svn commit: r279626 - head/sys/cddl/dev/fbt/arm

[Robert Watson]

Author: rwatson
Date: Thu Mar  5 07:40:41 2015
New Revision: 279626
URL: https://svnweb.freebsd.org/changeset/base/279626

Log:
  Don't all DTrace's FBT on ARM to instrument undefinedinstruction(), as
  this would lead to DTrace reentrance.
  
  Sponsored by:	DARPA, AFRL

Modified:
  head/sys/cddl/dev/fbt/arm/fbt_isa.c

Modified: head/sys/cddl/dev/fbt/arm/fbt_isa.c
==============================================================================
--- head/sys/cddl/dev/fbt/arm/fbt_isa.c	Thu Mar  5 07:30:48 2015	(r279625)
+++ head/sys/cddl/dev/fbt/arm/fbt_isa.c	Thu Mar  5 07:40:41 2015	(r279626)
@@ -105,6 +105,13 @@ fbt_provide_module_function(linker_file_
 	if (name[0] == '_' && name[1] == '_')
 		return (0);
 
+	/*
+	 * Architecture-specific exclusion list, largely to do with FBT trap
+	 * processing, to prevent reentrance.
+	 */
+	if (strcmp(name, "undefinedinstruction") == 0)
+		return (0);
+
 	instr = (uint32_t *)symval->value;
 	limit = (uint32_t *)(symval->value + symval->size);