By default the kernel honors the HPA (host protected area) of hard
drives. Using libata's ignore_hpa module option it's possible to
change this behaviour.
Document usage and options of libata.ignore_hpa in
Documentation/kernel-parameters.txt.
Signed-off-by: Michael Prokop <mika@grml.org>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
* 'core-fixes-for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
dma-debug: Fix the overlap() function to be correct and readable
oprofile: reset bt_lost_no_mapping with other stats
x86/oprofile: rename kernel parameter for architectural perfmon to arch_perfmon
signals: declare sys_rt_tgsigqueueinfo in syscalls.h
rcu: Mark Hierarchical RCU no longer experimental
dma-debug: Put all hash-chain locks into the same lock class
dma-debug: fix off-by-one error in overlap function
The short name of the achitecture is 'arch_perfmon'. This patch
changes the kernel parameter to use this name.
Cc: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Robert Richter <robert.richter@amd.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
* 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
x86, delay: tsc based udelay should have rdtsc_barrier
x86, setup: correct include file in <asm/boot.h>
x86, setup: Fix typo "CONFIG_x86_64" in <asm/boot.h>
x86, mce: percpu mcheck_timer should be pinned
x86: Add sysctl to allow panic on IOCK NMI error
x86: Fix uv bau sending buffer initialization
x86, mce: Fix mce resume on 32bit
x86: Move init_gbpages() to setup_arch()
x86: ensure percpu lpage doesn't consume too much vmalloc space
x86: implement percpu_alloc kernel parameter
x86: fix pageattr handling for lpage percpu allocator and re-enable it
x86: reorganize cpa_process_alias()
x86: prepare setup_pcpu_lpage() for pageattr fix
x86: rename remap percpu first chunk allocator to lpage
x86: fix duplicate free in setup_pcpu_remap() failure path
percpu: fix too lazy vunmap cache flushing
x86: Set cpu_llc_id on AMD CPUs
* 'tracing-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
ftrace: Fix the output of profile
ring-buffer: Make it generally available
ftrace: Remove duplicate newline
tracing: Fix trace_buf_size boot option
ftrace: Fix t_hash_start()
ftrace: Don't manipulate @pos in t_start()
ftrace: Don't increment @pos in g_start()
tracing: Reset iterator in t_start()
trace_stat: Don't increment @pos in seq start()
tracing_bprintk: Don't increment @pos in t_start()
tracing/events: Don't increment @pos in s_start()
This reverts commit 9e9f46c44e.
Quoting from the commit message:
"At this point, it seems to solve more problems than it causes, so let's
try using it by default. It's an easy revert if it ends up causing
trouble."
And guess what? The _CRS code causes trouble.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We should be able to specify [KMG] when setting trace_buf_size
boot option, as documented in kernel-parameters.txt
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <4A41F2DB.4020102@cn.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
* git://git.infradead.org/~dwmw2/iommu-2.6.31:
intel-iommu: Fix one last ia64 build problem in Pass Through Support
VT-d: support the device IOTLB
VT-d: cleanup iommu_flush_iotlb_psi and flush_unmaps
VT-d: add device IOTLB invalidation support
VT-d: parse ATSR in DMA Remapping Reporting Structure
PCI: handle Virtual Function ATS enabling
PCI: support the ATS capability
intel-iommu: dmar_set_interrupt return error value
intel-iommu: Tidy up iommu->gcmd handling
intel-iommu: Fix tiny theoretical race in write-buffer flush.
intel-iommu: Clean up handling of "caching mode" vs. IOTLB flushing.
intel-iommu: Clean up handling of "caching mode" vs. context flushing.
VT-d: fix invalid domain id for KVM context flush
Fix !CONFIG_DMAR build failure introduced by Intel IOMMU Pass Through Support
Intel IOMMU Pass Through Support
Fix up trivial conflicts in drivers/pci/{intel-iommu.c,intr_remapping.c}
* git://git.infradead.org/mtd-2.6: (63 commits)
mtd: OneNAND: Allow setting of boundary information when built as module
jffs2: leaking jffs2_summary in function jffs2_scan_medium
mtd: nand: Fix memory leak on txx9ndfmc probe failure.
mtd: orion_nand: use burst reads with double word accesses
mtd/nand: s3c6400 support for s3c2410 driver
[MTD] [NAND] S3C2410: Use DIV_ROUND_UP
[MTD] [NAND] S3C2410: Deal with unaligned lengths in S3C2440 buffer read/write
[MTD] [NAND] S3C2410: Allow the machine code to get the BBT table from NAND
[MTD] [NAND] S3C2410: Added a kerneldoc for s3c2410_nand_set
mtd: physmap_of: Add multiple regions and concatenation support
mtd: nand: max_retries off by one in mxc_nand
mtd: nand: s3c2410_nand_setrate(): use correct macros for 2412/2440
mtd: onenand: add bbt_wait & unlock_all as replaceable for some platform
mtd: Flex-OneNAND support
mtd: nand: add OMAP2/OMAP3 NAND driver
mtd: maps: Blackfin async: fix memory leaks in probe/remove funcs
mtd: uclinux: mark local stuff static
mtd: uclinux: do not allow to be built as a module
mtd: uclinux: allow systems to override map addr/size
mtd: blackfin NFC: fix hang when using NAND on BF527-EZKITs
...
* 'devel' of master.kernel.org:/home/rmk/linux-2.6-arm: (49 commits)
[ARM] idle: clean up pm_idle calling, obey hlt_counter
[ARM] S3C: Fix gpio-config off-by-one bug
[ARM] S3C64XX: add to_irq() support for EINT() GPIO
[ARM] S3C64XX: clock.c: fix typo in usb-host clock ctrlbit
[ARM] S3C64XX: fix HCLK gate defines
[ARM] Update mach-types
[ARM] wire up rt_tgsigqueueinfo and perf_counter_open
OMAP2 clock/powerdomain: off by 1 error in loop timeout comparisons
OMAP3 SDRC: set FIXEDDELAY when disabling SDRC DLL
OMAP3: Add support for DPLL3 divisor values higher than 2
OMAP3 SRAM: convert SRAM code to use macros rather than magic numbers
OMAP3 SRAM: add more comments on the SRAM code
OMAP3 clock/SDRC: program SDRC_MR register during SDRC clock change
OMAP3 clock: add a short delay when lowering CORE clk rate
OMAP3 clock: initialize SDRC timings at kernel start
OMAP3 clock: remove wait for DPLL3 M2 clock to stabilize
[ARM] Add old Feroceon support to compressed/head.S
[ARM] 5559/1: Limit the stack unwinding caused by a kthread exit
[ARM] 5558/1: Add extra checks to ARM unwinder to avoid tracing corrupt stacks
[ARM] 5557/1: Discard some ARM.ex*.*exit.text sections when !HOTPLUG or !HOTPLUG_CPU
...
* 'linux-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci-2.6: (74 commits)
PCI: make msi_free_irqs() to use msix_mask_irq() instead of open coded write
PCI: Fix the NIU MSI-X problem in a better way
PCI ASPM: remove get_root_port_link
PCI ASPM: cleanup pcie_aspm_sanity_check
PCI ASPM: remove has_switch field
PCI ASPM: cleanup calc_Lx_latency
PCI ASPM: cleanup pcie_aspm_get_cap_device
PCI ASPM: cleanup clkpm checks
PCI ASPM: cleanup __pcie_aspm_check_state_one
PCI ASPM: cleanup initialization
PCI ASPM: cleanup change input argument of aspm functions
PCI ASPM: cleanup misc in struct pcie_link_state
PCI ASPM: cleanup clkpm state in struct pcie_link_state
PCI ASPM: cleanup latency field in struct pcie_link_state
PCI ASPM: cleanup aspm state field in struct pcie_link_state
PCI ASPM: fix typo in struct pcie_link_state
PCI: drivers/pci/slot.c should depend on CONFIG_SYSFS
PCI: remove redundant __msi_set_enable()
PCI PM: consistently use type bool for wake enable variable
x86/ACPI: Correct maximum allowed _CRS returned resources and warn if exceeded
...
According to Andi, it isn't clear whether lpage allocator is worth the
trouble as there are many processors where PMD TLB is far scarcer than
PTE TLB. The advantage or disadvantage probably depends on the actual
size of percpu area and specific processor. As performance
degradation due to TLB pressure tends to be highly workload specific
and subtle, it is difficult to decide which way to go without more
data.
This patch implements percpu_alloc kernel parameter to allow selecting
which first chunk allocator to use to ease debugging and testing.
While at it, make sure all the failure paths report why something
failed to help determining why certain allocator isn't working. Also,
kill the "Great future plan" comment which had already been realized
quite some time ago.
[ Impact: allow explicit percpu first chunk allocator selection ]
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Jan Beulich <JBeulich@novell.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Ingo Molnar <mingo@elte.hu>
Enable the use of GCC's coverage testing tool gcov [1] with the Linux
kernel. gcov may be useful for:
* debugging (has this code been reached at all?)
* test improvement (how do I change my test to cover these lines?)
* minimizing kernel configurations (do I need this option if the
associated code is never run?)
The profiling patch incorporates the following changes:
* change kbuild to include profiling flags
* provide functions needed by profiling code
* present profiling data as files in debugfs
Note that on some architectures, enabling gcc's profiling option
"-fprofile-arcs" for the entire kernel may trigger compile/link/
run-time problems, some of which are caused by toolchain bugs and
others which require adjustment of architecture code.
For this reason profiling the entire kernel is initially restricted
to those architectures for which it is known to work without changes.
This restriction can be lifted once an architecture has been tested
and found compatible with gcc's profiling. Profiling of single files
or directories is still available on all platforms (see config help
text).
[1] http://gcc.gnu.org/onlinedocs/gcc/Gcov.html
Signed-off-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Li Wei <W.Li@Sun.COM>
Cc: Michael Ellerman <michaele@au1.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Heiko Carstens <heicars2@linux.vnet.ibm.com>
Cc: Martin Schwidefsky <mschwid2@linux.vnet.ibm.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: WANG Cong <xiyou.wangcong@gmail.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The console blank timer is currently hardcoded to 10*60 seconds which
might be annoying on systems with no input devices attached to wake up the
console again. Especially during development, disabling the screen saver
can be handy - for example when debugging the root fs mount mechanism or
other scenarios where no userspace program could be started to do that at
runtime from userspace.
This patch defines a core_param for the variable in charge which allows
users to entirely disable the blank feature at boot time by setting it 0.
The value can still be overwritten at runtime using the standard ioctl
call - this just allows to conditionally change the default.
Signed-off-by: Daniel Mack <daniel@caiaq.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Also explains why the touchscreen support is not present,
and were to find a working one...
Signed-off-by: Michel Pollet <buserror@gmail.com>
[ben-linux@fluff.org: Fix header description]
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
* 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc: (103 commits)
powerpc: Fix bug in move of altivec code to vector.S
powerpc: Add support for swiotlb on 32-bit
powerpc/spufs: Remove unused error path
powerpc: Fix warning when printing a resource_size_t
powerpc/xmon: Remove unused variable in xmon.c
powerpc/pseries: Fix warnings when printing resource_size_t
powerpc: Shield code specific to 64-bit server processors
powerpc: Separate PACA fields for server CPUs
powerpc: Split exception handling out of head_64.S
powerpc: Introduce CONFIG_PPC_BOOK3S
powerpc: Move VMX and VSX asm code to vector.S
powerpc: Set init_bootmem_done on NUMA platforms as well
powerpc/mm: Fix a AB->BA deadlock scenario with nohash MMU context lock
powerpc/mm: Fix some SMP issues with MMU context handling
powerpc: Add PTRACE_SINGLEBLOCK support
fbdev: Add PLB support and cleanup DCR in xilinxfb driver.
powerpc/virtex: Add ml510 reference design device tree
powerpc/virtex: Add Xilinx ML510 reference design support
powerpc/virtex: refactor intc driver and add support for i8259 cascading
powerpc/virtex: Add support for Xilinx PCI host bridge
...
* 'for-2.6.31' of git://git.kernel.org/pub/scm/linux/kernel/git/bart/ide-2.6: (29 commits)
ide: re-implement ide_pci_init_one() on top of ide_pci_init_two()
ide: unexport ide_find_dma_mode()
ide: fix PowerMac bootup oops
ide: skip probe if there are no devices on the port (v2)
sl82c105: add printk() logging facility
ide-tape: fix proc warning
ide: add IDE_DFLAG_NIEN_QUIRK device flag
ide: respect quirk_drives[] list on all controllers
hpt366: enable all quirks for devices on quirk_drives[] list
hpt366: sync quirk_drives[] list with pdc202xx_{new,old}.c
ide: remove superfluous SELECT_MASK() call from do_rw_taskfile()
ide: remove superfluous SELECT_MASK() call from ide_driveid_update()
icside: remove superfluous ->maskproc method
ide-tape: fix IDE_AFLAG_* atomic accesses
ide-tape: change IDE_AFLAG_IGNORE_DSC non-atomically
pdc202xx_old: kill resetproc() method
pdc202xx_old: don't call pdc202xx_reset() on IRQ timeout
pdc202xx_old: use ide_dma_test_irq()
ide: preserve Host Protected Area by default (v2)
ide-gd: implement block device ->set_capacity method (v2)
...
* 'for-linus' of git://linux-arm.org/linux-2.6:
kmemleak: Add the corresponding MAINTAINERS entry
kmemleak: Simple testing module for kmemleak
kmemleak: Enable the building of the memory leak detector
kmemleak: Remove some of the kmemleak false positives
kmemleak: Add modules support
kmemleak: Add kmemleak_alloc callback from alloc_large_system_hash
kmemleak: Add the vmalloc memory allocation/freeing hooks
kmemleak: Add the slub memory allocation/freeing hooks
kmemleak: Add the slob memory allocation/freeing hooks
kmemleak: Add the slab memory allocation/freeing hooks
kmemleak: Add documentation on the memory leak detector
kmemleak: Add the base support
Manual conflict resolution (with the slab/earlyboot changes) in:
drivers/char/vt.c
init/main.c
mm/slab.c
Adds support for PCI Express transaction layer end-to-end CRC checking
(ECRC). This patch will enable/disable ECRC checking by setting/clearing
the ECRC Check Enable and/or ECRC Generation Enable bits for devices that
support ECRC.
The ECRC setting is controlled by the "pci=ecrc=<policy>" command-line
option. If this option is not set or is set to 'bios", the enable and
generation bits are left in whatever state that firmware/BIOS set them to.
The "off" setting turns them off, and the "on" option turns them on (if the
device supports it).
Turning ECRC on or off can be a data integrity versus performance
tradeoff. In theory, turning it on will catch more data errors, turning
it off means possibly better performance since CRC does not need to be
calculated by the PCIe hardware and packet sizes are reduced.
Signed-off-by: Andrew Patterson <andrew.patterson@hp.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
At this point, it seems to solve more problems than it causes, so let's try using it by default. It's an easy revert if it ends up causing trouble.
Reviewed-by: Yinghai Lu <yhlu.kernel@gmail.com>
Acked-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
This patch adds the Documentation/kmemleak.txt file with some
information about how kmemleak works.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
* 'tracing-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (244 commits)
Revert "x86, bts: reenable ptrace branch trace support"
tracing: do not translate event helper macros in print format
ftrace/documentation: fix typo in function grapher name
tracing/events: convert block trace points to TRACE_EVENT(), fix !CONFIG_BLOCK
tracing: add protection around module events unload
tracing: add trace_seq_vprint interface
tracing: fix the block trace points print size
tracing/events: convert block trace points to TRACE_EVENT()
ring-buffer: fix ret in rb_add_time_stamp
ring-buffer: pass in lockdep class key for reader_lock
tracing: add annotation to what type of stack trace is recorded
tracing: fix multiple use of __print_flags and __print_symbolic
tracing/events: fix output format of user stack
tracing/events: fix output format of kernel stack
tracing/trace_stack: fix the number of entries in the header
ring-buffer: discard timestamps that are at the start of the buffer
ring-buffer: try to discard unneeded timestamps
ring-buffer: fix bug in ring_buffer_discard_commit
ftrace: do not profile functions when disabled
tracing: make trace pipe recognize latency format flag
...
* 'oprofile-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
oprofile: introduce module_param oprofile.cpu_type
oprofile: add support for Core i7 and Atom
oprofile: remove undocumented oprofile.p4force option
oprofile: re-add force_arch_perfmon option
* 'iommu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (61 commits)
amd-iommu: remove unnecessary "AMD IOMMU: " prefix
amd-iommu: detach device explicitly before attaching it to a new domain
amd-iommu: remove BUS_NOTIFY_BOUND_DRIVER handling
dma-debug: simplify logic in driver_filter()
dma-debug: disable/enable irqs only once in device_dma_allocations
dma-debug: use pr_* instead of printk(KERN_* ...)
dma-debug: code style fixes
dma-debug: comment style fixes
dma-debug: change hash_bucket_find from first-fit to best-fit
x86: enable GART-IOMMU only after setting up protection methods
amd_iommu: fix lock imbalance
dma-debug: add documentation for the driver filter
dma-debug: add dma_debug_driver kernel command line
dma-debug: add debugfs file for driver filter
dma-debug: add variables and checks for driver filter
dma-debug: fix debug_dma_sync_sg_for_cpu and debug_dma_sync_sg_for_device
dma-debug: use sg_dma_len accessor
dma-debug: use sg_dma_address accessor instead of using dma_address directly
amd-iommu: don't free dma adresses below 512MB with CONFIG_IOMMU_STRESS
amd-iommu: don't preallocate page tables with CONFIG_IOMMU_STRESS
...
From the perspective of most users of recent systems, disabling Host
Protected Area (HPA) can break vendor RAID formats, GPT partitions and
risks corrupting firmware or overwriting vendor system recovery tools.
Unfortunately the original (kernels < 2.6.30) behavior (unconditionally
disabling HPA and using full disk capacity) was introduced at the time
when the main use of HPA was to make the drive look small enough for the
BIOS to allow the system to boot with large capacity drives.
Thus to allow the maximum compatibility with the existing setups (using
HPA and partitioned with HPA disabled) we automically disable HPA if
any partitions overlapping HPA are detected. Additionally HPA can also
be disabled using the "nohpa" module parameter (i.e. "ide_core.nohpa=0.0"
to disable HPA on /dev/hda).
v2:
Fix ->resume HPA support.
While at it:
- remove stale "idebus=" entry from Documentation/kernel-parameters.txt
Cc: Robert Hancock <hancockrwd@gmail.com>
Cc: Frans Pop <elendil@planet.nl>
Cc: "Andries E. Brouwer" <Andries.Brouwer@cwi.nl>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Acked-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
[patch description was based on input from Alan Cox and Frans Pop]
Emphatically-Acked-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Merge reason: This branch was on an -rc5 base so pull almost-2.6.30
to resync with the latest upstream fixes and make sure
the combination works fine.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Add support for Samsung Flex-OneNAND devices.
Flex-OneNAND combines SLC and MLC technologies into a single device.
SLC area provides increased reliability and speed, suitable for storing
code such as bootloader, kernel and root file system. MLC area
provides high density and is suitable for storing user data.
SLC and MLC regions can be configured through kernel parameter.
[akpm@linux-foundation.org: export flexoand_region and onenand_addr]
Signed-off-by: Rohit Hagargundgi <h.rohit@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Cc: Vishak G <vishak.g@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
When using ftrace=function on the command line to trace functions
on boot up, one can not filter out functions that are commonly called.
This patch adds two new ftrace command line commands.
ftrace_notrace=function-list
ftrace_filter=function-list
Where function-list is a comma separated list of functions to filter.
The ftrace_notrace will make the functions listed not be included
in the function tracing, and ftrace_filter will only trace the functions
listed.
These two act the same as the debugfs/tracing/set_ftrace_notrace and
debugfs/tracing/set_ftrace_filter respectively.
The simple glob expressions that are allowed by the filter files can also
be used by the command line interface.
ftrace_notrace=rcu*,*lock,*spin*
Will not trace any function that starts with rcu, ends with lock, or has
the word spin in it.
Note, if the self tests are enabled, they may interfere with the filtering
set by the command lines.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Conflicts:
arch/mips/sibyte/bcm1480/irq.c
arch/mips/sibyte/sb1250/irq.c
Merge reason: we gathered a few conflicts plus update to latest upstream fixes.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
The kmemtrace.enable kernel parameter no longer works. To enable
kmemtrace at boot-time, you must pass "ftrace=kmemtrace" instead.
[ Impact: remove obsolete kernel parameter documentation ]
Cc: Eduard - Gabriel Munteanu <eduard.munteanu@linux360.ro>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
LKML-Reference: <alpine.DEB.2.00.0905241112190.10296@rocky>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Introduce "noxsave" boot parameter which will disable the cpu's xsave/xrstor
capabilities. Useful for debugging and working around xsave related issues.
[ Impact: make it possible to debug problems in the field ]
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
The IMA TCB policy is dangerous. A normal use can use all of a system's
memory (which cannot be freed) simply by building and running lots of
executables. The TCB policy is also nearly useless because logging in as root
often causes a policy violation when dealing with utmp, thus rendering the
measurements meaningless.
There is no good fix for this in the kernel. A full TCB policy would need to
be loaded in userspace using LSM rule matching to get both a protected and
useful system. But, if too little is measured before userspace can load a real
policy one again ends up with a meaningless set of measurements. One option
would be to put the policy load inside the initrd in order to get it early
enough in the boot sequence to be useful, but this runs into trouble with the
LSM. For IMA to measure the LSM policy and the LSM policy loading mechanism
it needs rules to do so, but we already talked about problems with defaulting
to such broad rules....
IMA also depends on the files being measured to be on an FS which implements
and supports i_version. Since the only FS with this support (ext4) doesn't
even use it by default it seems silly to have any IMA rules by default.
This should reduce the performance overhead of IMA to near 0 while still
letting users who choose to configure their machine as such to inclue the
ima_tcb kernel paramenter and get measurements during boot before they can
load a customized, reasonable policy in userspace.
Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by: Mimi Zohar <zohar@us.ibm.com>
Signed-off-by: James Morris <jmorris@namei.org>
Adds support for the "unused" page hint which can be used in shared
memory partitions to flag pages not in use, which will then be stolen
before active pages by the hypervisor when memory needs to be moved to
LPARs in need of additional memory. Failure to mark pages as 'unused'
makes the LPAR slower to give up unused memory to other partitions.
This adds the kernel parameter 'cmo_free_hint' to disable this
functionality.
Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: Robert Jennings <rcj@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Michael Prokop