diff options
Diffstat (limited to 'bsd-user')
-rw-r--r-- | bsd-user/qemu.h | 7 | ||||
-rw-r--r-- | bsd-user/signal.c | 67 |
2 files changed, 74 insertions, 0 deletions
diff --git a/bsd-user/qemu.h b/bsd-user/qemu.h index 99c37fc994..49f01932a5 100644 --- a/bsd-user/qemu.h +++ b/bsd-user/qemu.h @@ -94,6 +94,13 @@ typedef struct TaskState { * from multiple threads.) */ int signal_pending; + /* + * This thread's signal mask, as requested by the guest program. + * The actual signal mask of this thread may differ: + * + we don't let SIGSEGV and SIGBUS be blocked while running guest code + * + sometimes we block all signals to avoid races + */ + sigset_t signal_mask; uint8_t stack[]; } __attribute__((aligned(16))) TaskState; diff --git a/bsd-user/signal.c b/bsd-user/signal.c index 1313baec96..3ef7cf5e23 100644 --- a/bsd-user/signal.c +++ b/bsd-user/signal.c @@ -28,6 +28,9 @@ * fork. */ +static struct target_sigaction sigact_table[TARGET_NSIG]; +static void host_signal_handler(int host_sig, siginfo_t *info, void *puc); + /* * The BSD ABIs use the same singal numbers across all the CPU architectures, so * (unlike Linux) these functions are just the identity mapping. This might not @@ -52,6 +55,28 @@ void queue_signal(CPUArchState *env, int sig, target_siginfo_t *info) qemu_log_mask(LOG_UNIMP, "No signal queueing, dropping signal %d\n", sig); } +static int fatal_signal(int sig) +{ + + switch (sig) { + case TARGET_SIGCHLD: + case TARGET_SIGURG: + case TARGET_SIGWINCH: + case TARGET_SIGINFO: + /* 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; + } +} + /* * Force a synchronously taken QEMU_SI_FAULT signal. For QEMU the * 'force' part is handled in process_pending_signals(). @@ -69,8 +94,50 @@ void force_sig_fault(int sig, int code, abi_ulong addr) queue_signal(env, sig, &info); } +static void host_signal_handler(int host_sig, siginfo_t *info, void *puc) +{ +} + void signal_init(void) { + TaskState *ts = (TaskState *)thread_cpu->opaque; + struct sigaction act; + struct sigaction oact; + int i; + int host_sig; + + /* Set the signal mask from the host mask. */ + sigprocmask(0, 0, &ts->signal_mask); + + sigfillset(&act.sa_mask); + act.sa_sigaction = host_signal_handler; + act.sa_flags = SA_SIGINFO; + + for (i = 1; i <= TARGET_NSIG; i++) { +#ifdef CONFIG_GPROF + if (i == TARGET_SIGPROF) { + continue; + } +#endif + host_sig = target_to_host_signal(i); + sigaction(host_sig, NULL, &oact); + if (oact.sa_sigaction == (void *)SIG_IGN) { + sigact_table[i - 1]._sa_handler = TARGET_SIG_IGN; + } else if (oact.sa_sigaction == (void *)SIG_DFL) { + sigact_table[i - 1]._sa_handler = TARGET_SIG_DFL; + } + /* + * 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. 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); + } + } } void process_pending_signals(CPUArchState *cpu_env) |