Seiji Aguchi [Wed, 14 Nov 2012 20:28:18 +0000 (20:28 +0000)]
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
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>
Seiji Aguchi [Wed, 14 Nov 2012 20:27:28 +0000 (20:27 +0000)]
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
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>
Seiji Aguchi [Wed, 14 Nov 2012 20:26:46 +0000 (20:26 +0000)]
efi_pstore: Remove a logic erasing entries from a write callback to hold multiple logs
[Issue]
Currently, efi_pstore driver simply overwrites existing panic messages in NVRAM.
So, in the following scenario, we will lose 1st panic messages.
1. kernel panics.
2. efi_pstore is kicked and writes panic messages to NVRAM.
3. system reboots.
4. kernel panics again before a user checks the 1st panic messages in NVRAM.
[Solution]
A reasonable solution to fix the issue is just holding multiple logs without erasing
existing entries.
This patch removes a logic erasing existing entries in a write callback
because the logic is not needed in the write callback to support holding multiple logs.
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>
Seiji Aguchi [Wed, 14 Nov 2012 20:26:21 +0000 (20:26 +0000)]
efi_pstore: Add a logic erasing entries to an erase callback
[Issue]
Currently, efi_pstore driver simply overwrites existing panic messages in NVRAM.
So, in the following scenario, we will lose 1st panic messages.
1. kernel panics.
2. efi_pstore is kicked and writes panic messages to NVRAM.
3. system reboots.
4. kernel panics again before a user checks the 1st panic messages in NVRAM.
[Solution]
A reasonable solution to fix the issue is just holding multiple logs without erasing
existing entries.
This patch freshly adds a logic erasing existing entries, which shared with a write callback,
to an erase callback.
To support holding multiple logs, the write callback doesn't need to erase any entries and
it will be removed in a subsequent patch.
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>
Seiji Aguchi [Wed, 14 Nov 2012 20:25:37 +0000 (20:25 +0000)]
efi_pstore: Check remaining space with QueryVariableInfo() before writing data
[Issue]
As discussed in a thread below, Running out of space in EFI isn't a well-tested scenario.
And we wouldn't expect all firmware to handle it gracefully.
http://marc.info/?l=linux-kernel&m=134305325801789&w=2
On the other hand, current efi_pstore doesn't check a remaining space of storage at writing time.
Therefore, efi_pstore may not work if it tries to write a large amount of data.
[Patch Description]
To avoid handling the situation above, this patch checks if there is a space enough to log with
QueryVariableInfo() before writing data.
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>
Linus Torvalds [Wed, 14 Nov 2012 21:46:40 +0000 (13:46 -0800)]
Merge branch 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux
Pull power tools fixes from Len Brown:
"A pair of power tools patches -- a 3.7 regression fix plus a bug fix."
* 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux:
tools/power turbostat: graceful fail on garbage input
tools/power turbostat: Repair Segmentation fault when using -i option
Linus Torvalds [Wed, 14 Nov 2012 21:45:23 +0000 (13:45 -0800)]
Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus
Pull MIPS update from Ralf Baechle:
"To avoid unnecessary risk and work the preemption fixes are combined
with some preparatory work that isn't strictly required. So it's
really just 3 fixes:
- Get is_compat_task() to do the right thing while simplifying it.
The unnecessary complexity hid a rarely striking bug which could be
triggered by ext3/ext4 under certain circumstances.
- Resolve a preemption issue in the irqflags.h functions for kernels
built to support pre-MIPS32 / pre-MIPS64 Release 2 processors.
- Fix the interrupt number of the MIPS Malta's CBUS UART."
* 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus:
MIPS: Malta: Fix interupt number of CBUS UART.
MIPS: Make irqflags.h functions preempt-safe for non-mipsr2 cpus
MIPS: Remove irqflags.h dependency from bitops.h
MIPS: bitops.h: Change use of 'unsigned short' to 'int'
MIPS: compat: Delete now unused TIF_32BIT.
MIPS: compat: Implement is_compat_task() by testing for 32-bit address space.
MIPS: compat: Fix use of TIF_32BIT_ADDR vs _TIF_32BIT_ADDR
Linus Torvalds [Wed, 14 Nov 2012 21:44:04 +0000 (13:44 -0800)]
Merge branch 'for-3.7-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
Pull cgroup fixes from Tejun Heo:
"This contains two fix patches for device_cgroup. One fixes a
regression introduced earlier in 3.7 cycle where device_cgroup could
try to dereference the NULL parent of the root cgroup. The other one
is RCU usage fix."
projects / karo-tx-linux.git / log