linux-toradex.git/include/linux/pstore.h, branch v4.11-rc3

pstore: Add ftrace timestamp counter

2016-11-16T00:34:27+00:00

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 
[kees: updated commit message, added comments]
Signed-off-by: Kees Cook

pstore/pmsg: drop bounce buffer

2016-09-08T22:01:10+00:00

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 
Signed-off-by: Kees Cook

pstore/ram: Set pstore flags dynamically

2016-09-08T22:01:09+00:00

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 
Cc: Colin Cross 
Cc: Kees Cook 
Cc: Tony Luck 
Signed-off-by: Namhyung Kim 
Signed-off-by: Kees Cook

pstore: Split pstore fragile flags

2016-09-08T22:01:08+00:00

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 
Cc: Colin Cross 
Cc: Kees Cook 
Cc: Tony Luck 
Cc: "Rafael J. Wysocki" 
Cc: Len Brown 
Cc: Matt Fleming 
Cc: linux-acpi@vger.kernel.org
Cc: linux-efi@vger.kernel.org
Signed-off-by: Namhyung Kim 
[kees: retained "FRAGILE" for now to make merges easier]
Signed-off-by: Kees Cook

pstore: add lzo/lz4 compression support

2016-06-02T17:59:31+00:00

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 
Signed-off-by: Kees Cook

pstore: add pstore unregister

2015-10-22T15:59:18+00:00

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 
Acked-by: Kees Cook 
[Removed __exit annotation from ramoops_remove(). Reported by Arnd Bergmann]
Signed-off-by: Tony Luck

pstore: Add pstore type id for PPC64 opal nvram partition

2015-03-23T03:06:10+00:00

This patch adds a new PPC64 partition type to be used for opal
specific nvram partition. A new partition type is needed as none
of the existing type matches this partition type.

Signed-off-by: Hari Bathini 
Reviewed-by: Kees Cook 
Signed-off-by: Michael Ellerman

pstore: Add pmsg - user-space accessible pstore object

2015-01-17T00:01:10+00:00

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: Mark Salyzyn 
Acked-by: Kees Cook 
Signed-off-by: Tony Luck

pstore: Don't allow high traffic options on fragile devices

2013-12-20T21:12:01+00:00

Some pstore backing devices use on board flash as persistent
storage. These have limited numbers of write cycles so it
is a poor idea to use them from high frequency operations.

Signed-off-by: Tony Luck 
Signed-off-by: Linus Torvalds

pstore: Introduce new argument 'compressed' in the read callback

2013-08-19T17:18:11+00:00

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: Aruna Balakrishnaiah 
Reviewed-by: Kees Cook 
Signed-off-by: Tony Luck