xnu-2782.1.97.tar.gz

[apple/xnu.git] / bsd / dev / i386 / dtrace_subr_x86.c

diff --git a/bsd/dev/i386/dtrace_subr_x86.c b/bsd/dev/i386/dtrace_subr_x86.c
index ae29f84167051eda1f59844bfe617a4bb40fe2b3..c4ab38a31351d5240098e758f6861597a84db9f8 100644 (file)
--- a/bsd/dev/i386/dtrace_subr_x86.c
+++ b/bsd/dev/i386/dtrace_subr_x86.c
@@ -20,12 +20,12 @@
  */
 
 /*
- * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
+ * Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
  * Use is subject to license terms.
  */
 
 /*
- * #pragma ident       "@(#)dtrace_subr.c      1.13    06/06/12 SMI"
+ * #pragma ident       "@(#)dtrace_subr.c      1.16    07/09/18 SMI"
  */
 
 #include <sys/dtrace.h>
@@ -154,7 +154,7 @@ dtrace_user_probe(x86_saved_state_t *regs)
 
                return KERN_SUCCESS;
        } else if (trapno == T_INT3) {
-               uint8_t instr;
+               uint8_t instr, instr2;
                rwp = &CPU->cpu_ft_lock;
 
                /*
@@ -189,7 +189,8 @@ dtrace_user_probe(x86_saved_state_t *regs)
                 * that case, return to user land to retry the instuction.
                 */
                user_addr_t pc = (regs64) ? regs64->isf.rip : (user_addr_t)regs32->eip;
-               if (fuword8(pc - 1, &instr) == 0 && instr != FASTTRAP_INSTR) {
+               if (fuword8(pc - 1, &instr) == 0 && instr != FASTTRAP_INSTR && // neither single-byte INT3 (0xCC)
+                       !(instr == 3 && fuword8(pc - 2, &instr2) == 0 && instr2 == 0xCD)) { // nor two-byte INT 3 (0xCD03)
                        if (regs64) {
                                regs64->isf.rip--;
                        } else {