Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

all architectures converted
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

We have a big list of selects under CONFIG_PPC, and currently they're
completely unsorted. This means people tend to add new selects at the
bottom of the list, and so two commits which both add a new select will
often conflict.

Instead sort it alphabetically. This is nicer in and of itself, but also
means two commits that add a new select will have a greater chance of
not conflicting.

Add a note at the top and bottom asking people to keep it sorted.

And while we're here pad out the 'if' expressions to make them stand
out.
Suggested-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

The final paragraph of the help text is reversed. We want to enable
this option by default, and disable it if the toolchain has a working
-mprofile-kernel.

Fixes: 8c50b72a ("powerpc/ftrace: Add Kconfig & Make glue for mprofile-kernel")
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

Current infrastructure of kprobe uses the unconditional trap instruction
to probe a running kernel. Optprobe allows kprobe to replace the trap
with a branch instruction to a detour buffer. Detour buffer contains
instructions to create an in memory pt_regs. Detour buffer also has a
call to optimized_callback() which in turn call the pre_handler(). After
the execution of the pre-handler, a call is made for instruction
emulation. The NIP is determined in advanced through dummy instruction
emulation and a branch instruction is created to the NIP at the end of
the trampoline.

To address the limitation of branch instruction in POWER architecture,
detour buffer slot is allocated from a reserved area. For the time
being, 64KB is reserved in memory for this purpose.

Instructions which can be emulated using analyse_instr() are the
candidates for optimization. Before optimization ensure that the address
range between the detour buffer allocated and the instruction being
probed is within +/- 32MB.
Signed-off-by: Anju T Sudhakar <anju@linux.vnet.ibm.com>
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

The modversion symbol CRCs are emitted as ELF symbols, which allows us
to easily populate the kcrctab sections by relying on the linker to
associate each kcrctab slot with the correct value.

This has a couple of downsides:

 - Given that the CRCs are treated as memory addresses, we waste 4 bytes
   for each CRC on 64 bit architectures,

 - On architectures that support runtime relocation, a R_<arch>_RELATIVE
   relocation entry is emitted for each CRC value, which identifies it
   as a quantity that requires fixing up based on the actual runtime
   load offset of the kernel. This results in corrupted CRCs unless we
   explicitly undo the fixup (and this is currently being handled in the
   core module code)

 - Such runtime relocation entries take up 24 bytes of __init space
   each, resulting in a x8 overhead in [uncompressed] kernel size for
   CRCs.

Switching to explicit 32 bit values on 64 bit architectures fixes most
of these issues, given that 32 bit values are not treated as quantities
that require fixing up based on the actual runtime load offset.  Note
that on some ELF64 architectures [such as PPC64], these 32-bit values
are still emitted as [absolute] runtime relocatable quantities, even if
the value resolves to a build time constant.  Since relative relocations
are always resolved at build time, this patch enables MODULE_REL_CRCS on
powerpc when CONFIG_RELOCATABLE=y, which turns the absolute CRC
references into relative references into .rodata where the actual CRC
value is stored.

So redefine all CRC fields and variables as u32, and redefine the
__CRC_SYMBOL() macro for 64 bit builds to emit the CRC reference using
inline assembler (which is necessary since 64-bit C code cannot use
32-bit types to hold memory addresses, even if they are ultimately
resolved using values that do not exceed 0xffffffff).  To avoid
potential problems with legacy 32-bit architectures using legacy
toolchains, the equivalent C definition of the kcrctab entry is retained
for 32-bit architectures.

Note that this mostly reverts commit d4703aef ("module: handle ppc64
relocating kcrctabs when CONFIG_RELOCATABLE=y")
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Enable support for GCC plugins on powerpc.

Add an additional version check in gcc-plugins-check to advise users to
upgrade to gcc 5.2+ on powerpc to avoid issues with header files (gcc <=
4.6) or missing copies of rs6000-cpus.def (4.8 to 5.1 on 64-bit
targets).
Signed-off-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

We added support for HAVE_CONTEXT_TRACKING, but placed the option inside
PPC_PSERIES.

This has the undesirable effect that NO_HZ_FULL can be enabled on a
kernel with both powernv and pseries support, but cannot on a kernel
with powernv only support.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

This patch implements HW breakpoint on the 8xx. The 8xx has
capability to manage HW breakpoints, which is slightly different
than BOOK3S:
1/ The breakpoint match doesn't trigger a DSI exception but a
dedicated data breakpoint exception.
2/ The breakpoint happens after the instruction has completed,
no need to single step or emulate the instruction,
3/ Matched address is not set in DAR but in BAR,
4/ DABR register doesn't exist, instead we have registers
LCTRL1, LCTRL2 and CMPx registers,
5/ The match on one comparator is not on a double word but
on a single word.

The patch does:
1/ Prepare the dedicated registers in call to __set_dabr(). In order
to emulate the double word handling of BOOK3S, comparator E is set to
DABR address value and comparator F to address + 4. Then breakpoint 1
is set to match comparator E or F,
2/ Skip the singlestepping stage when compiled for CONFIG_PPC_8xx,
3/ Implement the exception. In that exception, the matched address
is taken from SPRN_BAR and manage as if it was from SPRN_DAR.
4/ I/D TLB error exception routines perform a tlbie on bad TLBs. That
tlbie triggers the breakpoint exception when performed on the
breakpoint address. For this reason, the routine returns if the match
is from one of those two tlbie.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Scott Wood <oss@buserror.net>

BOOK3S also has DABR register and capability to handle data
breakpoints, so this patch enable it on all BOOK3S, not only 64 bits.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Scott Wood <oss@buserror.net>

Currently we have optimized hand-coded assembly checksum routines for
big-endian 64-bit systems, but for little-endian we use the generic C
routines. This modifies the optimized routines to work for
little-endian. With this, we no longer need to enable
CONFIG_GENERIC_CSUM. This also fixes a couple of comments in
checksum_64.S so they accurately reflect what the associated instruction
does.
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
[mpe: Use the more common __BIG_ENDIAN__]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

Unfortunately the stack protector support we merged recently only works
on some toolchains. If the toolchain is built without glibc support
everything works fine, but if glibc is built then it leads to a panic
at boot.

The solution is not rc5 material, so revert the support for now. This
reverts commits:

6533b7c1 ("powerpc: Initial stack protector (-fstack-protector) support")
902e06eb ("powerpc/32: Change the stack protector canary value per task")

Fixes: 6533b7c1 ("powerpc: Initial stack protector (-fstack-protector) support")
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

Patch series "ima: carry the measurement list across kexec", v8.

The TPM PCRs are only reset on a hard reboot.  In order to validate a
TPM's quote after a soft reboot (eg.  kexec -e), the IMA measurement
list of the running kernel must be saved and then restored on the
subsequent boot, possibly of a different architecture.

The existing securityfs binary_runtime_measurements file conveniently
provides a serialized format of the IMA measurement list.  This patch
set serializes the measurement list in this format and restores it.

Up to now, the binary_runtime_measurements was defined as architecture
native format.  The assumption being that userspace could and would
handle any architecture conversions.  With the ability of carrying the
measurement list across kexec, possibly from one architecture to a
different one, the per boot architecture information is lost and with it
the ability of recalculating the template digest hash.  To resolve this
problem, without breaking the existing ABI, this patch set introduces
the boot command line option "ima_canonical_fmt", which is arbitrarily
defined as little endian.

The need for this boot command line option will be limited to the
existing version 1 format of the binary_runtime_measurements.
Subsequent formats will be defined as canonical format (eg.  TPM 2.0
support for larger digests).

A simplified method of Thiago Bauermann's "kexec buffer handover" patch
series for carrying the IMA measurement list across kexec is included in
this patch set.  The simplified method requires all file measurements be
taken prior to executing the kexec load, as subsequent measurements will
not be carried across the kexec and restored.

This patch (of 10):

The IMA kexec buffer allows the currently running kernel to pass the
measurement list via a kexec segment to the kernel that will be kexec'd.
The second kernel can check whether the previous kernel sent the buffer
and retrieve it.

This is the architecture-specific part which enables IMA to receive the
measurement list passed by the previous kernel.  It will be used in the
next patch.

The change in machine_kexec_64.c is to factor out the logic of removing
an FDT memory reservation so that it can be used by remove_ima_buffer.

Link: http://lkml.kernel.org/r/1480554346-29071-2-git-send-email-zohar@linux.vnet.ibm.comSigned-off-by: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Andreas Steffen <andreas.steffen@strongswan.org>
Cc: Dmitry Kasatkin <dmitry.kasatkin@gmail.com>
Cc: Josh Sklar <sklar@linux.vnet.ibm.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Stewart Smith <stewart@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

This is used in poison.h to offset poison values so that they don't
point directly into user space.

The value we choose sits roughly between user and kernel space, which
means on their own the poison values don't point anywhere useful. If an
attacker can cause an access at some offset from the poison value then
we may still be in trouble, but by putting the poison values between
user and kernel space we maximise the required size of that offset.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

Define the Kconfig symbol so that the kexec_file_load() code can be
built, and wire up the syscall so that it can be called.
Signed-off-by: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

Commit 2965faa5 ("kexec: split kexec_load syscall from kexec core
code") introduced CONFIG_KEXEC_CORE so that CONFIG_KEXEC means whether
the kexec_load system call should be compiled-in and CONFIG_KEXEC_FILE
means whether the kexec_file_load system call should be compiled-in.
These options can be set independently from each other.

Since until now powerpc only supported kexec_load, CONFIG_KEXEC and
CONFIG_KEXEC_CORE were synonyms. That is not the case anymore, so we
need to make a distinction. Almost all places where CONFIG_KEXEC was
being used should be using CONFIG_KEXEC_CORE instead, since
kexec_file_load also needs that code compiled in.
Signed-off-by: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

Partialy copied from commit c743f380 ("ARM: initial stack protector
(-fstack-protector) support")

This is the very basic stuff without the changing canary upon
task switch yet.  Just the Kconfig option and a constant canary
value initialized at boot time.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

Add an option to use thin archives to build the kernel.
Thin archives are explained in commit a5967db9 ("kbuild: allow
architectures to use thin archives instead of ld -r").

This is a gradual way to introduce the option to testers.

Some change to the way we invoke ar is required so it can be used
by scripts/link-vmlinux.sh.
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
[mpe: Make it an explicit option not dependant on COMPILE_TEST]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

Only s390 and powerpc have hardware facilities allowing to measure
cputimes scaled by frequency. On all other architectures
utimescaled/stimescaled are equal to utime/stime (however they are
accounted separately).

Remove {u,s}timescaled accounting on all architectures except
powerpc and s390, where those values are explicitly accounted
in the proper places.
Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Michael Neuling <mikey@neuling.org>
Cc: Paul Mackerras <paulus@ozlabs.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20161031162143.GB12646@redhat.comSigned-off-by: Ingo Molnar <mingo@kernel.org>

This adds a config option that can help exercise the case when
the kernel is not running at PAGE_OFFSET.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Balbir Singh <bsingharora@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

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

This came to light when implementing native 64-bit atomics for ARCv2.

The atomic64 self-test code uses CONFIG_ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
to check whether atomic64_dec_if_positive() is available.  It seems it
was needed when not every arch defined it.  However as of current code
the Kconfig option seems needless

 - for CONFIG_GENERIC_ATOMIC64 it is auto-enabled in lib/Kconfig and a
   generic definition of API is present lib/atomic64.c
 - arches with native 64-bit atomics select it in arch/*/Kconfig and
   define the API in their headers

So I see no point in keeping the Kconfig option

Compile tested for:
 - blackfin (CONFIG_GENERIC_ATOMIC64)
 - x86 (!CONFIG_GENERIC_ATOMIC64)
 - ia64

Link: http://lkml.kernel.org/r/1473703083-8625-3-git-send-email-vgupta@synopsys.comSigned-off-by: Vineet Gupta <vgupta@synopsys.com>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
Cc: Helge Deller <deller@gmx.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Chris Metcalf <cmetcalf@mellanox.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Zhaoxiu Zeng <zhaoxiu.zeng@gmail.com>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Ming Lin <ming.l@ssi.samsung.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Borislav Petkov <bp@suse.de>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

POWER8 handles unaligned accesses in little endian mode, but commit
0b5e6661 ("powerpc: Don't set HAVE_EFFICIENT_UNALIGNED_ACCESS on
little endian builds") disabled it for all.

The issue with unaligned little endian accesses is specific to POWER7,
so update the Kconfig check to match. Using the stat() testcase from
commit a75c380c ("powerpc: Enable DCACHE_WORD_ACCESS on ppc64le"),
performance improves 15% on POWER8.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

Most architectures allow the compression algorithm used to produced the
vmlinuz image to be selected as a kernel config option. In preperation
for supporting algorithms other than gzip in the powerpc boot wrapper
the makefile needs to be modified to use these config options.
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

For hugetlb to work with 4K page size, we need MAX_ORDER to be 13 or
more. When switching from a 64K page size to 4K linux page size using
make oldconfig, we end up with a CONFIG_FORCE_MAX_ZONEORDER value of 9.
This results in a 16M hugepage beiing considered as a gigantic huge page
which in turn results in failure to setup hugepages if gigantic hugepage
support is not enabled.

This also results in kernel crash with 4K radix configuration. We
hit the below BUG_ON on radix:

  kernel BUG at mm/huge_memory.c:364!
  Oops: Exception in kernel mode, sig: 5 [#1]
  SMP NR_CPUS=2048 NUMA PowerNV
  CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.8.0-rc1-00006-gbae9cc6 #1
  task: c0000000f1af8000 task.stack: c0000000f1aec000
  NIP: c000000000c5fa0c LR: c000000000c5f9d8 CTR: c000000000c5f9a4
  REGS: c0000000f1aef920 TRAP: 0700   Not tainted (4.8.0-rc1-00006-gbae9cc6)
  MSR: 9000000102029033 <SF,HV,VEC,EE,ME,IR,DR,RI,LE,TM[E]>  CR: 24000844  XER: 00000000
  CFAR: c000000000c5f9e0 SOFTE: 1
  ....
  NIP [c000000000c5fa0c] hugepage_init+0x68/0x238
  LR [c000000000c5f9d8] hugepage_init+0x34/0x238

Fixes: a7ee5395 ("powerpc/Kconfig: Update config option based on page size")
Cc: stable@vger.kernel.org # v4.7+
Reported-by: Santhosh <santhog4@linux.vnet.ibm.com>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Acked-by: Balbir Singh <bsingharora@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

Commit 2578bfae ("[POWERPC] Create and use CONFIG_WORD_SIZE") added
CONFIG_WORD_SIZE, and suggests that other arches were going to do
likewise.

But that never happened, powerpc is the only architecture which uses it.

So switch to using a simple make variable, BITS, like x86, sh, sparc and
tile. It is also easier to spell and simpler, avoiding any confusion
about whether it's defined due to ordering of make vs kconfig.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

Enables CONFIG_HARDENED_USERCOPY checks on powerpc.

Based on code from PaX and grsecurity.
Signed-off-by: Kees Cook <keescook@chromium.org>
Tested-by: Michael Ellerman <mpe@ellerman.id.au>

This patch provides the necessary infrastructure to allow drivers
to be automatically loaded via udev. It implements the minimum
required to be able to use module_cpu_feature_match() to trigger
the GENERIC_CPU_AUTOPROBE mechanisms.

The features exposed are a mirror of the cpu_user_features
(converted to an offset from a mask). This decision was made to
ensure that the behavior between features for module loading and
userspace are consistent.
Signed-off-by: Alastair D'Silva <alastair@d-silva.org>
[mpe: Only define the bits we currently need]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

It is seldom used in the kernel code and can be easily replaced by
either RELOCATABLE or PPC32. So there is no reason to keep a separate
kernel option for this.
Signed-off-by: Kevin Hao <haokexin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

It makes no sense to keep two separate RELOCATABLE config entries for
ppc32 and ppc64 respectively. Merge them into one and move it to a
common place.
Signed-off-by: Kevin Hao <haokexin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

In the current code, the RELOCATABLE will be forcedly enabled when
enabling CRASH_DUMP. But for ppc32, the RELOCABLE also depend on
ADVANCED_OPTIONS and select NONSTATIC_KERNEL. This will cause the
following build error when CRASH_DUMP=y && ADVANCED_OPTIONS=n because
the select of NONSTATIC_KERNEL doesn't take effect.

  arch/powerpc/include/asm/io.h: In function 'virt_to_phys':
  arch/powerpc/include/asm/page.h:113:26: error: 'virt_phys_offset' undeclared (first use in this function)
   #define VIRT_PHYS_OFFSET virt_phys_offset
                          ^
It doesn't have any strong reasons to make the RELOCATABLE depend on
ADVANCED_OPTIONS. So remove this dependency to fix this issue.
Signed-off-by: Kevin Hao <haokexin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

CONFIG_PIN_TLB maps IMMR area and the first 24 Mbytes of memory.
In some circunstances it might be more interesting to not map
IMMR but map 32 Mbytes of memory instead.

Therefore we add config option CONFIG_PIN_TLB_IMMR to select if
IMMR shall be pinned or not, hence whether we pin 24 or 32 Mbytes of RAM
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Scott Wood <oss@buserror.net>

This patch provides VIRT_CPU_ACCOUTING to PPC32 architecture.
PPC32 doesn't have the PACA structure, so we use the task_info
structure to store the accounting data.

In order to reuse on PPC32 the PPC64 functions, all u64 data has
been replaced by 'unsigned long' so that it is u32 on PPC32 and
u64 on PPC64
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Scott Wood <oss@buserror.net>

PPC64 eBPF JIT compiler.

Enable with:
  echo 1 > /proc/sys/net/core/bpf_jit_enable
or
  echo 2 > /proc/sys/net/core/bpf_jit_enable

... to see the generated JIT code. This can further be processed with
tools/net/bpf_jit_disasm.

With CONFIG_TEST_BPF=m and 'modprobe test_bpf':

 test_bpf: Summary: 305 PASSED, 0 FAILED, [297/297 JIT'ed]

... on both ppc64 BE and LE.

The details of the approach are documented through various comments in
the code.
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

Classic BPF JIT was never ported completely to work on little endian
powerpc. However, it can be enabled and will crash the system when used.
As such, disable use of BPF JIT on ppc64le.

Fixes: 7c105b63 ("powerpc: Add CONFIG_CPU_LITTLE_ENDIAN kernel config option.")
Reported-by: Thadeu Lima de Souza Cascardo <cascardo@redhat.com>
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Acked-by: Thadeu Lima de Souza Cascardo <cascardo@redhat.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

This replaces:

- "select ARCH_REQUIRE_GPIOLIB" with "select GPIOLIB" as this can
  now be selected directly.

- "select ARCH_WANT_OPTIONAL_GPIOLIB" with no dependency: GPIOLIB
  is now selectable by everyone, so we need not declare our
  intent to select it.

When ordering the symbols the following rationale was used:
if the selects were in alphabetical order, I moved select GPIOLIB
to be in alphabetical order, but if the selects were not
maintained in alphabetical order, I just replaced
"select ARCH_REQUIRE_GPIOLIB" with "select GPIOLIB".

Cc: Michael Büsch <m@bues.ch>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: linuxppc-dev@lists.ozlabs.org
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

printk() takes some locks and could not be used a safe way in NMI
context.

The chance of a deadlock is real especially when printing stacks from
all CPUs.  This particular problem has been addressed on x86 by the
commit a9edc880 ("x86/nmi: Perform a safe NMI stack trace on all
CPUs").

The patchset brings two big advantages.  First, it makes the NMI
backtraces safe on all architectures for free.  Second, it makes all NMI
messages almost safe on all architectures (the temporary buffer is
limited.  We still should keep the number of messages in NMI context at
minimum).

Note that there already are several messages printed in NMI context:
WARN_ON(in_nmi()), BUG_ON(in_nmi()), anything being printed out from MCE
handlers.  These are not easy to avoid.

This patch reuses most of the code and makes it generic.  It is useful
for all messages and architectures that support NMI.

The alternative printk_func is set when entering and is reseted when
leaving NMI context.  It queues IRQ work to copy the messages into the
main ring buffer in a safe context.

__printk_nmi_flush() copies all available messages and reset the buffer.
Then we could use a simple cmpxchg operations to get synchronized with
writers.  There is also used a spinlock to get synchronized with other
flushers.

We do not longer use seq_buf because it depends on external lock.  It
would be hard to make all supported operations safe for a lockless use.
It would be confusing and error prone to make only some operations safe.

The code is put into separate printk/nmi.c as suggested by Steven
Rostedt.  It needs a per-CPU buffer and is compiled only on
architectures that call nmi_enter().  This is achieved by the new
HAVE_NMI Kconfig flag.

The are MN10300 and Xtensa architectures.  We need to clean up NMI
handling there first.  Let's do it separately.

The patch is heavily based on the draft from Peter Zijlstra, see

  https://lkml.org/lkml/2015/6/10/327

[arnd@arndb.de: printk-nmi: use %zu format string for size_t]
[akpm@linux-foundation.org: min_t->min - all types are size_t here]
Signed-off-by: Petr Mladek <pmladek@suse.com>
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Suggested-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Jan Kara <jack@suse.cz>
Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>	[arm part]
Cc: Daniel Thompson <daniel.thompson@linaro.org>
Cc: Jiri Kosina <jkosina@suse.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: David Miller <davem@davemloft.net>
Cc: Daniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

This dependency led to kconfig errors when MTD_NAND_FSL_ELBC was
enabled, which selects FSL_LBC, in the absence of FSL_SOC, as reported
in http://patchwork.ozlabs.org/patch/564405/

It was originally suggested to add an FSL_SOC dependency to
MTD_NAND_FSL_ELBC, but the FSL_SOC symbol has been a growing problem
due to hardware being shared between PPC and ARM SoCs.  Even though
eLBC isn't found on ARM SoCs (the newer IFC is used instead), I don't
want to expand the use of FSL_SOC for things other than functions
exported by fsl_soc.c.  In particular, it would be odd to add it to
MTD_NAND_FSL_ELBC and then remove it from MTD_NAND_FSL_IFC.

Removing artificial dependencies also helps get compile-test exposure
via randconfig, allyesconfig, etc.
Reported-by: Brian Norris <computersforpeace@gmail.com>
Cc: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: Scott Wood <oss@buserror.net>

Split the HAVE_BPF_JIT into two for distinguishing cBPF and eBPF JITs.

Current cBPF ones:

  # git grep -n HAVE_CBPF_JIT arch/
  arch/arm/Kconfig:44:    select HAVE_CBPF_JIT
  arch/mips/Kconfig:18:   select HAVE_CBPF_JIT if !CPU_MICROMIPS
  arch/powerpc/Kconfig:129:       select HAVE_CBPF_JIT
  arch/sparc/Kconfig:35:  select HAVE_CBPF_JIT

Current eBPF ones:

  # git grep -n HAVE_EBPF_JIT arch/
  arch/arm64/Kconfig:61:  select HAVE_EBPF_JIT
  arch/s390/Kconfig:126:  select HAVE_EBPF_JIT if PACK_STACK && HAVE_MARCH_Z196_FEATURES
  arch/x86/Kconfig:94:    select HAVE_EBPF_JIT                    if X86_64

Later code also needs this facility to check for eBPF JITs.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>