520 lines
16 KiB
C++
520 lines
16 KiB
C++
//===-- sanitizer_linux_libcdep.cc ----------------------------------------===//
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//
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// The LLVM Compiler Infrastructure
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//
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// This file is distributed under the University of Illinois Open Source
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// License. See LICENSE.TXT for details.
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//
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//===----------------------------------------------------------------------===//
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//
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// This file is shared between AddressSanitizer and ThreadSanitizer
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// run-time libraries and implements linux-specific functions from
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// sanitizer_libc.h.
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//===----------------------------------------------------------------------===//
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#include "sanitizer_platform.h"
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#if SANITIZER_FREEBSD || SANITIZER_LINUX
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#include "sanitizer_common.h"
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#include "sanitizer_flags.h"
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#include "sanitizer_freebsd.h"
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#include "sanitizer_linux.h"
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#include "sanitizer_placement_new.h"
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#include "sanitizer_procmaps.h"
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#include "sanitizer_stacktrace.h"
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#include "sanitizer_atomic.h"
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#include "sanitizer_symbolizer.h"
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#if SANITIZER_ANDROID || SANITIZER_FREEBSD
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#include <dlfcn.h> // for dlsym()
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#endif
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#include <pthread.h>
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#include <signal.h>
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#include <sys/resource.h>
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#if SANITIZER_FREEBSD
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#include <pthread_np.h>
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#include <osreldate.h>
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#define pthread_getattr_np pthread_attr_get_np
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#endif
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#if SANITIZER_LINUX
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#include <sys/prctl.h>
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#endif
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#if !SANITIZER_ANDROID
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#include <elf.h>
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#include <link.h>
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#include <unistd.h>
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#endif
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namespace __sanitizer {
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// This function is defined elsewhere if we intercepted pthread_attr_getstack.
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extern "C" {
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SANITIZER_WEAK_ATTRIBUTE int
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real_pthread_attr_getstack(void *attr, void **addr, size_t *size);
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} // extern "C"
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static int my_pthread_attr_getstack(void *attr, void **addr, size_t *size) {
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#if !SANITIZER_GO
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if (&real_pthread_attr_getstack)
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return real_pthread_attr_getstack((pthread_attr_t *)attr, addr, size);
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#endif
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return pthread_attr_getstack((pthread_attr_t *)attr, addr, size);
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}
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SANITIZER_WEAK_ATTRIBUTE int
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real_sigaction(int signum, const void *act, void *oldact);
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int internal_sigaction(int signum, const void *act, void *oldact) {
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#if !SANITIZER_GO
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if (&real_sigaction)
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return real_sigaction(signum, act, oldact);
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#endif
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return sigaction(signum, (const struct sigaction *)act,
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(struct sigaction *)oldact);
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}
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void GetThreadStackTopAndBottom(bool at_initialization, uptr *stack_top,
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uptr *stack_bottom) {
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CHECK(stack_top);
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CHECK(stack_bottom);
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if (at_initialization) {
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// This is the main thread. Libpthread may not be initialized yet.
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struct rlimit rl;
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CHECK_EQ(getrlimit(RLIMIT_STACK, &rl), 0);
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// Find the mapping that contains a stack variable.
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MemoryMappingLayout proc_maps(/*cache_enabled*/true);
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uptr start, end, offset;
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uptr prev_end = 0;
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while (proc_maps.Next(&start, &end, &offset, 0, 0, /* protection */0)) {
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if ((uptr)&rl < end)
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break;
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prev_end = end;
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}
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CHECK((uptr)&rl >= start && (uptr)&rl < end);
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// Get stacksize from rlimit, but clip it so that it does not overlap
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// with other mappings.
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uptr stacksize = rl.rlim_cur;
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if (stacksize > end - prev_end)
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stacksize = end - prev_end;
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// When running with unlimited stack size, we still want to set some limit.
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// The unlimited stack size is caused by 'ulimit -s unlimited'.
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// Also, for some reason, GNU make spawns subprocesses with unlimited stack.
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if (stacksize > kMaxThreadStackSize)
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stacksize = kMaxThreadStackSize;
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*stack_top = end;
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*stack_bottom = end - stacksize;
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return;
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}
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pthread_attr_t attr;
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pthread_attr_init(&attr);
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CHECK_EQ(pthread_getattr_np(pthread_self(), &attr), 0);
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uptr stacksize = 0;
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void *stackaddr = 0;
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my_pthread_attr_getstack(&attr, &stackaddr, (size_t*)&stacksize);
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pthread_attr_destroy(&attr);
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CHECK_LE(stacksize, kMaxThreadStackSize); // Sanity check.
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*stack_top = (uptr)stackaddr + stacksize;
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*stack_bottom = (uptr)stackaddr;
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}
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#if !SANITIZER_GO
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bool SetEnv(const char *name, const char *value) {
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void *f = dlsym(RTLD_NEXT, "setenv");
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if (f == 0)
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return false;
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typedef int(*setenv_ft)(const char *name, const char *value, int overwrite);
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setenv_ft setenv_f;
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CHECK_EQ(sizeof(setenv_f), sizeof(f));
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internal_memcpy(&setenv_f, &f, sizeof(f));
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return setenv_f(name, value, 1) == 0;
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}
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#endif
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bool SanitizerSetThreadName(const char *name) {
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#ifdef PR_SET_NAME
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return 0 == prctl(PR_SET_NAME, (unsigned long)name, 0, 0, 0); // NOLINT
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#else
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return false;
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#endif
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}
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bool SanitizerGetThreadName(char *name, int max_len) {
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#ifdef PR_GET_NAME
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char buff[17];
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if (prctl(PR_GET_NAME, (unsigned long)buff, 0, 0, 0)) // NOLINT
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return false;
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internal_strncpy(name, buff, max_len);
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name[max_len] = 0;
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return true;
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#else
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return false;
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#endif
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}
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#if !SANITIZER_FREEBSD
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static uptr g_tls_size;
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#endif
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#ifdef __i386__
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# define DL_INTERNAL_FUNCTION __attribute__((regparm(3), stdcall))
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#else
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# define DL_INTERNAL_FUNCTION
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#endif
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#if defined(__mips__)
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// TlsPreTcbSize includes size of struct pthread_descr and size of tcb
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// head structure. It lies before the static tls blocks.
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static uptr TlsPreTcbSize() {
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const uptr kTcbHead = 16;
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const uptr kTlsAlign = 16;
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const uptr kTlsPreTcbSize =
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(ThreadDescriptorSize() + kTcbHead + kTlsAlign - 1) & ~(kTlsAlign - 1);
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InitTlsSize();
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g_tls_size = (g_tls_size + kTlsPreTcbSize + kTlsAlign -1) & ~(kTlsAlign - 1);
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return kTlsPreTcbSize;
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}
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#endif
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void InitTlsSize() {
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#if !SANITIZER_FREEBSD && !SANITIZER_ANDROID && !SANITIZER_GO
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typedef void (*get_tls_func)(size_t*, size_t*) DL_INTERNAL_FUNCTION;
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get_tls_func get_tls;
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void *get_tls_static_info_ptr = dlsym(RTLD_NEXT, "_dl_get_tls_static_info");
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CHECK_EQ(sizeof(get_tls), sizeof(get_tls_static_info_ptr));
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internal_memcpy(&get_tls, &get_tls_static_info_ptr,
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sizeof(get_tls_static_info_ptr));
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CHECK_NE(get_tls, 0);
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size_t tls_size = 0;
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size_t tls_align = 0;
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get_tls(&tls_size, &tls_align);
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g_tls_size = tls_size;
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#endif // !SANITIZER_FREEBSD && !SANITIZER_ANDROID
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}
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#if (defined(__x86_64__) || defined(__i386__) || defined(__mips__)) \
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&& SANITIZER_LINUX
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// sizeof(struct thread) from glibc.
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static atomic_uintptr_t kThreadDescriptorSize;
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uptr ThreadDescriptorSize() {
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uptr val = atomic_load(&kThreadDescriptorSize, memory_order_relaxed);
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if (val)
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return val;
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#if defined(__x86_64__) || defined(__i386__)
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#ifdef _CS_GNU_LIBC_VERSION
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char buf[64];
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uptr len = confstr(_CS_GNU_LIBC_VERSION, buf, sizeof(buf));
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if (len < sizeof(buf) && internal_strncmp(buf, "glibc 2.", 8) == 0) {
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char *end;
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int minor = internal_simple_strtoll(buf + 8, &end, 10);
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if (end != buf + 8 && (*end == '\0' || *end == '.')) {
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/* sizeof(struct thread) values from various glibc versions. */
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if (SANITIZER_X32)
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val = 1728; // Assume only one particular version for x32.
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else if (minor <= 3)
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val = FIRST_32_SECOND_64(1104, 1696);
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else if (minor == 4)
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val = FIRST_32_SECOND_64(1120, 1728);
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else if (minor == 5)
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val = FIRST_32_SECOND_64(1136, 1728);
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else if (minor <= 9)
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val = FIRST_32_SECOND_64(1136, 1712);
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else if (minor == 10)
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val = FIRST_32_SECOND_64(1168, 1776);
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else if (minor <= 12)
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val = FIRST_32_SECOND_64(1168, 2288);
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else if (minor == 13)
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val = FIRST_32_SECOND_64(1168, 2304);
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else
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val = FIRST_32_SECOND_64(1216, 2304);
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}
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if (val)
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atomic_store(&kThreadDescriptorSize, val, memory_order_relaxed);
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return val;
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}
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#endif
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#elif defined(__mips__)
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// TODO(sagarthakur): add more values as per different glibc versions.
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val = FIRST_32_SECOND_64(1152, 1776);
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if (val)
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atomic_store(&kThreadDescriptorSize, val, memory_order_relaxed);
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return val;
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#endif
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return 0;
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}
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// The offset at which pointer to self is located in the thread descriptor.
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const uptr kThreadSelfOffset = FIRST_32_SECOND_64(8, 16);
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uptr ThreadSelfOffset() {
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return kThreadSelfOffset;
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}
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uptr ThreadSelf() {
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uptr descr_addr;
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# if defined(__i386__)
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asm("mov %%gs:%c1,%0" : "=r"(descr_addr) : "i"(kThreadSelfOffset));
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# elif defined(__x86_64__)
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asm("mov %%fs:%c1,%0" : "=r"(descr_addr) : "i"(kThreadSelfOffset));
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# elif defined(__mips__)
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// MIPS uses TLS variant I. The thread pointer (in hardware register $29)
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// points to the end of the TCB + 0x7000. The pthread_descr structure is
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// immediately in front of the TCB. TlsPreTcbSize() includes the size of the
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// TCB and the size of pthread_descr.
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const uptr kTlsTcbOffset = 0x7000;
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uptr thread_pointer;
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asm volatile(".set push;\
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.set mips64r2;\
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rdhwr %0,$29;\
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.set pop" : "=r" (thread_pointer));
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descr_addr = thread_pointer - kTlsTcbOffset - TlsPreTcbSize();
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# else
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# error "unsupported CPU arch"
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# endif
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return descr_addr;
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}
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#endif // (x86_64 || i386 || MIPS) && SANITIZER_LINUX
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#if SANITIZER_FREEBSD
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static void **ThreadSelfSegbase() {
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void **segbase = 0;
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# if defined(__i386__)
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// sysarch(I386_GET_GSBASE, segbase);
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__asm __volatile("mov %%gs:0, %0" : "=r" (segbase));
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# elif defined(__x86_64__)
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// sysarch(AMD64_GET_FSBASE, segbase);
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__asm __volatile("movq %%fs:0, %0" : "=r" (segbase));
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# else
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# error "unsupported CPU arch for FreeBSD platform"
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# endif
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return segbase;
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}
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uptr ThreadSelf() {
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return (uptr)ThreadSelfSegbase()[2];
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}
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#endif // SANITIZER_FREEBSD
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#if !SANITIZER_GO
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static void GetTls(uptr *addr, uptr *size) {
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#if SANITIZER_LINUX
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# if defined(__x86_64__) || defined(__i386__)
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*addr = ThreadSelf();
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*size = GetTlsSize();
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*addr -= *size;
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*addr += ThreadDescriptorSize();
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# elif defined(__mips__)
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*addr = ThreadSelf();
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*size = GetTlsSize();
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# else
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*addr = 0;
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*size = 0;
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# endif
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#elif SANITIZER_FREEBSD
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void** segbase = ThreadSelfSegbase();
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*addr = 0;
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*size = 0;
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if (segbase != 0) {
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// tcbalign = 16
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// tls_size = round(tls_static_space, tcbalign);
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// dtv = segbase[1];
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// dtv[2] = segbase - tls_static_space;
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void **dtv = (void**) segbase[1];
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*addr = (uptr) dtv[2];
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*size = (*addr == 0) ? 0 : ((uptr) segbase[0] - (uptr) dtv[2]);
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}
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#else
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# error "Unknown OS"
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#endif
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}
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#endif
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#if !SANITIZER_GO
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uptr GetTlsSize() {
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#if SANITIZER_FREEBSD
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uptr addr, size;
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GetTls(&addr, &size);
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return size;
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#else
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return g_tls_size;
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#endif
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}
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#endif
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void GetThreadStackAndTls(bool main, uptr *stk_addr, uptr *stk_size,
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uptr *tls_addr, uptr *tls_size) {
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#if SANITIZER_GO
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// Stub implementation for Go.
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*stk_addr = *stk_size = *tls_addr = *tls_size = 0;
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#else
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GetTls(tls_addr, tls_size);
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uptr stack_top, stack_bottom;
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GetThreadStackTopAndBottom(main, &stack_top, &stack_bottom);
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*stk_addr = stack_bottom;
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*stk_size = stack_top - stack_bottom;
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if (!main) {
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// If stack and tls intersect, make them non-intersecting.
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if (*tls_addr > *stk_addr && *tls_addr < *stk_addr + *stk_size) {
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CHECK_GT(*tls_addr + *tls_size, *stk_addr);
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CHECK_LE(*tls_addr + *tls_size, *stk_addr + *stk_size);
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*stk_size -= *tls_size;
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*tls_addr = *stk_addr + *stk_size;
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}
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}
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#endif
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}
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void AdjustStackSize(void *attr_) {
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pthread_attr_t *attr = (pthread_attr_t *)attr_;
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uptr stackaddr = 0;
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size_t stacksize = 0;
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my_pthread_attr_getstack(attr, (void**)&stackaddr, &stacksize);
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// GLibC will return (0 - stacksize) as the stack address in the case when
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// stacksize is set, but stackaddr is not.
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bool stack_set = (stackaddr != 0) && (stackaddr + stacksize != 0);
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// We place a lot of tool data into TLS, account for that.
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const uptr minstacksize = GetTlsSize() + 128*1024;
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if (stacksize < minstacksize) {
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if (!stack_set) {
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if (stacksize != 0) {
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VPrintf(1, "Sanitizer: increasing stacksize %zu->%zu\n", stacksize,
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minstacksize);
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pthread_attr_setstacksize(attr, minstacksize);
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}
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} else {
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Printf("Sanitizer: pre-allocated stack size is insufficient: "
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"%zu < %zu\n", stacksize, minstacksize);
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Printf("Sanitizer: pthread_create is likely to fail.\n");
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}
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}
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}
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#if SANITIZER_ANDROID
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uptr GetListOfModules(LoadedModule *modules, uptr max_modules,
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string_predicate_t filter) {
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MemoryMappingLayout memory_mapping(false);
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return memory_mapping.DumpListOfModules(modules, max_modules, filter);
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}
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#else // SANITIZER_ANDROID
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# if !SANITIZER_FREEBSD
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typedef ElfW(Phdr) Elf_Phdr;
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# elif SANITIZER_WORDSIZE == 32 && __FreeBSD_version <= 902001 // v9.2
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# define Elf_Phdr XElf32_Phdr
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# define dl_phdr_info xdl_phdr_info
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# define dl_iterate_phdr(c, b) xdl_iterate_phdr((c), (b))
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# endif
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struct DlIteratePhdrData {
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LoadedModule *modules;
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uptr current_n;
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bool first;
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uptr max_n;
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string_predicate_t filter;
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};
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static int dl_iterate_phdr_cb(dl_phdr_info *info, size_t size, void *arg) {
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DlIteratePhdrData *data = (DlIteratePhdrData*)arg;
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if (data->current_n == data->max_n)
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return 0;
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InternalScopedString module_name(kMaxPathLength);
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if (data->first) {
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data->first = false;
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// First module is the binary itself.
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ReadBinaryName(module_name.data(), module_name.size());
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} else if (info->dlpi_name) {
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module_name.append("%s", info->dlpi_name);
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}
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if (module_name[0] == '\0')
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return 0;
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if (data->filter && !data->filter(module_name.data()))
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return 0;
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void *mem = &data->modules[data->current_n];
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LoadedModule *cur_module = new(mem) LoadedModule(module_name.data(),
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info->dlpi_addr);
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data->current_n++;
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for (int i = 0; i < info->dlpi_phnum; i++) {
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const Elf_Phdr *phdr = &info->dlpi_phdr[i];
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if (phdr->p_type == PT_LOAD) {
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uptr cur_beg = info->dlpi_addr + phdr->p_vaddr;
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uptr cur_end = cur_beg + phdr->p_memsz;
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bool executable = phdr->p_flags & PF_X;
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cur_module->addAddressRange(cur_beg, cur_end, executable);
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}
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}
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return 0;
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}
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uptr GetListOfModules(LoadedModule *modules, uptr max_modules,
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string_predicate_t filter) {
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CHECK(modules);
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DlIteratePhdrData data = {modules, 0, true, max_modules, filter};
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dl_iterate_phdr(dl_iterate_phdr_cb, &data);
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return data.current_n;
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}
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#endif // SANITIZER_ANDROID
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void PrepareForSandboxing(__sanitizer_sandbox_arguments *args) {
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// Some kinds of sandboxes may forbid filesystem access, so we won't be able
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// to read the file mappings from /proc/self/maps. Luckily, neither the
|
|
// process will be able to load additional libraries, so it's fine to use the
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|
// cached mappings.
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|
MemoryMappingLayout::CacheMemoryMappings();
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|
// Same for /proc/self/exe in the symbolizer.
|
|
#if !SANITIZER_GO
|
|
Symbolizer::GetOrInit()->PrepareForSandboxing();
|
|
CovPrepareForSandboxing(args);
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|
#endif
|
|
}
|
|
|
|
// getrusage does not give us the current RSS, only the max RSS.
|
|
// Still, this is better than nothing if /proc/self/statm is not available
|
|
// for some reason, e.g. due to a sandbox.
|
|
static uptr GetRSSFromGetrusage() {
|
|
struct rusage usage;
|
|
if (getrusage(RUSAGE_SELF, &usage)) // Failed, probably due to a sandbox.
|
|
return 0;
|
|
return usage.ru_maxrss << 10; // ru_maxrss is in Kb.
|
|
}
|
|
|
|
uptr GetRSS() {
|
|
if (!common_flags()->can_use_proc_maps_statm)
|
|
return GetRSSFromGetrusage();
|
|
uptr fd = OpenFile("/proc/self/statm", false);
|
|
if ((sptr)fd < 0)
|
|
return GetRSSFromGetrusage();
|
|
char buf[64];
|
|
uptr len = internal_read(fd, buf, sizeof(buf) - 1);
|
|
internal_close(fd);
|
|
if ((sptr)len <= 0)
|
|
return 0;
|
|
buf[len] = 0;
|
|
// The format of the file is:
|
|
// 1084 89 69 11 0 79 0
|
|
// We need the second number which is RSS in pages.
|
|
char *pos = buf;
|
|
// Skip the first number.
|
|
while (*pos >= '0' && *pos <= '9')
|
|
pos++;
|
|
// Skip whitespaces.
|
|
while (!(*pos >= '0' && *pos <= '9') && *pos != 0)
|
|
pos++;
|
|
// Read the number.
|
|
uptr rss = 0;
|
|
while (*pos >= '0' && *pos <= '9')
|
|
rss = rss * 10 + *pos++ - '0';
|
|
return rss * GetPageSizeCached();
|
|
}
|
|
|
|
} // namespace __sanitizer
|
|
|
|
#endif // SANITIZER_FREEBSD || SANITIZER_LINUX
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