clang/test/CodeGen/sanitize-memory-disable.c

   1 // RUN: %clang -target x86_64-linux-gnu -S -emit-llvm -o - %s | FileCheck -check-prefixes CHECK,WITHOUT %s
   2 // RUN: %clang -target x86_64-linux-gnu -S -emit-llvm -o - %s -fsanitize=memory | FileCheck -check-prefixes CHECK,MSAN %s
   3 // RUN: %clang -target x86_64-linux-gnu -S -emit-llvm -o - %s -fsanitize=kernel-memory | FileCheck -check-prefixes CHECK,KMSAN %s
   4 // RUN: %clang -target x86_64-linux-gnu -S -emit-llvm -o - %s -fsanitize=memory -fno-sanitize-memory-param-retval | FileCheck -check-prefixes CHECK,MSAN,RETTLS %s
   5
   6 // Instrumented function.
   7 // MSan uses memset(addr, -1, size) to poison allocas and stores shadow of the return value in
   8 // __msan_retval_tls. KMSAN uses __msan_poison_alloca() to poison allocas and calls
   9 // __msan_get_context_state() at function prologue to access the task context struct (including the
  10 // shadow of the return value).
  11 //
  12 // CHECK-LABEL: i32 @instrumented1
  13 // KMSAN: __msan_get_context_state
  14 // WITHOUT-NOT: __msan_poison_alloca
  15 // WITHOUT-NOT: @llvm.memset
  16 // MSAN: @llvm.memset{{.*}}({{.*}}, i8 -1
  17 // KMSAN: __msan_poison_alloca
  18 // WITHOUT-NOT: __msan_retval_tls
  19 // RETTLS: __msan_retval_tls
  20 // CHECK: ret i32
  21 int instrumented1(int *a) {
  22   volatile char buf[8];
  23   return *a;
  24 }
  25
  26 // Function with no_sanitize("memory")/no_sanitize("kernel-memory"): no shadow propagation, but
  27 // unpoisons memory to prevent false positives.
  28 // MSan uses memset(addr, 0, size) to unpoison locals, KMSAN uses __msan_unpoison_alloca(). Both
  29 // tools still access the retval shadow to write 0 to it.
  30 //
  31 // CHECK-LABEL: i32 @no_false_positives1
  32 // KMSAN: __msan_get_context_state
  33 // WITHOUT-NOT: __msan_unpoison_alloca
  34 // WITHOUT-NOT: @llvm.memset
  35 // MSAN: @llvm.memset{{.*}}({{.*}}, i8 0
  36 // KMSAN: __msan_unpoison_alloca
  37 // WITHOUT-NOT: __msan_retval_tls
  38 // RETTLS: __msan_retval_tls
  39 // CHECK: ret i32
  40 __attribute__((no_sanitize("memory"))) __attribute__((no_sanitize("kernel-memory"))) int no_false_positives1(int *a) {
  41   volatile char buf[8];
  42   return *a;
  43 }
  44
  45 // Function with disable_sanitizer_instrumentation: no instrumentation at all.
  46 //
  47 // CHECK-LABEL: i32 @no_instrumentation1
  48 // KMSAN-NOT: __msan_get_context_state
  49 // WITHOUT-NOT: __msan_poison_alloca
  50 // WITHOUT-NOT: @llvm.memset
  51 // MSAN-NOT: @llvm.memset{{.*}}({{.*}}, i8 0
  52 // KMSAN-NOT: __msan_unpoison_alloca
  53 // WITHOUT-NOT: __msan_retval_tls
  54 // MSAN-NOT: __msan_retval_tls
  55 // CHECK: ret i32
  56 __attribute__((disable_sanitizer_instrumentation)) int no_instrumentation1(int *a) {
  57   volatile char buf[8];
  58   return *a;
  59 }