libsanitizer/sanitizer_common/sanitizer_common_libcdep.cpp

   1 //===-- sanitizer_common_libcdep.cpp --------------------------------------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8 //
   9 // This file is shared between AddressSanitizer and ThreadSanitizer
  10 // run-time libraries.
  11 //===----------------------------------------------------------------------===//
  12
  13 #include "sanitizer_allocator.h"
  14 #include "sanitizer_allocator_interface.h"
  15 #include "sanitizer_common.h"
  16 #include "sanitizer_flags.h"
  17 #include "sanitizer_interface_internal.h"
  18 #include "sanitizer_procmaps.h"
  19 #include "sanitizer_stackdepot.h"
  20
  21 namespace __sanitizer {
  22
  23 #if (SANITIZER_LINUX || SANITIZER_NETBSD) && !SANITIZER_GO
  24 // Weak default implementation for when sanitizer_stackdepot is not linked in.
  25 SANITIZER_WEAK_ATTRIBUTE StackDepotStats StackDepotGetStats() { return {}; }
  26
  27 void *BackgroundThread(void *arg) {
  28   VPrintf(1, "%s: Started BackgroundThread\n", SanitizerToolName);
  29   const uptr hard_rss_limit_mb = common_flags()->hard_rss_limit_mb;
  30   const uptr soft_rss_limit_mb = common_flags()->soft_rss_limit_mb;
  31   const bool heap_profile = common_flags()->heap_profile;
  32   uptr prev_reported_rss = 0;
  33   uptr prev_reported_stack_depot_size = 0;
  34   bool reached_soft_rss_limit = false;
  35   uptr rss_during_last_reported_profile = 0;
  36   while (true) {
  37     SleepForMillis(100);
  38     const uptr current_rss_mb = GetRSS() >> 20;
  39     if (Verbosity()) {
  40       // If RSS has grown 10% since last time, print some information.
  41       if (prev_reported_rss * 11 / 10 < current_rss_mb) {
  42         Printf("%s: RSS: %zdMb\n", SanitizerToolName, current_rss_mb);
  43         prev_reported_rss = current_rss_mb;
  44       }
  45       // If stack depot has grown 10% since last time, print it too.
  46       StackDepotStats stack_depot_stats = StackDepotGetStats();
  47       if (prev_reported_stack_depot_size * 11 / 10 <
  48           stack_depot_stats.allocated) {
  49         Printf("%s: StackDepot: %zd ids; %zdM allocated\n", SanitizerToolName,
  50                stack_depot_stats.n_uniq_ids, stack_depot_stats.allocated >> 20);
  51         prev_reported_stack_depot_size = stack_depot_stats.allocated;
  52       }
  53     }
  54     // Check RSS against the limit.
  55     if (hard_rss_limit_mb && hard_rss_limit_mb < current_rss_mb) {
  56       Report("%s: hard rss limit exhausted (%zdMb vs %zdMb)\n",
  57              SanitizerToolName, hard_rss_limit_mb, current_rss_mb);
  58       DumpProcessMap();
  59       Die();
  60     }
  61     if (soft_rss_limit_mb) {
  62       if (soft_rss_limit_mb < current_rss_mb && !reached_soft_rss_limit) {
  63         reached_soft_rss_limit = true;
  64         Report("%s: soft rss limit exhausted (%zdMb vs %zdMb)\n",
  65                SanitizerToolName, soft_rss_limit_mb, current_rss_mb);
  66         SetRssLimitExceeded(true);
  67       } else if (soft_rss_limit_mb >= current_rss_mb &&
  68                  reached_soft_rss_limit) {
  69         reached_soft_rss_limit = false;
  70         SetRssLimitExceeded(false);
  71       }
  72     }
  73     if (heap_profile &&
  74         current_rss_mb > rss_during_last_reported_profile * 1.1) {
  75       Printf("\n\nHEAP PROFILE at RSS %zdMb\n", current_rss_mb);
  76       __sanitizer_print_memory_profile(90, 20);
  77       rss_during_last_reported_profile = current_rss_mb;
  78     }
  79   }
  80 }
  81
  82 void MaybeStartBackgroudThread() {
  83   // Need to implement/test on other platforms.
  84   // Start the background thread if one of the rss limits is given.
  85   if (!common_flags()->hard_rss_limit_mb &&
  86       !common_flags()->soft_rss_limit_mb &&
  87       !common_flags()->heap_profile) return;
  88   if (!&real_pthread_create) {
  89     VPrintf(1, "%s: real_pthread_create undefined\n", SanitizerToolName);
  90     return;  // Can't spawn the thread anyway.
  91   }
  92
  93   static bool started = false;
  94   if (!started) {
  95     started = true;
  96     internal_start_thread(BackgroundThread, nullptr);
  97   }
  98 }
  99
 100 #  if !SANITIZER_START_BACKGROUND_THREAD_IN_ASAN_INTERNAL
 101 #    ifdef __clang__
 102 #    pragma clang diagnostic push
 103 // We avoid global-constructors to be sure that globals are ready when
 104 // sanitizers need them. This can happend before global constructors executed.
 105 // Here we don't mind if thread is started on later stages.
 106 #    pragma clang diagnostic ignored "-Wglobal-constructors"
 107 #    endif
 108 static struct BackgroudThreadStarted {
 109   BackgroudThreadStarted() { MaybeStartBackgroudThread(); }
 110 } background_thread_strarter UNUSED;
 111 #    ifdef __clang__
 112 #    pragma clang diagnostic pop
 113 #    endif
 114 #  endif
 115 #else
 116 void MaybeStartBackgroudThread() {}
 117 #endif
 118
 119 void WriteToSyslog(const char *msg) {
 120   InternalScopedString msg_copy;
 121   msg_copy.append("%s", msg);
 122   const char *p = msg_copy.data();
 123
 124   // Print one line at a time.
 125   // syslog, at least on Android, has an implicit message length limit.
 126   while (char* q = internal_strchr(p, '\n')) {
 127     *q = '\0';
 128     WriteOneLineToSyslog(p);
 129     p = q + 1;
 130   }
 131   // Print remaining characters, if there are any.
 132   // Note that this will add an extra newline at the end.
 133   // FIXME: buffer extra output. This would need a thread-local buffer, which
 134   // on Android requires plugging into the tools (ex. ASan's) Thread class.
 135   if (*p)
 136     WriteOneLineToSyslog(p);
 137 }
 138
 139 static void (*sandboxing_callback)();
 140 void SetSandboxingCallback(void (*f)()) {
 141   sandboxing_callback = f;
 142 }
 143
 144 uptr ReservedAddressRange::InitAligned(uptr size, uptr align,
 145                                        const char *name) {
 146   CHECK(IsPowerOfTwo(align));
 147   if (align <= GetPageSizeCached())
 148     return Init(size, name);
 149   uptr start = Init(size + align, name);
 150   start += align - (start & (align - 1));
 151   return start;
 152 }
 153
 154 #if !SANITIZER_FUCHSIA
 155
 156 // Reserve memory range [beg, end].
 157 // We need to use inclusive range because end+1 may not be representable.
 158 void ReserveShadowMemoryRange(uptr beg, uptr end, const char *name,
 159                               bool madvise_shadow) {
 160   CHECK_EQ((beg % GetMmapGranularity()), 0);
 161   CHECK_EQ(((end + 1) % GetMmapGranularity()), 0);
 162   uptr size = end - beg + 1;
 163   DecreaseTotalMmap(size);  // Don't count the shadow against mmap_limit_mb.
 164   if (madvise_shadow ? !MmapFixedSuperNoReserve(beg, size, name)
 165                      : !MmapFixedNoReserve(beg, size, name)) {
 166     Report(
 167         "ReserveShadowMemoryRange failed while trying to map 0x%zx bytes. "
 168         "Perhaps you're using ulimit -v\n",
 169         size);
 170     Abort();
 171   }
 172   if (madvise_shadow && common_flags()->use_madv_dontdump)
 173     DontDumpShadowMemory(beg, size);
 174 }
 175
 176 void ProtectGap(uptr addr, uptr size, uptr zero_base_shadow_start,
 177                 uptr zero_base_max_shadow_start) {
 178   if (!size)
 179     return;
 180   void *res = MmapFixedNoAccess(addr, size, "shadow gap");
 181   if (addr == (uptr)res)
 182     return;
 183   // A few pages at the start of the address space can not be protected.
 184   // But we really want to protect as much as possible, to prevent this memory
 185   // being returned as a result of a non-FIXED mmap().
 186   if (addr == zero_base_shadow_start) {
 187     uptr step = GetMmapGranularity();
 188     while (size > step && addr < zero_base_max_shadow_start) {
 189       addr += step;
 190       size -= step;
 191       void *res = MmapFixedNoAccess(addr, size, "shadow gap");
 192       if (addr == (uptr)res)
 193         return;
 194     }
 195   }
 196
 197   Report(
 198       "ERROR: Failed to protect the shadow gap. "
 199       "%s cannot proceed correctly. ABORTING.\n",
 200       SanitizerToolName);
 201   DumpProcessMap();
 202   Die();
 203 }
 204
 205 #endif  // !SANITIZER_FUCHSIA
 206
 207 #if !SANITIZER_WINDOWS && !SANITIZER_GO
 208 // Weak default implementation for when sanitizer_stackdepot is not linked in.
 209 SANITIZER_WEAK_ATTRIBUTE void StackDepotStopBackgroundThread() {}
 210 static void StopStackDepotBackgroundThread() {
 211   StackDepotStopBackgroundThread();
 212 }
 213 #else
 214 // SANITIZER_WEAK_ATTRIBUTE is unsupported.
 215 static void StopStackDepotBackgroundThread() {}
 216 #endif
 217
 218 }  // namespace __sanitizer
 219
 220 SANITIZER_INTERFACE_WEAK_DEF(void, __sanitizer_sandbox_on_notify,
 221                              __sanitizer_sandbox_arguments *args) {
 222   __sanitizer::StopStackDepotBackgroundThread();
 223   __sanitizer::PlatformPrepareForSandboxing(args);
 224   if (__sanitizer::sandboxing_callback)
 225     __sanitizer::sandboxing_callback();
 226 }