When (hot)adding memory into system, /sys/firmware/memmap/X/{end, start,
type} sysfs files are created. But there is no code to remove these
files. This patch implements the function to remove them.
We cannot free firmware_map_entry which is allocated by bootmem because
there is no way to do so when the system is up. But we can at least
remember the address of that memory and reuse the storage when the
memory is added next time.
This patch also introduces a new list map_entries_bootmem to link the
map entries allocated by bootmem when they are removed, and a lock to
protect it. And these entries will be reused when the memory is
hot-added again.
The idea is suggestted by Andrew Morton.
NOTE: It is unsafe to return an entry pointer and release the
map_entries_lock. So we should not hold the map_entries_lock
separately in firmware_map_find_entry() and
firmware_map_remove_entry(). Hold the map_entries_lock across find
and remove /sys/firmware/memmap/X operation.
And also, users of these two functions need to be careful to
hold the lock when using these two functions.
[tangchen@cn.fujitsu.com: Hold spinlock across find|remove /sys operation]
[tangchen@cn.fujitsu.com: fix the wrong comments of map_entries]
[tangchen@cn.fujitsu.com: reuse the storage of /sys/firmware/memmap/X/ allocated by bootmem]
[tangchen@cn.fujitsu.com: fix section mismatch problem]
[tangchen@cn.fujitsu.com: fix the doc format in drivers/firmware/memmap.c]
Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
Signed-off-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Signed-off-by: Tang Chen <tangchen@cn.fujitsu.com>
Reviewed-by: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Jiang Liu <jiang.liu@huawei.com>
Cc: Jianguo Wu <wujianguo@huawei.com>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Tang Chen <tangchen@cn.fujitsu.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Julian Calaby <julian.calaby@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
a system in the crash path. Plus a new mountpoint
(/sys/fs/pstore ... makes more sense then /dev/pstore).
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Merge tag 'please-pull-pstore' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux
Pull pstore patches from Tony Luck:
"A few fixes to reduce places where pstore might hang a system in the
crash path. Plus a new mountpoint (/sys/fs/pstore ... makes more
sense then /dev/pstore)."
Fix up trivial conflict in drivers/firmware/efivars.c
* tag 'please-pull-pstore' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux:
pstore: Create a convenient mount point for pstore
efi_pstore: Introducing workqueue updating sysfs
efivars: Disable external interrupt while holding efivars->lock
efi_pstore: Avoid deadlock in non-blocking paths
pstore: Avoid deadlock in panic and emergency-restart path
[Problem]
efi_pstore creates sysfs entries, which enable users to access to NVRAM,
in a write callback. If a kernel panic happens in an interrupt context,
it may fail because it could sleep due to dynamic memory allocations during
creating sysfs entries.
[Patch Description]
This patch removes sysfs operations from a write callback by introducing
a workqueue updating sysfs entries which is scheduled after the write
callback is called.
Also, the workqueue is kicked in a just oops case.
A system will go down in other cases such as panic, clean shutdown and emergency
restart. And we don't need to create sysfs entries because there is no chance for
users to access to them.
efi_pstore will be robust against a kernel panic in an interrupt context with this patch.
Signed-off-by: Seiji Aguchi <seiji.aguchi@hds.com>
Acked-by: Matt Fleming <matt.fleming@intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
[Problem]
There is a scenario which efi_pstore fails to log messages in a panic case.
- CPUA holds an efi_var->lock in either efivarfs parts
or efi_pstore with interrupt enabled.
- CPUB panics and sends IPI to CPUA in smp_send_stop().
- CPUA stops with holding the lock.
- CPUB kicks efi_pstore_write() via kmsg_dump(KSMG_DUMP_PANIC)
but it returns without logging messages.
[Patch Description]
This patch disables an external interruption while holding efivars->lock
as follows.
In efi_pstore_write() and get_var_data(), spin_lock/spin_unlock is
replaced by spin_lock_irqsave/spin_unlock_irqrestore because they may
be called in an interrupt context.
In other functions, they are replaced by spin_lock_irq/spin_unlock_irq.
because they are all called from a process context.
By applying this patch, we can avoid the problem above with
a following senario.
- CPUA holds an efi_var->lock with interrupt disabled.
- CPUB panics and sends IPI to CPUA in smp_send_stop().
- CPUA receives the IPI after releasing the lock because it is
disabling interrupt while holding the lock.
- CPUB waits for one sec until CPUA releases the lock.
- CPUB kicks efi_pstore_write() via kmsg_dump(KSMG_DUMP_PANIC)
And it can hold the lock successfully.
Signed-off-by: Seiji Aguchi <seiji.aguchi@hds.com>
Acked-by: Mike Waychison <mikew@google.com>
Acked-by: Matt Fleming <matt.fleming@intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Pull x86 EFI fixes from Peter Anvin:
"This is a collection of fixes for the EFI support. The controversial
bit here is a set of patches which bumps the boot protocol version as
part of fixing some serious problems with the EFI handover protocol,
used when booting under EFI using a bootloader as opposed to directly
from EFI. These changes should also make it a lot saner to support
cross-mode 32/64-bit EFI booting in the future. Getting these changes
into 3.8 means we avoid presenting an inconsistent ABI to bootloaders.
Other changes are display detection and fixing efivarfs."
* 'x86-efi-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86, efi: remove attribute check from setup_efi_pci
x86, build: Dynamically find entry points in compressed startup code
x86, efi: Fix PCI ROM handing in EFI boot stub, in 32-bit mode
x86, efi: Fix 32-bit EFI handover protocol entry point
x86, efi: Fix display detection in EFI boot stub
x86, boot: Define the 2.12 bzImage boot protocol
x86/boot: Fix minor fd leakage in tools/relocs.c
x86, efi: Set runtime_version to the EFI spec revision
x86, efi: fix 32-bit warnings in setup_efi_pci()
efivarfs: Delete dentry from dcache in efivarfs_file_write()
efivarfs: Never return ENOENT from firmware
efi, x86: Pass a proper identity mapping in efi_call_phys_prelog
efivarfs: Drop link count of the right inode
Originally 'efi_enabled' indicated whether a kernel was booted from
EFI firmware. Over time its semantics have changed, and it now
indicates whether or not we are booted on an EFI machine with
bit-native firmware, e.g. 64-bit kernel with 64-bit firmware.
The immediate motivation for this patch is the bug report at,
https://bugs.launchpad.net/ubuntu-cdimage/+bug/1040557
which details how running a platform driver on an EFI machine that is
designed to run under BIOS can cause the machine to become
bricked. Also, the following report,
https://bugzilla.kernel.org/show_bug.cgi?id=47121
details how running said driver can also cause Machine Check
Exceptions. Drivers need a new means of detecting whether they're
running on an EFI machine, as sadly the expression,
if (!efi_enabled)
hasn't been a sufficient condition for quite some time.
Users actually want to query 'efi_enabled' for different reasons -
what they really want access to is the list of available EFI
facilities.
For instance, the x86 reboot code needs to know whether it can invoke
the ResetSystem() function provided by the EFI runtime services, while
the ACPI OSL code wants to know whether the EFI config tables were
mapped successfully. There are also checks in some of the platform
driver code to simply see if they're running on an EFI machine (which
would make it a bad idea to do BIOS-y things).
This patch is a prereq for the samsung-laptop fix patch.
Cc: David Airlie <airlied@linux.ie>
Cc: Corentin Chary <corentincj@iksaif.net>
Cc: Matthew Garrett <mjg59@srcf.ucam.org>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Olof Johansson <olof@lixom.net>
Cc: Peter Jones <pjones@redhat.com>
Cc: Colin Ian King <colin.king@canonical.com>
Cc: Steve Langasek <steve.langasek@canonical.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Konrad Rzeszutek Wilk <konrad@kernel.org>
Cc: Rafael J. Wysocki <rjw@sisk.pl>
Cc: <stable@vger.kernel.org>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Files are created in efivarfs_create() before a corresponding variable
is created in the firmware. This leads to users being able to
read/write to the file without the variable existing in the
firmware. Reading a non-existent variable currently returns -ENOENT,
which is confusing because the file obviously *does* exist.
Convert EFI_NOT_FOUND into -EIO which is the closest thing to "error
while interacting with firmware", and should hopefully indicate to the
caller that the variable is in some uninitialised state.
Cc: Josh Boyer <jwboyer@redhat.com>
Acked-by: Jeremy Kerr <jeremy.kerr@canonical.com>
Cc: Lee, Chun-Yi <jlee@suse.com>
Cc: Andy Whitcroft <apw@canonical.com>
Reported-by: Lingzhu Xiang <lxiang@redhat.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
efivarfs_unlink() should drop the file's link count, not the directory's.
Signed-off-by: Lingzhu Xiang <lxiang@redhat.com>
Cc: Jeremy Kerr <jeremy.kerr@canonical.com>
Tested-by: Lee, Chun-Yi <jlee@suse.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
[Issue]
There is a scenario which efi_pstore may hang up:
- cpuA grabs efivars->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 efivars->lock
- cpuB is deadlocked
This case may happen if a firmware has a bug and
cpuA is stuck talking with it.
[Solution]
This patch changes a spin_lock to a spin_trylock in non-blocking paths.
and if the spin_lock has already taken by another cpu,
it returns without accessing to a firmware to avoid the deadlock.
Signed-off-by: Seiji Aguchi <seiji.aguchi@hds.com>
Acked-by: Don Zickus <dzickus@redhat.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
CONFIG_HOTPLUG is going away as an option. As a result, the __dev*
markings need to be removed.
This change removes the use of __devinit, __devexit_p, __devinitdata,
__devinitconst, and __devexit from these drivers.
Based on patches originally written by Bill Pemberton, but redone by me
in order to handle some of the coding style issues better, by hand.
Cc: Bill Pemberton <wfp5p@virginia.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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 <zhenzhong.duan@oracle.com>
Cc: Feng Jin <joe.jin@oracle.com>
Cc: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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 <zhenzhong.duan@oracle.com>
Cc: Feng Jin <joe.jin@oracle.com>
Cc: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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" <ebiederm@xmission.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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
...
[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 <seiji.aguchi@hds.com>
Acked-by: Mike Waychison <mikew@google.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
[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 <seiji.aguchi@hds.com>
Acked-by: Mike Waychison <mikew@google.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
[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>
[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>
[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>
[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>
[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>
sparse is complaining that efivarfs_fill_super() doesn't have a
prototype. Make it static to avoid the warning.
Cc: Xie ChanglongX <changlongx.xie@intel.com>
Cc: Matthew Garrett <mjg@redhat.com>
Cc: Jeremy Kerr <jeremy.kerr@canonical.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
We don't want someone who can write EFI variables to be able to
allocate arbitrarily large amounts of memory, so cap it to something
sensible like the amount of free space for EFI variables.
Acked-by: Jeremy Kerr <jeremy.kerr@canonical.com>
Cc: Matthew Garrett <mjg@redhat.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
We're stuffing a variable of type size_t (unsigned) into a ssize_t
(signed) which, even though both types should be the same number of
bits, it's just asking for sign issues to be introduced.
Cc: Jeremy Kerr <jeremy.kerr@canonical.com>
Reported-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Instead of returning -ENOSPC if efivarfs_get_inode() fails we should
be returning -ENOMEM, since running out of memory is the only reason
it can fail. Furthermore, that's the error value used everywhere else
in this file. It's also less likely to confuse users that hit this
error case.
Acked-by: Jeremy Kerr <jeremy.kerr@canonical.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
There's no reason to declare 'datasize' as an int, since the majority
of the functions it's passed to expect an unsigned long anyway. Plus,
this way we avoid any sign problems during arithmetic.
Acked-by: Jeremy Kerr <jeremy.kerr@canonical.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Using pstore's superblock magic number is no doubt going to cause
problems in the future. Give efivarfs its own magic number.
Acked-by: Jeremy Kerr <jeremy.kerr@canonical.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Seeing "+ 4" littered throughout the functions gets a bit
confusing. Use "sizeof(attributes)" which clearly explains what
quantity we're adding.
Acked-by: Jeremy Kerr <jeremy.kerr@canonical.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Instead of always returning 0 in efivarfs_file_read(), even when we
fail to successfully read the variable, convert the EFI status to
something meaningful and return that to the caller. This way the user
will have some hint as to why the read failed.
Acked-by: Jeremy Kerr <jeremy.kerr@canonical.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
At present, the handling of GUIDs in efivar file names isn't consistent.
We use GUID_LEN in some places, and 38 in others (GUID_LEN plus
separator), and implicitly use the presence of the trailing NUL.
This change removes the trailing NUL from GUID_LEN, so that we're
explicitly adding it when required. We also replace magic numbers
with GUID_LEN, and clarify the comments where appropriate.
We also fix the allocation size in efivar_create_sysfs_entry, where
we're allocating one byte too much, due to counting the trailing NUL
twice - once when calculating short_name_size, and once in the kzalloc.
Signed-off-by: Jeremy Kerr <jeremy.kerr@canonical.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Currently, efivarfs does not enforce exclusion over the get_variable and
set_variable operations. Section 7.1 of UEFI requires us to only allow a
single processor to enter {get,set}_variable services at once.
This change acquires the efivars->lock over calls to these operations
from the efivarfs paths.
Signed-off-by: Jeremy Kerr <jeremy.kerr@canonical.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Ensure we free both the name and inode on error when building the
individual variables.
Signed-off-by: Andy Whitcroft <apw@canonical.com>
Acked-by: Matthew Garrett <mjg@redhat.com>
Acked-by: Jeremy Kerr <jeremy.kerr@canonical.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
d_alloc_name() copies the passed name to new storage, once complete we
no longer need our name.
Signed-off-by: Andy Whitcroft <apw@canonical.com>
Acked-by: Matthew Garrett <mjg@redhat.com>
Acked-by: Jeremy Kerr <jeremy.kerr@canonical.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
When d_make_root() fails it will automatically drop the reference
on the root inode. We should not be doing so as well.
Signed-off-by: Andy Whitcroft <apw@canonical.com>
Acked-by: Matthew Garrett <mjg@redhat.com>
Acked-by: Jeremy Kerr <jeremy.kerr@canonical.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Signed-off-by: Andy Whitcroft <apw@canonical.com>
Acked-by: Matthew Garrett <mjg@redhat.com>
Acked-by: Jeremy Kerr <jeremy.kerr@canonical.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Signed-off-by: Andy Whitcroft <apw@canonical.com>
Acked-by: Matthew Garrett <mjg@redhat.com>
Acked-by: Jeremy Kerr <jeremy.kerr@canonical.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
UEFI variable filesystem need a new mount point, so this patch add
efivars kobject to efi_kobj for create a /sys/firmware/efi/efivars
folder.
Cc: Matthew Garrett <mjg@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Lee, Chun-Yi <jlee@suse.com>
Signed-off-by: Jeremy Kerr <jeremy.kerr@canonical.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
A write to an efivarfs file will not always result in a variable of
'count' size after the EFI SetVariable() call. We may have appended to
the existing data (ie, with the EFI_VARIABLE_APPEND_WRITE attribute), or
even have deleted the variable (with an authenticated variable update,
with a zero datasize).
This change re-reads the updated variable from firmware, to check for
size changes and deletions. In the latter case, we need to drop the
dentry.
Signed-off-by: Jeremy Kerr <jeremy.kerr@canonical.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
The existing EFI variables code only supports variables of up to 1024
bytes. This limitation existed in version 0.99 of the EFI specification,
but was removed before any full releases. Since variables can now be
larger than a single page, sysfs isn't the best interface for this. So,
instead, let's add a filesystem. Variables can be read, written and
created, with the first 4 bytes of each variable representing its UEFI
attributes. The create() method doesn't actually commit to flash since
zero-length variables can't exist per-spec.
Updates from Jeremy Kerr <jeremy.kerr@canonical.com>.
Signed-off-by: Matthew Garrett <mjg@redhat.com>
Signed-off-by: Jeremy Kerr <jeremy.kerr@canonical.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Fix this build error:
drivers/firmware/memmap.c:240:19: error: conflicting types for 'memmap_init'
arch/ia64/include/asm/pgtable.h:565:17: note: previous declaration of 'memmap_init' was here
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Cc: Bernhard Walle <bwalle@suse.de>
Cc: Glauber Costa <glommer@parallels.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Some of the EFI variable attributes are missing from print out from
/sys/firmware/efi/vars/*/attributes. This patch adds those in. It also
updates code to use pre-defined constants for masking current value
of attributes.
Signed-off-by: Khalid Aziz <khalid.aziz@hp.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Acked-by: Matthew Garrett <mjg@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
from interrupts for /dev/random and /dev/urandom. The goal is to
addresses weaknesses discussed in the paper "Mining your Ps and Qs:
Detection of Widespread Weak Keys in Network Devices", by Nadia
Heninger, Zakir Durumeric, Eric Wustrow, J. Alex Halderman, which will
be published in the Proceedings of the 21st Usenix Security Symposium,
August 2012. (See https://factorable.net for more information and an
extended version of the paper.)
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Merge tag 'random_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/random
Pull random subsystem patches from Ted Ts'o:
"This patch series contains a major revamp of how we collect entropy
from interrupts for /dev/random and /dev/urandom.
The goal is to addresses weaknesses discussed in the paper "Mining
your Ps and Qs: Detection of Widespread Weak Keys in Network Devices",
by Nadia Heninger, Zakir Durumeric, Eric Wustrow, J. Alex Halderman,
which will be published in the Proceedings of the 21st Usenix Security
Symposium, August 2012. (See https://factorable.net for more
information and an extended version of the paper.)"
Fix up trivial conflicts due to nearby changes in
drivers/{mfd/ab3100-core.c, usb/gadget/omap_udc.c}
* tag 'random_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/random: (33 commits)
random: mix in architectural randomness in extract_buf()
dmi: Feed DMI table to /dev/random driver
random: Add comment to random_initialize()
random: final removal of IRQF_SAMPLE_RANDOM
um: remove IRQF_SAMPLE_RANDOM which is now a no-op
sparc/ldc: remove IRQF_SAMPLE_RANDOM which is now a no-op
[ARM] pxa: remove IRQF_SAMPLE_RANDOM which is now a no-op
board-palmz71: remove IRQF_SAMPLE_RANDOM which is now a no-op
isp1301_omap: remove IRQF_SAMPLE_RANDOM which is now a no-op
pxa25x_udc: remove IRQF_SAMPLE_RANDOM which is now a no-op
omap_udc: remove IRQF_SAMPLE_RANDOM which is now a no-op
goku_udc: remove IRQF_SAMPLE_RANDOM which was commented out
uartlite: remove IRQF_SAMPLE_RANDOM which is now a no-op
drivers: hv: remove IRQF_SAMPLE_RANDOM which is now a no-op
xen-blkfront: remove IRQF_SAMPLE_RANDOM which is now a no-op
n2_crypto: remove IRQF_SAMPLE_RANDOM which is now a no-op
pda_power: remove IRQF_SAMPLE_RANDOM which is now a no-op
i2c-pmcmsp: remove IRQF_SAMPLE_RANDOM which is now a no-op
input/serio/hp_sdc.c: remove IRQF_SAMPLE_RANDOM which is now a no-op
mfd: remove IRQF_SAMPLE_RANDOM which is now a no-op
...
There are two ways to create /sys/firmware/memmap/X sysfs:
- firmware_map_add_early
When the system starts, it is calledd from e820_reserve_resources()
- firmware_map_add_hotplug
When the memory is hot plugged, it is called from add_memory()
But these functions are called without unifying value of end argument as
below:
- end argument of firmware_map_add_early() : start + size - 1
- end argument of firmware_map_add_hogplug() : start + size
The patch unifies them to "start + size". Even if applying the patch,
/sys/firmware/memmap/X/end file content does not change.
[akpm@linux-foundation.org: clarify comments]
Signed-off-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Reviewed-by: Dave Hansen <dave@linux.vnet.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
efi_setup_pcdp_console() is called during boot to parse the HCDP/PCDP
EFI system table and setup an early console for printk output. The
routine uses ioremap/iounmap to setup access to the HCDP/PCDP table
information.
The call to ioremap is happening early in the boot process which leads
to a panic on x86_64 systems:
panic+0x01ca
do_exit+0x043c
oops_end+0x00a7
no_context+0x0119
__bad_area_nosemaphore+0x0138
bad_area_nosemaphore+0x000e
do_page_fault+0x0321
page_fault+0x0020
reserve_memtype+0x02a1
__ioremap_caller+0x0123
ioremap_nocache+0x0012
efi_setup_pcdp_console+0x002b
setup_arch+0x03a9
start_kernel+0x00d4
x86_64_start_reservations+0x012c
x86_64_start_kernel+0x00fe
This replaces the calls to ioremap/iounmap in efi_setup_pcdp_console()
with calls to early_ioremap/early_iounmap which can be called during
early boot.
This patch was tested on an x86_64 prototype system which uses the
HCDP/PCDP table for early console setup.
Signed-off-by: Greg Pearson <greg.pearson@hp.com>
Acked-by: Khalid Aziz <khalid.aziz@hp.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Send the entire DMI (SMBIOS) table to the /dev/random driver to
help seed its pools.
Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Ben Hutchings pointed out that the validation in efivars was inadequate -
most obviously, an entry with size 0 would server as a DoS against the
kernel. Improve this based on his suggestions.
Signed-off-by: Matthew Garrett <mjg@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
A common flaw in UEFI systems is a refusal to POST triggered by a malformed
boot variable. Once in this state, machines may only be restored by
reflashing their firmware with an external hardware device. While this is
obviously a firmware bug, the serious nature of the outcome suggests that
operating systems should filter their variable writes in order to prevent
a malicious user from rendering the machine unusable.
Signed-off-by: Matthew Garrett <mjg@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound: (526 commits)
ASoC: twl6040 - Add method to query optimum PDM_DL1 gain
ALSA: hda - Fix the lost power-setup of seconary pins after PM resume
ALSA: usb-audio: add Yamaha MOX6/MOX8 support
ALSA: virtuoso: add S/PDIF input support for all Xonars
ALSA: ice1724 - Support for ooAoo SQ210a
ALSA: ice1724 - Allow card info based on model only
ALSA: ice1724 - Create capture pcm only for ADC-enabled configurations
ALSA: hdspm - Provide unique driver id based on card serial
ASoC: Dynamically allocate the rtd device for a non-empty release()
ASoC: Fix recursive dependency due to select ATMEL_SSC in SND_ATMEL_SOC_SSC
ALSA: hda - Fix the detection of "Loopback Mixing" control for VIA codecs
ALSA: hda - Return the error from get_wcaps_type() for invalid NIDs
ALSA: hda - Use auto-parser for HP laptops with cx20459 codec
ALSA: asihpi - Fix potential Oops in snd_asihpi_cmode_info()
ALSA: hdsp - Fix potential Oops in snd_hdsp_info_pref_sync_ref()
ALSA: hda/cirrus - support for iMac12,2 model
ASoC: cx20442: add bias control over a platform provided regulator
ALSA: usb-audio - Avoid flood of frame-active debug messages
ALSA: snd-usb-us122l: Delete calls to preempt_disable
mfd: Put WM8994 into cache only mode when suspending
...
Fix up trivial conflicts in:
- arch/arm/mach-s3c64xx/mach-crag6410.c:
renamed speyside_wm8962 to tobermory, added littlemill right
next to it
- drivers/base/regmap/{regcache.c,regmap.c}:
duplicate diff that had already come in with other changes in
the regmap tree
* 'for-linus2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (165 commits)
reiserfs: Properly display mount options in /proc/mounts
vfs: prevent remount read-only if pending removes
vfs: count unlinked inodes
vfs: protect remounting superblock read-only
vfs: keep list of mounts for each superblock
vfs: switch ->show_options() to struct dentry *
vfs: switch ->show_path() to struct dentry *
vfs: switch ->show_devname() to struct dentry *
vfs: switch ->show_stats to struct dentry *
switch security_path_chmod() to struct path *
vfs: prefer ->dentry->d_sb to ->mnt->mnt_sb
vfs: trim includes a bit
switch mnt_namespace ->root to struct mount
vfs: take /proc/*/mounts and friends to fs/proc_namespace.c
vfs: opencode mntget() mnt_set_mountpoint()
vfs: spread struct mount - remaining argument of next_mnt()
vfs: move fsnotify junk to struct mount
vfs: move mnt_devname
vfs: move mnt_list to struct mount
vfs: switch pnode.h macros to struct mount *
...
