X-Git-Url: http://pilppa.org/gitweb/gitweb.cgi?a=blobdiff_plain;f=arch%2Fum%2Fos-Linux%2Fsignal.c;h=f11b3124a0c86cd22850e178e7c234fe20f9ad7e;hb=934a3595b30c986bab52bc9c08d12c8962c88c8a;hp=c1f46a0fef13d14c8740d80091fb18a2cf0690d7;hpb=94bc2be31a01a3055ec94176e595dfe208e92d3b;p=linux-2.6-omap-h63xx.git diff --git a/arch/um/os-Linux/signal.c b/arch/um/os-Linux/signal.c index c1f46a0fef1..f11b3124a0c 100644 --- a/arch/um/os-Linux/signal.c +++ b/arch/um/os-Linux/signal.c @@ -12,32 +12,66 @@ #include #include #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); @@ -47,6 +81,52 @@ void alarm_handler(ARCH_SIGHDLR_PARAM) 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) @@ -73,6 +153,7 @@ void set_handler(int sig, void (*handler)(int), int flags, ...) { struct sigaction action; va_list ap; + sigset_t sig_mask; int mask; va_start(ap, flags); @@ -85,7 +166,12 @@ void set_handler(int sig, void (*handler)(int), int 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) @@ -98,89 +184,77 @@ 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 + if(signals_enabled == 1) + return; -static int enable_mask(sigset_t *mask) -{ - int 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; - 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); + /* 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); }