]>
Commit | Line | Data |
---|---|---|
7d752f28 | 1 | //===-- sanitizer_tls_get_addr.h --------------------------------*- C++ -*-===// |
2 | // | |
3 | // This file is distributed under the University of Illinois Open Source | |
4 | // License. See LICENSE.TXT for details. | |
5 | // | |
6 | //===----------------------------------------------------------------------===// | |
7 | // | |
8 | // Handle the __tls_get_addr call. | |
9 | // | |
10 | // All this magic is specific to glibc and is required to workaround | |
11 | // the lack of interface that would tell us about the Dynamic TLS (DTLS). | |
12 | // https://sourceware.org/bugzilla/show_bug.cgi?id=16291 | |
13 | // | |
14 | // The matters get worse because the glibc implementation changed between | |
15 | // 2.18 and 2.19: | |
16 | // https://groups.google.com/forum/#!topic/address-sanitizer/BfwYD8HMxTM | |
17 | // | |
18 | // Before 2.19, every DTLS chunk is allocated with __libc_memalign, | |
19 | // which we intercept and thus know where is the DTLS. | |
20 | // Since 2.19, DTLS chunks are allocated with __signal_safe_memalign, | |
21 | // which is an internal function that wraps a mmap call, neither of which | |
22 | // we can intercept. Luckily, __signal_safe_memalign has a simple parseable | |
23 | // header which we can use. | |
24 | // | |
25 | //===----------------------------------------------------------------------===// | |
26 | ||
27 | #ifndef SANITIZER_TLS_GET_ADDR_H | |
28 | #define SANITIZER_TLS_GET_ADDR_H | |
29 | ||
30 | #include "sanitizer_common.h" | |
31 | ||
32 | namespace __sanitizer { | |
33 | ||
34 | struct DTLS { | |
35 | // Array of DTLS chunks for the current Thread. | |
36 | // If beg == 0, the chunk is unused. | |
37 | struct DTV { | |
38 | uptr beg, size; | |
39 | }; | |
40 | ||
41 | uptr dtv_size; | |
42 | DTV *dtv; // dtv_size elements, allocated by MmapOrDie. | |
43 | ||
44 | // Auxiliary fields, don't access them outside sanitizer_tls_get_addr.cc | |
45 | uptr last_memalign_size; | |
46 | uptr last_memalign_ptr; | |
47 | }; | |
48 | ||
a9586c9c | 49 | // Returns pointer and size of a linker-allocated TLS block. |
50 | // Each block is returned exactly once. | |
5645a48f | 51 | DTLS::DTV *DTLS_on_tls_get_addr(void *arg, void *res, uptr static_tls_begin, |
52 | uptr static_tls_end); | |
7d752f28 | 53 | void DTLS_on_libc_memalign(void *ptr, uptr size); |
54 | DTLS *DTLS_Get(); | |
55 | void DTLS_Destroy(); // Make sure to call this before the thread is destroyed. | |
36093749 | 56 | // Returns true if DTLS of suspended thread is in destruction process. |
57 | bool DTLSInDestruction(DTLS *dtls); | |
7d752f28 | 58 | |
59 | } // namespace __sanitizer | |
60 | ||
61 | #endif // SANITIZER_TLS_GET_ADDR_H |