Added tests for bug detection on locals

runtime/szrt_asan.c

@@ -79,7 +79,10 @@ void __asan_check(char *ptr, int size) {
   for (; ptr < end; ++ptr) {
     char shadow = *(char *)MEM2SHADOW(ptr);
     printf("checking %p with shadow %d\n", ptr, shadow);
-    assert(shadow == 0 || (shadow > 0 && SHADOW_OFFSET(ptr) <= shadow));
+    if (shadow != 0 && (shadow < 0 || SHADOW_OFFSET(ptr) > shadow)) {
+      fprintf(stderr, "Illegal access of %d bytes at %p\n", size, ptr);
+      abort();
+    }
   }
 }
 

tests_lit/asan_tests/errors.ll

+; Verify that ASan properly catches and reports bugs
+
+; REQUIRES: no_minimal_build
+
+; check with a one off the end local access
+; RUN: llvm-as %s -o - | pnacl-freeze > %t.pexe && %S/../../pydir/szbuild.py \
+; RUN:     --fsanitize-address --sz="-allow-externally-defined-symbols" \
+; RUN:     %t.pexe -o %t && %t 2>&1 | FileCheck %s
+
+; check with a many off the end local access
+; RUN: llvm-as %s -o - | pnacl-freeze > %t.pexe && %S/../../pydir/szbuild.py \
+; RUN:     --fsanitize-address --sz="-allow-externally-defined-symbols" \
+; RUN:     %t.pexe -o %t && %t 1 2>&1 | FileCheck %s
+
+; check with a one before the front local access
+; RUN: llvm-as %s -o - | pnacl-freeze > %t.pexe && %S/../../pydir/szbuild.py \
+; RUN:     --fsanitize-address --sz="-allow-externally-defined-symbols" \
+; RUN:     %t.pexe -o %t && %t 1 2 2>&1 | FileCheck %s
+
+; check with a one off the end global access
+; RUIN: llvm-as %s -o - | pnacl-freeze > %t.pexe && %S/../../pydir/szbuild.py \
+; RUIN:     --fsanitize-address --sz="-allow-externally-defined-symbols" \
+; RUIN:     %t.pexe -o %t && %t 1 2 3 2>&1 | FileCheck %s
+
+; check with a many off the end global access
+; RUIN: llvm-as %s -o - | pnacl-freeze > %t.pexe && %S/../../pydir/szbuild.py \
+; RUIN:     --fsanitize-address --sz="-allow-externally-defined-symbols" \
+; RUIN:     %t.pexe -o %t && %t 1 2 3 4 2>&1 | FileCheck %s
+
+; check with a one before the front global access
+; RUIN: llvm-as %s -o - | pnacl-freeze > %t.pexe && %S/../../pydir/szbuild.py \
+; RUIN:     --fsanitize-address --sz="-allow-externally-defined-symbols" \
+; RUIN:     %t.pexe -o %t && %t 1 2 3 4 5 2>&1 | FileCheck %s
+
+
+declare external void @exit(i32)
+
+; A global array
+@array = internal constant [12 x i8] zeroinitializer
+
+define i32 @access(i32 %is_local_i, i32 %err) {
+  ; get the base pointer to either the local or global array
+  %local = alloca i8, i32 12, align 1
+  %global = bitcast [12 x i8]* @array to i8*
+  %is_local = icmp ne i32 %is_local_i, 0
+  %arr = select i1 %is_local, i8* %local, i8* %global
+
+  ; determine the offset to access
+  %err_offset = mul i32 %err, 4
+  %pos_offset = add i32 %err_offset, 12
+  %pos = icmp sge i32 %err_offset, 0
+  %offset = select i1 %pos, i32 %pos_offset, i32 %err
+
+  ; calculate the address to access
+  %arraddr = ptrtoint i8* %arr to i32
+  %badaddr = add i32 %arraddr, %offset
+  %badptr = inttoptr i32 %badaddr to i32*
+
+  ; perform the bad access
+  %result = load i32, i32* %badptr, align 1
+  ret i32 %result
+}
+
+; use argc to determine which test routine to run
+define void @_start(i32 %arg) {
+  %argcaddr = add i32 %arg, 8
+  %argcptr = inttoptr i32 %argcaddr to i32*
+  %argc = load i32, i32* %argcptr, align 1
+  switch i32 %argc, label %error [i32 1, label %one_local
+                                  i32 2, label %many_local
+                                  i32 3, label %neg_local]
+one_local:
+  ; Access one past the end
+  %__0 = call i32 @access(i32 1, i32 0)
+  br label %error
+many_local:
+  ; Access five past the end
+  %__1 = call i32 @access(i32 1, i32 4)
+  br label %error
+neg_local:
+  ; Access one before the beginning
+  %__2 = call i32 @access(i32 1, i32 -1)
+  br label %error
+error:
+  call void @exit(i32 1)
+  unreachable
+}
+
+; CHECK: Illegal access of 4 bytes at