Pull powerpc fixes from Ben Herrenschmidt:
"A bit more endian problems found during testing of 3.13 and a few
other simple fixes and regressions fixes"
* 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc:
powerpc: Fix alignment of secondary cpu spin vars
powerpc: Align p_end
powernv/eeh: Add buffer for P7IOC hub error data
powernv/eeh: Fix possible buffer overrun in ioda_eeh_phb_diag()
powerpc: Make 64-bit non-VMX __copy_tofrom_user bi-endian
powerpc: Make unaligned accesses endian-safe for powerpc
powerpc: Fix bad stack check in exception entry
powerpc/512x: dts: disable MPC5125 usb module
powerpc/512x: dts: remove misplaced IRQ spec from 'soc' node (5125)
Commit 5c0484e25e ('powerpc: Endian safe trampoline') resulted in
losing proper alignment of the spinlock variables used when booting
secondary CPUs, causing some quite odd issues with failing to boot on
PA Semi-based systems.
This showed itself on ppc64_defconfig, but not on pasemi_defconfig,
so it had gone unnoticed when I initially tested the LE patch set.
Fix is to add explicit alignment instead of relying on good luck. :)
[ It appears that there is a different issue with PA Semi systems
however this fix is definitely correct so applying anyway -- BenH
]
Fixes: 5c0484e25e ('powerpc: Endian safe trampoline')
Reported-by: Christian Zigotzky <chzigotzky@xenosoft.de>
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=67811
Signed-off-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
p_end is an 8 byte value embedded in the text section. This means it
is only 4 byte aligned when it should be 8 byte aligned. Fix this
by adding an explicit alignment.
This fixes an issue where POWER7 little endian builds with
CONFIG_RELOCATABLE=y fail to boot.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Prevent ioda_eeh_hub_diag() from clobbering itself when called by supplying
a per-PHB buffer for P7IOC hub diagnostic data. Take care to inform OPAL of
the correct size for the buffer.
[Small style change to the use of sizeof -- BenH]
Signed-off-by: Brian W Hart <hartb@linux.vnet.ibm.com>
Acked-by: Gavin Shan <shangw@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
PHB diagnostic buffer may be smaller than PAGE_SIZE, especially when
PAGE_SIZE > 4KB.
Signed-off-by: Brian W Hart <hartb@linux.vnet.ibm.com>
Acked-by: Gavin Shan <shangw@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
The powerpc 64-bit __copy_tofrom_user() function uses shifts to handle
unaligned invocations. However, these shifts were designed for
big-endian systems: On little-endian systems, they must shift in the
opposite direction.
This commit relies on the C preprocessor to insert the correct shifts
into the assembly code.
[ This is a rare but nasty LE issue. Most of the time we use the POWER7
optimised __copy_tofrom_user_power7 loop, but when it hits an exception
we fall back to the base __copy_tofrom_user loop. - Anton ]
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
The generic put_unaligned/get_unaligned macros were made endian-safe by
calling the appropriate endian dependent macros based on the endian type
of the powerpc processor.
Signed-off-by: Rajesh B Prathipati <rprathip@linux.vnet.ibm.com>
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
In EXCEPTION_PROLOG_COMMON() we check to see if the stack pointer (r1)
is valid when coming from the kernel. If it's not valid, we die but
with a nice oops message.
Currently we allocate a stack frame (subtract INT_FRAME_SIZE) before we
check to see if the stack pointer is negative. Unfortunately, this
won't detect a bad stack where r1 is less than INT_FRAME_SIZE.
This patch fixes the check to compare the modified r1 with
-INT_FRAME_SIZE. With this, bad kernel stack pointers (including NULL
pointers) are correctly detected again.
Kudos to Paulus for finding this.
Signed-off-by: Michael Neuling <mikey@neuling.org>
cc: stable@vger.kernel.org
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
At the moment the USB controller's pin muxing is not setup
correctly and causes a kernel panic upon system startup, so
disable the USB1 device tree node in the MPC5125 tower board
dts file.
The USB controller is connected to an USB3320 ULPI transceiver
and the device tree should receive an update to reflect correct
dependencies and required initialization data before the USB1
node can get re-enabled.
Signed-off-by: Matteo Facchinetti <matteo.facchinetti@sirius-es.it>
Signed-off-by: Anatolij Gustschin <agust@denx.de>
the 'soc' node in the MPC5125 "tower" board .dts has an '#interrupt-cells'
property although this node is not an interrupt controller
remove this erroneously placed property because starting with v3.13-rc1
lookup and resolution of 'interrupts' specs for peripherals gets misled
(tries to use the 'soc' as the interrupt parent which fails), emits
'no irq domain found' WARN() messages and breaks the boot process
[ best viewed with 'git diff -U5' to have DT node names in the context ]
Cc: Anatolij Gustschin <agust@denx.de>
Cc: linuxppc-dev@lists.ozlabs.org
Cc: devicetree@vger.kernel.org
Signed-off-by: Gerhard Sittig <gsi@denx.de>
Signed-off-by: Anatolij Gustschin <agust@denx.de>
Commit caaa4c804f ("KVM: PPC: Book3S HV: Fix physical address
calculations") unfortunately resulted in some low-order address bits
getting dropped in the case where the guest is creating a 4k HPTE
and the host page size is 64k. By getting the low-order bits from
hva rather than gpa we miss out on bits 12 - 15 in this case, since
hva is at page granularity. This puts the missing bits back in.
Reported-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Alexander Graf <agraf@suse.de>
We don't use PACATOC for PR. Avoid updating HOST_R2 with PR
KVM mode when both HV and PR are enabled in the kernel. Without this we
get the below crash
(qemu)
Unable to handle kernel paging request for data at address 0xffffffffffff8310
Faulting instruction address: 0xc00000000001d5a4
cpu 0x2: Vector: 300 (Data Access) at [c0000001dc53aef0]
pc: c00000000001d5a4: .vtime_delta.isra.1+0x34/0x1d0
lr: c00000000001d760: .vtime_account_system+0x20/0x60
sp: c0000001dc53b170
msr: 8000000000009032
dar: ffffffffffff8310
dsisr: 40000000
current = 0xc0000001d76c62d0
paca = 0xc00000000fef1100 softe: 0 irq_happened: 0x01
pid = 4472, comm = qemu-system-ppc
enter ? for help
[c0000001dc53b200] c00000000001d760 .vtime_account_system+0x20/0x60
[c0000001dc53b290] c00000000008d050 .kvmppc_handle_exit_pr+0x60/0xa50
[c0000001dc53b340] c00000000008f51c kvm_start_lightweight+0xb4/0xc4
[c0000001dc53b510] c00000000008cdf0 .kvmppc_vcpu_run_pr+0x150/0x2e0
[c0000001dc53b9e0] c00000000008341c .kvmppc_vcpu_run+0x2c/0x40
[c0000001dc53ba50] c000000000080af4 .kvm_arch_vcpu_ioctl_run+0x54/0x1b0
[c0000001dc53bae0] c00000000007b4c8 .kvm_vcpu_ioctl+0x478/0x730
[c0000001dc53bca0] c0000000002140cc .do_vfs_ioctl+0x4ac/0x770
[c0000001dc53bd80] c0000000002143e8 .SyS_ioctl+0x58/0xb0
[c0000001dc53be30] c000000000009e58 syscall_exit+0x0/0x98
Signed-off-by: Alexander Graf <agraf@suse.de>
We are passing pointers to the firmware for reads, we need to properly
convert the result as OPAL is always BE.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
opal_xscom_read uses a pointer to return the data so we need
to byteswap it on LE builds.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
A couple more device tree properties that need byte swapping.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
The MSI code is miscalculating quotas in little endian mode.
Add required byteswaps to fix this.
Before we claimed a quota of 65536, after the patch we
see the correct value of 256.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
We need to byteswap ibm,pcie-link-speed-stats.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
The NVRAM code has a number of endian issues. I noticed a very
confused error log count:
RTAS: 100663330 -------- RTAS event begin --------
100663330 == 0x06000022. 0x6 LE error logs and 0x22 BE error logs.
The pstore code has similar issues - if we write an oops in one
endian and attempt to read it in another we get junk.
Make both of these formats big endian, and byteswap as required.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
cpu_to_core_id() is missing a byteswap:
cat /sys/devices/system/cpu/cpu63/topology/core_id
201326592
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
During on LE boot we see:
Partition configured for 1073741824 cpus, operating system maximum is 2048.
Clearly missing a byteswap here.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
There is a bug in using ptrace to access FPRs via PTRACE_PEEKUSR /
PTRACE_POKEUSR. In effect, trying to access any of the FPRs always
really accesses FPR0, which does seriously break debugging :-)
The problem seems to have been introduced by commit 3ad26e5c44
(Merge branch 'for-kvm' into next).
[ It is indeed a merge conflict between Paul's FPU/VSX state rework
and my LE patches - Anton ]
Signed-off-by: Ulrich Weigand <Ulrich.Weigand@de.ibm.com>
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Commit ce11e48b7f ("KVM: PPC: E500: Add
userspace debug stub support") added "struct thread_struct" to the
stack of kvmppc_vcpu_run(). thread_struct is 1152 bytes on my build,
compared to 48 bytes for the recently-introduced "struct debug_reg".
Use the latter instead.
This fixes the following error:
cc1: warnings being treated as errors
arch/powerpc/kvm/booke.c: In function 'kvmppc_vcpu_run':
arch/powerpc/kvm/booke.c:760:1: error: the frame size of 1424 bytes is larger than 1024 bytes
make[2]: *** [arch/powerpc/kvm/booke.o] Error 1
make[1]: *** [arch/powerpc/kvm] Error 2
make[1]: *** Waiting for unfinished jobs....
Signed-off-by: Scott Wood <scottwood@freescale.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
The current logic sets the kdump base to min of 2G or ppc64_rma_size/2.
On PowerNV kernel the first memory block 'memory@0' can be very large,
equal to the DIMM size with ppc64_rma_size value capped to 1G. Hence on
PowerNV, kdump base is set to 512M resulting kdump to fail while allocating
paca array. This is because, paca need its memory from RMA region capped
at 256M (see allocate_pacas()).
This patch lowers the kdump base cap to 128M so that kdump kernel can
successfully get memory below 256M for paca allocation.
Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
I have recently found out that no iommu_groups could be found under
/sys/ on a P8. That prevents PCI passthrough from working.
During my investigation, I found out there seems to be a missing
iommu_register_group for PHB3. The following patch seems to fix the
problem. After applying it, I see iommu_groups under
/sys/kernel/iommu_groups/, and can also bind vfio-pci to an adapter,
which gives me a device at /dev/vfio/.
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
The bestcomm driver has been moved to drivers/dma, so to select
this driver by default additionally CONFIG_DMADEVICES has to be
enabled. Currently it is not enabled in the config despite existing
CONFIG_PPC_BESTCOMM=y in the config files. Fix it.
Signed-off-by: Anatolij Gustschin <agust@denx.de>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
At least some distros expect it these days; turn it on. Also, random
churn from doing a savedefconfig for the first time in a year or so.
Signed-off-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
In pte_alloc_one(), pgtable_page_ctor() is passed an address that has
not been converted by page_address() to the newly allocated PTE page.
When the PTE is freed, __pte_free_tlb() calls pgtable_page_dtor()
with an address to the PTE page that has been converted by page_address().
The mismatch in the PTE's page address causes pgtable_page_dtor() to access
invalid memory, so resources for that PTE (such as the page lock) is not
properly cleaned up.
On PPC32, only SMP kernels are affected.
On PPC64, only SMP kernels with 4K page size are affected.
This bug was introduced by commit d614bb0412
"powerpc: Move the pte free routines from common header".
On a preempt-rt kernel, a spinlock is dynamically allocated for each
PTE in pgtable_page_ctor(). When the PTE is freed, calling
pgtable_page_dtor() with a mismatched page address causes a memory leak,
as the pointer to the PTE's spinlock is bogus.
On mainline, there isn't any immediately obvious symptoms, but the
problem still exists here.
Fixes: d614bb0412 "powerpc: Move the pte free routes from common header"
Cc: Paul Mackerras <paulus@samba.org>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: linux-stable <stable@vger.kernel.org> # v3.10+
Signed-off-by: Hong H. Pham <hong.pham@windriver.com>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Allocate enough memory for the ocm_block structure, not just a pointer
to it.
Signed-off-by: Ilia Mirkin <imirkin@alum.mit.edu>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
A kernel configured with PPC_EARLY_DEBUG_BOOTX=y but PPC_PMAC=n and
PPC_MAPLE=n will fail to link:
btext.c:(.text+0x2d0fc): undefined reference to `.rmci_off'
btext.c:(.text+0x2d214): undefined reference to `.rmci_on'
Fix it by making the build of rmci_on/off() depend on
PPC_EARLY_DEBUG_BOOTX, which also enable the only code that uses them.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Now that the svcpu sync is interrupt aware we can enable interrupts
earlier in the exit code path again, moving 32bit and 64bit closer
together.
While at it, document the fact that we're always executing the exit
path with interrupts enabled so that the next person doesn't trap
over this.
Signed-off-by: Alexander Graf <agraf@suse.de>
As soon as we get back to our "highmem" handler in virtual address
space we may get preempted. Today the reason we can get preempted is
that we replay interrupts and all the lazy logic thinks we have
interrupts enabled.
However, it's not hard to make the code interruptible and that way
we can enable and handle interrupts even earlier.
This fixes random guest crashes that happened with CONFIG_PREEMPT=y
for me.
Signed-off-by: Alexander Graf <agraf@suse.de>
The kvmppc_copy_{to,from}_svcpu functions are publically visible,
so we should also export them in a header for others C files to
consume.
So far we didn't need this because we only called it from asm code.
The next patch will introduce a C caller.
Signed-off-by: Alexander Graf <agraf@suse.de>
We call a C helper to save all svcpu fields into our vcpu. The C
ABI states that r12 is considered volatile. However, we keep our
exit handler id in r12 currently.
So we need to save it away into a non-volatile register instead
that definitely does get preserved across the C call.
This bug usually didn't hit anyone yet since gcc is smart enough
to generate code that doesn't even need r12 which means it stayed
identical throughout the call by sheer luck. But we can't rely on
that.
Signed-off-by: Alexander Graf <agraf@suse.de>
for tmp_part->header.name:
it is "Terminating null required only for names < 12 chars".
so need to limit the %.12s for it in printk
additional info:
%12s limit the width, not for the original string output length
if name length is more than 12, it still can be fully displayed.
if name length is less than 12, the ' ' will be filled before name.
%.12s truly limit the original string output length (precision)
Signed-off-by: Chen Gang <gang.chen@asianux.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
In a recent patch:
commit c13f20ac48
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>
Cc: stable@vger.kernel.org
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
When CONFIG_SPARSEMEM_VMEMMAP option is used in kernel, makedumpfile fails
to filter vmcore dump as it fails to do vmemmap translations. So far
dump filtering on ppc64 never had to deal with vmemmap addresses seperately
as vmemmap regions where mapped in zone normal. But with the inclusion of
CONFIG_SPARSEMEM_VMEMMAP config option in kernel, this vmemmap address
translation support becomes necessary for dump filtering. For vmemmap adress
translation, few kernel symbols are needed by dump filtering tool. This patch
adds those symbols to vmcoreinfo, which a dump filtering tool can use for
filtering the kernel dump. Tested this changes successfully with makedumpfile
tool that supports vmemmap to physical address translation outside zone normal.
[ Removed unneeded #ifdef as suggested by Michael Ellerman --BenH ]
Signed-off-by: Hari Bathini <hbathini@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Stephen reported a failure in an allyesconfig build.
CONFIG_CPU_LITTLE_ENDIAN=y gets set but his toolchain is not
new enough to support little endian. We really want to
default to a big endian build; Ben suggested using a choice
which defaults to CPU_BIG_ENDIAN.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Currently if I cross build TAGS or cscope from x86 I get this:
% make ARCH=powerpc TAGS
gcc-4.8.real: error: unrecognized command line option ‘-mbig-endian’
GEN TAGS
%
I'm not setting CROSS_COMPILE= as logically I shouldn't need to and I
haven't needed to in the past when building TAGS or cscope. Also, the
above completess correct as the error is not fatal to the build.
This was caused by:
commit d72b080171
Author: Ian Munsie <imunsie@au1.ibm.com>
powerpc: Add ability to build little endian kernels
The below fixes this by testing for the -mbig-endian option before
adding it.
I've not done the same thing in the little endian case as if
-mlittle-endian doesn't exist, we probably want to fail quickly as you
probably have an old big endian compiler.
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
And in flush_hugetlb_page(), don't check whether vma is NULL after
we've already dereferenced it.
This was found by Dan using static analysis as described here:
https://lists.ozlabs.org/pipermail/linuxppc-dev/2013-November/113161.html
We currently get away with this because the callers that currently pass
NULL for vma seem to be 32-bit-only (e.g. highmem, and
CONFIG_DEBUG_PGALLOC in pgtable_32.c) Hugetlb is currently 64-bit only,
so we never saw a NULL vma here.
Signed-off-by: Scott Wood <scottwood@freescale.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
These lines were inoperative for four years, which puts some doubt into
their importance, and it's possible the fixed version will regress, but
at the very least they should be removed instead.
Signed-off-by: Adam Borowski <kilobyte@angband.pl>
Signed-off-by: Scott Wood <scottwood@freescale.com>
Commit beb2dc0a7a breaks the MPC8xx which
seems to not support using mfspr SPRN_TBRx instead of mftb/mftbu
despite what is written in the reference manual.
This patch reverts to the use of mftb/mftbu when CONFIG_8xx is
selected.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Scott Wood <scottwood@freescale.com>
If CONFIG_ALTIVEC is enabled for CoreNet64, and if we also
select CONFIG_E{5,6}500_CPU this may introduce -mcpu=e500mc64
into $CFLAGS. But Altivec option not allowed with e500mc64,
then some compiling errors occur like this:
CC arch/powerpc/lib/xor_vmx.o
arch/powerpc/lib/xor_vmx.c:1:0: error: AltiVec not supported in this target
make[1]: *** [arch/powerpc/lib/xor_vmx.o] Error 1
make: *** [arch/powerpc/lib] Error 2
So we should restrict e500mc64 in altivec scenario.
Signed-off-by: Tiejun Chen <tiejun.chen@windriver.com>
Signed-off-by: Scott Wood <scottwood@freescale.com>
Pull third set of powerpc updates from Benjamin Herrenschmidt:
"This is a small collection of random bug fixes and a few improvements
of Oops output which I deemed valuable enough to include as well.
The fixes are essentially recent build breakage and regressions, and a
couple of older bugs such as the DTL log duplication, the EEH issue
with PCI_COMMAND_MASTER and the problem with small contexts passed to
get/set_context with VSX enabled"
* 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc:
powerpc/signals: Mark VSX not saved with small contexts
powerpc/pseries: Fix SMP=n build of rng.c
powerpc: Make cpu_to_chip_id() available when SMP=n
powerpc/vio: Fix a dma_mask issue of vio
powerpc: booke: Fix build failures
powerpc: ppc64 address space capped at 32TB, mmap randomisation disabled
powerpc: Only print PACATMSCRATCH in oops when TM is active
powerpc/pseries: Duplicate dtl entries sometimes sent to userspace
powerpc: Remove a few lines of oops output
powerpc: Print DAR and DSISR on machine check oopses
powerpc: Fix __get_user_pages_fast() irq handling
powerpc/eeh: More accurate log
powerpc/eeh: Enable PCI_COMMAND_MASTER for PCI bridges
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>
Cc: stable@vger.kernel.org
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
In commit a489043 "Implement arch_get_random_long() based on H_RANDOM" I
broke the SMP=n build. We were getting plpar_wrappers.h via spinlock.h
which breaks when SMP=n.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
