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//===-- asan_posix.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 AddressSanitizer, an address sanity checker.
//
// Posix-specific details.
//===----------------------------------------------------------------------===//
#include "sanitizer_common/sanitizer_platform.h"
#if SANITIZER_POSIX
#include "asan_internal.h"
#include "asan_interceptors.h"
#include "asan_mapping.h"
#include "asan_poisoning.h"
#include "asan_report.h"
#include "asan_stack.h"
#include "sanitizer_common/sanitizer_libc.h"
#include "sanitizer_common/sanitizer_posix.h"
#include "sanitizer_common/sanitizer_procmaps.h"
#include <pthread.h>
#include <signal.h>
#include <stdlib.h>
#include <sys/time.h>
#include <sys/resource.h>
#include <unistd.h>
namespace __asan {
void AsanOnDeadlySignal(int signo, void *siginfo, void *context) {
StartReportDeadlySignal();
SignalContext sig(siginfo, context);
ReportDeadlySignal(sig);
}
bool PlatformUnpoisonStacks() {
stack_t signal_stack;
CHECK_EQ(0, sigaltstack(nullptr, &signal_stack));
uptr sigalt_bottom = (uptr)signal_stack.ss_sp;
uptr sigalt_top = (uptr)((char *)signal_stack.ss_sp + signal_stack.ss_size);
// If we're executing on the signal alternate stack AND the Linux flag
// SS_AUTODISARM was used, then we cannot get the signal alternate stack
// bounds from sigaltstack -- sigaltstack's output looks just as if no
// alternate stack has ever been set up.
// We're always unpoisoning the signal alternate stack to support jumping
// between the default stack and signal alternate stack.
if (signal_stack.ss_flags != SS_DISABLE)
UnpoisonStack(sigalt_bottom, sigalt_top, "sigalt");
if (signal_stack.ss_flags != SS_ONSTACK)
return false;
// Since we're on the signal alternate stack, we cannot find the DEFAULT
// stack bottom using a local variable.
uptr default_bottom, tls_addr, tls_size, stack_size;
GetThreadStackAndTls(/*main=*/false, &default_bottom, &stack_size, &tls_addr,
&tls_size);
UnpoisonStack(default_bottom, default_bottom + stack_size, "default");
return true;
}
// ---------------------- TSD ---------------- {{{1
#if SANITIZER_NETBSD && !ASAN_DYNAMIC
// Thread Static Data cannot be used in early static ASan init on NetBSD.
// Reuse the Asan TSD API for compatibility with existing code
// with an alternative implementation.
static void (*tsd_destructor)(void *tsd) = nullptr;
struct tsd_key {
tsd_key() : key(nullptr) {}
~tsd_key() {
CHECK(tsd_destructor);
if (key)
(*tsd_destructor)(key);
}
void *key;
};
static thread_local struct tsd_key key;
void AsanTSDInit(void (*destructor)(void *tsd)) {
CHECK(!tsd_destructor);
tsd_destructor = destructor;
}
void *AsanTSDGet() {
CHECK(tsd_destructor);
return key.key;
}
void AsanTSDSet(void *tsd) {
CHECK(tsd_destructor);
CHECK(tsd);
CHECK(!key.key);
key.key = tsd;
}
void PlatformTSDDtor(void *tsd) {
CHECK(tsd_destructor);
CHECK_EQ(key.key, tsd);
key.key = nullptr;
// Make sure that signal handler can not see a stale current thread pointer.
atomic_signal_fence(memory_order_seq_cst);
AsanThread::TSDDtor(tsd);
}
#else
static pthread_key_t tsd_key;
static bool tsd_key_inited = false;
void AsanTSDInit(void (*destructor)(void *tsd)) {
CHECK(!tsd_key_inited);
tsd_key_inited = true;
CHECK_EQ(0, pthread_key_create(&tsd_key, destructor));
}
void *AsanTSDGet() {
CHECK(tsd_key_inited);
return pthread_getspecific(tsd_key);
}
void AsanTSDSet(void *tsd) {
CHECK(tsd_key_inited);
pthread_setspecific(tsd_key, tsd);
}
void PlatformTSDDtor(void *tsd) {
AsanThreadContext *context = (AsanThreadContext*)tsd;
if (context->destructor_iterations > 1) {
context->destructor_iterations--;
CHECK_EQ(0, pthread_setspecific(tsd_key, tsd));
return;
}
AsanThread::TSDDtor(tsd);
}
#endif
} // namespace __asan
#endif // SANITIZER_POSIX
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