need to thread the signal stack back to the previous stack, for

gdb and for _longjmp

SCCS-vsn: sys/sparc/sparc/machdep.c 7.3

diff --git a/usr/src/sys/sparc/sparc/machdep.c b/usr/src/sys/sparc/sparc/machdep.c
index e465168..5771984 100644 (file)
--- a/usr/src/sys/sparc/sparc/machdep.c
+++ b/usr/src/sys/sparc/sparc/machdep.c
@@ -13,9 +13,9 @@
  *
  * %sccs.include.redist.c%
  *
  *
  * %sccs.include.redist.c%
  *

- *     @(#)machdep.c   7.2 (Berkeley) %G%
+ *     @(#)machdep.c   7.3 (Berkeley) %G%

  *
  *

- * from: $Header: machdep.c,v 1.32 92/07/13 01:41:14 torek Exp $
+ * from: $Header: machdep.c,v 1.33 92/08/05 04:20:03 torek Exp $

  */
 
 #include "param.h"
  */
 
 #include "param.h"


@@ -325,12 +325,13 @@ sendsig(catcher, sig, mask, code)
        register struct sigacts *psp = p->p_sigacts;
        register struct sigframe *fp;
        register struct trapframe *tf;
        register struct sigacts *psp = p->p_sigacts;
        register struct sigframe *fp;
        register struct trapframe *tf;

-       register int addr, oonstack;
+       register int addr, oonstack, oldsp, newsp;

        struct sigframe sf;
        extern char sigcode[], esigcode[];
 #define        szsigcode       (esigcode - sigcode)
 
        tf = p->p_md.md_tf;
        struct sigframe sf;
        extern char sigcode[], esigcode[];
 #define        szsigcode       (esigcode - sigcode)
 
        tf = p->p_md.md_tf;

+       oldsp = tf->tf_out[6];

        oonstack = psp->ps_sigstk.ss_flags & SA_ONSTACK;
        /*
         * Compute new user stack addresses, subtract off
        oonstack = psp->ps_sigstk.ss_flags & SA_ONSTACK;
        /*
         * Compute new user stack addresses, subtract off


@@ -342,7 +343,7 @@ sendsig(catcher, sig, mask, code)
                                         psp->ps_sigstk.ss_size);
                psp->ps_sigstk.ss_flags |= SA_ONSTACK;
        } else
                                         psp->ps_sigstk.ss_size);
                psp->ps_sigstk.ss_flags |= SA_ONSTACK;
        } else

-               fp = (struct sigframe *)tf->tf_out[6];
+               fp = (struct sigframe *)oldsp;

        fp = (struct sigframe *)((int)(fp - 1) & ~7);
 
 #ifdef DEBUG
        fp = (struct sigframe *)((int)(fp - 1) & ~7);
 
 #ifdef DEBUG


@@ -367,7 +368,7 @@ sendsig(catcher, sig, mask, code)
         */
        sf.sf_sc.sc_onstack = oonstack;
        sf.sf_sc.sc_mask = mask;
         */
        sf.sf_sc.sc_onstack = oonstack;
        sf.sf_sc.sc_mask = mask;

-       sf.sf_sc.sc_sp = tf->tf_out[6];
+       sf.sf_sc.sc_sp = oldsp;

        sf.sf_sc.sc_pc = tf->tf_pc;
        sf.sf_sc.sc_npc = tf->tf_npc;
        sf.sf_sc.sc_psr = tf->tf_psr;
        sf.sf_sc.sc_pc = tf->tf_pc;
        sf.sf_sc.sc_npc = tf->tf_npc;
        sf.sf_sc.sc_psr = tf->tf_psr;


@@ -378,9 +379,15 @@ sendsig(catcher, sig, mask, code)
         * Put the stack in a consistent state before we whack away
         * at it.  Note that write_user_windows may just dump the
         * registers into the pcb; we need them in the process's memory.
         * Put the stack in a consistent state before we whack away
         * at it.  Note that write_user_windows may just dump the
         * registers into the pcb; we need them in the process's memory.

+        * We also need to make sure that when we start the signal handler,
+        * its %i6 (%fp), which is loaded from the newly allocated stack area,
+        * joins seamlessly with the frame it was in when the signal occurred,
+        * so that the debugger and _longjmp code can back up through it.

         */
         */

+       newsp = (int)fp - sizeof(struct rwindow);

        write_user_windows();
        write_user_windows();

-       if (rwindow_save(p) || copyout((caddr_t)&sf, (caddr_t)fp, sizeof sf)) {
+       if (rwindow_save(p) || copyout((caddr_t)&sf, (caddr_t)fp, sizeof sf) ||
+           suword(&((struct rwindow *)newsp)->rw_in[6], oldsp)) {

                /*
                 * Process has trashed its stack; give it an illegal
                 * instruction to halt it in its tracks.
                /*
                 * Process has trashed its stack; give it an illegal
                 * instruction to halt it in its tracks.


@@ -412,7 +419,7 @@ sendsig(catcher, sig, mask, code)
        }
        tf->tf_pc = addr;
        tf->tf_npc = addr + 4;
        }
        tf->tf_pc = addr;
        tf->tf_npc = addr + 4;

-       tf->tf_out[6] = (int)fp - sizeof(struct rwindow);
+       tf->tf_out[6] = newsp;

 #ifdef DEBUG
        if ((sigdebug & SDB_KSTACK) && p->p_pid == sigpid)
                printf("sendsig: about to return to catcher\n");
 #ifdef DEBUG
        if ((sigdebug & SDB_KSTACK) && p->p_pid == sigpid)
                printf("sendsig: about to return to catcher\n");