#include <signal.h>
#include <strings.h>
#include "as-layout.h"
-#include "kern_constants.h"
#include "kern_util.h"
#include "os.h"
#include "sysdep/barrier.h"
#include "sysdep/sigcontext.h"
-#include "task.h"
#include "user.h"
+/* Copied from linux/compiler-gcc.h since we can't include it directly */
+#define barrier() __asm__ __volatile__("": : :"memory")
+
void (*sig_info[NSIG])(int, struct uml_pt_regs *) = {
[SIGTRAP] = relay_signal,
[SIGFPE] = relay_signal,
[SIGIO] = sigio_handler,
[SIGVTALRM] = timer_handler };
-static struct uml_pt_regs ksig_regs[UM_NR_CPUS];
-
-void sig_handler_common_skas(int sig, void *sc_ptr)
+static void sig_handler_common(int sig, struct sigcontext *sc)
{
- struct sigcontext *sc = sc_ptr;
- struct uml_pt_regs *r;
- void (*handler)(int, struct uml_pt_regs *);
- int save_user, save_errno = errno;
+ struct uml_pt_regs r;
+ int save_errno = errno;
- /*
- * This is done because to allow SIGSEGV to be delivered inside a SEGV
- * handler. This can happen in copy_user, and if SEGV is disabled,
- * the process will die.
- * XXX Figure out why this is better than SA_NODEFER
- */
+ r.is_user = 0;
if (sig == SIGSEGV) {
- change_sig(SIGSEGV, 1);
- /*
- * For segfaults, we want the data from the
- * sigcontext. In this case, we don't want to mangle
- * the process registers, so use a static set of
- * registers. For other signals, the process
- * registers are OK.
- */
- r = &ksig_regs[cpu()];
- copy_sc(r, sc_ptr);
- } else
- r = TASK_REGS(get_current());
-
- save_user = r->is_user;
- r->is_user = 0;
- if ((sig == SIGFPE) || (sig == SIGSEGV) || (sig == SIGBUS) ||
- (sig == SIGILL) || (sig == SIGTRAP))
- GET_FAULTINFO_FROM_SC(r->faultinfo, sc);
-
- change_sig(SIGUSR1, 1);
-
- handler = sig_info[sig];
+ /* For segfaults, we want the data from the sigcontext. */
+ copy_sc(&r, sc);
+ GET_FAULTINFO_FROM_SC(r.faultinfo, sc);
+ }
- /* unblock SIGVTALRM, SIGIO if sig isn't IRQ signal */
+ /* enable signals if sig isn't IRQ signal */
if ((sig != SIGIO) && (sig != SIGWINCH) && (sig != SIGVTALRM))
unblock_signals();
- handler(sig, r);
+ (*sig_info[sig])(sig, &r);
errno = save_errno;
- r->is_user = save_user;
}
-/* Copied from linux/compiler-gcc.h since we can't include it directly */
-#define barrier() __asm__ __volatile__("": : :"memory")
-
/*
* These are the asynchronous signals. SIGPROF is excluded because we want to
* be able to profile all of UML, not just the non-critical sections. If
#define SIGVTALRM_MASK (1 << SIGVTALRM_BIT)
static int signals_enabled;
-static unsigned int pending;
+static unsigned int signals_pending;
void sig_handler(int sig, struct sigcontext *sc)
{
enabled = signals_enabled;
if (!enabled && (sig == SIGIO)) {
- pending |= SIGIO_MASK;
+ signals_pending |= SIGIO_MASK;
return;
}
block_signals();
- sig_handler_common_skas(sig, sc);
+ sig_handler_common(sig, sc);
set_signals(enabled);
}
enabled = signals_enabled;
if (!signals_enabled) {
- pending |= SIGVTALRM_MASK;
+ signals_pending |= SIGVTALRM_MASK;
return;
}
panic("enabling signal stack failed, errno = %d\n", errno);
}
-void remove_sigstack(void)
-{
- stack_t stack = ((stack_t) { .ss_flags = SS_DISABLE,
- .ss_sp = NULL,
- .ss_size = 0 });
-
- if (sigaltstack(&stack, NULL) != 0)
- panic("disabling signal stack failed, errno = %d\n", errno);
-}
-
void (*handlers[_NSIG])(int sig, struct sigcontext *sc);
void handle_signal(int sig, struct sigcontext *sc)
sigaddset(&action.sa_mask, mask);
va_end(ap);
+ if (sig == SIGSEGV)
+ flags |= SA_NODEFER;
+
action.sa_flags = flags;
action.sa_restorer = NULL;
if (sigaction(sig, &action, NULL) < 0)
int change_sig(int signal, int on)
{
- sigset_t sigset, old;
+ sigset_t sigset;
sigemptyset(&sigset);
sigaddset(&sigset, signal);
- if (sigprocmask(on ? SIG_UNBLOCK : SIG_BLOCK, &sigset, &old) < 0)
+ if (sigprocmask(on ? SIG_UNBLOCK : SIG_BLOCK, &sigset, NULL) < 0)
return -errno;
- return !sigismember(&old, signal);
+
+ return 0;
}
void block_signals(void)
/*
* 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.
+ * recheck signals_pending.
*/
- while(1) {
+ while (1) {
/*
* Save and reset save_pending after enabling signals. This
- * way, pending won't be changed while we're reading it.
+ * way, signals_pending won't be changed while we're reading it.
*/
signals_enabled = 1;
/*
- * Setting signals_enabled and reading pending must
+ * Setting signals_enabled and reading signals_pending must
* happen in this order.
*/
barrier();
- save_pending = pending;
+ save_pending = signals_pending;
if (save_pending == 0)
return;
- pending = 0;
+ signals_pending = 0;
/*
* We have pending interrupts, so disable signals, as the
* back here.
*/
if (save_pending & SIGIO_MASK)
- sig_handler_common_skas(SIGIO, NULL);
+ sig_handler_common(SIGIO, NULL);
if (save_pending & SIGVTALRM_MASK)
real_alarm_handler(NULL);
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff