cfgexpand.c (expand_stack_vars): Optionally disable asan stack protection.

2014-01-09  Max Ostapenko  <m.ostapenko@partner.samsung.com>

	* cfgexpand.c (expand_stack_vars): Optionally disable 
	asan stack protection.
	(expand_used_vars): Likewise.
	(partition_stack_vars): Likewise.
	* asan.c (asan_emit_stack_protection): Optionally disable 
	after return stack usage.
	(instrument_derefs): Optionally disable memory 
	access instrumentation.
	(instrument_builtin_call): Likewise.
	(instrument_strlen_call): Likewise.
	(asan_protect_global): Optionally disable 
	global variables protection.
	* doc/invoke.texi: Added doc for new options.
	* params.def: Added new options.
	* params.h: Likewise.

2014-01-09  Max Ostapenko  <m.ostapenko@partner.samsung.com>

	* c-c++-common/asan/no-asan-globals.c: New test.
	* c-c++-common/asan/no-instrument-reads.c: Likewise.
	* c-c++-common/asan/no-instrument-writes.c: Likewise.
	* c-c++-common/asan/use-after-return-1.c: Likewise.
	* c-c++-common/asan/no-use-after-return.c: Likewise.

From-SVN: r206458

gcc/ChangeLog

+2014-01-09  Max Ostapenko  <m.ostapenko@partner.samsung.com>
+
+	* cfgexpand.c (expand_stack_vars): Optionally disable 
+	asan stack protection.
+	(expand_used_vars): Likewise.
+	(partition_stack_vars): Likewise.
+	* asan.c (asan_emit_stack_protection): Optionally disable 
+	after return stack usage.
+	(instrument_derefs): Optionally disable memory 
+	access instrumentation.
+	(instrument_builtin_call): Likewise.
+	(instrument_strlen_call): Likewise.
+	(asan_protect_global): Optionally disable 
+	global variables protection.
+	* doc/invoke.texi: Added doc for new options.
+	* params.def: Added new options.
+	* params.h: Likewise.
+
 2014-01-09  Jakub Jelinek  <jakub@redhat.com>
 
 	PR rtl-optimization/59724

gcc/asan.c

@@ -53,6 +53,7 @@ along with GCC; see the file COPYING3.  If not see
 #include "gimple-builder.h"
 #include "ubsan.h"
 #include "predict.h"
+#include "params.h"
 
 /* AddressSanitizer finds out-of-bounds and use-after-free bugs
    with <2x slowdown on average.
@@ -1003,7 +1004,8 @@ asan_emit_stack_protection (rtx base, rtx pbase, unsigned int alignb,
   str_cst = asan_pp_string (&asan_pp);
 
   /* Emit the prologue sequence.  */
-  if (asan_frame_size > 32 && asan_frame_size <= 65536 && pbase)
+  if (asan_frame_size > 32 && asan_frame_size <= 65536 && pbase
+      && ASAN_USE_AFTER_RETURN)
     {
       use_after_return_class = floor_log2 (asan_frame_size - 1) - 5;
       /* __asan_stack_malloc_N guarantees alignment
@@ -1239,6 +1241,9 @@ asan_needs_local_alias (tree decl)
 bool
 asan_protect_global (tree decl)
 {
+  if (!ASAN_GLOBALS)
+    return false;
+
   rtx rtl, symbol;
 
   if (TREE_CODE (decl) == STRING_CST)
@@ -1568,6 +1573,11 @@ static void
 instrument_derefs (gimple_stmt_iterator *iter, tree t,
 		   location_t location, bool is_store)
 {
+  if (is_store && !ASAN_INSTRUMENT_WRITES)
+    return;
+  if (!is_store && !ASAN_INSTRUMENT_READS)
+    return;
+
   tree type, base;
   HOST_WIDE_INT size_in_bytes;
 
@@ -1897,6 +1907,9 @@ instrument_strlen_call (gimple_stmt_iterator *iter)
 static bool
 instrument_builtin_call (gimple_stmt_iterator *iter)
 {
+  if (!ASAN_MEMINTRIN)
+    return false;
+
   bool iter_advanced_p = false;
   gimple call = gsi_stmt (*iter);
 

gcc/cfgexpand.c

@@ -798,7 +798,7 @@ partition_stack_vars (void)
 	     sizes, as the shorter vars wouldn't be adequately protected.
 	     Don't do that for "large" (unsupported) alignment objects,
 	     those aren't protected anyway.  */
-	  if ((flag_sanitize & SANITIZE_ADDRESS) && isize != jsize
+	  if ((flag_sanitize & SANITIZE_ADDRESS) && ASAN_STACK && isize != jsize
 	      && ialign * BITS_PER_UNIT <= MAX_SUPPORTED_STACK_ALIGNMENT)
 	    break;
 
@@ -981,7 +981,7 @@ expand_stack_vars (bool (*pred) (size_t), struct stack_vars_data *data)
       if (alignb * BITS_PER_UNIT <= MAX_SUPPORTED_STACK_ALIGNMENT)
 	{
 	  base = virtual_stack_vars_rtx;
-	  if ((flag_sanitize & SANITIZE_ADDRESS) && pred)
+	  if ((flag_sanitize & SANITIZE_ADDRESS) && ASAN_STACK && pred)
 	    {
 	      HOST_WIDE_INT prev_offset = frame_offset;
 	      tree repr_decl = NULL_TREE;
@@ -1160,7 +1160,7 @@ defer_stack_allocation (tree var, bool toplevel)
   /* If stack protection is enabled, *all* stack variables must be deferred,
      so that we can re-order the strings to the top of the frame.
      Similarly for Address Sanitizer.  */
-  if (flag_stack_protect || (flag_sanitize & SANITIZE_ADDRESS))
+  if (flag_stack_protect || ((flag_sanitize & SANITIZE_ADDRESS) && ASAN_STACK))
     return true;
 
   /* We handle "large" alignment via dynamic allocation.  We want to handle
@@ -1820,7 +1820,7 @@ expand_used_vars (void)
 	    expand_stack_vars (stack_protect_decl_phase_2, &data);
 	}
 
-      if (flag_sanitize & SANITIZE_ADDRESS)
+      if ((flag_sanitize & SANITIZE_ADDRESS) && ASAN_STACK)
 	/* Phase 3, any partitions that need asan protection
 	   in addition to phase 1 and 2.  */
 	expand_stack_vars (asan_decl_phase_3, &data);

gcc/doc/invoke.texi

@@ -10065,6 +10065,41 @@ The default choice depends on the target.
 Set the maximum number of existing candidates that will be considered when
 seeking a basis for a new straight-line strength reduction candidate.
 
+@item asan-globals
+Enable buffer overflow detection for global objects.  This kind
+of protection is enabled by default if you are using
+@option{-fsanitize=address} option.
+To disable global objects protection use @option{--param asan-globals=0}.
+
+@item asan-stack
+Enable buffer overflow detection for stack objects.  This kind of
+protection is enabled by default when using@option{-fsanitize=address}.
+To disable stack protection use @option{--param asan-stack=0} option.
+
+@item asan-instrument-reads
+Enable buffer overflow detection for memory reads.  This kind of
+protection is enabled by default when using @option{-fsanitize=address}.
+To disable memory reads protection use
+@option{--param asan-instrument-reads=0}.
+
+@item asan-instrument-writes
+Enable buffer overflow detection for memory writes.  This kind of
+protection is enabled by default when using @option{-fsanitize=address}.
+To disable memory writes protection use
+@option{--param asan-instrument-writes=0} option.
+
+@item asan-memintrin
+Enable detection for built-in functions.  This kind of protection
+is enabled by default when using @option{-fsanitize=address}.
+To disable built-in functions protection use
+@option{--param asan-memintrin=0}.
+
+@item asan-use-after-return
+Enable detection of use-after-return.  This kind of protection
+is enabled by default when using @option{-fsanitize=address} option.
+To disable use-after-return detection use 
+@option{--param asan-use-after-return=0}.
+
 @end table
 @end table
 

gcc/params.def

@@ -1049,7 +1049,37 @@ DEFPARAM (PARAM_MAX_SLSR_CANDIDATE_SCAN,
 	  "strength reduction",
 	  50, 1, 999999)
 
+DEFPARAM (PARAM_ASAN_STACK,
+         "asan-stack",
+         "Enable asan stack protection",
+         1, 0, 1)
+
+DEFPARAM (PARAM_ASAN_GLOBALS,
+         "asan-globals",
+         "Enable asan globals protection",
+         1, 0, 1)
+
+DEFPARAM (PARAM_ASAN_INSTRUMENT_WRITES,
+         "asan-instrument-writes",
+         "Enable asan store operations protection",
+         1, 0, 1)
+
+DEFPARAM (PARAM_ASAN_INSTRUMENT_READS,
+         "asan-instrument-reads",
+         "Enable asan load operations protection",
+         1, 0, 1)
+
+DEFPARAM (PARAM_ASAN_MEMINTRIN,
+         "asan-memintrin",
+         "Enable asan builtin functions protection",
+         1, 0, 1)
+
+DEFPARAM (PARAM_ASAN_USE_AFTER_RETURN,
+         "asan-use-after-return",
+         "Enable asan builtin functions protection",
+         1, 0, 1)
 /*
+
 Local variables:
 mode:c
 End:

gcc/params.h

@@ -218,5 +218,17 @@ extern void init_param_values (int *params);
   PARAM_VALUE (PARAM_ALLOW_PACKED_LOAD_DATA_RACES)
 #define ALLOW_PACKED_STORE_DATA_RACES \
   PARAM_VALUE (PARAM_ALLOW_PACKED_STORE_DATA_RACES)
+#define ASAN_STACK \
+  PARAM_VALUE (PARAM_ASAN_STACK)
+#define ASAN_GLOBALS \
+  PARAM_VALUE (PARAM_ASAN_GLOBALS)
+#define ASAN_INSTRUMENT_READS \
+  PARAM_VALUE (PARAM_ASAN_INSTRUMENT_READS)
+#define ASAN_INSTRUMENT_WRITES \
+  PARAM_VALUE (PARAM_ASAN_INSTRUMENT_WRITES)
+#define ASAN_MEMINTRIN \
+  PARAM_VALUE (PARAM_ASAN_MEMINTRIN)
+#define ASAN_USE_AFTER_RETURN \
+  PARAM_VALUE (PARAM_ASAN_USE_AFTER_RETURN)
 
 #endif /* ! GCC_PARAMS_H */

gcc/testsuite/ChangeLog

+2014-01-09  Max Ostapenko  <m.ostapenko@partner.samsung.com>
+
+	* c-c++-common/asan/no-asan-globals.c: New test.
+	* c-c++-common/asan/no-instrument-reads.c: Likewise.
+	* c-c++-common/asan/no-instrument-writes.c: Likewise.
+	* c-c++-common/asan/use-after-return-1.c: Likewise.
+	* c-c++-common/asan/no-use-after-return.c: Likewise.
+
 2014-01-08  Eric Botcazou  <ebotcazou@adacore.com>
 
 	* gnat.dg/weak2.ad[sb]: New test.

gcc/testsuite/c-c++-common/asan/no-asan-globals.c

+/* { dg-do assemble } */
+/* { dg-options "-save-temps --param asan-globals=0" } */
+
+volatile int ten = 10;
+
+int main() {
+  volatile static char XXX[10];
+  XXX[ten];
+  return 0;
+}
+
+/* { dg-final { scan-assembler-not "__asan_register_globals" } } */
+/* { dg-final { cleanup-saved-temps } } */

gcc/testsuite/c-c++-common/asan/no-instrument-reads.c

+/* { dg-do assemble } */
+/* { dg-options "--param asan-instrument-reads=0 -save-temps" } */
+
+volatile int ten = 10;
+
+int main() {
+  volatile char x[10];
+  x[ten];
+  return 0;
+}
+
+/* { dg-final { scan-assembler-not "__asan_load" } } */
+/* { dg-final { cleanup-saved-temps } } */

gcc/testsuite/c-c++-common/asan/no-instrument-writes.c

+/* { dg-do assemble } */
+/* { dg-options "--param asan-instrument-writes=0 -save-temps" } */
+
+volatile int ten = 10;
+
+int main() {
+  volatile char x[10];
+  x[ten] = 1;
+  return 0;
+}
+
+/* { dg-final { scan-assembler-not "__asan_store" } } */
+/* { dg-final { cleanup-saved-temps } } */

gcc/testsuite/c-c++-common/asan/no-use-after-return.c

+/* { dg-do assemble } */
+/* { dg-options "--param asan-use-after-return=0 -save-temps" } */
+
+extern void f(char *);
+
+int main() {
+  char buf[64];
+  f(buf);
+  return 0;
+}
+
+/* { dg-final { scan-assembler-not "__asan_option_detect_stack_use_after_return" } } */
+/* { dg-final { cleanup-saved-temps } } */

gcc/testsuite/c-c++-common/asan/use-after-return-1.c

+/* { dg-do run } */
+/* { dg-set-target-env-var ASAN_OPTIONS "detect_stack_use_after_return=1" } */
+/* { dg-shouldfail "asan" } */
+
+#include <stdio.h>
+#include <pthread.h>
+
+#ifndef kSize
+# define kSize 1
+#endif
+
+#ifndef UseThread
+# define UseThread 0
+#endif
+
+__attribute__((noinline))
+char *Ident(char *x) {
+  fprintf(stderr, "1: %p\n", x);
+  return x;
+}
+
+__attribute__((noinline))
+char *Func1() {
+  char local[kSize];
+  return Ident(local);
+}
+
+__attribute__((noinline))
+void Func2(char *x) {
+  fprintf(stderr, "2: %p\n", x);
+  *x = 1;
+}
+
+void *Thread(void *unused)  {
+  Func2(Func1());
+  return NULL;
+}
+
+int main(int argc, char **argv) {
+#if UseThread
+  pthread_t t;
+  pthread_create(&t, 0, Thread, 0);
+  pthread_join(t, 0);
+#else
+  Func2(Func1());
+#endif
+  return 0;
+}
+
+/* { dg-output "WRITE of size 1 at .* thread T0.*" } */
+/* { dg-output "    #0.*Func2.*use-after-return-1.c:31.*" } */
+/* { dg-output "is located in stack of thread T0 at offset.*" } */
+/* { dg-output "\'local\' <== Memory access at offset 32 is inside this variable" } */