We missed out on a couple of exception types that may
legitimately be raised by a userland program.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220421151735.31996-59-richard.henderson@linaro.org>

The exception return address for nios2 is the instruction
after the one that was executing at the time of the exception.

We have so far implemented this by advancing the pc during the
process of raising the exception.  It is perhaps a little less
confusing to do this advance in the translator (and helpers)
when raising the exception in the first place, so that we may
more closely match kernel sources.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Message-Id: <20220421151735.31996-58-richard.henderson@linaro.org>

Indirect branches, plus eret and bret optionally raise
an exception when branching to a misaligned address.
The exception is required when an mmu is enabled, but
enable it always because the fallback behaviour is not
documented (though presumably it discards low bits).

For the purposes of the linux-user cpu loop, if EXCP_UNALIGN
(misaligned data) were to arrive, it would be treated the
same as EXCP_UNALIGND (misaligned destination).  See the
!defined(CONFIG_NIOS2_ALIGNMENT_TRAP) block in kernel/traps.c.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220421151735.31996-53-richard.henderson@linaro.org>

Division may (optionally) raise a division exception.
Since the linux kernel has been prepared for this for
some time, enable it by default.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220421151735.31996-42-richard.henderson@linaro.org>

Drop the set of estatus in init_thread; it was clearly intended
to be setting the value of CR_STATUS for the application, but we
never actually performed that copy.  However, the proper value is
set in nios2_cpu_reset so we don't need to do anything here.

We only initialize SP and EA in init_thread, there's no value in
copying other uninitialized data into ENV.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220421151735.31996-21-richard.henderson@linaro.org>

It is cleaner to have a separate name for this variable.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220421151735.31996-17-richard.henderson@linaro.org>

Use the simpler signal interface, which forces us to supply
the missing PC value to si_addr.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Message-Id: <20220421151735.31996-13-richard.henderson@linaro.org>

Since f5ef0e51, we have a real page mapped for kuser,
which means the special casing for SIGSEGV can go away.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Message-Id: <20220421151735.31996-11-richard.henderson@linaro.org>

Drop the kernel-specific "pr2" code structure and use
the qemu-specific error return value.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220421151735.31996-8-richard.henderson@linaro.org>

There is no sigreturn syscall, only rt_sigreturn.
This function is unused.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220421151735.31996-7-richard.henderson@linaro.org>

Honor QEMU_ESIGRETURN and QEMU_ERESTARTSYS.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220421151735.31996-6-richard.henderson@linaro.org>

Follow the kernel assembly, which considers all negative
return values to be errors.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220421151735.31996-5-richard.henderson@linaro.org>

Syscall 0 is __NR_io_setup for this target; there is nothing
to work around.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Fixes: a0a839b6 ("nios2: Add usermode binaries emulation")
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220421151735.31996-4-richard.henderson@linaro.org>

The child side of clone needs to set the secondary
syscall return value, r7, to indicate syscall success.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220421151735.31996-3-richard.henderson@linaro.org>

Note that this advance *should* be done by the translator, as
that's the pc value that's supposed to be generated by hardware.
However, that's a much larger change across sysemu as well.

In the meantime, produce the correct PC for any signals raised
by the trap instruction.  Note the special case of TRAP_BRKPT,
which itself is special cased within the kernel.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220421151735.31996-2-richard.henderson@linaro.org>

Bool is a more appropriate type for this value.
Adjust the assignments to use true/false.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

G_NORETURN was introduced in glib 2.68, fallback to G_GNUC_NORETURN in
glib-compat.

Note that this attribute must be placed before the function declaration
(bringing a bit of consistency in qemu codebase usage).

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Warner Losh <imp@bsdimp.com>
Message-Id: <20220420132624.2439741-20-marcandre.lureau@redhat.com>

Suggested-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Warner Losh <imp@bsdimp.com>
Message-Id: <20220420132624.2439741-7-marcandre.lureau@redhat.com>

This header only defines the tcg_allowed variable and the tcg_enabled()
function - which are not required in many files that include this
header. Drop the #include statement there.

Signed-off-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20220315144107.1012530-1-thuth@redhat.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

Perform all logfile setup in one step.

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220417183019.755276-30-richard.henderson@linaro.org>

We have extra stuff to log at the same time.
Hoist the qemu_log_lock/unlock to the caller and use fprintf.

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220417183019.755276-23-richard.henderson@linaro.org>

Do not force exit within qemu_set_log; return bool and pass
an Error value back up the stack as per usual.

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220417183019.755276-5-richard.henderson@linaro.org>

This buffering was introduced during the Paleozoic: 9fa3e853.

There has never been an explanation as to why we may not allow
glibc to allocate the file buffer itself.  We certainly have
many other uses of mmap and malloc during user-only startup,
so presumably whatever the issue was, it has been fixed during
the preceeding 18 years.

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220417183019.755276-2-richard.henderson@linaro.org>

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20220323155743.1585078-33-marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Replace the global variables with inlined helper functions. getpagesize() is very
likely annotated with a "const" function attribute (at least with glibc), and thus
optimization should apply even better.

This avoids the need for a constructor initialization too.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20220323155743.1585078-12-marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Convert the TARGET_WORDS_BIGENDIAN macro, similarly to what was done
with HOST_BIG_ENDIAN. The new TARGET_BIG_ENDIAN macro is either 0 or 1,
and thus should always be defined to prevent misuse.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Suggested-by: Halil Pasic <pasic@linux.ibm.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220323155743.1585078-8-marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Replace a config-time define with a compile time condition
define (compatible with clang and gcc) that must be declared prior to
its usage. This avoids having a global configure time define, but also
prevents from bad usage, if the config header wasn't included before.

This can help to make some code independent from qemu too.

gcc supports __BYTE_ORDER__ from about 4.6 and clang from 3.2.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
[ For the s390x parts I'm involved in ]
Acked-by: Halil Pasic <pasic@linux.ibm.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220323155743.1585078-7-marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Coverity warns that we shift a 32-bit value by N, and then
accumulate it into a 64-bit type (target_ulong on ppc64).

The ccr is always 8 * 4-bit fields, and thus is always a
32-bit quantity; narrow the type to avoid the warning.

Fixes: Coverity CID 1487223
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20220401191643.330393-1-richard.henderson@linaro.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>

Seen while compiling on Alpine:

 In file included from ../linux-user/strace.c:17:
 In file included from ../linux-user/qemu.h:11:
 In file included from ../linux-user/syscall_defs.h:1247:
 ../linux-user/sh4/termbits.h:276:10: warning: 'TIOCSER_TEMT' macro redefined
  [-Wmacro-redefined]
 # define TIOCSER_TEMT    0x01   /* Transmitter physically empty */
          ^
 /usr/include/sys/ioctl.h:50:9: note: previous definition is here
 #define TIOCSER_TEMT 1
         ^
 1 warning generated.

Add the TARGET_ prefix here, too, like we do it on the other architectures.

Signed-off-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Reviewed-by: Yoshinori Sato <ysato@users.sourceforge.jp>
Message-Id: <20220330134302.979686-1-thuth@redhat.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>

If CONFIG_ATOMIC64, we can use a host cmpxchg and provide
atomicity across processes; otherwise we have no choice but
to continue using start/end_exclusive.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220323005839.94327-4-richard.henderson@linaro.org>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>

The existing implementation using start/end_exclusive
does not provide atomicity across processes.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220323005839.94327-3-richard.henderson@linaro.org>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>

This fallback syscall was stubbed out.
It would only matter for emulating pre-armv6.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220323005839.94327-2-richard.henderson@linaro.org>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>

Signed-off-by: Fergus Henderson <fergus@google.com>
Signed-off-by: Patrick Venture <venture@google.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20220310192148.1696486-1-venture@google.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>

Unblocked signals are never delivered, because we
didn't record the new mask for process_pending_signals.
Handle this with the same mechanism as sigsuspend.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <20220315084308.433109-6-richard.henderson@linaro.org>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>

Unblocked signals are never delivered, because we
didn't record the new mask for process_pending_signals.
Handle this with the same mechanism as sigsuspend.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <20220315084308.433109-5-richard.henderson@linaro.org>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>

Unblocked signals are never delivered, because we
didn't record the new mask for process_pending_signals.
Handle this with the same mechanism as sigsuspend.

Resolves: https://gitlab.com/qemu-project/qemu/-/issues/834


Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <20220315084308.433109-4-richard.henderson@linaro.org>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>

Two new functions: process_sigsuspend_mask and finish_sigsuspend_mask.
Move the size check and copy-from-user code.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <20220315084308.433109-3-richard.henderson@linaro.org>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>

On alpha, the sigset argument for sigsuspend is in a register.
When we drop that into memory that happens in host-endianness,
but target_to_host_old_sigset will treat it as target-endianness.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <20220315084308.433109-2-richard.henderson@linaro.org>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>

The MIPS n32 ABI is basically n64 with the address space (i.e. pointer
width) shrinked to 32 bits. Meanwhile the current code treats it as
o32-like based on TARGET_ABI_BITS, which causes problems with n32
syscalls utilizing 64-bit offsets, like pread64, affecting most (if not
all) recently built n32 binaries.

This partially solves issue #909 ("qemu-mipsn32(el) user mode emulator
fails to execute any recently built n32 binaries"); with this change
applied, the built qemu-mipsn32el is able to progress beyond the
pread64, and finish _dl_start_user for the "getting ld.so load libc.so"
case. The program later dies with SIGBUS, though, due to _dl_start_user
not maintaining stack alignment after removing ld.so itself from argv,
and qemu-user starting to enforce alignment recently, but that is
orthogonal to the issue here; the more common case of chrooting is
working, verified with my own-built Gentoo n32 sysroot. (Depending on
the exact ISA used, one may have to explicitly specify QEMU_CPU, which
is the case for my chroot.)

Buglink: https://gitlab.com/qemu-project/qemu/-/issues/909


Signed-off-by: WANG Xuerui <xen0n@gentoo.org>
Cc: Laurent Vivier <laurent@vivier.eu>
Cc: Philippe Mathieu-Daudé <f4bug@amsat.org>
Cc: Jiaxun Yang <jiaxun.yang@flygoat.com>
Cc: Andreas K. Hüttel <dilfridge@gentoo.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20220320052259.1610883-1-xen0n@gentoo.org>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>

g_new(T, n) is neater than g_malloc(sizeof(T) * n).  It's also safer,
for two reasons.  One, it catches multiplication overflowing size_t.
Two, it returns T * rather than void *, which lets the compiler catch
more type errors.

This commit only touches allocations with size arguments of the form
sizeof(T).

Patch created mechanically with:

    $ spatch --in-place --sp-file scripts/coccinelle/use-g_new-etc.cocci \
	     --macro-file scripts/cocci-macro-file.h FILES...

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Acked-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Message-Id: <20220315144156.1595462-4-armbru@redhat.com>
Reviewed-by: Pavel Dovgalyuk <Pavel.Dovgalyuk@ispras.ru>