[NFC][sanitizer] Remove calls to __asan_get_current_fake_stack

[kda]

Summary

Unnecessary with -fsanitize-address-use-after-return=never.

for issue: https://github.com/google/sanitizers/issues/1394

[vitalybuka]

I'd prefer we just update __asan_get_current_fake_stack()

[kda]

In D104154#2814441, @vitalybuka wrote:

I'd prefer we just update __asan_get_current_fake_stack()

Yeah, but all of these would prefer to assume that there is no fake stack.
With =never, there is no fake stack.

[vitalybuka]

compiler-rt/test/asan/TestCases/Posix/stack-overflow.cpp

71–72

And you can revert all "// RUN:" lines

compiler-rt/test/asan/TestCases/contiguous_container.cpp

72

why this does not work for fake stake?
do this tests fail with fake stack without __asan_get_current_fake_stack() check?

[vitalybuka]

compiler-rt/test/asan/TestCases/Posix/stack-overflow.cpp

78

87

112

[vitalybuka]

compiler-rt/test/asan/TestCases/Posix/stack-overflow.cpp

87

probably __builtin_frame_address is fine here as well

112

and here

[kda]

• remove UAR=never flag from contiguous_container.cpp.

compiler-rt/test/asan/TestCases/Posix/stack-overflow.cpp

71–72

I tried all these and it does not work.
__builtin_frame_address needs a parameter, I provided '0'.
recursive_func(-1): does not compile (cannot convert 'int' to 'char*').

Also, I think that passing -1 to recursive_func, is like passing a max INT, and consequently will always be greater than any value returned by __builtin_frame_address.
The above assert proves nothing.

compiler-rt/test/asan/TestCases/contiguous_container.cpp

72

I don't know why. I thought this looked useless and redundant, as the fake stack is off by default.
The test passes without the __asan_get_current_fake_stack check.

[vitalybuka]

use __builtin_frame_address

[vitalybuka]

I've updated the summary, usually shorter title of the git commit looks nicer.

compiler-rt/test/asan/TestCases/Posix/stack-overflow.cpp

71–72

I've updated the patch. Works this way.

compiler-rt/test/asan/TestCases/contiguous_container.cpp

72

I see
these are special cases when Asan bailout by poisoning entire stack (including callers) to make sure exception handler is executed on poisoned stack.
So for regular stack rezones it will remove red-zones around x[].
But we don't need to clear FakeStack, exception handler will just use new FakeFrame, so we can keep redzones in the current FakeStack around x[]

compiler-rt/test/asan/TestCases/Posix/stack-overflow.cpp

 #include <sys/resource.h>
 #include <sanitizer/asan_interface.h>
 
 const int BS = 1024;
 volatile char x;
 volatile int y = 1;
 volatile int z0, z1, z2, z3, z4, z5, z6, z7, z8, z9, z10, z11, z12, z13;
 
-void recursive_func(char *p) {
+void recursive_func(uintptr_t parent_frame_address) {
 #if defined(SMALL_FRAME)
   char *buf = 0;
 #elif defined(SAVE_ALL_THE_REGISTERS)
   char *buf = 0;
   int t0, t1, t2, t3, t4, t5, t6, t7, t8, t9, t10, t11, t12, t13;
   t0 = z0;
   t1 = z1;
   t2 = z2;
#elif defined(SAVE_ALL_THE_REGISTERS)
   z8 = t8;
   z9 = t9;
   z10 = t10;
   z11 = t11;
   z12 = t12;
   z13 = t13;
 #else
   char buf[BS];
   // Check that the stack grows in the righ direction, unless we use fake stack.
-  if (p && !__asan_get_current_fake_stack())
-    assert(p - buf >= BS);
+  assert(parent_frame_address > (uintptr_t)__builtin_frame_address(0));
   buf[rand() % BS] = 1;
   buf[rand() % BS] = 2;
   x = buf[rand() % BS];
 #endif
   if (y)
-    recursive_func(buf);
+    recursive_func((uintptr_t)__builtin_frame_address(0));
   x = 1; // prevent tail call optimization
   // CHECK: {{stack-overflow on address 0x.* \(pc 0x.* bp 0x.* sp 0x.* T.*\)}}
   // If stack overflow happens during function prologue, stack trace may be
   // corrupted. Unwind tables are not always 100% exact there.
   // For this reason, we don't do any further checks.
 }
 
 void *ThreadFn(void* unused) {
-  recursive_func(0);
+  recursive_func((uintptr_t)__builtin_frame_address(0));
   return 0;
 }
 
 void LimitStackAndReexec(int argc, char **argv) {
   struct rlimit rlim;
   int res = getrlimit(RLIMIT_STACK, &rlim);
   assert(res == 0);
   if (rlim.rlim_cur == RLIM_INFINITY) {
     rlim.rlim_cur = 256 * 1024;
     res = setrlimit(RLIMIT_STACK, &rlim);
     assert(res == 0);
 
     execv(argv[0], argv);
     assert(0 && "unreachable");
   }
 }
 
 int main(int argc, char **argv) {
   LimitStackAndReexec(argc, argv);
 #ifdef THREAD
   pthread_t t;
   pthread_create(&t, 0, ThreadFn, 0);
   pthread_join(t, 0);
 #else
-  recursive_func(0);
+  recursive_func((uintptr_t)__builtin_frame_address(0));
 #endif
   return 0;
 }

compiler-rt/test/asan/TestCases/contiguous_container.cpp

 
 void TestThrow() {
   char x[32];
   __sanitizer_annotate_contiguous_container(x, x + 32, x + 32, x + 14);
   assert(!__asan_address_is_poisoned(x + 13));
   assert(__asan_address_is_poisoned(x + 14));
   ThrowAndCatch();
   assert(!__asan_address_is_poisoned(x + 13));
-  // FIXME: invert the assertion below once we fix
-  // https://code.google.com/p/address-sanitizer/issues/detail?id=258
-  // This assertion works only w/o UAR.
-  if (!__asan_get_current_fake_stack())
-    assert(!__asan_address_is_poisoned(x + 14));
   __sanitizer_annotate_contiguous_container(x, x + 32, x + 14, x + 32);
   assert(!__asan_address_is_poisoned(x + 13));
   assert(!__asan_address_is_poisoned(x + 14));
 }
 
 int main(int argc, char **argv) {
   int n = argc == 1 ? 128 : atoi(argv[1]);
   for (int i = 0; i <= n; i++)
     TestContainer(i);
   TestThrow();
 }

compiler-rt/test/asan/TestCases/longjmp.cpp

-// RUN: %clangxx_asan -O %s -o %t && %run %t
+// RUN: %clangxx_asan -fsanitize-address-use-after-return=never -O %s -o %t && %run %t
 
 #include <assert.h>
 #include <setjmp.h>
 #include <stdio.h>
 #include <sanitizer/asan_interface.h>
 
 static jmp_buf buf;
 
 int main() {
   char x[32];
   fprintf(stderr, "\nTestLongJmp\n");
   fprintf(stderr, "Before: %p poisoned: %d\n", &x,
           __asan_address_is_poisoned(x + 32));
   assert(__asan_address_is_poisoned(x + 32));
   if (0 == setjmp(buf))
     longjmp(buf, 1);
   fprintf(stderr, "After:  %p poisoned: %d\n",  &x,
           __asan_address_is_poisoned(x + 32));
-  // FIXME: Invert this assertion once we fix
-  // https://code.google.com/p/address-sanitizer/issues/detail?id=258
-  // This assertion works only w/o UAR.
-  if (!__asan_get_current_fake_stack())
-    assert(!__asan_address_is_poisoned(x + 32));
 }

compiler-rt/test/asan/TestCases/throw_catch.cpp

-// RUN: %clangxx_asan -O %s -o %t && %run %t
+// RUN: %clangxx_asan -fsanitize-address-use-after-return=never -O %s -o %t && %run %t
 
 #include <assert.h>
 #include <stdio.h>
 #include <sanitizer/asan_interface.h>
 
 __attribute__((noinline))
 void Throw() {
   int local;

 void TestThrow() {
   char x[32];
   fprintf(stderr, "Before: %p poisoned: %d\n", &x,
           __asan_address_is_poisoned(x + 32));
   assert(__asan_address_is_poisoned(x + 32));
   ThrowAndCatch();
   fprintf(stderr, "After:  %p poisoned: %d\n",  &x,
           __asan_address_is_poisoned(x + 32));
-  // FIXME: Invert this assertion once we fix
-  // https://code.google.com/p/address-sanitizer/issues/detail?id=258
-  // This assertion works only w/o UAR.
-  if (!__asan_get_current_fake_stack())
-    assert(!__asan_address_is_poisoned(x + 32));
 }
 
 __attribute__((noinline))
 void TestThrowInline() {
   char x[32];
   fprintf(stderr, "Before: %p poisoned: %d\n", &x,
           __asan_address_is_poisoned(x + 32));
   assert(__asan_address_is_poisoned(x + 32));
   try {
     Throw();
   } catch(...) {
     fprintf(stderr, "Catch\n");
   }
   fprintf(stderr, "After:  %p poisoned: %d\n",  &x,
           __asan_address_is_poisoned(x + 32));
-  // FIXME: Invert this assertion once we fix
-  // https://code.google.com/p/address-sanitizer/issues/detail?id=258
-  // This assertion works only w/o UAR.
-  if (!__asan_get_current_fake_stack())
-    assert(!__asan_address_is_poisoned(x + 32));
 }
 
 int main(int argc, char **argv) {
   TestThrowInline();
   TestThrow();
 }