#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);
}
extern void do_boot_timer_handler(struct sigcontext * sc);
void boot_timer_handler(ARCH_SIGHDLR_PARAM)
{
struct sigcontext *sc;
+ int enabled;
ARCH_GET_SIGCONTEXT(sc, sig);
+ enabled = signals_enabled;
+ if(!enabled){
+ if(sig == SIGVTALRM)
+ pending |= SIGVTALRM_MASK;
+ else pending |= SIGALRM_MASK;
+ return;
+ }
+
+ block_signals();
+
do_boot_timer_handler(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);
-}
+ int save_pending;
-/* 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
-
-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);
- }
-
- /* 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");
+ ret = signals_enabled;
+ if(enable)
+ unblock_signals();
+ else block_signals();
- return(ret);
+ return ret;
}
void os_usr1_signal(int on)
#include "mem.h"
#include "uml-config.h"
#include "process.h"
+#include "longjmp.h"
int is_skas_winch(int pid, int fd, void *data)
{
{
unsigned long flags;
sigjmp_buf switch_buf, fork_buf;
+ int enable;
*switch_buf_ptr = &switch_buf;
*fork_buf_ptr = &fork_buf;
*/
flags = get_signals();
block_signals();
- if(sigsetjmp(fork_buf, 1) == 0)
+ if(UML_SIGSETJMP(&fork_buf, enable) == 0)
new_thread_proc(stack, handler);
remove_sigstack();
void thread_wait(void *sw, void *fb)
{
sigjmp_buf buf, **switch_buf = sw, *fork_buf;
+ int enable;
*switch_buf = &buf;
fork_buf = fb;
- if(sigsetjmp(buf, 1) == 0)
+ if(UML_SIGSETJMP(&buf, enable) == 0)
siglongjmp(*fork_buf, INIT_JMP_REMOVE_SIGSTACK);
}
void switch_threads(void *me, void *next)
{
sigjmp_buf my_buf, **me_ptr = me, *next_buf = next;
+ int enable;
*me_ptr = &my_buf;
- if(sigsetjmp(my_buf, 1) == 0)
- siglongjmp(*next_buf, 1);
+ if(UML_SIGSETJMP(&my_buf, enable) == 0)
+ UML_SIGLONGJMP(next_buf, 1);
}
static sigjmp_buf initial_jmpbuf;
int start_idle_thread(void *stack, void *switch_buf_ptr, void **fork_buf_ptr)
{
sigjmp_buf **switch_buf = switch_buf_ptr;
- int n;
+ int n, enable;
set_handler(SIGWINCH, (__sighandler_t) sig_handler,
SA_ONSTACK | SA_RESTART, SIGUSR1, SIGIO, SIGALRM,
SIGVTALRM, -1);
*fork_buf_ptr = &initial_jmpbuf;
- n = sigsetjmp(initial_jmpbuf, 1);
+ n = UML_SIGSETJMP(&initial_jmpbuf, enable);
switch(n){
case INIT_JMP_NEW_THREAD:
new_thread_proc((void *) stack, new_thread_handler);
break;
case INIT_JMP_CALLBACK:
(*cb_proc)(cb_arg);
- siglongjmp(*cb_back, 1);
+ UML_SIGLONGJMP(cb_back, 1);
break;
case INIT_JMP_HALT:
kmalloc_ok = 0;
default:
panic("Bad sigsetjmp return in start_idle_thread - %d\n", n);
}
- siglongjmp(**switch_buf, 1);
+ UML_SIGLONGJMP(*switch_buf, 1);
}
void initial_thread_cb_skas(void (*proc)(void *), void *arg)
{
sigjmp_buf here;
+ int enable;
cb_proc = proc;
cb_arg = arg;
cb_back = &here;
block_signals();
- if(sigsetjmp(here, 1) == 0)
- siglongjmp(initial_jmpbuf, INIT_JMP_CALLBACK);
+ if(UML_SIGSETJMP(&here, enable) == 0)
+ UML_SIGLONGJMP(&initial_jmpbuf, INIT_JMP_CALLBACK);
unblock_signals();
cb_proc = NULL;
void halt_skas(void)
{
block_signals();
- siglongjmp(initial_jmpbuf, INIT_JMP_HALT);
+ UML_SIGLONGJMP(&initial_jmpbuf, INIT_JMP_HALT);
}
void reboot_skas(void)
{
block_signals();
- siglongjmp(initial_jmpbuf, INIT_JMP_REBOOT);
+ UML_SIGLONGJMP(&initial_jmpbuf, INIT_JMP_REBOOT);
}
void switch_mm_skas(struct mm_id *mm_idp)
projects / mirror_ubuntu-hirsute-kernel.git / commitdiff