Changeset 5298

Timestamp:

Oct 5, 2006, 1:46:06 PM (18 years ago)

Author:

Gary Byers

Message:

Save the mxcsr, load it with a C-like value (all exceptions masked)
before doing a callback. (Not doing this meant that tcr.foreign_mxcsr
was often set to a "lispy" value, where most exceptions were unmasked,
and this caused FP exceptions when calling out to foreign code with
the "lispy" tcr.foreign_mxcsr in effect.)

Mach exception stuff arranges to return via sigreturn. Didn't fix
the spurious SIGTRAPs, but might be the right idea (and might save
a context switch or two.)

Mach exception stuff initializes rflags to exception rflags when arranging
to resume thread at handler. Leaving them uninitialized was causing
spurious SIGTRAPs, since the trace bit(s) may have been set.

File:

• trunk/ccl/lisp-kernel/x86-exceptions.c (modified) (10 diffs)

trunk/ccl/lisp-kernel/x86-exceptions.c

@@ -372 +372 @@
 
 
+extern unsigned get_mxcsr();
+extern void set_mxcsr(unsigned);
   
 int
@@ -380 +382 @@
   natural  callback_ptr, i;
   int delta;
+  unsigned old_mxcsr = get_mxcsr();
+
+  set_mxcsr(0x1f80);
 
   /* Put the active stack pointers where .SPcallback expects them */
@@ -393 +398 @@
   delta = ((int (*)())callback_ptr) (xp, arg1, arg2, arg3, arg4, arg5);
   LOCK(lisp_global(EXCEPTION_LOCK), tcr);
+  set_mxcsr(old_mxcsr);
   return delta;
 }
@@ -832 +838 @@
 
 void
-signal_handler(int signum, siginfo_t *info, ExceptionInformation  *context, TCR *tcr)
+signal_handler(int signum, siginfo_t *info, ExceptionInformation  *context, TCR *tcr, int old_valence)
 {
 #ifdef DARWIN_GS_HACK
@@ -838 +844 @@
 #endif
   xframe_list xframe_link;
-  int old_valence;
 #ifndef DARWIN
   tcr = get_tcr(false);
@@ -857 +862 @@
   }
   unlock_exception_lock_in_handler(tcr);
-#ifndef DARWIN
   exit_signal_handler(tcr, old_valence);
-#endif
   /* raise_pending_interrupt(tcr); */
 #ifdef DARWIN_GS_HACK
@@ -866 +869 @@
   }
 #endif
-#ifndef DARWIN
   SIGRETURN(context);
-#endif
 }
 
 #ifdef DARWIN
-#endif
+void
+pseudo_signal_handler(int signum, siginfo_t *info, ExceptionInformation  *context, TCR *tcr, int old_valence)
+{
+  sigset_t mask;
+
+  sigfillset(&mask);
+
+  pthread_sigmask(SIG_SETMASK,&mask,&(context->uc_sigmask));
+  signal_handler(signum, info, context, tcr, old_valence);
+}
+#endif
+
+
 
 #ifdef LINUX
@@ -1886 +1899 @@
 #endif
   ExceptionInformation *pseudosigcontext;
-  int i, j;
+  int i, j, old_valence = tcr->valence;
   kern_return_t result;
   natural stackp, *stackpp;
@@ -1919 +1932 @@
   new_ts.__rdx = (natural)pseudosigcontext;
   new_ts.__rcx = (natural)tcr;
+  new_ts.__r8 = (natural)old_valence;
   new_ts.__rsp = stackp;
+  new_ts.__rflags = ts->__rflags;
 
 
@@ -2053 +2068 @@
       if (signum) {
         kret = setup_signal_frame(thread,
-                                  (void *)signal_handler,
+                                  (void *)pseudo_signal_handler,
                                   signum,
                                   code,