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Seiji Aguchi 755d4fe465 efi_pstore: Add a sequence counter to a variable name
[Issue]

Currently, a variable name, which identifies each entry, consists of type, id and ctime.
But if multiple events happens in a short time, a second/third event may fail to log because
efi_pstore can't distinguish each event with current variable name.

[Solution]

A reasonable way to identify all events precisely is introducing a sequence counter to
the variable name.

The sequence counter has already supported in a pstore layer with "oopscount".
So, this patch adds it to a variable name.
Also, it is passed to read/erase callbacks of platform drivers in accordance with
the modification of the variable name.

  <before applying this patch>
 a variable name of first event: dump-type0-1-12345678
 a variable name of second event: dump-type0-1-12345678

  type:0
  id:1
  ctime:12345678

 If multiple events happen in a short time, efi_pstore can't distinguish them because
 variable names are same among them.

  <after applying this patch>

 it can be distinguishable by adding a sequence counter as follows.

 a variable name of first event: dump-type0-1-1-12345678
 a variable name of Second event: dump-type0-1-2-12345678

  type:0
  id:1
  sequence counter: 1(first event), 2(second event)
  ctime:12345678

In case of a write callback executed in pstore_console_write(), "0" is added to
an argument of the write callback because it just logs all kernel messages and
doesn't need to care about multiple events.

Signed-off-by: Seiji Aguchi <seiji.aguchi@hds.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Mike Waychison <mikew@google.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
2012-11-26 16:07:44 -08:00
Seiji Aguchi a9efd39cd5 efi_pstore: Add ctime to argument of erase callback
[Issue]

Currently, a variable name, which is used to identify each log entry, consists of type,
id and ctime. But an erase callback does not use ctime.

If efi_pstore supported just one log, type and id were enough.
However, in case of supporting multiple logs, it doesn't work because
it can't distinguish each entry without ctime at erasing time.

 <Example>

 As you can see below, efi_pstore can't differentiate first event from second one without ctime.

 a variable name of first event: dump-type0-1-12345678
 a variable name of second event: dump-type0-1-23456789

  type:0
  id:1
  ctime:12345678, 23456789

[Solution]

This patch adds ctime to an argument of an erase callback.

It works across reboots because ctime of pstore means the date that the record was originally stored.
To do this, efi_pstore saves the ctime to variable name at writing time and passes it to pstore
at reading time.

Signed-off-by: Seiji Aguchi <seiji.aguchi@hds.com>
Acked-by: Mike Waychison <mikew@google.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
2012-11-26 16:02:12 -08:00
Colin Ian King 70a6f46d7b pstore: Fix NULL pointer dereference in console writes
Passing a NULL id causes a NULL pointer deference in writers such as
erst_writer and efi_pstore_write because they expect to update this id.
Pass a dummy id instead.

This avoids a cascade of oopses caused when the initial
pstore_console_write passes a null which in turn causes writes to the
console causing further oopses in subsequent pstore_console_write calls.

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: stable@vger.kernel.org
Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org>
2012-11-14 18:30:21 -08:00
Chuansheng Liu 80c9d03c22 pstore: Avoid recursive spinlocks in the oops_in_progress case
Like 8250 driver, when pstore is registered as a console,
to avoid recursive spinlocks when panic happening, change the
spin_lock_irqsave to spin_trylock_irqsave when oops_in_progress
is true.

Signed-off-by: liu chuansheng <chuansheng.liu@intel.com>
Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org>
2012-09-20 17:04:50 -07:00
Anton Vorontsov 65f8c95e46 pstore/ftrace: Convert to its own enable/disable debugfs knob
With this patch we no longer reuse function tracer infrastructure, now
we register our own tracer back-end via a debugfs knob.

It's a bit more code, but that is the only downside. On the bright side we
have:

- Ability to make persistent_ram module removable (when needed, we can
  move ftrace_ops struct into a module). Note that persistent_ram is still
  not removable for other reasons, but with this patch it's just one
  thing less to worry about;

- Pstore part is more isolated from the generic function tracer. We tried
  it already by registering our own tracer in available_tracers, but that
  way we're loosing ability to see the traces while we record them to
  pstore. This solution is somewhere in the middle: we only register
  "internal ftracer" back-end, but not the "front-end";

- When there is only pstore tracing enabled, the kernel will only write
  to the pstore buffer, omitting function tracer buffer (which, of course,
  still can be enabled via 'echo function > current_tracer').

Suggested-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org>
2012-09-06 22:16:58 -07:00
Jovi Zhang b4a871bce6 pstore/ram: Add missing platform_device_unregister
We need to unregister platform device when module exit, this commit fixes
the issue.

Signed-off-by: Jovi Zhang <bookjovi@gmail.com>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org>
2012-08-31 15:29:42 -07:00
Anton Vorontsov 242030365e pstore/ram: Mark ramoops_pstore_write_buf() as notrace
write_buf() should be marked as notrace, otherwise it is prone to
recursion.

Though, yet the issue is never triggered in real life, because we run
inside the function tracer, where ftrace does its own recurse protection.

But it's still no good, plus soon we might switch to our own tracer ops,
and then the issue will be fatal. So, let's fix it.

Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org>
2012-08-04 16:16:47 -07:00
Randy Dunlap 0427193b69 pstore/ram: Fix printk format warning
Fix printk format warning (on i386) in pstore:

fs/pstore/ram.c:409:3: warning: format '%lu' expects type 'long unsigned int', but argument 2 has type 'size_t'

Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org>
2012-08-04 16:16:45 -07:00
Anton Vorontsov a384f64117 pstore/ram: Fix possible NULL dereference
We can dereference 'cxt->cprz' if console and dump logging are disabled
(which is unlikely, but still possible to do). This patch fixes the issue
by changing the code so that we don't dereference przs at all, we can
just calculate bufsize from console_size and record_size values.

Plus, while at it, the patch improves the buffer size calculation.

After Kay's printk rework, we know the optimal buffer size for console
logging -- it is LOG_LINE_MAX (defined privately in printk.c). Previously,
if only console logging was enabled, we would allocate unnecessary large
buffer in pstore, while we only need LOG_LINE_MAX. (Pstore console logging
is still capable of handling buffers > LOG_LINE_MAX, it will just do
multiple calls to psinfo->write).

Note that I don't export the constant, since we will do even a better
thing soon: we will switch console logging to a new write_buf API, which
will eliminate the need for the additional buffer; and so we won't need
the constant.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org>
Acked-by: Kees Cook <keescook@chromium.org>
2012-08-04 16:16:43 -07:00
Anton Vorontsov cbe7cbf5a6 pstore/ram: Make tracing log versioned
Decoding the binary trace w/ a different kernel might be troublesome
since we convert addresses to symbols. For kernels with minimal changes,
the mappings would probably match, but it's not guaranteed at all.
(But still we could convert the addresses by hand, since we do print
raw addresses.)

If we use modules, the symbols could be loaded at different addresses
from the previously booted kernel, and so this would also fail, but
there's nothing we can do about it.

Also, the binary data format that pstore/ram is using in its ringbuffer
may change between the kernels, so here we too must ensure that we're
running the same kernel.

So, there are two questions really:

1. How to compute the unique kernel tag;
2. Where to store it.

In this patch we're using LINUX_VERSION_CODE, just as hibernation
(suspend-to-disk) does. This way we are protecting from the kernel
version mismatch, making sure that we're running the same kernel
version and patch level. We could use CRC of a symbol table (as
suggested by Tony Luck), but for now let's not be that strict.

And as for storing, we are using a small trick here. Instead of
allocating a dedicated buffer for the tag (i.e. another prz), or
hacking ram_core routines to "reserve" some control data in the
buffer, we are just encoding the tag into the buffer signature
(and XOR'ing it with the actual signature value, so that buffers
not needing a tag can just pass zero, which will result into the
plain old PRZ signature).

Suggested-by: Steven Rostedt <rostedt@goodmis.org>
Suggested-by: Tony Luck <tony.luck@intel.com>
Suggested-by: Colin Cross <ccross@android.com>
Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-07-17 16:48:09 -07:00
Anton Vorontsov 67a101f573 pstore: Headers should include all stuff they use
Headers should really include all the needed prototypes, types, defines
etc. to be self-contained. This is a long-standing issue, but apparently
the new tracing code unearthed it (SMP=n is also a prerequisite):

In file included from fs/pstore/internal.h:4:0,
                 from fs/pstore/ftrace.c:21:
include/linux/pstore.h:43:15: error: field ‘read_mutex’ has incomplete type

While at it, I also added the following:

linux/types.h -> size_t, phys_addr_t, uXX and friends
linux/spinlock.h -> spinlock_t
linux/errno.h -> Exxxx
linux/time.h -> struct timespec (struct passed by value)
struct module and rs_control forward declaration (passed via pointers).

Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-07-17 12:15:30 -07:00
Anton Vorontsov a694d1b591 pstore/ram: Add ftrace messages handling
The ftrace log size is configurable via ramoops.ftrace_size
module option, and the log itself is available via
<pstore-mount>/ftrace-ramoops file.

Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-07-17 10:14:17 -07:00
Anton Vorontsov c2b7113261 pstore/ram: Convert to write_buf callback
Don't use pstore.buf directly, instead convert the code to write_buf callback
which passes a pointer to a buffer as an argument.

Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-07-17 10:07:09 -07:00
Anton Vorontsov 060287b8c4 pstore: Add persistent function tracing
With this support kernel can save function call chain log into a
persistent ram buffer that can be decoded and dumped after reboot
through pstore filesystem. It can be used to determine what function
was last called before a reset or panic.

We store the log in a binary format and then decode it at read time.

p.s.
Mostly the code comes from trace_persistent.c driver found in the
Android git tree, written by Colin Cross <ccross@android.com>
(according to sign-off history). I reworked the driver a little bit,
and ported it to pstore.

Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-07-17 10:05:52 -07:00
Anton Vorontsov 897dba0274 pstore: Introduce write_buf backend callback
For function tracing we need to stop using pstore.buf directly, since
in a tracing callback we can't use spinlocks, and thus we can't safely
use the global buffer.

With write_buf callback, backends no longer need to access pstore.buf
directly, and thus we can pass any buffers (e.g. allocated on stack).

Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-07-17 09:51:38 -07:00
Anton Vorontsov c1743cbc8d pstore/ram_core: Get rid of prz->ecc enable/disable flag
Nowadays we can use prz->ecc_size as a flag, no need for the special
member in the prz struct.

Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-07-17 09:46:52 -07:00
Anton Vorontsov 5ca5d4e61d pstore/ram: Make ECC size configurable
This is now pretty straightforward: instead of using bool, just pass
an integer. For backwards compatibility ramoops.ecc=1 means 16 bytes
ECC (using 1 byte for ECC isn't much of use anyway).

Suggested-by: Arve Hjønnevåg <arve@android.com>
Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-07-17 09:46:52 -07:00
Anton Vorontsov 4a53ffae6a pstore/ram_core: Get rid of prz->ecc_symsize and prz->ecc_poly
The struct members were never used anywhere outside of
persistent_ram_init_ecc(), so there's actually no need for them
to be in the struct.

If we ever want to make polynomial or symbol size configurable,
it would make more sense to just pass initialized rs_decoder
to the persistent_ram init functions.

Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-07-17 09:46:52 -07:00
Greg Kroah-Hartman bcc66c0b88 Merge 3.5-rc4 into staging-next
This picks up the staging changes made in 3.5-rc4 so that everyone can sync up
properly.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-06-25 09:31:00 -07:00
Anton Vorontsov 1e6a9e5625 pstore/ram_core: Better ECC size checking
- Instead of exploiting unsigned overflows (which doesn't work for all
  sizes), use straightforward checking for ECC total size not exceeding
  initial buffer size;

- Printing overflowed buffer_size is not informative. Instead, print
  ecc_size and buffer_size;

- No need for buffer_size argument in persistent_ram_init_ecc(),
  we can address prz->buffer_size directly.

Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-06-20 16:15:22 -07:00
Anton Vorontsov beeb94321a pstore/ram_core: Proper checking for post_init errors (e.g. improper ECC size)
We will implement variable-sized ECC buffers soon, so post_init routine
might fail much more likely, so we'd better check for its errors.

To make error handling simple, modify persistent_ram_free() to it be safe
at all times.

Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-06-20 16:15:22 -07:00
Anton Vorontsov 90b58d9690 pstore/ram: Fix error handling during przs allocation
persistent_ram_new() returns ERR_PTR() value on errors, so during
freeing of the przs we should check for both NULL and IS_ERR() entries,
otherwise bad things will happen.

Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-06-20 16:15:22 -07:00
Anton Vorontsov 924d37118f pstore/ram: Probe as early as possible
Registering the platform driver before module_init allows us to log oopses
that happen during device probing.

This requires changing module_init to postcore_initcall, and switching
from platform_driver_probe to platform_driver_register because the
platform device is not registered when the platform driver is registered;
and because we use driver_register, now can't use create_bundle() (since
it will try to register the same driver once again), so we have to switch
to platform_device_register_data().

Also, some __init -> __devinit changes were needed.

Overall, the registration logic is now much clearer, since we have only
one driver registration point, and just an optional dummy device, which
is created from the module parameters.

Suggested-by: Colin Cross <ccross@android.com>
Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-06-20 16:15:22 -07:00
Linus Torvalds bc259adc9b staging tree fixes for 3.5-rc4
Here are a number of small fixes for the drivers/staging tree, as well as iio
 and pstore drivers (which came from the staging tree in the 3.5-rc1 merge).
 All of these are tiny, but resolve issues that people have been reporting.
 
 There's also a documentation update to reflect what the iio drivers really are
 doing, which is good to get straightened out.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'staging-3.5-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging

Pull staging tree fixes from Greg Kroah-Hartman:
 "Here are a number of small fixes for the drivers/staging tree, as well
  as iio and pstore drivers (which came from the staging tree in the
  3.5-rc1 merge).  All of these are tiny, but resolve issues that people
  have been reporting.

  There's also a documentation update to reflect what the iio drivers
  really are doing, which is good to get straightened out.

  Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>"

* tag 'staging-3.5-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging:
  staging: r8712u: Add new USB IDs
  staging: gdm72xx: Release netlink socket properly
  iio: drop wrong reference from Kconfig
  pstore/inode: Make pstore_fill_super() static
  pstore/ram: Should zap persistent zone on unlink
  pstore/ram_core: Factor persistent_ram_zap() out of post_init()
  pstore/ram_core: Do not reset restored zone's position and size
  pstore/ram: Should update old dmesg buffer before reading
  staging:iio:ad7298: Fix linker error due to missing IIO kfifo buffer
  Revert "staging: usbip: bugfix for stack corruption on 64-bit architectures"
  staging: usbip: bugfix for stack corruption on 64-bit architectures
  staging/comedi: fix build for USB not enabled
  staging: omapdrm: fix crash when freeing bad fb
  staging:iio:ad7606: Re-add missing scale attribute
  iio: Fix potential use after free
  staging:iio: remove num_interrupt_lines from documentation
  iio: documentation: Add out_altvoltage and friends
2012-06-20 15:15:03 -07:00
Kay Sievers e2ae715d66 kmsg - kmsg_dump() use iterator to receive log buffer content
Provide an iterator to receive the log buffer content, and convert all
kmsg_dump() users to it.

The structured data in the kmsg buffer now contains binary data, which
should no longer be copied verbatim to the kmsg_dump() users.

The iterator should provide reliable access to the buffer data, and also
supports proper log line-aware chunking of data while iterating.

Signed-off-by: Kay Sievers <kay@vrfy.org>
Tested-by: Tony Luck <tony.luck@intel.com>
Reported-by: Anton Vorontsov <anton.vorontsov@linaro.org>
Tested-by: Anton Vorontsov <anton.vorontsov@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-06-15 14:53:59 -07:00
Anton Vorontsov 521f7288a8 pstore/platform: Disable automatic updates by default
Having automatic updates seems pointless for production system, and
even dangerous and thus counter-productive:

1. If we can mount pstore, or read files, we can as well read
   /proc/kmsg. So, there's little point in duplicating the
   functionality and present the same information but via another
   userland ABI;

2. Expecting the kernel to behave sanely after oops/panic is naive.
   It might work, but you'd rather not try it. Screwed up kernel
   can do rather bad things, like recursive faults[1]; and pstore
   rather provoking bad things to happen. It uses:

   1. Timers (assumes sane interrupts state);
   2. Workqueues and mutexes (assumes scheduler in a sane state);
   3. kzalloc (a working slab allocator);

   That's too much for a dead kernel, so the debugging facility
   itself might just make debugging harder, which is not what
   we want.

Maybe for non-oops message types it would make sense to re-enable
automatic updates, but so far I don't see any use case for this.
Even for tracing, it has its own run-time/normal ABI, so we're
only interested in pstore upon next boot, to retrieve what has
gone wrong with HW or SW.

So, let's disable the updates by default.

[1]
BUG: unable to handle kernel paging request at fffffffffffffff8
IP: [<ffffffff8104801b>] kthread_data+0xb/0x20
[...]
Process kworker/0:1 (pid: 14, threadinfo ffff8800072c0000, task ffff88000725b100)
[...
Call Trace:
 [<ffffffff81043710>] wq_worker_sleeping+0x10/0xa0
 [<ffffffff813687a8>] __schedule+0x568/0x7d0
 [<ffffffff8106c24d>] ? trace_hardirqs_on+0xd/0x10
 [<ffffffff81087e22>] ? call_rcu_sched+0x12/0x20
 [<ffffffff8102b596>] ? release_task+0x156/0x2d0
 [<ffffffff8102b45e>] ? release_task+0x1e/0x2d0
 [<ffffffff8106c24d>] ? trace_hardirqs_on+0xd/0x10
 [<ffffffff81368ac4>] schedule+0x24/0x70
 [<ffffffff8102cba8>] do_exit+0x1f8/0x370
 [<ffffffff810051e7>] oops_end+0x77/0xb0
 [<ffffffff8135c301>] no_context+0x1a6/0x1b5
 [<ffffffff8135c4de>] __bad_area_nosemaphore+0x1ce/0x1ed
 [<ffffffff81053156>] ? ttwu_queue+0xc6/0xe0
 [<ffffffff8135c50b>] bad_area_nosemaphore+0xe/0x10
 [<ffffffff8101fa47>] do_page_fault+0x2c7/0x450
 [<ffffffff8106e34b>] ? __lock_release+0x6b/0xe0
 [<ffffffff8106bf21>] ? mark_held_locks+0x61/0x140
 [<ffffffff810502fe>] ? __wake_up+0x4e/0x70
 [<ffffffff81185f7d>] ? trace_hardirqs_off_thunk+0x3a/0x3c
 [<ffffffff81158970>] ? pstore_register+0x120/0x120
 [<ffffffff8136a37f>] page_fault+0x1f/0x30
 [<ffffffff81158970>] ? pstore_register+0x120/0x120
 [<ffffffff81185ab8>] ? memcpy+0x68/0x110
 [<ffffffff8115875a>] ? pstore_get_records+0x3a/0x130
 [<ffffffff811590f4>] ? persistent_ram_copy_old+0x64/0x90
 [<ffffffff81158bf4>] ramoops_pstore_read+0x84/0x130
 [<ffffffff81158799>] pstore_get_records+0x79/0x130
 [<ffffffff81042536>] ? process_one_work+0x116/0x450
 [<ffffffff81158970>] ? pstore_register+0x120/0x120
 [<ffffffff8115897e>] pstore_dowork+0xe/0x10
 [<ffffffff81042594>] process_one_work+0x174/0x450
 [<ffffffff81042536>] ? process_one_work+0x116/0x450
 [<ffffffff81042e13>] worker_thread+0x123/0x2d0
 [<ffffffff81042cf0>] ? manage_workers.isra.28+0x120/0x120
 [<ffffffff81047d8e>] kthread+0x8e/0xa0
 [<ffffffff8136ba74>] kernel_thread_helper+0x4/0x10
 [<ffffffff8136a199>] ? retint_restore_args+0xe/0xe
 [<ffffffff81047d00>] ? __init_kthread_worker+0x70/0x70
 [<ffffffff8136ba70>] ? gs_change+0xb/0xb
Code: be e2 00 00 00 48 c7 c7 d1 2a 4e 81 e8 bf fb fd ff 48 8b 5d f0 4c 8b 65 f8 c9 c3 0f 1f 44 00 00 48 8b 87 08 02 00 00 55 48 89 e5 <48> 8b 40 f8 5d c3 66 66 66 66 66 66 2e 0f 1f 84 00 00 00 00 00
RIP  [<ffffffff8104801b>] kthread_data+0xb/0x20
 RSP <ffff8800072c1888>
CR2: fffffffffffffff8
---[ end trace 996a332dc399111d ]---
Fixing recursive fault but reboot is needed!

Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-06-13 16:59:37 -07:00
Anton Vorontsov a3f5f075c2 pstore/platform: Make automatic updates interval configurable
There is no behavioural change, the default value is still 60 seconds.

Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-06-13 16:59:37 -07:00
Anton Vorontsov b8587daa75 pstore/ram_core: Remove now unused code
The code tried to maintain the global list of persistent ram zones,
which isn't a great idea overall, plus since Android's ram_console
is no longer there, we can remove some unused functions.

Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org>
Acked-by: Kees Cook <keescook@chromium.org>
Acked-by: Colin Cross <ccross@android.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-06-13 16:59:37 -07:00
Anton Vorontsov 602b5be4f1 pstore/ram_core: Silence some printks
Since we use multiple regions, the messages are somewhat annoying.
We do print total mapped memory already, so no need to print the
information for each region in the library routines.

Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org>
Acked-by: Kees Cook <keescook@chromium.org>
Acked-by: Colin Cross <ccross@android.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-06-13 16:59:28 -07:00
Anton Vorontsov b5d38e9bf1 pstore/ram: Add console messages handling
The console log size is configurable via ramoops.console_size
module option, and the log itself is available via
<pstore-mount>/console-ramoops file.

Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-06-13 16:59:28 -07:00
Anton Vorontsov 755d66b48f pstore/ram: Factor ramoops_get_next_prz() out of ramoops_pstore_read()
This will help make code clearer when we'll add support for other
message types.

The patch also changes return value from -EINVAL to 0 in case of
end-of-records. The exact value doesn't matter for pstore (it should
be just <= 0), but 0 feels more correct.

Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-06-13 16:59:28 -07:00
Anton Vorontsov f4c5d2423c pstore/ram: Factor dmesg przs initialization out of probe()
This will help make code clearer when we'll add support for other
message types.

This also makes probe() much shorter and understandable, plus
makes mem/record size checking a bit easier.

Implementation detail: we now use a paddr pointer, this will
be used for allocating persistent ram zones for other message
types.

Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-06-13 16:59:28 -07:00
Anton Vorontsov cac2eb7b58 pstore/ram: Give proper names to dump-related variables
We're about to add support for other message types, so let's rename
some variables to not be confused later.

Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-06-13 16:59:28 -07:00
Anton Vorontsov f29e5956ae pstore: Add console log messages support
Pstore doesn't support logging kernel messages in run-time, it only
dumps dmesg when kernel oopses/panics. This makes pstore useless for
debugging hangs caused by HW issues or improper use of HW (e.g.
weird device inserted -> driver tried to write a reserved bits ->
SoC hanged. In that case we don't get any messages in the pstore.

Therefore, let's add a runtime logging support: PSTORE_TYPE_CONSOLE.

Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org>
Acked-by: Kees Cook <keescook@chromium.org>
Acked-by: Colin Cross <ccross@android.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-06-13 16:59:27 -07:00
Anton Vorontsov 364ed2f465 pstore/inode: Make pstore_fill_super() static
There's no reason to extern it. The patch fixes the annoying sparse
warning:

CHECK   fs/pstore/inode.c
fs/pstore/inode.c:264:5: warning: symbol 'pstore_fill_super' was not
declared. Should it be static?

Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-06-13 16:52:40 -07:00
Anton Vorontsov 93cce04968 pstore/ram: Should zap persistent zone on unlink
Otherwise, unlinked file will reappear on the next boot.

Reported-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-06-13 16:52:40 -07:00
Anton Vorontsov fce3979304 pstore/ram_core: Factor persistent_ram_zap() out of post_init()
A handy function that we will use outside of ram_core soon. But
so far just factor it out and start using it in post_init().

Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-06-13 16:52:40 -07:00
Anton Vorontsov 25b63da647 pstore/ram_core: Do not reset restored zone's position and size
Otherwise, the files will survive just one reboot, and on a subsequent
boot they will disappear.

Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-06-13 16:52:39 -07:00
Anton Vorontsov 201e4aca5a pstore/ram: Should update old dmesg buffer before reading
Without the update, we'll only see the new dmesg buffer after the
reboot, but previously we could see it right away. Making an oops
visible in pstore filesystem before reboot is a somewhat dubious
feature, but removing it wasn't an intentional change, so let's
restore it.

For this we have to make persistent_ram_save_old() safe for calling
multiple times, and also extern it.

Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-06-13 16:52:39 -07:00
Linus Torvalds 90324cc1b1 avoid iput() from flusher thread
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Merge tag 'writeback' of git://git.kernel.org/pub/scm/linux/kernel/git/wfg/linux

Pull writeback tree from Wu Fengguang:
 "Mainly from Jan Kara to avoid iput() in the flusher threads."

* tag 'writeback' of git://git.kernel.org/pub/scm/linux/kernel/git/wfg/linux:
  writeback: Avoid iput() from flusher thread
  vfs: Rename end_writeback() to clear_inode()
  vfs: Move waiting for inode writeback from end_writeback() to evict_inode()
  writeback: Refactor writeback_single_inode()
  writeback: Remove wb->list_lock from writeback_single_inode()
  writeback: Separate inode requeueing after writeback
  writeback: Move I_DIRTY_PAGES handling
  writeback: Move requeueing when I_SYNC set to writeback_sb_inodes()
  writeback: Move clearing of I_SYNC into inode_sync_complete()
  writeback: initialize global_dirty_limit
  fs: remove 8 bytes of padding from struct writeback_control on 64 bit builds
  mm: page-writeback.c: local functions should not be exposed globally
2012-05-28 09:54:45 -07:00
Anton Vorontsov 39eb7e9791 pstore/ram: Add ECC support
This is now straightforward: just introduce a module parameter and pass
the needed value to persistent_ram_new().

Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org>
Acked-by: Marco Stornelli <marco.stornelli@gmail.com>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-05-17 08:51:59 -07:00
Anton Vorontsov 896fc1f0c4 pstore/ram: Switch to persistent_ram routines
The patch switches pstore RAM backend to use persistent_ram routines,
one step closer to the ECC support.

Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org>
Acked-by: Marco Stornelli <marco.stornelli@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-05-17 08:51:41 -07:00
Anton Vorontsov cddb8751c8 staging: android: persistent_ram: Move to fs/pstore/ram_core.c
This is a first step for adding ECC support for pstore RAM backend: we
will use the persistent_ram routines, kindly provided by Google.

Basically, persistent_ram is a set of helper routines to deal with the
[optionally] ECC-protected persistent ram regions.

A bit of Makefile, Kconfig and header files adjustments were needed
because of the move.

Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-05-17 08:50:00 -07:00
Anton Vorontsov 1894a253db ramoops: Move to fs/pstore/ram.c
Since ramoops was converted to pstore, it has nothing to do with character
devices nowadays. Instead, today it is just a RAM backend for pstore.

The patch just moves things around. There are a few changes were needed
because of the move:

1. Kconfig and Makefiles fixups, of course.

2. In pstore/ram.c we have to play a bit with MODULE_PARAM_PREFIX, this
   is needed to keep user experience the same as with ramoops driver
   (i.e. so that ramoops.foo kernel command line arguments would still
   work).

Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org>
Acked-by: Marco Stornelli <marco.stornelli@gmail.com>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-05-16 08:06:37 -07:00
Jan Kara dbd5768f87 vfs: Rename end_writeback() to clear_inode()
After we moved inode_sync_wait() from end_writeback() it doesn't make sense
to call the function end_writeback() anymore. Rename it to clear_inode()
which well says what the function really does - set I_CLEAR flag.

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
2012-05-06 13:43:41 +08:00
Linus Torvalds 5d32c88f0b Merge branch 'akpm' (Andrew's patch-bomb)
Merge batch of fixes from Andrew Morton:
 "The simple_open() cleanup was held back while I wanted for laggards to
  merge things.

  I still need to send a few checkpoint/restore patches.  I've been
  wobbly about merging them because I'm wobbly about the overall
  prospects for success of the project.  But after speaking with Pavel
  at the LSF conference, it sounds like they're further toward
  completion than I feared - apparently davem is at the "has stopped
  complaining" stage regarding the net changes.  So I need to go back
  and re-review those patchs and their (lengthy) discussion."

* emailed from Andrew Morton <akpm@linux-foundation.org>: (16 patches)
  memcg swap: use mem_cgroup_uncharge_swap fix
  backlight: add driver for DA9052/53 PMIC v1
  C6X: use set_current_blocked() and block_sigmask()
  MAINTAINERS: add entry for sparse checker
  MAINTAINERS: fix REMOTEPROC F: typo
  alpha: use set_current_blocked() and block_sigmask()
  simple_open: automatically convert to simple_open()
  scripts/coccinelle/api/simple_open.cocci: semantic patch for simple_open()
  libfs: add simple_open()
  hugetlbfs: remove unregister_filesystem() when initializing module
  drivers/rtc/rtc-88pm860x.c: fix rtc irq enable callback
  fs/xattr.c:setxattr(): improve handling of allocation failures
  fs/xattr.c:listxattr(): fall back to vmalloc() if kmalloc() failed
  fs/xattr.c: suppress page allocation failure warnings from sys_listxattr()
  sysrq: use SEND_SIG_FORCED instead of force_sig()
  proc: fix mount -t proc -o AAA
2012-04-05 15:30:34 -07:00
Stephen Boyd 234e340582 simple_open: automatically convert to simple_open()
Many users of debugfs copy the implementation of default_open() when
they want to support a custom read/write function op.  This leads to a
proliferation of the default_open() implementation across the entire
tree.

Now that the common implementation has been consolidated into libfs we
can replace all the users of this function with simple_open().

This replacement was done with the following semantic patch:

<smpl>
@ open @
identifier open_f != simple_open;
identifier i, f;
@@
-int open_f(struct inode *i, struct file *f)
-{
(
-if (i->i_private)
-f->private_data = i->i_private;
|
-f->private_data = i->i_private;
)
-return 0;
-}

@ has_open depends on open @
identifier fops;
identifier open.open_f;
@@
struct file_operations fops = {
...
-.open = open_f,
+.open = simple_open,
...
};
</smpl>

[akpm@linux-foundation.org: checkpatch fixes]
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Julia Lawall <Julia.Lawall@lip6.fr>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-04-05 15:25:50 -07:00
Al Viro 22a71c3055 pstore: trim pstore_get_inode()
move mode-dependent parts to callers, kill unused arguments

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-03-31 16:03:15 -04:00
Linus Torvalds 6e55f8ed81 One pstore patch
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Merge tag 'pstore-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux

Pull one pstore patch from Tony Luck

* tag 'pstore-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux:
  pstore: Introduce get_reason_str() to pstore
2012-03-23 09:24:07 -07:00
Al Viro 318ceed088 tidy up after d_make_root() conversion
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-03-20 21:29:37 -04:00