i#2118: use long jump for 16-byte address checks (#2120)
16-byte memrefs end up with long instrumentation sequences from
add_check_partial_undefined()'s list of shadow pattern possibilities.
We use a longer jump to avoid reachability issues.
Adds a test to asmtest.
Fixes #2118
diff --git a/drmemory/fastpath_x86.c b/drmemory/fastpath_x86.c
index 6a9404b..c5c93c9 100644
--- a/drmemory/fastpath_x86.c
+++ b/drmemory/fastpath_x86.c
@@ -1,5 +1,5 @@
/* **********************************************************
- * Copyright (c) 2010-2017 Google, Inc. All rights reserved.
+ * Copyright (c) 2010-2018 Google, Inc. All rights reserved.
* Copyright (c) 2008-2010 VMware, Inc. All rights reserved.
* **********************************************************/
@@ -1836,7 +1836,11 @@
add_jcc_slowpath(drcontext, bb, inst,
/* short doesn't quite reach for mem2mem's 1st check
* FIXME: use short for 2nd though! */
+ /* XXX DRi#56: have a pass to auto-convert short jumps
+ * to long that don't reach; some new drx_ utility maybe. */
(mi->mem2mem || mi->load2x ||
+ /* i#2118: 16-byte add_check_partial_undefined() */
+ mi->memsz > 8 ||
/* new zero-src check => require long */
instr_needs_all_srcs_and_vals(inst) ||
(mi->memsz < 4 && !opnd_is_null(mi->src[1].app))) ?
@@ -1855,6 +1859,8 @@
mark_eflags_used(drcontext, bb, mi->bb);
add_jcc_slowpath(drcontext, bb, inst,
(mi->mem2mem || mi->load2x ||
+ /* i#2118: 16-byte add_check_partial_undefined() */
+ mi->memsz > 8 ||
/* new zero-src check => require long */
instr_needs_all_srcs_and_vals(inst) ||
(mi->memsz < 4 && !opnd_is_null(mi->src[1].app))) ?
diff --git a/tests/asmtest_x86.c b/tests/asmtest_x86.c
index 30caa91..53bb82b 100644
--- a/tests/asmtest_x86.c
+++ b/tests/asmtest_x86.c
@@ -1,5 +1,5 @@
/* **********************************************************
- * Copyright (c) 2014-2017 Google, Inc. All rights reserved.
+ * Copyright (c) 2014-2018 Google, Inc. All rights reserved.
* **********************************************************/
/* Dr. Memory: the memory debugger
@@ -32,6 +32,7 @@
void asm_test(char *undef, char *def);
void asm_test_avx(char *undef, char *def);
void asm_test_i1680(char *buf);
+void asm_test_reach(void);
static void
asm_test_C(void)
@@ -41,6 +42,7 @@
asm_test(undef, def);
asm_test_avx(undef, def);
asm_test_i1680(def);
+ asm_test_reach();
}
int
@@ -454,5 +456,17 @@
#undef FUNCNAME
+#define FUNCNAME asm_test_reach
+/* Tests i#2118 reachability. */
+/* void asm_test_reach(); */
+ DECLARE_FUNC_SEH(FUNCNAME)
+GLOBAL_LABEL(FUNCNAME:)
+ mov eax, 0
+ movdqu XMMWORD [8 + REG_XSP + REG_XAX], xmm0
+ ret
+ END_FUNC(FUNCNAME)
+#undef FUNCNAME
+
+
END_FILE
#endif
