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2016-06-07linux-user: Block signals during sigaction() handlingTimothy E Baldwin
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>
2016-06-07linux-user: Queue synchronous signals separatelyTimothy E Baldwin
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>
2016-06-07linux-user: Remove real-time signal queuingTimothy E Baldwin
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>
2016-06-07linux-user: Remove redundant default action check in queue_signal()Timothy E Baldwin
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>
2016-06-07linux-user: Fix race between multiple signalsPeter Maydell
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>
2016-06-07linux-user: Use safe_syscall for sigsuspend syscallsPeter Maydell
Use the safe_syscall wrapper for sigsuspend syscalls. This means that we will definitely deliver a signal that arrives before we do the sigsuspend call, rather than blocking first and delivering afterwards. 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>
2016-06-07linux-user: Define macro for size of host kernel sigset_tPeter Maydell
Some host syscalls take an argument specifying the size of a host kernel's sigset_t (which isn't necessarily the same as that of the host libc's type of that name). Instead of hardcoding _NSIG / 8 where we do this, define and use a SIGSET_T_SIZE macro. 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>
2016-06-07linux-user: Factor out uses of do_sigprocmask() from sigreturn codePeter Maydell
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>
2016-06-07linux-user: Fix stray tab-indentPeter Maydell
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>
2016-06-07linux-user: Move handle_pending_signal() to avoid need for declarationPeter Maydell
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>
2016-06-07linux-user: Factor out handle_signal code from process_pending_signals()Peter Maydell
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>
2016-06-07linux-user: check if NETLINK_ROUTE is availableLaurent Vivier
Some IFLA_* symbols can be missing in the host linux/if_link.h, but as they are enums and not "#defines", check in "configure" if last known (IFLA_PROTO_DOWN) is available and if not, disable management of NETLINK_ROUTE protocol. Signed-off-by: Laurent Vivier <laurent@vivier.eu> Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
2016-06-07linux-user: add netlink auditLaurent Vivier
This is, for instance, needed to log in a container. Without this, the user cannot be identified and the console login fails with "Login incorrect". Signed-off-by: Laurent Vivier <laurent@vivier.eu> Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
2016-06-07linux-user: support netlink protocol NETLINK_KOBJECT_UEVENTLaurent Vivier
This is the protocol used by udevd to manage kernel events. Signed-off-by: Laurent Vivier <laurent@vivier.eu> Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
2016-06-07linux-user: add rtnetlink(7) supportLaurent Vivier
rtnetlink is needed to use iproute package (ip addr, ip route) and dhcp client. Examples: Without this patch: # ip link Cannot open netlink socket: Address family not supported by protocol # ip addr Cannot open netlink socket: Address family not supported by protocol # ip route Cannot open netlink socket: Address family not supported by protocol # dhclient eth0 Cannot open netlink socket: Address family not supported by protocol Cannot open netlink socket: Address family not supported by protocol With this patch: # ip link 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN mode DEFAULT link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 51: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP mode DEFAULT qlen 1000 link/ether 00:16:3e:89:6b:d7 brd ff:ff:ff:ff:ff:ff # ip addr show eth0 51: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP qlen 1000 link/ether 00:16:3e:89:6b:d7 brd ff:ff:ff:ff:ff:ff inet 192.168.122.197/24 brd 192.168.122.255 scope global eth0 valid_lft forever preferred_lft forever inet6 fe80::216:3eff:fe89:6bd7/64 scope link valid_lft forever preferred_lft forever # ip route default via 192.168.122.1 dev eth0 192.168.122.0/24 dev eth0 proto kernel scope link src 192.168.122.197 # ip addr flush eth0 # ip addr add 192.168.122.10 dev eth0 # ip addr show eth0 51: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP qlen 1000 link/ether 00:16:3e:89:6b:d7 brd ff:ff:ff:ff:ff:ff inet 192.168.122.10/32 scope global eth0 valid_lft forever preferred_lft forever # ip route add 192.168.122.0/24 via 192.168.122.10 # ip route 192.168.122.0/24 via 192.168.122.10 dev eth0 Signed-off-by: Laurent Vivier <laurent@vivier.eu> Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
2016-05-27linux-user,target-ppc: fix use of MSR_LELaurent Vivier
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>
2016-05-27linux-user/signal.c: Use s390 target space address instead of host spaceChen Gang
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>
2016-05-27linux-user/signal.c: Use target address instead of host address for ↵Chen Gang
microblaze restorer 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>
2016-05-27linux-user/signal.c: Generate opcode data for restorer in setup_rt_frameChen Gang
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>
2016-05-27linux-user: arm: Remove ARM_cpsr and similar #definesPeter Maydell
The #defines of ARM_cpsr and friends in linux-user/arm/target-syscall.h can clash with versions in the system headers if building on an ARM or AArch64 build (though this seems to be dependent on the version of the system headers). The QEMU defines are not very useful (it's not clear that they're intended for use with the target_pt_regs struct rather than (say) the CPUARMState structure) and we only use them in one function in elfload.c anyway. So just remove the #defines and directly access regs->uregs[]. Reported-by: Christopher Covington <cov@codeaurora.org> Tested-by: Christopher Covington <cov@codeaurora.org> Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
2016-05-27linux-user: Use direct syscalls for setuid(), etcPeter Maydell
On Linux the setuid(), setgid(), etc system calls have different semantics from the libc functions. The libc functions follow POSIX and update the credentials for all threads in the process; the system calls update only the thread which makes the call. (This impedance mismatch is worked around in libc by signalling all threads to tell them to do a syscall, in a byzantine and fragile way; see http://ewontfix.com/17/.) Since in linux-user we are trying to emulate the system call semantics, we must implement all these syscalls to directly call the underlying host syscall, rather than calling the host libc function. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
2016-05-27linux-user: x86_64: Don't use 16-bit UIDsPeter Maydell
The 64-bit x86 syscall ABI uses 32-bit UIDs; only define USE_UID16 for 32-bit x86. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
2016-05-27linux-user: Use g_try_malloc() in do_msgrcv()Peter Maydell
In do_msgrcv() we want to allocate a message buffer, whose size is passed to us by the guest. That means we could legitimately fail, so use g_try_malloc() and handle the error case, in the same way that do_msgsnd() does. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
2016-05-27linux-user: Handle msgrcv error case correctlyPeter Maydell
The msgrcv ABI is a bit odd -- the msgsz argument is a size_t, which is unsigned, but it must fail EINVAL if the value is negative when cast to a long. We were incorrectly passing the value through an "unsigned int", which meant that if the guest was 32-bit longs and the host was 64-bit longs an input of 0xffffffff (which should trigger EINVAL) would simply be passed to the host msgrcv() as 0xffffffff, where it does not cause the host kernel to reject it. Follow the same approach as do_msgsnd() in using a ssize_t and doing the check for negative values by hand, so we correctly fail in this corner case. This fixes the msgrcv03 Linux Test Project test case, which otherwise hangs. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
2016-05-27linux-user: Handle negative values in timespec conversionPeter Maydell
In a struct timespec, both fields are signed longs. Converting them from guest to host with code like host_ts->tv_sec = tswapal(target_ts->tv_sec); mishandles negative values if the guest has 32-bit longs and the host has 64-bit longs because tswapal()'s return type is abi_ulong: the assignment will zero-extend into the host long type rather than sign-extending it. Make the conversion routines use __get_user() and __set_user() instead: this automatically picks up the signedness of the field type and does the correct kind of sign or zero extension. It also handles the possibility that the target struct is not sufficiently aligned for the host's requirements. In particular, this fixes a hang when running the Linux Test Project mq_timedsend01 and mq_timedreceive01 tests: one of the test cases sets the timeout to -1 and expects an EINVAL failure, but we were setting a very long timeout instead. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
2016-05-27linux-user: Use safe_syscall for futex syscallPeter Maydell
Use the safe_syscall wrapper for the futex syscall. In particular, this fixes hangs when using programs that link against the Boehm garbage collector, including the Mono runtime. (We don't change the sys_futex() call in the implementation of the exit syscall, because as the FIXME comment there notes that should be handled by disabling signals, since we can't easily back out if the futex were to return ERESTARTSYS.) Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
2016-05-27linux-user: Use safe_syscall for pselect, select syscallsPeter Maydell
Use the safe_syscall wrapper for the pselect and select syscalls. Since not every architecture has the select syscall, we now have to implement select in terms of pselect, which means doing timeval<->timespec conversion. (Five years on from the initial patch that added pselect support to QEMU and a decade after pselect6 went into the kernel, it seems safe to not try to support hosts with header files which don't define __NR_pselect6.) Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
2016-05-27linux-user: Use safe_syscall for execve syscallTimothy E Baldwin
Wrap execve() in the safe-syscall handling. Although execve() is not an interruptible syscall, it is a special case: if we allow a signal to happen before we make the host$ syscall then we will 'lose' it, because at the point of execve the process leaves QEMU's control. So we use the safe syscall wrapper to ensure that we either take the signal as a guest signal, or else it does not happen before the execve completes and makes it the other program's problem. The practical upshot is that without this SIGTERM could fail to terminate the process. Signed-off-by: Timothy Edward Baldwin <T.E.Baldwin99@members.leeds.ac.uk> Message-id: 1441497448-32489-25-git-send-email-T.E.Baldwin99@members.leeds.ac.uk [PMM: expanded commit message to explain in more detail why this is needed, and add comment about it too] 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>
2016-05-27linux-user: Use safe_syscall for wait system callsTimothy E Baldwin
Use safe_syscall for waitpid, waitid and wait4 syscalls. Note that this change allows us to implement support for waitid's fifth (rusage) argument in future; for the moment we ignore it as we have done up til now. Signed-off-by: Timothy Edward Baldwin <T.E.Baldwin99@members.leeds.ac.uk> Message-id: 1441497448-32489-18-git-send-email-T.E.Baldwin99@members.leeds.ac.uk [PMM: Adjust to new safe_syscall convention. Add fifth waitid syscall argument (which isn't present in the libc interface but is in the syscall ABI)] Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
2016-05-27linux-user: Use safe_syscall for open and openat system callsTimothy E Baldwin
Restart open() and openat() if signals occur before, or during with SA_RESTART. Signed-off-by: Timothy Edward Baldwin <T.E.Baldwin99@members.leeds.ac.uk> Message-id: 1441497448-32489-17-git-send-email-T.E.Baldwin99@members.leeds.ac.uk [PMM: Adjusted to follow new -1-and-set-errno safe_syscall convention] Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
2016-05-27linux-user: Use safe_syscall for read and write system callsTimothy E Baldwin
Restart read() and write() if signals occur before, or during with SA_RESTART Signed-off-by: Timothy Edward Baldwin <T.E.Baldwin99@members.leeds.ac.uk> Message-id: 1441497448-32489-15-git-send-email-T.E.Baldwin99@members.leeds.ac.uk [PMM: Update to new safe_syscall() convention of setting errno] 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>
2016-05-27linux-user: Provide safe_syscall for fixing races between signals and syscallsTimothy E Baldwin
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>
2016-05-27linux-user: Add debug code to exercise restarting system callsTimothy E Baldwin
If DEBUG_ERESTARTSYS is set restart all system calls once. This is pure debug code for exercising the syscall restart code paths in the per-architecture cpu main loops. Signed-off-by: Timothy Edward Baldwin <T.E.Baldwin99@members.leeds.ac.uk> Message-id: 1441497448-32489-10-git-send-email-T.E.Baldwin99@members.leeds.ac.uk [PMM: Add comment and a commented-out #define next to the commented-out generic DEBUG #define; remove the check on TARGET_USE_ERESTARTSYS; tweak comment 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>
2016-05-27linux-user: Support for restarting system calls for Microblaze targetsTimothy E Baldwin
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>
2016-05-27linux-user: Set r14 on exit from microblaze syscallPeter Maydell
All syscall exits on microblaze result in r14 being equal to the PC we return to, because the kernel syscall exit instruction "rtbd" does this. (This is true even for sigreturn(); note that r14 is not a userspace-usable register as the kernel may clobber it at any point.) Emulate the setting of r14 on exit; this isn't really a guest visible change for valid guest code because r14 isn't reliably observable anyway. However having the code and the comment helps to explain why it's ok for the ERESTARTSYS handling not to undo the changes to r14 that happen on syscall entry. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
2016-05-27linux-user: Support for restarting system calls for tilegx targetsPeter Maydell
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>
2016-05-27linux-user: Support for restarting system calls for CRIS targetsTimothy E Baldwin
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>
2016-05-27linux-user: Support for restarting system calls for S390 targetsTimothy E Baldwin
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>
2016-05-27linux-user: Support for restarting system calls for M68K targetsTimothy E Baldwin
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>
2016-05-27linux-user: Support for restarting system calls for OpenRISC targetsTimothy E Baldwin
Update the OpenRISC main loop 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 (We don't implement sigreturn on this target so there is no code there to update.) Signed-off-by: Timothy Edward Baldwin <T.E.Baldwin99@members.leeds.ac.uk> Message-id: 1441497448-32489-31-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>
2016-05-27linux-user: Support for restarting system calls for UniCore32 targetsTimothy E Baldwin
Update the UniCore32 main loop 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 (We don't support signals on this target so there is no sigreturn code to update.) Signed-off-by: Timothy Edward Baldwin <T.E.Baldwin99@members.leeds.ac.uk> Message-id: 1441497448-32489-30-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>
2016-05-27linux-user: Support for restarting system calls for Alpha targetsTimothy E Baldwin
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>
2016-05-27linux-user: Support for restarting system calls for SH4 targetsTimothy E Baldwin
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>
2016-05-27linux-user: Support for restarting system calls for SPARC targetsTimothy E Baldwin
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>
2016-05-27linux-user: Support for restarting system calls for PPC targetsTimothy E Baldwin
Update the PPC main loop code: * on TARGET_ERESTARTSYS, wind guest PC backwards to repeat syscall insn (We already handle TARGET_QEMU_ESIGRETURN.) Signed-off-by: Timothy Edward Baldwin <T.E.Baldwin99@members.leeds.ac.uk> Message-id: 1441497448-32489-8-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>
2016-05-27linux-user: Support for restarting system calls for MIPS targetsTimothy E Baldwin
Update the MIPS main loop code: * on TARGET_ERESTARTSYS, wind guest PC backwards to repeat syscall insn (We already handle TARGET_QEMU_ESIGRETURN.) Signed-off-by: Timothy Edward Baldwin <T.E.Baldwin99@members.leeds.ac.uk> Message-id: 1441497448-32489-7-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>
2016-05-27linux-user: Support for restarting system calls for ARM targetsTimothy E Baldwin
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>
2016-05-27linux-user: Support for restarting system calls for x86 targetsTimothy E Baldwin
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>
2016-05-27linux-user: Renumber TARGET_QEMU_ESIGRETURN, make it not arch-specificTimothy E Baldwin
Currently we define a QEMU-internal errno TARGET_QEMU_ESIGRETURN only on the MIPS and PPC targets; move this to errno_defs.h so it is available for all architectures, and renumber it to 513. We pick 513 because this is safe from future use as a system call return value: Linux uses it as ERESTART_NOINTR internally and never allows that errno to escape to userspace. Signed-off-by: Timothy Edward Baldwin <T.E.Baldwin99@members.leeds.ac.uk> Message-id: 1441497448-32489-4-git-send-email-T.E.Baldwin99@members.leeds.ac.uk [PMM: TARGET_ERESTARTSYS split out into preceding patch, add comment] Reviewed-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Laurent Vivier <laurent@vivier.eu> Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
2016-05-27linux-user: Define TARGET_ERESTART* errno valuesTimothy E Baldwin
Define TARGET_ERESTARTSYS; like the kernel, we will use this to indicate that a guest system call should be restarted. We use the same value the kernel does for this, 512. Signed-off-by: Timothy Edward Baldwin <T.E.Baldwin99@members.leeds.ac.uk> [PMM: split out from the patch which moves and renumbers TARGET_QEMU_ESIGRETURN, add comment on usage] 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>