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

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 u

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

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 <tony.luck@intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

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erst: Read and write to the 'compressed' flag of pstore

In pstore write, set the section type to CPER_SECTION_TYPE_DMESG_COMPR
if the data is compressed. In pstore read, read the section type and
up

erst: Read and write to the 'compressed' flag of pstore

In pstore write, set the section type to CPER_SECTION_TYPE_DMESG_COMPR
if the data is compressed. In pstore read, read the section type and
update the 'compressed' flag accordingly.

Signed-off-by: Aruna Balakrishnaiah <aruna@linux.vnet.ibm.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Tony Luck <tony.luck@intel.com>

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

Backends will set the flag 'compressed' after reading the log from
persistent store to indicate the data being returned to pstore is

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

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 <aruna@linux.vnet.ibm.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Tony Luck <tony.luck@intel.com>

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pstore: Add new argument 'compressed' in pstore write callback

Addition of new argument 'compressed' in the write call back will
help the backend to know if the data passed from pstore is compressed

pstore: Add new argument 'compressed' in pstore write callback

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: Aruna Balakrishnaiah <aruna@linux.vnet.ibm.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Tony Luck <tony.luck@intel.com>

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acpi/apei/erst: Add missing iounmap() on error in erst_exec_move_data()

Add the missing iounmap() before return from erst_exec_move_data()
in the error handling case.

Signed-off-by: Wei Yongjun <yo

acpi/apei/erst: Add missing iounmap() on error in erst_exec_move_data()

Add the missing iounmap() before return from erst_exec_move_data()
in the error handling case.

Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Tony Luck <tony.luck@intel.com>

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APEI/ERST: Fix error message formatting

... according to acpi/apei/ conventions. Use standard pr_fmt prefix
while at it.

Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Bjorn Helgaas <bhelgaa

APEI/ERST: Fix error message formatting

... according to acpi/apei/ conventions. Use standard pr_fmt prefix
while at it.

Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>

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pstore: Pass header size in the pstore write callback

Header size is needed to distinguish between header and the dump data.
Incorporate the addition of new argument (hsize) in the pstore write
call

pstore: Pass header size in the pstore write callback

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: Aruna Balakrishnaiah <aruna@linux.vnet.ibm.com>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

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acpi: Eliminate console msg if pstore.backend excludes ERST

This is patch 2/3 of a patch set that avoids what misleadingly appears
to be a error during boot:

ERST: Could not register with persisten

acpi: Eliminate console msg if pstore.backend excludes ERST

This is patch 2/3 of a patch set that avoids what misleadingly appears
to be a error during boot:

ERST: Could not register with persistent store

This message is displayed if the system has a valid ACPI ERST table and the
pstore.backend kernel parameter has been used to disable use of ERST by
pstore. But this same message is used for errors that preclude registration.

In erst_init don't complain if the setting of kernel parameter pstore.backend
precludes use of ACPI ERST for pstore. Routine pstore_register will inform
about the facility that does register.

Also, don't leave a dangling pointer to deallocated mem for the pstore
buffer when registration fails.

Signed-off-by: Lenny Szubowicz <lszubowi@redhat.com>
Reported-by: Naotaka Hamaguchi <n.hamaguchi@jp.fujitsu.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>

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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

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>

show more ...

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

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>

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ACPI, APEI, Fix ERST header length check

This fixes a trivial copy & paste error in ERST header length check.
It's just for future safety because sizeof(struct acpi_table_einj)
equals to sizeof(stru

ACPI, APEI, Fix ERST header length check

This fixes a trivial copy & paste error in ERST header length check.
It's just for future safety because sizeof(struct acpi_table_einj)
equals to sizeof(struct acpi_table_erst) with current ACPI5.0
specification. It applies to v3.3-rc6.

Signed-off-by: Jiang Liu <jiang.liu@huawei.com>
Acked-by: Huang Ying <ying.huang@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

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ACPI, APEI, Remove table not found message

Because APEI tables are optional, these message may confuse users, for
example,

https://bugs.launchpad.net/ubuntu/+source/linux/+bug/599715

Reported-by:

ACPI, APEI, Remove table not found message

Because APEI tables are optional, these message may confuse users, for
example,

https://bugs.launchpad.net/ubuntu/+source/linux/+bug/599715

Reported-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Huang Ying <ying.huang@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

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pstore: pass reason to backend write callback

This allows a backend to filter on the dmesg reason as well as the pstore
reason. When ramoops is switched to pstore, this is needed since it has
no int

pstore: pass reason to backend write callback

This allows a backend to filter on the dmesg reason as well as the pstore
reason. When ramoops is switched to pstore, this is needed since it has
no interest in storing non-crash dmesg details.

Drop pstore_write() as it has no users, and handling the "reason" here
has no obviously correct value.

Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Tony Luck <tony.luck@intel.com>

show more ...

pstore: pass allocated memory region back to caller

The buf_lock cannot be held while populating the inodes, so make the backend
pass forward an allocated and filled buffer instead. This solves the

pstore: pass allocated memory region back to caller

The buf_lock cannot be held while populating the inodes, so make the backend
pass forward an allocated and filled buffer instead. This solves the following
backtrace. The effect is that "buf" is only ever used to notify the backends
that something was written to it, and shouldn't be used in the read path.

To replace the buf_lock during the read path, isolate the open/read/close
loop with a separate mutex to maintain serialized access to the backend.

Note that is is up to the pstore backend to cope if the (*write)() path is
called in the middle of the read path.

[ 59.691019] BUG: sleeping function called from invalid context at .../mm/slub.c:847
[ 59.691019] in_atomic(): 0, irqs_disabled(): 1, pid: 1819, name: mount
[ 59.691019] Pid: 1819, comm: mount Not tainted 3.0.8 #1
[ 59.691019] Call Trace:
[ 59.691019] [<810252d5>] __might_sleep+0xc3/0xca
[ 59.691019] [<810a26e6>] kmem_cache_alloc+0x32/0xf3
[ 59.691019] [<810b53ac>] ? __d_lookup_rcu+0x6f/0xf4
[ 59.691019] [<810b68b1>] alloc_inode+0x2a/0x64
[ 59.691019] [<810b6903>] new_inode+0x18/0x43
[ 59.691019] [<81142447>] pstore_get_inode.isra.1+0x11/0x98
[ 59.691019] [<81142623>] pstore_mkfile+0xae/0x26f
[ 59.691019] [<810a2a66>] ? kmem_cache_free+0x19/0xb1
[ 59.691019] [<8116c821>] ? ida_get_new_above+0x140/0x158
[ 59.691019] [<811708ea>] ? __init_rwsem+0x1e/0x2c
[ 59.691019] [<810b67e8>] ? inode_init_always+0x111/0x1b0
[ 59.691019] [<8102127e>] ? should_resched+0xd/0x27
[ 59.691019] [<8137977f>] ? _cond_resched+0xd/0x21
[ 59.691019] [<81142abf>] pstore_get_records+0x52/0xa7
[ 59.691019] [<8114254b>] pstore_fill_super+0x7d/0x91
[ 59.691019] [<810a7ff5>] mount_single+0x46/0x82
[ 59.691019] [<8114231a>] pstore_mount+0x15/0x17
[ 59.691019] [<811424ce>] ? pstore_get_inode.isra.1+0x98/0x98
[ 59.691019] [<810a8199>] mount_fs+0x5a/0x12d
[ 59.691019] [<810b9174>] ? alloc_vfsmnt+0xa4/0x14a
[ 59.691019] [<810b9474>] vfs_kern_mount+0x4f/0x7d
[ 59.691019] [<810b9d7e>] do_kern_mount+0x34/0xb2
[ 59.691019] [<810bb15f>] do_mount+0x5fc/0x64a
[ 59.691019] [<810912fb>] ? strndup_user+0x2e/0x3f
[ 59.691019] [<810bb3cb>] sys_mount+0x66/0x99
[ 59.691019] [<8137b537>] sysenter_do_call+0x12/0x26

Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Tony Luck <tony.luck@intel.com>

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pstore: make pstore write function return normal success/fail value

Currently pstore write interface employs record id as return
value, but it is not enough because it can't tell caller if
the write

pstore: make pstore write function return normal success/fail value

Currently pstore write interface employs record id as return
value, but it is not enough because it can't tell caller if
the write operation is successful. Pass the record id back via
an argument pointer and return zero for success, non-zero for
failure.

Signed-off-by: Chen Gong <gong.chen@linux.intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>

show more ...

pstore: change mutex locking to spin_locks

pstore was using mutex locking to protect read/write access to the
backend plug-ins. This causes problems when pstore is executed in
an NMI context throug

pstore: change mutex locking to spin_locks

pstore was using mutex locking to protect read/write access to the
backend plug-ins. This causes problems when pstore is executed in
an NMI context through panic() -> kmsg_dump().

This patch changes the mutex to a spin_lock_irqsave then also checks to
see if we are in an NMI context. If we are in an NMI and can't get the
lock, just print a message stating that and blow by the locking.

All this is probably a hack around the bigger locking problem but it
solves my current situation of trying to sleep in an NMI context.

Tested by loading the lkdtm module and executing a HARDLOCKUP which
will cause the machine to panic inside the nmi handler.

Signed-off-by: Don Zickus <dzickus@redhat.com>
Acked-by: Matthew Garrett <mjg@redhat.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>

show more ...

pstore: Make "part" unsigned

We'll never have a negative part, so just make this an unsigned int.

Signed-off-by: Matthew Garrett <mjg@redhat.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>

pstore: Add extra context for writes and erases

EFI only provides small amounts of individual storage, and conventionally
puts metadata in the storage variable name. Rather than add a metadata
heade

pstore: Add extra context for writes and erases

EFI only provides small amounts of individual storage, and conventionally
puts metadata in the storage variable name. Rather than add a metadata
header to the (already limited) variable storage, it's easier for us to
modify pstore to pass all the information we need to construct a unique
variable name to the appropriate functions.

Signed-off-by: Matthew Garrett <mjg@redhat.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>

show more ...

pstore: Extend API for more flexibility in new backends

Some pstore implementations may not have a static context, so extend the
API to pass the pstore_info struct to all calls and allow for a conte

pstore: Extend API for more flexibility in new backends

Some pstore implementations may not have a static context, so extend the
API to pass the pstore_info struct to all calls and allow for a context
pointer.

Signed-off-by: Matthew Garrett <mjg@redhat.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>

show more ...

ACPI, APEI, Use apei_exec_run_optional in APEI EINJ and ERST

This patch changes APEI EINJ and ERST to use apei_exec_run for
mandatory actions, and apei_exec_run_optional for optional actions.

Cc: T

ACPI, APEI, Use apei_exec_run_optional in APEI EINJ and ERST

This patch changes APEI EINJ and ERST to use apei_exec_run for
mandatory actions, and apei_exec_run_optional for optional actions.

Cc: Thomas Renninger <trenn@novell.com>
Signed-off-by: Huang Ying <ying.huang@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

show more ...

pstore: fix potential logic issue in pstore read interface

1) in the calling of erst_read, the parameter of buffer size
maybe overflows and cause crash

2) the return value of erst_read should be ch

pstore: fix potential logic issue in pstore read interface

1) in the calling of erst_read, the parameter of buffer size
maybe overflows and cause crash

2) the return value of erst_read should be checked more strictly

Signed-off-by: Chen Gong <gong.chen@linux.intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>

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pstore: fix pstore filesystem mount/remount issue

Currently after mount/remount operation on pstore filesystem,
the content on pstore will be lost. It is because current ERST
implementation doesn't

pstore: fix pstore filesystem mount/remount issue

Currently after mount/remount operation on pstore filesystem,
the content on pstore will be lost. It is because current ERST
implementation doesn't support multi-user usage, which moves
internal pointer to the end after accessing it. Adding
multi-user support for pstore usage.

Signed-off-by: Chen Gong <gong.chen@linux.intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>

show more ...

pstore: fix one type of return value in pstore

the return type of function _read_ in pstore is size_t,
but in the callback function of _read_, the logic doesn't
consider it too much, which means if

pstore: fix one type of return value in pstore

the return type of function _read_ in pstore is size_t,
but in the callback function of _read_, the logic doesn't
consider it too much, which means if negative value (assuming
error here) is returned, it will be converted to positive because
of type casting. ssize_t is enough for this function.

Signed-off-by: Chen Gong <gong.chen@linux.intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>

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ACPI, APEI, Add ERST record ID cache

APEI ERST firmware interface and implementation has no multiple users
in mind. For example, if there is four records in storage with ID: 1,
2, 3 and 4, if two E

ACPI, APEI, Add ERST record ID cache

APEI ERST firmware interface and implementation has no multiple users
in mind. For example, if there is four records in storage with ID: 1,
2, 3 and 4, if two ERST readers enumerate the records via
GET_NEXT_RECORD_ID as follow,

reader 1 reader 2
1
2
3
4
-1
-1

where -1 signals there is no more record ID.

Reader 1 has no chance to check record 2 and 4, while reader 2 has no
chance to check record 1 and 3. And any other GET_NEXT_RECORD_ID will
return -1, that is, other readers will has no chance to check any
record even they are not cleared by anyone.

This makes raw GET_NEXT_RECORD_ID not suitable for used by multiple
users.

To solve the issue, an in-memory ERST record ID cache is designed and
implemented. When enumerating record ID, the ID returned by
GET_NEXT_RECORD_ID is added into cache in addition to be returned to
caller. So other readers can check the cache to get all record ID
available.

Signed-off-by: Huang Ying <ying.huang@intel.com>
Reviewed-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

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pstore: X86 platform interface using ACPI/APEI/ERST

The 'error record serialization table' in ACPI provides a suitable
amount of persistent storage for use by the pstore filesystem.

Signed-off-by:

pstore: X86 platform interface using ACPI/APEI/ERST

The 'error record serialization table' in ACPI provides a suitable
amount of persistent storage for use by the pstore filesystem.

Signed-off-by: Tony Luck <tony.luck@intel.com>

show more ...