commit 1091670637be8bd34a39dd1ddcc0a10a7c88d4e2 upstream.

Use a more generic name for additional table sorting usecases,
such as the upcoming ORC table sorting feature. This tool is
not tied to exception table sorting anymore.

No functional changes intended.

[ mingo: Rewrote the changelog. ]
Signed-off-by: NShile Zhang <shile.zhang@linux.alibaba.com>
Acked-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Michal Marek <michal.lkml@markovi.net>
Cc: linux-kbuild@vger.kernel.org
Link: https://lkml.kernel.org/r/20191204004633.88660-6-shile.zhang@linux.alibaba.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
Acked-by: NCaspar Zhang <caspar@linux.alibaba.com>

commit 513f7f747e1cba81f28a436911fba0b485878ebd upstream.

Sven noticed that calling ioremap() and iounmap() multiple times leads
to a vmap memory leak:
	vmap allocation for size 4198400 failed:
	use vmalloc=<size> to increase size

It seems we missed calling vunmap() in iounmap().
Signed-off-by: NHelge Deller <deller@gmx.de>
Noticed-by: NSven Schnelle <svens@stackframe.org>
Cc: <stable@vger.kernel.org> # v3.16+
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 3fe6c873af2f2247544debdbe51ec29f690a2ccf upstream.

With debug info enabled (CONFIG_DEBUG_INFO=y) the resulting vmlinux may get
that huge that we need to increase the start addresss for the decompression
text section otherwise one will face a linker error.
Reported-by: NSven Schnelle <svens@stackframe.org>
Tested-by: NSven Schnelle <svens@stackframe.org>
Cc: stable@vger.kernel.org # v4.14+
Signed-off-by: NHelge Deller <deller@gmx.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 10835c854685393a921b68f529bf740fa7c9984d upstream.

On parisc the privilege level of a process is stored in the lowest two bits of
the instruction pointers (IAOQ0 and IAOQ1). On Linux we use privilege level 0
for the kernel and privilege level 3 for user-space. So userspace should not be
allowed to modify IAOQ0 or IAOQ1 of a ptraced process to change it's privilege
level to e.g. 0 to try to gain kernel privileges.

This patch prevents such modifications by always setting the two lowest bits to
one (which relates to privilege level 3 for user-space) if IAOQ0 or IAOQ1 are
modified via ptrace calls in the native and compat ptrace paths.

Link: https://bugs.gentoo.org/481768Reported-by: NJeroen Roovers <jer@gentoo.org>
Cc: <stable@vger.kernel.org>
Tested-by: NRolf Eike Beer <eike-kernel@sf-tec.de>
Signed-off-by: NHelge Deller <deller@gmx.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 34c32fc603311a72cb558e5e337555434f64c27b upstream.

On parisc the privilege level of a process is stored in the lowest two bits of
the instruction pointers (IAOQ0 and IAOQ1). On Linux we use privilege level 0
for the kernel and privilege level 3 for user-space. So userspace should not be
allowed to modify IAOQ0 or IAOQ1 of a ptraced process to change it's privilege
level to e.g. 0 to try to gain kernel privileges.

This patch prevents such modifications in the regset support functions by
always setting the two lowest bits to one (which relates to privilege level 3
for user-space) if IAOQ0 or IAOQ1 are modified via ptrace regset calls.

Link: https://bugs.gentoo.org/481768
Cc: <stable@vger.kernel.org> # v4.7+
Tested-by: NRolf Eike Beer <eike-kernel@sf-tec.de>
Signed-off-by: NHelge Deller <deller@gmx.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

[ Upstream commit 6b98d9134e14f5ef4bcf64b27eedf484ed19a1ec ]

Avoid such compiler warnings:
arch/parisc/math-emu/cnv_float.h:71:27: warning: ‘<<’ in boolean context, did you mean ‘<’ ? [-Wint-in-bool-context]
     ((Dintp1(dint_valueA) << 33 - SGL_EXP_LENGTH) || Dintp2(dint_valueB))
arch/parisc/math-emu/fcnvxf.c:257:6: note: in expansion of macro ‘Dint_isinexact_to_sgl’
  if (Dint_isinexact_to_sgl(srcp1,srcp2)) {
Signed-off-by: NHelge Deller <deller@gmx.de>
Signed-off-by: NSasha Levin <sashal@kernel.org>

commit 1829dda0e87f4462782ca81be474c7890efe31ce upstream.

LEVEL is a very common word, and now after many years it suddenly
clashed with another LEVEL define in the DRBD code.
Rename it to PA_ASM_LEVEL instead.
Reported-by: Nkbuild test robot <lkp@intel.com>
Signed-off-by: NHelge Deller <deller@gmx.de>
Cc: <stable@vger.kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit bdca5d64ee92abeacd6dada0bc6f6f8e6350dd67 upstream.

The LEVEL define clashed with the DRBD code.
Reported-by: Nkbuild test robot <lkp@intel.com>
Signed-off-by: NHelge Deller <deller@gmx.de>
Cc: <stable@vger.kernel.org> # v4.14+
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 3e1120f4b57bc12437048494ab56648edaa5b57d upstream.
Signed-off-by: NHelge Deller <deller@gmx.de>
CC: stable@vger.kernel.org # v4.9+
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit f324fa58327791b2696628b31480e7e21c745706 upstream.

When setting the instruction pointer on PA-RISC we also need
to set the back of the instruction queue to the new offset, otherwise
we will execute on instruction from the new location, and jumping
back to the old location stored in iaoq_b.
Signed-off-by: NSven Schnelle <svens@stackframe.org>
Signed-off-by: NHelge Deller <deller@gmx.de>
Fixes: 75ebedf1 ("parisc: Add HAVE_REGS_AND_STACK_ACCESS_API feature")
Cc: stable@vger.kernel.org # 4.19+
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 45efd871bf0a47648f119d1b41467f70484de5bc upstream.

While working on kretprobes for PA-RISC I was wondering while the
kprobes sanity test always fails on kretprobes. This is caused by
returning gpr20 instead of gpr28.
Signed-off-by: NSven Schnelle <svens@stackframe.org>
Signed-off-by: NHelge Deller <deller@gmx.de>
Cc: stable@vger.kernel.org # 4.14+
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit d006e95b5561f708d0385e9677ffe2c46f2ae345 upstream.

While adding LASI support to QEMU, I noticed that the QEMU detection in
the kernel happens much too late. For example, when a LASI chip is found
by the kernel, it registers the LASI LED driver as well.  But when we
run on QEMU it makes sense to avoid spending unnecessary CPU cycles, so
we need to access the running_on_QEMU flag earlier than before.

This patch now makes the QEMU detection the fist task of the Linux
kernel by moving it to where the kernel enters the C-coding.

Fixes: 310d8278 ("parisc: qemu idle sleep support")
Signed-off-by: NHelge Deller <deller@gmx.de>
Cc: stable@vger.kernel.org # v4.14+
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit b7dc5a071ddf69c0350396b203cba32fe5bab510 upstream.

Commit 910cd32e ("parisc: Fix and enable seccomp filter support")
introduced a regression in ptrace-based syscall tampering: when tracer
changes syscall number to -1, the kernel fails to initialize %r28 with
-ENOSYS and subsequently fails to return the error code of the failed
syscall to userspace.

This erroneous behaviour could be observed with a simple strace syscall
fault injection command which is expected to print something like this:

$ strace -a0 -ewrite -einject=write:error=enospc echo hello
write(1, "hello\n", 6) = -1 ENOSPC (No space left on device) (INJECTED)
write(2, "echo: ", 6) = -1 ENOSPC (No space left on device) (INJECTED)
write(2, "write error", 11) = -1 ENOSPC (No space left on device) (INJECTED)
write(2, "\n", 1) = -1 ENOSPC (No space left on device) (INJECTED)
+++ exited with 1 +++

After commit 910cd32e it loops printing
something like this instead:

write(1, "hello\n", 6../strace: Failed to tamper with process 12345: unexpectedly got no error (return value 0, error 0)
) = 0 (INJECTED)

This bug was found by strace test suite.

Fixes: 910cd32e ("parisc: Fix and enable seccomp filter support")
Cc: stable@vger.kernel.org # v4.5+
Signed-off-by: NDmitry V. Levin <ldv@altlinux.org>
Tested-by: NHelge Deller <deller@gmx.de>
Signed-off-by: NHelge Deller <deller@gmx.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

[ Upstream commit a8874e7e8a8896f2b6c641f4b8e2473eafd35204 ]

Change the currently empty defines for __PAGETABLE_PMD_FOLDED,
__PAGETABLE_PUD_FOLDED and __PAGETABLE_P4D_FOLDED to return 1.
This makes it possible to use __is_defined() to test if the
preprocessor define exists.
Acked-by: NKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: NSasha Levin <sashal@kernel.org>

commit 1e8249b8 upstream.

Frank Schreiner reported, that since kernel 4.18 he faces sysfs-warnings
when loading modules on a 32-bit kernel. Here is one such example:

 sysfs: cannot create duplicate filename '/module/nfs/sections/.text'
 CPU: 0 PID: 98 Comm: modprobe Not tainted 4.18.0-2-parisc #1 Debian 4.18.10-2
 Backtrace:
  [<1017ce2c>] show_stack+0x3c/0x50
  [<107a7210>] dump_stack+0x28/0x38
  [<103f900c>] sysfs_warn_dup+0x88/0xac
  [<103f8b1c>] sysfs_add_file_mode_ns+0x164/0x1d0
  [<103f9e70>] internal_create_group+0x11c/0x304
  [<103fa0a0>] sysfs_create_group+0x48/0x60
  [<1022abe8>] load_module.constprop.35+0x1f9c/0x23b8
  [<1022b278>] sys_finit_module+0xd0/0x11c
  [<101831dc>] syscall_exit+0x0/0x14

This warning gets triggered by the fact, that due to commit 24b6c225
("parisc: Build kernel without -ffunction-sections") we now get multiple .text
sections in the kernel modules for which sysfs_create_group() can't create
multiple virtual files.

This patch works around the problem by re-enabling the -ffunction-sections
compiler option for modules, while keeping it disabled for the non-module
kernel code.
Reported-by: NFrank Scheiner <frank.scheiner@web.de>
Fixes: 24b6c225 ("parisc: Build kernel without -ffunction-sections")
Cc: <stable@vger.kernel.org> # v4.18+
Signed-off-by: NHelge Deller <deller@gmx.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit a87532c78d291265efadc4b20a8c7a70cd59ea29 upstream.

The function_graph_enter() function does the work of calling the function
graph hook function and the management of the shadow stack, simplifying the
work done in the architecture dependent prepare_ftrace_return().

Have parisc use the new code, and remove the shadow stack management as well as
having to set up the trace structure.

This is needed to prepare for a fix of a design bug on how the curr_ret_stack
is used.

Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
Cc: Helge Deller <deller@gmx.de>
Cc: linux-parisc@vger.kernel.org
Cc: stable@kernel.org
Fixes: 03274a3f ("tracing/fgraph: Adjust fgraph depth before calling trace return callback")
Reviewed-by: NMasami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: NSteven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 99a3ae51d557d8e38a7aece65678a31f9db215ee upstream.

In the C-code we need to put the physical address of the hpmc handler in
the interrupt vector table (IVA) in order to get HPMCs working.  Since
on parisc64 function pointers are indirect (in fact they are function
descriptors) we instead export the address as variable and not as
function.

This reverts a small part of commit f39cce65 ("parisc: Add
cfi_startproc and cfi_endproc to assembly code").
Signed-off-by: NHelge Deller <deller@gmx.de>
Cc: <stable@vger.kernel.org>    [4.9+]
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 3c229b3f2dd8133f61bb81d3cb018be92f4bba39 upstream.

Fix a long-existing small nasty bug in the map_pages() implementation which
leads to overwriting already written pte entries with zero, *if* map_pages() is
called a second time with an end address which isn't aligned on a pmd boundry.
This happens for example if we want to remap only the text segment read/write
in order to run alternative patching on the code. Exiting the loop when we
reach the end address fixes this.

Cc: stable@vger.kernel.org
Signed-off-by: NHelge Deller <deller@gmx.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 1138b6718ff74d2a934459643e3754423d23b5e2 upstream.

Helge noticed that the address of the os_hpmc handler was not being
correctly calculated in the hpmc macro.  As a result, PDCE_CHECK would
fail to call os_hpmc:

<Cpu2> e800009802e00000  0000000000000000  CC_ERR_CHECK_HPMC
<Cpu2> 37000f7302e00000  8040004000000000  CC_ERR_CPU_CHECK_SUMMARY
<Cpu2> f600105e02e00000  fffffff0f0c00000  CC_MC_HPMC_MONARCH_SELECTED
<Cpu2> 140003b202e00000  000000000000000b  CC_ERR_HPMC_STATE_ENTRY
<Cpu2> 5600100b02e00000  00000000000001a0  CC_MC_OS_HPMC_LEN_ERR
<Cpu2> 5600106402e00000  fffffff0f0438e70  CC_MC_BR_TO_OS_HPMC_FAILED
<Cpu2> e800009802e00000  0000000000000000  CC_ERR_CHECK_HPMC
<Cpu2> 37000f7302e00000  8040004000000000  CC_ERR_CPU_CHECK_SUMMARY
<Cpu2> 4000109f02e00000  0000000000000000  CC_MC_HPMC_INITIATED
<Cpu2> 4000101902e00000  0000000000000000  CC_MC_MULTIPLE_HPMCS
<Cpu2> 030010d502e00000  0000000000000000  CC_CPU_STOP

The address problem can be seen by dumping the fault vector:

0000000040159000 <fault_vector_20>:
    40159000:   63 6f 77 73     stb r15,-2447(dp)
    40159004:   20 63 61 6e     ldil L%b747000,r3
    40159008:   20 66 6c 79     ldil L%-1c3b3000,r3
        ...
    40159020:   08 00 02 40     nop
    40159024:   20 6e 60 02     ldil L%15d000,r3
    40159028:   34 63 00 00     ldo 0(r3),r3
    4015902c:   e8 60 c0 02     bv,n r0(r3)
    40159030:   08 00 02 40     nop
    40159034:   00 00 00 00     break 0,0
    40159038:   c0 00 70 00     bb,*< r0,sar,40159840 <fault_vector_20+0x840>
    4015903c:   00 00 00 00     break 0,0

Location 40159038 should contain the physical address of os_hpmc:

000000004015d000 <os_hpmc>:
    4015d000:   08 1a 02 43     copy r26,r3
    4015d004:   01 c0 08 a4     mfctl iva,r4
    4015d008:   48 85 00 68     ldw 34(r4),r5

This patch moves the address setup into initialize_ivt to resolve the
above problem.  I tested the change by dumping the HPMC entry after setup:

0000000040209020:  8000240
0000000040209024: 206a2004
0000000040209028: 34630ac0
000000004020902c: e860c002
0000000040209030:  8000240
0000000040209034: 1bdddce6
0000000040209038:   15d000
000000004020903c:      1a0
Signed-off-by: NJohn David Anglin <dave.anglin@bell.net>
Cc: <stable@vger.kernel.org>
Signed-off-by: NHelge Deller <deller@gmx.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

As noticed by Dave Anglin, the last commit introduced a small bug where
the potentially uninitialized r struct is used instead of the regs
pointer as input for unwind_frame_init(). Fix it.
Signed-off-by: NHelge Deller <deller@gmx.de>
Reported-by: NJohn David Anglin <dave.anglin@bell.net>

Signed-off-by: NHelge Deller <deller@gmx.de>

Commit c8921d72 ("parisc: Fix and improve kernel stack unwinding")
broke booting of 64-bit kernels. On 64-bit kernels function pointers are
actually function descriptors which require dereferencing. In this patch
we instead declare functions in assembly code which are referenced from
C-code as external data pointers with the ENTRY() macro and thus can use
a simple external reference to the functions.
Signed-off-by: NHelge Deller <deller@gmx.de>
Fixes: c8921d72 ("parisc: Fix and improve kernel stack unwinding")

Use new return type vm_fault_t for fault handler.  For now, this is just
documenting that the function returns a VM_FAULT value rather than an
errno.  Once all instances are converted, vm_fault_t will become a
distinct type.

Ref-> commit 1c8f4220 ("mm: change return type to vm_fault_t")

In this patch all the caller of handle_mm_fault() are changed to return
vm_fault_t type.

Link: http://lkml.kernel.org/r/20180617084810.GA6730@jordon-HP-15-Notebook-PCSigned-off-by: NSouptick Joarder <jrdr.linux@gmail.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Richard Kuo <rkuo@codeaurora.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Michal Simek <monstr@monstr.eu>
Cc: James Hogan <jhogan@kernel.org>
Cc: Ley Foon Tan <lftan@altera.com>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: James E.J. Bottomley <jejb@parisc-linux.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Palmer Dabbelt <palmer@sifive.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: David S. Miller <davem@davemloft.net>
Cc: Richard Weinberger <richard@nod.at>
Cc: Guan Xuetao <gxt@pku.edu.cn>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: "Levin, Alexander (Sasha Levin)" <alexander.levin@verizon.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: NHelge Deller <deller@gmx.de>

We do support running 64-bit userspace processes, although there isn't
yet full gcc and glibc support. Anyway, fix the comments to reflect the
reality.
Signed-off-by: NHelge Deller <deller@gmx.de>

Fix the strace code path to call 64-bit syscalls in case we are
executing by a 64-bit application.
Signed-off-by: NHelge Deller <deller@gmx.de>

Executing 64-bit applications was broken. This patch restores this
support and cleans up some code paths.
Signed-off-by: NHelge Deller <deller@gmx.de>

This patchset fixes and improves stack unwinding a lot:
1. Show backward stack traces with up to 30 callsites
2. Add callinfo to ENTRY_CFI() such that every assembler function will get an
   entry in the unwind table
3. Use constants instead of numbers in call_on_stack()
4. Do not depend on CONFIG_KALLSYMS to generate backtraces.
5. Speed up backtrace generation

Make sure you have this patch to GNU as installed:
https://sourceware.org/ml/binutils/2018-07/msg00474.html
Without this patch, unwind info in the kernel is often wrong for various
functions.
Signed-off-by: NHelge Deller <deller@gmx.de>

Now that mb() is an instruction barrier, it will slow performance if we issue
unnecessary barriers.

The spinlock defines have a number of unnecessary barriers.  The __ldcw()
define is both a hardware and compiler barrier.  The mb() barriers in the
routines using __ldcw() serve no purpose.

The only barrier needed is the one in arch_spin_unlock().  We need to ensure
all accesses are complete prior to releasing the lock.
Signed-off-by: NJohn David Anglin <dave.anglin@bell.net>
Cc: stable@vger.kernel.org # 4.0+
Signed-off-by: NHelge Deller <deller@gmx.de>

Now that we use a sync prior to releasing the locks in syscall.S, we don't need
the PA 2.0 ordered stores used to release some locks.  Using an ordered store,
potentially slows the release and subsequent code.

There are a number of other ordered stores and loads that serve no purpose.  I
have converted these to normal stores.
Signed-off-by: NJohn David Anglin <dave.anglin@bell.net>
Cc: stable@vger.kernel.org # 4.0+
Signed-off-by: NHelge Deller <deller@gmx.de>

As part of the effort to reduce the code duplication between _THIS_IP_
and current_text_addr(), let's consolidate callers of
current_text_addr() to use _THIS_IP_.
Signed-off-by: NNick Desaulniers <ndesaulniers@google.com>
Signed-off-by: NHelge Deller <deller@gmx.de>

Some parts of the HAVE_REGS_AND_STACK_ACCESS_API feature is needed for
the rseq syscall. This patch adds the most important parts, and as long
as we don't support kprobes, we should be fine.
Signed-off-by: NHelge Deller <deller@gmx.de>

parisc is the only Linux architecture which has defined a value for ENOTSUP.
All other architectures #define ENOTSUP as EOPNOTSUPP in their libc headers.

Having an own value for ENOTSUP which is different than EOPNOTSUPP often gives
problems with userspace programs which expect both to be the same.  One such
example is a build error in the libuv package, as can be seen in
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=900237.

Since we dropped HP-UX support, there is no real benefit in keeping an own
value for ENOTSUP. This patch drops the parisc value for ENOTSUP from the
kernel sources. glibc needs no patch, it reuses the exported headers.
Signed-off-by: NHelge Deller <deller@gmx.de>

Switch to the generic noncoherent direct mapping implementation.

Fix sync_single_for_cpu to do skip the cache flush unless the transfer
is to the device to match the more tested unmap_single path which should
have the same cache coherency implications.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NHelge Deller <deller@gmx.de>

Current the S/G list based DMA ops use flush_kernel_vmap_range which
contains a few UP optimizations, while the rest of the DMA operations
uses flush_kernel_dcache_range.  The single vs sg operations are supposed
to have the same effect, so they should use the same routines.  Use
the more conservation version for now, but if people more familiar with
parisc think the vmap version is generally fine for DMA we should switch
all interfaces over to it.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NHelge Deller <deller@gmx.de>

The only difference is that pcxl supports dma coherent allocations, while
pcx only supports non-consistent allocations and otherwise fails.

But dma_alloc* is not in the fast path, and merging these two allows an
easy migration path to the generic dma-noncoherent implementation, so
do it.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NHelge Deller <deller@gmx.de>

With gcc-8 fsanitize=null become very noisy.  GCC started to complain
about things like &a->b, where 'a' is NULL pointer.  There is no NULL
dereference, we just calculate address to struct member.  It's
technically undefined behavior so UBSAN is correct to report it.  But as
long as there is no real NULL-dereference, I think, we should be fine.

-fno-delete-null-pointer-checks compiler flag should protect us from any
consequences.  So let's just no use -fsanitize=null as it's not useful
for us.  If there is a real NULL-deref we will see crash.  Even if
userspace mapped something at NULL (root can do this), with things like
SMAP should catch the issue.

Link: http://lkml.kernel.org/r/20180802153209.813-1-aryabinin@virtuozzo.comSigned-off-by: NAndrey Ryabinin <aryabinin@virtuozzo.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

For years I thought all parisc machines executed loads and stores in
order. However, Jeff Law recently indicated on gcc-patches that this is
not correct. There are various degrees of out-of-order execution all the
way back to the PA7xxx processor series (hit-under-miss). The PA8xxx
series has full out-of-order execution for both integer operations, and
loads and stores.

This is described in the following article:
http://web.archive.org/web/20040214092531/http://www.cpus.hp.com/technical_references/advperf.shtml

For this reason, we need to define mb() and to insert a memory barrier
before the store unlocking spinlocks. This ensures that all memory
accesses are complete prior to unlocking. The ldcw instruction performs
the same function on entry.
Signed-off-by: NJohn David Anglin <dave.anglin@bell.net>
Cc: stable@vger.kernel.org # 4.0+
Signed-off-by: NHelge Deller <deller@gmx.de>

Enable the -mlong-calls compiler option by default, because otherwise in most
cases linking the vmlinux binary fails due to truncations of R_PARISC_PCREL22F
relocations. This fixes building the 64-bit defconfig.

Cc: stable@vger.kernel.org # 4.0+
Signed-off-by: NHelge Deller <deller@gmx.de>

Almost all architectures include it.  Add a ARCH_NO_PREEMPT symbol to
disable preempt support for alpha, hexagon, non-coldfire m68k and
user mode Linux.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>