Commit Graph

193 Commits

Author SHA1 Message Date
Sven Schmidt
d21b5ff12d fs/pstore: fs/squashfs: change usage of LZ4 to work with new LZ4 version
Update fs/pstore and fs/squashfs to use the updated functions from the
new LZ4 module.

Link: http://lkml.kernel.org/r/1486321748-19085-5-git-send-email-4sschmid@informatik.uni-hamburg.de
Signed-off-by: Sven Schmidt <4sschmid@informatik.uni-hamburg.de>
Cc: Bongkyu Kim <bongkyu.kim@lge.com>
Cc: Rui Salvaterra <rsalvaterra@gmail.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: David S. Miller <davem@davemloft.net>
Cc: Anton Vorontsov <anton@enomsg.org>
Cc: Colin Cross <ccross@android.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Tony Luck <tony.luck@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-02-24 17:46:57 -08:00
Kees Cook
46418413ed pstore: Check for prz allocation in walker
Instead of needing additional checks in callers for unallocated przs,
perform the check in the walker, which gives us a more universal way to
handle the situation.

Signed-off-by: Kees Cook <keescook@chromium.org>
2017-02-13 10:25:52 -08:00
Kees Cook
76d5692a58 pstore: Correctly initialize spinlock and flags
The ram backend wasn't always initializing its spinlock correctly. Since
it was coming from kzalloc memory, though, it was harmless on
architectures that initialize unlocked spinlocks to 0 (at least x86 and
ARM). This also fixes a possibly ignored flag setting too.

When running under CONFIG_DEBUG_SPINLOCK, the following Oops was visible:

[    0.760836] persistent_ram: found existing buffer, size 29988, start 29988
[    0.765112] persistent_ram: found existing buffer, size 30105, start 30105
[    0.769435] persistent_ram: found existing buffer, size 118542, start 118542
[    0.785960] persistent_ram: found existing buffer, size 0, start 0
[    0.786098] persistent_ram: found existing buffer, size 0, start 0
[    0.786131] pstore: using zlib compression
[    0.790716] BUG: spinlock bad magic on CPU#0, swapper/0/1
[    0.790729]  lock: 0xffffffc0d1ca9bb0, .magic: 00000000, .owner: <none>/-1, .owner_cpu: 0
[    0.790742] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.10.0-rc2+ #913
[    0.790747] Hardware name: Google Kevin (DT)
[    0.790750] Call trace:
[    0.790768] [<ffffff900808ae88>] dump_backtrace+0x0/0x2bc
[    0.790780] [<ffffff900808b164>] show_stack+0x20/0x28
[    0.790794] [<ffffff9008460ee0>] dump_stack+0xa4/0xcc
[    0.790809] [<ffffff9008113cfc>] spin_dump+0xe0/0xf0
[    0.790821] [<ffffff9008113d3c>] spin_bug+0x30/0x3c
[    0.790834] [<ffffff9008113e28>] do_raw_spin_lock+0x50/0x1b8
[    0.790846] [<ffffff9008a2d2ec>] _raw_spin_lock_irqsave+0x54/0x6c
[    0.790862] [<ffffff90083ac3b4>] buffer_size_add+0x48/0xcc
[    0.790875] [<ffffff90083acb34>] persistent_ram_write+0x60/0x11c
[    0.790888] [<ffffff90083aab1c>] ramoops_pstore_write_buf+0xd4/0x2a4
[    0.790900] [<ffffff90083a9d3c>] pstore_console_write+0xf0/0x134
[    0.790912] [<ffffff900811c304>] console_unlock+0x48c/0x5e8
[    0.790923] [<ffffff900811da18>] register_console+0x3b0/0x4d4
[    0.790935] [<ffffff90083aa7d0>] pstore_register+0x1a8/0x234
[    0.790947] [<ffffff90083ac250>] ramoops_probe+0x6b8/0x7d4
[    0.790961] [<ffffff90085ca548>] platform_drv_probe+0x7c/0xd0
[    0.790972] [<ffffff90085c76ac>] driver_probe_device+0x1b4/0x3bc
[    0.790982] [<ffffff90085c7ac8>] __device_attach_driver+0xc8/0xf4
[    0.790996] [<ffffff90085c4bfc>] bus_for_each_drv+0xb4/0xe4
[    0.791006] [<ffffff90085c7414>] __device_attach+0xd0/0x158
[    0.791016] [<ffffff90085c7b18>] device_initial_probe+0x24/0x30
[    0.791026] [<ffffff90085c648c>] bus_probe_device+0x50/0xe4
[    0.791038] [<ffffff90085c35b8>] device_add+0x3a4/0x76c
[    0.791051] [<ffffff90087d0e84>] of_device_add+0x74/0x84
[    0.791062] [<ffffff90087d19b8>] of_platform_device_create_pdata+0xc0/0x100
[    0.791073] [<ffffff90087d1a2c>] of_platform_device_create+0x34/0x40
[    0.791086] [<ffffff900903c910>] of_platform_default_populate_init+0x58/0x78
[    0.791097] [<ffffff90080831fc>] do_one_initcall+0x88/0x160
[    0.791109] [<ffffff90090010ac>] kernel_init_freeable+0x264/0x31c
[    0.791123] [<ffffff9008a25bd0>] kernel_init+0x18/0x11c
[    0.791133] [<ffffff9008082ec0>] ret_from_fork+0x10/0x50
[    0.793717] console [pstore-1] enabled
[    0.797845] pstore: Registered ramoops as persistent store backend
[    0.804647] ramoops: attached 0x100000@0xf7edc000, ecc: 0/0

Fixes: 663deb4788 ("pstore: Allow prz to control need for locking")
Fixes: 109704492e ("pstore: Make spinlock per zone instead of global")
Reported-by: Brian Norris <briannorris@chromium.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
2017-02-13 10:25:52 -08:00
Brian Norris
8672aed7bd pstore: don't OOPS when there are no ftrace zones
We'll OOPS in ramoops_get_next_prz() if the platform didn't ask for any
ftrace zones (i.e., cxt->fprzs will be NULL). Let's just skip this
entire FTRACE section if there's no 'fprzs'.

Regression seen on a coreboot/depthcharge-based Chromebook.

Fixes: 2fbea82bbb ("pstore: Merge per-CPU ftrace records into one")
Cc: Joel Fernandes <joelaf@google.com>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Brian Norris <briannorris@chromium.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
2017-02-09 11:49:49 -08:00
Linus Torvalds
52281b38bc Improvements and fixes to pstore subsystem:
- Add additional checks for bad platform data
 
 - Remove bounce buffer in console writer
 
 - Protect read/unlink race with a mutex
 
 - Correctly give up during dump locking failures
 
 - Increase ftrace bandwidth by splitting ftrace buffers per CPU
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Merge tag 'pstore-v4.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

Pull pstore updates from Kees Cook:
 "Improvements and fixes to pstore subsystem:

   - add additional checks for bad platform data

   - remove bounce buffer in console writer

   - protect read/unlink race with a mutex

   - correctly give up during dump locking failures

   - increase ftrace bandwidth by splitting ftrace buffers per CPU"

* tag 'pstore-v4.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  ramoops: add pdata NULL check to ramoops_probe
  pstore: Convert console write to use ->write_buf
  pstore: Protect unlink with read_mutex
  pstore: Use global ftrace filters for function trace filtering
  ftrace: Provide API to use global filtering for ftrace ops
  pstore: Clarify context field przs as dprzs
  pstore: improve error report for failed setup
  pstore: Merge per-CPU ftrace records into one
  pstore: Add ftrace timestamp counter
  ramoops: Split ftrace buffer space into per-CPU zones
  pstore: Make ramoops_init_przs generic for other prz arrays
  pstore: Allow prz to control need for locking
  pstore: Warn on PSTORE_TYPE_PMSG using deprecated function
  pstore: Make spinlock per zone instead of global
  pstore: Actually give up during locking failure
2016-12-13 09:16:11 -08:00
Kees Cook
fc46d4e453 ramoops: add pdata NULL check to ramoops_probe
This adds a check for a NULL platform data, which should only be possible
if a driver incorrectly sets up a probe request without also having defined
the platform_data structure. This is based on a patch from Geliang Tang.

Signed-off-by: Kees Cook <keescook@chromium.org>
2016-11-15 16:34:32 -08:00
Namhyung Kim
70ad35db33 pstore: Convert console write to use ->write_buf
Maybe I'm missing something, but I don't know why it needs to copy the
input buffer to psinfo->buf and then write.  Instead we can write the
input buffer directly.  The only implementation that supports console
message (i.e. ramoops) already does it for ftrace messages.

For the upcoming virtio backend driver, it needs to protect psinfo->buf
overwritten from console messages.  If it could use ->write_buf method
instead of ->write, the problem will be solved easily.

Cc: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
2016-11-15 16:34:32 -08:00
Namhyung Kim
e9e360b08a pstore: Protect unlink with read_mutex
When update_ms is set, pstore_get_records() will be called when there's
a new entry.  But unlink can be called at the same time and might
contend with the open-read-close loop.  Depending on the implementation
of platform driver, it may be safe or not.  But I think it'd be better
to protect those race in the first place.

Cc: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
2016-11-15 16:34:31 -08:00
Joel Fernandes
7a0032f504 pstore: Use global ftrace filters for function trace filtering
Currently, pstore doesn't have any filters setup for function tracing.
This has the associated overhead and may not be useful for users looking
for tracing specific set of functions.

ftrace's regular function trace filtering is done writing to
tracing/set_ftrace_filter however this is not available if not requested.
In order to be able to use this feature, the support to request global
filtering introduced earlier in the series should be requested before
registering the ftrace ops. Here we do the same.

Signed-off-by: Joel Fernandes <joelaf@google.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
2016-11-15 16:34:30 -08:00
Kees Cook
a5d23b956c pstore: Clarify context field przs as dprzs
Since "przs" (persistent ram zones) is a general name in the code now, so
rename the Oops-dump zones to dprzs from przs.

Based on a patch from Nobuhiro Iwamatsu.

Signed-off-by: Kees Cook <keescook@chromium.org>
2016-11-15 16:34:29 -08:00
Kees Cook
c443a5f3f1 pstore: improve error report for failed setup
When setting ramoops record sizes, sometimes it's not clear which
parameters contributed to the allocation failure. This adds a per-zone
name and expands the failure reports.

Signed-off-by: Kees Cook <keescook@chromium.org>
2016-11-15 16:34:28 -08:00
Joel Fernandes
2fbea82bbb pstore: Merge per-CPU ftrace records into one
Up until this patch, each of the per CPU ftrace buffers appear as a
separate ftrace-ramoops-N file. In this patch we merge all the zones into
one and populate a single ftrace-ramoops-0 file.

Signed-off-by: Joel Fernandes <joelaf@google.com>
[kees: clarified variables names, added -ENOMEM handling]
Signed-off-by: Kees Cook <keescook@chromium.org>
2016-11-15 16:34:28 -08:00
Joel Fernandes
fbccdeb8d7 pstore: Add ftrace timestamp counter
In preparation for merging the per CPU buffers into one buffer when
we retrieve the pstore ftrace data, we store the timestamp as a
counter in the ftrace pstore record.  We store the CPU number as well
if !PSTORE_CPU_IN_IP, in this case we shift the counter and may lose
ordering there but we preserve the same record size. The timestamp counter
is also racy, and not doing any locking or synchronization here results
in the benefit of lower overhead. Since we don't care much here for exact
ordering of function traces across CPUs, we don't synchronize and may lose
some counter updates but I'm ok with that.

Using trace_clock() results in much lower performance so avoid using it
since we don't want accuracy in timestamp and need a rough ordering to
perform merge.

Signed-off-by: Joel Fernandes <joelaf@google.com>
[kees: updated commit message, added comments]
Signed-off-by: Kees Cook <keescook@chromium.org>
2016-11-15 16:34:27 -08:00
Joel Fernandes
a1cf53ac6d ramoops: Split ftrace buffer space into per-CPU zones
If the RAMOOPS_FLAG_FTRACE_PER_CPU flag is passed to ramoops pdata, split
the ftrace space into multiple zones depending on the number of CPUs.

This speeds up the performance of function tracing by about 280% in my
tests as we avoid the locking. The trade off being lesser space available
per CPU. Let the ramoops user decide which option they want based on pdata
flag.

Signed-off-by: Joel Fernandes <joelaf@google.com>
[kees: added max_ftrace_cnt to track size, added DT logic and docs]
Signed-off-by: Kees Cook <keescook@chromium.org>
2016-11-15 16:34:26 -08:00
Kees Cook
de83209249 pstore: Make ramoops_init_przs generic for other prz arrays
Currently ramoops_init_przs() is hard wired only for panic dump zone
array. In preparation for the ftrace zone array (one zone per-cpu) and pmsg
zone array, make the function more generic to be able to handle this case.

Heavily based on similar work from Joel Fernandes.

Signed-off-by: Kees Cook <keescook@chromium.org>
2016-11-15 16:34:25 -08:00
Joel Fernandes
663deb4788 pstore: Allow prz to control need for locking
In preparation of not locking at all for certain buffers depending on if
there's contention, make locking optional depending on the initialization
of the prz.

Signed-off-by: Joel Fernandes <joelaf@google.com>
[kees: moved locking flag into prz instead of via caller arguments]
Signed-off-by: Kees Cook <keescook@chromium.org>
2016-11-15 16:34:25 -08:00
Joel Fernandes
d8991f51e5 pstore: Warn on PSTORE_TYPE_PMSG using deprecated function
PMSG now uses ramoops_pstore_write_buf_user() instead of ...write_buf().
Print a ratelimited warning if gets accidentally called.

Signed-off-by: Joel Fernandes <joelaf@google.com>
[kees: adjusted commit log and added -EINVAL return]
Signed-off-by: Kees Cook <keescook@chromium.org>
2016-11-11 10:36:46 -08:00
Joel Fernandes
109704492e pstore: Make spinlock per zone instead of global
Currently pstore has a global spinlock for all zones. Since the zones
are independent and modify different areas of memory, there's no need
to have a global lock, so we should use a per-zone lock as introduced
here. Also, when ramoops's ftrace use-case has a FTRACE_PER_CPU flag
introduced later, which splits the ftrace memory area into a single zone
per CPU, it will eliminate the need for locking. In preparation for this,
make the locking optional.

Signed-off-by: Joel Fernandes <joelaf@google.com>
[kees: updated commit message]
Signed-off-by: Kees Cook <keescook@chromium.org>
2016-11-11 10:35:37 -08:00
Li Pengcheng
959217c84c pstore: Actually give up during locking failure
Without a return after the pr_err(), dumps will collide when two threads
call pstore_dump() at the same time.

Signed-off-by: Liu Hailong <liuhailong5@huawei.com>
Signed-off-by: Li Pengcheng <lipengcheng8@huawei.com>
Signed-off-by: Li Zhong <lizhong11@hisilicon.com>
[kees: improved commit message]
Signed-off-by: Kees Cook <keescook@chromium.org>
2016-11-08 16:44:33 -08:00
Mauro Carvalho Chehab
8c27ceff36 docs: fix locations of several documents that got moved
The previous patch renamed several files that are cross-referenced
along the Kernel documentation. Adjust the links to point to
the right places.

Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2016-10-24 08:12:35 -02:00
Linus Torvalds
101105b171 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull more vfs updates from Al Viro:
 ">rename2() work from Miklos + current_time() from Deepa"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  fs: Replace current_fs_time() with current_time()
  fs: Replace CURRENT_TIME_SEC with current_time() for inode timestamps
  fs: Replace CURRENT_TIME with current_time() for inode timestamps
  fs: proc: Delete inode time initializations in proc_alloc_inode()
  vfs: Add current_time() api
  vfs: add note about i_op->rename changes to porting
  fs: rename "rename2" i_op to "rename"
  vfs: remove unused i_op->rename
  fs: make remaining filesystems use .rename2
  libfs: support RENAME_NOREPLACE in simple_rename()
  fs: support RENAME_NOREPLACE for local filesystems
  ncpfs: fix unused variable warning
2016-10-10 20:16:43 -07:00
Deepa Dinamani
078cd8279e fs: Replace CURRENT_TIME with current_time() for inode timestamps
CURRENT_TIME macro is not appropriate for filesystems as it
doesn't use the right granularity for filesystem timestamps.
Use current_time() instead.

CURRENT_TIME is also not y2038 safe.

This is also in preparation for the patch that transitions
vfs timestamps to use 64 bit time and hence make them
y2038 safe. As part of the effort current_time() will be
extended to do range checks. Hence, it is necessary for all
file system timestamps to use current_time(). Also,
current_time() will be transitioned along with vfs to be
y2038 safe.

Note that whenever a single call to current_time() is used
to change timestamps in different inodes, it is because they
share the same time granularity.

Signed-off-by: Deepa Dinamani <deepa.kernel@gmail.com>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Felipe Balbi <balbi@kernel.org>
Acked-by: Steven Whitehouse <swhiteho@redhat.com>
Acked-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Acked-by: David Sterba <dsterba@suse.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-09-27 21:06:21 -04:00
Geliang Tang
f88baf68eb ramoops: move spin_lock_init after kmalloc error checking
If cxt->pstore.buf allocated failed, no need to initialize
cxt->pstore.buf_lock. So this patch moves spin_lock_init() after the
error checking.

Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
2016-09-08 15:01:13 -07:00
Andrew Bresticker
d771fdf941 pstore/ram: Use memcpy_fromio() to save old buffer
The ramoops buffer may be mapped as either I/O memory or uncached
memory.  On ARM64, this results in a device-type (strongly-ordered)
mapping.  Since unnaligned accesses to device-type memory will
generate an alignment fault (regardless of whether or not strict
alignment checking is enabled), it is not safe to use memcpy().
memcpy_fromio() is guaranteed to only use aligned accesses, so use
that instead.

Signed-off-by: Andrew Bresticker <abrestic@chromium.org>
Signed-off-by: Enric Balletbo Serra <enric.balletbo@collabora.com>
Reviewed-by: Puneet Kumar <puneetster@chromium.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: stable@vger.kernel.org
2016-09-08 15:01:12 -07:00
Furquan Shaikh
7e75678d23 pstore/ram: Use memcpy_toio instead of memcpy
persistent_ram_update uses vmap / iomap based on whether the buffer is in
memory region or reserved region. However, both map it as non-cacheable
memory. For armv8 specifically, non-cacheable mapping requests use a
memory type that has to be accessed aligned to the request size. memcpy()
doesn't guarantee that.

Signed-off-by: Furquan Shaikh <furquan@google.com>
Signed-off-by: Enric Balletbo Serra <enric.balletbo@collabora.com>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-by: Olof Johansson <olofj@chromium.org>
Tested-by: Furquan Shaikh <furquan@chromium.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: stable@vger.kernel.org
2016-09-08 15:01:11 -07:00
Mark Salyzyn
5bf6d1b927 pstore/pmsg: drop bounce buffer
Removing a bounce buffer copy operation in the pmsg driver path is
always better. We also gain in overall performance by not requesting
a vmalloc on every write as this can cause precious RT tasks, such
as user facing media operation, to stall while memory is being
reclaimed. Added a write_buf_user to the pstore functions, a backup
platform write_buf_user that uses the small buffer that is part of
the instance, and implemented a ramoops write_buf_user that only
supports PSTORE_TYPE_PMSG.

Signed-off-by: Mark Salyzyn <salyzyn@android.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
2016-09-08 15:01:10 -07:00
Namhyung Kim
79d955af71 pstore/ram: Set pstore flags dynamically
The ramoops can be configured to enable each pstore type by setting
their size.  In that case, it'd be better not to register disabled types
in the first place.

Cc: Anton Vorontsov <anton@enomsg.org>
Cc: Colin Cross <ccross@android.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Tony Luck <tony.luck@intel.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
2016-09-08 15:01:09 -07:00
Namhyung Kim
c950fd6f20 pstore: Split pstore fragile flags
This patch adds new PSTORE_FLAGS for each pstore type so that they can
be enabled separately.  This is a preparation for ongoing virtio-pstore
work to support those types flexibly.

The PSTORE_FLAGS_FRAGILE is changed to PSTORE_FLAGS_DMESG to preserve the
original behavior.

Cc: Anton Vorontsov <anton@enomsg.org>
Cc: Colin Cross <ccross@android.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Tony Luck <tony.luck@intel.com>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Len Brown <lenb@kernel.org>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: linux-acpi@vger.kernel.org
Cc: linux-efi@vger.kernel.org
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
[kees: retained "FRAGILE" for now to make merges easier]
Signed-off-by: Kees Cook <keescook@chromium.org>
2016-09-08 15:01:08 -07:00
Sebastian Andrzej Siewior
d5a9bf0b38 pstore/core: drop cmpxchg based updates
I have here a FPGA behind PCIe which exports SRAM which I use for
pstore. Now it seems that the FPGA no longer supports cmpxchg based
updates and writes back 0xff…ff and returns the same.  This leads to
crash during crash rendering pstore useless.
Since I doubt that there is much benefit from using cmpxchg() here, I am
dropping this atomic access and use the spinlock based version.

Cc: Anton Vorontsov <anton@enomsg.org>
Cc: Colin Cross <ccross@android.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Rabin Vincent <rabinv@axis.com>
Tested-by: Rabin Vincent <rabinv@axis.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
[kees: remove "_locked" suffix since it's the only option now]
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: stable@vger.kernel.org
2016-09-08 15:00:47 -07:00
Sebastian Andrzej Siewior
4407de74df pstore/ramoops: fixup driver removal
A basic rmmod ramoops segfaults. Let's see why.

Since commit 34f0ec82e0 ("pstore: Correct the max_dump_cnt clearing of
ramoops") sets ->max_dump_cnt to zero before looping over ->przs but we
didn't use it before that either.

And since commit ee1d267423 ("pstore: add pstore unregister") we free
that memory on rmmod.

But even then, we looped until a NULL pointer or ERR. I don't see where
it is ensured that the last member is NULL. Let's try this instead:
simply error recovery and free. Clean up in error case where resources
were allocated. And then, in the free path, rely on ->max_dump_cnt in
the free path.

Cc: Anton Vorontsov <anton@enomsg.org>
Cc: Colin Cross <ccross@android.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: stable@vger.kernel.org # 4.4.x-
2016-09-08 14:58:00 -07:00
Hiraku Toyooka
e976e56423 ramoops: use persistent_ram_free() instead of kfree() for freeing prz
persistent_ram_zone(=prz) structures are allocated by persistent_ram_new(),
which includes vmap() or ioremap(). But they are currently freed by
kfree(). This uses persistent_ram_free() for correct this asymmetry usage.

Signed-off-by: Hiraku Toyooka <hiraku.toyooka.gu@hitachi.com>
Signed-off-by: Nobuhiro Iwamatsu <nobuhiro.iwamatsu.kw@hitachi.com>
Cc: Mark Salyzyn <salyzyn@android.com>
Cc: Seiji Aguchi <seiji.aguchi.tr@hitachi.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
2016-08-05 11:21:46 -07:00
Kees Cook
529182e204 ramoops: use DT reserved-memory bindings
Instead of a ramoops-specific node, use a child node of /reserved-memory.
This requires that of_platform_device_create() be explicitly called
for the node, though, since "/reserved-memory" does not have its own
"compatible" property.

Suggested-by: Rob Herring <robh@kernel.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: Rob Herring <robh@kernel.org>
2016-08-05 11:21:36 -07:00
Greg Hackmann
35da60941e pstore/ram: add Device Tree bindings
ramoops is one of the remaining places where ARM vendors still rely on
board-specific shims.  Device Tree lets us replace those shims with
generic code.

These bindings mirror the ramoops module parameters, with two small
differences:

(1) dump_oops becomes an optional "no-dump-oops" property, since ramoops
    sets dump_oops=1 by default.

(2) mem_type=1 becomes the more self-explanatory "unbuffered" property.

Signed-off-by: Greg Hackmann <ghackmann@google.com>
[fixed platform_get_drvdata() crash, thanks to Brian Norris]
[switched from u64 to u32 to simplify code, various whitespace fixes]
[use dev_of_node() to gain code-elimination for CONFIG_OF=n]
Signed-off-by: Kees Cook <keescook@chromium.org>
2016-06-14 11:34:39 -07:00
Geliang Tang
52d210d961 pstore: drop file opened reference count
In ee1d267423 ("pstore: add pstore unregister") I added:
	.owner = THIS_MODULE,
in both pstore_fs_type and pstore_file_operations to increase a reference
count when pstore filesystem is mounted and pstore file is opened.

But, it's repetitive. There is no need to increase the opened reference
count. We only need to increase the mounted reference count. When a file
is opened, the filesystem can't be unmounted. Hence the pstore module
can't be unloaded either.

So I drop the opened reference count in this patch.

Fixes: ee1d267423 ("pstore: add pstore unregister")
Signed-off-by: Geliang Tang <geliangtang@163.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
2016-06-02 11:24:52 -07:00
Geliang Tang
8cfc8ddc99 pstore: add lzo/lz4 compression support
Like zlib compression in pstore, this patch added lzo and lz4
compression support so that users can have more options and better
compression ratio.

The original code treats the compressed data together with the
uncompressed ECC correction notice by using zlib decompress. The
ECC correction notice is missing in the decompression process. The
treatment also makes lzo and lz4 not working. So I treat them
separately by using pstore_decompress() to treat the compressed
data, and memcpy() to treat the uncompressed ECC correction notice.

Signed-off-by: Geliang Tang <geliangtang@163.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
2016-06-02 10:59:31 -07:00
Namhyung Kim
235f6d157d pstore: Cleanup pstore_dump()
The code is duplicate between compression is enabled or not.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
2016-05-31 12:36:45 -07:00
Namhyung Kim
98e44fda2e pstore: Enable compression on normal path (again)
The commit f0e2efcfd2 ("pstore: do not use message compression
without lock") added a check to 'is_locked' to avoid breakage in
concurrent accesses.  But it has a side-effect of disabling compression
on normal path since 'is_locked' variable is not set.  As normal path
always takes the lock, it should be initialized to 1.

This also makes the unlock code a bit simpler.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
2016-05-31 12:36:44 -07:00
Kees Cook
a1db8060f5 ramoops: Only unregister when registered
While none of the "fragile" pstore backends unregister yet, if they
ever did, the unregistering code for the non-dump targets might get
confused. This adds a check for fragile backends on unregister.

Signed-off-by: Kees Cook <keescook@chromium.org>
2016-05-31 12:36:44 -07:00
Kirill A. Shutemov
09cbfeaf1a mm, fs: get rid of PAGE_CACHE_* and page_cache_{get,release} macros
PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} macros were introduced *long* time
ago with promise that one day it will be possible to implement page
cache with bigger chunks than PAGE_SIZE.

This promise never materialized.  And unlikely will.

We have many places where PAGE_CACHE_SIZE assumed to be equal to
PAGE_SIZE.  And it's constant source of confusion on whether
PAGE_CACHE_* or PAGE_* constant should be used in a particular case,
especially on the border between fs and mm.

Global switching to PAGE_CACHE_SIZE != PAGE_SIZE would cause to much
breakage to be doable.

Let's stop pretending that pages in page cache are special.  They are
not.

The changes are pretty straight-forward:

 - <foo> << (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>;

 - <foo> >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>;

 - PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} -> PAGE_{SIZE,SHIFT,MASK,ALIGN};

 - page_cache_get() -> get_page();

 - page_cache_release() -> put_page();

This patch contains automated changes generated with coccinelle using
script below.  For some reason, coccinelle doesn't patch header files.
I've called spatch for them manually.

The only adjustment after coccinelle is revert of changes to
PAGE_CAHCE_ALIGN definition: we are going to drop it later.

There are few places in the code where coccinelle didn't reach.  I'll
fix them manually in a separate patch.  Comments and documentation also
will be addressed with the separate patch.

virtual patch

@@
expression E;
@@
- E << (PAGE_CACHE_SHIFT - PAGE_SHIFT)
+ E

@@
expression E;
@@
- E >> (PAGE_CACHE_SHIFT - PAGE_SHIFT)
+ E

@@
@@
- PAGE_CACHE_SHIFT
+ PAGE_SHIFT

@@
@@
- PAGE_CACHE_SIZE
+ PAGE_SIZE

@@
@@
- PAGE_CACHE_MASK
+ PAGE_MASK

@@
expression E;
@@
- PAGE_CACHE_ALIGN(E)
+ PAGE_ALIGN(E)

@@
expression E;
@@
- page_cache_get(E)
+ get_page(E)

@@
expression E;
@@
- page_cache_release(E)
+ put_page(E)

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-04-04 10:41:08 -07:00
Wiebe, Wladislav (Nokia - DE/Ulm)
764fd639d7 pstore: Add support for 64 Bit address space
Some architectures have their reserved RAM in 64 Bit address space.
Therefore convert mem_address module parameter to ullong.

Signed-off-by: Wladislav Wiebe <wladislav.wiebe@nokia.com>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Tony Luck <tony.luck@intel.com>
2016-03-10 09:43:36 -08:00
Al Viro
5955102c99 wrappers for ->i_mutex access
parallel to mutex_{lock,unlock,trylock,is_locked,lock_nested},
inode_foo(inode) being mutex_foo(&inode->i_mutex).

Please, use those for access to ->i_mutex; over the coming cycle
->i_mutex will become rwsem, with ->lookup() done with it held
only shared.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-01-22 18:04:28 -05:00
Geliang Tang
306e5c2a3c pstore: fix code comment to match code
Fix code comment about kmsg_dump register so it matches the code.

Signed-off-by: Geliang Tang <geliangtang@163.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
2015-11-02 13:41:52 -08:00
Geliang Tang
7e26e9ff0a pstore: Fix return type of pstore_is_mounted()
This patch changes return type of pstore_is_mounted from int to bool.

Signed-off-by: Geliang Tang <geliangtang@163.com>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Tony Luck <tony.luck@intel.com>
2015-10-22 10:57:33 -07:00
Geliang Tang
ee1d267423 pstore: add pstore unregister
pstore doesn't support unregistering yet. It was marked as TODO.
This patch adds some code to fix it:
 1) Add functions to unregister kmsg/console/ftrace/pmsg.
 2) Add a function to free compression buffer.
 3) Unmap the memory and free it.
 4) Add a function to unregister pstore filesystem.

Signed-off-by: Geliang Tang <geliangtang@163.com>
Acked-by: Kees Cook <keescook@chromium.org>
[Removed __exit annotation from ramoops_remove(). Reported by Arnd Bergmann]
Signed-off-by: Tony Luck <tony.luck@intel.com>
2015-10-22 08:59:18 -07:00
Geliang Tang
1873041152 pstore: add a helper function pstore_register_kmsg
Add a new wrapper function pstore_register_kmsg to keep the
consistency with other similar pstore_register_* functions.

Signed-off-by: Geliang Tang <geliangtang@163.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
2015-10-21 09:27:10 -07:00
Geliang Tang
549b39a9e7 pstore: add vmalloc error check
If vmalloc fails, make write_pmsg return -ENOMEM.

Signed-off-by: Geliang Tang <geliangtang@163.com>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Tony Luck <tony.luck@intel.com>
2015-10-21 09:27:10 -07:00
Linus Torvalds
0cbee99269 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace
Pull user namespace updates from Eric Biederman:
 "Long ago and far away when user namespaces where young it was realized
  that allowing fresh mounts of proc and sysfs with only user namespace
  permissions could violate the basic rule that only root gets to decide
  if proc or sysfs should be mounted at all.

  Some hacks were put in place to reduce the worst of the damage could
  be done, and the common sense rule was adopted that fresh mounts of
  proc and sysfs should allow no more than bind mounts of proc and
  sysfs.  Unfortunately that rule has not been fully enforced.

  There are two kinds of gaps in that enforcement.  Only filesystems
  mounted on empty directories of proc and sysfs should be ignored but
  the test for empty directories was insufficient.  So in my tree
  directories on proc, sysctl and sysfs that will always be empty are
  created specially.  Every other technique is imperfect as an ordinary
  directory can have entries added even after a readdir returns and
  shows that the directory is empty.  Special creation of directories
  for mount points makes the code in the kernel a smidge clearer about
  it's purpose.  I asked container developers from the various container
  projects to help test this and no holes were found in the set of mount
  points on proc and sysfs that are created specially.

  This set of changes also starts enforcing the mount flags of fresh
  mounts of proc and sysfs are consistent with the existing mount of
  proc and sysfs.  I expected this to be the boring part of the work but
  unfortunately unprivileged userspace winds up mounting fresh copies of
  proc and sysfs with noexec and nosuid clear when root set those flags
  on the previous mount of proc and sysfs.  So for now only the atime,
  read-only and nodev attributes which userspace happens to keep
  consistent are enforced.  Dealing with the noexec and nosuid
  attributes remains for another time.

  This set of changes also addresses an issue with how open file
  descriptors from /proc/<pid>/ns/* are displayed.  Recently readlink of
  /proc/<pid>/fd has been triggering a WARN_ON that has not been
  meaningful since it was added (as all of the code in the kernel was
  converted) and is not now actively wrong.

  There is also a short list of issues that have not been fixed yet that
  I will mention briefly.

  It is possible to rename a directory from below to above a bind mount.
  At which point any directory pointers below the renamed directory can
  be walked up to the root directory of the filesystem.  With user
  namespaces enabled a bind mount of the bind mount can be created
  allowing the user to pick a directory whose children they can rename
  to outside of the bind mount.  This is challenging to fix and doubly
  so because all obvious solutions must touch code that is in the
  performance part of pathname resolution.

  As mentioned above there is also a question of how to ensure that
  developers by accident or with purpose do not introduce exectuable
  files on sysfs and proc and in doing so introduce security regressions
  in the current userspace that will not be immediately obvious and as
  such are likely to require breaking userspace in painful ways once
  they are recognized"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
  vfs: Remove incorrect debugging WARN in prepend_path
  mnt: Update fs_fully_visible to test for permanently empty directories
  sysfs: Create mountpoints with sysfs_create_mount_point
  sysfs: Add support for permanently empty directories to serve as mount points.
  kernfs: Add support for always empty directories.
  proc: Allow creating permanently empty directories that serve as mount points
  sysctl: Allow creating permanently empty directories that serve as mountpoints.
  fs: Add helper functions for permanently empty directories.
  vfs: Ignore unlocked mounts in fs_fully_visible
  mnt: Modify fs_fully_visible to deal with locked ro nodev and atime
  mnt: Refactor the logic for mounting sysfs and proc in a user namespace
2015-07-03 15:20:57 -07:00
Eric W. Biederman
f9bb48825a sysfs: Create mountpoints with sysfs_create_mount_point
This allows for better documentation in the code and
it allows for a simpler and fully correct version of
fs_fully_visible to be written.

The mount points converted and their filesystems are:
/sys/hypervisor/s390/       s390_hypfs
/sys/kernel/config/         configfs
/sys/kernel/debug/          debugfs
/sys/firmware/efi/efivars/  efivarfs
/sys/fs/fuse/connections/   fusectl
/sys/fs/pstore/             pstore
/sys/kernel/tracing/        tracefs
/sys/fs/cgroup/             cgroup
/sys/kernel/security/       securityfs
/sys/fs/selinux/            selinuxfs
/sys/fs/smackfs/            smackfs

Cc: stable@vger.kernel.org
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2015-07-01 10:36:47 -05:00
Wang Long
078550569e ramoops: make it possible to change mem_type param.
If we set ramoops.mem_type=1 in command line, the current
code can not change mem_type to 1, because it is assigned
to 0 in function ramoops_register_dummy.

This patch make it possible to change mem_type parameter
in command line.

Signed-off-by: Wang Long <long.wanglong@huawei.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
2015-05-21 09:52:29 -07:00
Ben Zhang
e036bd330d pstore/ram: verify ramoops header before saving record
On some devices the persistent memory contains junk after a cold boot,
and /dev/pstore/dmesg-ramoops-* are created with random data which is
not the result of a kernel crash.

This patch adds a ramoops header check and skips any
persistent_ram_zone that does not have a valid header.

Signed-off-by: Ben Zhang <benzh@chromium.org>
Signed-off-by: Tony Luck <tony.luck@intel.com>
2015-05-21 09:50:34 -07:00