In save_sprs() in process.c contains the following test:
if (cpu_has_feature(cpu_has_feature(CPU_FTR_ALTIVEC)))
t->vrsave = mfspr(SPRN_VRSAVE);
CPU feature with the mask 0x1 is CPU_FTR_COHERENT_ICACHE so the test
is equivilent to:
if (cpu_has_feature(CPU_FTR_ALTIVEC) &&
cpu_has_feature(CPU_FTR_COHERENT_ICACHE))
On CPUs without support for both (i.e G5) this results in vrsave not
being saved between context switches. The vector register save/restore
code doesn't use VRSAVE to determine which registers to save/restore,
but the value of VRSAVE is used to determine if altivec is being used
in several code paths.
Fixes: 152d523e63 ("powerpc: Create context switch helpers save_sprs() and restore_sprs()")
Cc: stable@vger.kernel.org
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Highlights:
- Restructure Linux PTE on Book3S/64 to Radix format from Paul Mackerras
- Book3s 64 MMU cleanup in preparation for Radix MMU from Aneesh Kumar K.V
- Add POWER9 cputable entry from Michael Neuling
- FPU/Altivec/VSX save/restore optimisations from Cyril Bur
- Add support for new ftrace ABI on ppc64le from Torsten Duwe
Various cleanups & minor fixes from:
- Adam Buchbinder, Andrew Donnellan, Balbir Singh, Christophe Leroy, Cyril
Bur, Luis Henriques, Madhavan Srinivasan, Pan Xinhui, Russell Currey,
Sukadev Bhattiprolu, Suraj Jitindar Singh.
General:
- atomics: Allow architectures to define their own __atomic_op_* helpers from
Boqun Feng
- Implement atomic{, 64}_*_return_* variants and acquire/release/relaxed
variants for (cmp)xchg from Boqun Feng
- Add powernv_defconfig from Jeremy Kerr
- Fix BUG_ON() reporting in real mode from Balbir Singh
- Add xmon command to dump OPAL msglog from Andrew Donnellan
- Add xmon command to dump process/task similar to ps(1) from Douglas Miller
- Clean up memory hotplug failure paths from David Gibson
pci/eeh:
- Redesign SR-IOV on PowerNV to give absolute isolation between VFs from Wei
Yang.
- EEH Support for SRIOV VFs from Wei Yang and Gavin Shan.
- PCI/IOV: Rename and export virtfn_{add, remove} from Wei Yang
- PCI: Add pcibios_bus_add_device() weak function from Wei Yang
- MAINTAINERS: Update EEH details and maintainership from Russell Currey
cxl:
- Support added to the CXL driver for running on both bare-metal and
hypervisor systems, from Christophe Lombard and Frederic Barrat.
- Ignore probes for virtual afu pci devices from Vaibhav Jain
perf:
- Export Power8 generic and cache events to sysfs from Sukadev Bhattiprolu
- hv-24x7: Fix usage with chip events, display change in counter values,
display domain indices in sysfs, eliminate domain suffix in event names,
from Sukadev Bhattiprolu
Freescale:
- Updates from Scott: "Highlights include 8xx optimizations, 32-bit checksum
optimizations, 86xx consolidation, e5500/e6500 cpu hotplug, more fman and
other dt bits, and minor fixes/cleanup."
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Merge tag 'powerpc-4.6-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux
Pull powerpc updates from Michael Ellerman:
"This was delayed a day or two by some build-breakage on old toolchains
which we've now fixed.
There's two PCI commits both acked by Bjorn.
There's one commit to mm/hugepage.c which is (co)authored by Kirill.
Highlights:
- Restructure Linux PTE on Book3S/64 to Radix format from Paul
Mackerras
- Book3s 64 MMU cleanup in preparation for Radix MMU from Aneesh
Kumar K.V
- Add POWER9 cputable entry from Michael Neuling
- FPU/Altivec/VSX save/restore optimisations from Cyril Bur
- Add support for new ftrace ABI on ppc64le from Torsten Duwe
Various cleanups & minor fixes from:
- Adam Buchbinder, Andrew Donnellan, Balbir Singh, Christophe Leroy,
Cyril Bur, Luis Henriques, Madhavan Srinivasan, Pan Xinhui, Russell
Currey, Sukadev Bhattiprolu, Suraj Jitindar Singh.
General:
- atomics: Allow architectures to define their own __atomic_op_*
helpers from Boqun Feng
- Implement atomic{, 64}_*_return_* variants and acquire/release/
relaxed variants for (cmp)xchg from Boqun Feng
- Add powernv_defconfig from Jeremy Kerr
- Fix BUG_ON() reporting in real mode from Balbir Singh
- Add xmon command to dump OPAL msglog from Andrew Donnellan
- Add xmon command to dump process/task similar to ps(1) from Douglas
Miller
- Clean up memory hotplug failure paths from David Gibson
pci/eeh:
- Redesign SR-IOV on PowerNV to give absolute isolation between VFs
from Wei Yang.
- EEH Support for SRIOV VFs from Wei Yang and Gavin Shan.
- PCI/IOV: Rename and export virtfn_{add, remove} from Wei Yang
- PCI: Add pcibios_bus_add_device() weak function from Wei Yang
- MAINTAINERS: Update EEH details and maintainership from Russell
Currey
cxl:
- Support added to the CXL driver for running on both bare-metal and
hypervisor systems, from Christophe Lombard and Frederic Barrat.
- Ignore probes for virtual afu pci devices from Vaibhav Jain
perf:
- Export Power8 generic and cache events to sysfs from Sukadev
Bhattiprolu
- hv-24x7: Fix usage with chip events, display change in counter
values, display domain indices in sysfs, eliminate domain suffix in
event names, from Sukadev Bhattiprolu
Freescale:
- Updates from Scott: "Highlights include 8xx optimizations, 32-bit
checksum optimizations, 86xx consolidation, e5500/e6500 cpu
hotplug, more fman and other dt bits, and minor fixes/cleanup"
* tag 'powerpc-4.6-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (179 commits)
powerpc: Fix unrecoverable SLB miss during restore_math()
powerpc/8xx: Fix do_mtspr_cpu6() build on older compilers
powerpc/rcpm: Fix build break when SMP=n
powerpc/book3e-64: Use hardcoded mttmr opcode
powerpc/fsl/dts: Add "jedec,spi-nor" flash compatible
powerpc/T104xRDB: add tdm riser card node to device tree
powerpc32: PAGE_EXEC required for inittext
powerpc/mpc85xx: Add pcsphy nodes to FManV3 device tree
powerpc/mpc85xx: Add MDIO bus muxing support to the board device tree(s)
powerpc/86xx: Introduce and use common dtsi
powerpc/86xx: Update device tree
powerpc/86xx: Move dts files to fsl directory
powerpc/86xx: Switch to kconfig fragments approach
powerpc/86xx: Update defconfigs
powerpc/86xx: Consolidate common platform code
powerpc32: Remove one insn in mulhdu
powerpc32: small optimisation in flush_icache_range()
powerpc: Simplify test in __dma_sync()
powerpc32: move xxxxx_dcache_range() functions inline
powerpc32: Remove clear_pages() and define clear_page() inline
...
This patch adds the ability to be able to save the VSX registers to the
thread struct without giving up (disabling the facility) next time the
process returns to userspace.
This patch builds on a previous optimisation for the FPU and VEC registers
in the thread copy path to avoid a possibly pointless reload of VSX state.
Signed-off-by: Cyril Bur <cyrilbur@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This patch adds the ability to be able to save the VEC registers to the
thread struct without giving up (disabling the facility) next time the
process returns to userspace.
This patch builds on a previous optimisation for the FPU registers in the
thread copy path to avoid a possibly pointless reload of VEC state.
Signed-off-by: Cyril Bur <cyrilbur@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This patch adds the ability to be able to save the FPU registers to the
thread struct without giving up (disabling the facility) next time the
process returns to userspace.
This patch optimises the thread copy path (as a result of a fork() or
clone()) so that the parent thread can return to userspace with hot
registers avoiding a possibly pointless reload of FPU register state.
Signed-off-by: Cyril Bur <cyrilbur@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This prepares for the decoupling of saving {fpu,altivec,vsx} registers and
marking {fpu,altivec,vsx} as being unused by a thread.
Currently giveup_{fpu,altivec,vsx}() does both however optimisations to
task switching can be made if these two operations are decoupled.
save_all() will permit the saving of registers to thread structs and leave
threads MSR with bits enabled.
This patch introduces no functional change.
Signed-off-by: Cyril Bur <cyrilbur@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Currently the FPU, VEC and VSX facilities are lazily loaded. This is not
a problem unless a process is using these facilities.
Modern versions of GCC are very good at automatically vectorising code,
new and modernised workloads make use of floating point and vector
facilities, even the kernel makes use of vectorised memcpy.
All this combined greatly increases the cost of a syscall since the
kernel uses the facilities sometimes even in syscall fast-path making it
increasingly common for a thread to take an *_unavailable exception soon
after a syscall, not to mention potentially taking all three.
The obvious overcompensation to this problem is to simply always load
all the facilities on every exit to userspace. Loading up all FPU, VEC
and VSX registers every time can be expensive and if a workload does
avoid using them, it should not be forced to incur this penalty.
An 8bit counter is used to detect if the registers have been used in the
past and the registers are always loaded until the value wraps to back
to zero.
Several versions of the assembly in entry_64.S were tested:
1. Always calling C.
2. Performing a common case check and then calling C.
3. A complex check in asm.
After some benchmarking it was determined that avoiding C in the common
case is a performance benefit (option 2). The full check in asm (option
3) greatly complicated that codepath for a negligible performance gain
and the trade-off was deemed not worth it.
Signed-off-by: Cyril Bur <cyrilbur@gmail.com>
[mpe: Move load_vec in the struct to fill an existing hole, reword change log]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
fixup
Currently when threads get scheduled off they always giveup the FPU,
Altivec (VMX) and Vector (VSX) units if they were using them. When they are
scheduled back on a fault is then taken to enable each facility and load
registers. As a result explicitly disabling FPU/VMX/VSX has not been
necessary.
Future changes and optimisations remove this mandatory giveup and fault
which could cause calls such as clone() and fork() to copy threads and run
them later with FPU/VMX/VSX enabled but no registers loaded.
This patch starts the process of having MSR_{FP,VEC,VSX} mean that a
threads registers are hot while not having MSR_{FP,VEC,VSX} means that the
registers must be loaded. This allows for a smarter return to userspace.
Signed-off-by: Cyril Bur <cyrilbur@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Replace calls to get_random_int() followed by a cast to (unsigned long)
with calls to get_random_long(). Also address shifting bug which, in
case of x86 removed entropy mask for mmap_rnd_bits values > 31 bits.
Signed-off-by: Daniel Cashman <dcashman@android.com>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: David S. Miller <davem@davemloft.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Nick Kralevich <nnk@google.com>
Cc: Jeff Vander Stoep <jeffv@google.com>
Cc: Mark Salyzyn <salyzyn@android.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
- tm: Block signal return from setting invalid MSR state from Michael Neuling
- tm: Check for already reclaimed tasks from Michael Neuling
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Merge tag 'powerpc-4.4-3' into next
Merge the two TM fixes we merged in 4.4. We are about to merge selftests
for these, and without the fixes the selftests will oops.
powerpc fixes for 4.4 #2
- tm: Block signal return from setting invalid MSR state from Michael Neuling
- tm: Check for already reclaimed tasks from Michael Neuling
Print MSR TM bits in oops messages. This appends them to the end
like this:
MSR: 8000000502823031 <SF,VEC,VSX,FP,ME,IR,DR,LE,TM[TE]>
You get the TM[] only if at least one TM MSR bit is set. Inside the
TM[], E means Enabled (bit 32), S means Suspended (bit 33), and T
means Transactional (bit 34)
If no bits are set, you get no TM[] output.
Include rework of printbits() to handle this case.
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Two DSCR tests have a hack in them:
/*
* XXX: Force a context switch out so that DSCR
* current value is copied into the thread struct
* which is required for the child to inherit the
* changed value.
*/
sleep(1);
We should not be working around this in the testcase, it is a kernel bug.
Fix it by copying the current DSCR to the child, instead of what we
had in the thread struct at last context switch.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
commit 152d523e63 ("powerpc: Create context switch helpers save_sprs()
and restore_sprs()") moved the restore of SPRs after the call to _switch().
There is an issue with this approach - new tasks do not return through
_switch(), they are set up by copy_thread() to directly return through
ret_from_fork() or ret_from_kernel_thread(). This means restore_sprs() is
not getting called for new tasks.
Fix this by moving restore_sprs() before _switch().
Fixes: 152d523e63 ("powerpc: Create context switch helpers save_sprs() and restore_sprs()")
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Commit a0e72cf12b ("powerpc: Create msr_check_and_{set,clear}()")
removed a call to check_if_tm_restore_required() in the
enable_kernel_*() functions. Add them back in.
Fixes: a0e72cf12b ("powerpc: Create msr_check_and_{set,clear}()")
Reported-by: Rashmica Gupta <rashmicy@gmail.com>
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Remove a bunch of unnecessary fallback functions and group
things in a more logical way.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Most of __switch_to() is housekeeping, TLB batching, timekeeping etc.
Move these away from the more complex and critical context switching
code.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Create a single function that flushes everything (FP, VMX, VSX, SPE).
Doing this all at once means we only do one MSR write.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Create a single function that gives everything up (FP, VMX, VSX, SPE).
Doing this all at once means we only do one MSR write.
A context switch microbenchmark using yield():
http://ozlabs.org/~anton/junkcode/context_switch2.c
./context_switch2 --test=yield --fp --altivec --vector 0 0
shows an improvement of 3% on POWER8.
Signed-off-by: Anton Blanchard <anton@samba.org>
[mpe: giveup_all() needs to be EXPORT_SYMBOL'ed]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
More consolidation of our MSR available bit handling.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Add a boot option that strictly manages the MSR unavailable bits.
This catches kernel uses of FP/Altivec/SPE that would otherwise
corrupt user state.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Create helper functions to set and clear MSR bits after first
checking if they are already set. Grouping them will make it
easy to avoid the MSR writes in a subsequent optimisation.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Move the MSR modification into c. Removing it from the assembly
function will allow us to avoid costly MSR writes by batching them
up.
Check the FP and VMX bits before calling the relevant giveup_*()
function. This makes giveup_vsx() and flush_vsx_to_thread() perform
more like their sister functions, and allows us to use
flush_vsx_to_thread() in the signal code.
Move the check_if_tm_restore_required() check in.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Move the MSR modification into new c functions. Removing it from
the low level functions will allow us to avoid costly MSR writes
by batching them up.
Move the check_if_tm_restore_required() check into these new functions.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
mtmsrd_isync() will do an mtmsrd followed by an isync on older
processors. On newer processors we avoid the isync via a feature fixup.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Instead of having multiple giveup_*_maybe_transactional() functions,
separate out the TM check into a new function called
check_if_tm_restore_required().
This will make it easier to optimise the giveup_*() functions in a
subsequent patch.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The UP only lazy floating point and vector optimisations were written
back when SMP was not common, and neither glibc nor gcc used vector
instructions. Now SMP is very common, glibc aggressively uses vector
instructions and gcc autovectorises.
We want to add new optimisations that apply to both UP and SMP, but
in preparation for that remove these UP only optimisations.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Move all our context switch SPR save and restore code into two
helpers. We do a few optimisations:
- Group all mfsprs and all mtsprs. In many cases an mtspr sets a
scoreboarding bit that an mfspr waits on, so the current practise of
mfspr A; mtspr A; mfpsr B; mtspr B is the worst scheduling we can
do.
- SPR writes are slow, so check that the value is changing before
writing it.
A context switch microbenchmark using yield():
http://ozlabs.org/~anton/junkcode/context_switch2.c
./context_switch2 --test=yield 0 0
shows an improvement of almost 10% on POWER8.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Currently we can hit a scenario where we'll tm_reclaim() twice. This
results in a TM bad thing exception because the second reclaim occurs
when not in suspend mode.
The scenario in which this can happen is the following. We attempt to
deliver a signal to userspace. To do this we need obtain the stack
pointer to write the signal context. To get this stack pointer we
must tm_reclaim() in case we need to use the checkpointed stack
pointer (see get_tm_stackpointer()). Normally we'd then return
directly to userspace to deliver the signal without going through
__switch_to().
Unfortunatley, if at this point we get an error (such as a bad
userspace stack pointer), we need to exit the process. The exit will
result in a __switch_to(). __switch_to() will attempt to save the
process state which results in another tm_reclaim(). This
tm_reclaim() now causes a TM Bad Thing exception as this state has
already been saved and the processor is no longer in TM suspend mode.
Whee!
This patch checks the state of the MSR to ensure we are TM suspended
before we attempt the tm_reclaim(). If we've already saved the state
away, we should no longer be in TM suspend mode. This has the
additional advantage of checking for a potential TM Bad Thing
exception.
Found using syscall fuzzer.
Fixes: fb09692e71 ("powerpc: Add reclaim and recheckpoint functions for context switching transactional memory processes")
Cc: stable@vger.kernel.org # v3.9+
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
- Support "hybrid" iommu/direct DMA ops for coherent_mask < dma_mask from Benjamin Herrenschmidt
- EEH fixes for SRIOV from Gavin
- Introduce rtas_get_sensor_fast() for IRQ handlers from Thomas Huth
- Use hardware RNG for arch_get_random_seed_* not arch_get_random_* from Paul Mackerras
- Seccomp filter support from Michael Ellerman
- opal_cec_reboot2() handling for HMIs & machine checks from Mahesh Salgaonkar
- Add powerpc timebase as a trace clock source from Naveen N. Rao
- Misc cleanups in the xmon, signal & SLB code from Anshuman Khandual
- Add an inline function to update POWER8 HID0 from Gautham R. Shenoy
- Fix pte_pagesize_index() crash on 4K w/64K hash from Michael Ellerman
- Drop support for 64K local store on 4K kernels from Michael Ellerman
- move dma_get_required_mask() from pnv_phb to pci_controller_ops from Andrew Donnellan
- Initialize distance lookup table from drconf path from Nikunj A Dadhania
- Enable RTC class support from Vaibhav Jain
- Disable automatically blocked PCI config from Gavin Shan
- Add LEDs driver for PowerNV platform from Vasant Hegde
- Fix endianness issues in the HVSI driver from Laurent Dufour
- Kexec endian fixes from Samuel Mendoza-Jonas
- Fix corrupted pdn list from Gavin Shan
- Fix fenced PHB caused by eeh_slot_error_detail() from Gavin Shan
- Freescale updates from Scott: Highlights include 32-bit memcpy/memset
optimizations, checksum optimizations, 85xx config fragments and updates,
device tree updates, e6500 fixes for non-SMP, and misc cleanup and minor
fixes.
- A ton of cxl updates & fixes:
- Add explicit precision specifiers from Rasmus Villemoes
- use more common format specifier from Rasmus Villemoes
- Destroy cxl_adapter_idr on module_exit from Johannes Thumshirn
- Destroy afu->contexts_idr on release of an afu from Johannes Thumshirn
- Compile with -Werror from Daniel Axtens
- EEH support from Daniel Axtens
- Plug irq_bitmap getting leaked in cxl_context from Vaibhav Jain
- Add alternate MMIO error handling from Ian Munsie
- Allow release of contexts which have been OPENED but not STARTED from Andrew Donnellan
- Remove use of macro DEFINE_PCI_DEVICE_TABLE from Vaishali Thakkar
- Release irqs if memory allocation fails from Vaibhav Jain
- Remove racy attempt to force EEH invocation in reset from Daniel Axtens
- Fix + cleanup error paths in cxl_dev_context_init from Ian Munsie
- Fix force unmapping mmaps of contexts allocated through the kernel api from Ian Munsie
- Set up and enable PSL Timebase from Philippe Bergheaud
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Merge tag 'powerpc-4.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux
Pull powerpc updates from Michael Ellerman:
- support "hybrid" iommu/direct DMA ops for coherent_mask < dma_mask
from Benjamin Herrenschmidt
- EEH fixes for SRIOV from Gavin
- introduce rtas_get_sensor_fast() for IRQ handlers from Thomas Huth
- use hardware RNG for arch_get_random_seed_* not arch_get_random_*
from Paul Mackerras
- seccomp filter support from Michael Ellerman
- opal_cec_reboot2() handling for HMIs & machine checks from Mahesh
Salgaonkar
- add powerpc timebase as a trace clock source from Naveen N. Rao
- misc cleanups in the xmon, signal & SLB code from Anshuman Khandual
- add an inline function to update POWER8 HID0 from Gautham R. Shenoy
- fix pte_pagesize_index() crash on 4K w/64K hash from Michael Ellerman
- drop support for 64K local store on 4K kernels from Michael Ellerman
- move dma_get_required_mask() from pnv_phb to pci_controller_ops from
Andrew Donnellan
- initialize distance lookup table from drconf path from Nikunj A
Dadhania
- enable RTC class support from Vaibhav Jain
- disable automatically blocked PCI config from Gavin Shan
- add LEDs driver for PowerNV platform from Vasant Hegde
- fix endianness issues in the HVSI driver from Laurent Dufour
- kexec endian fixes from Samuel Mendoza-Jonas
- fix corrupted pdn list from Gavin Shan
- fix fenced PHB caused by eeh_slot_error_detail() from Gavin Shan
- Freescale updates from Scott: Highlights include 32-bit memcpy/memset
optimizations, checksum optimizations, 85xx config fragments and
updates, device tree updates, e6500 fixes for non-SMP, and misc
cleanup and minor fixes.
- a ton of cxl updates & fixes:
- add explicit precision specifiers from Rasmus Villemoes
- use more common format specifier from Rasmus Villemoes
- destroy cxl_adapter_idr on module_exit from Johannes Thumshirn
- destroy afu->contexts_idr on release of an afu from Johannes
Thumshirn
- compile with -Werror from Daniel Axtens
- EEH support from Daniel Axtens
- plug irq_bitmap getting leaked in cxl_context from Vaibhav Jain
- add alternate MMIO error handling from Ian Munsie
- allow release of contexts which have been OPENED but not STARTED
from Andrew Donnellan
- remove use of macro DEFINE_PCI_DEVICE_TABLE from Vaishali Thakkar
- release irqs if memory allocation fails from Vaibhav Jain
- remove racy attempt to force EEH invocation in reset from Daniel
Axtens
- fix + cleanup error paths in cxl_dev_context_init from Ian Munsie
- fix force unmapping mmaps of contexts allocated through the kernel
api from Ian Munsie
- set up and enable PSL Timebase from Philippe Bergheaud
* tag 'powerpc-4.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (140 commits)
cxl: Set up and enable PSL Timebase
cxl: Fix force unmapping mmaps of contexts allocated through the kernel api
cxl: Fix + cleanup error paths in cxl_dev_context_init
powerpc/eeh: Fix fenced PHB caused by eeh_slot_error_detail()
powerpc/pseries: Cleanup on pci_dn_reconfig_notifier()
powerpc/pseries: Fix corrupted pdn list
powerpc/powernv: Enable LEDS support
powerpc/iommu: Set default DMA offset in dma_dev_setup
cxl: Remove racy attempt to force EEH invocation in reset
cxl: Release irqs if memory allocation fails
cxl: Remove use of macro DEFINE_PCI_DEVICE_TABLE
powerpc/powernv: Fix mis-merge of OPAL support for LEDS driver
powerpc/powernv: Reset HILE before kexec_sequence()
powerpc/kexec: Reset secondary cpu endianness before kexec
powerpc/hvsi: Fix endianness issues in the HVSI driver
leds/powernv: Add driver for PowerNV platform
powerpc/powernv: Create LED platform device
powerpc/powernv: Add OPAL interfaces for accessing and modifying system LED states
powerpc/powernv: Fix the log message when disabling VF
cxl: Allow release of contexts which have been OPENED but not STARTED
...
Currently tm_orig_msr is getting used during process context switch only.
Then there is ckpt_regs which saves the checkpointed userspace context
The MSR slot contained in ckpt_regs structure can be used during process
context switch instead of tm_orig_msr, thus allowing us to drop it from
thread_struct structure. This patch does that change.
Acked-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Anshuman Khandual <khandual@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
enable_kernel_vsx() function was commented since anything was using
it. However, vmx-crypto driver uses VSX instructions which are
only available if VSX is enable. Otherwise it rises an exception oops.
This patch uncomment enable_kernel_vsx() routine and makes it available.
Signed-off-by: Leonidas S. Barbosa <leosilva@linux.vnet.ibm.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
The process context switch code no longer uses dscr_default variable
from the sysfs.c file. The variable became unused when we started
storing the CPU specific DSCR value in the PACA structure instead.
This patch just removes this extern declaration. It was originally
added by the following commit.
Signed-off-by: Anshuman Khandual <khandual@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The 'arg' argument to copy_thread() is only ever used when forking a new
kernel thread. Hence, rename it to 'kthread_arg' for clarity.
Signed-off-by: Alex Dowad <alexinbeijing@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Back in 2009 we merged 501cb16d3c "Randomise PIEs", which added support for
randomizing PIE (Position Independent Executable) binaries.
That commit added randomize_et_dyn(), which correctly randomized the addresses,
but failed to honor PF_RANDOMIZE. That means it was not possible to disable PIE
randomization via the personality flag, or /proc/sys/kernel/randomize_va_space.
Since then there has been generic support for PIE randomization added to
binfmt_elf.c, selectable via ARCH_BINFMT_ELF_RANDOMIZE_PIE.
Enabling that allows us to drop randomize_et_dyn(), which means we start
honoring PF_RANDOMIZE correctly.
It also causes a fairly major change to how we layout PIE binaries.
Currently we will place the binary at 512MB-520MB for 32 bit binaries, or
512MB-1.5GB for 64 bit binaries, eg:
$ cat /proc/$$/maps
4e550000-4e580000 r-xp 00000000 08:02 129813 /bin/dash
4e580000-4e590000 rw-p 00020000 08:02 129813 /bin/dash
10014110000-10014140000 rw-p 00000000 00:00 0 [heap]
3fffaa3f0000-3fffaa5a0000 r-xp 00000000 08:02 921 /lib/powerpc64le-linux-gnu/libc-2.19.so
3fffaa5a0000-3fffaa5b0000 rw-p 001a0000 08:02 921 /lib/powerpc64le-linux-gnu/libc-2.19.so
3fffaa5c0000-3fffaa5d0000 rw-p 00000000 00:00 0
3fffaa5d0000-3fffaa5f0000 r-xp 00000000 00:00 0 [vdso]
3fffaa5f0000-3fffaa620000 r-xp 00000000 08:02 1246 /lib/powerpc64le-linux-gnu/ld-2.19.so
3fffaa620000-3fffaa630000 rw-p 00020000 08:02 1246 /lib/powerpc64le-linux-gnu/ld-2.19.so
3ffffc340000-3ffffc370000 rw-p 00000000 00:00 0 [stack]
With this commit applied we don't do any special randomisation for the binary,
and instead rely on mmap randomisation. This means the binary ends up at high
addresses, eg:
$ cat /proc/$$/maps
3fff99820000-3fff999d0000 r-xp 00000000 08:02 921 /lib/powerpc64le-linux-gnu/libc-2.19.so
3fff999d0000-3fff999e0000 rw-p 001a0000 08:02 921 /lib/powerpc64le-linux-gnu/libc-2.19.so
3fff999f0000-3fff99a00000 rw-p 00000000 00:00 0
3fff99a00000-3fff99a20000 r-xp 00000000 00:00 0 [vdso]
3fff99a20000-3fff99a50000 r-xp 00000000 08:02 1246 /lib/powerpc64le-linux-gnu/ld-2.19.so
3fff99a50000-3fff99a60000 rw-p 00020000 08:02 1246 /lib/powerpc64le-linux-gnu/ld-2.19.so
3fff99a60000-3fff99a90000 r-xp 00000000 08:02 129813 /bin/dash
3fff99a90000-3fff99aa0000 rw-p 00020000 08:02 129813 /bin/dash
3fffc3de0000-3fffc3e10000 rw-p 00000000 00:00 0 [stack]
3fffc55e0000-3fffc5610000 rw-p 00000000 00:00 0 [heap]
Although this should be OK, it's possible it might break badly written
binaries that make assumptions about the address space layout.
Signed-off-by: Vineeth Vijayan <vvijayan@mvista.com>
[mpe: Rewrite changelog]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
mod_return_to_handler is the same as return_to_handler, except
it handles the change of the TOC (r2). Add this into
return_to_handler and remove mod_return_to_handler.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
We really don't want to take a pagefault in show_instructions,
so use probe_kernel_address instead of __get_user.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This still has not been merged and now powerpc is the only arch that does
not have this change. Sorry about missing linuxppc-dev before.
V2->V2
- Fix up to work against 3.18-rc1
__get_cpu_var() is used for multiple purposes in the kernel source. One of
them is address calculation via the form &__get_cpu_var(x). This calculates
the address for the instance of the percpu variable of the current processor
based on an offset.
Other use cases are for storing and retrieving data from the current
processors percpu area. __get_cpu_var() can be used as an lvalue when
writing data or on the right side of an assignment.
__get_cpu_var() is defined as :
__get_cpu_var() always only does an address determination. However, store
and retrieve operations could use a segment prefix (or global register on
other platforms) to avoid the address calculation.
this_cpu_write() and this_cpu_read() can directly take an offset into a
percpu area and use optimized assembly code to read and write per cpu
variables.
This patch converts __get_cpu_var into either an explicit address
calculation using this_cpu_ptr() or into a use of this_cpu operations that
use the offset. Thereby address calculations are avoided and less registers
are used when code is generated.
At the end of the patch set all uses of __get_cpu_var have been removed so
the macro is removed too.
The patch set includes passes over all arches as well. Once these operations
are used throughout then specialized macros can be defined in non -x86
arches as well in order to optimize per cpu access by f.e. using a global
register that may be set to the per cpu base.
Transformations done to __get_cpu_var()
1. Determine the address of the percpu instance of the current processor.
DEFINE_PER_CPU(int, y);
int *x = &__get_cpu_var(y);
Converts to
int *x = this_cpu_ptr(&y);
2. Same as #1 but this time an array structure is involved.
DEFINE_PER_CPU(int, y[20]);
int *x = __get_cpu_var(y);
Converts to
int *x = this_cpu_ptr(y);
3. Retrieve the content of the current processors instance of a per cpu
variable.
DEFINE_PER_CPU(int, y);
int x = __get_cpu_var(y)
Converts to
int x = __this_cpu_read(y);
4. Retrieve the content of a percpu struct
DEFINE_PER_CPU(struct mystruct, y);
struct mystruct x = __get_cpu_var(y);
Converts to
memcpy(&x, this_cpu_ptr(&y), sizeof(x));
5. Assignment to a per cpu variable
DEFINE_PER_CPU(int, y)
__get_cpu_var(y) = x;
Converts to
__this_cpu_write(y, x);
6. Increment/Decrement etc of a per cpu variable
DEFINE_PER_CPU(int, y);
__get_cpu_var(y)++
Converts to
__this_cpu_inc(y)
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
CC: Paul Mackerras <paulus@samba.org>
Signed-off-by: Christoph Lameter <cl@linux.com>
[mpe: Fix build errors caused by set/or_softirq_pending(), and rework
assignment in __set_breakpoint() to use memcpy().]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Michael points out that __get_SP() is a pretty horrible
function name. Let's give it a better name.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Li Zhong points out an issue with our current __get_SP()
implementation. If ftrace function tracing is enabled (ie -pg
profiling using _mcount) we spill a stack frame on 64bit all the
time.
If a function calls __get_SP() and later calls a function that is
tail call optimised, we will pop the stack frame and the value
returned by __get_SP() is no longer valid. An example from Li can
be found in save_stack_trace -> save_context_stack:
c0000000000432c0 <.save_stack_trace>:
c0000000000432c0: mflr r0
c0000000000432c4: std r0,16(r1)
c0000000000432c8: stdu r1,-128(r1) <-- stack frame for _mcount
c0000000000432cc: std r3,112(r1)
c0000000000432d0: bl <._mcount>
c0000000000432d4: nop
c0000000000432d8: mr r4,r1 <-- __get_SP()
c0000000000432dc: ld r5,632(r13)
c0000000000432e0: ld r3,112(r1)
c0000000000432e4: li r6,1
c0000000000432e8: addi r1,r1,128 <-- pop stack frame
c0000000000432ec: ld r0,16(r1)
c0000000000432f0: mtlr r0
c0000000000432f4: b <.save_context_stack> <-- tail call optimized
save_context_stack ends up with a stack pointer below the current
one, and it is likely to be scribbled over.
Fix this by making __get_SP() a function which returns the
callers stack frame. Also replace inline assembly which grabs
the stack pointer in save_stack_trace and show_stack with
__get_SP().
This also fixes an issue with perf_arch_fetch_caller_regs().
It currently unwinds the stack once, which will skip a
valid stack frame on a leaf function. With the __get_SP() fixes
in this patch, we never need to unwind the stack frame to get
to the first interesting frame.
We have to export __get_SP() because perf_arch_fetch_caller_regs()
(which is used in modules) calls it from a header file.
Reported-by: Li Zhong <zhong@linux.vnet.ibm.com>
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Some people see things like "Exception: 501" in stack traces in dmesg
and assume that means that something has gone badly wrong, when in
fact "Exception: 501" just means a device interrupt was taken.
This changes "Exception" to "interrupt" to make it clearer that we
are just recording the fact of a change in control flow rather than
some error condition.
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
The previous patch left a bit of a wart in copy_process(). Clean it up a
bit by moving the logic out into a helper.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
We now only support cpus that use an SLB, so we don't need an MMU
feature to indicate that.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Correct the DSCR SPR becoming temporarily corrupted if a task is
context switched during a transaction.
The problem occurs while suspending the task and is caused by saving
the DSCR to thread.dscr after it has already been set to the CPU's
default value:
__switch_to() calls __switch_to_tm()
which calls tm_reclaim_task()
which calls tm_reclaim_thread()
which calls tm_reclaim()
where the DSCR is set to the CPU's default
__switch_to() calls _switch()
where thread.dscr is set to the DSCR
When the task is resumed, it's transaction will be doomed (as usual)
and the DSCR SPR will be corrupted, although the checkpointed value
will be correct. Therefore the DSCR will be immediately corrected by
the transaction aborting, unless it has been suspended. In that case
the incorrect value can be seen by the task until it resumes the
transaction.
The fix is to treat the DSCR similarly to the TAR and save it early
in __switch_to().
A program exposing the problem is added to the kernel self tests as:
tools/testing/selftests/powerpc/tm/tm-resched-dscr.
Signed-off-by: Sam Bobroff <sam.bobroff@au1.ibm.com>
CC: <stable@vger.kernel.org> [v3.10+]
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Currently, on 8641D, which doesn't set CONFIG_HAVE_HW_BREAKPOINT
we get the following splat:
BUG: using smp_processor_id() in preemptible [00000000] code: login/1382
caller is set_breakpoint+0x1c/0xa0
CPU: 0 PID: 1382 Comm: login Not tainted 3.15.0-rc3-00041-g2aafe1a4d451 #1
Call Trace:
[decd5d80] [c0008dc4] show_stack+0x50/0x158 (unreliable)
[decd5dc0] [c03c6fa0] dump_stack+0x7c/0xdc
[decd5de0] [c01f8818] check_preemption_disabled+0xf4/0x104
[decd5e00] [c00086b8] set_breakpoint+0x1c/0xa0
[decd5e10] [c00d4530] flush_old_exec+0x2bc/0x588
[decd5e40] [c011c468] load_elf_binary+0x2ac/0x1164
[decd5ec0] [c00d35f8] search_binary_handler+0xc4/0x1f8
[decd5ef0] [c00d4ee8] do_execve+0x3d8/0x4b8
[decd5f40] [c001185c] ret_from_syscall+0x0/0x38
--- Exception: c01 at 0xfeee554
LR = 0xfeee7d4
The call path in this case is:
flush_thread
--> set_debug_reg_defaults
--> set_breakpoint
--> __get_cpu_var
Since preemption is enabled in the cleanup of flush thread, and
there is no need to disable it, introduce the distinction between
set_breakpoint and __set_breakpoint, leaving only the flush_thread
instance as the current user of set_breakpoint.
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
None of the callers check the return value, so it might as
well not have one at all.
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Change how we setup registers for ret_from_kernel_thread. In
ABIv1, instead of passing a function descriptor in, dereference
it and pass the target in directly.
Use ppc_global_function_entry to get it right on both ABIv1 and ABIv2.
Signed-off-by: Anton Blanchard <anton@samba.org>
We can't take an IRQ when we're about to do a trechkpt as our GPR state is set
to user GPR values.
We've hit this when running some IBM Java stress tests in the lab resulting in
the following dump:
cpu 0x3f: Vector: 700 (Program Check) at [c000000007eb3d40]
pc: c000000000050074: restore_gprs+0xc0/0x148
lr: 00000000b52a8184
sp: ac57d360
msr: 8000000100201030
current = 0xc00000002c500000
paca = 0xc000000007dbfc00 softe: 0 irq_happened: 0x00
pid = 34535, comm = Pooled Thread #
R00 = 00000000b52a8184 R16 = 00000000b3e48fda
R01 = 00000000ac57d360 R17 = 00000000ade79bd8
R02 = 00000000ac586930 R18 = 000000000fac9bcc
R03 = 00000000ade60000 R19 = 00000000ac57f930
R04 = 00000000f6624918 R20 = 00000000ade79be8
R05 = 00000000f663f238 R21 = 00000000ac218a54
R06 = 0000000000000002 R22 = 000000000f956280
R07 = 0000000000000008 R23 = 000000000000007e
R08 = 000000000000000a R24 = 000000000000000c
R09 = 00000000b6e69160 R25 = 00000000b424cf00
R10 = 0000000000000181 R26 = 00000000f66256d4
R11 = 000000000f365ec0 R27 = 00000000b6fdcdd0
R12 = 00000000f66400f0 R28 = 0000000000000001
R13 = 00000000ada71900 R29 = 00000000ade5a300
R14 = 00000000ac2185a8 R30 = 00000000f663f238
R15 = 0000000000000004 R31 = 00000000f6624918
pc = c000000000050074 restore_gprs+0xc0/0x148
cfar= c00000000004fe28 dont_restore_vec+0x1c/0x1a4
lr = 00000000b52a8184
msr = 8000000100201030 cr = 24804888
ctr = 0000000000000000 xer = 0000000000000000 trap = 700
This moves tm_recheckpoint to a C function and moves the tm_restore_sprs into
that function. It then adds IRQ disabling over the trechkpt critical section.
It also sets the TEXASR FS in the signals code to ensure this is never set now
that we explictly write the TM sprs in tm_recheckpoint.
Signed-off-by: Michael Neuling <mikey@neuling.org>
cc: stable@vger.kernel.org
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
When we fork/clone we currently don't copy any of the TM state to the new
thread. This results in a TM bad thing (program check) when the new process is
switched in as the kernel does a tmrechkpt with TEXASR FS not set. Also, since
R1 is from userspace, we trigger the bad kernel stack pointer detection. So we
end up with something like this:
Bad kernel stack pointer 0 at c0000000000404fc
cpu 0x2: Vector: 700 (Program Check) at [c00000003ffefd40]
pc: c0000000000404fc: restore_gprs+0xc0/0x148
lr: 0000000000000000
sp: 0
msr: 9000000100201030
current = 0xc000001dd1417c30
paca = 0xc00000000fe00800 softe: 0 irq_happened: 0x01
pid = 0, comm = swapper/2
WARNING: exception is not recoverable, can't continue
The below fixes this by flushing the TM state before we copy the task_struct to
the clone. To do this we go through the tmreclaim patch, which removes the
checkpointed registers from the CPU and transitions the CPU out of TM suspend
mode. Hence we need to call tmrechkpt after to restore the checkpointed state
and the TM mode for the current task.
To make this fail from userspace is simply:
tbegin
li r0, 2
sc
<boom>
Kudos to Adhemerval Zanella Neto for finding this.
Signed-off-by: Michael Neuling <mikey@neuling.org>
cc: Adhemerval Zanella Neto <azanella@br.ibm.com>
cc: stable@vger.kernel.org
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This fixes a logic error that caused a failure to update the hw breakpoint
registers when not using the hw-breakpoint interface.
Signed-off-by: Andreas Schwab <schwab@linux-m68k.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
