lib/sanitizer_common/sanitizer_common_libcdep.cpp

//===-- sanitizer_common_libcdep.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 shared between AddressSanitizer and ThreadSanitizer
// run-time libraries.
//===----------------------------------------------------------------------===//

#include "sanitizer_allocator_interface.h"
#include "sanitizer_common.h"
#include "sanitizer_flags.h"
#include "sanitizer_procmaps.h"


namespace __sanitizer {

static void (*SoftRssLimitExceededCallback)(bool exceeded);
void SetSoftRssLimitExceededCallback(void (*Callback)(bool exceeded)) {
  CHECK_EQ(SoftRssLimitExceededCallback, nullptr);
  SoftRssLimitExceededCallback = Callback;
}

#if (SANITIZER_LINUX || SANITIZER_NETBSD) && !SANITIZER_GO
// Weak default implementation for when sanitizer_stackdepot is not linked in.
SANITIZER_WEAK_ATTRIBUTE StackDepotStats *StackDepotGetStats() {
  return nullptr;
}

void BackgroundThread(void *arg) {
  const uptr hard_rss_limit_mb = common_flags()->hard_rss_limit_mb;
  const uptr soft_rss_limit_mb = common_flags()->soft_rss_limit_mb;
  const bool heap_profile = common_flags()->heap_profile;
  uptr prev_reported_rss = 0;
  uptr prev_reported_stack_depot_size = 0;
  bool reached_soft_rss_limit = false;
  uptr rss_during_last_reported_profile = 0;
  while (true) {
    SleepForMillis(100);
    const uptr current_rss_mb = GetRSS() >> 20;
    if (Verbosity()) {
      // If RSS has grown 10% since last time, print some information.
      if (prev_reported_rss * 11 / 10 < current_rss_mb) {
        Printf("%s: RSS: %zdMb\n", SanitizerToolName, current_rss_mb);
        prev_reported_rss = current_rss_mb;
      }
      // If stack depot has grown 10% since last time, print it too.
      StackDepotStats *stack_depot_stats = StackDepotGetStats();
      if (stack_depot_stats) {
        if (prev_reported_stack_depot_size * 11 / 10 <
            stack_depot_stats->allocated) {
          Printf("%s: StackDepot: %zd ids; %zdM allocated\n",
                 SanitizerToolName,
                 stack_depot_stats->n_uniq_ids,
                 stack_depot_stats->allocated >> 20);
          prev_reported_stack_depot_size = stack_depot_stats->allocated;
        }
      }
    }
    // Check RSS against the limit.
    if (hard_rss_limit_mb && hard_rss_limit_mb < current_rss_mb) {
      Report("%s: hard rss limit exhausted (%zdMb vs %zdMb)\n",
             SanitizerToolName, hard_rss_limit_mb, current_rss_mb);
      DumpProcessMap();
      Die();
    }
    if (soft_rss_limit_mb) {
      if (soft_rss_limit_mb < current_rss_mb && !reached_soft_rss_limit) {
        reached_soft_rss_limit = true;
        Report("%s: soft rss limit exhausted (%zdMb vs %zdMb)\n",
               SanitizerToolName, soft_rss_limit_mb, current_rss_mb);
        if (SoftRssLimitExceededCallback)
          SoftRssLimitExceededCallback(true);
      } else if (soft_rss_limit_mb >= current_rss_mb &&
                 reached_soft_rss_limit) {
        reached_soft_rss_limit = false;
        if (SoftRssLimitExceededCallback)
          SoftRssLimitExceededCallback(false);
      }
    }
    if (heap_profile &&
        current_rss_mb > rss_during_last_reported_profile * 1.1) {
      Printf("\n\nHEAP PROFILE at RSS %zdMb\n", current_rss_mb);
      __sanitizer_print_memory_profile(90, 20);
      rss_during_last_reported_profile = current_rss_mb;
    }
  }
}
#endif

void WriteToSyslog(const char *msg) {
  InternalScopedString msg_copy(kErrorMessageBufferSize);
  msg_copy.append("%s", msg);
  char *p = msg_copy.data();
  char *q;

  // Print one line at a time.
  // syslog, at least on Android, has an implicit message length limit.
  while ((q = internal_strchr(p, '\n'))) {
    *q = '\0';
    WriteOneLineToSyslog(p);
    p = q + 1;
  }
  // Print remaining characters, if there are any.
  // Note that this will add an extra newline at the end.
  // FIXME: buffer extra output. This would need a thread-local buffer, which
  // on Android requires plugging into the tools (ex. ASan's) Thread class.
  if (*p)
    WriteOneLineToSyslog(p);
}

void MaybeStartBackgroudThread() {
#if (SANITIZER_LINUX || SANITIZER_NETBSD) && \
    !SANITIZER_GO  // Need to implement/test on other platforms.
  // Start the background thread if one of the rss limits is given.
  if (!common_flags()->hard_rss_limit_mb &&
      !common_flags()->soft_rss_limit_mb &&
      !common_flags()->heap_profile) return;
  if (!&real_pthread_create) return;  // Can't spawn the thread anyway.
  internal_start_thread(BackgroundThread, nullptr);
#endif
}

static void (*sandboxing_callback)();
void SetSandboxingCallback(void (*f)()) {
  sandboxing_callback = f;
}

}  // namespace __sanitizer

SANITIZER_INTERFACE_WEAK_DEF(void, __sanitizer_sandbox_on_notify,
                             __sanitizer_sandbox_arguments *args) {
  __sanitizer::PlatformPrepareForSandboxing(args);
  if (__sanitizer::sandboxing_callback)
    __sanitizer::sandboxing_callback();
}