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: NKees Cook <keescook@chromium.org>

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: NJoel Fernandes <joelaf@google.com>
[kees: clarified variables names, added -ENOMEM handling]
Signed-off-by: NKees Cook <keescook@chromium.org>

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: NJoel Fernandes <joelaf@google.com>
[kees: added max_ftrace_cnt to track size, added DT logic and docs]
Signed-off-by: NKees Cook <keescook@chromium.org>

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: NKees Cook <keescook@chromium.org>

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: NJoel Fernandes <joelaf@google.com>
[kees: moved locking flag into prz instead of via caller arguments]
Signed-off-by: NKees Cook <keescook@chromium.org>

PMSG now uses ramoops_pstore_write_buf_user() instead of ...write_buf().
Print a ratelimited warning if gets accidentally called.
Signed-off-by: NJoel Fernandes <joelaf@google.com>
[kees: adjusted commit log and added -EINVAL return]
Signed-off-by: NKees Cook <keescook@chromium.org>

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: NGeliang Tang <geliangtang@gmail.com>
Signed-off-by: NKees Cook <keescook@chromium.org>

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: NMark Salyzyn <salyzyn@android.com>
Signed-off-by: NKees Cook <keescook@chromium.org>

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: NNamhyung Kim <namhyung@kernel.org>
Signed-off-by: NKees Cook <keescook@chromium.org>

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: NNamhyung Kim <namhyung@kernel.org>
[kees: retained "FRAGILE" for now to make merges easier]
Signed-off-by: NKees Cook <keescook@chromium.org>

A basic rmmod ramoops segfaults. Let's see why.

Since commit 34f0ec82 ("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 ee1d2674 ("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: NNamhyung Kim <namhyung@kernel.org>
Signed-off-by: NSebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: NKees Cook <keescook@chromium.org>
Cc: stable@vger.kernel.org # 4.4.x-

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: NHiraku Toyooka <hiraku.toyooka.gu@hitachi.com>
Signed-off-by: NNobuhiro Iwamatsu <nobuhiro.iwamatsu.kw@hitachi.com>
Cc: Mark Salyzyn <salyzyn@android.com>
Cc: Seiji Aguchi <seiji.aguchi.tr@hitachi.com>
Signed-off-by: NKees Cook <keescook@chromium.org>

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: NRob Herring <robh@kernel.org>
Signed-off-by: NKees Cook <keescook@chromium.org>
Acked-by: NRob Herring <robh@kernel.org>

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: NGreg 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: NKees Cook <keescook@chromium.org>

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: NGeliang Tang <geliangtang@163.com>
Signed-off-by: NKees Cook <keescook@chromium.org>

Some architectures have their reserved RAM in 64 Bit address space.
Therefore convert mem_address module parameter to ullong.
Signed-off-by: NWladislav Wiebe <wladislav.wiebe@nokia.com>
Acked-by: NKees Cook <keescook@chromium.org>
Signed-off-by: NTony Luck <tony.luck@intel.com>

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: NGeliang Tang <geliangtang@163.com>
Acked-by: NKees Cook <keescook@chromium.org>
[Removed __exit annotation from ramoops_remove(). Reported by Arnd Bergmann]
Signed-off-by: NTony Luck <tony.luck@intel.com>

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: NWang Long <long.wanglong@huawei.com>
Acked-by: NTony Lindgren <tony@atomide.com>
Signed-off-by: NTony Luck <tony.luck@intel.com>

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: NBen Zhang <benzh@chromium.org>
Signed-off-by: NTony Luck <tony.luck@intel.com>

The value of cxt->record_size does not change in the loop,
so this patch optimize the assign statement by dropping
sz entirely and using cxt->record_size in its place.
Signed-off-by: NWang Long <long.wanglong@huawei.com>
Acked-by: NKees Cook <keescook@chromium.org>
Signed-off-by: NTony Luck <tony.luck@intel.com>

In the function ramoops_probe, the console_size, pmsg_size,
ftrace_size may be update because the value is not the power
of two. We should update the module parameter variables
as well so they are visible through /sys/module/ramoops/parameters
correctly.
Signed-off-by: NWang Long <long.wanglong@huawei.com>
Acked-by: NMark Salyzyn <salyzyn@android.com>
Acked-by: NKees Cook <keescook@chromium.org>
Signed-off-by: NTony Luck <tony.luck@intel.com>

A secured user-space accessible pstore object. Writes
to /dev/pmsg0 are appended to the buffer, on reboot
the persistent contents are available in
/sys/fs/pstore/pmsg-ramoops-[ID].

One possible use is syslogd, or other daemon, can
write messages, then on reboot provides a means to
triage user-space activities leading up to a panic
as a companion to the pstore dmesg or console logs.
Signed-off-by: NMark Salyzyn <salyzyn@android.com>
Acked-by: NKees Cook <keescook@chromium.org>
Signed-off-by: NTony Luck <tony.luck@intel.com>

ramoops_pstore_read fails to return the next in a prz
series after first zero-sized entry, not venturing to
the next non-zero entry.
Signed-off-by: NMark Salyzyn <salyzyn@android.com>
Acked-by: NKees Cook <keescook@chromium.org>
Signed-off-by: NTony Luck <tony.luck@intel.com>

All previous checks will fail with error if memory size
is not sufficient to register a zone, so this legacy
check has become redundant.
Signed-off-by: NMark Salyzyn <salyzyn@android.com>
Acked-by: NKees Cook <keescook@chromium.org>
Signed-off-by: NTony Luck <tony.luck@intel.com>

On some ARMs the memory can be mapped pgprot_noncached() and still
be working for atomic operations. As pointed out by Colin Cross
<ccross@android.com>, in some cases you do want to use
pgprot_noncached() if the SoC supports it to see a debug printk
just before a write hanging the system.

On ARMs, the atomic operations on strongly ordered memory are
implementation defined. So let's provide an optional kernel parameter
for configuring pgprot_noncached(), and use pgprot_writecombine() by
default.

Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Rob Herring <robherring2@gmail.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Anton Vorontsov <anton@enomsg.org>
Cc: Colin Cross <ccross@android.com>
Cc: Olof Johansson <olof@lixom.net>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: stable@vger.kernel.org
Acked-by: NKees Cook <keescook@chromium.org>
Signed-off-by: NTony Lindgren <tony@atomide.com>
Signed-off-by: NTony Luck <tony.luck@intel.com>

pstore compression/decompression was added during 3.12.
The ramoops driver prepends a "====timestamp.timestamp-C|D\n"
header to the compressed record before handing it over to pstore
driver which doesn't know about the header. In pstore_decompress(),
the pstore driver reads the first "==" as a zlib header, so the
decompression always fails. For example, this causes the driver
to write /dev/pstore/dmesg-ramoops-0.enc.z instead of
/dev/pstore/dmesg-ramoops-0.

This patch makes the ramoops driver remove the header before
pstore decompression.
Signed-off-by: NBen Zhang <benzh@chromium.org>
Acked-by: NKees Cook <keescook@chromium.org>
Signed-off-by: NTony Luck <tony.luck@intel.com>

A platform_driver does not need to set an owner, it will be populated by the
driver core.
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

In case that ramoops_init_przs failed, max_dump_cnt won't be reset to
zero in error handle path.
Signed-off-by: NLiu ShuoX <shuox.liu@intel.com>
Acked-by: NKees Cook <keescook@chromium.org>
Signed-off-by: NTony Luck <tony.luck@intel.com>

ramoops_get_next_prz get the prz according the paramters. If it get a
uninitialized prz, access its members by following persistent_ram_old_size(prz)
will cause a NULL pointer crash.
Ex: if ftrace_size is 0, fprz will be NULL.

Fix it by return NULL in advance.
Signed-off-by: NLiu ShuoX <shuox.liu@intel.com>
Acked-by: NKees Cook <keescook@chromium.org>
Signed-off-by: NTony Luck <tony.luck@intel.com>

In ramoops_pstore_read, a valid prz pointer with zero size buffer will
break traverse of all persistent ram buffers.  The latter buffer might be
lost.
Signed-off-by: NLiu ShuoX <shuox.liu@intel.com>
Cc: "Zhang, Yanmin" <yanmin_zhang@linux.intel.com>
Cc: Colin Cross <ccross@android.com>
Reviewed-by: NKees Cook <keescook@chromium.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NTony Luck <tony.luck@intel.com>

*_read_cnt in ramoops_context need to be cleared during pstore ->open to
support mutli times getting the records.  The patch added missed
ftrace_read_cnt clearing and removed duplicate clearing in ramoops_probe.
Signed-off-by: NLiu ShuoX <shuox.liu@intel.com>
Cc: "Zhang, Yanmin" <yanmin_zhang@linux.intel.com>
Cc: Colin Cross <ccross@android.com>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NTony Luck <tony.luck@intel.com>

Previous attempt to fix was b042e474

Suggested use of is_power_of_2() was bogus because is_power_of_2(0) is
false (documented behaviour).
Signed-off-by: NMaxime Bizon <mbizon@freebox.fr>
Acked-by: NKees Cook <keescook@chromium.org>
Signed-off-by: NTony Luck <tony.luck@intel.com>

In pstore write, add character 'C'(compressed) or 'D'(decompressed)
in the header while writing to Ram persistent buffer. In pstore read,
read the header and update the 'compressed' flag accordingly.
Signed-off-by: NAruna Balakrishnaiah <aruna@linux.vnet.ibm.com>
Reviewed-by: NKees Cook <keescook@chromium.org>
Signed-off-by: NTony Luck <tony.luck@intel.com>

Backends will set the flag 'compressed' after reading the log from
persistent store to indicate the data being returned to pstore is
compressed or not.
Signed-off-by: NAruna Balakrishnaiah <aruna@linux.vnet.ibm.com>
Reviewed-by: NKees Cook <keescook@chromium.org>
Signed-off-by: NTony Luck <tony.luck@intel.com>

Addition of new argument 'compressed' in the write call back will
help the backend to know if the data passed from pstore is compressed
or not (In case where compression fails.). If compressed, the backend
can add a tag indicating the data is compressed while writing to
persistent store.
Signed-off-by: NAruna Balakrishnaiah <aruna@linux.vnet.ibm.com>
Reviewed-by: NKees Cook <keescook@chromium.org>
Signed-off-by: NTony Luck <tony.luck@intel.com>

Header size is needed to distinguish between header and the dump data.
Incorporate the addition of new argument (hsize) in the pstore write
callback.
Signed-off-by: NAruna Balakrishnaiah <aruna@linux.vnet.ibm.com>
Acked-by: NKees Cook <keescook@chromium.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

There doesn't appear to be any reason for the overall pstore RAM buffer to
be a power of 2 size, so remove it. The individual console, ftrace and oops
buffers are still a power of 2 size.
Signed-off-by: NRob Herring <rob.herring@calxeda.com>
Acked-by: NAnton Vorontsov <anton@enomsg.org>
Signed-off-by: NTony Luck <tony.luck@intel.com>

Fix to return a negative error code from the error handling
case instead of 0, as done elsewhere in this function.
Signed-off-by: NWei Yongjun <yongjun_wei@trendmicro.com.cn>
Acked-by: NKees Cook <keescook@chromium.org>
Signed-off-by: NTony Luck <tony.luck@intel.com>

This was lost when proc/last_kmsg moved to pstore/console-ramoops.
Signed-off-by: NArve Hjønnevåg <arve@android.com>
Signed-off-by: NJohn Stultz <john.stultz@linaro.org>
Acked-by: NKees Cook <keescook@chromium.org>
Signed-off-by: NAnton Vorontsov <anton@enomsg.org>

Allow specifying ecc parameters in platform data
Signed-off-by: NArve Hjønnevåg <arve@android.com>
[jstultz: Tweaked commit subject & add commit message]
Signed-off-by: NJohn Stultz <john.stultz@linaro.org>
Acked-by: NKees Cook <keescook@chromium.org>
Signed-off-by: NAnton Vorontsov <anton@enomsg.org>