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2016-06-26linux-user: Don't use sigfillset() on uc->uc_sigmaskPeter Maydell
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>
2016-06-24linux-user: Avoid possible misalignment in host_to_target_siginfo()Peter Maydell
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>
2016-06-20coccinelle: Remove unnecessary variables for function return valueEduardo Habkost
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>
2016-06-08linux-user: Avoid possible misalignment in target_to_host_siginfo()Peter Maydell
Reimplement target_to_host_siginfo() to use __get_user(), which handles possibly misaligned source guest structures correctly. 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>
2016-06-07linux-user: Use both si_code and si_signo when converting siginfo_tPeter Maydell
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>
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: 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>
2016-05-27linux-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: 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: 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: 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 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 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: Reindent signal handlingTimothy E Baldwin
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>
2016-03-04linux-user: arm: fix coding style for some linux-user signal functionsPaolo Bonzini
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>
2016-02-26linux-user: Use restrictive mask when calling cpsr_write()Peter Maydell
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
2016-02-26target-arm: Add write_type argument to cpsr_write()Peter Maydell
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
2016-01-29linux-user: Clean up includesPeter Maydell
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
2016-01-08linux-user,sh4: fix signal retcode addressLaurent Vivier
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>
2015-12-17linux-user: convert DEBUG_SIGNAL logging to tracepointsPaolo Bonzini
"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>
2015-10-07linux-user/tilegx: Implement tilegx signal featuresChen Gang
[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>
2015-10-01linux-user/signal.c: Use setup_rt_frame() instead of setup_frame() for ↵Chen Gang
target openrisc 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>
2015-09-11maint: remove unused include for assert.hDaniel P. Berrange
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>
2015-07-09translate-all: Change tb_flush() env argument to cpuPeter Crosthwaite
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>
2015-05-27s390x: Common access to floating point registersEric Farman
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>
2015-01-27linux-user: Fix broken m68k signal handling on 64 bit hostsPeter Maydell
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>
2015-01-27linux-user/signal.c: Remove unnecessary wrapper copy_siginfo_to_userPeter Maydell
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>
2015-01-27linux-user/signal.c: Remove current_exec_domain_sig()Peter Maydell
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>
2014-09-08linux-user: Handle PPC64 ELFv2 Function PointersTom Musta
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>
2014-09-08linux-user: Implement do_setcontext for PPC64Tom Musta
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>
2014-09-08linux-user: Properly Dereference PPC64 ELFv1 Signal Handler PointerTom Musta
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>
2014-09-08linux-user: Enable Signal Handlers on PPC64Tom Musta
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>
2014-09-08linux-user: Split PPC Trampoline Encoding from Register SaveTom Musta
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>
2014-09-08linux-user: Fix Stack Pointer Bug in PPC setup_rt_frameTom Musta
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 beb526b12134a6b6744125deec5a7fe24a8f92e3 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>