Back when I added -Werror in commit ba55bd74360e ("powerpc: Add
configurable -Werror for arch/powerpc") I did it by adding it to most
of the arch Makefiles.

At the time we excluded math-emu, because apparently it didn't build
cleanly. But that seems to have been fixed somewhere in the interim.

So move the -Werror addition to the top-level of the arch, this saves
us from repeating it in every Makefile and means we won't forget to
add it to any new sub-dirs.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

The powerpc kernel uses setjmp which causes a warning when building
with clang:

  In file included from arch/powerpc/xmon/xmon.c:51:
  ./arch/powerpc/include/asm/setjmp.h:15:13: error: declaration of
  built-in function 'setjmp' requires inclusion of the header <setjmp.h>
        [-Werror,-Wbuiltin-requires-header]
  extern long setjmp(long *);
              ^
  ./arch/powerpc/include/asm/setjmp.h:16:13: error: declaration of
  built-in function 'longjmp' requires inclusion of the header <setjmp.h>
        [-Werror,-Wbuiltin-requires-header]
  extern void longjmp(long *, long);
              ^

This *is* the header and we're not using the built-in setjump but
rather the one in arch/powerpc/kernel/misc.S. As the compiler warning
does not make sense, it for the files where setjmp is used.

Signed-off-by: Joel Stanley <joel@jms.id.au>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
[mpe: Move subdir-ccflags in xmon/Makefile to not clobber -Werror]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

This functionality was tentatively added in the past
(commit 6533b7c16ee5 ("powerpc: Initial stack protector
(-fstack-protector) support")) but had to be reverted
(commit f2574030b0e3 ("powerpc: Revert the initial stack
protector support") because of GCC implementing it differently
whether it had been built with libc support or not.

Now, GCC offers the possibility to manually set the
stack-protector mode (global or tls) regardless of libc support.

This time, the patch selects HAVE_STACKPROTECTOR only if
-mstack-protector-guard=tls is supported by GCC.

On PPC32, as register r2 points to current task_struct at
all time, the stack_canary located inside task_struct can be
used directly by using the following GCC options:
-mstack-protector-guard=tls
-mstack-protector-guard-reg=r2
-mstack-protector-guard-offset=offsetof(struct task_struct, stack_canary))

The protector is disabled for prom_init and bootx_init as
it is too early to handle it properly.

 $ echo CORRUPT_STACK > /sys/kernel/debug/provoke-crash/DIRECT
[  134.943666] Kernel panic - not syncing: stack-protector: Kernel stack is corrupted in: lkdtm_CORRUPT_STACK+0x64/0x64
[  134.943666]
[  134.955414] CPU: 0 PID: 283 Comm: sh Not tainted 4.18.0-s3k-dev-12143-ga3272be41209 #835
[  134.963380] Call Trace:
[  134.965860] [c6615d60] [c001f76c] panic+0x118/0x260 (unreliable)
[  134.971775] [c6615dc0] [c001f654] panic+0x0/0x260
[  134.976435] [c6615dd0] [c032c368] lkdtm_CORRUPT_STACK_STRONG+0x0/0x64
[  134.982769] [c6615e00] [ffffffff] 0xffffffff

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

In Makefiles if we're testing a CONFIG_FOO symbol for equality with 'y'
we can instead just use ifdef. The latter reads easily, so convert to
it where possible.

Signed-off-by: Rodrigo R. Galvao <rosattig@linux.vnet.ibm.com>
Reviewed-by: Mauro S. M. Rodrigues <maurosr@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

Add a config symbol to encode which platforms support the
barrier_nospec speculation barrier. Currently this is just Book3S 64
but we will add Book3E in a future patch.

Signed-off-by: Diana Craciun <diana.craciun@nxp.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

Pull powerpc updates from Michael Ellerman:
 "Notable changes:

   - Support for 4PB user address space on 64-bit, opt-in via mmap().

   - Removal of POWER4 support, which was accidentally broken in 2016
     and no one noticed, and blocked use of some modern instructions.

   - Workarounds so that the hypervisor can enable Transactional Memory
     on Power9.

   - A series to disable the DAWR (Data Address Watchpoint Register) on
     Power9.

   - More information displayed in the meltdown/spectre_v1/v2 sysfs
     files.

   - A vpermxor (Power8 Altivec) implementation for the raid6 Q
     Syndrome.

   - A big series to make the allocation of our pacas (per cpu area),
     kernel page tables, and per-cpu stacks NUMA aware when using the
     Radix MMU on Power9.

  And as usual many fixes, reworks and cleanups.

  Thanks to: Aaro Koskinen, Alexandre Belloni, Alexey Kardashevskiy,
  Alistair Popple, Andy Shevchenko, Aneesh Kumar K.V, Anshuman Khandual,
  Balbir Singh, Benjamin Herrenschmidt, Christophe Leroy, Christophe
  Lombard, Cyril Bur, Daniel Axtens, Dave Young, Finn Thain, Frederic
  Barrat, Gustavo Romero, Horia Geantă, Jonathan Neuschäfer, Kees Cook,
  Larry Finger, Laurent Dufour, Laurent Vivier, Logan Gunthorpe,
  Madhavan Srinivasan, Mark Greer, Mark Hairgrove, Markus Elfring,
  Mathieu Malaterre, Matt Brown, Matt Evans, Mauricio Faria de Oliveira,
  Michael Neuling, Naveen N. Rao, Nicholas Piggin, Paul Mackerras,
  Philippe Bergheaud, Ram Pai, Rob Herring, Sam Bobroff, Segher
  Boessenkool, Simon Guo, Simon Horman, Stewart Smith, Sukadev
  Bhattiprolu, Suraj Jitindar Singh, Thiago Jung Bauermann, Vaibhav
  Jain, Vaidyanathan Srinivasan, Vasant Hegde, Wei Yongjun"

* tag 'powerpc-4.17-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (207 commits)
  powerpc/64s/idle: Fix restore of AMOR on POWER9 after deep sleep
  powerpc/64s: Fix POWER9 DD2.2 and above in cputable features
  powerpc/64s: Fix pkey support in dt_cpu_ftrs, add CPU_FTR_PKEY bit
  powerpc/64s: Fix dt_cpu_ftrs to have restore_cpu clear unwanted LPCR bits
  Revert "powerpc/64s/idle: POWER9 ESL=0 stop avoid save/restore overhead"
  powerpc: iomap.c: introduce io{read|write}64_{lo_hi|hi_lo}
  powerpc: io.h: move iomap.h include so that it can use readq/writeq defs
  cxl: Fix possible deadlock when processing page faults from cxllib
  powerpc/hw_breakpoint: Only disable hw breakpoint if cpu supports it
  powerpc/mm/radix: Update command line parsing for disable_radix
  powerpc/mm/radix: Parse disable_radix commandline correctly.
  powerpc/mm/hugetlb: initialize the pagetable cache correctly for hugetlb
  powerpc/mm/radix: Update pte fragment count from 16 to 256 on radix
  powerpc/mm/keys: Update documentation and remove unnecessary check
  powerpc/64s/idle: POWER9 ESL=0 stop avoid save/restore overhead
  powerpc/64s/idle: Consolidate power9_offline_stop()/power9_idle_stop()
  powerpc/powernv: Always stop secondaries before reboot/shutdown
  powerpc: hard disable irqs in smp_send_stop loop
  powerpc: use NMI IPI for smp_send_stop
  powerpc/powernv: Fix SMT4 forcing idle code
  ...

This commit adds security feature flags to reflect the settings we
receive from firmware regarding Spectre/Meltdown mitigations.

The feature names reflect the names we are given by firmware on bare
metal machines. See the hostboot source for details.

Arguably these could be firmware features, but that then requires them
to be read early in boot so they're available prior to asm feature
patching, but we don't actually want to use them for patching. We may
also want to dynamically update them in future, which would be
incompatible with the way firmware features work (at the moment at
least). So for now just make them separate flags.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

Incremental linking is gone, so rename built-in.o to built-in.a, which
is the usual extension for archive files.

This patch does two things, first is a simple search/replace:

git grep -l 'built-in\.o' | xargs sed -i 's/built-in\.o/built-in\.a/g'

The second is to invert nesting of nested text manipulations to avoid
filtering built-in.a out from libs-y2:

-libs-y2 := $(filter-out %.a, $(patsubst %/, %/built-in.a, $(libs-y)))
+libs-y2 := $(patsubst %/, %/built-in.a, $(filter-out %.a, $(libs-y)))

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

Pull powerpc updates from Michael Ellerman:
 "A bit of a small release, I suspect in part due to me travelling for
  KS. But my backlog of patches to review is smaller than usual, so I
  think in part folks just didn't send as much this cycle.

  Non-highlights:

   - Five fixes for the >128T address space handling, both to fix bugs
     in our implementation and to bring the semantics exactly into line
     with x86.

  Highlights:

   - Support for a new OPAL call on bare metal machines which gives us a
     true NMI (ie. is not masked by MSR[EE]=0) for debugging etc.

   - Support for Power9 DD2 in the CXL driver.

   - Improvements to machine check handling so that uncorrectable errors
     can be reported into the generic memory_failure() machinery.

   - Some fixes and improvements for VPHN, which is used under PowerVM
     to notify the Linux partition of topology changes.

   - Plumbing to enable TM (transactional memory) without suspend on
     some Power9 processors (PPC_FEATURE2_HTM_NO_SUSPEND).

   - Support for emulating vector loads form cache-inhibited memory, on
     some Power9 revisions.

   - Disable the fast-endian switch "syscall" by default (behind a
     CONFIG), we believe it has never had any users.

   - A major rework of the API drivers use when initiating and waiting
     for long running operations performed by OPAL firmware, and changes
     to the powernv_flash driver to use the new API.

   - Several fixes for the handling of FP/VMX/VSX while processes are
     using transactional memory.

   - Optimisations of TLB range flushes when using the radix MMU on
     Power9.

   - Improvements to the VAS facility used to access coprocessors on
     Power9, and related improvements to the way the NX crypto driver
     handles requests.

   - Implementation of PMEM_API and UACCESS_FLUSHCACHE for 64-bit.

  Thanks to: Alexey Kardashevskiy, Alistair Popple, Allen Pais, Andrew
  Donnellan, Aneesh Kumar K.V, Arnd Bergmann, Balbir Singh, Benjamin
  Herrenschmidt, Breno Leitao, Christophe Leroy, Christophe Lombard,
  Cyril Bur, Frederic Barrat, Gautham R. Shenoy, Geert Uytterhoeven,
  Guilherme G. Piccoli, Gustavo Romero, Haren Myneni, Joel Stanley,
  Kamalesh Babulal, Kautuk Consul, Markus Elfring, Masami Hiramatsu,
  Michael Bringmann, Michael Neuling, Michal Suchanek, Naveen N. Rao,
  Nicholas Piggin, Oliver O'Halloran, Paul Mackerras, Pedro Miraglia
  Franco de Carvalho, Philippe Bergheaud, Sandipan Das, Seth Forshee,
  Shriya, Stephen Rothwell, Stewart Smith, Sukadev Bhattiprolu, Tyrel
  Datwyler, Vaibhav Jain, Vaidyanathan Srinivasan, and William A.
  Kennington III"

* tag 'powerpc-4.15-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (151 commits)
  powerpc/64s: Fix Power9 DD2.0 workarounds by adding DD2.1 feature
  powerpc/64s: Fix masking of SRR1 bits on instruction fault
  powerpc/64s: mm_context.addr_limit is only used on hash
  powerpc/64s/radix: Fix 128TB-512TB virtual address boundary case allocation
  powerpc/64s/hash: Allow MAP_FIXED allocations to cross 128TB boundary
  powerpc/64s/hash: Fix fork() with 512TB process address space
  powerpc/64s/hash: Fix 128TB-512TB virtual address boundary case allocation
  powerpc/64s/hash: Fix 512T hint detection to use >= 128T
  powerpc: Fix DABR match on hash based systems
  powerpc/signal: Properly handle return value from uprobe_deny_signal()
  powerpc/fadump: use kstrtoint to handle sysfs store
  powerpc/lib: Implement UACCESS_FLUSHCACHE API
  powerpc/lib: Implement PMEM API
  powerpc/powernv/npu: Don't explicitly flush nmmu tlb
  powerpc/powernv/npu: Use flush_all_mm() instead of flush_tlb_mm()
  powerpc/powernv/idle: Round up latency and residency values
  powerpc/kprobes: refactor kprobe_lookup_name for safer string operations
  powerpc/kprobes: Blacklist emulate_update_regs() from kprobes
  powerpc/kprobes: Do not disable interrupts for optprobes and kprobes_on_ftrace
  powerpc/kprobes: Disable preemption before invoking probe handler for optprobes
  ...