Darwin userspace emulation, by Pierre d'Herbemont.

git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@2332 c046a42c-6fe2-441c-8c8c-71466251a162

1 files changed, 463 insertions, 0 deletions

diff --git a/darwin-user/signal.c b/darwin-user/signal.c
new file mode 100644
index 0000000000..a0b9f89dcc
--- /dev/null
+++ b/darwin-user/signal.c
@@ -0,0 +1,463 @@
+/*
+ *  Emulation of Linux signals
+ *
+ *  Copyright (c) 2003 Fabrice Bellard
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to the Free Software
+ *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <stdarg.h>
+#include <unistd.h>
+#include <signal.h>
+#include <errno.h>
+#include <sys/ucontext.h>
+
+#ifdef __ia64__
+#undef uc_mcontext
+#undef uc_sigmask
+#undef uc_stack
+#undef uc_link
+#endif
+
+#include <signal.h>
+
+#include "qemu.h"
+
+#define DEBUG_SIGNAL
+
+#define MAX_SIGQUEUE_SIZE 1024
+
+struct sigqueue {
+    struct sigqueue *next;
+    target_siginfo_t info;
+};
+
+struct emulated_sigaction {
+    struct target_sigaction sa;
+    int pending; /* true if signal is pending */
+    struct sigqueue *first;
+    struct sigqueue info; /* in order to always have memory for the
+                             first signal, we put it here */
+};
+
+struct sigaltstack target_sigaltstack_used = {
+    0, 0, SA_DISABLE
+};
+
+static struct emulated_sigaction sigact_table[NSIG];
+static struct sigqueue sigqueue_table[MAX_SIGQUEUE_SIZE]; /* siginfo queue */
+static struct sigqueue *first_free; /* first free siginfo queue entry */
+static int signal_pending; /* non zero if a signal may be pending */
+
+static void host_signal_handler(int host_signum, siginfo_t *info,
+                                void *puc);
+
+
+static inline int host_to_target_signal(int sig)
+{
+    return sig;
+}
+
+static inline int target_to_host_signal(int sig)
+{
+    return sig;
+}
+
+/* siginfo conversion */
+
+
+
+void host_to_target_siginfo(target_siginfo_t *tinfo, const siginfo_t *info)
+{
+
+}
+
+void target_to_host_siginfo(siginfo_t *info, const target_siginfo_t *tinfo)
+{
+
+}
+
+void signal_init(void)
+{
+    struct sigaction act;
+    int i;
+
+    /* set all host signal handlers. ALL signals are blocked during
+       the handlers to serialize them. */
+    sigfillset(&act.sa_mask);
+    act.sa_flags = SA_SIGINFO;
+    act.sa_sigaction = host_signal_handler;
+    for(i = 1; i < NSIG; i++) {
+        sigaction(i, &act, NULL);
+    }
+
+    memset(sigact_table, 0, sizeof(sigact_table));
+
+    first_free = &sigqueue_table[0];
+    for(i = 0; i < MAX_SIGQUEUE_SIZE - 1; i++)
+        sigqueue_table[i].next = &sigqueue_table[i + 1];
+    sigqueue_table[MAX_SIGQUEUE_SIZE - 1].next = NULL;
+}
+
+/* signal queue handling */
+
+static inline struct sigqueue *alloc_sigqueue(void)
+{
+    struct sigqueue *q = first_free;
+    if (!q)
+        return NULL;
+    first_free = q->next;
+    return q;
+}
+
+static inline void free_sigqueue(struct sigqueue *q)
+{
+    q->next = first_free;
+    first_free = q;
+}
+
+/* abort execution with signal */
+void __attribute((noreturn)) force_sig(int sig)
+{
+    int host_sig;
+    host_sig = target_to_host_signal(sig);
+    fprintf(stderr, "qemu: uncaught target signal %d (%s) - exiting\n",
+            sig, strsignal(host_sig));
+    _exit(-host_sig);
+}
+
+/* queue a signal so that it will be send to the virtual CPU as soon
+   as possible */
+int queue_signal(int sig, target_siginfo_t *info)
+{
+    struct emulated_sigaction *k;
+    struct sigqueue *q, **pq;
+    target_ulong handler;
+
+#if defined(DEBUG_SIGNAL)
+    fprintf(stderr, "queue_signal: sig=%d\n",
+            sig);
+#endif
+    k = &sigact_table[sig - 1];
+    handler = (target_ulong)k->sa.sa_handler;
+    if (handler == SIG_DFL) {
+        /* default handler : ignore some signal. The other are fatal */
+        if (sig != SIGCHLD &&
+            sig != SIGURG &&
+            sig != SIGWINCH) {
+            force_sig(sig);
+        } else {
+            return 0; /* indicate ignored */
+        }
+    } else if (handler == host_to_target_signal(SIG_IGN)) {
+        /* ignore signal */
+        return 0;
+    } else if (handler == host_to_target_signal(SIG_ERR)) {
+        force_sig(sig);
+    } else {
+        pq = &k->first;
+        if (!k->pending) {
+            /* first signal */
+            q = &k->info;
+        } else {
+            q = alloc_sigqueue();
+            if (!q)
+                return -EAGAIN;
+            while (*pq != NULL)
+                pq = &(*pq)->next;
+        }
+        *pq = q;
+        q->info = *info;
+        q->next = NULL;
+        k->pending = 1;
+        /* signal that a new signal is pending */
+        signal_pending = 1;
+        return 1; /* indicates that the signal was queued */
+    }
+}
+
+static void host_signal_handler(int host_signum, siginfo_t *info,
+                                void *puc)
+{
+    int sig;
+    target_siginfo_t tinfo;
+
+    /* the CPU emulator uses some host signals to detect exceptions,
+       we we forward to it some signals */
+    if (host_signum == SIGSEGV || host_signum == SIGBUS
+#if defined(TARGET_I386) && defined(USE_CODE_COPY)
+        || host_signum == SIGFPE
+#endif
+        ) {
+        if (cpu_signal_handler(host_signum, (void*)info, puc))
+            return;
+    }
+
+    /* get target signal number */
+    sig = host_to_target_signal(host_signum);
+    if (sig < 1 || sig > NSIG)
+        return;
+
+#if defined(DEBUG_SIGNAL)
+	fprintf(stderr, "qemu: got signal %d\n", sig);
+#endif
+    if (queue_signal(sig, &tinfo) == 1) {
+        /* interrupt the virtual CPU as soon as possible */
+        cpu_interrupt(global_env, CPU_INTERRUPT_EXIT);
+    }
+}
+
+int do_sigaltstack(const struct sigaltstack *ss, struct sigaltstack *oss)
+{
+    /* XXX: test errors */
+    if(oss)
+    {
+        oss->ss_sp = tswap32(target_sigaltstack_used.ss_sp);
+        oss->ss_size = tswap32(target_sigaltstack_used.ss_size);
+        oss->ss_flags = tswap32(target_sigaltstack_used.ss_flags);
+    }
+    if(ss)
+    {
+        target_sigaltstack_used.ss_sp = tswap32(ss->ss_sp);
+        target_sigaltstack_used.ss_size = tswap32(ss->ss_size);
+        target_sigaltstack_used.ss_flags = tswap32(ss->ss_flags);
+    }
+    return 0;
+}
+
+int do_sigaction(int sig, const struct sigaction *act,
+                 struct sigaction *oact)
+{
+    struct emulated_sigaction *k;
+    struct sigaction act1;
+    int host_sig;
+
+    if (sig < 1 || sig > NSIG)
+        return -EINVAL;
+
+    k = &sigact_table[sig - 1];
+#if defined(DEBUG_SIGNAL)
+    fprintf(stderr, "sigaction 1 sig=%d act=0x%08x, oact=0x%08x\n",
+            sig, (int)act, (int)oact);
+#endif
+    if (oact) {
+#if defined(DEBUG_SIGNAL)
+    fprintf(stderr, "sigaction 1 sig=%d act=0x%08x, oact=0x%08x\n",
+            sig, (int)act, (int)oact);
+#endif
+
+        oact->sa_handler = tswapl(k->sa.sa_handler);
+        oact->sa_flags = tswapl(k->sa.sa_flags);
+        oact->sa_mask = tswapl(k->sa.sa_mask);
+    }
+    if (act) {
+#if defined(DEBUG_SIGNAL)
+    fprintf(stderr, "sigaction handler 0x%x flag 0x%x mask 0x%x\n",
+            act->sa_handler, act->sa_flags, act->sa_mask);
+#endif
+
+        k->sa.sa_handler = tswapl(act->sa_handler);
+        k->sa.sa_flags = tswapl(act->sa_flags);
+        k->sa.sa_mask = tswapl(act->sa_mask);
+        /* we update the host signal state */
+        host_sig = target_to_host_signal(sig);
+        if (host_sig != SIGSEGV && host_sig != SIGBUS) {
+#if defined(DEBUG_SIGNAL)
+    fprintf(stderr, "sigaction handler going to call sigaction\n",
+            act->sa_handler, act->sa_flags, act->sa_mask);
+#endif
+
+            sigfillset(&act1.sa_mask);
+            act1.sa_flags = SA_SIGINFO;
+            if (k->sa.sa_flags & SA_RESTART)
+                act1.sa_flags |= SA_RESTART;
+            /* NOTE: it is important to update the host kernel signal
+               ignore state to avoid getting unexpected interrupted
+               syscalls */
+            if (k->sa.sa_handler == SIG_IGN) {
+                act1.sa_sigaction = (void *)SIG_IGN;
+            } else if (k->sa.sa_handler == SIG_DFL) {
+                act1.sa_sigaction = (void *)SIG_DFL;
+            } else {
+                act1.sa_sigaction = host_signal_handler;
+            }
+            sigaction(host_sig, &act1, NULL);
+        }
+    }
+    return 0;
+}
+
+
+#ifdef TARGET_I386
+
+static inline void *
+get_sigframe(struct emulated_sigaction *ka, CPUX86State *env, size_t frame_size)
+{
+    /* XXX Fix that */
+    if(target_sigaltstack_used.ss_flags & SA_DISABLE)
+    {
+        int esp;
+        /* Default to using normal stack */
+        esp = env->regs[R_ESP];
+
+        return (void *)((esp - frame_size) & -8ul);
+    }
+    else
+    {
+        return target_sigaltstack_used.ss_sp;
+    }
+}
+
+static void setup_frame(int sig, struct emulated_sigaction *ka,
+			void *set, CPUState *env)
+{
+	void *frame;
+	int i, err = 0;
+
+    fprintf(stderr, "setup_frame %d\n", sig);
+	frame = get_sigframe(ka, env, sizeof(*frame));
+
+	/* Set up registers for signal handler */
+	env->regs[R_ESP] = (unsigned long) frame;
+	env->eip = (unsigned long) ka->sa.sa_handler;
+
+	env->eflags &= ~TF_MASK;
+
+	return;
+
+give_sigsegv:
+	if (sig == SIGSEGV)
+		ka->sa.sa_handler = SIG_DFL;
+	force_sig(SIGSEGV /* , current */);
+}
+
+long do_sigreturn(CPUState *env, int num)
+{
+    int i = 0;
+    struct target_sigcontext *scp = get_int_arg(&i, env);
+    /* XXX Get current signal number */
+    /* XXX Adjust accordin to sc_onstack, sc_mask */
+    if(tswapl(scp->sc_onstack) & 0x1)
+        target_sigaltstack_used.ss_flags |= ~SA_DISABLE;
+    else
+        target_sigaltstack_used.ss_flags &=  SA_DISABLE;
+    int set = tswapl(scp->sc_eax);
+    sigprocmask(SIG_SETMASK, &set, NULL);
+
+    fprintf(stderr, "do_sigreturn: partially implemented %x EAX:%x EBX:%x\n", scp->sc_mask, tswapl(scp->sc_eax), tswapl(scp->sc_ebx));
+    fprintf(stderr, "ECX:%x EDX:%x EDI:%x\n", scp->sc_ecx, tswapl(scp->sc_edx), tswapl(scp->sc_edi));
+    fprintf(stderr, "EIP:%x\n", tswapl(scp->sc_eip));
+
+    env->regs[R_EAX] = tswapl(scp->sc_eax);
+    env->regs[R_EBX] = tswapl(scp->sc_ebx);
+    env->regs[R_ECX] = tswapl(scp->sc_ecx);
+    env->regs[R_EDX] = tswapl(scp->sc_edx);
+    env->regs[R_EDI] = tswapl(scp->sc_edi);
+    env->regs[R_ESI] = tswapl(scp->sc_esi);
+    env->regs[R_EBP] = tswapl(scp->sc_ebp);
+    env->regs[R_ESP] = tswapl(scp->sc_esp);
+    env->segs[R_SS].selector = (void*)tswapl(scp->sc_ss);
+    env->eflags = tswapl(scp->sc_eflags);
+    env->eip = tswapl(scp->sc_eip);
+    env->segs[R_CS].selector = (void*)tswapl(scp->sc_cs);
+    env->segs[R_DS].selector = (void*)tswapl(scp->sc_ds);
+    env->segs[R_ES].selector = (void*)tswapl(scp->sc_es);
+    env->segs[R_FS].selector = (void*)tswapl(scp->sc_fs);
+    env->segs[R_GS].selector = (void*)tswapl(scp->sc_gs);
+
+    /* Again, because our caller's caller will reset EAX */
+    return env->regs[R_EAX];
+}
+
+#else
+
+static void setup_frame(int sig, struct emulated_sigaction *ka,
+			void *set, CPUState *env)
+{
+    fprintf(stderr, "setup_frame: not implemented\n");
+}
+
+long do_sigreturn(CPUState *env, int num)
+{
+    int i = 0;
+    struct target_sigcontext *scp = get_int_arg(&i, env);
+    fprintf(stderr, "do_sigreturn: not implemented\n");
+    return -ENOSYS;
+}
+
+#endif
+
+void process_pending_signals(void *cpu_env)
+{
+    struct emulated_sigaction *k;
+    struct sigqueue *q;
+    target_ulong handler;
+    int sig;
+
+    if (!signal_pending)
+        return;
+
+    k = sigact_table;
+
+    for(sig = 1; sig <= NSIG; sig++) {
+        if (k->pending)
+            goto handle_signal;
+        k++;
+    }
+
+    /* if no signal is pending, just return */
+    signal_pending = 0;
+    return;
+handle_signal:
+    #ifdef DEBUG_SIGNAL
+    fprintf(stderr, "qemu: process signal %d\n", sig);
+    #endif
+    /* dequeue signal */
+    q = k->first;
+    k->first = q->next;
+    if (!k->first)
+        k->pending = 0;
+
+    sig = gdb_handlesig (cpu_env, sig);
+    if (!sig) {
+        fprintf (stderr, "Lost signal\n");
+        abort();
+    }
+
+    handler = k->sa.sa_handler;
+    if (handler == SIG_DFL) {
+        /* default handler : ignore some signal. The other are fatal */
+        if (sig != SIGCHLD &&
+            sig != SIGURG &&
+            sig != SIGWINCH) {
+            force_sig(sig);
+        }
+    } else if (handler == SIG_IGN) {
+        /* ignore sig */
+    } else if (handler == SIG_ERR) {
+        force_sig(sig);
+    } else {
+
+        setup_frame(sig, k, 0, cpu_env);
+	if (k->sa.sa_flags & SA_RESETHAND)
+            k->sa.sa_handler = SIG_DFL;
+    }
+    if (q != &k->info)
+        free_sigqueue(q);
+}
+
+