@@ -17,6 +17,7 @@
* along with this program; if not, see <http://www.gnu.org/licenses/>.
*/
#include "qemu/osdep.h"
+#include "qemu/bitops.h"
#include <sys/ucontext.h>
#include <sys/resource.h>
@@ -274,70 +275,129 @@ static inline void host_to_target_siginfo_noswap(target_siginfo_t *tinfo,
const siginfo_t *info)
{
int sig = host_to_target_signal(info->si_signo);
+ int si_code = info->si_code;
+ int si_type;
tinfo->si_signo = sig;
tinfo->si_errno = 0;
tinfo->si_code = info->si_code;
- if (sig == TARGET_SIGILL || sig == TARGET_SIGFPE || sig == TARGET_SIGSEGV
- || sig == TARGET_SIGBUS || sig == TARGET_SIGTRAP) {
- /* Should never come here, but who knows. The information for
- the target is irrelevant. */
- tinfo->_sifields._sigfault._addr = 0;
- } else if (sig == TARGET_SIGIO) {
- tinfo->_sifields._sigpoll._band = info->si_band;
- tinfo->_sifields._sigpoll._fd = info->si_fd;
- } else if (sig == TARGET_SIGCHLD) {
- tinfo->_sifields._sigchld._pid = info->si_pid;
- tinfo->_sifields._sigchld._uid = info->si_uid;
- tinfo->_sifields._sigchld._status
+ /* This is awkward, 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() will strip these top bits out before writing
+ * si_code to the guest (sign-extending the lower bits).
+ */
+
+ switch (si_code) {
+ case SI_USER:
+ case SI_TKILL:
+ case SI_KERNEL:
+ /* Sent via kill(), tkill() or tgkill(), or direct from the kernel.
+ * These are the only unspoofable si_code values.
+ */
+ tinfo->_sifields._kill._pid = info->si_pid;
+ tinfo->_sifields._kill._uid = info->si_uid;
+ si_type = QEMU_SI_KILL;
+ break;
+ default:
+ /* Everything else is spoofable. Make best guess based on signal */
+ switch (sig) {
+ case TARGET_SIGCHLD:
+ tinfo->_sifields._sigchld._pid = info->si_pid;
+ tinfo->_sifields._sigchld._uid = info->si_uid;
+ tinfo->_sifields._sigchld._status
= host_to_target_waitstatus(info->si_status);
- tinfo->_sifields._sigchld._utime = info->si_utime;
- tinfo->_sifields._sigchld._stime = info->si_stime;
- } 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
+ tinfo->_sifields._sigchld._utime = info->si_utime;
+ tinfo->_sifields._sigchld._stime = info->si_stime;
+ si_type = QEMU_SI_CHLD;
+ break;
+ case TARGET_SIGIO:
+ tinfo->_sifields._sigpoll._band = info->si_band;
+ tinfo->_sifields._sigpoll._fd = info->si_fd;
+ si_type = QEMU_SI_POLL;
+ break;
+ default:
+ /* Assume a sigqueue()/mq_notify()/rt_sigqueueinfo() source. */
+ 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
= (abi_ulong)(unsigned long)info->si_value.sival_ptr;
+ si_type = QEMU_SI_RT;
+ break;
+ }
+ break;
}
+
+ tinfo->si_code = deposit32(si_code, 16, 16, si_type);
}
static void tswap_siginfo(target_siginfo_t *tinfo,
const target_siginfo_t *info)
{
- int 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 == TARGET_SIGILL || sig == TARGET_SIGFPE || sig == TARGET_SIGSEGV
- || sig == TARGET_SIGBUS || sig == TARGET_SIGTRAP) {
- tinfo->_sifields._sigfault._addr
- = tswapal(info->_sifields._sigfault._addr);
- } else if (sig == TARGET_SIGIO) {
- tinfo->_sifields._sigpoll._band
- = tswap32(info->_sifields._sigpoll._band);
- tinfo->_sifields._sigpoll._fd = tswap32(info->_sifields._sigpoll._fd);
- } else if (sig == TARGET_SIGCHLD) {
- tinfo->_sifields._sigchld._pid
- = tswap32(info->_sifields._sigchld._pid);
- tinfo->_sifields._sigchld._uid
- = tswap32(info->_sifields._sigchld._uid);
- tinfo->_sifields._sigchld._status
- = tswap32(info->_sifields._sigchld._status);
- tinfo->_sifields._sigchld._utime
- = tswapal(info->_sifields._sigchld._utime);
- tinfo->_sifields._sigchld._stime
- = tswapal(info->_sifields._sigchld._stime);
- } 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
- = tswapal(info->_sifields._rt._sigval.sival_ptr);
+ int si_type = extract32(info->si_code, 16, 16);
+ int si_code = sextract32(info->si_code, 0, 16);
+
+ __put_user(info->si_signo, &tinfo->si_signo);
+ __put_user(info->si_errno, &tinfo->si_errno);
+ __put_user(si_code, &tinfo->si_code);
+
+ /* We can use our internal marker of which fields in the structure
+ * are valid, rather than duplicating the guesswork of
+ * host_to_target_siginfo_noswap() here.
+ */
+ switch (si_type) {
+ case QEMU_SI_KILL:
+ __put_user(info->_sifields._kill._pid, &tinfo->_sifields._kill._pid);
+ __put_user(info->_sifields._kill._uid, &tinfo->_sifields._kill._uid);
+ break;
+ case QEMU_SI_TIMER:
+ __put_user(info->_sifields._timer._timer1,
+ &tinfo->_sifields._timer._timer1);
+ __put_user(info->_sifields._timer._timer2,
+ &tinfo->_sifields._timer._timer2);
+ break;
+ case QEMU_SI_POLL:
+ __put_user(info->_sifields._sigpoll._band,
+ &tinfo->_sifields._sigpoll._band);
+ __put_user(info->_sifields._sigpoll._fd,
+ &tinfo->_sifields._sigpoll._fd);
+ break;
+ case QEMU_SI_FAULT:
+ __put_user(info->_sifields._sigfault._addr,
+ &tinfo->_sifields._sigfault._addr);
+ break;
+ case QEMU_SI_CHLD:
+ __put_user(info->_sifields._sigchld._pid,
+ &tinfo->_sifields._sigchld._pid);
+ __put_user(info->_sifields._sigchld._uid,
+ &tinfo->_sifields._sigchld._uid);
+ __put_user(info->_sifields._sigchld._status,
+ &tinfo->_sifields._sigchld._status);
+ __put_user(info->_sifields._sigchld._utime,
+ &tinfo->_sifields._sigchld._utime);
+ __put_user(info->_sifields._sigchld._stime,
+ &tinfo->_sifields._sigchld._stime);
+ break;
+ case QEMU_SI_RT:
+ __put_user(info->_sifields._rt._pid, &tinfo->_sifields._rt._pid);
+ __put_user(info->_sifields._rt._uid, &tinfo->_sifields._rt._uid);
+ __put_user(info->_sifields._rt._sigval.sival_ptr,
+ &tinfo->_sifields._rt._sigval.sival_ptr);
+ break;
+ default:
+ g_assert_not_reached();
}
}
-
void host_to_target_siginfo(target_siginfo_t *tinfo, const siginfo_t *info)
{
host_to_target_siginfo_noswap(tinfo, info);
@@ -505,6 +565,13 @@ int queue_signal(CPUArchState *env, int sig, target_siginfo_t *info)
trace_user_queue_signal(env, sig);
+ /* Currently all callers define siginfo structures which
+ * use the _sifields._sigfault union member, so we can
+ * set the type here. If that changes we should push this
+ * out so the si_type is passed in by callers.
+ */
+ info->si_code = deposit32(info->si_code, 16, 16, QEMU_SI_FAULT);
+
ts->sync_signal.info = *info;
ts->sync_signal.pending = sig;
/* signal that a new signal is pending */
@@ -673,6 +673,21 @@ typedef struct {
#define TARGET_SI_PAD_SIZE ((TARGET_SI_MAX_SIZE - TARGET_SI_PREAMBLE_SIZE) / sizeof(int))
+/* Within QEMU the top 16 bits of si_code indicate which of the parts of
+ * the union in target_siginfo is valid. This only applies between
+ * host_to_target_siginfo_noswap() and tswap_siginfo(); it does not
+ * appear either within host siginfo_t or in target_siginfo structures
+ * which we get from the guest userspace program. (The Linux kernel
+ * does a similar thing with using the top bits for its own internal
+ * purposes but not letting them be visible to userspace.)
+ */
+#define QEMU_SI_KILL 0
+#define QEMU_SI_TIMER 1
+#define QEMU_SI_POLL 2
+#define QEMU_SI_FAULT 3
+#define QEMU_SI_CHLD 4
+#define QEMU_SI_RT 5
+
typedef struct target_siginfo {
#ifdef TARGET_MIPS
int si_signo;