llvm-project/compiler-rt/lib/interception/tests/interception_linux_foreign_test.cpp
Marco Elver 37445e96d8 [compiler-rt] Allow 3 simultaneous interceptors on Linux
Rework Linux (and *BSD) interceptors to allow for up to 3 (2 for *BSD)
simultaneous interceptors. See code comments for details.

The main motivation is to support new sampling sanitizers (in the spirit
of GWP-ASan), that have to intercept few functions. Unfortunately, the
reality is that there are user interceptors that exist in the wild.

To support foreign user interceptors, foreign dynamic analysis
interceptors, and compiler-rt interceptors all at the same time,
including any combination of them, this change enables up to 3
interceptors on Linux (2 on *BSD).

v2:
* Revert to to the simpler "weak wrapper -(alias)-> __interceptor"
  scheme on architectures that cannot implement a trampoline efficiently
  due to complexities of resolving a preemptible symbol (PowerPC64
  ELFv2 global entry, and i386 PIC).
* Avoid duplicate intercepted functions in gen_dynamic_list.py, due to
  matching __interceptor_X and ___interceptor_X.
* Fix s390 __tls_get_offset.

Reviewed By: dvyukov, MaskRay, vitalybuka

Differential Revision: https://reviews.llvm.org/D151085
2023-06-09 11:30:41 +02:00

97 lines
2.8 KiB
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//===-- interception_linux_foreign_test.cpp -------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This file is a part of ThreadSanitizer/AddressSanitizer runtime.
//
// Tests that foreign interceptors work.
//
//===----------------------------------------------------------------------===//
// Do not declare functions in ctype.h.
#define __NO_CTYPE
#include "gtest/gtest.h"
#include "sanitizer_common/sanitizer_asm.h"
#include "sanitizer_common/sanitizer_internal_defs.h"
#if SANITIZER_LINUX
extern "C" int isalnum(int d);
extern "C" int __interceptor_isalpha(int d);
extern "C" int ___interceptor_isalnum(int d); // the sanitizer interceptor
extern "C" int ___interceptor_islower(int d); // the sanitizer interceptor
namespace __interception {
extern int isalpha_called;
extern int isalnum_called;
extern int islower_called;
} // namespace __interception
using namespace __interception;
// Direct foreign interceptor. This is the "normal" protocol that other
// interceptors should follow.
extern "C" int isalpha(int d) {
// Use non-commutative arithmetic to verify order of calls.
isalpha_called = isalpha_called * 10 + 1;
return __interceptor_isalpha(d);
}
#if ASM_INTERCEPTOR_TRAMPOLINE_SUPPORT
// Indirect foreign interceptor. This pattern should only be used to co-exist
// with direct foreign interceptors and sanitizer interceptors.
extern "C" int __interceptor_isalnum(int d) {
isalnum_called = isalnum_called * 10 + 1;
return ___interceptor_isalnum(d);
}
extern "C" int __interceptor_islower(int d) {
islower_called = islower_called * 10 + 2;
return ___interceptor_islower(d);
}
extern "C" int islower(int d) {
islower_called = islower_called * 10 + 1;
return __interceptor_islower(d);
}
#endif // ASM_INTERCEPTOR_TRAMPOLINE_SUPPORT
namespace __interception {
TEST(ForeignInterception, ForeignOverrideDirect) {
isalpha_called = 0;
EXPECT_NE(0, isalpha('a'));
EXPECT_EQ(13, isalpha_called);
isalpha_called = 0;
EXPECT_EQ(0, isalpha('_'));
EXPECT_EQ(13, isalpha_called);
}
#if ASM_INTERCEPTOR_TRAMPOLINE_SUPPORT
TEST(ForeignInterception, ForeignOverrideIndirect) {
isalnum_called = 0;
EXPECT_NE(0, isalnum('a'));
EXPECT_EQ(13, isalnum_called);
isalnum_called = 0;
EXPECT_EQ(0, isalnum('_'));
EXPECT_EQ(13, isalnum_called);
}
TEST(ForeignInterception, ForeignOverrideThree) {
islower_called = 0;
EXPECT_NE(0, islower('a'));
EXPECT_EQ(123, islower_called);
islower_called = 0;
EXPECT_EQ(0, islower('_'));
EXPECT_EQ(123, islower_called);
}
#endif // ASM_INTERCEPTOR_TRAMPOLINE_SUPPORT
} // namespace __interception
#endif // SANITIZER_LINUX