertions(+), 20 deletions(-)
Thanks.
HATAYAMA, Daisuke
1 year
[RFC] makedumpfile, crash: LZO compression support
by HATAYAMA Daisuke
Hello,
This is a RFC patch set that adds LZO compression support to
makedumpfile and crash utility. LZO is as good as in size but by far
better in speed than ZLIB, leading to reducing down time during
generation of crash dump and refiltering.
How to build:
1. Get LZO library, which is provided as lzo-devel package on recent
linux distributions, and is also available on author's website:
http://www.oberhumer.com/opensource/lzo/.
2. Apply the patch set to makedumpfile v1.4.0 and crash v6.0.0.
3. Build both using make. But for crash, do the following now:
$ make CFLAGS="-llzo2"
How to use:
I've newly used -l option for lzo compression in this patch. So for
example, do as follows:
$ makedumpfile -l vmcore dumpfile
$ crash vmlinux dumpfile
Request of configure-like feature for crash utility:
I would like configure-like feature on crash utility for users to
select wheather to add LZO feature actually or not in build-time,
that is: ./configure --enable-lzo or ./configure --disable-lzo.
The reason is that support staff often downloads and installs the
latest version of crash utility on machines where lzo library is not
provided.
Looking at the source code, it looks to me that crash does some kind
of configuration processing in a local manner, around configure.c,
and I guess it's difficult to use autoconf tools directly.
Or is there another better way?
Performance Comparison:
Sample Data
Ideally, I must have measured the performance for many enough
vmcores generated from machines that was actually running, but now
I don't have enough sample vmcores, I couldn't do so. So this
comparison doesn't answer question on I/O time improvement. This
is TODO for now.
Instead, I choosed worst and best cases regarding compression
ratio and speed only. Specifically, the former is /dev/urandom and
the latter is /dev/zero.
I get the sample data of 10MB, 100MB and 1GB by doing like this:
$ dd bs=4096 count=$((1024*1024*1024/4096)) if=/dev/urandom of=urandom.1GB
How to measure
Then I performed compression for each block, 4096 bytes, and
measured total compression time and output size. See attached
mycompress.c.
Result
See attached file result.txt.
Discussion
For both kinds of data, lzo's compression was considerably quicker
than zlib's. Compression ratio is about 37% for urandom data, and
about 8.5% for zero data. Actual situation of physical memory
would be in between the two cases, and so I guess average
compression time ratio is between 37% and 8.5%.
Although beyond the topic of this patch set, we can estimate worst
compression time on more data size since compression is performed
block size wise and the compression time increases
linearly. Estimated worst time on 2TB memory is about 15 hours for
lzo and about 40 hours for zlib. In this case, compressed data
size is larger than the original, so they are really not used,
compression time is fully meaningless. I think compression must be
done in parallel, and I'll post such patch later.
Diffstat
* makedumpfile
diskdump_mod.h | 3 +-
makedumpfile.c | 98 +++++++++++++++++++++++++++++++++++++++++++++++++------
makedumpfile.h | 12 +++++++
3 files changed, 101 insertions(+), 12 deletions(-)
* crash
defs.h | 1 +
diskdump.c | 20 +++++++++++++++++++-
diskdump.h | 3 ++-
3 files changed, 22 insertions(+), 2 deletions(-)
TODO
* evaluation including I/O time using actual vmcores
Thanks.
HATAYAMA, Daisuke
1 year
Re: [Crash-utility] [RFI] Support Fujitsu's sadump dump format
by tachibana＠mxm.nes.nec.co.jp
Hi Hatayama-san,
On 2011/06/29 12:12:18 +0900, HATAYAMA Daisuke <d.hatayama(a)jp.fujitsu.com> wrote:
> From: Dave Anderson <anderson(a)redhat.com>
> Subject: Re: [Crash-utility] [RFI] Support Fujitsu's sadump dump format
> Date: Tue, 28 Jun 2011 08:57:42 -0400 (EDT)
>
> >
> >
> > ----- Original Message -----
> >> Fujitsu has stand-alone dump mechanism based on firmware level
> >> functionality, which we call SADUMP, in short.
> >>
> >> We've maintained utility tools internally but now we're thinking that
> >> the best is crash utility and makedumpfile supports the sadump format
> >> for the viewpoint of both portability and maintainability.
> >>
> >> We'll be of course responsible for its maintainance in a continuous
> >> manner. The sadump dump format is very similar to diskdump format and
> >> so kdump (compressed) format, so we estimate patch set would be a
> >> relatively small size.
> >>
> >> Could you tell me whether crash utility and makedumpfile can support
> >> the sadump format? If OK, we'll start to make patchset.
I think it's not bad to support sadump by makedumpfile. However I have
several questions.
- Do you want to use makedumpfile to make an existing file that sadump has
dumped small?
- It isn't possible to support the same form as kdump-compressed format
now, is it?
- When the information that makedumpfile reads from a note of /proc/vmcore
(or a header of kdump-compressed format) is added by an extension of
makedumpfile, do you need to modify sadump?
Thanks
tachibana
> >
> > Sure, yes, the crash utility can always support another dumpfile format.
> >
>
> Thanks. It helps a lot.
>
> > It's unclear to me how similar SADUMP is to diskdump/compressed-kdump.
> > Does your internal version patch diskdump.c, or do you maintain your
> > own "sadump.c"? I ask because if your patchset is at all intrusive,
> > I'd prefer it be kept in its own file, primarily for maintainability,
> > but also because SADUMP is essentially a black-box to anybody outside
> > Fujitsu.
>
> What I meant when I used ``similar'' is both literally and
> logically. The format consists of diskdump header-like header, two
> kinds of bitmaps used for the same purpose as those in diskump format,
> and memory data. They can be handled in common with the existing data
> structure, diskdump_data, non-intrusively, so I hope they are placed
> in diskdump.c.
>
> On the other hand, there's a code to be placed at such specific
> area. sadump is triggered depending on kdump's progress and so
> register values to be contained in vmcore varies according to the
> progress: If crash_notes has been initialized when sadump is
> triggered, sadump packs the register values in crash_notes; if not
> yet, packs registers gathered by firmware. This is sadump specific
> processing, so I think putting it in specific sadump.c file is a
> natural and reasonable choise.
>
> Anyway, I have not made any patch set for this. I'll post a patch set
> when I complete.
>
> Again, thanks a lot for the positive answer.
>
> Thanks.
> HATAYAMA, Daisuke
>
>
> _______________________________________________
> kexec mailing list
> kexec(a)lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/kexec
1 year
Adding a new command rbtree
by qiaonuohan
Hello HATAYAMA,
I am trying to add a new command can be used to display rbtree and
radix tree. After some investigation, I find they are similar to the
build-in command "list". So I send this mail to ask your opinion about
making cmd_list to be similar to the command "struct/union/*".
Another thing needed to be inquired is about the style of displaying
tree. I will list some of my thought, and some suggestion will be glad
to get from you.
1.
NODE ... : ...
NODE ... : ...
NODE ... : ...
NODE ... : ...
NODE ... : ...
NODE ... : ...
This style can not indicate whether the leaf is left or right. And with
a big depth, the output may be ugly. So I do not like it.
2.
l - left child
r - right child
root NODE ... : ...
l NODE ... : ...
ll NODE ... : ...
lll NODE ... : ...
lr NODE ... : ...
r NODE ... : ...
Of course, in radix tree, l & r will be changed to some string that can
indicate the child of a node. Still, with a big depth, the line will be
too long and ugly.
3.
root NODE addr1 : ...
addr1 l NODE addr2 : ...
addr2 l NODE addr3 : ...
addr3 l NODE addr4 : ...
addr2 r NODE addr5 : ...
addr1 r NODE addr6 : ...
(l & r have the same meaning with the one in the 2.)
Surely, I prefer the the third one. What do you think? Or eliminating
the information indicating position is acceptable?
--
--
Regards
Qiao Nuohan
12 years, 5 months
[ANNOUNCE] crash version 6.0.7 is available
by Dave Anderson
Download from: http://people.redhat.com/anderson
Changelog:
- Enhanced the "search" command to allow the searched-for value
to be entered as a crash (expression) or a kernel symbol name.
The resultant value of an (expression) or kernel symbol value
must fit into in the designated value size if -w or -h are used,
and neither variant may be used with the -c option. If found,
both the resultant value and the argument input string will be
displayed next to the target address(es).
(anderson(a)redhat.com)
- Added a new "search -t" option that will restrict the search
to the kernel stack pages of all tasks. If one or more matches
are found in a task's kernel stack, the output is preceded
with a task-identifying header.
(anderson(a)redhat.com)
- Fix for the s390x "bt -[tT]" options when run on an active task
on a live system. Without the patch, the options fail with the
message "bt: invalid/stale stack pointer for this task: 0".
(anderson(a)redhat.com)
- Fix for s390x "vm -p" option, which may show invalid user to
physical address translation data if a page is not mapped.
Without the patch, a page's translation may indicate
"<address> SWAP: (unknown swap location) OFFSET: 0",
or show an incorrect swap offset on an actual swap device.
(anderson(a)redhat.com)
- Added new "vm -[xd]" options to be used in conjunction with
"vm -[mv]", which override the current default output format
with hexadecimal or decimal format for just the command instance.
Without the patch, it would require changing the default output
format with "hex" or "dec" prior to executing "vm -[mv]". The
new flags may also be used with "foreach vm -[mv]".
(anderson(a)redhat.com)
- Fix for the s390x "vm -p" and "vtop -u <user-address>" commands
if the page containing the relevant PTE is not mapped. Without
the patch, the commands fail with the error message "vm: read error:
kernel virtual address: 0 type: entry" or "vtop: read error: kernel
virtual address: 0 type: entry"
(holzheu(a)linux.vnet.ibm.com)
- Fix for the s390x "vm -p" command and "vtop -u <user-address>"
commands to properly translate pages that are swapped out into their
swap file and offset. Without the patch, the swap file and offset
would not be displayed.
(holzheu(a)linux.vnet.ibm.com)
- Added new "list -[xd]" options to be used in conjunction with
"list -s", which override the current default output format
with hexadecimal or decimal format for just the command instance.
Without the patch, it would require changing the default output
format with "hex" or "dec" prior to executing "list -s".
(anderson(a)redhat.com)
- Added new "net -[xd]" options to be used in conjunction with
"net -S", which override the current default output format
with hexadecimal or decimal format for just the command instance.
Without the patch, it would require changing the default output
format with "hex" or "dec" prior to executing "net -S". The new
flags may also be used with "foreach net -S".
(anderson(a)redhat.com)
- Added new "mach -[xd]" options to be used in conjunction with
"mach -c", which override the current default output format
with hexadecimal or decimal format for just the command instance.
Without the patch, it would require changing the default output
format with "hex" or "dec" prior to executing "mach -c".
(anderson(a)redhat.com)
- If the value read from the cpu online, present, or possible masks
contains a cpu bit value that is outside the architecture's maximum
NR_CPUS value, print a warning message during invocation. Without
the patch, a corrupt vmcore containing a bogus mask value could
quietly corrupt heap memory.
(per.fransson.ml(a)gmail.com)
- Add support to for reading dumpfiles compressed by LZO using
makedumpfile version 1.4.4 or later. This feature is disabled by
default. To enable this feature, build the crash utility in the
following manner:
(1) Install the LZO libraries by using the host system's package
manager or by directly downloading libraries from author's
website. The packages required are:
- lzo
- lzo-minilzo
- lzo-devel
The author's website is: http://www.oberhumer.com/opensource/lzo
(2) Create a CFLAGS.extra file and an LDFLAGS.extra file in top-level
crash sources directory:
- enter -DLZO in the CFLAGS.extra file
- enter -llzo2 in the LDFLAGS.extra file.
(3) Build crash with "make" as always.
(d.hatayama(a)jp.fujitsu.com)
- Fix for the included "trace" extension module. Without the patch,
if the module initialization sequence fails, a double-free in the
module may lead to a subsequent malloc() segmentation violation
in the crash session.
(per.fransson.ml(a)gmail.com)
- Incorporated the "ipcs" extension module written by Qiao Nuohan
as a built-in command. The command displays the kernel's usage
of the System V shared memory, semaphore and message queue IPC
facilities. It differs from the original extension module by
fixing a failure scenario if the current task is exiting, and
adds a "-n pid|task" option, which displays the IPCS facilities
with respect to the namespace of a given pid or task.
(qiaonuohan(a)cn.fujitsu.com, anderson(a)redhat.com)
- Fix for a gdb-7.3.1 regression that causes the line number capability
to fail with certain ranges of x86 base kernel text addresses.
Without the patch, the "dis -l <symbol>" or "sym <symbol>"
commands would fail to show line number information for certain
ranges of base kernel text addresses.
(anderson(a)redhat.com)
- Added a new "printm" command to the embedded gdb module. It
is currently only used by the "pstruct" extension module, but
can be used to dump the type, size, offset, bitpos and bitsize
values of an expression.
(qiaonuohan(a)cn.fujitsu.com)
- Added a new "runq -t" option that displays the timestamp information
of each cpu's runqueue, which consists of either the rq.clock, the
rq.most_recent_timestamp or rq.timestamp_last_tick value, whichever
applies. Following each cpu timestamp is the last_run or timestamp
value of the active task on that cpu, whichever applies, along with
the task identification.
(weijg.fnst(a)cn.fujitsu.com, anderson(a)redhat.com)
- Fix for an initialization-time warning when running on a live system
with the most recent version of the modprobe command, which no longer
supports the -l and --type options. The modprobe is used to detect
whether the crash.ko memory driver is part of the distribution.
Without the patch, a warning message is issued that indicates
"/sbin/modprobe: invalid option -- 'l'". If the driver is built into
the kernel, the message is harmless. If the driver is not built into
kernel, then the crash.ko (/dev/crash) driver would not be selected
as the live memory source.
(anderson(a)redhat.com)
12 years, 6 months
