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: NSanthosh <santhog4@linux.vnet.ibm.com>
Signed-off-by: NAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Acked-by: NBalbir Singh <bsingharora@gmail.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

The HMI (Hypervisor Maintenance Interrupt) is defined by the
architecture to be higher priority than other maskable interrupts, so
replay it first, as a best-effort to replay according to hardware
priorities.
Signed-off-by: NNicholas Piggin <npiggin@gmail.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

In our linker script we open code the list of text sections, because we
need to include the __ftr_alt sections, which are arch-specific.

This means we can't use TEXT_TEXT as defined in vmlinux.lds.h, and so we
don't have the MEM_KEEP() logic for memory hotplug sections.

If we build the kernel with the gold linker, and with CONFIG_MEMORY_HOTPLUG=y,
we see that functions marked __meminit can end up outside of the
_stext/_etext range, and also outside of _sinittext/_einittext, eg:

    c000000000000000 T _stext
    c0000000009e0000 A _etext
    c0000000009e3f18 T hash__vmemmap_create_mapping
    c000000000ca0000 T _sinittext
    c000000000d00844 T _einittext

This causes them to not be recognised as text by is_kernel_text(), and
prevents them being patched by jump_label (and presumably ftrace/kprobes
etc.).

Fix it by adding MEM_KEEP() directives, mirroring what TEXT_TEXT does.

This isn't a problem when CONFIG_MEMORY_HOTPLUG=n, because we use the
standard INIT_TEXT_SECTION() and EXIT_TEXT macros from vmlinux.lds.h.
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Tested-by: NAnton Blanchard <anton@samba.org>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

Currently the _GLOBAL() macro unilaterally sets the assembler section to
".text" at the start of the macro. This is rude as the caller may be
using a different section.

So let the caller decide which section to emit the code into. On big
endian we do need to switch to the ".opd" section to emit the OPD, but
do that with pushsection/popsection, thereby leaving the original
section intact.

I verified that the order of all entries in System.map is unchanged
after this patch. The actual addresses shift around slightly so you
can't just diff the System.map.
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Reviewed-by: NNicholas Piggin <npiggin@gmail.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

Rather than forcing the whole function into the ".kprobes.text" section,
just add the symbol's address to the kprobe blacklist.

This also lets us drop the three versions of the_KPROBE macro, in
exchange for just one version of _ASM_NOKPROBE_SYMBOL - which is a good
cleanup.
Signed-off-by: NNicholas Piggin <npiggin@gmail.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

Currently we mark the C implementations of some exception handlers as
__kprobes. This has the effect of putting them in the ".kprobes.text"
section, which separates them from the rest of the text.

Instead we can use the blacklist macros to add the symbols to a
blacklist which kprobes will check. This allows the linker to move
exception handler functions close to callers and avoids trampolines in
larger kernels.
Signed-off-by: NNicholas Piggin <npiggin@gmail.com>
[mpe: Reword change log a bit]
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

Normally, when MSR[VSX/VR/SPE] bits == 1, the used_vsr/used_vr/used_spe
bit have already been set. However when loading a signal frame from user
space we need to explicitly set used_vsr/used_vr/used_spe to make them
consistent with the MSR bits from the signal frame.

For example, CRIU application, who utilizes sigreturn to restore
checkpointed process, will lead to the case where MSR[VSX] bit is active
in signal frame, but used_vsr bit is not set in the kernel. (the same
applies to VR/SPE).

This patch fixes this by always setting used_* bit when MSR related bits
are active in signal frame and we are doing sigreturn.

Based on a proposal by Benh.
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: NSimon Guo <wei.guo.simon@gmail.com>
[mpe: Massage change log]
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

The ckpt_regs usage in gpr32_set_common/gpr32_get_common() will lead to
following cppcheck error at ifndef CONFIG_PPC_TRANSACTIONAL_MEM case:

[arch/powerpc/kernel/ptrace.c:2062]:
(error) Uninitialized variable: ckpt_regs
[arch/powerpc/kernel/ptrace.c:2130]:
(error) Uninitialized variable: ckpt_regs

The problem is due to gpr32_set_common() used ckpt_regs variable which
only makes sense at #ifdef CONFIG_PPC_TRANSACTIONAL_MEM.

This patch fix this issue by passing in "regs" parameter instead.
Reported-by: NDaniel Axtens <dja@axtens.net>
Signed-off-by: NSimon Guo <wei.guo.simon@gmail.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

The message is missing a \n, add it. Switch to pr_warn(), it's shorter
and less ugly.
Signed-off-by: NColin Ian King <colin.king@canonical.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

Power9 DD1 requires to update the hid0 register when switching from
hash to radix.
Signed-off-by: NAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Acked-by: NMichael Neuling <mikey@neuling.org>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

POWER9 DD1 requires pte to be marked invalid (V=0) before updating
it with the new value. This makes this distinction for the different
revisions.
Signed-off-by: NAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Acked-by: NMichael Neuling <mikey@neuling.org>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

POWER9 DD1 uses RTS - 28 for the RTS value but other revisions use
RTS - 31.  This makes this distinction for the different revisions
Signed-off-by: NAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Acked-by: NMichael Neuling <mikey@neuling.org>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

Signed-off-by: NAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Acked-by: NMichael Neuling <mikey@neuling.org>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

The of_node for the SB600 (io-bridge) has its device_type set to
'io-bridge' Set it to 'isa' so that it can be found by
isa_bridge_find_early() instead of using patches in the kernel.
Signed-off-by: NDarren Stevens <darren@stevens-zone.net>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

The device tree on the Nemo passes all of the i8259 interrupts with
numbers between 212 and 222, and points their interrupt-parent property
to the pasemi-opic, requiring custom patches to the kernel. Fix the
values so that they can be controlled by the generic ppc i8259 code.
Signed-off-by: NDarren Stevens <darren@stevens-zone.net>
[mpe: Rework deeply nested if and boundary checks]
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

Add config option for the Nemo motherboard used in the Amigaone X1000.
This is a custom PASemi board with an AMD SB600 southbridge, and needs
some patches to it device tree. This option will be used to build these
into the kernel
Signed-off-by: NDarren Stevens <darren@stevens-zone.net>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

Trivial fix to spelling mistake in dev_warn message and remove
extraneous trailing whitespace at end of the message.
Signed-off-by: NColin Ian King <colin.king@canonical.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

Use the standard Kbuild trick of foo-y to make the construction of
UTC_MACHINE less verbose.
Signed-off-by: NMichael 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: NMichael Ellerman <mpe@ellerman.id.au>

Some of the rules in the boot Makefile use @ to hide the command, this
means "make V=1" doesn't show them, which is confusing.

So use the Kbuild standard $(Q) which means KBUILD_VERBOSE=1 or V=1 will
work as expected.
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

We can just use the standard .S -> .o rule, cmd_as_o_S.
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

In fact it makes no sense at all to have this defined on little endian
builds. Since we disabled the 32-bit VDSO on little endian, we don't
build any 32-bit code when building a little endian kernel.
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

The LOAD_HANDLER macro requires that you have previously loaded "reg"
with PACAKBASE. Although that gives callers flexibility to get PACAKBASE
in some interesting way, none of the callers actually do that. So fold
the load of PACAKBASE into the macro, making it simpler for callers to
use correctly.
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Reviewed-by: NNick Piggin <npiggin@gmail.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

The comment for LOAD_HANDLER() was wrong. The part about kdump has not
been true since 1f6a93e4 ("powerpc: Make it possible to move the
interrupt handlers away from the kernel").

Describe how it currently works, and combine the two separate comments
into one.
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Reviewed-by: NNick Piggin <npiggin@gmail.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

Currently, if userspace or the kernel accesses a completely bogus address,
for example with any of bits 46-59 set, we first take an SLB miss interrupt,
install a corresponding SLB entry with VSID 0, retry the instruction, then
take a DSI/ISI interrupt because there is no HPT entry mapping the address.
However, by the time of the second interrupt, the Come-From Address Register
(CFAR) has been overwritten by the rfid instruction at the end of the SLB
miss interrupt handler.  Since bogus accesses can often be caused by a
function return after the stack has been overwritten, the CFAR value would
be very useful as it could indicate which function it was whose return had
led to the bogus address.

This patch adds code to create a full exception frame in the SLB miss handler
in the case of a bogus address, rather than inserting an SLB entry with a
zero VSID field.  Then we call a new slb_miss_bad_addr() function in C code,
which delivers a signal for a user access or creates an oops for a kernel
access.  In the latter case the oops message will show the CFAR value at the
time of the access.

In the case of the radix MMU, a segment miss interrupt indicates an access
outside the ranges mapped by the page tables.  Previously this was handled
by the code for an unrecoverable SLB miss (one with MSR[RI] = 0), which is
not really correct.  With this patch, we now handle these interrupts with
slb_miss_bad_addr(), which is much more consistent.
Signed-off-by: NPaul Mackerras <paulus@ozlabs.org>
Reviewed-by: NAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

In commit 31cdd0c3 ("powerpc/xmon: Fix SPR read/write commands and
add command to dump SPRs") I added two uses of the "ld" instruction in
spr_access.S. "ld" is a 64-bit instruction, so shouldn't be used on
32-bit CPUs.

Replace it with PPC_LL which is a macro that gives us either "ld" or
"lwz" depending on whether we're 64 or 32-bit.

Fixes: 31cdd0c3 ("powerpc/xmon: Fix SPR read/write commands and add command to dump SPRs")
Cc: stable@vger.kernel.org # v4.7+
Reported-by: NJohn Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

Another set of things that are only called from assembler and so need
prototypes to keep sparse happy.
Signed-off-by: NDaniel Axtens <dja@axtens.net>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

Firmware Assisted Dump is a facility to dump kernel core with assistance
from firmware. As part of this process the kernel ELF ABI version is
stored in the core file.

Currently fadump.h defines this to 0 if it is not already defined. This
clashes with a define in elf.h which sets it based on the current task -
not based on the kernel's ELF ABI version.

Use the compiler-provided #define _CALL_ELF which tells us the ELF ABI
version of the kernel to set e_flags, this matches what binutils does.

Remove the definition in fadump.h, which becomes unused.
Signed-off-by: NDaniel Axtens <dja@axtens.net>
Reviewed-by: NMahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

Squash a bunch of sparse warnings by making things static.
Reviewed-by: NAndrew Donnellan <andrew.donnellan@au1.ibm.com>
Signed-off-by: NDaniel Axtens <dja@axtens.net>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

Sparse checking revealed that it is no longer used. The last usage was
removed in commit 2e194583 ("[POWERPC] Cell interrupt rework") in
2006.
Signed-off-by: NDaniel Axtens <dja@axtens.net>
Reviewed-by: NAndrew Donnellan <andrew.donnellan@au1.ibm.com>
Acked-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

AMD F12h machines have an erratum which can cause DIV/IDIV to behave
unpredictably. The workaround is to set MSRC001_1029[31] but sometimes
there is no BIOS update containing that workaround so let's do it
ourselves unconditionally. It is simple enough.

[ Borislav: Wrote commit message. ]
Signed-off-by: NEmanuel Czirai <icanrealizeum@gmail.com>
Signed-off-by: NBorislav Petkov <bp@suse.de>
Cc: Yaowu Xu <yaowu@google.com>
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/20160902053550.18097-1-bp@alien8.deSigned-off-by: NThomas Gleixner <tglx@linutronix.de>

Łukasz Daniluk reported that on a RHEL kernel that his machine would lock up
after enabling function tracer. I asked him to bisect the functions within
available_filter_functions, which he did and it came down to three:

  _paravirt_nop(), _paravirt_ident_32() and _paravirt_ident_64()

It was found that this is only an issue when noreplace-paravirt is added
to the kernel command line.

This means that those functions are most likely called within critical
sections of the funtion tracer, and must not be traced.

In newer kenels _paravirt_nop() is defined within gcc asm(), and is no
longer an issue.  But both _paravirt_ident_{32,64}() causes the
following splat when they are traced:

 mm/pgtable-generic.c:33: bad pmd ffff8800d2435150(0000000001d00054)
 mm/pgtable-generic.c:33: bad pmd ffff8800d3624190(0000000001d00070)
 mm/pgtable-generic.c:33: bad pmd ffff8800d36a5110(0000000001d00054)
 mm/pgtable-generic.c:33: bad pmd ffff880118eb1450(0000000001d00054)
 NMI watchdog: BUG: soft lockup - CPU#2 stuck for 22s! [systemd-journal:469]
 Modules linked in: e1000e
 CPU: 2 PID: 469 Comm: systemd-journal Not tainted 4.6.0-rc4-test+ #513
 Hardware name: Hewlett-Packard HP Compaq Pro 6300 SFF/339A, BIOS K01 v02.05 05/07/2012
 task: ffff880118f740c0 ti: ffff8800d4aec000 task.ti: ffff8800d4aec000
 RIP: 0010:[<ffffffff81134148>]  [<ffffffff81134148>] queued_spin_lock_slowpath+0x118/0x1a0
 RSP: 0018:ffff8800d4aefb90  EFLAGS: 00000246
 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffff88011eb16d40
 RDX: ffffffff82485760 RSI: 000000001f288820 RDI: ffffea0000008030
 RBP: ffff8800d4aefb90 R08: 00000000000c0000 R09: 0000000000000000
 R10: ffffffff821c8e0e R11: 0000000000000000 R12: ffff880000200fb8
 R13: 00007f7a4e3f7000 R14: ffffea000303f600 R15: ffff8800d4b562e0
 FS:  00007f7a4e3d7840(0000) GS:ffff88011eb00000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 00007f7a4e3f7000 CR3: 00000000d3e71000 CR4: 00000000001406e0
 Call Trace:
   _raw_spin_lock+0x27/0x30
   handle_pte_fault+0x13db/0x16b0
   handle_mm_fault+0x312/0x670
   __do_page_fault+0x1b1/0x4e0
   do_page_fault+0x22/0x30
   page_fault+0x28/0x30
   __vfs_read+0x28/0xe0
   vfs_read+0x86/0x130
   SyS_read+0x46/0xa0
   entry_SYSCALL_64_fastpath+0x1e/0xa8
 Code: 12 48 c1 ea 0c 83 e8 01 83 e2 30 48 98 48 81 c2 40 6d 01 00 48 03 14 c5 80 6a 5d 82 48 89 0a 8b 41 08 85 c0 75 09 f3 90 8b 41 08 <85> c0 74 f7 4c 8b 09 4d 85 c9 74 08 41 0f 18 09 eb 02 f3 90 8b
Reported-by: NŁukasz Daniluk <lukasz.daniluk@intel.com>
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>
Cc: stable@vger.kernel.org
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Changes to make the resume from cpu_suspend() code behave more like
secondary boot caused debug exceptions to be unmasked early by
__cpu_setup(). We then go on to restore mdscr_el1 in cpu_do_resume(),
potentially taking break or watch points based on uninitialised registers.

Mask debug exceptions in cpu_do_resume(), which is specific to resume
from cpu_suspend(). Debug exceptions will be restored to their original
state by local_dbg_restore() in cpu_suspend(), which runs after
hw_breakpoint_restore() has re-initialised the other registers.
Reported-by: NLorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Fixes: cabe1c81 ("arm64: Change cpu_resume() to enable mmu early then access sleep_sp by va")
Cc: <stable@vger.kernel.org> # 4.7+
Signed-off-by: NJames Morse <james.morse@arm.com>
Acked-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>

Using "make tinyconfig" produces a couple of annoying warnings that show
up for build test machines all the time:

    .config:966:warning: override: NOHIGHMEM changes choice state
    .config:965:warning: override: SLOB changes choice state
    .config:963:warning: override: KERNEL_XZ changes choice state
    .config:962:warning: override: CC_OPTIMIZE_FOR_SIZE changes choice state
    .config:933:warning: override: SLOB changes choice state
    .config:930:warning: override: CC_OPTIMIZE_FOR_SIZE changes choice state
    .config:870:warning: override: SLOB changes choice state
    .config:868:warning: override: KERNEL_XZ changes choice state
    .config:867:warning: override: CC_OPTIMIZE_FOR_SIZE changes choice state

I've made a previous attempt at fixing them and we discussed a number of
alternatives.

I tried changing the Makefile to use "merge_config.sh -n
$(fragment-list)" but couldn't get that to work properly.

This is yet another approach, based on the observation that we do want
to see a warning for conflicting 'choice' options, and that we can
simply make them non-conflicting by listing all other options as
disabled.  This is a trivial patch that we can apply independent of
plans for other changes.

Link: http://lkml.kernel.org/r/20160829214952.1334674-2-arnd@arndb.de
Link: https://storage.kernelci.org/mainline/v4.7-rc6/x86-tinyconfig/build.log
https://patchwork.kernel.org/patch/9212749/Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Reviewed-by: NJosh Triplett <josh@joshtriplett.org>
Reviewed-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: NIngo Molnar <mingo@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

There are three usercopy warnings which are currently being silenced for
gcc 4.6 and newer:

1) "copy_from_user() buffer size is too small" compile warning/error

   This is a static warning which happens when object size and copy size
   are both const, and copy size > object size.  I didn't see any false
   positives for this one.  So the function warning attribute seems to
   be working fine here.

   Note this scenario is always a bug and so I think it should be
   changed to *always* be an error, regardless of
   CONFIG_DEBUG_STRICT_USER_COPY_CHECKS.

2) "copy_from_user() buffer size is not provably correct" compile warning

   This is another static warning which happens when I enable
   __compiletime_object_size() for new compilers (and
   CONFIG_DEBUG_STRICT_USER_COPY_CHECKS).  It happens when object size
   is const, but copy size is *not*.  In this case there's no way to
   compare the two at build time, so it gives the warning.  (Note the
   warning is a byproduct of the fact that gcc has no way of knowing
   whether the overflow function will be called, so the call isn't dead
   code and the warning attribute is activated.)

   So this warning seems to only indicate "this is an unusual pattern,
   maybe you should check it out" rather than "this is a bug".

   I get 102(!) of these warnings with allyesconfig and the
   __compiletime_object_size() gcc check removed.  I don't know if there
   are any real bugs hiding in there, but from looking at a small
   sample, I didn't see any.  According to Kees, it does sometimes find
   real bugs.  But the false positive rate seems high.

3) "Buffer overflow detected" runtime warning

   This is a runtime warning where object size is const, and copy size >
   object size.

All three warnings (both static and runtime) were completely disabled
for gcc 4.6 with the following commit:

  2fb0815c ("gcc4: disable __compiletime_object_size for GCC 4.6+")

That commit mistakenly assumed that the false positives were caused by a
gcc bug in __compiletime_object_size().  But in fact,
__compiletime_object_size() seems to be working fine.  The false
positives were instead triggered by #2 above.  (Though I don't have an
explanation for why the warnings supposedly only started showing up in
gcc 4.6.)

So remove warning #2 to get rid of all the false positives, and re-enable
warnings #1 and #3 by reverting the above commit.

Furthermore, since #1 is a real bug which is detected at compile time,
upgrade it to always be an error.

Having done all that, CONFIG_DEBUG_STRICT_USER_COPY_CHECKS is no longer
needed.
Signed-off-by: NJosh Poimboeuf <jpoimboe@redhat.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: "H . Peter Anvin" <hpa@zytor.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Byungchul Park <byungchul.park@lge.com>
Cc: Nilay Vaish <nilayvaish@gmail.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Commit b70661c7 ("net: smc91x: use run-time configuration on all ARM
machines") broke some ARM platforms through several mistakes.  Firstly,
the access size must correspond to the following rule:

(a) at least one of 16-bit or 8-bit access size must be supported
(b) 32-bit accesses are optional, and may be enabled in addition to
    the above.

Secondly, it provides no emulation of 16-bit accesses, instead blindly
making 16-bit accesses even when the platform specifies that only 8-bit
is supported.

Reorganise smc91x.h so we can make use of the existing 16-bit access
emulation already provided - if 16-bit accesses are supported, use
16-bit accesses directly, otherwise if 8-bit accesses are supported,
use the provided 16-bit access emulation.  If neither, BUG().  This
exactly reflects the driver behaviour prior to the commit being fixed.

Since the conversion incorrectly cut down the available access sizes on
several platforms, we also need to go through every platform and fix up
the overly-restrictive access size: Arnd assumed that if a platform can
perform 32-bit, 16-bit and 8-bit accesses, then only a 32-bit access
size needed to be specified - not so, all available access sizes must
be specified.

This likely fixes some performance regressions in doing this: if a
platform does not support 8-bit accesses, 8-bit accesses have been
emulated by performing a 16-bit read-modify-write access.

Tested on the Intel Assabet/Neponset platform, which supports only 8-bit
accesses, which was broken by the original commit.

Fixes: b70661c7 ("net: smc91x: use run-time configuration on all ARM machines")
Signed-off-by: NRussell King <rmk+kernel@armlinux.org.uk>
Tested-by: NRobert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Userspace can begin and suspend a transaction within the signal
handler which means they might enter sys_rt_sigreturn() with the
processor in suspended state.

sys_rt_sigreturn() wants to restore process context (which may have
been in a transaction before signal delivery). To do this it must
restore TM SPRS. To achieve this, any transaction initiated within the
signal frame must be discarded in order to be able to restore TM SPRs
as TM SPRs can only be manipulated non-transactionally..
>From the PowerPC ISA:
  TM Bad Thing Exception [Category: Transactional Memory]
   An attempt is made to execute a mtspr targeting a TM register in
   other than Non-transactional state.

Not doing so results in a TM Bad Thing:
[12045.221359] Kernel BUG at c000000000050a40 [verbose debug info unavailable]
[12045.221470] Unexpected TM Bad Thing exception at c000000000050a40 (msr 0x201033)
[12045.221540] Oops: Unrecoverable exception, sig: 6 [#1]
[12045.221586] SMP NR_CPUS=2048 NUMA PowerNV
[12045.221634] Modules linked in: xt_CHECKSUM iptable_mangle ipt_MASQUERADE
 nf_nat_masquerade_ipv4 iptable_nat nf_nat_ipv4 nf_nat nf_conntrack_ipv4 nf_defrag_ipv4
 xt_conntrack nf_conntrack ipt_REJECT nf_reject_ipv4 xt_tcpudp bridge stp llc ebtable_filter
 ebtables ip6table_filter ip6_tables iptable_filter ip_tables x_tables kvm_hv kvm
 uio_pdrv_genirq ipmi_powernv uio powernv_rng ipmi_msghandler autofs4 ses enclosure
 scsi_transport_sas bnx2x ipr mdio libcrc32c
[12045.222167] CPU: 68 PID: 6178 Comm: sigreturnpanic Not tainted 4.7.0 #34
[12045.222224] task: c0000000fce38600 ti: c0000000fceb4000 task.ti: c0000000fceb4000
[12045.222293] NIP: c000000000050a40 LR: c0000000000163bc CTR: 0000000000000000
[12045.222361] REGS: c0000000fceb7ac0 TRAP: 0700   Not tainted (4.7.0)
[12045.222418] MSR: 9000000300201033 <SF,HV,ME,IR,DR,RI,LE,TM[SE]> CR: 28444280  XER: 20000000
[12045.222625] CFAR: c0000000000163b8 SOFTE: 0 PACATMSCRATCH: 900000014280f033
GPR00: 01100000b8000001 c0000000fceb7d40 c00000000139c100 c0000000fce390d0
GPR04: 900000034280f033 0000000000000000 0000000000000000 0000000000000000
GPR08: 0000000000000000 b000000000001033 0000000000000001 0000000000000000
GPR12: 0000000000000000 c000000002926400 0000000000000000 0000000000000000
GPR16: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
GPR20: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
GPR24: 0000000000000000 00003ffff98cadd0 00003ffff98cb470 0000000000000000
GPR28: 900000034280f033 c0000000fceb7ea0 0000000000000001 c0000000fce390d0
[12045.223535] NIP [c000000000050a40] tm_restore_sprs+0xc/0x1c
[12045.223584] LR [c0000000000163bc] tm_recheckpoint+0x5c/0xa0
[12045.223630] Call Trace:
[12045.223655] [c0000000fceb7d80] [c000000000026e74] sys_rt_sigreturn+0x494/0x6c0
[12045.223738] [c0000000fceb7e30] [c0000000000092e0] system_call+0x38/0x108
[12045.223806] Instruction dump:
[12045.223841] 7c800164 4e800020 7c0022a6 f80304a8 7c0222a6 f80304b0 7c0122a6 f80304b8
[12045.223955] 4e800020 e80304a8 7c0023a6 e80304b0 <7c0223a6> e80304b8 7c0123a6 4e800020
[12045.224074] ---[ end trace cb8002ee240bae76 ]---

It isn't clear exactly if there is really a use case for userspace
returning with a suspended transaction, however, doing so doesn't (on
its own) constitute a bad frame. As such, this patch simply discards
the transactional state of the context calling the sigreturn and
continues.
Reported-by: NLaurent Dufour <ldufour@linux.vnet.ibm.com>
Signed-off-by: NCyril Bur <cyrilbur@gmail.com>
Tested-by: NLaurent Dufour <ldufour@linux.vnet.ibm.com>
Reviewed-by: NLaurent Dufour <ldufour@linux.vnet.ibm.com>
Acked-by: NSimon Guo <wei.guo.simon@gmail.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

In a situation, where Linux kernel gets notified about duplicate error log
from OPAL, it is been observed that kernel fails to remove sysfs entries
(/sys/firmware/opal/elog/0xXXXXXXXX) of such error logs. This is because,
we currently search the error log/dump kobject in the kset list via
'kset_find_obj()' routine. Which eventually increment the reference count
by one, once it founds the kobject.

So, unless we decrement the reference count by one after it found the kobject,
we would not be able to release the kobject properly later.

This patch adds the 'kobject_put()' which was missing earlier.
Signed-off-by: NMukesh Ojha <mukesh02@linux.vnet.ibm.com>
Cc: stable@vger.kernel.org
Reviewed-by: NVasant Hegde <hegdevasant@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

tabort_syscall runs with RI=1, so a nested recoverable machine
check will load the paca into r13 and overwrite what we loaded
it with, because exceptions returning to privileged mode do not
restore r13.

Fixes: b4b56f9e (powerpc/tm: Abort syscalls in active transactions)
Cc: stable@vger.kernel.org
Signed-off-by: NNick Piggin <npiggin@gmail.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Commit 97f2645f ("tree-wide: replace config_enabled() with
IS_ENABLED()") mostly killed config_enabled(), but some new users have
appeared for v4.8-rc1.  They are all used for a boolean option, so can
be replaced with IS_ENABLED() safely.

Link: http://lkml.kernel.org/r/1471970749-24867-1-git-send-email-yamada.masahiro@socionext.comSigned-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: NKees Cook <keescook@chromium.org>
Acked-by: NPeter Oberparleiter <oberpar@linux.vnet.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>