//===-- sanitizer_tls_get_addr.h --------------------------------*- C++ -*-===// // // 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 // //===----------------------------------------------------------------------===// // // Handle the __tls_get_addr call. // // All this magic is specific to glibc and is required to workaround // the lack of interface that would tell us about the Dynamic TLS (DTLS). // https://sourceware.org/bugzilla/show_bug.cgi?id=16291 // // The matters get worse because the glibc implementation changed between // 2.18 and 2.19: // https://groups.google.com/forum/#!topic/address-sanitizer/BfwYD8HMxTM // // Before 2.19, every DTLS chunk is allocated with __libc_memalign, // which we intercept and thus know where is the DTLS. // Since 2.19, DTLS chunks are allocated with __signal_safe_memalign, // which is an internal function that wraps a mmap call, neither of which // we can intercept. Luckily, __signal_safe_memalign has a simple parseable // header which we can use. // //===----------------------------------------------------------------------===// #ifndef SANITIZER_TLS_GET_ADDR_H #define SANITIZER_TLS_GET_ADDR_H #include "sanitizer_common.h" namespace __sanitizer { struct DTLS { // Array of DTLS chunks for the current Thread. // If beg == 0, the chunk is unused. struct DTV { uptr beg, size; }; uptr dtv_size; DTV *dtv; // dtv_size elements, allocated by MmapOrDie. // Auxiliary fields, don't access them outside sanitizer_tls_get_addr.cpp uptr last_memalign_size; uptr last_memalign_ptr; }; // Returns pointer and size of a linker-allocated TLS block. // Each block is returned exactly once. DTLS::DTV *DTLS_on_tls_get_addr(void *arg, void *res, uptr static_tls_begin, uptr static_tls_end); void DTLS_on_libc_memalign(void *ptr, uptr size); DTLS *DTLS_Get(); void DTLS_Destroy(); // Make sure to call this before the thread is destroyed. // Returns true if DTLS of suspended thread is in destruction process. bool DTLSInDestruction(DTLS *dtls); } // namespace __sanitizer #endif // SANITIZER_TLS_GET_ADDR_H |