2007-02-06 Josh Stone <joshua.i.stone@intel.com>

runtime/
	* loc2c-runtime.h (kread): Let it work with const types.

testsuite/
	* systemtap.base/deref.stp: Test kread with const sources.

4 files changed, 50 insertions, 10 deletions

diff --git a/runtime/ChangeLog b/runtime/ChangeLog
index 95cf3483..d56a64a7 100644
--- a/runtime/ChangeLog
+++ b/runtime/ChangeLog
@@ -1,3 +1,7 @@
+2007-02-06  Josh Stone  <joshua.i.stone@intel.com>
+
+	* loc2c-runtime.h (kread): Let it work with const types.
+
 2007-01-31  Martin Hunt  <hunt@redhat.com>
 	
 	* string.c (_stp_string_init): Deleted.
diff --git a/runtime/loc2c-runtime.h b/runtime/loc2c-runtime.h
index 7ed9d415..8ccc9826 100644
--- a/runtime/loc2c-runtime.h
+++ b/runtime/loc2c-runtime.h
@@ -467,16 +467,12 @@
 
 /* x86 can't do 8-byte put/get_user_asm, so we have to split it */
 
-#define kread(ptr)						\
-  ({								\
-    union { typeof(*(ptr)) v; u32 l[2]; } _kr;			\
-    if (sizeof(*(ptr)) == 8) {					\
-      _kr.l[0] = (u32) deref(4, &((u32 *)(ptr))[0]);		\
-      _kr.l[1] = (u32) deref(4, &((u32 *)(ptr))[1]);		\
-    } else							\
-      _kr.v = (typeof(*(ptr))) deref(sizeof(*(ptr)), (ptr));	\
-    _kr.v;							\
-  })
+#define kread(ptr)					\
+  ((sizeof(*(ptr)) == 8) ?				\
+       *(typeof(ptr))&(u32[2]) {			\
+	 (u32) deref(4, &((u32 *)(ptr))[0]),		\
+	 (u32) deref(4, &((u32 *)(ptr))[1]) }		\
+     : (typeof(*(ptr))) deref(sizeof(*(ptr)), (ptr)))
 
 #define kwrite(ptr, value)						     \
   ({									     \
diff --git a/testsuite/ChangeLog b/testsuite/ChangeLog
index fcae70c3..18226d54 100644
--- a/testsuite/ChangeLog
+++ b/testsuite/ChangeLog
@@ -1,3 +1,7 @@
+2007-02-06  Josh Stone  <joshua.i.stone@intel.com>
+
+	* systemtap.base/deref.stp: Test kread with const sources.
+
 2007-02-06  Frank Ch. Eigler  <fche@elastic.org>
 
 	* buildok/conversions.stp: Build-test all conversions.stp functions.
diff --git a/testsuite/systemtap.base/deref.stp b/testsuite/systemtap.base/deref.stp
index d2399589..b003d657 100644
--- a/testsuite/systemtap.base/deref.stp
+++ b/testsuite/systemtap.base/deref.stp
@@ -14,6 +14,12 @@ probe end(1) {
   log_test("kread u64", kread_u64())
   log_test("kread ptr", kread_ptr())
 
+  log_test("kread const u8", kread_const_u8())
+  log_test("kread const u16", kread_const_u16())
+  log_test("kread const u32", kread_const_u32())
+  log_test("kread const u64", kread_const_u64())
+  log_test("kread const ptr", kread_const_ptr())
+
   log_test("kwrite u8", kwrite_u8())
   log_test("kwrite u16", kwrite_u16())
   log_test("kwrite u32", kwrite_u32())
@@ -58,6 +64,36 @@ function kread_ptr:long() %{
   CATCH_DEREF_FAULT();
 %}
 
+function kread_const_u8:long() %{
+  const uint8_t local = 0x42;
+  THIS->__retvalue = (local == kread(&local));
+  CATCH_DEREF_FAULT();
+%}
+
+function kread_const_u16:long() %{
+  const uint16_t local = 0xBEEF;
+  THIS->__retvalue = (local == kread(&local));
+  CATCH_DEREF_FAULT();
+%}
+
+function kread_const_u32:long() %{
+  const uint32_t local = 0xDEADBEEF;
+  THIS->__retvalue = (local == kread(&local));
+  CATCH_DEREF_FAULT();
+%}
+
+function kread_const_u64:long() %{
+  const uint64_t local = 0xDEADBEEFBAADF00DLL;
+  THIS->__retvalue = (local == kread(&local));
+  CATCH_DEREF_FAULT();
+%}
+
+function kread_const_ptr:long() %{
+  const struct task_struct *local = current;
+  THIS->__retvalue = (local == kread(&local));
+  CATCH_DEREF_FAULT();
+%}
+
 // NB: kwrite uses system macros with inline asm, with this comment:
 //
 //   Tell gcc we read from memory instead of writing: this is because we do not