Enforce 32 bit types for all compat syscall argument types.

This way we can make sure that all arguments get correct sign
or zero extension. Otherwise incorrect code would be generated.

E.g. for a 'long' type the COMPAT_SYSCALL_DEFINE macro wouldn't
generate code that would cause sign extension of the passed in 32
bit user space parameter.
This can cause quite subtle bugs like e.g. the one that was fixed
with dfd948e3 "fs/compat: fix parameter handling for compat
readv/writev syscalls".
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>

Some fs compat system calls have unsigned long parameters instead of
compat_ulong_t.
In order to allow the COMPAT_SYSCALL_DEFINE macro generate code that
performs proper zero and sign extension convert all 64 bit parameters
their corresponding 32 bit counterparts.

compat_sys_io_getevents() is a bit different: the non-compat version
has signed parameters for the "min_nr" and "nr" parameters while the
compat version has unsigned parameters.
So change this as well. For all practical purposes this shouldn't make
any difference (doesn't fix a real bug).
Also introduce a generic compat_aio_context_t type which can be used
everywhere.
The access_ok() check within compat_sys_io_getevents() got also removed
since the non-compat sys_io_getevents() should be able to handle
everything anyway.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>

The preadv64/pwrite64 have been implemented for the x32 ABI, in order
to allow passing 64 bit arguments from user space without splitting
them into two 32 bit parameters, like it would be necessary for usual
compat tasks.
Howevert these two system calls are only being used for the x32 ABI,
so add __ARCH_WANT_COMPAT defines for these two compat syscalls and
make these two only visible for x86.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>

Parameter conversion within the system call wrappers is only needed
for parameters which differ in size and have a size of eight bytes on
64 bit.
For system call parameters with a size of less than eight byte the
called system call itself will perform parameter conversion anyway.
So we can save the double conversion of e.g. int parameters.

The only types which need to be converted are therefore pointer and
(unsigned) long parameters.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>

Instead of explicitly changing compat system call parameters from e.g.
unsigned long to compat_ulong_t let the COMPAT_SYSCALL_WRAP macros
automatically detect (unsigned) long parameters and zero and sign
extend them automatically.
The resulting binary is completely identical.

In addition add a sys_[system call name] prototype for each system call
wrapper. This will cause compile errors if the prototype does not match
the prototype in include/linux/syscall.h.
Therefore we should now always get the correct zero and sign extension
of system call parameters. Pointers are handled like before.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>

The compat syscall wrappers for sync_file_range and fallocate merged 32 bit
parameters into 64 bit parameters. Therefore they did more than just the
usual zero and/or sign extension of system call parameters.

So convert these two wrappers to full s390 specific compat sytem calls.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>

Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>

Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>

Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>

Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>

Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>

Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>

Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>

Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>

Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>

Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>

Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>

Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>

Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>

Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>

Introduce a new compat_wrap.c file which contains the s390 specific compat
system call wrappers.
The s390 specific system call wrappers only perform sign, zero and pointer
conversion of system call arguments before actually calling the non-compat
system call.

Therefore introduce COMPAT_SYSCALL_WRAPx macros which generate C code that
is nearly identical to the assembly code. This has the advantage that the
compile will generate correct code, and we avoid the frequent copy-paste
errors seen in the compat_wrapper.S file.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>

Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>

Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>

Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>

Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>

Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>

Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>

Convert s390 specific system calls to to the new COMPAT_SYSCALL_DEFINE macro.
This allows us to get rid of the assembly compat wrappers.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>

For architecture dependent compat syscalls in common code an architecture
must define something like __ARCH_WANT_<WHATEVER> if it wants to use the
code.
This however is not true for compat_sys_getdents64 for which architectures
must define __ARCH_OMIT_COMPAT_SYS_GETDENTS64 if they do not want the code.

This leads to the situation where all architectures, except mips, get the
compat code but only x86_64, arm64 and the generic syscall architectures
actually use it.

So invert the logic, so that architectures actively must do something to
get the compat code.

This way a couple of architectures get rid of otherwise dead code.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>

Commit fb4a9602 (arm64: kernel: fix per-cpu offset restore on
resume) uses per_cpu_offset() unconditionally during CPU wakeup,
however, this is only defined for the SMP case.
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>
Reported-by: NDave P Martin <Dave.Martin@arm.com>

Page table entries on ARM64 are 64 bits, and some pte functions such as
pte_dirty return a bitwise-and of a flag with the pte value. If the
flag to be tested resides in the upper 32 bits of the pte, then we run
into the danger of the result being dropped if downcast.

For example:
	gather_stats(page, md, pte_dirty(*pte), 1);
where pte_dirty(*pte) is downcast to an int.

This patch adds a double logical invert to all the pte_ accessors to
ensure predictable downcasting.
Signed-off-by: NSteve Capper <steve.capper@linaro.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>

We need to unmangle the full address, not just the register
number, and we also need to support the real indirect bit
being set for in-kernel uses.
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
CC: <stable@vger.kernel.org> [v3.13]

The OPAL firmware functions opal_xscom_read and opal_xscom_write
take a 64-bit argument for the XSCOM (PCB) address in order to
support the indirect mode on P8.
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
CC: <stable@vger.kernel.org> [v3.13]

As Ben suggested, the patch prints PHB diag-data with multiple
fields in one line and omits the line if the fields of that
line are all zero.

With the patch applied, the PHB3 diag-data dump looks like:

PHB3 PHB#3 Diag-data (Version: 1)

  brdgCtl:     00000002
  RootSts:     0000000f 00400000 b0830008 00100147 00002000
  nFir:        0000000000000000 0030006e00000000 0000000000000000
  PhbSts:      0000001c00000000 0000000000000000
  Lem:         0000000000100000 42498e327f502eae 0000000000000000
  InAErr:      8000000000000000 8000000000000000 0402030000000000 0000000000000000
  PE[  8] A/B: 8480002b00000000 8000000000000000

[ The current diag data is so big that it overflows the printk
  buffer pretty quickly in cases when we get a handful of errors
  at once which can happen. --BenH
]
Signed-off-by: NGavin Shan <shangw@linux.vnet.ibm.com>
CC: <stable@vger.kernel.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

The PHB diag-data is important to help locating the root cause for
EEH errors such as frozen PE or fenced PHB. However, the EEH core
enables IO path by clearing part of HW registers before collecting
this data causing it to be corrupted.

This patch fixes this by dumping the PHB diag-data immediately when
frozen/fenced state on PE or PHB is detected for the first time in
eeh_ops::get_state() or next_error() backend.
Signed-off-by: NGavin Shan <shangw@linux.vnet.ibm.com>
CC: <stable@vger.kernel.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

The new ELFv2 little-endian ABI increases the stack redzone -- the
area below the stack pointer that can be used for storing data --
from 288 bytes to 512 bytes.  This means that we need to allow more
space on the user stack when delivering a signal to a 64-bit process.

To make the code a bit clearer, we define new USER_REDZONE_SIZE and
KERNEL_REDZONE_SIZE symbols in ptrace.h.  For now, we leave the
kernel redzone size at 288 bytes, since increasing it to 512 bytes
would increase the size of interrupt stack frames correspondingly.

Gcc currently only makes use of 288 bytes of redzone even when
compiling for the new little-endian ABI, and the kernel cannot
currently be compiled with the new ABI anyway.

In the future, hopefully gcc will provide an option to control the
amount of redzone used, and then we could reduce it even more.

This also changes the code in arch_compat_alloc_user_space() to
preserve the expanded redzone.  It is not clear why this function would
ever be used on a 64-bit process, though.
Signed-off-by: NPaul Mackerras <paulus@samba.org>
CC: <stable@vger.kernel.org> [v3.13]
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

The branch target should be the func addr, not the addr of func_descr_t.
So using ppc_function_entry() to generate the right target addr.
Signed-off-by: NLiu Ping Fan <pingfank@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

In copy_oldmem_page, the current check using max_pfn and min_low_pfn to
decide if the page is backed or not, is not valid when the memory layout is
not continuous.

This happens when running as a QEMU/KVM guest, where RTAS is mapped higher
in the memory. In that case max_pfn points to the end of RTAS, and a hole
between the end of the kdump kernel and RTAS is not backed by PTEs. As a
consequence, the kdump kernel is crashing in copy_oldmem_page when accessing
in a direct way the pages in that hole.

This fix relies on the memblock's service memblock_is_region_memory to
check if the read page is part or not of the directly accessible memory.
Signed-off-by: NLaurent Dufour <ldufour@linux.vnet.ibm.com>
Tested-by: NMahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
CC: <stable@vger.kernel.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Currently we're storing a host endian RTAS token in
rtas_stop_self_args.token.  We then pass that directly to rtas.  This is
fine on big endian however on little endian the token is not what we
expect.

This will typically result in hitting:
	panic("Alas, I survived.\n");

To fix this we always use the stop-self token in host order and always
convert it to be32 before passing this to rtas.
Signed-off-by: NTony Breeds <tony@bakeyournoodle.com>
Cc: stable@vger.kernel.org
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Commit e504c909 (kvm, vmx: Fix lazy FPU on nested guest, 2013-11-13)
highlighted a real problem, but the fix was subtly wrong.

nested_read_cr0 is the CR0 as read by L2, but here we want to look at
the CR0 value reflecting L1's setup.  In other words, L2 might think
that TS=0 (so nested_read_cr0 has the bit clear); but if L1 is actually
running it with TS=1, we should inject the fault into L1.

The effective value of CR0 in L2 is contained in vmcs12->guest_cr0, use
it.

Fixes: e504c909Reported-by: NKashyap Chamarty <kchamart@redhat.com>
Reported-by: NStefan Bader <stefan.bader@canonical.com>
Tested-by: NKashyap Chamarty <kchamart@redhat.com>
Tested-by: NAnthoine Bourgeois <bourgeois@bertin.fr>
Cc: stable@vger.kernel.org
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>