Thanks to Laszlo Ersek for spotting the double semicolon in target/i386/kvm.c
I have trivially grepped the tree for ';;' in C files.
Suggested-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Ladi Prosek <lprosek@redhat.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
Reading and writing to an sa_restorer member that isn't supposed to
exist corrupts user memory. Introduce TARGET_ARCH_HAS_SA_RESTORER,
similar to the kernel's __ARCH_HAS_SA_RESTORER.
Reported-by: Helge Deller <deller@gmx.de>
Signed-off-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
glibc used to have:
typedef struct ucontext { ... } ucontext_t;
glibc now has:
typedef struct ucontext_t { ... } ucontext_t;
(See https://sourceware.org/bugzilla/show_bug.cgi?id=21457
for detail and rationale for the glibc change)
However, QEMU used "struct ucontext" in declarations. This is a
private name and compatibility cannot be guaranteed. Switch to
only using the standardized type name.
Signed-off-by: Khem Raj <raj.khem@gmail.com>
Message-id: 20170628204452.41230-1-raj.khem@gmail.com
Cc: Kamil Rytarowski <kamil@netbsd.org>
Cc: Riku Voipio <riku.voipio@iki.fi>
Cc: Laurent Vivier <laurent@vivier.eu>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
[PMM: Rewrote commit message, based mostly on the one from
Nathaniel McCallum]
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
If a signal is delivered during the execution of a delay slot,
or a gUSA region, clear those bits from the environment so that
the signal handler does not start in that same state.
Cleaning the bits on signal return is paranoid good sense.
Reviewed-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Richard Henderson <rth@twiddle.net>
Message-Id: <20170718200255.31647-10-rth@twiddle.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
We translate gUSA regions atomically in a parallel context.
But in a serial context a gUSA region may be interrupted.
In that case, restart the region as the kernel would.
Reviewed-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Richard Henderson <rth@twiddle.net>
Message-Id: <20170718200255.31647-9-rth@twiddle.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Shadow registers are part of the openrisc spec along with sr[cid], as
part of the fast context switching feature. When exceptions occur,
instead of having to save registers to the stack if enabled the CID will
increment and a new set of registers will be available.
This patch only implements shadow registers which can be used as extra
scratch registers via the mfspr and mtspr if required. This is
implemented in a way where it would be easy to add on the fast context
switching, currently cid is hardcoded to 0.
This is need for openrisc linux smp kernels to boot correctly.
Signed-off-by: Stafford Horne <shorne@gmail.com>
do_rt_sigreturn uses an uninitialised local variable instead of fetching
the old signal mask directly from the signal frame when restoring the mask,
so the signal mask is undefined after do_rt_sigreturn. As the signal
frame data is in target-endian order, target_to_host_sigset instead of
target_to_host_sigset_internal is required.
do_sigreturn is correct in using target_to_host_sigset_internal, because
get_user already did the endianness conversion.
Signed-off-by: Michael Karcher <karcher@physik.fu-berlin.de>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <20170225110517.2832-3-laurent@vivier.eu>
Use cpu_m68k_get_ccr()/cpu_m68k_set_ccr() to setup and restore correctly
the value of SR in the ucontext structure
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <20170225110517.2832-2-laurent@vivier.eu>
Note that x86_64 has only _rt signal handlers. This implementation
attempts to share code with the x86_32 implementation.
CC: Laurent Vivier <laurent@vivier.eu>
Signed-off-by: Allan Wirth <awirth@akamai.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Pranith Kumar <bobby.prani@gmail.com>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <20170226165345.8757-1-bobby.prani@gmail.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
A segfault is noticed when an emulated program uses any of ucontext
regs fields. Risu detected this issue in the following operation when
handling a signal:
ucontext_t *uc = (ucontext_t*)uc;
uc->uc_mcontext.regs->nip += 4;
but this works fine:
uc->uc_mcontext.gp_regs[PT_NIP] += 4;
This patch set regs to a valid location as well as other sigcontext
fields.
Signed-off-by: Jose Ricardo Ziviani <joserz@linux.vnet.ibm.com>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <1485900317-3256-1-git-send-email-joserz@linux.vnet.ibm.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Add missing bits for qemu-user required for emulating Altera Nios2
userspace binaries.
Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Chris Wulff <crwulff@gmail.com>
Cc: Jeff Da Silva <jdasilva@altera.com>
Cc: Ley Foon Tan <lftan@altera.com>
Cc: Sandra Loosemore <sandra@codesourcery.com>
Cc: Yves Vandervennet <yvanderv@altera.com>
Reviewed-by: Alexander Graf <agraf@suse.de>
Message-Id: <20170118220146.489-4-marex@denx.de>
Signed-off-by: Richard Henderson <rth@twiddle.net>
There were a number of bugs in the implementation:
- The structure alignment was wrong for 64-bit.
- Also 64-bit only does RT signals.
- On 64-bit, we need to put a pointer to the (aligned) vector registers
in the frame and use it for restoring
- We had endian bugs when saving/restoring vector registers
- My recent fixes for exception NIP broke sigreturn in user mode
causing us to resume one instruction too far.
- Add VSR second halves
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
struct target_ucontext_v2 is not at the begining of the signal frame,
therefore do_sigaltstack was being passed bogus arguments.
As the offset depends on the type of signal frame fixed by passing in the
beginning of the context from do_sigreturn_v2 and do_rt_sigreturn_v2.
Suggested-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Timothy Edward Baldwin <T.E.Baldwin99@members.leeds.ac.uk>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
Now that we have a force_sig() with the semantics we need,
we can implement force_sigsegv() to call it rather than
open-coding the call to queue_signal().
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
If the sigreturn syscall fails to read memory then this causes a
SIGSEGV, but this is not necessarily a fatal signal -- the guest
process can catch it.
We don't implement this correctly because the behaviour of QEMU's
force_sig() function has drifted away from the kernel function of the
same name -- ours now does "always do a guest core dump and abort
execution", whereas the kernel version simply forces the guest to
take a signal, which may or may not eventually cause a core dump.
Rename our force_sig() to dump_core_and_abort(), and provide a
force_sig() which acts more like the kernel version as the sigreturn
implementations expect it to. Since force_sig() now returns, we must
update all the callsites to return -TARGET_QEMU_ESIGRETURN so that
the main loop doesn't change the guest registers before the signal
handler is invoked.
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
The 32-bit ARM signal frame setup code was just bailing out
on error returns from lock_user_struct calls, without
generating the SIGSEGV that should happen here. Wire up
error return codes to call force_sigsegv().
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
A failed write to memory trying to set up the signal frame
should trigger a SIGSEGV, but this need not be fatal: the
guest has a chance to catch it. Implement this via a force_sigsegv()
function with the same behaviour as the kernel function of that
name: make sure that we don't try to re-take a failed SIGSEGV,
and force a synchronous signal.
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
Instead of assuming in queue_signal() that all callers are passing
a siginfo structure which uses the _sifields._sigfault part of the
union (and thus a si_type of QEMU_SI_FAULT), make callers pass
the si_type they require in as an argument.
[RV adjusted to apply]
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
In process_pending_signals() we restart the scan of possible
pending signals after calling handle_pending_signal() in
case some other signal has been generated. This rescan
should also include a check for a new synchronous signal
since those are in fact the only kind of new signal that
the signal frame setup process might produce.
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
Native strace reports when the process being traced takes a signal:
--- SIGSEGV {si_signo=SIGSEGV, si_code=SI_KERNEL, si_addr=0} ---
Report something similar when QEMU is doing its internal strace of
the guest process and is about to deliver it a signal.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
This patch is the result of coccinelle script
scripts/coccinelle/typecast.cocci
CC: Riku Voipio <riku.voipio@iki.fi>
CC: Alexander Graf <agraf@suse.de>
Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
Commit 655ed67c2a which switched synchronous signals to
benig recorded in ts->sync_signal rather than in a queue
with every other signal had a bug: we failed to clear
the flag indicating that a synchronous signal was pending
when we delivered it. This meant that we would take the signal
again and again every time the guest made a syscall.
(This is a bug introduced in my refactoring of Timothy Baldwin's
original code.)
Fix this by passing in the struct emulated_sigtable* to
handle_pending_signal(), so that we clear the pending flag
in the ts->sync_signal struct when handling a synchronous signal.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
The kernel and libc have different ideas about what a sigset_t
is -- for the kernel it is only _NSIG / 8 bytes in size (usually
8 bytes), but for libc it is much larger, 128 bytes. In most
situations the difference doesn't matter, because if you pass a
pointer to a libc sigset_t to the kernel it just acts on the first
8 bytes of it, but for the ucontext_t* argument to a signal handler
it trips us up. The kernel allocates this ucontext_t on the stack
according to its idea of the sigset_t type, but the type of the
ucontext_t defined by the libc headers uses the libc type, and
so do the manipulator functions like sigfillset(). This means that
(1) sizeof(uc->uc_sigmask) is much larger than the actual
space used on the stack
(2) sigfillset(&uc->uc_sigmask) will write garbage 0xff bytes
off the end of the structure, which can trash data that
was on the stack before the signal handler was invoked,
and may result in a crash after the handler returns
To avoid this, we use a memset() of the correct size to fill
the signal mask rather than using the libc function.
This fixes a problem where we would crash at least some of the
time on an i386 host when a signal was taken.
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>
host_to_target_siginfo() is implemented by a combination of
host_to_target_siginfo_noswap() followed by tswap_siginfo().
The first of these two functions assumes that the target_siginfo_t
it is writing to is correctly aligned, but the pointer passed
into host_to_target_siginfo() is directly from the guest and
might be misaligned. Use a local variable to avoid this problem.
(tswap_siginfo() does now correctly handle a misaligned destination.)
We have to add a memset() to host_to_target_siginfo_noswap()
to avoid some false positive "may be used uninitialized" warnings
from gcc about subfields of the _sifields union if it chooses to
inline both tswap_siginfo() and host_to_target_siginfo_noswap()
into host_to_target_siginfo().
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Signed-off-by: Peter Maydell <riku.voipio@linaro.org>
Use Coccinelle script to replace 'ret = E; return ret' with
'return E'. The script will do the substitution only when the
function return type and variable type are the same.
Manual fixups:
* audio/audio.c: coding style of "read (...)" and "write (...)"
* block/qcow2-cluster.c: wrap line to make it shorter
* block/qcow2-refcount.c: change indentation of wrapped line
* target-tricore/op_helper.c: fix coding style of
"remainder|quotient"
* target-mips/dsp_helper.c: reverted changes because I don't
want to argue about checkpatch.pl
* ui/qemu-pixman.c: fix line indentation
* block/rbd.c: restore blank line between declarations and
statements
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Message-Id: <1465855078-19435-4-git-send-email-ehabkost@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
[Unused Coccinelle rule name dropped along with a redundant comment;
whitespace touched up in block/qcow2-cluster.c; stale commit message
paragraph deleted]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
The siginfo_t struct includes a union. The correct way to identify
which fields of the union are relevant is complicated, because we
have to use a combination of the si_code and si_signo to figure out
which of the union's members are valid. (Within the host kernel it
is always possible to tell, but the kernel carefully avoids giving
userspace the high 16 bits of si_code, so we don't have the
information to do this the easy way...) We therefore make our best
guess, bearing in mind that a guest can spoof most of the si_codes
via rt_sigqueueinfo() if it likes. Once we have made our guess, we
record it in the top 16 bits of the si_code, so that tswap_siginfo()
later can use it. tswap_siginfo() then strips these top bits out
before writing si_code to the guest (sign-extending the lower bits).
This fixes a bug where fields were sometimes wrong; in particular
the LTP kill10 test went into an infinite loop because its signal
handler got a si_pid value of 0 rather than the pid of the sending
process.
As part of this change, we switch to using __put_user() in the
tswap_siginfo code which writes out the byteswapped values to
the target memory, in case the target memory pointer is not
sufficiently aligned for the host CPU's requirements.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
Block signals while emulating sigaction. This is a non-interruptible
syscall, and using block_signals() avoids races where the host
signal handler is invoked and tries to examine the signal handler
data structures while we are updating them.
Signed-off-by: Timothy Edward Baldwin <T.E.Baldwin99@members.leeds.ac.uk>
Message-id: 1441497448-32489-29-git-send-email-T.E.Baldwin99@members.leeds.ac.uk
[PMM: expanded commit message]
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
If a synchronous signal and an asynchronous signal arrive near simultaneously,
and the signal number of the asynchronous signal is lower than that of the
synchronous signal the the handler for the asynchronous would be called first,
and then the handler for the synchronous signal would be called within or
after the first handler with an incorrect context.
This is fixed by queuing synchronous signals separately. Note that this does
risk delaying a asynchronous signal until the synchronous signal handler
returns rather than handling the signal on another thread, but this seems
unlikely to cause problems for real guest programs and is unavoidable unless
we could guarantee to roll back and reexecute whatever guest instruction
caused the synchronous signal (which would be a bit odd if we've already
logged its execution, for instance, and would require careful analysis of
all guest CPUs to check it was possible in all cases).
Signed-off-by: Timothy Edward Baldwin <T.E.Baldwin99@members.leeds.ac.uk>
Message-id: 1441497448-32489-24-git-send-email-T.E.Baldwin99@members.leeds.ac.uk
[PMM: added a comment]
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
As host signals are now blocked whenever guest signals are blocked, the
queue of realtime signals is now in Linux. The QEMU queue is now
redundant and can be removed. (We already did not queue non-RT signals, and
none of the calls to queue_signal() except the one in host_signal_handler()
pass an RT signal number.)
Signed-off-by: Timothy Edward Baldwin <T.E.Baldwin99@members.leeds.ac.uk>
Message-id: 1441497448-32489-23-git-send-email-T.E.Baldwin99@members.leeds.ac.uk
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
[PMM: minor commit message tweak]
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
Both queue_signal() and process_pending_signals() did check for default
actions of signals, this is redundant and also causes fatal and stopping
signals to incorrectly cause guest system calls to be interrupted.
The code in queue_signal() is removed.
Signed-off-by: Timothy Edward Baldwin <T.E.Baldwin99@members.leeds.ac.uk>
Message-id: 1441497448-32489-21-git-send-email-T.E.Baldwin99@members.leeds.ac.uk
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
If multiple host signals are received in quick succession they would
be queued in TaskState then delivered to the guest in spite of
signals being supposed to be blocked by the guest signal handler's
sa_mask. Fix this by decoupling the guest signal mask from the
host signal mask, so we can have protected sections where all
host signals are blocked. In particular we block signals from
when host_signal_handler() queues a signal from the guest until
process_pending_signals() has unqueued it. We also block signals
while we are manipulating the guest signal mask in emulation of
sigprocmask and similar syscalls.
Blocking host signals also ensures the correct behaviour with respect
to multiple threads and the overrun count of timer related signals.
Alas blocking and queuing in qemu is still needed because of virtual
processor exceptions, SIGSEGV and SIGBUS.
Blocking signals inside process_pending_signals() protects against
concurrency problems that would otherwise happen if host_signal_handler()
ran and accessed the signal data structures while process_pending_signals()
was manipulating them.
Since we now track the guest signal mask separately from that
of the host, the sigsuspend system calls must track the signal
mask passed to them, because when we process signals as we leave
the sigsuspend the guest signal mask in force is that passed to
sigsuspend.
Signed-off-by: Timothy Edward Baldwin <T.E.Baldwin99@members.leeds.ac.uk>
Message-id: 1441497448-32489-19-git-send-email-T.E.Baldwin99@members.leeds.ac.uk
[PMM: make signal_pending a simple flag rather than a word with two flag bits;
ensure we don't call block_signals() twice in sigreturn codepaths;
document and assert() the guarantee that using do_sigprocmask() to
get the current mask never fails; use the qemu atomics.h functions
rather than raw volatile variable access; add extra commentary and
documentation; block SIGSEGV/SIGBUS in block_signals() and in
process_pending_signals() because they can't occur synchronously here;
check the right do_sigprocmask() call for errors in ssetmask syscall;
expand commit message; fixed sigsuspend() hanging]
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
All the architecture specific handlers for sigreturn include calls
to do_sigprocmask(SIGSETMASK, &set, NULL) to set the signal mask
from the uc_sigmask in the context being restored. Factor these
out into calls to a set_sigmask() function. The next patch will
want to add code which is not run when setting the signal mask
via do_sigreturn, and this change allows us to separate the two
cases.
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>
Fix a stray tab-indented linux in linux-user/signal.c.
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>
Move the handle_pending_signal() function above process_pending_signals()
to avoid the need for a forward declaration. (Whitespace only change.)
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>
Factor out the code to handle a single signal from the
process_pending_signals() function. The use of goto for flow control
is OK currently, but would get significantly uglier if extended to
allow running the handle_signal code multiple times.
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>
setup_frame()/setup_rt_frame()/restore_user_regs() are using
MSR_LE as the similar kernel functions do: as a bitmask.
But in QEMU, MSR_LE is a bit position, so change this
accordingly.
The previous code was doing nothing as MSR_LE is 0,
and "env->msr &= ~MSR_LE" doesn't change the value of msr.
And yes, a user process can change its endianness,
see linux kernel commit:
fab5db9 [PATCH] powerpc: Implement support for setting little-endian mode via prctl
and prctl(2): PR_SET_ENDIAN, PR_GET_ENDIAN
Reviewed-by: Thomas Huth <huth@tuxfamily.org>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
The return address is in target space, so the restorer address needs to
be target space, too.
Signed-off-by: Chen Gang <gang.chen.5i5j@gmail.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
The return address is in target space, so the restorer address needs to
be target space, too.
Signed-off-by: Chen Gang <gang.chen.5i5j@gmail.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
Original implementation uses do_rt_sigreturn directly in host space,
when a guest program is in unwind procedure in guest space, it will get
an incorrect restore address, then causes unwind failure.
Also cleanup the original incorrect indentation.
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Signed-off-by: Chen Gang <gang.chen.5i5j@gmail.com>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
If a signal is delivered immediately before a blocking system call the
handler will only be called after the system call returns, which may be a
long time later or never.
This is fixed by using a function (safe_syscall) that checks if a guest
signal is pending prior to making a system call, and if so does not call the
system call and returns -TARGET_ERESTARTSYS. If a signal is received between
the check and the system call host_signal_handler() rewinds execution to
before the check. This rewinding has the effect of closing the race window
so that safe_syscall will reliably either (a) go into the host syscall
with no unprocessed guest signals pending or or (b) return
-TARGET_ERESTARTSYS so that the caller can deal with the signals.
Implementing this requires a per-host-architecture assembly language
fragment.
This will also resolve the mishandling of the SA_RESTART flag where
we would restart a host system call and not call the guest signal handler
until the syscall finally completed -- syscall restarting now always
happens at the guest syscall level so the guest signal handler will run.
(The host syscall will never be restarted because if the host kernel
rewinds the PC to point at the syscall insn for a restart then our
host_signal_handler() will see this and arrange the guest PC rewind.)
This commit contains the infrastructure for implementing safe_syscall
and the assembly language fragment for x86-64, but does not change any
syscalls to use it.
Signed-off-by: Timothy Edward Baldwin <T.E.Baldwin99@members.leeds.ac.uk>
Message-id: 1441497448-32489-14-git-send-email-T.E.Baldwin99@members.leeds.ac.uk
[PMM:
* Avoid having an architecture if-ladder in configure by putting
linux-user/host/$(ARCH) on the include path and including
safe-syscall.inc.S from it
* Avoid ifdef ladder in signal.c by creating new hostdep.h to hold
host-architecture-specific things
* Added copyright/license header to safe-syscall.inc.S
* Rewrote commit message
* Added comments to safe-syscall.inc.S
* Changed calling convention of safe_syscall() to match syscall()
(returns -1 and host error in errno on failure)
* Added a long comment in qemu.h about how to use safe_syscall()
to implement guest syscalls.
]
RV: squashed Peters "fixup! linux-user: compile on non-x86-64 hosts"
patch
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Update the Microblaze main loop and sigreturn code:
* on TARGET_ERESTARTSYS, wind guest PC backwards to repeat syscall insn
* set all guest CPU state within signal.c code on sigreturn
* handle TARGET_QEMU_ESIGRETURN in the main loop as the indication
that the main loop should not touch any guest CPU state
Note that this in passing fixes a bug where we were corrupting
the guest r[3] on sigreturn with the guest's r[10] because
do_sigreturn() was returning env->regs[10] but the register for
syscall return values is env->regs[3].
Signed-off-by: Timothy Edward Baldwin <T.E.Baldwin99@members.leeds.ac.uk>
Message-id: 1441497448-32489-11-git-send-email-T.E.Baldwin99@members.leeds.ac.uk
Reviewed-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
[PMM: Commit message tweaks; drop TARGET_USE_ERESTARTSYS define;
drop whitespace changes]
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
Update the tilegx main loop and sigreturn code:
* on TARGET_ERESTARTSYS, wind guest PC backwards to repeat syscall insn
* return -TARGET_QEMU_ESIGRETURN from sigreturn rather than current R_RE
* handle TARGET_QEMU_ESIGRETURN in the main loop as the indication
that the main loop should not touch any guest CPU state
Note that this fixes a bug where a sigreturn which happened to have
an errno value in TILEGX_R_RE would incorrectly cause TILEGX_R_ERR
to get set.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
Update the CRIS main loop and sigreturn code:
* on TARGET_ERESTARTSYS, wind guest PC backwards to repeat syscall insn
* set all guest CPU state within signal.c code on sigreturn
* handle TARGET_QEMU_ESIGRETURN in the main loop as the indication
that the main loop should not touch any guest CPU state
Signed-off-by: Timothy Edward Baldwin <T.E.Baldwin99@members.leeds.ac.uk>
Message-id: 1441497448-32489-34-git-send-email-T.E.Baldwin99@members.leeds.ac.uk
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
[PMM: tweak commit message; drop TARGET_USE_ERESTARTSYS define]
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
Update the S390 main loop and sigreturn code:
* on TARGET_ERESTARTSYS, wind guest PC backwards to repeat syscall insn
* set all guest CPU state within signal.c code on sigreturn
* handle TARGET_QEMU_ESIGRETURN in the main loop as the indication
that the main loop should not touch any guest CPU state
Signed-off-by: Timothy Edward Baldwin <T.E.Baldwin99@members.leeds.ac.uk>
Message-id: 1441497448-32489-33-git-send-email-T.E.Baldwin99@members.leeds.ac.uk
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
[PMM: tweak commit message; remove stray double semicolon; drop
TARGET_USE_ERESTARTSYS define]
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
Update the M68K main loop and sigreturn code:
* on TARGET_ERESTARTSYS, wind guest PC backwards to repeat syscall insn
* set all guest CPU state within signal.c code on sigreturn
* handle TARGET_QEMU_ESIGRETURN in the main loop as the indication
that the main loop should not touch any guest CPU state
Signed-off-by: Timothy Edward Baldwin <T.E.Baldwin99@members.leeds.ac.uk>
Message-id: 1441497448-32489-32-git-send-email-T.E.Baldwin99@members.leeds.ac.uk
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
[PMM: tweak commit message; drop TARGET_USE_ERESTARTSYS define]
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
Update the Alpha main loop and sigreturn code:
* on TARGET_ERESTARTSYS, wind guest PC backwards to repeat syscall insn
* handle TARGET_QEMU_ESIGRETURN in the main loop as the indication
that the main loop should not touch any guest CPU state
Signed-off-by: Timothy Edward Baldwin <T.E.Baldwin99@members.leeds.ac.uk>
Message-id: 1441497448-32489-13-git-send-email-T.E.Baldwin99@members.leeds.ac.uk
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
[PMM: tweak commit message; drop TARGET_USE_ERESTARTSYS define;
PC is env->pc, not env->ir[IR_PV]]
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
Update the SH4 main loop and sigreturn code:
* on TARGET_ERESTARTSYS, wind guest PC backwards to repeat syscall insn
* set all guest CPU state within signal.c code on sigreturn
* handle TARGET_QEMU_ESIGRETURN in the main loop as the indication
that the main loop should not touch any guest CPU state
Signed-off-by: Timothy Edward Baldwin <T.E.Baldwin99@members.leeds.ac.uk>
Message-id: 1441497448-32489-12-git-send-email-T.E.Baldwin99@members.leeds.ac.uk
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
[PMM: tweak commit message; drop TARGET_USE_ERESTARTSYS define]
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
Update the SPARC main loop and sigreturn code:
* on TARGET_ERESTARTSYS, wind guest PC backwards to repeat syscall insn
* set all guest CPU state within signal.c code on sigreturn
* handle TARGET_QEMU_ESIGRETURN in the main loop as the indication
that the main loop should not touch any guest CPU state
Signed-off-by: Timothy Edward Baldwin <T.E.Baldwin99@members.leeds.ac.uk>
Message-id: 1441497448-32489-9-git-send-email-T.E.Baldwin99@members.leeds.ac.uk
[PMM: Commit message tweaks; drop TARGET_USE_ERESTARTSYS define]
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
Update the 32-bit and 64-bit ARM main loop and sigreturn code:
* on TARGET_ERESTARTSYS, wind guest PC backwards to repeat syscall insn
* set all guest CPU state within signal.c code on sigreturn
* handle TARGET_QEMU_ESIGRETURN in the main loop as the indication
that the main loop should not touch any guest CPU state
Signed-off-by: Timothy Edward Baldwin <T.E.Baldwin99@members.leeds.ac.uk>
Message-id: 1441497448-32489-6-git-send-email-T.E.Baldwin99@members.leeds.ac.uk
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
[PMM: tweak commit message; drop TARGET_USE_ERESTARTSYS define]
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
Update the x86 main loop and sigreturn code:
* on TARGET_ERESTARTSYS, wind guest PC backwards to repeat syscall insn
* set all guest CPU state within signal.c code rather than passing it
back out as the "return code" from do_sigreturn()
* handle TARGET_QEMU_ESIGRETURN in the main loop as the indication
that the main loop should not touch EAX
Signed-off-by: Timothy Edward Baldwin <T.E.Baldwin99@members.leeds.ac.uk>
Message-id: 1441497448-32489-5-git-send-email-T.E.Baldwin99@members.leeds.ac.uk
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
[PMM: Commit message tweaks; drop TARGET_USE_ERESTARTSYS define]
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
Some of the signal handling was a mess with a mixture of tabs and 8 space
indents.
Signed-off-by: Timothy Edward Baldwin <T.E.Baldwin99@members.leeds.ac.uk>
Message-id: 1441497448-32489-3-git-send-email-T.E.Baldwin99@members.leeds.ac.uk
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
[PMM: just rebased]
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Peter Crosthwaite <crosthwaite.peter@gmail.com>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
When linux-user code is calling cpsr_write(), use a restrictive
mask to ensure we are limiting the set of CPSR bits we update.
In particular, don't allow the mode bits to be changed.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Sergey Fedorov <serge.fdrv@gmail.com>
Message-id: 1455556977-3644-5-git-send-email-peter.maydell@linaro.org
Add an argument to cpsr_write() to indicate what kind of CPSR
write is being requested, since the exact behaviour should
differ for the different cases.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Sergey Fedorov <serge.fdrv@gmail.com>
Message-id: 1455556977-3644-3-git-send-email-peter.maydell@linaro.org
Clean up includes so that osdep.h is included first and headers
which it implies are not included manually.
This commit was created with scripts/clean-includes.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 1453832250-766-10-git-send-email-peter.maydell@linaro.org
To return from a signal, setup_frame() puts an instruction to
be executed in the stack. This sequence calls the syscall sigreturn().
The address of the instruction must be set in the PR register
to be executed.
This patch fixes this: the current code sets the register to the address
of the instruction in the host address space (which can be 64bit whereas
PR is only 32bit), but the virtual CPU can't access this address space,
so we put in PR the address of the instruction in the guest address space.
This patch also removes an useless variable (ret) in the modified functions.
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
"Unimplemented" messages go to stderr, everything else goes to tracepoints
Reviewed-by: Laurent Vivier <lvivier@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
[rth: Remove the spreg[EX1] handling, as it's irrelevant to user-mode.]
Signed-off-by: Chen Gang <gang.chen.5i5j@gmail.com>
Message-Id: <1443312618-13641-1-git-send-email-gang.chen.5i5j@gmail.com>
Signed-off-by: Richard Henderson <rth@twiddle.net>
qemu has already considered about some targets may have no traditional
signals. And openrisc's setup_frame() is dummy, but it can be supported
by setup_rt_frame().
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Chen Gang <gang.chen.5i5j@gmail.com>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
A number of files were including assert.h but not using any
of the functions it provides
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
All of the core-code usages of this API have the cpu pointer handy so
pass it in. There are only 3 architecture specific usages (2 of which
are commented out) which can just use ENV_GET_CPU() locally to get the
cpu pointer. The reduces core code usage of the CPU env, which brings
us closer to common-obj'ing these core files.
Cc: Riku Voipio <riku.voipio@iki.fi>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Eduardo Habkost <ehabkost@redhat.com>
Acked-by: Eduardo Habkost <ehabkost@redhat.com>
Signed-off-by: Peter Crosthwaite <crosthwaite.peter@gmail.com>
Signed-off-by: Andreas Färber <afaerber@suse.de>
Provide a routine to access the correct floating point register,
to simplify future expansion.
Suggested-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Eric Farman <farman@linux.vnet.ibm.com>
Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
The m68k signal frame setup code which writes the signal return
trampoline code to the stack was assuming that a 'long' was 32 bits;
on 64 bit systems this meant we would end up writing the 32 bit
(2 insn) trampoline sequence to retaddr+4,retaddr+6 instead of
the intended retaddr+0,retaddr+2, resulting in a guest crash when
it tried to execute the invalid zero-bytes at retaddr+0.
Fix by using uint32_t instead; also use uint16_t rather than short
for consistency. This fixes bug LP:1404690.
Reported-by: Michel Boaventura
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
The function copy_siginfo_to_user() just calls tswap_siginfo(), so
call the latter function directly and delete the wrapper function.
The wrapper is actually misleading since it implies that the
semantics are like the kernel function with the same name which
copies the data to a guest user-space address. In fact tswap_siginfo()
just does data-structure conversion between two structures whose
addresses are host addresses (the copy to userspace is handled
in QEMU by the lock_user/unlock_user calls).
This also fixes clang complaints about the wrapper being unused
in some configs.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
Remove the function current_exec_domain_sig(), which always returns
its argument. This was intended as a stub for supporting the kernel's
exec_domain handling, but:
* we don't have any of the other code for execution domains
* in the kernel this handling is architecture-specific, not generic
* we only call this function in the x86, ppc and sh4 signal code paths,
and the PPC one is wrong anyway because the PPC kernel doesn't
have this signal-remapping code
So it's best to simply delete the function; any future attempt to
implement exec domains will be better served by adding the correct
code from scratch based on the kernel sources at that time.
This change also fixes some clang warnings about the function being
defined but not used for some target architectures.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
Function pointers in the 64-bit ELFv2 PowerPC ABI are actual (internal)
entry point addresses. However, when invoking a function via a function
pointer, GPR 12 must also be set to this address so that the TOC may be
handled properly.
Add this support to the invocation of a signal handler.
Signed-off-by: Tom Musta <tommusta@gmail.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
Eliminate the stub for the do_setcontext() function for TARGET_PPC64. The
implementation re-uses the existing TARGET_PPC32 code with the only change
being the computation of the address of the register save area.
Signed-off-by: Tom Musta <tommusta@gmail.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
Properly dereference 64-bit PPC ELF V1 ABIT function pointers to signal handlers.
On this platform, function pointers are pointers to structures and the first 64
bits of such a structure contains the function's entry point. The second 64 bits
contains the TOC pointer, which must be placed into GPR 2.
Signed-off-by: Tom Musta <tommusta@gmail.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
Enable the 64-bit PowerPC signal handling code that was previously
disabled via #ifdefs. Specifically:
- Move the target_mcontext (register save area) structure and
append it to the 64-bit target_sigcontext structure. This
provides the space on the stack for saving and restoring
context.
- Define the target_rt_sigframe for 64-bit.
- Adjust the setup_frame and setup_rt_frame routines to properly
select the target_mcontext area and trampoline within the stack
frame; tthis is different for 32-bit and 64-bit implementations.
- Adjust the do_setcontext stub for 64-bit so that it compiles
without warnings.
The 64-bit signal handling code is still not functional after this
change; but the 32-bit code is. Subsequent changes will address
specific issues with the 64-bit code.
Signed-off-by: Tom Musta <tommusta@gmail.com>
[agraf: fix build on 32bit hosts, ppc64abi32]
Signed-off-by: Alexander Graf <agraf@suse.de>
Split the encoding of the PowerPC sigreturn trampoline from the saving of
register state onto the signal handler stack. This will make it easier
in subsequent patches to deal with variations in the stack frame layouts between
32 and 64 bit PowerPC.
Signed-off-by: Tom Musta <tommusta@gmail.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
The code that sets the stack frame back pointer is incorrect for
the setup_rt_frame() code; qemu will abort (SIGSEGV) in some
environments. The setup_frame code was fixed in commit
beb526b121 but the setup_rt_frame
code was not.
Make the setup_rt_frame code consistent with the setup_frame
code.
Signed-off-by: Tom Musta <tommusta@gmail.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
The ELF V2 ABI for PPC64 defines MINSIGSTKSZ as 4096 bytes whereas it was
2048 previously.
Signed-off-by: Tom Musta <tommusta@gmail.com>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
As reported by Laurent, which should use TARGET_SA_ONSTACK
on arm, microblaze and openrisc targets like we do on all
others. Practical matter is minimal as for almost all archs
SA_ONSTACK is 0x08000000:
http://lxr.free-electrons.com/ident?i=SA_ONSTACK
Reported-by: Laurent Desnogues <laurent.desnogues@gmail.com>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
The last remaining check for return value of __get_user.
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Cc: Alexander Graf <agraf@suse.de>
Remove checks of __get_user and the err variable
used to control flow with it.
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
As __get_user and __put_user do not return errors, remove the
if checks from around them. This allows making the save/restore
functions void.
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Cc: Alexander Graf <agraf@suse.de>
Remove "if(__put_user" checks and their related error paths
for all architecture's setup_frame, setup_rt_frame and similar.
Remove the unlock_user_struct when the only way to end up there is
from failed lock_user_struct.
Remove err variable if there are no users for it in the function
anymore.
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Remove "if(__get_user" checks and their related error paths
for all architecture's do_sigreturn. Remove the unlock_user_struct
when the only way to end up there is from failed lock_user_struct.
v3: remove unneccesary sigsegv label as suggested by Peter
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Access is already checked in the lock_user_struct
call before.
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
A function never called from anywhere, obviously half-complete.
Remove function and if someone wants to complete this, please
check the old version out of git history.
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
make most implementations of restore_sigcontext void and
remove checking it's return value from functions calling
restore_sigcontext.
The exception is the X86 version of the function that is
too different from others to deal in this way, and arm
version, to keep possibility of erroring out from failed
valid_user_regs.
v3: keep arm valid_user_regs for filling in near future.
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Make all implementations of setup_sigcontext void and
remove checking it's return value from functions calling
setup_sigcontext.
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Since copy_siginfo_to_user always returns 0, make it void
and remove any checks for return value from calling functions.
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Remove the remaining check for __put_user return
value, and all the checks for err variable which
isn't set anywhere anymore.
No we can only end up in give_sigsegv due to failed
lock_user_struct - thus we remove the unlock_user_struct
to avoid unlocking a region never locked.
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Remove all the simple cases of reading the return value
of __get_user and __put_user.
We set err = 0 in sparc versions of do_sigreturn and
sparc64_set_context to avoid compile error, but else this patch is
just general removal of err |= __get_user ... idiom.
v2: remove err variable from target_rt_restore_ucontext
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Set the fault address correctly in the signal information passed
to a signal handler for AArch64 guests.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
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>
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>
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>
Implement support for signal handlers with the SA_RESTORER
flag set.
Signed-off-by: Michael Matz <matz@suse.de>
[PMM: minor tweaks to make patch apply to current master]
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Fix the loop restoring the FP registers from the signal frame to match
the one used when setting up the signal frame, so that it handles
TARGET_WORDS_BIGENDIAN being set.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
Reviewed-by: Richard Henderson <rth@twiddle.net>
When forcing a fatal signal, we weren't initialising the sa_flags
field in the struct sigaction we used to reset the signal handler
to SIG_DFL.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
__put_user can write bytes, words (2 bytes) or longwords (4 bytes).
Here obviously words should have been written, but bytes were written,
so values like 0x9c5f were truncated to 0x5f.
Fix this by changing retcode from uint8_t to to uint16_t in
target_signal_frame and also in the unused rt_signal_frame.
This problem was reported by static code analysis (smatch).
Cc: qemu-stable@nongnu.org
Signed-off-by: Stefan Weil <sw@weilnetz.de>
Acked-by: Riku Voipio <riku.voipio@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Tested-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Reviewed-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Signed-off-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
* mjt/trivial-patches:
acpi unit-test: Remove temporary disk after test
mainstone: Fix duplicate array values for key 'space'
pxa27x: Add 'const' attribute to keyboard maps
pxa27x: Reduce size of keyboard matrix mapping
doc: Mention chardev:id in available devices for -serial
configure: Python tests must be done before help message
configure: Rewrite code for help message
fix -boot strict regressed in commit 6ef4716
vl: make boot_strict variable static (not used outside vl.c)
x86: only allow real mode to access 32bit without LMA
linux-user: Use macro TARGET_NSIG_WORDS where possible
exynos4210: Use macro ARRAY_SIZE where possible
ui/cocoa: Use macro ARRAY_SIZE where possible
misc: Use macro ARRAY_SIZE where possible
openrisc: Fix spelling in comment (transaltion -> translation)
hw/arm/highbank: Simplify code (memory region in device state)
Message-id: 1388182050-10270-1-git-send-email-mjt@msgid.tls.msk.ru
Signed-off-by: Anthony Liguori <aliguori@amazon.com>
