linux-user/signal.c: Correct error path for AArch64 do_rt_sigreturn

The error path in AArch64 do_rt_sigreturn() which fails before
attempting lock_user_struct() was doing an unlock_user_struct()
on an uninitialized variable. Initialize frame to NULL so we
can use the same error-exit path in all cases (unlock of NULL
is permitted and does nothing).

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
linux-user: Don't return uninitialized value for atomic_barrier syscall

QEMU's implementation of the m68k atomic_barrier syscall, like the kernel's,
is just a no-op. However we still need to return a result code from it.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
linux-user: implement F_[GS]ETOWN_EX

F_GETOWN is replaced by F_GETOWN_EX inside the glibc fcntl wrapper

Signed-off-by: Andreas Schwab <schwab@suse.de>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
linux-user: Don't reserve space for commpage for AArch64

AArch64 Linux, unlike AArch32, doesn't use a commpage. This means we
should not be reserving room in the guest address space for one.
Fixes LP:1287195.

Reported-by: Amanieu d'Antras <amanieu@gmail.com>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
signal: added a wrapper for sigprocmask function

Create a wrapper for signal mask changes initiated by the guest;
(this includes syscalls and also the sigreturns from signal.c)
this will give us a place to put code which prevents the guest
from changing the handling of signals used by QEMU itself
internally.

The wrapper is called from all the guest-initiated sigprocmask, but
is not called from internal qemu sigprocmask calls.

Signed-off-by: Alex Barcelo <abarcelo@ac.upc.edu>
[PMM: Added calls to wrapper for sigprocmask uses in signal.c
when setting the signal mask on entry and exit from signal
handlers, since these also are guest-provided signal masks.]
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
linux-user: Don't allow guest to block SIGSEGV

Don't allow the linux-user guest to block SIGSEGV -- QEMU needs this
signal to detect accesses to pages which it has marked read-only
because it has cached translated code from them.

We implement this by making the do_sigprocmask() wrapper suppress
SIGSEGV when doing the host process signal mask manipulation; instead
we store the current state of SIGSEGV in the TaskState struct.

If we get a SIGSEGV for the guest when the guest has blocked the
signal, we treat it as if the default SEGV handler was in place,
as the kernel does for forced SIGSEGV delivery.

This patch is based on an idea by Alex Barcelo, but rather than
simply lying to the guest about the SIGSEGV state we track it.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reported-by: Alex Barcelo <abarcelo@ac.upc.edu>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
linux-user: Implement capget, capset

Implement the capget and capset syscalls. This is useful because
simple programs like 'ls' try to use it in AArch64, and otherwise
we emit a lot of noise about it being unimplemented.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
vexpress: Set reset-cbar property for CPUs

Newer versions of the Linux kernel (as of commit bc41b8724 in 3.12)
now assume that if the CPU is a Cortex-A9 and the reset value of the
PERIPHBASE/CBAR register is zero then the CPU is a specific buggy
single core A9 SoC, and will not try to start other cores. Since we
now have a CPU property for the reset value of the CBAR, we can
just fix the vexpress board model to correctly set CBAR so SMP
works again. To avoid duplicate boilerplate code in both the A9
and A15 daughterboard init functions, we split out the CPU and
private memory region init to its own function.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reported-by: Rob Herring <rob.herring@linaro.org>
Reviewed-by: Peter Crosthwaite <peter.crosthwaite@xilinx.com>
Message-id: 1394462692-8871-2-git-send-email-peter.maydell@linaro.org
realview-pbx-a9: Set reset-cbar property for CPUs

If the CPU is a Cortex-A9 then we should set its reset-cbar property
so that the guest can read the correct PERIPHBASE/CBAR register value;
newer versions of the Linux kernel (as of commit bc41b8724 in 3.12)
will otherwise assume the CPU is a buggy single core A9 SoC. The
realview-pbx-a9 is the only one of the cluster of boards in realview.c
which works with the Cortex-A9 (ie which gets an a9mpcore_priv device);
make sure it also has reset-cbar set correctly.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Peter Crosthwaite <peter.crosthwaite@xilinx.com>
Message-id: 1394462692-8871-3-git-send-email-peter.maydell@linaro.org
exynos4210: Set reset-cbar property of Cortex-A9 CPUs

Set the reset-cbar property of the Exynos4210 SoC's Cortex-A9
CPUs, so that Linux doesn't misrecognize them as a broken
uniprocessor SoC.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Peter Crosthwaite <peter.crosthwaite@xilinx.com>
Message-id: 1394462692-8871-4-git-send-email-peter.maydell@linaro.org
virt: Set reset-cbar on CPUs

Set the reset-cbar property on CPUs used by the virt board,
if they have it. This isn't necessary for correct functioning
under Linux (since the A9 isn't a valid CPU for the virt board),
but it is the correct behaviour.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Peter Crosthwaite <peter.crosthwaite@xilinx.com>
Message-id: 1394462692-8871-5-git-send-email-peter.maydell@linaro.org
target-arm: Add ARM_CP_IO notation to PMCR reginfo

Now that the PMCR writefn makes timer accesses, its reginfo needs
the ARM_CP_IO flag, so that icount mode works correctly. (Fixes
the bug accidentally introduced in commit 7c2cb42b).

Reported-by: Laurent Desnogues <laurent.desnogues@gmail.com>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 1394908291-16546-1-git-send-email-peter.maydell@linaro.org
target-arm: A64: Implement PMULL instruction

Implement the PMULL instruction; this is the last unimplemented insn
in the three-reg-diff group.

Note that PMULL with size 3 is considered part of the AES part
of the crypto extensions (see the ID_AA64ISAR0_EL1 register definition
in the v8 ARM ARM), so it isn't necessary to burn an extra feature
bit on it, even though we're using more feature bits than a single
"crypto extension present/not present" toggle.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Message-id: 1394822294-14837-2-git-send-email-peter.maydell@linaro.org
target-arm: A64: Fix bug in add_sub_ext handling of rn

rn == 31 always means SP (not XZR) whether an add_sub_ext
instruction is setting the flags or not; only rd has behaviour
dependent on whether we are setting flags.

Reported-by: Laurent Desnogues <laurent.desnogues@gmail.com>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Message-id: 1394822294-14837-3-git-send-email-peter.maydell@linaro.org
target-arm: A64: Add last AdvSIMD Integer to FP ops

This adds the remaining [US]CVTF operations to the SIMD
shift-immediate, scalar-shift-immediate, two-reg-misc and
scalar-two-reg-misc groups of opcodes.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 1394822294-14837-4-git-send-email-peter.maydell@linaro.org
[PMM: added scalar 2-misc and scalar-shift-imm encodings]
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
target-arm: A64: Add FSQRT to C3.6.17 (two misc)

Implement FSQRT in the two-reg-misc category.
GCC uses this instruction form.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Message-id: 1394822294-14837-5-git-send-email-peter.maydell@linaro.org
target-arm: A64: Add remaining CLS/Z vector ops

Implement the CLS, CLZ operations in the 2-reg-misc category.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Message-id: 1394822294-14837-6-git-send-email-peter.maydell@linaro.org
target-arm: A64: Saturating and narrowing shift ops

This implements the remaining [US][Q][R]SHR[U][N][2] opcodes, which are
saturating and narrowing shift right operations. These are used in
things like libav. Note signed shifts can have an "unsigned" saturating
narrow operation which will floor negative values.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 1394822294-14837-7-git-send-email-peter.maydell@linaro.org
[PMM: Added the scalar encodings, style tweaks]
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
target-arm: A64: Implement SADDLP, UADDLP, SADALP, UADALP

Implement the SADDLP, UADDLP, SADALP and UADALP instructions
in the SIMD 2-reg misc category.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Message-id: 1394822294-14837-8-git-send-email-peter.maydell@linaro.org
target-arm: A64: Implement SHLL, SHLL2

Implement the SHLL and SHLL2 instructions from the 2-reg-misc
category.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Message-id: 1394822294-14837-9-git-send-email-peter.maydell@linaro.org