[Git][cmucl/cmucl][sparc64-dev-nyi] Correct the implementation of the not-implmeented handler.

[Raymond Toy]

Raymond Toy pushed to branch sparc64-dev-nyi at cmucl / cmucl


Commits:
06617844 by Raymond Toy at 2017-01-18T20:53:28-08:00
Correct the implementation of the not-implmeented handler.

The location of the string was off by one word and the length was
incorrectly calculated because we have a 19-bit word displacement for
the ba,pt instruction.

- - - - -


1 changed file:

- src/lisp/sparc-arch.c


Changes:

=====================================
src/lisp/sparc-arch.c
=====================================
--- a/src/lisp/sparc-arch.c
+++ b/src/lisp/sparc-arch.c
@@ -522,12 +522,19 @@ sigill_handler(HANDLER_ARGS)
 
               /*
                * Compute the maximum length of the string from the
-               * offset in the branch instruction.  (The signed offset
-               * is in the low 22 bits of the instruction.) Then try
-               * to find the last nul character for end of the string.
+               * offset in the branch instruction.  This code assumes
+               * a ba,pt instruction which has a 19-bit word offset in
+               * the low part of the instruction.  Because branches
+               * have a delay slot, the string starts two words past
+               * the branch instruction.
                */
-              string = (unsigned char *) &pc[2];
-              length = (pc[1] & 0x3fffff);
+              string = (unsigned char *) &pc[3];
+              /*
+               * The offset is in 32-bit words, so subtract one for
+               * the instruction in the branch delay slot and scale up
+               * the offet to be in bytes.
+               */
+              length = 4 * ((pc[1] & 0x7FFFF) - 1);
 
               while (string[length - 1] == '\0') {
                   --length;
@@ -538,14 +545,14 @@ sigill_handler(HANDLER_ARGS)
                * don't actually want to abort.  We want to continue,
                * but print out a useful message.
                */
-              printf("NOT-IMPLEMENTED: %p: \"%.*s\"\n", pc, length, (char*)(pc + 2));
+              printf("NOT-IMPLEMENTED: %p: \"%.*s\"\n", pc, length, string);
 
               /*
-               * Skip over the UDF instruction so if we can
+               * Skip over the illtrap instruction so if we can
                * continue.  This will execute the branch, skipping
                * over the string too.
                */
-              SC_PC(context) = (unsigned long) (pc + 1);
+              SC_PC(os_context) = (unsigned long) (pc + 1);
               
           }
           break;



View it on GitLab: https://gitlab.common-lisp.net/cmucl/cmucl/commit/0661784461fda653dfb2fc155c6e7cf89e46fbbc
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://mailman.common-lisp.net/pipermail/cmucl-cvs/attachments/20170119/44a23d54/attachment-0001.html>