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authoraurel32 <aurel32@c046a42c-6fe2-441c-8c8c-71466251a162>2008-12-18 22:44:13 +0000
committeraurel32 <aurel32@c046a42c-6fe2-441c-8c8c-71466251a162>2008-12-18 22:44:13 +0000
commitca587a8ebdb4bfb30d3080ea5721882209911670 (patch)
tree1e142646b615560244a1a05f822dc9c0f775f522
parentUser-mode GDB stub improvements - handle fork (diff)
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User-mode GDB stub improvements - handle signals
Handle signals in the user-mode GDB stub. Report them to GDB, and allow it to change or cancel them. Also correct the protocol numbering; it happens to match Linux numbering for SIGINT and SIGTRAP, but that's just good fortune. Signed-off-by: Daniel Jacobowitz <dan@codesourcery.com> Acked-by: Edgar E. Iglesias <edgar.iglesias@gmail.com> Signed-off-by: Aurelien Jarno <aurelien@aurel32.net> git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6096 c046a42c-6fe2-441c-8c8c-71466251a162
-rw-r--r--gdbstub.c254
-rw-r--r--gdbstub.h2
-rw-r--r--linux-user/signal.c65
3 files changed, 290 insertions, 31 deletions
diff --git a/gdbstub.c b/gdbstub.c
index 2e112b252..f7c065c95 100644
--- a/gdbstub.c
+++ b/gdbstub.c
@@ -38,18 +38,213 @@
#define MAX_PACKET_LENGTH 4096
#include "qemu_socket.h"
-#ifdef _WIN32
-/* XXX: these constants may be independent of the host ones even for Unix */
-#ifndef SIGTRAP
-#define SIGTRAP 5
-#endif
-#ifndef SIGINT
-#define SIGINT 2
-#endif
+
+
+enum {
+ GDB_SIGNAL_0 = 0,
+ GDB_SIGNAL_INT = 2,
+ GDB_SIGNAL_TRAP = 5,
+ GDB_SIGNAL_UNKNOWN = 143
+};
+
+#ifdef CONFIG_USER_ONLY
+
+/* Map target signal numbers to GDB protocol signal numbers and vice
+ * versa. For user emulation's currently supported systems, we can
+ * assume most signals are defined.
+ */
+
+static int gdb_signal_table[] = {
+ 0,
+ TARGET_SIGHUP,
+ TARGET_SIGINT,
+ TARGET_SIGQUIT,
+ TARGET_SIGILL,
+ TARGET_SIGTRAP,
+ TARGET_SIGABRT,
+ -1, /* SIGEMT */
+ TARGET_SIGFPE,
+ TARGET_SIGKILL,
+ TARGET_SIGBUS,
+ TARGET_SIGSEGV,
+ TARGET_SIGSYS,
+ TARGET_SIGPIPE,
+ TARGET_SIGALRM,
+ TARGET_SIGTERM,
+ TARGET_SIGURG,
+ TARGET_SIGSTOP,
+ TARGET_SIGTSTP,
+ TARGET_SIGCONT,
+ TARGET_SIGCHLD,
+ TARGET_SIGTTIN,
+ TARGET_SIGTTOU,
+ TARGET_SIGIO,
+ TARGET_SIGXCPU,
+ TARGET_SIGXFSZ,
+ TARGET_SIGVTALRM,
+ TARGET_SIGPROF,
+ TARGET_SIGWINCH,
+ -1, /* SIGLOST */
+ TARGET_SIGUSR1,
+ TARGET_SIGUSR2,
+ TARGET_SIGPWR,
+ -1, /* SIGPOLL */
+ -1,
+ -1,
+ -1,
+ -1,
+ -1,
+ -1,
+ -1,
+ -1,
+ -1,
+ -1,
+ -1,
+ __SIGRTMIN + 1,
+ __SIGRTMIN + 2,
+ __SIGRTMIN + 3,
+ __SIGRTMIN + 4,
+ __SIGRTMIN + 5,
+ __SIGRTMIN + 6,
+ __SIGRTMIN + 7,
+ __SIGRTMIN + 8,
+ __SIGRTMIN + 9,
+ __SIGRTMIN + 10,
+ __SIGRTMIN + 11,
+ __SIGRTMIN + 12,
+ __SIGRTMIN + 13,
+ __SIGRTMIN + 14,
+ __SIGRTMIN + 15,
+ __SIGRTMIN + 16,
+ __SIGRTMIN + 17,
+ __SIGRTMIN + 18,
+ __SIGRTMIN + 19,
+ __SIGRTMIN + 20,
+ __SIGRTMIN + 21,
+ __SIGRTMIN + 22,
+ __SIGRTMIN + 23,
+ __SIGRTMIN + 24,
+ __SIGRTMIN + 25,
+ __SIGRTMIN + 26,
+ __SIGRTMIN + 27,
+ __SIGRTMIN + 28,
+ __SIGRTMIN + 29,
+ __SIGRTMIN + 30,
+ __SIGRTMIN + 31,
+ -1, /* SIGCANCEL */
+ __SIGRTMIN,
+ __SIGRTMIN + 32,
+ __SIGRTMIN + 33,
+ __SIGRTMIN + 34,
+ __SIGRTMIN + 35,
+ __SIGRTMIN + 36,
+ __SIGRTMIN + 37,
+ __SIGRTMIN + 38,
+ __SIGRTMIN + 39,
+ __SIGRTMIN + 40,
+ __SIGRTMIN + 41,
+ __SIGRTMIN + 42,
+ __SIGRTMIN + 43,
+ __SIGRTMIN + 44,
+ __SIGRTMIN + 45,
+ __SIGRTMIN + 46,
+ __SIGRTMIN + 47,
+ __SIGRTMIN + 48,
+ __SIGRTMIN + 49,
+ __SIGRTMIN + 50,
+ __SIGRTMIN + 51,
+ __SIGRTMIN + 52,
+ __SIGRTMIN + 53,
+ __SIGRTMIN + 54,
+ __SIGRTMIN + 55,
+ __SIGRTMIN + 56,
+ __SIGRTMIN + 57,
+ __SIGRTMIN + 58,
+ __SIGRTMIN + 59,
+ __SIGRTMIN + 60,
+ __SIGRTMIN + 61,
+ __SIGRTMIN + 62,
+ __SIGRTMIN + 63,
+ __SIGRTMIN + 64,
+ __SIGRTMIN + 65,
+ __SIGRTMIN + 66,
+ __SIGRTMIN + 67,
+ __SIGRTMIN + 68,
+ __SIGRTMIN + 69,
+ __SIGRTMIN + 70,
+ __SIGRTMIN + 71,
+ __SIGRTMIN + 72,
+ __SIGRTMIN + 73,
+ __SIGRTMIN + 74,
+ __SIGRTMIN + 75,
+ __SIGRTMIN + 76,
+ __SIGRTMIN + 77,
+ __SIGRTMIN + 78,
+ __SIGRTMIN + 79,
+ __SIGRTMIN + 80,
+ __SIGRTMIN + 81,
+ __SIGRTMIN + 82,
+ __SIGRTMIN + 83,
+ __SIGRTMIN + 84,
+ __SIGRTMIN + 85,
+ __SIGRTMIN + 86,
+ __SIGRTMIN + 87,
+ __SIGRTMIN + 88,
+ __SIGRTMIN + 89,
+ __SIGRTMIN + 90,
+ __SIGRTMIN + 91,
+ __SIGRTMIN + 92,
+ __SIGRTMIN + 93,
+ __SIGRTMIN + 94,
+ __SIGRTMIN + 95,
+ -1, /* SIGINFO */
+ -1, /* UNKNOWN */
+ -1, /* DEFAULT */
+ -1,
+ -1,
+ -1,
+ -1,
+ -1,
+ -1
+};
#else
-#include <signal.h>
+/* In system mode we only need SIGINT and SIGTRAP; other signals
+ are not yet supported. */
+
+enum {
+ TARGET_SIGINT = 2,
+ TARGET_SIGTRAP = 5
+};
+
+static int gdb_signal_table[] = {
+ -1,
+ -1,
+ TARGET_SIGINT,
+ -1,
+ -1,
+ TARGET_SIGTRAP
+};
+#endif
+
+#ifdef CONFIG_USER_ONLY
+static int target_signal_to_gdb (int sig)
+{
+ int i;
+ for (i = 0; i < ARRAY_SIZE (gdb_signal_table); i++)
+ if (gdb_signal_table[i] == sig)
+ return i;
+ return GDB_SIGNAL_UNKNOWN;
+}
#endif
+static int gdb_signal_to_target (int sig)
+{
+ if (sig < ARRAY_SIZE (gdb_signal_table))
+ return gdb_signal_table[sig];
+ else
+ return -1;
+}
+
//#define DEBUG_GDB
typedef struct GDBRegisterState {
@@ -1300,7 +1495,7 @@ static int gdb_handle_packet(GDBState *s, const char *line_buf)
switch(ch) {
case '?':
/* TODO: Make this return the correct value for user-mode. */
- snprintf(buf, sizeof(buf), "T%02xthread:%02x;", SIGTRAP,
+ snprintf(buf, sizeof(buf), "T%02xthread:%02x;", GDB_SIGNAL_TRAP,
s->c_cpu->cpu_index+1);
put_packet(s, buf);
/* Remove all the breakpoints when this query is issued,
@@ -1331,10 +1526,13 @@ static int gdb_handle_packet(GDBState *s, const char *line_buf)
s->c_cpu->pc = addr;
#endif
}
+ s->signal = 0;
gdb_continue(s);
return RS_IDLE;
case 'C':
- s->signal = strtoul(p, (char **)&p, 16);
+ s->signal = gdb_signal_to_target (strtoul(p, (char **)&p, 16));
+ if (s->signal == -1)
+ s->signal = 0;
gdb_continue(s);
return RS_IDLE;
case 'k':
@@ -1692,16 +1890,16 @@ static void gdb_vm_stopped(void *opaque, int reason)
}
snprintf(buf, sizeof(buf),
"T%02xthread:%02x;%swatch:" TARGET_FMT_lx ";",
- SIGTRAP, env->cpu_index+1, type,
+ GDB_SIGNAL_TRAP, env->cpu_index+1, type,
env->watchpoint_hit->vaddr);
put_packet(s, buf);
env->watchpoint_hit = NULL;
return;
}
tb_flush(env);
- ret = SIGTRAP;
+ ret = GDB_SIGNAL_TRAP;
} else if (reason == EXCP_INTERRUPT) {
- ret = SIGINT;
+ ret = GDB_SIGNAL_INT;
} else {
ret = 0;
}
@@ -1853,6 +2051,19 @@ static void gdb_read_byte(GDBState *s, int ch)
#ifdef CONFIG_USER_ONLY
int
+gdb_queuesig (void)
+{
+ GDBState *s;
+
+ s = gdbserver_state;
+
+ if (gdbserver_fd < 0 || s->fd < 0)
+ return 0;
+ else
+ return 1;
+}
+
+int
gdb_handlesig (CPUState *env, int sig)
{
GDBState *s;
@@ -1869,7 +2080,7 @@ gdb_handlesig (CPUState *env, int sig)
if (sig != 0)
{
- snprintf(buf, sizeof(buf), "S%02x", sig);
+ snprintf(buf, sizeof(buf), "S%02x", target_signal_to_gdb (sig));
put_packet(s, buf);
}
/* put_packet() might have detected that the peer terminated the
@@ -1915,6 +2126,19 @@ void gdb_exit(CPUState *env, int code)
put_packet(s, buf);
}
+/* Tell the remote gdb that the process has exited due to SIG. */
+void gdb_signalled(CPUState *env, int sig)
+{
+ GDBState *s;
+ char buf[4];
+
+ s = gdbserver_state;
+ if (gdbserver_fd < 0 || s->fd < 0)
+ return;
+
+ snprintf(buf, sizeof(buf), "X%02x", target_signal_to_gdb (sig));
+ put_packet(s, buf);
+}
static void gdb_accept(void)
{
diff --git a/gdbstub.h b/gdbstub.h
index 4bfd872f3..c7d1c4b43 100644
--- a/gdbstub.h
+++ b/gdbstub.h
@@ -10,8 +10,10 @@ void gdb_do_syscall(gdb_syscall_complete_cb cb, const char *fmt, ...);
int use_gdb_syscalls(void);
void gdb_set_stop_cpu(CPUState *env);
#ifdef CONFIG_USER_ONLY
+int gdb_queuesig (void);
int gdb_handlesig (CPUState *, int);
void gdb_exit(CPUState *, int);
+void gdb_signalled(CPUState *, int);
int gdbserver_start(int);
void gdbserver_fork(CPUState *);
#else
diff --git a/linux-user/signal.c b/linux-user/signal.c
index e0f6aaf73..5e3052209 100644
--- a/linux-user/signal.c
+++ b/linux-user/signal.c
@@ -264,6 +264,26 @@ void target_to_host_siginfo(siginfo_t *info, const target_siginfo_t *tinfo)
(void *)(long)tswapl(tinfo->_sifields._rt._sigval.sival_ptr);
}
+static int fatal_signal (int sig)
+{
+ switch (sig) {
+ case TARGET_SIGCHLD:
+ case TARGET_SIGURG:
+ case TARGET_SIGWINCH:
+ /* Ignored by default. */
+ return 0;
+ case TARGET_SIGCONT:
+ case TARGET_SIGSTOP:
+ case TARGET_SIGTSTP:
+ case TARGET_SIGTTIN:
+ case TARGET_SIGTTOU:
+ /* Job control signals. */
+ return 0;
+ default:
+ return 1;
+ }
+}
+
void signal_init(void)
{
struct sigaction act;
@@ -298,10 +318,12 @@ void signal_init(void)
}
/* If there's already a handler installed then something has
gone horribly wrong, so don't even try to handle that case. */
- /* Install some handlers for our own use. */
- if (host_sig == SIGSEGV || host_sig == SIGBUS) {
+ /* Install some handlers for our own use. We need at least
+ SIGSEGV and SIGBUS, to detect exceptions. We can not just
+ trap all signals because it affects syscall interrupt
+ behavior. But do trap all default-fatal signals. */
+ if (fatal_signal (i))
sigaction(host_sig, &act, NULL);
- }
}
}
@@ -332,6 +354,7 @@ static void __attribute((noreturn)) force_sig(int sig)
fprintf(stderr, "qemu: uncaught target signal %d (%s) - exiting\n",
sig, strsignal(host_sig));
#if 1
+ gdb_signalled(thread_env, sig);
_exit(-host_sig);
#else
{
@@ -353,14 +376,16 @@ int queue_signal(CPUState *env, int sig, target_siginfo_t *info)
struct emulated_sigtable *k;
struct sigqueue *q, **pq;
abi_ulong handler;
+ int queue;
#if defined(DEBUG_SIGNAL)
fprintf(stderr, "queue_signal: sig=%d\n",
sig);
#endif
k = &ts->sigtab[sig - 1];
+ queue = gdb_queuesig ();
handler = sigact_table[sig - 1]._sa_handler;
- if (handler == TARGET_SIG_DFL) {
+ if (!queue && handler == TARGET_SIG_DFL) {
if (sig == TARGET_SIGTSTP || sig == TARGET_SIGTTIN || sig == TARGET_SIGTTOU) {
kill(getpid(),SIGSTOP);
return 0;
@@ -374,10 +399,10 @@ int queue_signal(CPUState *env, int sig, target_siginfo_t *info)
} else {
return 0; /* indicate ignored */
}
- } else if (handler == TARGET_SIG_IGN) {
+ } else if (!queue && handler == TARGET_SIG_IGN) {
/* ignore signal */
return 0;
- } else if (handler == TARGET_SIG_ERR) {
+ } else if (!queue && handler == TARGET_SIG_ERR) {
force_sig(sig);
} else {
pq = &k->first;
@@ -417,7 +442,8 @@ static void host_signal_handler(int host_signum, siginfo_t *info,
/* 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 ((host_signum == SIGSEGV || host_signum == SIGBUS)
+ && info->si_code == SI_KERNEL) {
if (cpu_signal_handler(host_signum, info, puc))
return;
}
@@ -544,7 +570,10 @@ int do_sigaction(int sig, const struct target_sigaction *act,
if (k->_sa_handler == TARGET_SIG_IGN) {
act1.sa_sigaction = (void *)SIG_IGN;
} else if (k->_sa_handler == TARGET_SIG_DFL) {
- act1.sa_sigaction = (void *)SIG_DFL;
+ if (fatal_signal (sig))
+ act1.sa_sigaction = host_signal_handler;
+ else
+ act1.sa_sigaction = (void *)SIG_DFL;
} else {
act1.sa_sigaction = host_signal_handler;
}
@@ -3107,17 +3136,21 @@ void process_pending_signals(CPUState *cpu_env)
sig = gdb_handlesig (cpu_env, sig);
if (!sig) {
- fprintf (stderr, "Lost signal\n");
- abort();
+ sa = NULL;
+ handler = TARGET_SIG_IGN;
+ } else {
+ sa = &sigact_table[sig - 1];
+ handler = sa->_sa_handler;
}
- sa = &sigact_table[sig - 1];
- handler = sa->_sa_handler;
if (handler == TARGET_SIG_DFL) {
- /* default handler : ignore some signal. The other are fatal */
- if (sig != TARGET_SIGCHLD &&
- sig != TARGET_SIGURG &&
- sig != TARGET_SIGWINCH) {
+ /* default handler : ignore some signal. The other are job control or fatal */
+ if (sig == TARGET_SIGTSTP || sig == TARGET_SIGTTIN || sig == TARGET_SIGTTOU) {
+ kill(getpid(),SIGSTOP);
+ } else if (sig != TARGET_SIGCHLD &&
+ sig != TARGET_SIGURG &&
+ sig != TARGET_SIGWINCH &&
+ sig != TARGET_SIGCONT) {
force_sig(sig);
}
} else if (handler == TARGET_SIG_IGN) {