diff --git a/Makefile.target b/Makefile.target
index 34ddb7e..c83d7ef 100644
--- a/Makefile.target
+++ b/Makefile.target
@@ -108,7 +108,9 @@ obj-$(CONFIG_LIBDECNUMBER) += libdecnumber/dpd/decimal128.o
 
 ifdef CONFIG_LINUX_USER
 
-QEMU_CFLAGS+=-I$(SRC_PATH)/linux-user/$(TARGET_ABI_DIR) -I$(SRC_PATH)/linux-user
+QEMU_CFLAGS+=-I$(SRC_PATH)/linux-user/$(TARGET_ABI_DIR) \
+             -I$(SRC_PATH)/linux-user/host/$(ARCH) \
+             -I$(SRC_PATH)/linux-user
 
 obj-y += linux-user/
 obj-y += gdbstub.o thunk.o user-exec.o
diff --git a/linux-user/Makefile.objs b/linux-user/Makefile.objs
index fd50217..8c93058 100644
--- a/linux-user/Makefile.objs
+++ b/linux-user/Makefile.objs
@@ -1,5 +1,6 @@
 obj-y = main.o syscall.o strace.o mmap.o signal.o \
-	elfload.o linuxload.o uaccess.o uname.o
+	elfload.o linuxload.o uaccess.o uname.o \
+	safe-syscall.o
 
 obj-$(TARGET_HAS_BFLT) += flatload.o
 obj-$(TARGET_I386) += vm86.o
diff --git a/linux-user/host/x86_64/hostdep.h b/linux-user/host/x86_64/hostdep.h
new file mode 100644
index 0000000..9dfbf3a
--- /dev/null
+++ b/linux-user/host/x86_64/hostdep.h
@@ -0,0 +1,38 @@
+/*
+ * hostdep.h : things which are dependent on the host architecture
+ *
+ *  * Written by Peter Maydell <peter.maydell@linaro.org>
+ *
+ * Copyright (C) 2016 Linaro Limited
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ */
+
+#ifndef QEMU_HOSTDEP_H
+#define QEMU_HOSTDEP_H
+
+/* We have a safe-syscall.inc.S */
+#define HAVE_SAFE_SYSCALL
+
+#ifndef __ASSEMBLER__
+
+/* These are defined by the safe-syscall.inc.S file */
+extern char safe_syscall_start[];
+extern char safe_syscall_end[];
+
+/* Adjust the signal context to rewind out of safe-syscall if we're in it */
+static inline void rewind_if_in_safe_syscall(void *puc)
+{
+    struct ucontext *uc = puc;
+    greg_t *pcreg = &uc->uc_mcontext.gregs[REG_RIP];
+
+    if (*pcreg > (uintptr_t)safe_syscall_start
+        && *pcreg < (uintptr_t)safe_syscall_end) {
+        *pcreg = (uintptr_t)safe_syscall_start;
+    }
+}
+
+#endif /* __ASSEMBLER__ */
+
+#endif
diff --git a/linux-user/host/x86_64/safe-syscall.inc.S b/linux-user/host/x86_64/safe-syscall.inc.S
new file mode 100644
index 0000000..dde434c
--- /dev/null
+++ b/linux-user/host/x86_64/safe-syscall.inc.S
@@ -0,0 +1,81 @@
+/*
+ * safe-syscall.inc.S : host-specific assembly fragment
+ * to handle signals occurring at the same time as system calls.
+ * This is intended to be included by linux-user/safe-syscall.S
+ *
+ * Copyright (C) 2015 Timothy Edward Baldwin <T.E.Baldwin99@members.leeds.ac.uk>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ */
+
+        .global safe_syscall_base
+        .global safe_syscall_start
+        .global safe_syscall_end
+        .type   safe_syscall_base, @function
+
+        /* This is the entry point for making a system call. The calling
+         * convention here is that of a C varargs function with the
+         * first argument an 'int *' to the signal_pending flag, the
+         * second one the system call number (as a 'long'), and all further
+         * arguments being syscall arguments (also 'long').
+         * We return a long which is the syscall's return value, which
+         * may be negative-errno on failure. Conversion to the
+         * -1-and-errno-set convention is done by the calling wrapper.
+         */
+safe_syscall_base:
+        /* This saves a frame pointer and aligns the stack for the syscall.
+         * (It's unclear if the syscall ABI has the same stack alignment
+         * requirements as the userspace function call ABI, but better safe than
+         * sorry. Appendix A2 of http://www.x86-64.org/documentation/abi.pdf
+         * does not list any ABI differences regarding stack alignment.)
+         */
+        push    %rbp
+
+        /* The syscall calling convention isn't the same as the
+         * C one:
+         * we enter with rdi == *signal_pending
+         *               rsi == syscall number
+         *               rdx, rcx, r8, r9, (stack), (stack) == syscall arguments
+         *               and return the result in rax
+         * and the syscall instruction needs
+         *               rax == syscall number
+         *               rdi, rsi, rdx, r10, r8, r9 == syscall arguments
+         *               and returns the result in rax
+         * Shuffle everything around appropriately.
+         * Note that syscall will trash rcx and r11.
+         */
+        mov     %rsi, %rax /* syscall number */
+        mov     %rdi, %rbp /* signal_pending pointer */
+        /* and the syscall arguments */
+        mov     %rdx, %rdi
+        mov     %rcx, %rsi
+        mov     %r8,  %rdx
+        mov     %r9,  %r10
+        mov     16(%rsp), %r8
+        mov     24(%rsp), %r9
+
+        /* This next sequence of code works in conjunction with the
+         * rewind_if_safe_syscall_function(). If a signal is taken
+         * and the interrupted PC is anywhere between 'safe_syscall_start'
+         * and 'safe_syscall_end' then we rewind it to 'safe_syscall_start'.
+         * The code sequence must therefore be able to cope with this, and
+         * the syscall instruction must be the final one in the sequence.
+         */
+safe_syscall_start:
+        /* if signal_pending is non-zero, don't do the call */
+        testl   $1, (%rbp)
+        jnz     return_ERESTARTSYS
+        syscall
+safe_syscall_end:
+        /* code path for having successfully executed the syscall */
+        pop     %rbp
+        ret
+
+return_ERESTARTSYS:
+        /* code path when we didn't execute the syscall */
+        mov     $-TARGET_ERESTARTSYS, %rax
+        pop     %rbp
+        ret
+
+        .size   safe_syscall_base, .-safe_syscall_base
diff --git a/linux-user/qemu.h b/linux-user/qemu.h
index 26b0ba2..5126b7b 100644
--- a/linux-user/qemu.h
+++ b/linux-user/qemu.h
@@ -1,7 +1,7 @@
 #ifndef QEMU_H
 #define QEMU_H
 
-
+#include "hostdep.h"
 #include "cpu.h"
 #include "exec/cpu_ldst.h"
 
@@ -204,6 +204,131 @@ unsigned long init_guest_space(unsigned long host_start,
 
 #include "qemu/log.h"
 
+/* safe_syscall.S */
+
+/**
+ * safe_syscall:
+ * @int number: number of system call to make
+ * ...: arguments to the system call
+ *
+ * Call a system call if guest signal not pending.
+ * This has the same API as the libc syscall() function, except that it
+ * may return -1 with errno == TARGET_ERESTARTSYS if a signal was pending.
+ *
+ * Returns: the system call result, or -1 with an error code in errno
+ * (Errnos are host errnos; we rely on TARGET_ERESTARTSYS not clashing
+ * with any of the host errno values.)
+ */
+
+/* A guide to using safe_syscall() to handle interactions between guest
+ * syscalls and guest signals:
+ *
+ * Guest syscalls come in two flavours:
+ *
+ * (1) Non-interruptible syscalls
+ *
+ * These are guest syscalls that never get interrupted by signals and
+ * so never return EINTR. They can be implemented straightforwardly in
+ * QEMU: just make sure that if the implementation code has to make any
+ * blocking calls that those calls are retried if they return EINTR.
+ * It's also OK to implement these with safe_syscall, though it will be
+ * a little less efficient if a signal is delivered at the 'wrong' moment.
+ *
+ * (2) Interruptible syscalls
+ *
+ * These are guest syscalls that can be interrupted by signals and
+ * for which we need to either return EINTR or arrange for the guest
+ * syscall to be restarted. This category includes both syscalls which
+ * always restart (and in the kernel return -ERESTARTNOINTR), ones
+ * which only restart if there is no handler (kernel returns -ERESTARTNOHAND
+ * or -ERESTART_RESTARTBLOCK), and the most common kind which restart
+ * if the handler was registered with SA_RESTART (kernel returns
+ * -ERESTARTSYS). System calls which are only interruptible in some
+ * situations (like 'open') also need to be handled this way.
+ *
+ * Here it is important that the host syscall is made
+ * via this safe_syscall() function, and *not* via the host libc.
+ * If the host libc is used then the implementation will appear to work
+ * most of the time, but there will be a race condition where a
+ * signal could arrive just before we make the host syscall inside libc,
+ * and then then guest syscall will not correctly be interrupted.
+ * Instead the implementation of the guest syscall can use the safe_syscall
+ * function but otherwise just return the result or errno in the usual
+ * way; the main loop code will take care of restarting the syscall
+ * if appropriate.
+ *
+ * (If the implementation needs to make multiple host syscalls this is
+ * OK; any which might really block must be via safe_syscall(); for those
+ * which are only technically blocking (ie which we know in practice won't
+ * stay in the host kernel indefinitely) it's OK to use libc if necessary.
+ * You must be able to cope with backing out correctly if some safe_syscall
+ * you make in the implementation returns either -TARGET_ERESTARTSYS or
+ * EINTR though.)
+ *
+ *
+ * How and why the safe_syscall implementation works:
+ *
+ * The basic setup is that we make the host syscall via a known
+ * section of host native assembly. If a signal occurs, our signal
+ * handler checks the interrupted host PC against the addresse of that
+ * known section. If the PC is before or at the address of the syscall
+ * instruction then we change the PC to point at a "return
+ * -TARGET_ERESTARTSYS" code path instead, and then exit the signal handler
+ * (causing the safe_syscall() call to immediately return that value).
+ * Then in the main.c loop if we see this magic return value we adjust
+ * the guest PC to wind it back to before the system call, and invoke
+ * the guest signal handler as usual.
+ *
+ * This winding-back will happen in two cases:
+ * (1) signal came in just before we took the host syscall (a race);
+ *   in this case we'll take the guest signal and have another go
+ *   at the syscall afterwards, and this is indistinguishable for the
+ *   guest from the timing having been different such that the guest
+ *   signal really did win the race
+ * (2) signal came in while the host syscall was blocking, and the
+ *   host kernel decided the syscall should be restarted;
+ *   in this case we want to restart the guest syscall also, and so
+ *   rewinding is the right thing. (Note that "restart" semantics mean
+ *   "first call the signal handler, then reattempt the syscall".)
+ * The other situation to consider is when a signal came in while the
+ * host syscall was blocking, and the host kernel decided that the syscall
+ * should not be restarted; in this case QEMU's host signal handler will
+ * be invoked with the PC pointing just after the syscall instruction,
+ * with registers indicating an EINTR return; the special code in the
+ * handler will not kick in, and we will return EINTR to the guest as
+ * we should.
+ *
+ * Notice that we can leave the host kernel to make the decision for
+ * us about whether to do a restart of the syscall or not; we do not
+ * need to check SA_RESTART flags in QEMU or distinguish the various
+ * kinds of restartability.
+ */
+#ifdef HAVE_SAFE_SYSCALL
+/* The core part of this function is implemented in assembly */
+extern long safe_syscall_base(int *pending, long number, ...);
+
+#define safe_syscall(...)                                               \
+    ({                                                                  \
+        long ret_;                                                      \
+        int *psp_ = &((TaskState *)thread_cpu->opaque)->signal_pending; \
+        ret_ = safe_syscall_base(psp_, __VA_ARGS__);                    \
+        if (is_error(ret_)) {                                           \
+            errno = -ret_;                                              \
+            ret_ = -1;                                                  \
+        }                                                               \
+        ret_;                                                           \
+    })
+
+#else
+
+/* Fallback for architectures which don't yet provide a safe-syscall assembly
+ * fragment; note that this is racy!
+ * This should go away when all host architectures have been updated.
+ */
+#define safe_syscall syscall
+
+#endif
+
 /* syscall.c */
 int host_to_target_waitstatus(int status);
 
diff --git a/linux-user/safe-syscall.S b/linux-user/safe-syscall.S
new file mode 100644
index 0000000..b5df625
--- /dev/null
+++ b/linux-user/safe-syscall.S
@@ -0,0 +1,30 @@
+/*
+ * safe-syscall.S : include the host-specific assembly fragment
+ * to handle signals occurring at the same time as system calls.
+ *
+ * Written by Peter Maydell <peter.maydell@linaro.org>
+ *
+ * Copyright (C) 2016 Linaro Limited
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ */
+
+#include "hostdep.h"
+#include "errno_defs.h"
+
+/* We have the correct host directory on our include path
+ * so that this will pull in the right fragment for the architecture.
+ */
+#ifdef HAVE_SAFE_SYSCALL
+#include "safe-syscall.inc.S"
+#endif
+
+/* We must specifically say that we're happy for the stack to not be
+ * executable, otherwise the toolchain will default to assuming our
+ * assembly needs an executable stack and the whole QEMU binary will
+ * needlessly end up with one. This should be the last thing in this file.
+ */
+#if defined(__linux__) && defined(__ELF__)
+.section        .note.GNU-stack, "", %progbits
+#endif
diff --git a/linux-user/signal.c b/linux-user/signal.c
index 9e85550..ff4de4f 100644
--- a/linux-user/signal.c
+++ b/linux-user/signal.c
@@ -561,6 +561,13 @@ int queue_signal(CPUArchState *env, int sig, target_siginfo_t *info)
     }
 }
 
+#ifndef HAVE_SAFE_SYSCALL
+static inline void rewind_if_in_safe_syscall(void *puc)
+{
+    /* Default version: never rewind */
+}
+#endif
+
 static void host_signal_handler(int host_signum, siginfo_t *info,
                                 void *puc)
 {
@@ -581,6 +588,9 @@ static void host_signal_handler(int host_signum, siginfo_t *info,
     if (sig < 1 || sig > TARGET_NSIG)
         return;
     trace_user_host_signal(env, host_signum, sig);
+
+    rewind_if_in_safe_syscall(puc);
+
     host_to_target_siginfo_noswap(&tinfo, info);
     if (queue_signal(env, sig, &tinfo) == 1) {
         /* interrupt the virtual CPU as soon as possible */
diff --git a/linux-user/syscall.c b/linux-user/syscall.c
index ced519d..b6a8ed6 100644
--- a/linux-user/syscall.c
+++ b/linux-user/syscall.c
@@ -660,6 +660,53 @@ char *target_strerror(int err)
     return strerror(target_to_host_errno(err));
 }
 
+#define safe_syscall0(type, name) \
+static type safe_##name(void) \
+{ \
+    return safe_syscall(__NR_##name); \
+}
+
+#define safe_syscall1(type, name, type1, arg1) \
+static type safe_##name(type1 arg1) \
+{ \
+    return safe_syscall(__NR_##name, arg1); \
+}
+
+#define safe_syscall2(type, name, type1, arg1, type2, arg2) \
+static type safe_##name(type1 arg1, type2 arg2) \
+{ \
+    return safe_syscall(__NR_##name, arg1, arg2); \
+}
+
+#define safe_syscall3(type, name, type1, arg1, type2, arg2, type3, arg3) \
+static type safe_##name(type1 arg1, type2 arg2, type3 arg3) \
+{ \
+    return safe_syscall(__NR_##name, arg1, arg2, arg3); \
+}
+
+#define safe_syscall4(type, name, type1, arg1, type2, arg2, type3, arg3, \
+    type4, arg4) \
+static type safe_##name(type1 arg1, type2 arg2, type3 arg3, type4 arg4) \
+{ \
+    return safe_syscall(__NR_##name, arg1, arg2, arg3, arg4); \
+}
+
+#define safe_syscall5(type, name, type1, arg1, type2, arg2, type3, arg3, \
+    type4, arg4, type5, arg5) \
+static type safe_##name(type1 arg1, type2 arg2, type3 arg3, type4 arg4, \
+    type5 arg5) \
+{ \
+    return safe_syscall(__NR_##name, arg1, arg2, arg3, arg4, arg5); \
+}
+
+#define safe_syscall6(type, name, type1, arg1, type2, arg2, type3, arg3, \
+    type4, arg4, type5, arg5, type6, arg6) \
+static type safe_##name(type1 arg1, type2 arg2, type3 arg3, type4 arg4, \
+    type5 arg5, type6 arg6) \
+{ \
+    return safe_syscall(__NR_##name, arg1, arg2, arg3, arg4, arg5, arg6); \
+}
+
 static inline int host_to_target_sock_type(int host_type)
 {
     int target_type;
