Mostly cosmetic changes:

- Group common stack pointer code at the top
- Simplify the first frame logic
- Code stackframe iteration into for...loop construct
- Check for trace->nr_entries overflow before adding any into the array
Suggested-by: Nicolai Stange <nstange@suse.de>
Signed-off-by: Joe Lawrence <joe.lawrence@redhat.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

The bottom-most stack frame (the first to be unwound) may be largely
uninitialized, for the "Power Architecture 64-Bit ELF V2 ABI" only
requires its backchain pointer to be set.

The reliable stack tracer should be careful when verifying this frame:
skip checks on STACK_FRAME_LR_SAVE and STACK_FRAME_MARKER offsets that
may contain uninitialized residual data.

Fixes: df78d3f6 ("powerpc/livepatch: Implement reliable stack tracing for the consistency model")
Signed-off-by: Joe Lawrence <joe.lawrence@redhat.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

Make the HAVE_RELIABLE_STACKTRACE Kconfig option depend on
PPC_BOOK3S_64 for documentation purposes. Before this patch, it
depended on PPC64 && CPU_LITTLE_ENDIAN and because CPU_LITTLE_ENDIAN
implies PPC_BOOK3S_64, there's no functional change here.
Signed-off-by: Nicolai Stange <nstange@suse.de>
Signed-off-by: Joe Lawrence <joe.lawrence@redhat.com>
[mpe: Split out of larger patch]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

The ppc64 specific implementation of the reliable stacktracer,
save_stack_trace_tsk_reliable(), bails out and reports an "unreliable
trace" whenever it finds an exception frame on the stack. Stack frames
are classified as exception frames if the STACK_FRAME_REGS_MARKER
magic, as written by exception prologues, is found at a particular
location.

However, as observed by Joe Lawrence, it is possible in practice that
non-exception stack frames can alias with prior exception frames and
thus, that the reliable stacktracer can find a stale
STACK_FRAME_REGS_MARKER on the stack. It in turn falsely reports an
unreliable stacktrace and blocks any live patching transition to
finish. Said condition lasts until the stack frame is
overwritten/initialized by function call or other means.

In principle, we could mitigate this by making the exception frame
classification condition in save_stack_trace_tsk_reliable() stronger:
in addition to testing for STACK_FRAME_REGS_MARKER, we could also take
into account that for all exceptions executing on the kernel stack
  - their stack frames's backlink pointers always match what is saved
    in their pt_regs instance's ->gpr[1] slot and that
  - their exception frame size equals STACK_INT_FRAME_SIZE, a value
    uncommonly large for non-exception frames.

However, while these are currently true, relying on them would make
the reliable stacktrace implementation more sensitive towards future
changes in the exception entry code. Note that false negatives, i.e.
not detecting exception frames, would silently break the live patching
consistency model.

Furthermore, certain other places (diagnostic stacktraces, perf, xmon)
rely on STACK_FRAME_REGS_MARKER as well.

Make the exception exit code clear the on-stack
STACK_FRAME_REGS_MARKER for those exceptions running on the "normal"
kernel stack and returning to kernelspace: because the topmost frame
is ignored by the reliable stack tracer anyway, returns to userspace
don't need to take care of clearing the marker.

Furthermore, as I don't have the ability to test this on Book 3E or 32
bits, limit the change to Book 3S and 64 bits.

Fixes: df78d3f6 ("powerpc/livepatch: Implement reliable stack tracing for the consistency model")
Reported-by: Joe Lawrence <joe.lawrence@redhat.com>
Signed-off-by: Nicolai Stange <nstange@suse.de>
Signed-off-by: Joe Lawrence <joe.lawrence@redhat.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

Add mem-loads/mem-stores events to sysfs.
The event is formed based on raw event encoding.
Primary PMU event used here is PM_MRK_INST_CMPL
along with MMCRA[SM] modes and Thresholding bit
Signed-off-by: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

In htab_convert_pte_flags(), _PAGE_CACHE_CTL is used to check for the
_PAGE_SAO flag:

  else if ((pteflags & _PAGE_CACHE_CTL) == _PAGE_SAO)
          rflags |= (HPTE_R_W | HPTE_R_I | HPTE_R_M);

But, it isn't defined to include that flag:

  #define _PAGE_CACHE_CTL (_PAGE_NON_IDEMPOTENT | _PAGE_TOLERANT)

This happens to work, but only because of the flag values:

  #define _PAGE_SAO               0x00010 /* Strong access order */
  #define _PAGE_NON_IDEMPOTENT    0x00020 /* non idempotent memory */
  #define _PAGE_TOLERANT          0x00030 /* tolerant memory, cache inhibited */

To prevent any issues if these particulars ever change, add _PAGE_SAO to
the mask.
Suggested-by: Charles Johns <crjohns@us.ibm.com>
Signed-off-by: Reza Arbab <arbab@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

Remove linux/syscalls.h which is included more than once
Signed-off-by: Sabyasachi Gupta <sabyasachi.linux@gmail.com>
Acked-by: Souptick Joarder <jrdr.linux@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

Remove linux/printk.h which is included more than once.
Signed-off-by: Sabyasachi Gupta <sabyasachi.linux@gmail.com>
Acked-by: Souptick Joarder <jrdr.linux@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

Remove linux/rtc.h which is included more than once
Signed-off-by: Brajeswar Ghosh <brajeswar.linux@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

Within cxl module, iteration over array 'adapter->afu' may be racy
at few points as it might be simultaneously read during an EEH and its
contents being set to NULL while driver is being unloaded or unbound
from the adapter. This might result in a NULL pointer to 'struct afu'
being de-referenced during an EEH thereby causing a kernel oops.

This patch fixes this by making sure that all access to the array
'adapter->afu' is wrapped within the context of spin-lock
'adapter->afu_list_lock'.

Fixes: 9e8df8a2 ("cxl: EEH support")
Cc: stable@vger.kernel.org # v4.3+
Acked-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Acked-by: Frederic Barrat <fbarrat@linux.ibm.com>
Acked-by: Christophe Lombard <clombard@linux.vnet.ibm.com>
Signed-off-by: Vaibhav Jain <vaibhav@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

Today's message is useless:

  [   42.253267] Kernel stack overflow in process (ptrval), r1=c65500b0

This patch fixes it:

  [   66.905235] Kernel stack overflow in process sh[356], r1=c65560b0

Fixes: ad67b74d ("printk: hash addresses printed with %p")
Cc: stable@vger.kernel.org # v4.15+
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
[mpe: Use task_pid_nr()]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

On pseries systems, performing a partition migration can result in
altering the nodes a CPU is assigned to on the destination system. For
exampl, pre-migration on the source system CPUs are in node 1 and 3,
post-migration on the destination system CPUs are in nodes 2 and 3.

Handling the node change for a CPU can cause corruption in the slab
cache if we hit a timing where a CPUs node is changed while cache_reap()
is invoked. The corruption occurs because the slab cache code appears
to rely on the CPU and slab cache pages being on the same node.

The current dynamic updating of a CPUs node done in arch/powerpc/mm/numa.c
does not prevent us from hitting this scenario.

Changing the device tree property update notification handler that
recognizes an affinity change for a CPU to do a full DLPAR remove and
add of the CPU instead of dynamically changing its node resolves this
issue.
Signed-off-by: Nathan Fontenot <nfont@linux.vnet.ibm.com>
Signed-off-by: Michael W. Bringmann <mwb@linux.vnet.ibm.com>
Tested-by: Michael W. Bringmann <mwb@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

WARN_ON() already contains an unlikely(), so it's not necessary to
wrap it into another.
Signed-off-by: Igor Stoppa <igor.stoppa@huawei.com>
Cc: Arseny Solokha <asolokha@kb.kras.ru>
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
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

GCC supports -mcpu=G4

This patch gives the opportunity to select ALTIVEC for this variant.
Signed-off-by: Mathieu Malaterre <malat@debian.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

On Power9 machines (64-bit Book3S), we can be running with either the
Hash table or Radix tree MMU enabled. So add some text to the __die()
output to tell us which is enabled, for the case where all you have is
the oops output and no other information.

Example output:

  kernel BUG at drivers/misc/lkdtm/bugs.c:63!
  Oops: Exception in kernel mode, sig: 5 [#1]
  LE PAGE_SIZE=64K MMU=Hash SMP NR_CPUS=2048 NUMA pSeries
  Modules linked in: kvm vmx_crypto binfmt_misc ip_tables x_tables
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Reviewed-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

The page size the kernel is built with is useful info when debugging a
crash, so add it to the output in __die().

Result looks like eg:

  kernel BUG at drivers/misc/lkdtm/bugs.c:63!
  Oops: Exception in kernel mode, sig: 5 [#1]
  LE PAGE_SIZE=64K SMP NR_CPUS=2048 NUMA pSeries
  Modules linked in: vmx_crypto kvm binfmt_misc ip_tables
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Reviewed-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

Using pr_cont() risks having our output interleaved with other output
from other CPUs. Instead print everything in a single printk() call.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Reviewed-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

A new self test that forces MSR[TS] to be set without calling any TM
instruction. This test also tries to cause a page fault at a signal
handler, exactly between MSR[TS] set and tm_recheckpoint(), forcing
thread->texasr to be rewritten with TEXASR[FS] = 0, which will cause a BUG
when tm_recheckpoint() is called.

This test is not deterministic, since it is hard to guarantee that the page
access will cause a page fault. In order to force more page faults at
signal context, the signal handler and the ucontext are being mapped into a
MADV_DONTNEED memory chunks.

Tests have shown that the bug could be exposed with few interactions in a
buggy kernel. This test is configured to loop 5000x, having a good chance
to hit the kernel issue in just one run.  This self test takes less than
two seconds to run.

This test uses set/getcontext because the kernel will recheckpoint
zeroed structures, causing the test to segfault, which is undesired because
the test needs to rerun, so, there is a signal handler for SIGSEGV which
will restart the test.

v2: Uses the MADV_DONTNEED memory advice
v3: Fix memcpy and 32-bits compilation
v4: Does not define unused macros
Signed-off-by: Breno Leitao <leitao@debian.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

The Wii has POWER and EJECT buttons, which are connected through
normalization logic to the GPIO controller (the length of an assertion
of these signals is always the same, regardless of how long the user
pressed the buttons).
Signed-off-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

The Hollywood GPIO controller is connected to the Hollywood PIC (&PIC1)
at IRQs 10 and 11; IRQ 10 for GPIO lines that are configured for access
by the PPC, 11 for GPIO lines that are configured for access by the
ARM926.
Signed-off-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

TCE_KILL_INVAL_ALL has moved long ago but the comment was forgotted so
finish the move and remove the comment.

Fixes: 0bbcdb43 "powerpc/powernv/npu: TCE Kill helpers cleanup"
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

This removes never used symbol - pnv_power9_force_smt4.

Note that we might still want to add stubs for:
	void pnv_power9_force_smt4_catch(void);
	void pnv_power9_force_smt4_release(void);

Fixes: 7672691a "powerpc/powernv: Provide a way to force a core into SMT4 mode"
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

This adds some stubs for hash only configs.
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

In the ld documentation under Builtin Functions:

  BLOCK(exp)

    This is a synonym for ALIGN, for compatibility with older linker scripts.

Clang's linker (lld) doesn't know about BLOCK so remove this use of
it.
Suggested-by: George Rimar <grimar@accesssoftek.com>
Signed-off-by: Joel Stanley <joel@jms.id.au>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

I wanted to test the virtex440-ml507 qemu machine and found that the
dtb for it was not built.

All powerpc dtbs are only built when CONFIG_OF_ALL_DTBS is set which
depend on COMPILE_TEST.

This patch enables building of the virtex dtbs when
CONFIG_XILINX_VIRTEX440_GENERIC_BOARD is enabled.
Signed-off-by: Corentin Labbe <clabbe@baylibre.com>
[mpe: Put both targets on a single line]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

ipic_set_highest_priority(), ipic_enable_mcp() and ipic_disable_mcp()
are unused. This patch drops them.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

One of the more common cases of allocation size calculations is finding
the size of a structure that has a zero-sized array at the end, along
with memory for some number of elements for that array. For example:

struct foo {
    int stuff;
    void *entry[];
};

instance = kmalloc(sizeof(struct foo) + sizeof(void *) * count, GFP_KERNEL);

Instead of leaving these open-coded and prone to type mistakes, we can
now use the new struct_size() helper:

instance = kmalloc(struct_size(instance, entry, count), GFP_KERNEL);

This code was detected with the help of Coccinelle.
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

The header search path -I. in kernel Makefiles is very suspicious;
it allows the compiler to search for headers in the top of $(srctree),
where obviously no header file exists.

-Iinclude/math-emu seems unnecessary because all files include headers
in the form of #include <math-emu/...>.

I was able to build without these header search paths.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

The same path -Iarch/$(ARCH) is passed to KBUILD_CPPFLAGS,
KBUILD_AFLAGS, and KBUILD_CFLAGS.

As you see in scripts/Makefile.lib, KBUILD_CPPFLAGS is passed
to c_flags and a_flags as well.

Passing it to KBUILD_CPPFLAGS is enough.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

The header search path -I. in kernel Makefiles is very suspicious;
it allows the compiler to search for headers in the top of $(srctree),
where obviously no header file exists.

Commit 46f43c6e ("KVM: powerpc: convert marker probes to event
trace") first added these options, but they are completely useless.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

Use DEFINE_DEBUGFS_ATTRIBUTE rather than DEFINE_SIMPLE_ATTRIBUTE
for debugfs files.

Generated by: scripts/coccinelle/api/debugfs/debugfs_simple_attr.cocci
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

arch_early_irq_init() does nothing different than the weak
arch_early_irq_init() in kernel/softirq.c

Fixes: 089fb442 ("powerpc: Use ARCH_IRQ_INIT_FLAGS")
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

One of the more common cases of allocation size calculations is finding the
size of a structure that has a zero-sized array at the end, along with memory
for some number of elements for that array. For example:

struct foo {
    int stuff;
    void *entry[];
};

instance = kzalloc(sizeof(struct foo) + sizeof(void *) * count, GFP_KERNEL);

Instead of leaving these open-coded and prone to type mistakes, we can now
use the new struct_size() helper:

instance = kzalloc(struct_size(instance, entry, count), GFP_KERNEL);

This code was detected with the help of Coccinelle.
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

Signed-off-by: Matteo Croce <mcroce@redhat.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

Use a CONSOLE_LOGLEVEL_DEBUG macro for console_loglevel rather
than a naked number.
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

UNAME26 is a mechanism to report Linux's version as 2.6.x, for
compatibility with old/broken software.  Due to the way it is
implemented, it would have to be updated after 5.0, to keep the
resulting versions unique.  Linus Torvalds argued:

 "Do we actually need this?

  I'd rather let it bitrot, and just let it return random versions. It
  will just start again at 2.4.60, won't it?

  Anybody who uses UNAME26 for a 5.x kernel might as well think it's
  still 4.x. The user space is so old that it can't possibly care about
  differences between 4.x and 5.x, can it?

  The only thing that matters is that it shows "2.4.<largeenough>",
  which it will do regardless"
Signed-off-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull ARM SoC fixes from Olof Johansson:
 "A bigger batch than I anticipated this week, for two reasons:

   - Some fallout on Davinci from board file -> DTB conversion, that
     also includes a few longer-standing fixes (i.e. not recent
     regressions).

   - drivers/reset material that has been in linux-next for a while, but
     didn't get sent to us until now for a variety of reasons
     (maintainer out sick, holidays, etc). There's a functional
     dependency in there such that one platform (Altera's SoCFPGA) won't
     boot without one of the patches; instead of reverting the patch
     that got merged, I looked at this set and decided it was small
     enough that I'll pick it up anyway. If you disagree I can revisit
     with a smaller set.

  That being said, there's also a handful of the usual stuff:

   - Fix for a crash on Armada 7K/8K when the kernel touches
     PSCI-reserved memory

   - Fix for PCIe reset on Macchiatobin (Armada 8K development board,
     what this email is sent from in fact :)

   - Enable a few new-merged modules for Amlogic in arm64 defconfig

   - Error path fixes on Integrator

   - Build fix for Renesas and Qualcomm

   - Initialization fix for Renesas RZ/G2E

  .. plus a few more fixlets"

* tag 'armsoc-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: (28 commits)
  ARM: integrator: impd1: use struct_size() in devm_kzalloc()
  qcom-scm: Include <linux/err.h> header
  gpio: pl061: handle failed allocations
  ARM: dts: kirkwood: Fix polarity of GPIO fan lines
  arm64: dts: marvell: mcbin: fix PCIe reset signal
  arm64: dts: marvell: armada-ap806: reserve PSCI area
  ARM: dts: da850-lcdk: Correct the sound card name
  ARM: dts: da850-lcdk: Correct the audio codec regulators
  ARM: dts: da850-evm: Correct the sound card name
  ARM: dts: da850-evm: Correct the audio codec regulators
  ARM: davinci: omapl138-hawk: fix label names in GPIO lookup entries
  ARM: davinci: dm644x-evm: fix label names in GPIO lookup entries
  ARM: davinci: dm355-evm: fix label names in GPIO lookup entries
  ARM: davinci: da850-evm: fix label names in GPIO lookup entries
  ARM: davinci: da830-evm: fix label names in GPIO lookup entries
  arm64: defconfig: enable modules for amlogic s400 sound card
  reset: uniphier-glue: Add AHCI reset control support in glue layer
  dt-bindings: reset: uniphier: Add AHCI core reset description
  reset: uniphier-usb3: Rename to reset-uniphier-glue
  dt-bindings: reset: uniphier: Replace the expression of USB3 with generic peripherals
  ...

Pull btrfs fixes from David Sterba:

 - two regression fixes in clone/dedupe ioctls, the generic check
   callback needs to lock extents properly and wait for io to avoid
   problems with writeback and relocation

 - fix deadlock when using free space tree due to block group creation

 - a recently added check refuses a valid fileystem with seeding device,
   make that work again with a quickfix, proper solution needs more
   intrusive changes

* tag 'for-5.0-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  btrfs: Use real device structure to verify dev extent
  Btrfs: fix deadlock when using free space tree due to block group creation
  Btrfs: fix race between reflink/dedupe and relocation
  Btrfs: fix race between cloning range ending at eof and writeback

Pull driver core fixes from Greg KH:
 "Here is one small sysfs change, and a documentation update for 5.0-rc2

  The sysfs change moves from using BUG_ON to WARN_ON, as discussed in
  an email thread on lkml while trying to track down another driver bug.
  sysfs should not be crashing and preventing people from seeing where
  they went wrong. Now it properly recovers and warns the developer.

  The documentation update removes the use of BUS_ATTR() as the kernel
  is moving away from this to use the specific BUS_ATTR_RW() and friends
  instead. There are pending patches in all of the different subsystems
  to remove the last users of this macro, but for now, don't advertise
  it should be used anymore to keep new ones from being introduced.

  Both have been in linux-next with no reported issues"

* tag 'driver-core-5.0-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
  Documentation: driver core: remove use of BUS_ATTR
  sysfs: convert BUG_ON to WARN_ON