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authorbellard <bellard@c046a42c-6fe2-441c-8c8c-71466251a162>2003-03-23 16:49:39 +0000
committerbellard <bellard@c046a42c-6fe2-441c-8c8c-71466251a162>2003-03-23 16:49:39 +0000
commit9de5e440b9f6a6c6305c0b81d1df4ddcc5a4b966 (patch)
tree718d0257eb2e9cac1196bd8ca83dfd11c15fd475 /linux-user/signal.c
parent66fb9763af9cd743158957e8c9c2559d922b1c22 (diff)
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better signal/exception support
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@42 c046a42c-6fe2-441c-8c8c-71466251a162
Diffstat (limited to 'linux-user/signal.c')
-rw-r--r--linux-user/signal.c244
1 files changed, 183 insertions, 61 deletions
diff --git a/linux-user/signal.c b/linux-user/signal.c
index 61baf99..3e792ae 100644
--- a/linux-user/signal.c
+++ b/linux-user/signal.c
@@ -27,13 +27,6 @@
#include "gemu.h"
-#include "syscall_defs.h"
-
-#ifdef TARGET_I386
-#include "cpu-i386.h"
-#include "syscall-i386.h"
-#endif
-
/* signal handling inspired from em86. */
//#define DEBUG_SIGNAL
@@ -42,7 +35,7 @@
struct sigqueue {
struct sigqueue *next;
- siginfo_t info;
+ target_siginfo_t info;
};
struct emulated_sigaction {
@@ -101,20 +94,66 @@ void target_to_host_old_sigset(sigset_t *sigset,
*(unsigned long *)sigset = tswapl(*old_sigset);
}
-/* XXX: finish it */
-void host_to_target_siginfo(target_siginfo_t *tinfo, siginfo_t *info)
+/* siginfo conversion */
+
+static inline void host_to_target_siginfo_noswap(target_siginfo_t *tinfo,
+ const siginfo_t *info)
{
- tinfo->si_signo = tswap32(info->si_signo);
+ int sig;
+ sig = host_to_target_signal(info->si_signo);
+ tinfo->si_signo = sig;
+ tinfo->si_errno = 0;
+ tinfo->si_code = 0;
+ if (sig == SIGILL || sig == SIGFPE || sig == SIGSEGV || sig == SIGBUS) {
+ /* should never come here, but who knows. The information for
+ the target is irrelevant */
+ tinfo->_sifields._sigfault._addr = 0;
+ } else if (sig >= TARGET_SIGRTMIN) {
+ tinfo->_sifields._rt._pid = info->si_pid;
+ tinfo->_sifields._rt._uid = info->si_uid;
+ /* XXX: potential problem if 64 bit */
+ tinfo->_sifields._rt._sigval.sival_ptr =
+ (target_ulong)info->si_value.sival_ptr;
+ }
+}
+
+static void tswap_siginfo(target_siginfo_t *tinfo,
+ const target_siginfo_t *info)
+{
+ int sig;
+ sig = info->si_signo;
+ tinfo->si_signo = tswap32(sig);
tinfo->si_errno = tswap32(info->si_errno);
tinfo->si_code = tswap32(info->si_code);
+ if (sig == SIGILL || sig == SIGFPE || sig == SIGSEGV || sig == SIGBUS) {
+ tinfo->_sifields._sigfault._addr =
+ tswapl(info->_sifields._sigfault._addr);
+ } else if (sig >= TARGET_SIGRTMIN) {
+ tinfo->_sifields._rt._pid = tswap32(info->_sifields._rt._pid);
+ tinfo->_sifields._rt._uid = tswap32(info->_sifields._rt._uid);
+ tinfo->_sifields._rt._sigval.sival_ptr =
+ tswapl(info->_sifields._rt._sigval.sival_ptr);
+ }
+}
+
+
+void host_to_target_siginfo(target_siginfo_t *tinfo, const siginfo_t *info)
+{
+ host_to_target_siginfo_noswap(tinfo, info);
+ tswap_siginfo(tinfo, tinfo);
}
-/* XXX: finish it */
-void target_to_host_siginfo(siginfo_t *info, target_siginfo_t *tinfo)
+/* XXX: we support only POSIX RT signals are used. */
+/* XXX: find a solution for 64 bit (additionnal malloced data is needed) */
+void target_to_host_siginfo(siginfo_t *info, const target_siginfo_t *tinfo)
{
info->si_signo = tswap32(tinfo->si_signo);
info->si_errno = tswap32(tinfo->si_errno);
info->si_code = tswap32(tinfo->si_code);
+ info->si_pid = tswap32(tinfo->_sifields._rt._pid);
+ info->si_uid = tswap32(tinfo->_sifields._rt._uid);
+ info->si_value.sival_ptr =
+ (void *)tswapl(tinfo->_sifields._rt._sigval.sival_ptr);
}
void signal_init(void)
@@ -122,8 +161,9 @@ void signal_init(void)
struct sigaction act;
int i;
- /* set all host signal handlers */
- sigemptyset(&act.sa_mask);
+ /* 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++) {
@@ -155,56 +195,40 @@ static inline void free_sigqueue(struct sigqueue *q)
first_free = q;
}
-static int queue_signal(struct emulated_sigaction *k, int sig, siginfo_t *info)
-{
- struct sigqueue *q, **pq;
-
- pq = &k->first;
- if (!k->pending || sig < TARGET_SIGRTMIN) {
- /* first signal or non real time 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 0;
-}
-
-void force_sig(int sig)
+/* abort execution with signal */
+void __attribute((noreturn)) force_sig(int sig)
{
int host_sig;
- /* abort execution with signal */
host_sig = target_to_host_signal(sig);
fprintf(stderr, "gemu: uncaught target signal %d (%s) - exiting\n",
sig, strsignal(host_sig));
+#if 1
_exit(-host_sig);
+#else
+ {
+ struct sigaction act;
+ sigemptyset(&act.sa_mask);
+ act.sa_flags = SA_SIGINFO;
+ act.sa_sigaction = SIG_DFL;
+ sigaction(SIGABRT, &act, NULL);
+ abort();
+ }
+#endif
}
-
-static void host_signal_handler(int host_signum, siginfo_t *info,
- void *puc)
+/* 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;
- int sig;
+ struct sigqueue *q, **pq;
target_ulong handler;
- /* get target signal number */
- sig = host_to_target_signal(host_signum);
- if (sig < 1 || sig > TARGET_NSIG)
- return;
- k = &sigact_table[sig - 1];
-#ifdef DEBUG_SIGNAL
- fprintf(stderr, "gemu: got signal %d\n", sig);
+#if defined(DEBUG_SIGNAL)
+ fprintf(stderr, "queue_sigal: sig=%d\n",
+ sig);
#endif
+ k = &sigact_table[sig - 1];
handler = k->sa._sa_handler;
if (handler == TARGET_SIG_DFL) {
/* default handler : ignore some signal. The other are fatal */
@@ -212,13 +236,96 @@ static void host_signal_handler(int host_signum, siginfo_t *info,
sig != TARGET_SIGURG &&
sig != TARGET_SIGWINCH) {
force_sig(sig);
+ } else {
+ return 0; /* indicate ignored */
}
} else if (handler == TARGET_SIG_IGN) {
/* ignore signal */
+ return 0;
} else if (handler == TARGET_SIG_ERR) {
force_sig(sig);
} else {
- queue_signal(k, sig, info);
+ pq = &k->first;
+ if (sig < TARGET_SIGRTMIN) {
+ /* if non real time signal, we queue exactly one signal */
+ if (!k->pending)
+ q = &k->info;
+ else
+ return 0;
+ } else {
+ 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 */
+ }
+}
+
+#if defined(DEBUG_SIGNAL)
+#ifdef __i386__
+static void dump_regs(struct ucontext *uc)
+{
+ fprintf(stderr,
+ "EAX=%08x EBX=%08x ECX=%08x EDX=%08x\n"
+ "ESI=%08x EDI=%08x EBP=%08x ESP=%08x\n"
+ "EFL=%08x EIP=%08x\n",
+ uc->uc_mcontext.gregs[EAX],
+ uc->uc_mcontext.gregs[EBX],
+ uc->uc_mcontext.gregs[ECX],
+ uc->uc_mcontext.gregs[EDX],
+ uc->uc_mcontext.gregs[ESI],
+ uc->uc_mcontext.gregs[EDI],
+ uc->uc_mcontext.gregs[EBP],
+ uc->uc_mcontext.gregs[ESP],
+ uc->uc_mcontext.gregs[EFL],
+ uc->uc_mcontext.gregs[EIP]);
+}
+#else
+static void dump_regs(struct ucontext *uc)
+{
+}
+#endif
+
+#endif
+
+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 (cpu_x86_signal_handler(host_signum, info, puc))
+ return;
+ }
+
+ /* get target signal number */
+ sig = host_to_target_signal(host_signum);
+ if (sig < 1 || sig > TARGET_NSIG)
+ return;
+#if defined(DEBUG_SIGNAL)
+ fprintf(stderr, "gemu: got signal %d\n", sig);
+ dump_regs(puc);
+#endif
+ host_to_target_siginfo_noswap(&tinfo, info);
+ if (queue_signal(sig, &tinfo) == 1) {
+ /* interrupt the virtual CPU as soon as possible */
+ cpu_x86_interrupt(global_env);
}
}
@@ -388,9 +495,10 @@ struct rt_sigframe
0;\
})
-static inline int copy_siginfo_to_user(target_siginfo_t *tinfo, siginfo_t *info)
+static inline int copy_siginfo_to_user(target_siginfo_t *tinfo,
+ const target_siginfo_t *info)
{
- host_to_target_siginfo(tinfo, info);
+ tswap_siginfo(tinfo, info);
return 0;
}
@@ -531,7 +639,8 @@ give_sigsegv:
force_sig(TARGET_SIGSEGV /* , current */);
}
-static void setup_rt_frame(int sig, struct emulated_sigaction *ka, siginfo_t *info,
+static void setup_rt_frame(int sig, struct emulated_sigaction *ka,
+ target_siginfo_t *info,
target_sigset_t *set, CPUX86State *env)
{
struct rt_sigframe *frame;
@@ -734,7 +843,8 @@ void process_pending_signals(void *cpu_env)
{
int sig;
target_ulong handler;
- target_sigset_t set;
+ sigset_t set, old_set;
+ target_sigset_t target_old_set;
struct emulated_sigaction *k;
struct sigqueue *q;
@@ -774,12 +884,24 @@ void process_pending_signals(void *cpu_env)
} else if (handler == TARGET_SIG_ERR) {
force_sig(sig);
} else {
- set = k->sa.sa_mask;
- /* send the signal to the CPU */
+ /* compute the blocked signals during the handler execution */
+ target_to_host_sigset(&set, &k->sa.sa_mask);
+ /* SA_NODEFER indicates that the current signal should not be
+ blocked during the handler */
+ if (!(k->sa.sa_flags & TARGET_SA_NODEFER))
+ sigaddset(&set, target_to_host_signal(sig));
+
+ /* block signals in the handler using Linux */
+ sigprocmask(SIG_BLOCK, &set, &old_set);
+ /* save the previous blocked signal state to restore it at the
+ end of the signal execution (see do_sigreturn) */
+ host_to_target_sigset(&target_old_set, &old_set);
+
+ /* prepare the stack frame of the virtual CPU */
if (k->sa.sa_flags & TARGET_SA_SIGINFO)
- setup_rt_frame(sig, k, &q->info, &set, cpu_env);
+ setup_rt_frame(sig, k, &q->info, &target_old_set, cpu_env);
else
- setup_frame(sig, k, &set, cpu_env);
+ setup_frame(sig, k, &target_old_set, cpu_env);
if (k->sa.sa_flags & TARGET_SA_RESETHAND)
k->sa._sa_handler = TARGET_SIG_DFL;
}