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commit 8832317f662c06f5c06e638f57bfe89a71c9b266 upstream.
Currently we do not validate rtas.entry before calling enter_rtas(). This
leads to a kernel oops when user space calls rtas system call on a powernv
platform (see below). This patch adds code to validate rtas.entry before
making enter_rtas() call.
Oops: Exception in kernel mode, sig: 4 [#1]
SMP NR_CPUS=1024 NUMA PowerNV
task: c000000004294b80 ti: c0000007e1a78000 task.ti: c0000007e1a78000
NIP: 0000000000000000 LR: 0000000000009c14 CTR: c000000000423140
REGS: c0000007e1a7b920 TRAP: 0e40 Not tainted (3.18.17-340.el7_1.pkvm3_1_0.2400.1.ppc64le)
MSR: 1000000000081000 <HV,ME> CR: 00000000 XER: 00000000
CFAR: c000000000009c0c SOFTE: 0
NIP [0000000000000000] (null)
LR [0000000000009c14] 0x9c14
Call Trace:
[c0000007e1a7bba0] [c00000000041a7f4] avc_has_perm_noaudit+0x54/0x110 (unreliable)
[c0000007e1a7bd80] [c00000000002ddc0] ppc_rtas+0x150/0x2d0
[c0000007e1a7be30] [c000000000009358] syscall_exit+0x0/0x98
Fixes: 55190f88789a ("powerpc: Add skeleton PowerNV platform")
Reported-by: NAGESWARA R. SASTRY <nasastry@in.ibm.com>
Signed-off-by: Vasant Hegde <hegdevasant@linux.vnet.ibm.com>
[mpe: Reword change log, trim oops, and add stable + fixes]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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commit 6663a4fa6711050036562ddfd2086edf735fae21 upstream.
Commit 59a53afe70fd530040bdc69581f03d880157f15a "powerpc: Don't setup
CPUs with bad status" broke ePAPR SMP booting. ePAPR says that CPUs
that aren't presently running shall have status of disabled, with
enable-method being used to determine whether the CPU can be enabled.
Fix by checking for spin-table, which is currently the only supported
enable-method.
Signed-off-by: Scott Wood <scottwood@freescale.com>
Cc: Michael Neuling <mikey@neuling.org>
Cc: Emil Medve <Emilian.Medve@Freescale.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Cc: Jonathan Toppins <jtoppins@cumulusnetworks.com>
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commit ac13282dff13cd0f4da0f0ccb134bc29bfa10255 upstream.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
[jt: fixed up context due to commit 59a53afe70fd530040bdc69581f03d880157f15a
already being backported.]
Signed-off-by: Jonathan Toppins <jtoppins@cumulusnetworks.com>
Reviewed-by: Andy Gospodarek <gospo@cumulusnetworks.com>
Acked-by: Curt Brune <curt@cumulusnetworks.com>
Acked-by: Roopa Prabhu <roopa@cumulusnetworks.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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commit 5e95235ccd5442d4a4fe11ec4eb99ba1b7959368 upstream.
Recent toolchains force the TOC to be 256 byte aligned. We need
to enforce this alignment in our linker script, otherwise pointers
to our TOC variables (__toc_start, __prom_init_toc_start) could
be incorrect.
If they are bad, we die a few hundred instructions into boot.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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commit 9a5cbce421a283e6aea3c4007f141735bf9da8c3 upstream.
We cap 32bit userspace backtraces to PERF_MAX_STACK_DEPTH
(currently 127), but we forgot to do the same for 64bit backtraces.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
[bwh: Backported to 3.2: adjust filename]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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commit f7e9e358362557c3aa2c1ec47490f29fe880a09e upstream.
This problem appears to have been introduced in 2.6.29 by commit
93197a36a9c1 "Rewrite sysfs processor cache info code".
This caused lscpu to error out on at least e500v2 devices, eg:
error: cannot open /sys/devices/system/cpu/cpu0/cache/index2/size: No such file or directory
Some embedded powerpc systems use cache-size in DTS for the unified L2
cache size, not d-cache-size, so we need to allow for both DTS names.
Added a new CACHE_TYPE_UNIFIED_D cache_type_info structure to handle
this.
Fixes: 93197a36a9c1 ("powerpc: Rewrite sysfs processor cache info code")
Signed-off-by: Dave Olson <olson@cumulusnetworks.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
[bwh: Backported to 3.2:
- Adjust context
- Preserve __cpuinit attribute on cache_do_one_devnode_unified()]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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commit 83d5e64b7efa7f39b10ff5e92792e807a720289c upstream.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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commit 59a53afe70fd530040bdc69581f03d880157f15a upstream.
OPAL will mark a CPU that is guarded as "bad" in the status property of the CPU
node.
Unfortunatley Linux doesn't check this property and will put the bad CPU in the
present map. This has caused hangs on booting when we try to unsplit the core.
This patch checks the CPU is avaliable via this status property before putting
it in the present map.
Signed-off-by: Michael Neuling <mikey@neuling.org>
Tested-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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commit c4cad90f9e9dcb85afc5e75a02ae3522ed077296 upstream.
We had a mix & match of flags used when creating legacy ports
depending on where we found them in the device-tree. Among others
we were missing UPF_SKIP_TEST for some kind of ISA ports which is
a problem as quite a few UARTs out there don't support the loopback
test (such as a lot of BMCs).
Let's pick the set of flags used by the SoC code and generalize it
which means autoconf, no loopback test, irq maybe shared and fixed
port.
Sending to stable as the lack of UPF_SKIP_TEST is breaking
serial on some machines so I want this back into distros
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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commit a5b2cf5b1af424ee3dd9e3ce6d5cea18cb927e67 upstream.
The 64bit relocation code places a few symbols in the text segment.
These symbols are only 4 byte aligned where they need to be 8 byte
aligned. Add an explicit alignment.
Signed-off-by: Anton Blanchard <anton@samba.org>
Tested-by: Laurent Dufour <ldufour@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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commit f5295bd8ea8a65dc5eac608b151386314cb978f1 upstream.
In copy_oldmem_page, the current check using max_pfn and min_low_pfn to
decide if the page is backed or not, is not valid when the memory layout is
not continuous.
This happens when running as a QEMU/KVM guest, where RTAS is mapped higher
in the memory. In that case max_pfn points to the end of RTAS, and a hole
between the end of the kdump kernel and RTAS is not backed by PTEs. As a
consequence, the kdump kernel is crashing in copy_oldmem_page when accessing
in a direct way the pages in that hole.
This fix relies on the memblock's service memblock_is_region_memory to
check if the read page is part or not of the directly accessible memory.
Signed-off-by: Laurent Dufour <ldufour@linux.vnet.ibm.com>
Tested-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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commit 91b973f90c1220d71923e7efe1e61f5329806380 upstream.
The code in remove_cache_dir() is supposed to remove the "cache"
subdirectory from the sysfs directory for a CPU when that CPU is
being offlined. It tries to do this by calling kobject_put() on
the kobject for the subdirectory. However, the subdirectory only
gets removed once the last reference goes away, and the reference
being put here may well not be the last reference. That means
that the "cache" subdirectory may still exist when the offlining
operation has finished. If the same CPU subsequently gets onlined,
the code tries to add a new "cache" subdirectory. If the old
subdirectory has not yet been removed, we get a WARN_ON in the
sysfs code, with stack trace, and an error message printed on the
console. Further, we ultimately end up with an online cpu with no
"cache" subdirectory.
This fixes it by doing an explicit kobject_del() at the point where
we want the subdirectory to go away. kobject_del() removes the sysfs
directory even though the object still exists in memory. The object
will get freed at some point in the future. A subsequent onlining
operation can create a new sysfs directory, even if the old object
still exists in memory, without causing any problems.
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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commit ec67ad82814bee92251fd963bf01c7a173856555 upstream.
In a recent patch:
commit c13f20ac48328b05cd3b8c19e31ed6c132b44b42
Author: Michael Neuling <mikey@neuling.org>
powerpc/signals: Mark VSX not saved with small contexts
We fixed an issue but an improved solution was later discussed after the patch
was merged.
Firstly, this patch doesn't handle the 64bit signals case, which could also hit
this issue (but has never been reported).
Secondly, the original patch isn't clear what MSR VSX should be set to. The
new approach below always clears the MSR VSX bit (to indicate no VSX is in the
context) and sets it only in the specific case where VSX is available (ie. when
VSX has been used and the signal context passed has space to provide the
state).
This reverts the original patch and replaces it with the improved solution. It
also adds a 64 bit version.
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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commit c13f20ac48328b05cd3b8c19e31ed6c132b44b42 upstream.
The VSX MSR bit in the user context indicates if the context contains VSX
state. Currently we set this when the process has touched VSX at any stage.
Unfortunately, if the user has not provided enough space to save the VSX state,
we can't save it but we currently still set the MSR VSX bit.
This patch changes this to clear the MSR VSX bit when the user doesn't provide
enough space. This indicates that there is no valid VSX state in the user
context.
This is needed to support get/set/make/swapcontext for applications that use
VSX but only provide a small context. For example, getcontext in glibc
provides a smaller context since the VSX registers don't need to be saved over
the glibc function call. But since the program calling getcontext may have
used VSX, the kernel currently says the VSX state is valid when it's not. If
the returned context is then used in setcontext (ie. a small context without
VSX but with MSR VSX set), the kernel will refuse the context. This situation
has been reported by the glibc community.
Based on patch from Carlos O'Donell.
Tested-by: Haren Myneni <haren@linux.vnet.ibm.com>
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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commit 84b073868b9d9e754ae48b828337633d1b386482 upstream.
When reading from the dispatch trace log (dtl) userspace interface, I
sometimes see duplicate entries. One example:
# hexdump -C dtl.out
00000000 07 04 00 0c 00 00 48 44 00 00 00 00 00 00 00 00
00000010 00 0c a0 b4 16 83 6d 68 00 00 00 00 00 00 00 00
00000020 00 00 00 00 10 00 13 50 80 00 00 00 00 00 d0 32
00000030 07 04 00 0c 00 00 48 44 00 00 00 00 00 00 00 00
00000040 00 0c a0 b4 16 83 6d 68 00 00 00 00 00 00 00 00
00000050 00 00 00 00 10 00 13 50 80 00 00 00 00 00 d0 32
The problem is in scan_dispatch_log() where we call dtl_consumer()
but bail out before incrementing the index.
To fix this I moved dtl_consumer() after the timebase comparison.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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commit 411cabf79e684171669ad29a0628c400b4431e95 upstream.
Commit e82b89a6f19bae73fb064d1b3dd91fcefbb478f4 used strcat instead of
strcpy which can result in an overflow of newlines on the buffer.
Signed-off-by: Prarit Bhargava
Cc: benh@kernel.crashing.org
Cc: ben@decadent.org.uk
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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commit e82b89a6f19bae73fb064d1b3dd91fcefbb478f4 upstream.
modalias_show() should return an empty string on error, not -ENODEV.
This causes the following false and annoying error:
> find /sys/devices -name modalias -print0 | xargs -0 cat >/dev/null
cat: /sys/devices/vio/4000/modalias: No such device
cat: /sys/devices/vio/4001/modalias: No such device
cat: /sys/devices/vio/4002/modalias: No such device
cat: /sys/devices/vio/4004/modalias: No such device
cat: /sys/devices/vio/modalias: No such device
Signed-off-by: Prarit Bhargava <prarit@redhat.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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commit 5676005acf26ab7e924a8438ea4746e47d405762 upstream.
need set '\0' for 'local_buffer'.
SPLPAR_MAXLENGTH is 1026, RTAS_DATA_BUF_SIZE is 4096. so the contents of
rtas_data_buf may truncated in memcpy.
if contents are really truncated.
the splpar_strlen is more than 1026. the next while loop checking will
not find the end of buffer. that will cause memory access violation.
Signed-off-by: Chen Gang <gang.chen@asianux.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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commit 1cf389df090194a0976dc867b7fffe99d9d490cb upstream.
Under heavy (DLPAR?) stress, we tripped this panic() in
arch/powerpc/kernel/iommu.c::iommu_init_table():
page = alloc_pages_node(nid, GFP_ATOMIC, get_order(sz));
if (!page)
panic("iommu_init_table: Can't allocate %ld bytes\n", sz);
Before the panic() we got a page allocation failure for an order-2
allocation. There appears to be memory free, but perhaps not in the
ATOMIC context. I looked through all the call-sites of
iommu_init_table() and didn't see any obvious reason to need an ATOMIC
allocation. Most call-sites in fact have an explicit GFP_KERNEL
allocation shortly before the call to iommu_init_table(), indicating we
are not in an atomic context. There is some indirection for some paths,
but I didn't see any locks indicating that GFP_KERNEL is inappropriate.
With this change under the same conditions, we have not been able to
reproduce the panic.
Signed-off-by: Nishanth Aravamudan <nacc@us.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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commit d1211af3049f4c9c1d8d4eb8f8098cc4f4f0d0c7 upstream.
arch/powerpc/kernel/sysfs.c exports PURR with write permission.
This may be valid for kernel in phyp mode. But writing to
the file in guest mode causes crash due to a priviledge violation
Signed-off-by: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
[bwh: Backported to 3.2:
- Adjust context
- CPUs are sysdev and we must use the sysdev API]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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commit 230aef7a6a23b6166bd4003bfff5af23c9bd381f upstream.
Normally when we haven't implemented an alignment handler for
a load or store instruction the process will be terminated.
The alignment handler uses the DSISR (or a pseudo one) to locate
the right handler. Unfortunately ldbrx and stdbrx overlap lfs and
stfs so we incorrectly think ldbrx is an lfs and stdbrx is an
stfs.
This bug is particularly nasty - instead of terminating the
process we apply an incorrect fixup and continue on.
With more and more overlapping instructions we should stop
creating a pseudo DSISR and index using the instruction directly,
but for now add a special case to catch ldbrx/stdbrx.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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commit f5f6cbb61610b7bf9d9d96db9c3979d62a424bab upstream.
/proc/powerpc/lparcfg is an ancient facility (though still actively used)
which allows access to some informations relative to the partition when
running underneath a PAPR compliant hypervisor.
It makes no sense on non-pseries machines. However, currently, not only
can it be created on these if the kernel has pseries support, but accessing
it on such a machine will crash due to trying to do hypervisor calls.
In fact, it should also not do HV calls on older pseries that didn't have
an hypervisor either.
Finally, it has the plumbing to be a module but is a "bool" Kconfig option.
This fixes the whole lot by turning it into a machine_device_initcall
that is only created on pseries, and adding the necessary hypervisor
check before calling the H_GET_EM_PARMS hypercall
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
[bwh: Backported to 3.2: lparcfg_cleanup() was a bit different]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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commit 0e0ed6406e61434d3f38fb58aa8464ec4722b77e upstream.
Module CRCs are implemented as absolute symbols that get resolved by
a linker script. We build an intermediate .o that contains an
unresolved symbol for each CRC. genksysms parses this .o, calculates
the CRCs and writes a linker script that "resolves" the symbols to
the calculated CRC.
Unfortunately the ppc64 relocatable kernel sees these CRCs as symbols
that need relocating and relocates them at boot. Commit d4703aef
(module: handle ppc64 relocating kcrctabs when CONFIG_RELOCATABLE=y)
added a hook to reverse the bogus relocations. Part of this patch
created a symbol at 0x0:
# head -2 /proc/kallsyms
0000000000000000 T reloc_start
c000000000000000 T .__start
This reloc_start symbol is causing lots of confusion to perf. It
thinks reloc_start is a massive function that stretches from 0x0 to
0xc000000000000000 and we get various cryptic errors out of perf,
including:
problem incrementing symbol count, skipping event
This patch removes the reloc_start linker script label and instead
defines it as PHYSICAL_START. We also need to wrap it with
CONFIG_PPC64 because the ppc32 kernel can set a non zero
PHYSICAL_START at compile time and we wouldn't want to subtract
it from the CRCs in that case.
Signed-off-by: Anton Blanchard <anton@samba.org>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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spinning_secondaries
commit 8246aca7058f3f2c2ae503081777965cd8df7b90 upstream.
the smp_release_cpus is a normal funciton and called in normal environments,
but it calls the __initdata spinning_secondaries.
need modify spinning_secondaries to match smp_release_cpus.
the related warning:
(the linker report boot_paca.33377, but it should be spinning_secondaries)
-----------------------------------------------------------------------------
WARNING: arch/powerpc/kernel/built-in.o(.text+0x23176): Section mismatch in reference from the function .smp_release_cpus() to the variable .init.data:boot_paca.33377
The function .smp_release_cpus() references
the variable __initdata boot_paca.33377.
This is often because .smp_release_cpus lacks a __initdata
annotation or the annotation of boot_paca.33377 is wrong.
WARNING: arch/powerpc/kernel/built-in.o(.text+0x231fe): Section mismatch in reference from the function .smp_release_cpus() to the variable .init.data:boot_paca.33377
The function .smp_release_cpus() references
the variable __initdata boot_paca.33377.
This is often because .smp_release_cpus lacks a __initdata
annotation or the annotation of boot_paca.33377 is wrong.
-----------------------------------------------------------------------------
Signed-off-by: Chen Gang <gang.chen@asianux.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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commit bf593907f7236e95698a76b7c7a2bbf8b1165327 upstream.
Normally, the kernel emulates a few instructions that are unimplemented
on some processors (e.g. the old dcba instruction), or privileged (e.g.
mfpvr). The emulation of unimplemented instructions is currently not
working on the PowerNV platform. The reason is that on these machines,
unimplemented and illegal instructions cause a hypervisor emulation
assist interrupt, rather than a program interrupt as on older CPUs.
Our vector for the emulation assist interrupt just calls
program_check_exception() directly, without setting the bit in SRR1
that indicates an illegal instruction interrupt. This fixes it by
making the emulation assist interrupt set that bit before calling
program_check_interrupt(). With this, old programs that use no-longer
implemented instructions such as dcba now work again.
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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commit 120496ac2d2d60aee68d3123a68169502a85f4b5 upstream.
This patch brings online all threads which are present but not online
prior to migration/hibernation. After migration/hibernation those
threads are taken back offline.
During migration/hibernation all online CPUs must call H_JOIN, this is
required by the hypervisor. Without this patch, threads that are offline
(H_CEDE'd) will not be woken to make the H_JOIN call and the OS will be
deadlocked (all threads either JOIN'd or CEDE'd).
Signed-off-by: Robert Jennings <rcj@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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commit 444080d13d05dc38d07dd3bf751d38bce7ab7c72 upstream.
This fixes a hang that was observed during live partition migration.
Since stop_topology_update must not be called from an interrupt
context, call it earlier in the migration process. The hang observed
can be seen below:
WARNING: at kernel/timer.c:1011
Modules linked in: ip6t_LOG xt_tcpudp xt_pkttype ipt_LOG xt_limit ip6t_REJECT nf_conntrack_ipv6 nf_defrag_ipv6 ip6table_raw xt_NOTRACK ipt_REJECT xt_state iptable_raw iptable_filter ip6table_mangle nf_conntrack_netbios_ns nf_conntrack_broadcast nf_conntrack_ipv4 nf_conntrack nf_defrag_ipv4 ip_tables ip6table_filter ip6_tables x_tables ipv6 fuse loop ibmveth sg ext3 jbd mbcache raid456 async_raid6_recov async_pq raid6_pq async_xor xor async_memcpy async_tx raid10 raid1 raid0 scsi_dh_alua scsi_dh_rdac scsi_dh_hp_sw scsi_dh_emc dm_round_robin dm_multipath scsi_dh sd_mod crc_t10dif ibmvfc scsi_transport_fc scsi_tgt scsi_mod dm_snapshot dm_mod
NIP: c0000000000c52d8 LR: c00000000004be28 CTR: 0000000000000000
REGS: c00000005ffd77d0 TRAP: 0700 Not tainted (3.2.0-git-00001-g07d106d)
MSR: 8000000000021032 <ME,CE,IR,DR> CR: 48000084 XER: 00000001
CFAR: c00000000004be20
TASK = c00000005ec78860[0] 'swapper/3' THREAD: c00000005ec98000 CPU: 3
GPR00: 0000000000000001 c00000005ffd7a50 c000000000fbbc98 c000000000ec8340
GPR04: 00000000282a0020 0000000000000000 0000000000004000 0000000000000101
GPR08: 0000000000000012 c00000005ffd4000 0000000000000020 c000000000f3ba88
GPR12: 0000000000000000 c000000007f40900 0000000000000001 0000000000000004
GPR16: 0000000000000001 0000000000000000 0000000000000000 c000000001022310
GPR20: 0000000000000001 0000000000000000 0000000000200200 c000000001029e14
GPR24: 0000000000000000 0000000000000001 0000000000000040 c00000003f74bc80
GPR28: c00000003f74bc84 c000000000f38038 c000000000f16b58 c000000000ec8340
NIP [c0000000000c52d8] .del_timer_sync+0x28/0x60
LR [c00000000004be28] .stop_topology_update+0x20/0x38
Call Trace:
[c00000005ffd7a50] [c00000005ec78860] 0xc00000005ec78860 (unreliable)
[c00000005ffd7ad0] [c00000000004be28] .stop_topology_update+0x20/0x38
[c00000005ffd7b40] [c000000000028378] .__rtas_suspend_last_cpu+0x58/0x260
[c00000005ffd7bf0] [c0000000000fa230] .generic_smp_call_function_interrupt+0x160/0x358
[c00000005ffd7cf0] [c000000000036ec8] .smp_ipi_demux+0x88/0x100
[c00000005ffd7d80] [c00000000005c154] .icp_hv_ipi_action+0x5c/0x80
[c00000005ffd7e00] [c00000000012a088] .handle_irq_event_percpu+0x100/0x318
[c00000005ffd7f00] [c00000000012e774] .handle_percpu_irq+0x84/0xd0
[c00000005ffd7f90] [c000000000022ba8] .call_handle_irq+0x1c/0x2c
[c00000005ec9ba20] [c00000000001157c] .do_IRQ+0x22c/0x2a8
[c00000005ec9bae0] [c0000000000054bc] hardware_interrupt_entry+0x18/0x1c
Exception: 501 at .cpu_idle+0x194/0x2f8
LR = .cpu_idle+0x194/0x2f8
[c00000005ec9bdd0] [c000000000017e58] .cpu_idle+0x188/0x2f8 (unreliable)
[c00000005ec9be90] [c00000000067ec18] .start_secondary+0x3e4/0x524
[c00000005ec9bf90] [c0000000000093e8] .start_secondary_prolog+0x10/0x14
Instruction dump:
ebe1fff8 4e800020 fbe1fff8 7c0802a6 f8010010 7c7f1b78 f821ff81 78290464
80090014 5400019e 7c0000d0 78000fe0 <0b000000> 4800000c 7c210b78 7c421378
Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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commit 29ce3c5073057991217916abc25628e906911757 upstream.
In __after_prom_start we copy the kernel down to zero in two calls to
copy_and_flush. After the first call (copy from 0 to copy_to_here:)
we jump to the newly copied code soon after.
Unfortunately there's no isync between the copy of this code and the
jump to it. Hence it's possible that stale instructions could still be
in the icache or pipeline before we branch to it.
We've seen this on real machines and it's results in no console output
after:
calling quiesce...
returning from prom_init
The below adds an isync to ensure that the copy and flushing has
completed before any branching to the new instructions occurs.
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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commit d63ac5f6cf31c8a83170a9509b350c1489a7262b upstream.
Commit 44ae3ab3358e962039c36ad4ae461ae9fb29596c forgot to update
the entry for the 970MP rev 1.0 processor when moving some CPU
features bits to the MMU feature bit mask. This breaks booting
on some rare G5 models using that chip revision.
Reported-by: Phileas Fogg <phileas-fogg@mail.ru>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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This reverts commit 066f289835f09a3f744d6bac96f25e25d20b3ded which was
6a040ce72598159a74969a2d01ab0ba5ee6536b3 upstream.
This was not needed and is not suitable for 3.2.y.
Reported-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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commit 8520e443aa56cc157b015205ea53e7b9fc831291 upstream.
Disable hard IRQ before kexec a new kernel image.
Not doing it can result in corrupted data in the memory segments
reserved for the new kernel.
Signed-off-by: Phileas Fogg <phileas-fogg@mail.ru>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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commit 6a040ce72598159a74969a2d01ab0ba5ee6536b3 upstream.
The DDW code uses a eeh_dev struct from the pci_dev. However, this is
not set until eeh_add_device_late is called.
Since pci_bus_add_devices is called before eeh_add_device_late, the PCI
devices are added to the bus, making drivers' probe hooks to be called.
These will call set_dma_mask, which will call the DDW code, which will
require the eeh_dev struct from pci_dev. This would result in a crash,
due to a NULL dereference.
Calling eeh_add_device_late after pci_bus_add_devices would make the
system BUG, because device files shouldn't be added to devices there
were not added to the system. So, a new function is needed to add such
files only after pci_bus_add_devices have been called.
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@linux.vnet.ibm.com>
Acked-by: Gavin Shan <shangw@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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commit ce73ec6db47af84d1466402781ae0872a9e7873c upstream.
The locking in update_vsyscall_tz() is not only unnecessary because the vdso
code copies the data unproteced in __kernel_gettimeofday() but also
introduces a hard to reproduce race condition between update_vsyscall()
and update_vsyscall_tz(), which causes user space process to loop
forever in vdso code.
The following patch removes the locking from update_vsyscall_tz().
Locking is not only unnecessary because the vdso code copies the data
unprotected in __kernel_gettimeofday() but also erroneous because updating
the tb_update_count is not atomic and introduces a hard to reproduce race
condition between update_vsyscall() and update_vsyscall_tz(), which further
causes user space process to loop forever in vdso code.
The below scenario describes the race condition,
x==0 Boot CPU other CPU
proc_P: x==0
timer interrupt
update_vsyscall
x==1 x++;sync settimeofday
update_vsyscall_tz
x==2 x++;sync
x==3 sync;x++
sync;x++
proc_P: x==3 (loops until x becomes even)
Because the ++ operator would be implemented as three instructions and not
atomic on powerpc.
A similar change was made for x86 in commit 6c260d58634
("x86: vdso: Remove bogus locking in update_vsyscall_tz")
Signed-off-by: Shan Hai <shan.hai@windriver.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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commit 11ee7e99f35ecb15f59b21da6a82d96d2cd3fcc8 upstream.
If we build a kernel with CONFIG_RELOCATABLE=y CONFIG_CRASH_DUMP=n,
the kernel fails when we run at a non zero offset. It turns out
we were incorrectly wrapping some of the relocatable kernel code
with CONFIG_CRASH_DUMP.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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commit 9fb1b36ca1234e64a5d1cc573175303395e3354d upstream.
We have been observing hangs, both of KVM guest vcpu tasks and more
generally, where a process that is woken doesn't properly wake up and
continue to run, but instead sticks in TASK_WAKING state. This
happens because the update of rq->wake_list in ttwu_queue_remote()
is not ordered with the update of ipi_message in
smp_muxed_ipi_message_pass(), and the reading of rq->wake_list in
scheduler_ipi() is not ordered with the reading of ipi_message in
smp_ipi_demux(). Thus it is possible for the IPI receiver not to see
the updated rq->wake_list and therefore conclude that there is nothing
for it to do.
In order to make sure that anything done before smp_send_reschedule()
is ordered before anything done in the resulting call to scheduler_ipi(),
this adds barriers in smp_muxed_message_pass() and smp_ipi_demux().
The barrier in smp_muxed_message_pass() is a full barrier to ensure that
there is a full ordering between the smp_send_reschedule() caller and
scheduler_ipi(). In smp_ipi_demux(), we use xchg() rather than
xchg_local() because xchg() includes release and acquire barriers.
Using xchg() rather than xchg_local() makes sense given that
ipi_message is not just accessed locally.
This moves the barrier between setting the message and calling the
cause_ipi() function into the individual cause_ipi implementations.
Most of them -- those that used outb, out_8 or similar -- already had
a full barrier because out_8 etc. include a sync before the MMIO
store. This adds an explicit barrier in the two remaining cases.
These changes made no measurable difference to the speed of IPIs as
measured using a simple ping-pong latency test across two CPUs on
different cores of a POWER7 machine.
The analysis of the reason why processes were not waking up properly
is due to Milton Miller.
Reported-by: Milton Miller <miltonm@bga.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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commit 714332858bfd40dcf8f741498336d93875c23aa7 upstream.
During a context switch we always restore the per thread DSCR value.
If we aren't doing explicit DSCR management
(ie thread.dscr_inherit == 0) and the default DSCR changed while
the process has been sleeping we end up with the wrong value.
Check thread.dscr_inherit and select the default DSCR or per thread
DSCR as required.
This was found with the following test case, when running with
more threads than CPUs (ie forcing context switching):
http://ozlabs.org/~anton/junkcode/dscr_default_test.c
With the four patches applied I can run a combination of all
test cases successfully at the same time:
http://ozlabs.org/~anton/junkcode/dscr_default_test.c
http://ozlabs.org/~anton/junkcode/dscr_explicit_test.c
http://ozlabs.org/~anton/junkcode/dscr_inherit_test.c
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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commit 1021cb268b3025573c4811f1dee4a11260c4507b upstream.
If the default DSCR is non zero we set thread.dscr_inherit in
copy_thread() meaning the new thread and all its children will ignore
future updates to the default DSCR. This is not intended and is
a change in behaviour that a number of our users have hit.
We just need to inherit thread.dscr and thread.dscr_inherit from
the parent which ends up being much simpler.
This was found with the following test case:
http://ozlabs.org/~anton/junkcode/dscr_default_test.c
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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commit 00ca0de02f80924dfff6b4f630e1dff3db005e35 upstream.
When we update the DSCR either via emulation of mtspr(DSCR) or via
a change to dscr_default in sysfs we don't update thread.dscr.
We will eventually update it at context switch time but there is
a period where thread.dscr is incorrect.
If we fork at this point we will copy the old value of thread.dscr
into the child. To avoid this, always keep thread.dscr in sync with
reality.
This issue was found with the following testcase:
http://ozlabs.org/~anton/junkcode/dscr_inherit_test.c
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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commit 1b6ca2a6fe56e7697d57348646e07df08f43b1bb upstream.
Writing to dscr_default in sysfs doesn't actually change the DSCR -
we rely on a context switch on each CPU to do the work. There is no
guarantee we will get a context switch in a reasonable amount of time
so fire off an IPI to force an immediate change.
This issue was found with the following test case:
http://ozlabs.org/~anton/junkcode/dscr_explicit_test.c
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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commit fd5a42980e1cf327b7240adf5e7b51ea41c23437 upstream.
Just like the module loader, ftrace needs to be updated to use r12
instead of r11 with newer gcc's.
Signed-off-by: Roger Blofeld <blofeldus@yahoo.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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commit 9f5072d4f63f28d30d343573830ac6c85fc0deff upstream.
Commit d57af9b (taskstats: use real microsecond granularity for CPU times)
renamed msecs_to_cputime to usecs_to_cputime, but failed to update all
numbers on the way. This causes nonsensical cpu idle/iowait values to be
displayed in /proc/stat (the only user of usecs_to_cputime so far).
This also renames __cputime_msec_factor to __cputime_usec_factor, adapting
its value and using it directly in cputime_to_usecs instead of doing two
multiplications.
Signed-off-by: Andreas Schwab <schwab@linux-m68k.org>
Acked-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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commit 3c75296562f43e6fbc6cddd3de948a7b3e4e9bcf upstream.
This fixes a problem which can causes kernel oopses while loading
a kernel module.
According to the PowerPC EABI specification, GPR r11 is assigned
the dedicated function to point to the previous stack frame.
In the powerpc-specific kernel module loader, do_plt_call()
(in arch/powerpc/kernel/module_32.c), GPR r11 is also used
to generate trampoline code.
This combination crashes the kernel, in the case where the compiler
chooses to use a helper function for saving GPRs on entry, and the
module loader has placed the .init.text section far away from the
.text section, meaning that it has to generate a trampoline for
functions in the .init.text section to call the GPR save helper.
Because the trampoline trashes r11, references to the stack frame
using r11 can cause an oops.
The fix just uses GPR r12 instead of GPR r11 for generating the
trampoline code. According to the statements from Freescale, this is
safe from an EABI perspective.
I've tested the fix for kernel 2.6.33 on MPC8541.
Signed-off-by: Steffen Rumler <steffen.rumler.ext@nsn.com>
[paulus@samba.org: reworded the description]
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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events
commit 9a45a9407c69d068500923480884661e2b9cc421 upstream.
perf on POWER stopped working after commit e050e3f0a71b (perf: Fix
broken interrupt rate throttling). That patch exposed a bug in
the POWER perf_events code.
Since the PMCs count upwards and take an exception when the top bit
is set, we want to write 0x80000000 - left in power_pmu_start. We were
instead programming in left which effectively disables the counter
until we eventually hit 0x80000000. This could take seconds or longer.
With the patch applied I get the expected number of samples:
SAMPLE events: 9948
Signed-off-by: Anton Blanchard <anton@samba.org>
Acked-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 37fb9a0231ee43d42d069863bdfd567fca2b61af upstream.
When re-enabling interrupts we have code to handle edge sensitive
decrementers by resetting the decrementer to 1 whenever it is negative.
If interrupts were disabled long enough that the decrementer wrapped to
positive we do nothing. This means interrupts can be delayed for a long
time until it finally goes negative again.
While we hope interrupts are never be disabled long enough for the
decrementer to go positive, we have a very good test team that can
drive any kernel into the ground. The softlockup data we get back
from these fails could be seconds in the future, completely missing
the cause of the lockup.
We already keep track of the timebase of the next event so use that
to work out if we should trigger a decrementer exception.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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On PPC64, put_sigset_t converts a sigset_t to a compat_sigset_t
before copying it to userspace. There is a typo in the case that
we have 4 words to copy, meaning that we corrupt the compat_sigset_t.
It appears that _NSIG_WORDS can't be greater than 2 at the moment
so this code is probably always optimised away anyway.
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
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With the introduction of CONFIG_PPC_ADV_DEBUG_REGS user space debug is
broken on Book-E 64-bit parts that support delayed debug events. When
switch_booke_debug_regs() sets DBCR0 we'll start getting debug events as
MSR_DE is also set and we aren't able to handle debug events from kernel
space.
We can remove the hack that always enables MSR_DE and loads up DBCR0 and
just utilize switch_booke_debug_regs() to get user space debug working
again.
We still need to handle critical/debug exception stacks & proper
save/restore of state for those exception levles to support debug events
from kernel space like we have on 32-bit.
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
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All of DebugException is already protected by CONFIG_PPC_ADV_DEBUG_REGS
there is no need to have another such ifdef inside the function.
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
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We had an existing ifdef for 4xx & BOOKE processors that got changed to
CONFIG_PPC_ADV_DEBUG_REGS. The define has nothing to do with
CONFIG_PPC_ADV_DEBUG_REGS. The define really should be:
#if defined(CONFIG_4xx) || defined(CONFIG_BOOKE)
and not
#ifdef CONFIG_PPC_ADV_DEBUG_REGS
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
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The trace_hardirqs_off will use CALLER_ADDR0 and CALLER_ADDR1.
If an exception occurs in user mode, there is only one stack frame
on the stack and accessing the CALLER_ADDR1 will causes the following
call trace. So we create a dummy stack frame to make
trace_hardirqs_off happy.
WARNING: at kernel/smp.c:459
Modules linked in:
NIP: c0093280 LR: c00930a0 CTR: c0010780
REGS: edb87ae0 TRAP: 0700 Not tainted (3.1.0)
MSR: 00021002 <ME,CE> CR: 28002888 XER: 00000000
TASK = edce2ac0[17658] 'mthread-lock-on' THREAD: edb86000 CPU: 5
GPR00: 00000001 edb87b90 edce2ac0 00000005 c0019594 edb87bd8 00000001 00000fe3
GPR08: 00041000 c084138c 4e20120d edb87b90 48002888 1001aa7c 00000000 00000000
GPR16: 48830000 10012a8c 00000000 10000af4 00000001 c0810000 00000000 00000000
GPR24: ee9aa920 c0816a18 00000000 00000005 c0019594 edb87bd8 ee20178c edb87b90
NIP [c0093280] smp_call_function_many+0x214/0x2b4
LR [c00930a0] smp_call_function_many+0x34/0x2b4
Call Trace:
[edb87b90] [c00930a0] smp_call_function_many+0x34/0x2b4 (unreliable)
[edb87bd0] [c00194ec] __flush_tlb_page+0xac/0x100
[edb87c00] [c001957c] flush_tlb_page+0x3c/0x54
[edb87c10] [c00180ac] ptep_set_access_flags+0x74/0x12c
[edb87c40] [c0128068] handle_pte_fault+0x2f0/0x9ac
[edb87cb0] [c0128c3c] handle_mm_fault+0x104/0x1dc
[edb87ce0] [c05f40f4] do_page_fault+0x2dc/0x630
[edb87e50] [c001078c] handle_page_fault+0xc/0x80
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
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kdump fails because we try to execute an HV only instruction. Feature
fixups are being applied after we copy the exception vectors down to 0
so they miss out on any updates.
We have always had this issue but it only became critical in v3.0
when we added CFAR support (breaks POWER5) and v3.1 when we added
POWERNV (breaks everyone).
Signed-off-by: Anton Blanchard <anton@samba.org>
Cc: <stable@kernel.org> [v3.0+]
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
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