When we migrate an interrupt from one CPU to another, we set the
move_in_progress flag and clean up the vectors later once they're not
being used. If you're unlucky and call destroy_irq() before the vectors
become un-used, the move_in_progress flag is never cleared, which causes
the interrupt to become unusable.
This was discovered by Jesse Brandeburg for whom it manifested as an
MSI-X device refusing to use MSI-X mode when the driver was unloaded
and reloaded repeatedly.
Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Annotate xsave_cntxt_init() as "can be called outside of __init".
Signed-off-by: Rakib Mullick <rakib.mullick@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: fix incorrect __init annotation
This patch removes the following section mismatch warning. A patch set
was send previously (http://lkml.org/lkml/2008/11/10/407). But
introduce some other problem, reported by Rufus
(http://lkml.org/lkml/2008/11/11/46). Then Ingo Molnar suggest that,
it's best to remove __init from xsave_cntxt_init(void). Which is the
second patch in this series. Now, this one removes the following
warning.
WARNING: arch/x86/kernel/built-in.o(.cpuinit.text+0x2237): Section
mismatch in reference from the function cpu_init() to the function
.init.text:init_thread_xstate()
The function __cpuinit cpu_init() references
a function __init init_thread_xstate().
If init_thread_xstate is only used by cpu_init then
annotate init_thread_xstate with a matching annotation.
Signed-off-by: Rakib Mullick <rakib.mullick@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Dell Optiplex 330 appears to hang on reboot. This is resolved by adding
a quirk to set bios reboot.
Signed-off-by: Leann Ogasawara <leann.ogasawara@canonical.com>
Signed-off-by: Steve Conklin <steve.conklin@canonical.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: widen the reach of the low-memory-protect DMI quirk
Phoenix BIOSes variously identify their vendor as "Phoenix Technologies,
LTD" or "Phoenix Technologies LTD" (without the comma.)
This patch makes the identification string in the bad_bios_dmi_table
more general (following a suggestion by Ingo Molnar), so that both
versions are handled.
Again, the patched file compiles cleanly and the patch has been tested
successfully on my machine.
Signed-off-by: Philipp Kohlbecher <xt28@gmx.de>
Cc: <stable@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: makes device isolation the default for AMD IOMMU
Some device drivers showed double-free bugs of DMA memory while testing
them with AMD IOMMU. If all devices share the same protection domain
this can lead to data corruption and data loss. Prevent this by putting
each device into its own protection domain per default.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
this compiler warning:
arch/x86/kernel/ds.c: In function 'ds_request':
arch/x86/kernel/ds.c:368: warning: 'context' may be used uninitialized in this function
Shows that the code flow in ds_request() is buggy - it goes into
the unlock+release-context path even when the context is not allocated
yet.
First allocate the context, then do the other checks.
Also, take care with GFP allocations under the ds_lock spinlock.
Cc: <stable@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: fix incorrectly marked unstable TSC clock
Patch (commit 0d12cdd "sched: improve sched_clock() performance") has
a regression on one of the test systems here.
With the patch, I see:
checking TSC synchronization [CPU#0 -> CPU#1]:
Measured 28 cycles TSC warp between CPUs, turning off TSC clock.
Marking TSC unstable due to check_tsc_sync_source failed
Whereas, without the patch syncs pass fine on all CPUs:
checking TSC synchronization [CPU#0 -> CPU#1]: passed.
Due to this, TSC is marked unstable, when it is not actually unstable.
This is because syncs in check_tsc_wrap() goes away due to this commit.
As per the discussion on this thread, correct way to fix this is to add
explicit syncs as below?
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: fix es7000 build
CC arch/x86/kernel/es7000_32.o
arch/x86/kernel/es7000_32.c: In function find_unisys_acpi_oem_table:
arch/x86/kernel/es7000_32.c:255: error: implicit declaration of function acpi_get_table_with_size
arch/x86/kernel/es7000_32.c:261: error: implicit declaration of function early_acpi_os_unmap_memory
arch/x86/kernel/es7000_32.c: In function unmap_unisys_acpi_oem_table:
arch/x86/kernel/es7000_32.c:277: error: implicit declaration of function __acpi_unmap_table
make[1]: *** [arch/x86/kernel/es7000_32.o] Error 1
we applied one patch out of order...
| commit a73aaedd95
| Author: Yinghai Lu <yhlu.kernel@gmail.com>
| Date: Sun Sep 14 02:33:14 2008 -0700
|
| x86: check dsdt before find oem table for es7000, v2
|
| v2: use __acpi_unmap_table()
that patch need:
x86: use early_ioremap in __acpi_map_table
x86: always explicitly map acpi memory
acpi: remove final __acpi_map_table mapping before setting acpi_gbl_permanent_mmap
acpi/x86: introduce __apci_map_table, v4
submitted to the ACPI tree but not upstream yet.
fix it until those patches applied, need to revert this one
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Fix a problem where ds_request() returned an error without releasing the
ds lock.
Reported-by: Stephane Eranian <eranian@gmail.com>
Signed-off-by: Markus Metzger <markus.t.metzger@gmail.com>
Cc: <stable@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This reverts commit e51af66308, which was
wrongly hoovered up and submitted about a month after a better fix had
already been merged.
The better fix is commit cbda1ba898
("PCI/iommu: blacklist DMAR on Intel G31/G33 chipsets"), where we do
this blacklisting based on the DMI identification for the offending
motherboard, since sometimes this chipset (or at least a chipset with
the same PCI ID) apparently _does_ actually have an IOMMU.
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'kvm-updates/2.6.28' of git://git.kernel.org/pub/scm/linux/kernel/git/avi/kvm:
KVM: Fix pit memory leak if unable to allocate irq source id
KVM: ia64: fix vmm_spin_{un}lock for !CONFIG_SMP
KVM: VMX: Set IGMT bit in EPT entry
KVM: Require the PCI subsystem
x86: KVM guest: fix section mismatch warning in kvmclock.c
KVM: ia64: Use guest signal mask when blocking
KVM: MMU: increase per-vcpu rmap cache alloc size
* 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux-acpi-2.6: (47 commits)
ACPI: pci_link: remove acpi_irq_balance_set() interface
fujitsu-laptop: Add DMI callback for Lifebook S6420
ACPI: EC: Don't do transaction from GPE handler in poll mode.
ACPI: EC: lower interrupt storm treshold
ACPICA: Use spinlock for acpi_{en|dis}able_gpe
ACPI: EC: restart failed command
ACPI: EC: wait for last write gpe
ACPI: EC: make kernel messages more useful when GPE storm is detected
ACPI: EC: revert msleep patch
thinkpad_acpi: fingers off backlight if video.ko is serving this functionality
sony-laptop: fingers off backlight if video.ko is serving this functionality
msi-laptop: fingers off backlight if video.ko is serving this functionality
fujitsu-laptop: fingers off backlight if video.ko is serving this functionality
eeepc-laptop: fingers off backlight if video.ko is serving this functionality
compal: fingers off backlight if video.ko is serving this functionality
asus-acpi: fingers off backlight if video.ko is serving this functionality
Acer-WMI: fingers off backlight if video.ko is serving this functionality
ACPI video: if no ACPI backlight support, use vendor drivers
ACPI: video: Ignore devices that aren't present in hardware
Delete an unwanted return statement at evgpe.c
...
This removes the acpi_irq_balance_set() interface from the PCI
interrupt link driver.
x86 used acpi_irq_balance_set() to tell the PCI interrupt link
driver to configure links to minimize IRQ sharing. But the link
driver can easily figure out whether to turn on IRQ balancing
based on the IRQ model (PIC/IOAPIC/etc), so we can get rid of
that external interface.
It's better for the driver to figure this out at init-time. If
we set it externally via the x86 code, the interface reduces
modularity, and we depend on the fact that acpi_process_madt()
happens before we process the kernel command line.
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Len Brown <len.brown@intel.com>
WARNING: arch/x86/kernel/built-in.o(.text+0x1722c): Section mismatch
in reference from the function kvm_setup_secondary_clock() to the
function .devinit.text:setup_secondary_APIC_clock()
The function kvm_setup_secondary_clock() references
the function __devinit setup_secondary_APIC_clock().
This is often because kvm_setup_secondary_clock lacks a __devinit
annotation or the annotation of setup_secondary_APIC_clock is wrong.
Signed-off-by: Md.Rakib H. Mullick <rakib.mullick@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Avi Kivity <avi@redhat.com>
Some functions that may be called from this handler require that
interrupts are disabled. Also, combining IRQF_DISABLED and
IRQF_SHARED does not reliably disable interrupts in a handler, so
remove IRQF_SHARED from the irq flags (this irq is not shared anyway).
Signed-off-by: Matt Fleming <mjf@gentoo.org>
Cc: mingo@elte.hu
Cc: venkatesh.pallipadi@intel.com
Cc: "Will Newton" <will.newton@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
In hpet_next_event() we check that the value we just wrote to
HPET_Tn_CMP(timer) has reached the chip. Currently, we're checking that
the value we wrote to HPET_Tn_CMP(timer) is in HPET_T0_CMP, which, if
timer is anything other than timer 0, is likely to fail.
Signed-off-by: Matt Fleming <mjf@gentoo.org>
Cc: mingo@elte.hu
Cc: venkatesh.pallipadi@intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
It is possible to flood the console with call traces if the WARN_ON
condition is true because of the frequency with which this function is
called.
Signed-off-by: Matt Fleming <mjf@gentoo.org>
Cc: mingo@elte.hu
Cc: venkatesh.pallipadi@intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
sched_clock() uses cycles_2_ns() needlessly - which is an irq-disabling
variant of __cycles_2_ns().
Most of the time sched_clock() is called with irqs disabled already.
The few places that call it with irqs enabled need to be updated.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This reverts commit c7ffa6c262.
the assumptio of this change was that this would not break
any existing machine. Andrey Borzenkov reported troubles with
the ACPI reboot method: the system would hang on reboot, necessiating
a power cycle. Probably more systems are affected as well.
Also, there are patches queued up for v2.6.29 to disable virtualization
on emergency_restart() - which was the original motivation of
this change.
Reported-by: Andrey Borzenkov <arvidjaar@mail.ru>
Bisected-by: Andrey Borzenkov <arvidjaar@mail.ru>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Acked-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Lazy flushing needs to take care of the unmap path too which is not yet
implemented and leads to stale IO/TLB entries. This is fixed by this
patch.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Impact: fix rare x2apic hang
On x86, x2apic mode accesses for sending IPI's don't have serializing
semantics. If the IPI receivner refers(in lock-free fashion) to some
memory setup by the sender, the need for smp_mb() before sending the
IPI becomes critical in x2apic mode.
Add the smp_mb() in native_flush_tlb_others() before sending the IPI.
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: fix boot hang on 32-bit systems with more than 224 IO-APIC pins
On some 32-bit systems with a lot of IO-APICs probe_nr_irqs() can
return a value larger than NR_IRQS. This will lead to probe_irq_on()
overrunning the irq_desc array.
I hit this when running net-next-2.6 (close to 2.6.28-rc3) on a
Supermicro dual Xeon system. NR_IRQS is 224 but probe_nr_irqs() detects
5 IOAPICs and returns 240. Here are the log messages:
Tue Nov 4 16:53:47 2008 ACPI: IOAPIC (id[0x01] address[0xfec00000] gsi_base[0])
Tue Nov 4 16:53:47 2008 IOAPIC[0]: apic_id 1, version 32, address 0xfec00000, GSI 0-23
Tue Nov 4 16:53:47 2008 ACPI: IOAPIC (id[0x02] address[0xfec81000] gsi_base[24])
Tue Nov 4 16:53:47 2008 IOAPIC[1]: apic_id 2, version 32, address 0xfec81000, GSI 24-47
Tue Nov 4 16:53:47 2008 ACPI: IOAPIC (id[0x03] address[0xfec81400] gsi_base[48])
Tue Nov 4 16:53:47 2008 IOAPIC[2]: apic_id 3, version 32, address 0xfec81400, GSI 48-71
Tue Nov 4 16:53:47 2008 ACPI: IOAPIC (id[0x04] address[0xfec82000] gsi_base[72])
Tue Nov 4 16:53:47 2008 IOAPIC[3]: apic_id 4, version 32, address 0xfec82000, GSI 72-95
Tue Nov 4 16:53:47 2008 ACPI: IOAPIC (id[0x05] address[0xfec82400] gsi_base[96])
Tue Nov 4 16:53:47 2008 IOAPIC[4]: apic_id 5, version 32, address 0xfec82400, GSI 96-119
Tue Nov 4 16:53:47 2008 ACPI: INT_SRC_OVR (bus 0 bus_irq 0 global_irq 2 high edge)
Tue Nov 4 16:53:47 2008 ACPI: INT_SRC_OVR (bus 0 bus_irq 9 global_irq 9 high level)
Tue Nov 4 16:53:47 2008 Enabling APIC mode: Flat. Using 5 I/O APICs
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Acked-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: fix udelay when "notsc" boot parameter is passed
With notsc passed on commandline, tsc may not be used for
udelays, make sure that we do not use tsc_khz to calculate
the lpj value in such cases.
Reported-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Signed-off-by: Alok N Kataria <akataria@vmware.com>
Cc: <stable@kernel.org>
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: fix AMDC1E and XTOPOLOGY conflict in cpufeature
x86: build fix
This makes the late e820 resources use 'insert_resource_expand_to_fit()'
instead of doing a 'reserve_region_with_split()', and also avoids
marking them as IORESOURCE_BUSY.
This results in us being perfectly happy to use pre-existing PCI
resources even if they were marked as being in a reserved region, while
still avoiding any _new_ allocations in the reserved regions. It also
makes for a simpler and more accurate resource tree.
Example resource allocation from Jonathan Corbet, who has firmware that
has an e820 reserved entry that covered a big range (e0000000-fed003ff),
and that had various PCI resources in it set up by firmware.
With old kernels, the reserved range would force us to re-allocate all
pre-existing PCI resources, and his reserved range would end up looking
like this:
e0000000-fed003ff : reserved
fec00000-fec00fff : IOAPIC 0
fed00000-fed003ff : HPET 0
where only the pre-allocated special regions (IOAPIC and HPET) were kept
around.
With 2.6.28-rc2, which uses 'reserve_region_with_split()', Jonathan's
resource tree looked like this:
e0000000-fe7fffff : reserved
fe800000-fe8fffff : PCI Bus 0000:01
fe800000-fe8fffff : reserved
fe900000-fe9d9aff : reserved
fe9d9b00-fe9d9bff : 0000:00:1f.3
fe9d9b00-fe9d9bff : reserved
fe9d9c00-fe9d9fff : 0000:00:1a.7
fe9d9c00-fe9d9fff : reserved
fe9da000-fe9dafff : 0000:00:03.3
fe9da000-fe9dafff : reserved
fe9db000-fe9dbfff : 0000:00:19.0
fe9db000-fe9dbfff : reserved
fe9dc000-fe9dffff : 0000:00:1b.0
fe9dc000-fe9dffff : reserved
fe9e0000-fe9fffff : 0000:00:19.0
fe9e0000-fe9fffff : reserved
fea00000-fea7ffff : 0000:00:02.0
fea00000-fea7ffff : reserved
fea80000-feafffff : 0000:00:02.1
fea80000-feafffff : reserved
feb00000-febfffff : 0000:00:02.0
feb00000-febfffff : reserved
fec00000-fed003ff : reserved
fec00000-fec00fff : IOAPIC 0
fed00000-fed003ff : HPET 0
and because the reserved entry had been split and moved into the
individual resources, and because it used the IORESOURCE_BUSY flag, the
drivers that actually wanted to _use_ those resources couldn't actually
attach to them:
e1000e 0000:00:19.0: BAR 0: can't reserve mem region [0xfe9e0000-0xfe9fffff]
HDA Intel 0000:00:1b.0: BAR 0: can't reserve mem region [0xfe9dc000-0xfe9dffff]
with this patch, the resource tree instead becomes
e0000000-fed003ff : reserved
fe800000-fe8fffff : PCI Bus 0000:01
fe9d9b00-fe9d9bff : 0000:00:1f.3
fe9d9c00-fe9d9fff : 0000:00:1a.7
fe9d9c00-fe9d9fff : ehci_hcd
fe9da000-fe9dafff : 0000:00:03.3
fe9db000-fe9dbfff : 0000:00:19.0
fe9db000-fe9dbfff : e1000e
fe9dc000-fe9dffff : 0000:00:1b.0
fe9dc000-fe9dffff : ICH HD audio
fe9e0000-fe9fffff : 0000:00:19.0
fe9e0000-fe9fffff : e1000e
fea00000-fea7ffff : 0000:00:02.0
fea80000-feafffff : 0000:00:02.1
feb00000-febfffff : 0000:00:02.0
fec00000-fec00fff : IOAPIC 0
fed00000-fed003ff : HPET 0
ie the one reserved region now ends up surrounding all the PCI resources
that were allocated inside of it by firmware, and because it is not
marked BUSY, drivers have no problem attaching to the pre-allocated
resources.
Reported-and-tested-by: Jonathan Corbet <corbet@lwn.net>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Robert Hancock <hancockr@shaw.ca>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Impact: build fix on certain UP configs
fix:
arch/x86/kernel/cpu/common.c: In function 'cpu_init':
arch/x86/kernel/cpu/common.c:1141: error: 'boot_cpu_id' undeclared (first use in this function)
arch/x86/kernel/cpu/common.c:1141: error: (Each undeclared identifier is reported only once
arch/x86/kernel/cpu/common.c:1141: error: for each function it appears in.)
Pull in asm/smp.h on UP, so that we get the definition of
boot_cpu_id.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
fix:
arch/x86/kernel/cpu/common.c: In function 'early_identify_cpu':
arch/x86/kernel/cpu/common.c:553: error: 'struct cpuinfo_x86' has no member named 'cpu_index'
as cpu_index is only available on SMP.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: fix /proc/cpuinfo output on x86/Voyager
Ever since
| commit 92cb7612ae
| Author: Mike Travis <travis@sgi.com>
| Date: Fri Oct 19 20:35:04 2007 +0200
|
| x86: convert cpuinfo_x86 array to a per_cpu array
We've had an extra field in cpuinfo_x86 which is cpu_index.
Unfortunately, voyager has never initialised this, although the only
noticeable impact seems to be that /proc/cpuinfo shows all zeros for
the processor ids.
Anyway, fix this by initialising the boot CPU properly and setting the
index when the secondaries update.
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: build fix on x86/Voyager
Given commits like this:
| Author: Suresh Siddha <suresh.b.siddha@intel.com>
| Date: Tue Jul 29 10:29:19 2008 -0700
|
| x86, xsave: enable xsave/xrstor on cpus with xsave support
Which deliberately expose boot cpu dependence to pieces of the system,
I think it's time to explicitly have a variable for it to prevent this
continual misassumption that the boot CPU is zero.
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: fix x86/Voyager boot
CONFIG_SMP is used for features which work on *all* x86 boxes.
CONFIG_X86_SMP is used for standard PC like x86 boxes (for things like
multi core and apics)
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
* 'tracing-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (31 commits)
ftrace: fix current_tracer error return
tracing: fix a build error on alpha
ftrace: use a real variable for ftrace_nop in x86
tracing/ftrace: make boot tracer select the sched_switch tracer
tracepoint: check if the probe has been registered
asm-generic: define DIE_OOPS in asm-generic
trace: fix printk warning for u64
ftrace: warning in kernel/trace/ftrace.c
ftrace: fix build failure
ftrace, powerpc, sparc64, x86: remove notrace from arch ftrace file
ftrace: remove ftrace hash
ftrace: remove mcount set
ftrace: remove daemon
ftrace: disable dynamic ftrace for all archs that use daemon
ftrace: add ftrace warn on to disable ftrace
ftrace: only have ftrace_kill atomic
ftrace: use probe_kernel
ftrace: comment arch ftrace code
ftrace: return error on failed modified text.
ftrace: dynamic ftrace process only text section
...
* 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
lockdep: fix irqs on/off ip tracing
lockdep: minor fix for debug_show_all_locks()
x86: restore the old swiotlb alloc_coherent behavior
x86: use GFP_DMA for 24bit coherent_dma_mask
swiotlb: remove panic for alloc_coherent failure
xen: compilation fix of drivers/xen/events.c on IA64
xen: portability clean up and some minor clean up for xencomm.c
xen: don't reload cr3 on suspend
kernel/resource: fix reserve_region_with_split() section mismatch
printk: remove unused code from kernel/printk.c
Impact: fix AMD Family 11h boot hangs / USB device problems
The AMD Fam11h CPUs have a K8 northbridge. This northbridge is different
from other family's because it lacks GART support (as I just learned).
But the kernel implicitly expects a GART if it finds an AMD northbridge.
Fix this by removing the Fam11h northbridge id from the scan list of K8
northbridges. This patch also changes the message in the GART driver
about missing K8 northbridges to tell that the GART is missing which is
the correct information in this case.
Reported-by: Jouni Malinen <jkmalinen@gmail.com>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: fix kdump crash on 32-bit sparsemem kernels
Since linux-2.6.27, kdump has failed on i386 sparsemem kernel.
1st-kernel gets a panic just before switching to 2nd-kernel.
The cause is that a kernel accesses invalid mem_section by
page_to_pfn(image->swap_page) at machine_kexec().
image->swap_page is allocated if kexec for hibernation, but
it is not allocated if kdump. So if kdump, a kernel should
not access the mem_section corresponding to image->swap_page.
The attached patch fixes this invalid access.
Signed-off-by: Ken'ichi Ohmichi <oomichi@mxs.nes.nec.co.jp>
Cc: kexec-ml <kexec@lists.infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: avoid section mismatch warning, clean up
The dynamic ftrace determines which nop is safe to use at start up.
When it finds a safe nop for patching, it sets a pointer called ftrace_nop
to point to the code. All call sites are then patched to this nop.
Later, when tracing is turned on, this ftrace_nop variable is again used
to compare the location to make sure it is a nop before we update it to
an mcount call. If this fails just once, a warning is printed and ftrace
is disabled.
Rakib Mullick noted that the code that sets up the nop is a .init section
where as the nop itself is in the .text section. This is needed because
the nop is used later on after boot up. The problem is that the test of the
nop jumps back to the setup code and causes a "section mismatch" warning.
Rakib first recommended to convert the nop to .init.text, but as stated
above, this would fail since that text is used later.
The real solution is to extend Rabik's patch, and to make the ftrace_nop
into an array, and just save the code from the assembly to this array.
Now the section can stay as an init section, and we have a nop to use
later on.
Reported-by: Rakib Mullick <rakib.mullick@gmail.com>
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
