configure: Flip default of target_nptl

Most targets either (a) support threading or (b) don't have a
linux-user/bsd-user target, so make it default to 'yes', with those
targets that don't support threading having to specifically say so.

This is a mechanical no-behaviour-change commit; some of the
"no" entries it adds will be taken out in later patches.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
configure: Don't say target_nptl="no" if there is no linux-user target

For architectures with no linux-user target, don't claim no NPTL
support. This has no behavioural change, but it means that we
won't accidentally add a new linux-user target without threading
support in future (because attempting to do so would be a compile
failure rather than a silent lack of support).

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
configure: Enable threading on all ppc and mips linux-user targets

Though threading (target_nptl) was enabled on the base PPC and MIPS
targets, it wasn't enabled for the variants mipsn32, mipsn32el,
mips64, mips64el, ppc64 or ppc46abi32 (probably an oversight).
Enable threading consistently on all these targets.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
configure: Enable threading for unicore32-linux-user

unicore32-linux-user provides cpu_set_tls(), so the failure
to enable target_nptl was presumably an oversight. Enable it.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
linux-user: Move includes of target-specific headers to end of qemu.h

The target-specific headers (target_cpu.h and target_signal.h)
might need to use the target-independent structure and function
definitions of qemu.h; so include them only at the bottom of
qemu.h, not the top.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
linux-user: Enable NPTL for OpenRISC

The OpenRISC kernel ignores CLONE_SETTLS in its copy_thread()
implementation, so a cpu_set_tls() implementation is a no-op.
cpu_clone_regs() was setting the syscall return value in the
wrong register -- it is gpr[11], not gpr[2]. With these two
things fixed, we can compile with NPTL enabled.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Jia Liu <proljc@gmail.com>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
linux-user: Enable NPTL for SPARC targets

Provide the missing cpu_set_tls(), and resolve the FIXME in
cpu_clone_regs() by clearing the carry flag for the child.
This allows us to turn on building with NPTL for SPARC.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
linux-user: Enable NPTL for m68k

For m68k, per-thread data is a purely kernel construct with no
CPU level support. Implement it via a field in the TaskState structure,
used by cpu_set_tls() and the set_thread_area/get_thread_area
syscalls. This allows us to enable compilation with NPTL.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by:  Laurent Vivier <laurent@vivier.eu>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
linux-user: Add missing 'break' in i386 get_thread_area syscall

The i386 code for the get_thread_area syscall was missing a
'break' which meant it would have fallen through into the
implementation of the following syscall; add it.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
linux-user: Clean up handling of clone() argument order

Linux manages to have three separate orderings of the arguments to
the clone() syscall on different architectures. In the kernel these
are selected via CONFIG_CLONE_BACKWARDS and CONFIG_CLONE_BACKWARDS2.
Clean up our implementation of this to use similar #define names
rather than a TARGET_* ifdef ladder.

This includes behaviour changes fixing bugs on cris, x86-64, m68k,
openrisc and unicore32.  cris had explicit but wrong handling; the
others were just incorrectly using QEMU's default, which happened
to be the equivalent of CONFIG_CLONE_BACKWARDS. (unicore32 appears
to be broken in the mainline kernel in that it tries to use arg3 for
both parent_tidptr and newtls simultaneously -- we don't attempt
to emulate this bug...)

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
linux-user: Add i386 TLS setter

We can easily set the TLS on i386. Add code to do so.

Signed-off-by: Alexander Graf <agraf@suse.de>
[PMM: also remove "target_nptl=no" line from configure, for
 consistency with other patches in this series]
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
linux-user: Enable NPTL for x86-64

Add x86-64 implementation of cpu_set_tls() (like the kernel, we
just have to call do_arch_prctl() to set FS); this allows us to
enable NPTL.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
configure: Make NPTL non-optional

Now all linux-user targets support building with NPTL, we can make it
mandatory. This is a good idea because:
 * NPTL is no longer new and experimental; it is completely standard
 * in practice, linux-user without NPTL is nearly useless for
   binaries built against non-ancient glibc
 * it allows us to delete the rather untested code for handling
   the non-NPTL configuration

Note that this patch leaves the CONFIG_USE_NPTL ifdefs in the
bsd-user codebase alone. This makes no change for bsd-user, since
our configure test for NPTL had a "#include <linux/futex.h>"
which means bsd-user would never have been compiled with
CONFIG_USE_NPTL defined, and it still is not.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
linux-user: Avoid conditional cpu_reset()

Some CPUs reset as part of cpu_init(), some others were reset
afterwards, some not at all. While some targets didn't implement a
cpu_[state_]reset() function, QOM cpu_reset() is always available.
There's nothing wrong with resetting twice on startup, so drop
the #ifdef.

Suggested-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Andreas Färber <afaerber@suse.de>
Cc: Eduardo Habkost <ehabkost@redhat.com>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
linux-user: Fix target_stat and target_stat64 for OpenRISC

OpenRISC uses the asm-generic versions of target_stat and
target_stat64, but it was incorrectly using the x86/ARM/etc version
due to a misplaced defined(TARGET_OPENRISC).  The previously unused
OpenRISC section of the ifdef ladder also defined an incorrect
target_stat and omitted the target_stat64 definition.  Fix
target_stat, provide target_stat64, and add a comment noting that
these are the asm-generic versions for the benefit of future ports.

Reviewed-by: Jia Liu <proljc@gmail.com>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
linux-user: Fix pipe syscall return for SPARC

SPARC is one of the CPUs which has a funny syscall ABI for the
pipe syscall; add it to the set of special cases in do_pipe().

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
linux-user: fix segmentation fault passing with h2g(x) != x

When forwarding a segmentation fault into the guest process, we were passing
the host's address directly into the guest process's signal descriptor.

That obviously confused the guest process, since it didn't know what to make
of the (usually 32-bit truncated) address. Passing in h2g(address) makes the
guest process a lot happier.

To make the code more obvious, introduce a h2g_nocheck() macro that does the
same as h2g(), but allows us to convert addresses that may be outside of guest
mapped range into the guest's view of address space.

This fixes java running in arm-linux-user for me.

Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
linux-user: Fix epoll on ARM hosts

The epoll emulation uses data structures without packing them, so the
compiler might choose to add padding inside.

This patch makes the most offending one (target_epoll_event) a packed
structure to make sure we don't pad it by accident. ARM would pad it,
so declare the padding mandatory for ARM targets.

This fixes i386-on-ARM epoll emulation for me.

Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
linux-user: Reset copied CPUs in cpu_copy() always

When a new thread gets created, we need to reset non arch specific state to
get the new CPU into clean state.

However this reset should happen before the arch specific CPU contents get
copied over. Otherwise we end up having clean reset state in our newly created
thread.

Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
linux-user: Unlock mmap_lock when resuming guest from page_unprotect

The page_unprotect() function is running everything locked. Before every
potential exit path of the function mmap_unlock() gets called to make sure
we don't leak the lock.

However, the function calls tb_invalidate_phys_page() which again can
exit a signal through longjmp, leaving our mmap_unlock() attempts in vain.

Add a hint to tb_invalidate_phys_page() that we need to unlock before we
can leave back into guest context, so that we don't leak the lock.

This fixes 16-bit i386 wine programs running in linux-user for me.

Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>