Add dtb files to build targets and let kbuild handle them. Thus,
special dtbs rules can be removed. This eases Makefiles and the
implementation of the support of vendor dtb subdirectories.
Signed-off-by: NRobert Richter <rrichter@cavium.com>

Move dtbs install rules to Makefile.dtbinst. This change is needed to
implement support for dts vendor subdirs. The change makes Makefiles
easier and smaller as no longer the dtbs_install rule needs to be
defined. Another advantage is that install goals are not encoded in
targets anymore (%.dtb_dtbinst_).
Signed-off-by: NRobert Richter <rrichter@cavium.com>

This adds the dtbs_install make target to arm64. The target has been
introduced already to arch/arm with the following commit:

 f4d4ffc0 kbuild: dtbs_install: new make target

Implementation for arm64 is the same as for arm.

With 'dtbs_install' all config enabled dtb files are installed to
either the INSTALL_DTBS_PATH directory or the default location:

 $INSTALL_PATH/dtbs/$KERNELRELEASE
Signed-off-by: NRobert Richter <rrichter@cavium.com>

This breaks the stack end corruption detection facility.

What that facility does it write a magic value to "end_of_stack()"
and checking to see if it gets overwritten.

"end_of_stack()" is "task_thread_info(p) + 1", which for sparc64 is
the beginning of the FPU register save area.

So once the user uses the FPU, the magic value is overwritten and the
debug checks trigger.

Fix this by making the size explicit.

Due to the size we use for the fpsaved[], gsr[], and xfsr[] arrays we
are limited to 7 levels of FPU state saves.  So each FPU register set
is 256 bytes, allocate 256 * 7 for the fpregs area.
Reported-by: NMeelis Roos <mroos@linux.ee>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Every path that ends up at do_sparc64_fault() must install a valid
FAULT_CODE_* bitmask in the per-thread fault code byte.

Two paths leading to the label winfix_trampoline (which expects the
FAULT_CODE_* mask in register %g4) were not doing so:

1) For pre-hypervisor TLB protection violation traps, if we took
   the 'winfix_trampoline' path we wouldn't have %g4 initialized
   with the FAULT_CODE_* value yet.  Resulting in using the
   TLB_TAG_ACCESS register address value instead.

2) In the TSB miss path, when we notice that we are going to use a
   hugepage mapping, but we haven't allocated the hugepage TSB yet, we
   still have to take the window fixup case into consideration and
   in that particular path we leave %g4 not setup properly.

Errors on this sort were largely invisible previously, but after
commit 4ccb9272 ("sparc64: sun4v TLB
error power off events") we now have a fault_code mask bit
(FAULT_CODE_BAD_RA) that triggers due to this bug.

FAULT_CODE_BAD_RA triggers because this bit is set in TLB_TAG_ACCESS
(see #1 above) and thus we get seemingly random bus errors triggered
for user processes.

Fixes: 4ccb9272 ("sparc64: sun4v TLB error power off events")
Reported-by: NMeelis Roos <mroos@linux.ee>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

CR4 isn't constant; at least the TSD and PCE bits can vary.

TBH, treating CR0 and CR3 as constant scares me a bit, too, but it looks
like it's correct.

This adds a branch and a read from cr4 to each vm entry.  Because it is
extremely likely that consecutive entries into the same vcpu will have
the same host cr4 value, this fixes up the vmcs instead of restoring cr4
after the fact.  A subsequent patch will add a kernel-wide cr4 shadow,
reducing the overhead in the common case to just two memory reads and a
branch.
Signed-off-by: NAndy Lutomirski <luto@amacapital.net>
Acked-by: NPaolo Bonzini <pbonzini@redhat.com>
Cc: stable@vger.kernel.org
Cc: Petr Matousek <pmatouse@redhat.com>
Cc: Gleb Natapov <gleb@kernel.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Commit e7dbfe34 ("kprobes/x86: Move ftrace-based kprobe code
into kprobes-ftrace.c") switched from using
ARCH_SUPPORTS_KPROBES_ON_FTRACE to CONFIG_KPROBES_ON_FTRACE but
missed removing the define.
Signed-off-by: NAnton Blanchard <anton@samba.org>
Cc: masami.hiramatsu.pt@hitachi.com
Cc: ananth@in.ibm.com
Cc: a.p.zijlstra@chello.nl
Cc: fweisbec@gmail.com
Cc: rostedt@goodmis.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: NIngo Molnar <mingo@kernel.org>

Explicitly set the dr_mode for the second dwc3 controller on the
Arndale Octa board to host mode. This is required to ensure the
controller is initialized in the right mode if the kernel is build
with USB gadget support.
Reported-By: NAndreas Faerber <afaerber@suse.de>
Signed-off-by: NSjoerd Simons <sjoerd.simons@collabora.co.uk>
Signed-off-by: NKukjin Kim <kgene.kim@samsung.com>

In case the optional dr_mode property isn't set in the dwc3 nodes the
the controller will go into OTG mode if both USB host and USB gadget
functionality are enabled in the kernel configuration. Unfortunately
this results in USB not working on exynos5420-peach-pit and
exynos5800-peach-pi with such a kernel configuration unless manually
change the mode. To resolve that explicitly configure the dual role
mode as host.
Signed-off-by: NSjoerd Simons <sjoerd.simons@collabora.co.uk>
Reviewed-by: NAndreas Faerber <afaerber@suse.de>
Signed-off-by: NKukjin Kim <kgene.kim@samsung.com>

The EIRSR and ELRSR registers are 32-bit registers on GICv2, and we
store these as an array of two such registers on the vgic vcpu struct.
However, we access them as a single 64-bit value or as a bitmap pointer
in the generic vgic code, which breaks BE support.

Instead, store them as u64 values on the vgic structure and do the
word-swapping in the assembly code, which already handles the byte order
for BE systems.
Tested-by: NVictor Kamensky <victor.kamensky@linaro.org>
Acked-by: NMarc Zyngier <marc.zyngier@arm.com>
Signed-off-by: NChristoffer Dall <christoffer.dall@linaro.org>

CM-QS600 is a APQ8064 based computer on module.
The details are available at
http://compulab.co.il/products/computer-on-modules/cm-qs600/Signed-off-by: NMike Rapoport <mike.rapoport@gmail.com>
Acked-by: NIgor Grinberg <grinberg@compulab.co.il>
Signed-off-by: NKumar Gala <galak@codeaurora.org>

This DTS has support for the Sony Xperia Z1 phone (codenamed Honami).
This first version of the DTS supports just a serial console.
Signed-off-by: NTim Bird <tim.bird@sonymobile.com>
Tested-by: NKevin Hilman <khilman@linaro.org>
Signed-off-by: NKumar Gala <galak@codeaurora.org>

Add SATA PHY and SATA AHCI controller nodes to device tree to enable
generic ahci support on the IPQ8064/AP148 board.
Signed-off-by: NKumar Gala <galak@codeaurora.org>

Commit 0b0b0893 "of/pci: Fix the conversion of IO ranges into IO
resources" changed the behaviour of of_pci_range_to_resource().

Previously it simply populated the resource based on the arguments. Now
it calls pci_register_io_range() and pci_address_to_pio(). These both
have two implementations depending on whether PCI_IOBASE is defined,
which it is not for powerpc.

Further complicating matters, both routines are weak, and powerpc
implements it's own version of one - pci_address_to_pio(). However
powerpc's implementation depends on other initialisations which are done
later in boot.

The end result is incorrectly initialised IO space. Often we can get
away with that, because we don't make much use of IO space. However
virtio requires it, so we see eg:

  pci_bus 0000:00: root bus resource [io  0xffff] (bus address [0xffffffffffffffff-0xffffffffffffffff])
  PCI: Cannot allocate resource region 0 of device 0000:00:01.0, will remap
  virtio-pci 0000:00:01.0: can't enable device: BAR 0 [io  size 0x0020] not assigned

The simplest fix for now is to just stop using of_pci_range_to_resource(),
and open-code the original implementation, that's all we want it to do.

Fixes: 0b0b0893 ("of/pci: Fix the conversion of IO ranges into IO resources")
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

Commit:
b8865767 ARM: KVM: user_mem_abort: support stage 2 MMIO page mapping

introduced some code in user_mem_abort that failed to compile if
STRICT_MM_TYPECHECKS was enabled.

This patch fixes up the failing comparison.
Signed-off-by: NSteve Capper <steve.capper@linaro.org>
Reviewed-by: NKim Phillips <kim.phillips@linaro.org>
Signed-off-by: NChristoffer Dall <christoffer.dall@linaro.org>

Commit 97a13e52 ('net: phy: mdio-sun4i: don't select REGULATOR') removed
the select of REGULATOR, which means that it now has to be explicitly
enabled in the defconfig or things won't work very well.

In particular, this fixes a problem with SD/MMC not probing on my A31-based
board.

Cc: Beniamino Galvani <b.galvani@gmail.com>
Signed-off-by: NOlof Johansson <olof@lixom.net>

The AES loops in arch/sparc/crypto/aes_glue.c use a scheme where the
key material is preloaded into the FPU registers, and then we loop
over and over doing the crypt operation, reusing those pre-cooked key
registers.

There are intervening blkcipher*() calls between the crypt operation
calls.  And those might perform memcpy() and thus also try to use the
FPU.

The sparc64 kernel FPU usage mechanism is designed to allow such
recursive uses, but with a catch.

There has to be a trap between the two FPU using threads of control.

The mechanism works by, when the FPU is already in use by the kernel,
allocating a slot for FPU saving at trap time.  Then if, within the
trap handler, we try to use the FPU registers, the pre-trap FPU
register state is saved into the slot.  Then at trap return time we
notice this and restore the pre-trap FPU state.

Over the long term there are various more involved ways we can make
this work, but for a quick fix let's take advantage of the fact that
the situation where this happens is very limited.

All sparc64 chips that support the crypto instructiosn also are using
the Niagara4 memcpy routine, and that routine only uses the FPU for
large copies where we can't get the source aligned properly to a
multiple of 8 bytes.

We look to see if the FPU is already in use in this context, and if so
we use the non-large copy path which only uses integer registers.

Furthermore, we also limit this special logic to when we are doing
kernel copy, rather than a user copy.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NIyappan Subramanian <isubramanian@apm.com>
Signed-off-by: NKeyur Chudgar <kchudgar@apm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

1.
JIT compiler using multi-pass approach to converge to final image size,
since x86 instructions are variable length. It starts with large
gaps between instructions (so some jumps may use imm32 instead of imm8)
and iterates until total program size is the same as in previous pass.
This algorithm works only if program size is strictly decreasing.
Programs that use LD_ABS insn need additional code in prologue, but it
was not emitted during 1st pass, so there was a chance that 2nd pass would
adjust imm32->imm8 jump offsets to the same number of bytes as increase in
prologue, which may cause algorithm to erroneously decide that size converged.
Fix it by always emitting largest prologue in the first pass which
is detected by oldproglen==0 check.
Also change error check condition 'proglen != oldproglen' to fail gracefully.

2.
while staring at the code realized that 64-byte buffer may not be enough
when 1st insn is large, so increase it to 128 to avoid buffer overflow
(theoretical maximum size of prologue+div is 109) and add runtime check.

Fixes: 62258278 ("net: filter: x86: internal BPF JIT")
Reported-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NAlexei Starovoitov <ast@plumgrid.com>
Tested-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When creating or moving a memslot, make sure the IPA space is within the
addressable range of the guest.  Otherwise, user space can create too
large a memslot and KVM would try to access potentially unallocated page
table entries when inserting entries in the Stage-2 page tables.
Acked-by: NCatalin Marinas <catalin.marinas@arm.com>
Acked-by: NMarc Zyngier <marc.zyngier@arm.com>
Signed-off-by: NChristoffer Dall <christoffer.dall@linaro.org>

This patch adds the necessary support for all host kernel PGSIZE and
VA_SPACE configuration options for both EL2 and the Stage-2 page tables.

However, for 40bit and 42bit PARange systems, the architecture mandates
that VTCR_EL2.SL0 is maximum 1, resulting in fewer levels of stage-2
pagge tables than levels of host kernel page tables.  At the same time,
systems with a PARange > 42bit, we limit the IPA range by always setting
VTCR_EL2.T0SZ to 24.

To solve the situation with different levels of page tables for Stage-2
translation than the host kernel page tables, we allocate a dummy PGD
with pointers to our actual inital level Stage-2 page table, in order
for us to reuse the kernel pgtable manipulation primitives.  Reproducing
all these in KVM does not look pretty and unnecessarily complicates the
32-bit side.

Systems with a PARange < 40bits are not yet supported.

 [ I have reworked this patch from its original form submitted by
   Jungseok to take the architecture constraints into consideration.
   There were too many changes from the original patch for me to
   preserve the authorship.  Thanks to Catalin Marinas for his help in
   figuring out a good solution to this challenge.  I have also fixed
   various bugs and missing error code handling from the original
   patch. - Christoffer ]
Reviewed-by: NCatalin Marinas <catalin.marinas@arm.com>
Acked-by: NMarc Zyngier <marc.zyngier@arm.com>
Signed-off-by: NJungseok Lee <jungseoklee85@gmail.com>
Signed-off-by: NChristoffer Dall <christoffer.dall@linaro.org>

They're already provided by <asm/sections.h>.
Signed-off-by: NGeert Uytterhoeven <geert@linux-m68k.org>
Cc: "Luck, Tony" <tony.luck@intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: NGeert Uytterhoeven <geert@linux-m68k.org>
Acked-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Use watchdog_enable_hardlockup_detector() to set hard lockup detection's
default value to false.  It's risky to run this detection in a guest, as
false positives are easy to trigger, especially if the host is
overcommitted.
Signed-off-by: NUlrich Obergfell <uobergfe@redhat.com>
Signed-off-by: NAndrew Jones <drjones@redhat.com>
Signed-off-by: NDon Zickus <dzickus@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

If all the nodes are marked hotpluggable, alloc node data will fail.
Because __next_mem_range_rev() will skip the hotpluggable memory
regions.  numa_clear_kernel_node_hotplug() is called after alloc node
data.

numa_init()
    ...
    ret = init_func();  // this will mark hotpluggable flag from SRAT
    ...
    memblock_set_bottom_up(false);
    ...
    ret = numa_register_memblks(&numa_meminfo);  // this will alloc node data(pglist_data)
    ...
    numa_clear_kernel_node_hotplug();  // in case all the nodes are hotpluggable
    ...

numa_register_memblks()
    setup_node_data()
        memblock_find_in_range_node()
            __memblock_find_range_top_down()
                for_each_mem_range_rev()
                    __next_mem_range_rev()

This patch moves numa_clear_kernel_node_hotplug() into
numa_register_memblks(), clear kernel node hotpluggable flag before
alloc node data, then alloc node data won't fail even all the nodes
are hotpluggable.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: NXishi Qiu <qiuxishi@huawei.com>
Cc: Dave Jones <davej@redhat.com>
Cc: Tang Chen <tangchen@cn.fujitsu.com>
Cc: Gu Zheng <guz.fnst@cn.fujitsu.com>
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>

The kernel used to contain two functions for length-delimited,
case-insensitive string comparison, strnicmp with correct semantics and
a slightly buggy strncasecmp.  The latter is the POSIX name, so strnicmp
was renamed to strncasecmp, and strnicmp made into a wrapper for the new
strncasecmp to avoid breaking existing users.

To allow the compat wrapper strnicmp to be removed at some point in the
future, and to avoid the extra indirection cost, do
s/strnicmp/strncasecmp/g.
Signed-off-by: NRasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Russell King <linux@arm.linux.org.uk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

x86_64 allnoconfig:

arch/x86/kernel/cpu/common.c:968: warning: 'syscall32_cpu_init' defined but not used

Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Use the optimized ioresource lookup, "region_is_ram", for the ioremap
function.  If the region is not found, it falls back to the
"page_is_ram" function.  If it is found and it is RAM, then the usual
warning message is issued, and the ioremap operation is aborted.
Otherwise, the ioremap operation continues.
Signed-off-by: NMike Travis <travis@sgi.com>
Acked-by: NAlex Thorlton <athorlton@sgi.com>
Reviewed-by: NCliff Wickman <cpw@sgi.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Mark Salter <msalter@redhat.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

David Howells brought to my attention the mails generated by kbuild test
bot and following sparse warnings were present.  This patch fixes these
warnings.

  arch/x86/kernel/kexec-bzimage64.c:270:5: warning: symbol 'bzImage64_probe' was not declared. Should it be static?
  arch/x86/kernel/kexec-bzimage64.c:328:6: warning: symbol 'bzImage64_load' was not declared. Should it be static?
  arch/x86/kernel/kexec-bzimage64.c:517:5: warning: symbol 'bzImage64_cleanup' was not declared. Should it be static?
  arch/x86/kernel/kexec-bzimage64.c:531:5: warning: symbol 'bzImage64_verify_sig' was not declared. Should it be static?
  arch/x86/kernel/kexec-bzimage64.c:546:23: warning: symbol 'kexec_bzImage64_ops' was not declared. Should it be static?
Signed-off-by: NVivek Goyal <vgoyal@redhat.com>
Reported-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add a check if crashk_res_low exists just like GART region does.  If
crashk_res_low doesn't exist, calling exclude_mem_range is unnecessary.

Meanwhile, since crashk_res_low has been initialized at definition, it's
safe just use "if (crashk_low_res.end)" to check if it's exist.  And this
can make it consistent with other places of check.
Signed-off-by: NBaoquan He <bhe@redhat.com>
Acked-by: NVivek Goyal <vgoyal@redhat.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Make the Makefile of kexec purgatory be consistent with others in linux
src tree, and make it look generic and simple.
Signed-off-by: NBaoquan He <bhe@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Fix wrong compatible string of Exynos3250 RTC (Real-Time Clock) dt node.
The RTC of Exynos3250 must need additional source clock (XrtcXTI).
Signed-off-by: NChanwoo Choi <cw00.choi@samsung.com>
Acked-by: NKyungmin Park <kyungmin.park@samsung.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Kukjin Kim <kgene.kim@samsung.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

alloc_bootmem and related functions never return NULL. Thus a NULL
test or memset after calls to these functions is unnecessary.

The following Coccinelle semantic patch was used for making the change:

@@
expression E;
statement S;
@@

E = \(alloc_bootmem\|alloc_bootmem_low\|alloc_bootmem_pages\|alloc_bootmem_low_pages\)(...)
... when != E
- if (E == NULL) S
Signed-off-by: NHimangi Saraogi <himangi774@gmail.com>
Acked-by: NJulia Lawall <julia.lawall@lip6.fr>
Signed-off-by: NRichard Weinberger <richard@nod.at>

Add stacktrace support for User Mode Linux
Signed-off-by: NDaniel Walter <dwalter@google.com>
Signed-off-by: NRichard Weinberger <richard@nod.at>

Starting with Linux 3.12 processes get stuck in D state forever in
UserModeLinux under sync heavy workloads. This bug was introduced by
commit 805f11a0 (um: ubd: Add REQ_FLUSH suppport).
Fix bug by adding a check if FLUSH request was successfully submitted to
the I/O thread and keeping the FLUSH request on the request queue on
submission failures.

Fixes: 805f11a0 (um: ubd: Add REQ_FLUSH suppport)
Signed-off-by: NThorsten Knabe <linux@thorsten-knabe.de>
Cc: stable@kernel.org # >= 3.12
Signed-off-by: NRichard Weinberger <richard@nod.at>

1) uml kernel bootmem managed through bootmem_data->node_bootmem_map,
not the struct page array, so the array is unnecessary.

2) the bootmem struct page array has been pointed by a *local* pointer,
struct page *map, in init_maps function. The array can be accessed only
in init_maps's scope. As a result, uml kernel wastes about 1% of total
memory.
Signed-off-by: NHonggang Li <enjoymindful@gmail.com>
Signed-off-by: NRichard Weinberger <richard@nod.at>

arch/x86/um/checksum_32.S had been copy & paste from x86. When build
x86 uml, csum_partial_copy_generic_i386 mess up the exception table.
In fact, exception table dose not work in uml kernel.

And csum_partial_copy_generic_i386 never been called. So, delete it.
Signed-off-by: NHonggang Li <enjoymindful@gmail.com>
Signed-off-by: NRichard Weinberger <richard@nod.at>

There is really no point in faulting in memory regions page by page
if they are not backed by demand paged system RAM but by a linear
passthrough mapping of a host MMIO region. So instead, detect such
regions at setup time and install the mappings for the backing all
at once.
Acked-by: NMarc Zyngier <marc.zyngier@arm.com>
Reviewed-by: NChristoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: NChristoffer Dall <christoffer.dall@linaro.org>

This patch reduces the value of SIGRTMIN on PARISC from 37 to 32, thus
increasing the number of available RT signals and bring it in sync with other
Linux architectures.

Historically we wanted to natively support HP-UX 32bit binaries with the
PA-RISC Linux port.  Because of that we carried the various available signals
from HP-UX (e.g. SIGEMT and SIGLOST) and folded them in between the native
Linux signals.  Although this was the right decision at that time, this
required us to increase SIGRTMIN to at least 37 which left us with 27 (64-37)
RT signals.

Those 27 RT signals haven't been a problem in the past, but with the upcoming
importance of systemd we now got the problem that systemd alloctes (hardcoded)
signals up to SIGRTMIN+29 which is beyond our NSIG of 64. Because of that we
have not been able to use systemd on the PARISC Linux port yet.

Of course we could ask the systemd developers to not use those hardcoded
values, but this change is very unlikely, esp. with PA-RISC being a niche
architecture.

The other possibility would be to increase NSIG to e.g. 128, but this would
mean to duplicate most of the existing Linux signal handling code into the
parisc specific Linux kernel tree which would most likely introduce lots of new
bugs beside the code duplication.

The third option is to drop some HP-UX signals and shuffle some other signals
around to bring SIGRTMIN to 32.  This is of course an ABI change, but testing
has shown that existing Linux installations are not visibly affected by this
change - most likely because we move those signals around which are rarely used
and move them to slots which haven't been used in Linux yet. In an existing
installation I was able to exchange either the Linux kernel or glibc (or both)
without affecting the boot process and installed applications.

Dropping the HP-UX signals isn't an issue either, since support for HP-UX was
basically dropped a few months back with Kernel 3.14 in commit
f5a408d5 already, when we changed EWOULDBLOCK
to be equal to EAGAIN.

So, even if this is an ABI change, it's better to change it now and thus bring
PARISC Linux in sync with other architectures to avoid other issues in the
future.
Signed-off-by: NHelge Deller <deller@gmx.de>
Cc: Carlos O'Donell <carlos@systemhalted.org>
Cc: John David Anglin <dave.anglin@bell.net>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Aaro Koskinen <aaro.koskinen@iki.fi>
Cc: PARISC Linux Kernel Mailinglist <linux-parisc@vger.kernel.org>
Tested-by: NAaro Koskinen <aaro.koskinen@iki.fi>

Inconsistently, the raw_* IRQ routines do not interact with and update
the irqflags tracing and lockdep state, whereas the raw_* spinlock
interfaces do.

This causes problems in p1275_cmd_direct() because we disable hardirqs
by hand using raw_local_irq_restore() and then do a raw_spin_lock()
which triggers a lockdep trace because the CPU's hw IRQ state doesn't
match IRQ tracing's internal software copy of that state.

The CPU's irqs are disabled, yet current->hardirqs_enabled is true.

====================
reboot: Restarting system
------------[ cut here ]------------
WARNING: CPU: 0 PID: 1 at kernel/locking/lockdep.c:3536 check_flags+0x7c/0x240()
DEBUG_LOCKS_WARN_ON(current->hardirqs_enabled)
Modules linked in: openpromfs
CPU: 0 PID: 1 Comm: systemd-shutdow Tainted: G        W      3.17.0-dirty #145
Call Trace:
 [000000000045919c] warn_slowpath_common+0x5c/0xa0
 [0000000000459210] warn_slowpath_fmt+0x30/0x40
 [000000000048f41c] check_flags+0x7c/0x240
 [0000000000493280] lock_acquire+0x20/0x1c0
 [0000000000832b70] _raw_spin_lock+0x30/0x60
 [000000000068f2fc] p1275_cmd_direct+0x1c/0x60
 [000000000068ed28] prom_reboot+0x28/0x40
 [000000000043610c] machine_restart+0x4c/0x80
 [000000000047d2d4] kernel_restart+0x54/0x80
 [000000000047d618] SyS_reboot+0x138/0x200
 [00000000004060b4] linux_sparc_syscall32+0x34/0x60
---[ end trace 5c439fe81c05a100 ]---
possible reason: unannotated irqs-off.
irq event stamp: 2010267
hardirqs last  enabled at (2010267): [<000000000049a358>] vprintk_emit+0x4b8/0x580
hardirqs last disabled at (2010266): [<0000000000499f08>] vprintk_emit+0x68/0x580
softirqs last  enabled at (2010046): [<000000000045d278>] __do_softirq+0x378/0x4a0
softirqs last disabled at (2010039): [<000000000042bf08>] do_softirq_own_stack+0x28/0x40
Resetting ...
====================

Use local_* variables of the hw IRQ interfaces so that IRQ tracing sees
all of our changes.
Reported-by: NMeelis Roos <mroos@linux.ee>
Tested-by: NMeelis Roos <mroos@linux.ee>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>