1 files changed, 18 insertions, 45 deletions

diff --git a/arch/um/os-Linux/signal.c b/arch/um/os-Linux/signal.c
index cde9e766b5b4..91a35da5fe90 100644
--- a/arch/um/os-Linux/signal.c
+++ b/arch/um/os-Linux/signal.c
@@ -10,14 +10,15 @@
 #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,
@@ -28,58 +29,27 @@ void (*sig_info[NSIG])(int, struct uml_pt_regs *) = {
         [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
@@ -107,7 +77,7 @@ void sig_handler(int sig, struct sigcontext *sc)
 
         block_signals();
 
-        sig_handler_common_skas(sig, sc);
+        sig_handler_common(sig, sc);
 
         set_signals(enabled);
 }
@@ -227,6 +197,9 @@ void set_handler(int sig, void (*handler)(int), int flags, ...)
                 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)
@@ -306,7 +279,7 @@ void unblock_signals(void)
                  * 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);