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//===-- asan_linux.cc -----------------------------------------------------===//
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file is a part of AddressSanitizer, an address sanity checker.
//
// Posix-specific details.
//===----------------------------------------------------------------------===//
#if defined(__linux__) || defined(__APPLE__)
#include "asan_internal.h"
#include "asan_interceptors.h"
#include "asan_mapping.h"
#include "asan_report.h"
#include "asan_stack.h"
#include "asan_thread_registry.h"
#include "sanitizer_common/sanitizer_libc.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>
static const uptr kAltStackSize = SIGSTKSZ * 4; // SIGSTKSZ is not enough.
namespace __asan {
static void MaybeInstallSigaction(int signum,
void (*handler)(int, siginfo_t *, void *)) {
if (!AsanInterceptsSignal(signum))
return;
struct sigaction sigact;
REAL(memset)(&sigact, 0, sizeof(sigact));
sigact.sa_sigaction = handler;
sigact.sa_flags = SA_SIGINFO;
if (flags()->use_sigaltstack) sigact.sa_flags |= SA_ONSTACK;
CHECK(0 == REAL(sigaction)(signum, &sigact, 0));
if (flags()->verbosity >= 1) {
Report("Installed the sigaction for signal %d\n", signum);
}
}
static void ASAN_OnSIGSEGV(int, siginfo_t *siginfo, void *context) {
uptr addr = (uptr)siginfo->si_addr;
// Write the first message using the bullet-proof write.
if (13 != internal_write(2, "ASAN:SIGSEGV\n", 13)) Die();
uptr pc, sp, bp;
GetPcSpBp(context, &pc, &sp, &bp);
ReportSIGSEGV(pc, sp, bp, addr);
}
void SetAlternateSignalStack() {
stack_t altstack, oldstack;
CHECK(0 == sigaltstack(0, &oldstack));
// If the alternate stack is already in place, do nothing.
if ((oldstack.ss_flags & SS_DISABLE) == 0) return;
// TODO(glider): the mapped stack should have the MAP_STACK flag in the
// future. It is not required by man 2 sigaltstack now (they're using
// malloc()).
void* base = MmapOrDie(kAltStackSize, __FUNCTION__);
altstack.ss_sp = base;
altstack.ss_flags = 0;
altstack.ss_size = kAltStackSize;
CHECK(0 == sigaltstack(&altstack, 0));
if (flags()->verbosity > 0) {
Report("Alternative stack for T%d set: [%p,%p)\n",
asanThreadRegistry().GetCurrentTidOrInvalid(),
altstack.ss_sp, (char*)altstack.ss_sp + altstack.ss_size);
}
}
void UnsetAlternateSignalStack() {
stack_t altstack, oldstack;
altstack.ss_sp = 0;
altstack.ss_flags = SS_DISABLE;
altstack.ss_size = 0;
CHECK(0 == sigaltstack(&altstack, &oldstack));
UnmapOrDie(oldstack.ss_sp, oldstack.ss_size);
}
void InstallSignalHandlers() {
// Set the alternate signal stack for the main thread.
// This will cause SetAlternateSignalStack to be called twice, but the stack
// will be actually set only once.
if (flags()->use_sigaltstack) SetAlternateSignalStack();
MaybeInstallSigaction(SIGSEGV, ASAN_OnSIGSEGV);
MaybeInstallSigaction(SIGBUS, ASAN_OnSIGSEGV);
}
// ---------------------- TSD ---------------- {{{1
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(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);
}
} // namespace __asan
#endif // __linux__ || __APPLE_
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