It is easy to waste a bunch of time when one takes a 32-bit .config
from a test machine and try to build it on a faster 64-bit system, and
its existing setting of CONFIG_64BIT=n gets *changed* to match the
build host.  Similarly, if one has an existing build tree it is easy
to trash an entire build tree that way.

This is because the default setting for $ARCH when discovered from
'uname' is one of the legacy pre-x86-merge values (i386 or x86_64),
which effectively force the setting of CONFIG_64BIT to match. We should
default to ARCH=x86 instead, finally completing the merge that we
started so long ago.

This patch preserves the behaviour of the legacy ARCH settings for commands
such as:

   make ARCH=x86_64 randconfig
   make ARCH=i386 randconfig

... since making the value of CONFIG_64BIT actually random in that situation
is not desirable.

In time, perhaps we can retire this legacy use of the old ARCH= values.
We already have a way to override values for *any* config option, using
$KCONFIG_ALLCONFIG, so it could be argued that we don't necessarily need
to keep ARCH={i386,x86_64} around as a special case just for overriding
CONFIG_64BIT.

We'd probably at least want to add a way to override config options from
the command line ('make CONFIG_FOO=y oldconfig') before we talk about doing
that though.

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Link: http://lkml.kernel.org/r/1356040315.3198.51.camel@shinybook.infradead.org


Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>

The problem occurs [1] when a kernel-mode task returns from a system
call with a pending signal.

A real-life scenario is a child of 'khelper' returning from a failed
kernel_execve() in ____call_usermodehelper() [ kernel/kmod.c ].
kernel_execve() fails due to a pending SIGKILL, which is the result of
"kill -9 -1" (at least, busybox's init does it upon reboot).

The loop is as follows:

* syscall_exit_work:
 - work_pending:            // start_of_the_loop
 - work_notifysig:
   - do_notify_resume()
     - do_signal()
       - if (!user_mode(regs)) return;
 - resume_userspace         // TIF_SIGPENDING is still set
 - work_pending             // so we call work_pending => goto
                            // start_of_the_loop

More information can be found in another LKML thread:
http://www.serverphorums.com/read.php?12,457826

[1] The problem was also reproduced on !CONFIG_VM86 x86, and the
following fix was accepted.

http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=29a2e2836ff9ea65a603c89df217f4198973a74f



Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/3571/


Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

Broken since e05ea74fc56f347f872ef9946d27c53e8bf20864 (lmo) rsp.
cea7e2df

 (kernel.org) [MIPS: Sort out CPU
type to name translation.]  These CPUs are no longer very popular to say
the least ...

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Reported-by: Murphy McCauley <murphy.mccauley@gmail.com>

This needs to use the compat entry point or it's going to fail on big
endian systems.

Noticed by Al Viro.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

By using the native syscall entry point the kernel was also expecting
64-bit iovec structures.

This is broken since ddd9e91b

 [preadv/
pwritev: MIPS: Add preadv(2) and pwritev(2) syscalls.] which originally
added these two syscalls.  I walked through piles of code, including
libc and couldn't find anything that would have worked around the issue
so this change the API to what it should always have been.

Noticed and patch suggested by Al Viro.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

Problem:

1) Huge page mapping of anonymous memory is initially invalid.  Will be
   faulted in by copy-on-write mechanism.

2) Userspace attempts store at the end of the huge mapping.

3) TLB Refill exception handler fill TLB with a normal (4K sized)
   invalid page at the end of the huge mapping virtual address range.

4) Userspace restarted, and re-attempts the store at the end of the
   huge mapping.

5) Page from #3 is invalid, we get a fault and go to the hugepage
   fault handler.  This tries to map a huge page and calls
   huge_ptep_set_access_flags() to install the mapping.

6) We just call the generic ptep_set_access_flags() to set up the page
   tables, but the flush there assumes a normal (4K sized) page and
   only tries to flush the first part of the huge page virtual address
   out of the TLB, since the existing entry from step #3 doesn't
   conflict, nothing is flushed.

7) We attempt to load the mapping into the TLB, but because it
   conflicts with the entry from step #3, we get a Machine Check
   exception.

The fix: Flush the entire rage covered by the huge page in
huge_ptep_set_access_flags(), and remove the optimization in
local_flush_tlb_range() so that the flush actually does the correct
thing.

Signed-off-by: David Daney <david.daney@cavium.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Cc: Hillf Danton <dhillf@gmail.com>
Patchwork: https://patchwork.linux-mips.org/patch/4661/


Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
(cherry picked from commit dd617f258cc39d36be26afee9912624a2d23112c)

Newer versions of binutils mark '_end' as 'B' instead of 'A' for
whatever reason.

To be honest, the piggyback code doesn't actually care what kind
of symbol _start and _end are, it just wants to find them and
record the address.

So remove the type from the match strings.

Reported-by: Aaro Koskinen <aaro.koskinen@iki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>

Reported-by: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>

In commit 9d73fc2d

 ("open*(2) compat fixes (s390, arm64)") I said:
>
> 	The usual rules for open()/openat()/open_by_handle_at() are
> 1) native 32bit - don't force O_LARGEFILE in flags
> 2) native 64bit - force O_LARGEFILE in flags
> 3) compat on 64bit host - as for native 32bit
> 4) native 32bit ABI for 64bit system (mips/n32, x86/x32) - as for native 64bit
>
> There are only two exceptions - s390 compat has open() forcing O_LARGEFILE and
> arm64 compat has open_by_handle_at() doing the same thing.  The same binaries
> on native host (s390/31 and arm resp.) will *not* force O_LARGEFILE, so IMO
> both are emulation bugs.

Three exceptions, actually - parisc open() is another case like that.
Native 32bit won't force O_LARGEFILE, the same binary on parisc64 will.

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

The usual rules for open()/openat()/open_by_handle_at() are
 1) native 32bit - don't force O_LARGEFILE in flags
 2) native 64bit - force O_LARGEFILE in flags
 3) compat on 64bit host - as for native 32bit
 4) native 32bit ABI for 64bit system (mips/n32, x86/x32) - as for
    native 64bit

There are only two exceptions - s390 compat has open() forcing
O_LARGEFILE and arm64 compat has open_by_handle_at() doing the same
thing.  The same binaries on native host (s390/31 and arm resp.) will
*not* force O_LARGEFILE, so IMO both are emulation bugs.

Objections? The fix is obvious...

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

When a cpu enters S3 state, the FPU state is lost.
After resuming for S3, if we try to lazy restore the FPU for a process running
on the same CPU, this will result in a corrupted FPU context.

Ensure that "fpu_owner_task" is properly invalided when (re-)initializing a CPU,
so nobody will try to lazy restore a state which doesn't exist in the hardware.

Tested with a 64-bit kernel on a 4-core Ivybridge CPU with eagerfpu=off,
by doing thousands of suspend/resume cycles with 4 processes doing FPU
operations running. Without the patch, a process is killed after a
few hundreds cycles by a SIGFPE.

Cc: Duncan Laurie <dlaurie@chromium.org>
Cc: Olof Johansson <olofj@chromium.org>
Cc: <stable@kernel.org> v3.4+ # for 3.4 need to replace this_cpu_write by percpu_write
Signed-off-by: Vincent Palatin <vpalatin@chromium.org>
Link: http://lkml.kernel.org/r/1354306532-1014-1-git-send-email-vpalatin@chromium.org


Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>

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

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

incidentally, declaring a local variable as __user (!) to make
sparse STFU is really sick.  Especially since sparse had been
100% right - it *is* a bug.

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

do_sigaltstack() expects _userland_ address, TYVM...

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

... or we'll end up buggering the results of ELF_PLAT_INIT()

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

Signed-off-by: Mark Salter <msalter@redhat.com>

Some internal kernel symbols were referenced in the exported setup.h.
This splits out the internal bits from the exported uapi bits.

Signed-off-by: Mark Salter <msalter@redhat.com>

The SP804 driver statically initialises the cpumask of the clock event
device to be cpu_all_mask, which is derived from the compile-time
constant NR_CPUS. This breaks SMP_ON_UP systems where the interrupt
controller handling the sp804 doesn't have the irq_set_affinity callback
on the irq_chip, because the common timer code fails to identify the
device as cpu-local and ends up treating it as a broadcast device
instead.

This patch fixes the problem by using cpu_possible_mask at runtime,
which will correctly represent the possible CPUs when SMP_ON_UP is being
used.

Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

There appear to have been some 486 clones, including the "enhanced"
version of Am486, which have CPUID but not CR4.  These 486 clones had
only the FPU flag, if any, unlike the Intel 486s with CPUID, which
also had VME and therefore needed CR4.

Therefore, look at the basic CPUID flags and require at least one bit
other than bit 0 before we modify CR4.

Thanks to Christian Ludloff of sandpile.org for confirming this as a
problem.

Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>

In __emulate_1op_rax_rdx, we use "+a" and "+d" which are input/output
constraints, and *then* use "a" and "d" as input constraints.  This is
incorrect, but happens to work on some versions of gcc.

However, it breaks gcc with -O0 and icc, and may break on future
versions of gcc.

Reported-and-tested-by: Melanie Blower <melanie.blower@intel.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Link: http://lkml.kernel.org/r/B3584E72CFEBED439A3ECA9BCE67A4EF1B17AF90@FMSMSX107.amr.corp.intel.com


Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Acked-by: Marcelo Tosatti <mtosatti@redhat.com>

A comment in entry.S incorrectly stated that interrupt vectors
called __do_IRQ() and that int6 vector was used for syscalls.
Both statements are incorrect for the current kernel, so this
patch cleans up the wording to reflect current reality.

Signed-off-by: Mark Salter <msalter@redhat.com>

C6x was mistakenly running do_notify_resume with interrupts disabled.
This would triggerlead to a warning in local_bh_enable() because interrupts
were disabled:

------------[ cut here ]------------
WARNING: at /es/linux/linux-next/kernel/softirq.c:160 local_bh_enable+0x5c/0x10c()
Modules linked in:

             e02f384d e002cda8 e02f3469 e02f384d 000000a0 e00363fc e01cce58 e5005c00
             e0327986 00000000 e63c0aec 00000164 e00363fc 00000000 fffffffe e5005c00
             e61fde00 e0268184 00000134 e01c91dc 00000001 fffffffe 00000000 10000100
             e01c80e4 e5005c00 00000000 00000000 00000000 e63c0aec e526ce00 10000100
             e628f920 e63c0a88 e6010410 e6449750 e5005c20 00000000 00000000 e63c0a80
             e5005c20 e01c8590 e63c0a80 e5005c20 e63c0aec e00a0554 e009c758 e639e860
 irq_spurious_proc_fops+0x6ad/0x3438
 warn_slowpath_common+0x8c/0xb8
 irq_spurious_proc_fops+0x2c9/0x3438
 irq_spurious_proc_fops+0x6ad/0x3438
 local_bh_enable+0x5c/0x10c
 sk_alloc+0x34/0xa4
 local_bh_enable+0x5c/0x10c
 unix_release_sock+0x5c/0x2a0
 sys_connect+0x94/0xd4
 sock_release+0x38/0x104
 sock_close+0x3c/0x54
 __fput+0x154/0x2ec
 filp_close+0xc0/0xe4
 task_work_run+0xdc/0x12c
 sys_close+0x2c/0x74
 resume_userspace+0x0/0x30
---[ end trace a70cbd610ae1f6b4 ]---

This patch enables interrupts before calling do_notify_resume().

Signed-off-by: Mark Salter <msalter@redhat.com>

While the EEH does recovery on the specific PE that has PCI errors,
the PCI devices belonging to the PE will be removed and the PE will
be marked as invalid since we still need the information stored in
the PE. We only invalidate the PE when it doesn't have associated
EEH devices and valid child PEs. However, the code used to check
that is wrong. The patch fixes that.

Signed-off-by: Gavin Shan <shangw@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

This bug-fix makes sure that of_iomap is defined extern for sparc so that the
sparc-specific implementation of_iomap is once again used when including
include/linux/of_address.h in a sparc context. OF_GPIO that is now available for
sparc relies on this.

The bug was inadvertently introduced in a850a755, "of/address: add empty static
inlines for !CONFIG_OF", that added a static dummy inline for of_iomap when
!CONFIG_OF_ADDRESS. However, CONFIG_OF_ADDRESS is never defined for sparc, but
there is a sparc-specific implementation /arch/sparc/kernel/of_device_common.c.

This fix takes the same approach as 0bce04be

 that solved the equivalent problem
for of_address_to_resource.

Signed-off-by: Andreas Larsson <andreas@gaisler.com>
Acked-by: David Miller <davem@davemloft.net>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>

A recent patch changed some irq routines from inlines to functions.
These routines are called by the tracer code. Now that they're functions,
if they are compiled for function tracing they will call the tracer
and crash the system due to infinite recursion. The fix disables
tracing in these functions by using "notrace" in the function
definition.

Signed-off-by: Al Cooper <alcooperx@gmail.com>
Reviewed-by: David Daney <david.daney@cavium.com>
Pathchwork: https://patchwork.linux-mips.org/patch/4564/


Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

Without this, we may end up with something like this in /proc/iomem:

01100000-014fffff : System RAM
  01100000-013bf48f : Kernel code
  013bf490-0149e01f : Kernel data
01500000-0c0fffff : System RAM

but the two System RAM ranges should be one single range.  This particular
case will result in kexec failure on Octeon systems if the kernel being
loaded by kexec is bigger than the already running kernel.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

Modern GCC can generate code which makes use of the CPU's native
unaligned memory access capabilities.  This is useful for the C
decompressor implementations used for unpacking compressed kernels.

This patch disables alignment faults and enables the v6 unaligned
access model on CPUs which support these features (i.e., v6 and
later), allowing full unaligned access support for C code in the
decompressor.

The decompressor C code must not be built to assume that unaligned
access works if support for v5 or older platforms is included in
the kernel.

For correct code generation, C decompressor code must always use
the get_unaligned and put_unaligned accessors when dealing with
unaligned pointers, regardless of this patch.

Signed-off-by: Dave Martin <dave.martin@linaro.org>
Acked-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

The new EEH code introduced a small regression, if the EEH PEs
are missin (which happens currently in qemu for example), it
will deref a NULL pointer in the MSI code.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

int sys32_rt_sigprocmask(int how, compat_sigset_t __user *set, compat_sigset_t __user *oset,
                                    unsigned int sigsetsize)
{
        sigset_t old_set, new_set;
        int ret;

        if (set && get_sigset32(set, &new_set, sigsetsize))

...
static int
get_sigset32(compat_sigset_t __user *up, sigset_t *set, size_t sz)
{
        compat_sigset_t s;
        int r;

        if (sz != sizeof *set) panic("put_sigset32()");

In other words, rt_sigprocmask(69, (void *)69, 69) done by 32bit process
will promptly panic the box.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Cc: <stable@vger.kernel.org>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

The ixp4xx queue manager uses "const struct qmgr_regs __iomem *" as the
type for a pointer that is passed to __raw_writel, which is not
allowed because of the const-ness.

Dropping the 'const' keyword fixes the problem. While we're here,
let's also drop the useless type cast.

Without this patch, building ixp4xx_defconfig results in:

In file included from arch/arm/mach-ixp4xx/ixp4xx_qmgr.c:15:0:
arch/arm/mach-ixp4xx/include/mach/qmgr.h: In function 'qmgr_put_entry':
arch/arm/mach-ixp4xx/include/mach/qmgr.h:96:2: warning: passing argument 2 of '__raw_writel' discards 'const' qualifier from pointer target type [enabled by default]
arch/arm/include/asm/io.h:88:91: note: expected 'volatile void *' but argument is of type 'const u32 *'
In file included from drivers/net/ethernet/xscale/ixp4xx_eth.c:41:0:
arch/arm/mach-ixp4xx/include/mach/qmgr.h: In function 'qmgr_put_entry':
arch/arm/mach-ixp4xx/include/mach/qmgr.h:96:2: warning: passing argument 2 of '__raw_writel' discards 'const' qualifier from pointer target type [enabled by default]
arch/arm/include/asm/io.h:88:91: note: expected 'volatile void *' but argument is of type 'const u32 *'
arch/arm/mach-ixp4xx/ixp4xx_qmgr.c: In function 'qmgr_set_irq':
arch/arm/mach-ixp4xx/ixp4xx_qmgr.c:41:9: warning: passing argument 2 of '__raw_writel' discards 'const' qualifier from pointer target type [enabled by default]
arch/arm/include/asm/io.h:88:91: note: expected 'volatile void *' but argument is of type 'const u32 *'

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Krzysztof Hałasa <khc@pm.waw.pl>

Signed-off-by: Krzysztof Hałasa <khc@pm.waw.pl>

It doesn't make much sense to map QMgr dynamically - we almost always need it
and the static mapping will be needed for little-endian data-coherent operation
(to make QMgr region value-coherent).

Signed-off-by: Krzysztof Hałasa <khc@pm.waw.pl>

Cc: Krzysztof Halasa <khc@pm.waw.pl>
Cc: Imre Kaloz <kaloz@openwrt.org>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: linux-arm-kernel@lists.infradead.org
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
Signed-off-by: Krzysztof Hałasa <khc@pm.waw.pl>

Signed-off-by: Krzysztof Hałasa <khc@pm.waw.pl>

Signed-off-by: Krzysztof Hałasa <khc@pm.waw.pl>

Signed-off-by: Krzysztof Hałasa <khc@pm.waw.pl>

Commit 97ee9f01 (ARM: OMAP: fix the ads7846 init code) have enabled the
pendown GPIO debounce time setting by the below sequence:

  gpio_request_one()
  gpio_set_debounce()
  gpio_free()

It also revealed a bug in the OMAP GPIO handling code which prevented
the GPIO debounce clock to be disabled and CORE transition to low power
states.

Commit c9c55d92

 (gpio/omap: fix off-mode bug: clear debounce settings on
free/reset) fixes the OMAP GPIO handling code by making sure that the
GPIO debounce clock gets disabled if no GPIO is requested from current
bank.

While fixing the OMAP GPIO handling code (in the right way), the above
commit makes the gpio_request->set_debounce->free sequence invalid as
after freeing the GPIO, the debounce settings are lost.

Fix the debounce settings by moving the debounce initialization to the
actual GPIO requesting code - the ads7846 driver.

Signed-off-by: Igor Grinberg <grinberg@compulab.co.il>
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

- The code relies on rc_pci_fixup being called, which only happens
  when CONFIG_PCI_QUIRKS is enabled, so add that to Kconfig. Omitting
  this causes a booting failure with a non-obvious cause.
- Update rc_pci_fixup to set the class properly, copying the
  more modern style from other places
- Correct the rc_pci_fixup comment

Signed-off-by: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
Cc: stable@vger.kernel.org
Signed-off-by: Jason Cooper <jason@lakedaemon.net>

PMU interrupts start at IRQ_DOVE_PMU_START, not IRQ_DOVE_PMU_START + 1.
Fix the condition.  (It may have been less likely to occur had the code
been written "if (irq >= IRQ_DOVE_PMU_START" which imho is the easier
to understand notation, and matches the normal way of thinking about
these things.)

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Cc: stable@vger.kernel.org
Signed-off-by: Jason Cooper <jason@lakedaemon.net>