linux.git/drivers/firmware, branch v3.8-rc2

drivers/firmware/dmi_scan.c: fetch dmi version from SMBIOS if it exists

2012-12-21T01:40:19+00:00

The right dmi version is in SMBIOS if it's zero in DMI region

This issue was originally found from an oracle bug.
One customer noticed system UUID doesn't match between dmidecode & uek2.

 - HP ProLiant BL460c G6 :
   # cat /sys/devices/virtual/dmi/id/product_uuid
   00000000-0000-4C48-3031-4D5030333531
   # dmidecode | grep -i uuid
   UUID: 00000000-0000-484C-3031-4D5030333531

From SMBIOS 2.6 on, spec use little-endian encoding for UUID other than
network byte order.

So we need to get dmi version to distinguish.  If version is 0.0, the
real version is taken from the SMBIOS version.  This is part of original
kernel comment in code.

[akpm@linux-foundation.org: checkpatch fixes]
Signed-off-by: Zhenzhong Duan 
Cc: Feng Jin 
Cc: Jean Delvare 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

drivers/firmware/dmi_scan.c: check dmi version when get system uuid

2012-12-21T01:40:19+00:00

As of version 2.6 of the SMBIOS specification, the first 3 fields of the
UUID are supposed to be little-endian encoded.

Also a minor fix to match variable meaning and mute checkpatch.pl

[akpm@linux-foundation.org: tweak code comment]
Signed-off-by: Zhenzhong Duan 
Cc: Feng Jin 
Cc: Jean Delvare 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

efi: Fix the build with user namespaces enabled.

2012-12-18T04:14:15+00:00

When compiling efivars.c the build fails with:

   CC      drivers/firmware/efivars.o
  drivers/firmware/efivars.c: In function ‘efivarfs_get_inode’:
  drivers/firmware/efivars.c:886:31: error: incompatible types when assigning to type ‘kgid_t’ from type ‘int’
  make[2]: *** [drivers/firmware/efivars.o] Error 1
  make[1]: *** [drivers/firmware/efivars.o] Error 2

Fix the build error by removing the duplicate initialization of i_uid and
i_gid inode_init_always has already initialized them to 0.

Signed-off-by: "Eric W. Biederman" 
Signed-off-by: Linus Torvalds

Merge branch 'core-efi-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2012-12-14T18:08:40+00:00

Pull x86 EFI update from Peter Anvin:
 "EFI tree, from Matt Fleming.  Most of the patches are the new efivarfs
  filesystem by Matt Garrett & co.  The balance are support for EFI
  wallclock in the absence of a hardware-specific driver, and various
  fixes and cleanups."

* 'core-efi-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (24 commits)
  efivarfs: Make efivarfs_fill_super() static
  x86, efi: Check table header length in efi_bgrt_init()
  efivarfs: Use query_variable_info() to limit kmalloc()
  efivarfs: Fix return value of efivarfs_file_write()
  efivarfs: Return a consistent error when efivarfs_get_inode() fails
  efivarfs: Make 'datasize' unsigned long
  efivarfs: Add unique magic number
  efivarfs: Replace magic number with sizeof(attributes)
  efivarfs: Return an error if we fail to read a variable
  efi: Clarify GUID length calculations
  efivarfs: Implement exclusive access for {get,set}_variable
  efivarfs: efivarfs_fill_super() ensure we clean up correctly on error
  efivarfs: efivarfs_fill_super() ensure we free our temporary name
  efivarfs: efivarfs_fill_super() fix inode reference counts
  efivarfs: efivarfs_create() ensure we drop our reference on inode on error
  efivarfs: efivarfs_file_read ensure we free data in error paths
  x86-64/efi: Use EFI to deal with platform wall clock (again)
  x86/kernel: remove tboot 1:1 page table creation code
  x86, efi: 1:1 pagetable mapping for virtual EFI calls
  x86, mm: Include the entire kernel memory map in trampoline_pgd
  ...

efi_pstore: Add a format check for an existing variable name at erasing time

2012-11-27T00:08:37+00:00

[Issue]

a format of variable name has been updated to type, id, count and ctime
to support holding multiple logs.

Format of current variable name
  dump-type0-1-2-12345678

  type:0
  id:1
  count:2
  ctime:12345678

On the other hand, if an old variable name before being updated
remains, users can't erase it via /dev/pstore.

Format of old variable name
  dump-type0-1-12345678

  type:0
  id:1
  ctime:12345678

[Solution]

This patch add a format check for the old variable name in a erase callback to make it erasable.

Signed-off-by: Seiji Aguchi 
Acked-by: Mike Waychison 
Signed-off-by: Tony Luck

efi_pstore: Add a format check for an existing variable name at reading time

2012-11-27T00:08:30+00:00

[Issue]

a format of variable name has been updated to type, id, count and ctime
to support holding multiple logs.

Format of current variable name
  dump-type0-1-2-12345678

  type:0
  id:1
  count:2
  ctime:12345678

On the other hand, if an old variable name before being updated
remains, users can't read it via /dev/pstore.

Format of old variable name
  dump-type0-1-12345678

  type:0
  id:1
  ctime:12345678

[Solution]

This patch add a format check for the old variable name in a read callback
to make it readable.

Signed-off-by: Seiji Aguchi 
Acked-by: Mike Waychison 
Signed-off-by: Tony Luck

efi_pstore: Add a sequence counter to a variable name

2012-11-27T00:07:44+00:00

[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.

  
 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.

  

 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 
Acked-by: Rafael J. Wysocki 
Acked-by: Mike Waychison 
Signed-off-by: Tony Luck

efi_pstore: Add ctime to argument of erase callback

2012-11-27T00:02:12+00:00

[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.

 

 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 
Acked-by: Mike Waychison 
Signed-off-by: Tony Luck

efi_pstore: Remove a logic erasing entries from a write callback to hold multiple logs

2012-11-27T00:02:04+00:00

[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 
Acked-by: Mike Waychison 
Signed-off-by: Tony Luck

efi_pstore: Add a logic erasing entries to an erase callback

2012-11-27T00:01:56+00:00

[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 
Acked-by: Mike Waychison 
Signed-off-by: Tony Luck