#include <string.h>
#include <sys/mman.h>
#include "user_util.h"
-#include "kern_util.h"
#include "user.h"
#include "signal_kern.h"
#include "sysdep/sigcontext.h"
#include "sysdep/signal.h"
#include "sigcontext.h"
-#include "time_user.h"
#include "mode.h"
+#include "os.h"
+
+/* These are the asynchronous signals. SIGVTALRM and SIGARLM are handled
+ * together under SIGVTALRM_BIT. SIGPROF is excluded because we want to
+ * be able to profile all of UML, not just the non-critical sections. If
+ * profiling is not thread-safe, then that is not my problem. We can disable
+ * profiling when SMP is enabled in that case.
+ */
+#define SIGIO_BIT 0
+#define SIGIO_MASK (1 << SIGIO_BIT)
+
+#define SIGVTALRM_BIT 1
+#define SIGVTALRM_MASK (1 << SIGVTALRM_BIT)
+
+#define SIGALRM_BIT 2
+#define SIGALRM_MASK (1 << SIGALRM_BIT)
+
+static int signals_enabled = 1;
+static int pending = 0;
void sig_handler(ARCH_SIGHDLR_PARAM)
{
struct sigcontext *sc;
+ int enabled;
+
+ /* Must be the first thing that this handler does - x86_64 stores
+ * the sigcontext in %rdx, and we need to save it before it has a
+ * chance to get trashed.
+ */
ARCH_GET_SIGCONTEXT(sc, sig);
+
+ enabled = signals_enabled;
+ if(!enabled && (sig == SIGIO)){
+ pending |= SIGIO_MASK;
+ return;
+ }
+
+ block_signals();
+
CHOOSE_MODE_PROC(sig_handler_common_tt, sig_handler_common_skas,
sig, sc);
+
+ set_signals(enabled);
}
extern int timer_irq_inited;
-void alarm_handler(ARCH_SIGHDLR_PARAM)
+static void real_alarm_handler(int sig, struct sigcontext *sc)
{
- struct sigcontext *sc;
-
- ARCH_GET_SIGCONTEXT(sc, sig);
- if(!timer_irq_inited) return;
+ if(!timer_irq_inited){
+ signals_enabled = 1;
+ return;
+ }
if(sig == SIGALRM)
switch_timers(0);
if(sig == SIGALRM)
switch_timers(1);
+
+}
+
+void alarm_handler(ARCH_SIGHDLR_PARAM)
+{
+ struct sigcontext *sc;
+ int enabled;
+
+ ARCH_GET_SIGCONTEXT(sc, sig);
+
+ enabled = signals_enabled;
+ if(!signals_enabled){
+ if(sig == SIGVTALRM)
+ pending |= SIGVTALRM_MASK;
+ else pending |= SIGALRM_MASK;
+
+ return;
+ }
+
+ block_signals();
+
+ real_alarm_handler(sig, sc);
+ set_signals(enabled);
}
void set_sigstack(void *sig_stack, int size)
{
struct sigaction action;
va_list ap;
+ sigset_t sig_mask;
int mask;
va_start(ap, flags);
action.sa_flags = flags;
action.sa_restorer = NULL;
if(sigaction(sig, &action, NULL) < 0)
- panic("sigaction failed");
+ panic("sigaction failed - errno = %d\n", errno);
+
+ sigemptyset(&sig_mask);
+ sigaddset(&sig_mask, sig);
+ if(sigprocmask(SIG_UNBLOCK, &sig_mask, NULL) < 0)
+ panic("sigprocmask failed - errno = %d\n", errno);
}
int change_sig(int signal, int on)
return(!sigismember(&old, signal));
}
-/* Both here and in set/get_signal we don't touch SIGPROF, because we must not
- * disable profiling; it's safe because the profiling code does not interact
- * with the kernel code at all.*/
-
-static void change_signals(int type)
-{
- sigset_t mask;
-
- sigemptyset(&mask);
- sigaddset(&mask, SIGVTALRM);
- sigaddset(&mask, SIGALRM);
- sigaddset(&mask, SIGIO);
- if(sigprocmask(type, &mask, NULL) < 0)
- panic("Failed to change signal mask - errno = %d", errno);
-}
-
void block_signals(void)
{
- change_signals(SIG_BLOCK);
+ signals_enabled = 0;
}
void unblock_signals(void)
{
- change_signals(SIG_UNBLOCK);
-}
-
-/* These are the asynchronous signals. SIGVTALRM and SIGARLM are handled
- * together under SIGVTALRM_BIT. SIGPROF is excluded because we want to
- * be able to profile all of UML, not just the non-critical sections. If
- * profiling is not thread-safe, then that is not my problem. We can disable
- * profiling when SMP is enabled in that case.
- */
-#define SIGIO_BIT 0
-#define SIGVTALRM_BIT 1
+ int save_pending;
-static int enable_mask(sigset_t *mask)
-{
- int sigs;
+ if(signals_enabled == 1)
+ return;
- sigs = sigismember(mask, SIGIO) ? 0 : 1 << SIGIO_BIT;
- sigs |= sigismember(mask, SIGVTALRM) ? 0 : 1 << SIGVTALRM_BIT;
- sigs |= sigismember(mask, SIGALRM) ? 0 : 1 << SIGVTALRM_BIT;
- return(sigs);
+ /* We loop because the IRQ handler returns with interrupts off. So,
+ * interrupts may have arrived and we need to re-enable them and
+ * recheck pending.
+ */
+ while(1){
+ /* Save and reset save_pending after enabling signals. This
+ * way, pending won't be changed while we're reading it.
+ */
+ signals_enabled = 1;
+
+ save_pending = pending;
+ if(save_pending == 0)
+ return;
+
+ pending = 0;
+
+ /* We have pending interrupts, so disable signals, as the
+ * handlers expect them off when they are called. They will
+ * be enabled again above.
+ */
+
+ signals_enabled = 0;
+
+ /* Deal with SIGIO first because the alarm handler might
+ * schedule, leaving the pending SIGIO stranded until we come
+ * back here.
+ */
+ if(save_pending & SIGIO_MASK)
+ CHOOSE_MODE_PROC(sig_handler_common_tt,
+ sig_handler_common_skas, SIGIO, NULL);
+
+ if(save_pending & SIGALRM_MASK)
+ real_alarm_handler(SIGALRM, NULL);
+
+ if(save_pending & SIGVTALRM_MASK)
+ real_alarm_handler(SIGVTALRM, NULL);
+ }
}
int get_signals(void)
{
- sigset_t mask;
-
- if(sigprocmask(SIG_SETMASK, NULL, &mask) < 0)
- panic("Failed to get signal mask");
- return(enable_mask(&mask));
+ return signals_enabled;
}
int set_signals(int enable)
{
- sigset_t mask;
int ret;
+ if(signals_enabled == enable)
+ return enable;
- sigemptyset(&mask);
- if(enable & (1 << SIGIO_BIT))
- sigaddset(&mask, SIGIO);
- if(enable & (1 << SIGVTALRM_BIT)){
- sigaddset(&mask, SIGVTALRM);
- sigaddset(&mask, SIGALRM);
- }
+ ret = signals_enabled;
+ if(enable)
+ unblock_signals();
+ else block_signals();
- /* This is safe - sigprocmask is guaranteed to copy locally the
- * value of new_set, do his work and then, at the end, write to
- * old_set.
- */
- if(sigprocmask(SIG_UNBLOCK, &mask, &mask) < 0)
- panic("Failed to enable signals");
- ret = enable_mask(&mask);
- sigemptyset(&mask);
- if((enable & (1 << SIGIO_BIT)) == 0)
- sigaddset(&mask, SIGIO);
- if((enable & (1 << SIGVTALRM_BIT)) == 0){
- sigaddset(&mask, SIGVTALRM);
- sigaddset(&mask, SIGALRM);
- }
- if(sigprocmask(SIG_BLOCK, &mask, NULL) < 0)
- panic("Failed to block signals");
+ return ret;
+}
- return(ret);
+void os_usr1_signal(int on)
+{
+ change_sig(SIGUSR1, on);
}
git.openpandora.org / pandora-kernel.git / blobdiff