user/sven/linux.git/include/linux/pstore.h, branch v4.1.15

pstore: Add pstore type id for PPC64 opal nvram partition

2015-03-23T03:06:10Z

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

2015-01-17T00:01:10Z

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

2013-12-20T21:12:01Z

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

2013-08-19T17:18:11Z

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

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

2013-08-19T17:18:10Z

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

pstore: Pass header size in the pstore write callback

2013-07-01T08:10:48Z

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 Acked-by: Kees Cook Signed-off-by: Benjamin Herrenschmidt

powerpc/pseries: Read common partition via pstore

2013-06-20T07:05:02Z

This patch exploits pstore subsystem to read details of common partition in NVRAM to a separate file in /dev/pstore. For instance, common partition details will be stored in a file named [common-nvram-6]. Signed-off-by: Aruna Balakrishnaiah Reviewed-by: Jim Keniston Signed-off-by: Benjamin Herrenschmidt

powerpc/pseries: Read of-config partition via pstore

2013-06-20T07:04:59Z

This patch set exploits the pstore subsystem to read details of of-config partition in NVRAM to a separate file in /dev/pstore. For instance, of-config partition details will be stored in a file named [of-nvram-5]. Signed-off-by: Aruna Balakrishnaiah Reviewed-by: Jim Keniston Signed-off-by: Benjamin Herrenschmidt

powerpc/pseries: Read rtas partition via pstore

2013-06-20T07:04:52Z

This patch set exploits the pstore subsystem to read details of rtas partition in NVRAM to a separate file in /dev/pstore. For instance, rtas details will be stored in a file named [rtas-nvram-4]. Signed-off-by: Aruna Balakrishnaiah Reviewed-by: Jim Keniston Signed-off-by: Benjamin Herrenschmidt

pstore: Avoid deadlock in panic and emergency-restart path

2013-01-11T18:20:50Z

[Issue] When pstore is in panic and emergency-restart paths, it may be blocked in those paths because it simply takes spin_lock. This is an example scenario which pstore may hang up in a panic path: - cpuA grabs psinfo->buf_lock - cpuB panics and calls smp_send_stop - smp_send_stop sends IRQ to cpuA - after 1 second, cpuB gives up on cpuA and sends an NMI instead - cpuA is now in an NMI handler while still holding buf_lock - cpuB is deadlocked This case may happen if a firmware has a bug and cpuA is stuck talking with it more than one second. Also, this is a similar scenario in an emergency-restart path: - cpuA grabs psinfo->buf_lock and stucks in a firmware - cpuB kicks emergency-restart via either sysrq-b or hangcheck timer. And then, cpuB is deadlocked by taking psinfo->buf_lock again. [Solution] This patch avoids the deadlocking issues in both panic and emergency_restart paths by introducing a function, is_non_blocking_path(), to check if a cpu can be blocked in current path. With this patch, pstore is not blocked even if another cpu has taken a spin_lock, in those paths by changing from spin_lock_irqsave to spin_trylock_irqsave. In addition, according to a comment of emergency_restart() in kernel/sys.c, spin_lock shouldn't be taken in an emergency_restart path to avoid deadlock. This patch fits the comment below. /** * emergency_restart - reboot the system * * Without shutting down any hardware or taking any locks * reboot the system. This is called when we know we are in * trouble so this is our best effort to reboot. This is * safe to call in interrupt context. */ void emergency_restart(void) Signed-off-by: Seiji Aguchi Acked-by: Don Zickus Signed-off-by: Tony Luck