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path: root/linux-user/syscall.c
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2016-06-16os-posix: include sys/mman.hPaolo Bonzini
qemu/osdep.h checks whether MAP_ANONYMOUS is defined, but this check is bogus without a previous inclusion of sys/mman.h. Include it in sysemu/os-posix.h and remove it from everywhere else. Reviewed-by: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-06-08Merge remote-tracking branch 'remotes/riku/tags/pull-linux-user-20160608' ↵Peter Maydell
into staging linux-user pull request for June 2016 # gpg: Signature made Wed 08 Jun 2016 14:27:14 BST # gpg: using RSA key 0xB44890DEDE3C9BC0 # gpg: Good signature from "Riku Voipio <riku.voipio@iki.fi>" # gpg: aka "Riku Voipio <riku.voipio@linaro.org>" * remotes/riku/tags/pull-linux-user-20160608: (44 commits) linux-user: In fork_end(), remove correct CPUs from CPU list linux-user: Special-case ERESTARTSYS in target_strerror() linux-user: Make target_strerror() return 'const char *' linux-user: Correct signedness of target_flock l_start and l_len fields linux-user: Use safe_syscall wrapper for ioctl linux-user: Use safe_syscall wrapper for accept and accept4 syscalls linux-user: Use safe_syscall wrapper for semop linux-user: Use safe_syscall wrapper for epoll_wait syscalls linux-user: Use safe_syscall wrapper for poll and ppoll syscalls linux-user: Use safe_syscall wrapper for sleep syscalls linux-user: Use safe_syscall wrapper for rt_sigtimedwait syscall linux-user: Use safe_syscall wrapper for flock linux-user: Use safe_syscall wrapper for mq_timedsend and mq_timedreceive linux-user: Use safe_syscall wrapper for msgsnd and msgrcv linux-user: Use safe_syscall wrapper for send* and recv* syscalls linux-user: Use safe_syscall wrapper for connect syscall linux-user: Use safe_syscall wrapper for readv and writev syscalls linux-user: Fix error conversion in 64-bit fadvise syscall linux-user: Fix NR_fadvise64 and NR_fadvise64_64 for 32-bit guests linux-user: Fix handling of arm_fadvise64_64 syscall ... Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Conflicts: configure scripts/qemu-binfmt-conf.sh
2016-06-08linux-user: Special-case ERESTARTSYS in target_strerror()Peter Maydell
Since TARGET_ERESTARTSYS and TARGET_ESIGRETURN are internal-to-QEMU error numbers, handle them specially in target_strerror(), to avoid confusing strace output like: 9521 rt_sigreturn(14,8,274886297808,8,0,268435456) = -1 errno=513 (Unknown error 513) Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
2016-06-08linux-user: Make target_strerror() return 'const char *'Peter Maydell
Make target_strerror() return 'const char *' rather than just 'char *'; this will allow us to return constant strings from it for some special cases. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: Riku Voipio <riku.voipio@linaro.org> Reviewed-by: Laurent Vivier <laurent@vivier.eu>
2016-06-08linux-user: Use safe_syscall wrapper for ioctlPeter Maydell
Use the safe_syscall wrapper to implement the ioctl syscall. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
2016-06-08linux-user: Use safe_syscall wrapper for accept and accept4 syscallsPeter Maydell
Use the safe_syscall wrapper for the accept and accept4 syscalls. accept4 has been in the kernel since 2.6.28 so we can assume it is always present. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
2016-06-08linux-user: Use safe_syscall wrapper for semopPeter Maydell
Use the safe_syscall wrapper for the semop syscall or IPC operation. (We implement via the semtimedop syscall to make it easier to implement the guest semtimedop syscall later.) Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
2016-06-08linux-user: Use safe_syscall wrapper for epoll_wait syscallsPeter Maydell
Use the safe_syscall wrapper for epoll_wait and epoll_pwait syscalls. Since we now directly use the host epoll_pwait syscall for both epoll_wait and epoll_pwait, we don't need the configure machinery to check whether glibc supports epoll_pwait(). (The kernel has supported the syscall since 2.6.19 so we can assume it's always there.) Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
2016-06-08linux-user: Use safe_syscall wrapper for poll and ppoll syscallsPeter Maydell
Use the safe_syscall wrapper for the poll and ppoll syscalls. Since not all host architectures will have a poll syscall, we have to rewrite the TARGET_NR_poll handling to use ppoll instead (we can assume everywhere has ppoll by now). We take the opportunity to switch to the code structure already used in the implementation of epoll_wait and epoll_pwait, which uses a switch() to avoid interleaving #if and if (), and to stop using a variable with a leading '_' which is in the implementation's namespace. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
2016-06-08linux-user: Use safe_syscall wrapper for sleep syscallsPeter Maydell
Use the safe_syscall wrapper for the clock_nanosleep and nanosleep syscalls. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
2016-06-08linux-user: Use safe_syscall wrapper for rt_sigtimedwait syscallPeter Maydell
Use the safe_syscall wrapper for the rt_sigtimedwait syscall. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
2016-06-08linux-user: Use safe_syscall wrapper for flockPeter Maydell
Use the safe_syscall wrapper for the flock syscall. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
2016-06-08linux-user: Use safe_syscall wrapper for mq_timedsend and mq_timedreceivePeter Maydell
Use the safe_syscall wrapper for mq_timedsend and mq_timedreceive syscalls. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
2016-06-08linux-user: Use safe_syscall wrapper for msgsnd and msgrcvPeter Maydell
Use the safe_syscall wrapper for msgsnd and msgrcv syscalls. This is made slightly awkward by some host architectures providing only a single 'ipc' syscall rather than separate syscalls per operation; we provide safe_msgsnd() and safe_msgrcv() as wrappers around safe_ipc() to handle this if needed. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
2016-06-08linux-user: Use safe_syscall wrapper for send* and recv* syscallsPeter Maydell
Use the safe_syscall wrapper for the send, sendto, sendmsg, recv, recvfrom and recvmsg syscalls. RV: adjusted to apply Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
2016-06-08linux-user: Use safe_syscall wrapper for connect syscallPeter Maydell
Use the safe_syscall wrapper for the connect syscall. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
2016-06-08linux-user: Use safe_syscall wrapper for readv and writev syscallsPeter Maydell
Use the safe_syscall wrapper for readv and writev syscalls. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
2016-06-08linux-user: Fix error conversion in 64-bit fadvise syscallPeter Maydell
Fix a missing host-to-target errno conversion in the 64-bit fadvise syscall emulation. 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>
2016-06-08linux-user: Fix NR_fadvise64 and NR_fadvise64_64 for 32-bit guestsPeter Maydell
Fix errors in the implementation of NR_fadvise64 and NR_fadvise64_64 for 32-bit guests, which pass their off_t values in register pairs. We can't use the 64-bit code path for this, so split out the 32-bit cases, so that we can correctly handle the "only offset is 64-bit" and "both offset and length are 64-bit" syscall flavours, and "uses aligned register pairs" and "does not" flavours of target. 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>
2016-06-08linux-user: Fix handling of arm_fadvise64_64 syscallPeter Maydell
32-bit ARM has an odd variant of the fadvise syscall which has rearranged arguments, which we try to implement. Unfortunately we got the rearrangement wrong. This is a six-argument syscall whose arguments are: * fd * advise parameter * offset high half * offset low half * len high half * len low half Stop trying to share code with the standard fadvise syscalls, and just implement the syscall with the correct argument order. 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: Use DIV_ROUND_UPLaurent Vivier
Replace (((n) + (d) - 1) /(d)) by DIV_ROUND_UP(n,d). This patch is the result of coccinelle script scripts/coccinelle/round.cocci CC: Riku Voipio <riku.voipio@iki.fi> Signed-off-by: Laurent Vivier <lvivier@redhat.com> Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
2016-06-07linux-user: Restart fork() if signals pendingTimothy E Baldwin
If there is a signal pending during fork() the signal handler will erroneously be called in both the parent and child, so handle any pending signals first. Signed-off-by: Timothy Edward Baldwin <T.E.Baldwin99@members.leeds.ac.uk> Message-id: 1441497448-32489-20-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: Use safe_syscall for kill, tkill and tgkill syscallsPeter Maydell
Use the safe_syscall wrapper for the kill, tkill and tgkill syscalls. Without this, if a thread sent a SIGKILL to itself it could kill the thread before we had a chance to process a signal that arrived just before the SIGKILL, and that signal would get lost. We drop all the ifdeffery for tkill and tgkill, because every guest architecture we support implements them, and they've been in Linux since 2003 so we can assume the host headers define the __NR_tkill and __NR_tgkill constants. 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: Restart exit() if signal pendingTimothy E Baldwin
Without this a signal could vanish on thread exit. Signed-off-by: Timothy Edward Baldwin <T.E.Baldwin99@members.leeds.ac.uk> Message-id: 1441497448-32489-26-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: pause() should not pause if signal pendingTimothy E Baldwin
Fix races between signal handling and the pause syscall by reimplementing it using block_signals() and sigsuspend(). (Using safe_syscall(pause) would also work, except that the pause syscall doesn't exist on all architectures.) Signed-off-by: Timothy Edward Baldwin <T.E.Baldwin99@members.leeds.ac.uk> Message-id: 1441497448-32489-28-git-send-email-T.E.Baldwin99@members.leeds.ac.uk [PMM: tweaked 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: 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: 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: 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: 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 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: Consistently return host errnos from do_openat()Peter Maydell
The function do_openat() is not consistent about whether it is returning a host errno or a guest errno in case of failure. Standardise on returning -1 with errno set (ie caller has to call get_errno()). Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reported-by: Timothy Edward Baldwin <T.E.Baldwin99@members.leeds.ac.uk> Signed-off-by: Riku Voipio <riku.voipio@linaro.org> Reviewed-by: Laurent Vivier <laurent@vivier.eu>
2016-05-27linux-user: Check array bounds in errno conversionTimothy E Baldwin
Check array bounds in host_to_target_errno() and target_to_host_errno(). Signed-off-by: Timothy Edward Baldwin <T.E.Baldwin99@members.leeds.ac.uk> Message-id: 1441497448-32489-2-git-send-email-T.E.Baldwin99@members.leeds.ac.uk [PMM: Add a lower-bound check, use braces on if(), tweak commit message] Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: Riku Voipio <riku.voipio@linaro.org> Reviewed-by: Laurent Vivier <laurent@vivier.eu>
2016-03-22util: move declarations out of qemu-common.hVeronia Bahaa
Move declarations out of qemu-common.h for functions declared in utils/ files: e.g. include/qemu/path.h for utils/path.c. Move inline functions out of qemu-common.h and into new files (e.g. include/qemu/bcd.h) Signed-off-by: Veronia Bahaa <veroniabahaa@gmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-02-24linux-user: add getrandom() syscallLaurent Vivier
getrandom() has been introduced in kernel 3.17 and is now used during the boot sequence of Debian unstable (stretch/sid). Signed-off-by: Laurent Vivier <laurent@vivier.eu> Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
2016-02-23linux-user: remove unavailable syscalls from aarch64Riku Voipio
QEMU lists deprecated system call numbers in for Aarch64. These are never enabled for Linux kernel, so don't define them in Qemu either. Remove the ifdef around host_to_target_stat64 since all architectures need it now. Reviewed-by: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: Riku Voipio <riku.voipio@linaro.org>