1 //===-- asan_posix.cc -----------------------------------------------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file is a part of AddressSanitizer, an address sanity checker.
12 // Posix-specific details.
13 //===----------------------------------------------------------------------===//
15 #include "sanitizer_common/sanitizer_platform.h"
18 #include "asan_internal.h"
19 #include "asan_interceptors.h"
20 #include "asan_mapping.h"
21 #include "asan_report.h"
22 #include "asan_stack.h"
23 #include "sanitizer_common/sanitizer_libc.h"
24 #include "sanitizer_common/sanitizer_posix.h"
25 #include "sanitizer_common/sanitizer_procmaps.h"
31 #include <sys/resource.h>
36 void AsanOnDeadlySignal(int signo, void *siginfo, void *context) {
37 ScopedDeadlySignal signal_scope(GetCurrentThread());
38 int code = (int)((siginfo_t*)siginfo)->si_code;
39 // Write the first message using the bullet-proof write.
40 if (18 != internal_write(2, "ASAN:DEADLYSIGNAL\n", 18)) Die();
41 SignalContext sig = SignalContext::Create(siginfo, context);
43 // Access at a reasonable offset above SP, or slightly below it (to account
44 // for x86_64 or PowerPC redzone, ARM push of multiple registers, etc) is
45 // probably a stack overflow.
46 bool IsStackAccess = sig.addr + 512 > sig.sp && sig.addr < sig.sp + 0xFFFF;
49 // Large stack frames can be allocated with e.g.
51 // stdux r1,r1,r0 # store sp to [sp-10000] and update sp by -10000
52 // If the store faults then sp will not have been updated, so test above
53 // will not work, becase the fault address will be more than just "slightly"
55 if (!IsStackAccess && IsAccessibleMemoryRange(sig.pc, 4)) {
56 u32 inst = *(unsigned *)sig.pc;
57 u32 ra = (inst >> 16) & 0x1F;
58 u32 opcd = inst >> 26;
59 u32 xo = (inst >> 1) & 0x3FF;
60 // Check for store-with-update to sp. The instructions we accept are:
61 // stbu rs,d(ra) stbux rs,ra,rb
62 // sthu rs,d(ra) sthux rs,ra,rb
63 // stwu rs,d(ra) stwux rs,ra,rb
64 // stdu rs,ds(ra) stdux rs,ra,rb
65 // where ra is r1 (the stack pointer).
67 (opcd == 39 || opcd == 45 || opcd == 37 || opcd == 62 ||
68 (opcd == 31 && (xo == 247 || xo == 439 || xo == 183 || xo == 181))))
73 // We also check si_code to filter out SEGV caused by something else other
74 // then hitting the guard page or unmapped memory, like, for example,
75 // unaligned memory access.
76 if (IsStackAccess && (code == si_SEGV_MAPERR || code == si_SEGV_ACCERR))
77 ReportStackOverflow(sig);
78 else if (signo == SIGFPE)
79 ReportDeadlySignal("FPE", sig);
80 else if (signo == SIGILL)
81 ReportDeadlySignal("ILL", sig);
83 ReportDeadlySignal("SEGV", sig);
86 // ---------------------- TSD ---------------- {{{1
88 static pthread_key_t tsd_key;
89 static bool tsd_key_inited = false;
90 void AsanTSDInit(void (*destructor)(void *tsd)) {
91 CHECK(!tsd_key_inited);
92 tsd_key_inited = true;
93 CHECK_EQ(0, pthread_key_create(&tsd_key, destructor));
97 CHECK(tsd_key_inited);
98 return pthread_getspecific(tsd_key);
101 void AsanTSDSet(void *tsd) {
102 CHECK(tsd_key_inited);
103 pthread_setspecific(tsd_key, tsd);
106 void PlatformTSDDtor(void *tsd) {
107 AsanThreadContext *context = (AsanThreadContext*)tsd;
108 if (context->destructor_iterations > 1) {
109 context->destructor_iterations--;
110 CHECK_EQ(0, pthread_setspecific(tsd_key, tsd));
113 AsanThread::TSDDtor(tsd);
115 } // namespace __asan
117 #endif // SANITIZER_POSIX