Adding upstream version 86.0.1.upstream/86.0.1upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

6 files changed, 845 insertions, 0 deletions

diff --git a/tools/jprof/stub/Makefile.in b/tools/jprof/stub/Makefile.in
new file mode 100644
index 0000000000..8e6b6b8f8d
--- /dev/null
+++ b/tools/jprof/stub/Makefile.in
@@ -0,0 +1,8 @@
+#! gmake
+#
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+# override optimization
+MOZ_OPTIMIZE_FLAGS = -fno-omit-frame-pointer
diff --git a/tools/jprof/stub/config.h b/tools/jprof/stub/config.h
new file mode 100644
index 0000000000..6e5789452a
--- /dev/null
+++ b/tools/jprof/stub/config.h
@@ -0,0 +1,18 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef config_h___
+#define config_h___
+
+#define MAX_STACK_CRAWL 500
+#define M_LOGFILE "jprof-log"
+#define M_MAPFILE "jprof-map"
+
+#if defined(linux) || defined(NTO)
+#  define USE_BFD
+#  undef NEED_WRAPPERS
+
+#endif /* linux */
+
+#endif /* config_h___ */
diff --git a/tools/jprof/stub/jprof.h b/tools/jprof/stub/jprof.h
new file mode 100644
index 0000000000..c118760750
--- /dev/null
+++ b/tools/jprof/stub/jprof.h
@@ -0,0 +1,17 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef jprof_h___
+#define jprof_h___
+#include "nscore.h"
+
+#ifdef _IMPL_JPPROF_API
+#  define JPROF_API(type) NS_EXPORT_(type)
+#else
+#  define JPROF_API(type) NS_IMPORT_(type)
+#endif
+
+JPROF_API(void) setupProfilingStuff(void);
+
+#endif /* jprof_h___ */
diff --git a/tools/jprof/stub/libmalloc.cpp b/tools/jprof/stub/libmalloc.cpp
new file mode 100644
index 0000000000..3003543a93
--- /dev/null
+++ b/tools/jprof/stub/libmalloc.cpp
@@ -0,0 +1,740 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+// vim:cindent:sw=4:et:ts=8:
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+// The linux glibc hides part of sigaction if _POSIX_SOURCE is defined
+#if defined(linux)
+#  undef _POSIX_SOURCE
+#  undef _SVID_SOURCE
+#  ifndef _GNU_SOURCE
+#    define _GNU_SOURCE
+#  endif
+#endif
+
+#include <errno.h>
+#if defined(linux)
+#  include <linux/rtc.h>
+#  include <pthread.h>
+#endif
+#include <unistd.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <signal.h>
+#include <sys/time.h>
+#include <sys/types.h>
+#include <sys/ioctl.h>
+#include <sys/stat.h>
+#include <sys/syscall.h>
+#include <ucontext.h>
+#include <execinfo.h>
+
+#include "libmalloc.h"
+#include "jprof.h"
+#include <string.h>
+#include <errno.h>
+#include <dlfcn.h>
+
+#ifdef NTO
+#  include <sys/link.h>
+extern r_debug _r_debug;
+#else
+#  include <link.h>
+#endif
+
+#define USE_GLIBC_BACKTRACE 1
+// To debug, use #define JPROF_STATIC
+#define JPROF_STATIC static
+
+static int gLogFD = -1;
+static pthread_t main_thread;
+
+static bool gIsChild = false;
+static int gFilenamePID;
+
+static void startSignalCounter(unsigned long millisec);
+static int enableRTCSignals(bool enable);
+
+//----------------------------------------------------------------------
+// replace use of atexit()
+
+static void DumpAddressMap();
+
+struct JprofShutdown {
+  JprofShutdown() {}
+  ~JprofShutdown() { DumpAddressMap(); }
+};
+
+static void RegisterJprofShutdown() {
+  // This instanciates the dummy class above, and will trigger the class
+  // destructor when libxul is unloaded. This is equivalent to atexit(),
+  // but gracefully handles dlclose().
+  static JprofShutdown t;
+}
+
+#if defined(i386) || defined(_i386) || defined(__x86_64__)
+JPROF_STATIC void CrawlStack(malloc_log_entry* me, void* stack_top,
+                             void* top_instr_ptr) {
+#  if USE_GLIBC_BACKTRACE
+  // This probably works on more than x86!  But we need a way to get the
+  // top instruction pointer, which is kindof arch-specific
+  void* array[500];
+  int cnt, i;
+  u_long numpcs = 0;
+
+  // This is from glibc.  A more generic version might use
+  // libunwind and/or CaptureStackBackTrace() on Windows
+  cnt = backtrace(&array[0], sizeof(array) / sizeof(array[0]));
+
+  // StackHook->JprofLog->CrawlStack
+  // Then we have sigaction, which replaced top_instr_ptr
+  array[3] = top_instr_ptr;
+  for (i = 3; i < cnt; i++) {
+    me->pcs[numpcs++] = (char*)array[i];
+  }
+  me->numpcs = numpcs;
+
+#  else
+  // original code - this breaks on many platforms
+  void** bp;
+#    if defined(__i386)
+  __asm__("movl %%ebp, %0" : "=g"(bp));
+#    elif defined(__x86_64__)
+  __asm__("movq %%rbp, %0" : "=g"(bp));
+#    else
+  // It would be nice if this worked uniformly, but at least on i386 and
+  // x86_64, it stopped working with gcc 4.1, because it points to the
+  // end of the saved registers instead of the start.
+  bp = __builtin_frame_address(0);
+#    endif
+  u_long numpcs = 0;
+  bool tracing = false;
+
+  me->pcs[numpcs++] = (char*)top_instr_ptr;
+
+  while (numpcs < MAX_STACK_CRAWL) {
+    void** nextbp = (void**)*bp++;
+    void* pc = *bp;
+    if (nextbp < bp) {
+      break;
+    }
+    if (tracing) {
+      // Skip the signal handling.
+      me->pcs[numpcs++] = (char*)pc;
+    } else if (pc == top_instr_ptr) {
+      tracing = true;
+    }
+    bp = nextbp;
+  }
+  me->numpcs = numpcs;
+#  endif
+}
+#endif
+
+//----------------------------------------------------------------------
+
+static int rtcHz;
+static int rtcFD = -1;
+static bool circular = false;
+
+#if defined(linux) || defined(NTO)
+static void DumpAddressMap() {
+  // Turn off the timer so we don't get interrupts during shutdown
+#  if defined(linux)
+  if (rtcHz) {
+    enableRTCSignals(false);
+  } else
+#  endif
+  {
+    startSignalCounter(0);
+  }
+
+  char filename[2048];
+  if (gIsChild)
+    snprintf(filename, sizeof(filename), "%s-%d", M_MAPFILE, gFilenamePID);
+  else
+    snprintf(filename, sizeof(filename), "%s", M_MAPFILE);
+
+  int mfd = open(filename, O_CREAT | O_WRONLY | O_TRUNC, 0666);
+  if (mfd >= 0) {
+    malloc_map_entry mme;
+    link_map* map = _r_debug.r_map;
+    while (nullptr != map) {
+      if (map->l_name && *map->l_name) {
+        mme.nameLen = strlen(map->l_name);
+        mme.address = map->l_addr;
+        write(mfd, &mme, sizeof(mme));
+        write(mfd, map->l_name, mme.nameLen);
+#  if 0
+	write(1, map->l_name, mme.nameLen);
+	write(1, "\n", 1);
+#  endif
+      }
+      map = map->l_next;
+    }
+    close(mfd);
+  }
+}
+#endif
+
+static bool was_paused = true;
+
+JPROF_STATIC void JprofBufferDump();
+JPROF_STATIC void JprofBufferClear();
+
+static void ClearProfilingHook(int signum) {
+  if (circular) {
+    JprofBufferClear();
+    puts("Jprof: cleared circular buffer.");
+  }
+}
+
+static void EndProfilingHook(int signum) {
+  if (circular) JprofBufferDump();
+
+  DumpAddressMap();
+  was_paused = true;
+  puts("Jprof: profiling paused.");
+}
+
+//----------------------------------------------------------------------
+// proper usage would be a template, including the function to find the
+// size of an entry, or include a size header explicitly to each entry.
+#if defined(linux)
+#  define DUMB_LOCK() pthread_mutex_lock(&mutex);
+#  define DUMB_UNLOCK() pthread_mutex_unlock(&mutex);
+#else
+#  define DUMB_LOCK() FIXME()
+#  define DUMB_UNLOCK() FIXME()
+#endif
+
+class DumbCircularBuffer {
+ public:
+  DumbCircularBuffer(size_t init_buffer_size) {
+    used = 0;
+    buffer_size = init_buffer_size;
+    buffer = (unsigned char*)malloc(buffer_size);
+    head = tail = buffer;
+
+#if defined(linux)
+    pthread_mutexattr_t mAttr;
+    pthread_mutexattr_settype(&mAttr, PTHREAD_MUTEX_RECURSIVE_NP);
+    pthread_mutex_init(&mutex, &mAttr);
+    pthread_mutexattr_destroy(&mAttr);
+#endif
+  }
+  ~DumbCircularBuffer() {
+    free(buffer);
+#if defined(linux)
+    pthread_mutex_destroy(&mutex);
+#endif
+  }
+
+  void clear() {
+    DUMB_LOCK();
+    head = tail;
+    used = 0;
+    DUMB_UNLOCK();
+  }
+
+  bool empty() { return head == tail; }
+
+  size_t space_available() {
+    size_t result;
+    DUMB_LOCK();
+    if (tail > head)
+      result = buffer_size - (tail - head) - 1;
+    else
+      result = head - tail - 1;
+    DUMB_UNLOCK();
+    return result;
+  }
+
+  void drop(size_t size) {
+    // assumes correctness!
+    DUMB_LOCK();
+    head += size;
+    if (head >= &buffer[buffer_size]) head -= buffer_size;
+    used--;
+    DUMB_UNLOCK();
+  }
+
+  bool insert(void* data, size_t size) {
+    // can fail if not enough space in the entire buffer
+    DUMB_LOCK();
+    if (space_available() < size) return false;
+
+    size_t max_without_wrap = &buffer[buffer_size] - tail;
+    size_t initial = size > max_without_wrap ? max_without_wrap : size;
+#if DEBUG_CIRCULAR
+    fprintf(stderr, "insert(%d): max_without_wrap %d, size %d, initial %d\n",
+            used, max_without_wrap, size, initial);
+#endif
+    memcpy(tail, data, initial);
+    tail += initial;
+    data = ((char*)data) + initial;
+    size -= initial;
+    if (size != 0) {
+#if DEBUG_CIRCULAR
+      fprintf(stderr, "wrapping by %d bytes\n", size);
+#endif
+      memcpy(buffer, data, size);
+      tail = &(((unsigned char*)buffer)[size]);
+    }
+
+    used++;
+    DUMB_UNLOCK();
+
+    return true;
+  }
+
+  // for external access to the buffer (saving)
+  void lock() { DUMB_LOCK(); }
+
+  void unlock() { DUMB_UNLOCK(); }
+
+  // XXX These really shouldn't be public...
+  unsigned char* head;
+  unsigned char* tail;
+  unsigned int used;
+  unsigned char* buffer;
+  size_t buffer_size;
+
+ private:
+  pthread_mutex_t mutex;
+};
+
+class DumbCircularBuffer* JprofBuffer;
+
+JPROF_STATIC void JprofBufferInit(size_t size) {
+  JprofBuffer = new DumbCircularBuffer(size);
+}
+
+JPROF_STATIC void JprofBufferClear() {
+  fprintf(stderr, "Told to clear JPROF circular buffer\n");
+  JprofBuffer->clear();
+}
+
+JPROF_STATIC size_t JprofEntrySizeof(malloc_log_entry* me) {
+  return offsetof(malloc_log_entry, pcs) + me->numpcs * sizeof(char*);
+}
+
+JPROF_STATIC void JprofBufferAppend(malloc_log_entry* me) {
+  size_t size = JprofEntrySizeof(me);
+
+  do {
+    while (JprofBuffer->space_available() < size && JprofBuffer->used > 0) {
+#if DEBUG_CIRCULAR
+      fprintf(
+          stderr,
+          "dropping entry: %d in use, %d free, need %d, size_to_free = %d\n",
+          JprofBuffer->used, JprofBuffer->space_available(), size,
+          JprofEntrySizeof((malloc_log_entry*)JprofBuffer->head));
+#endif
+      JprofBuffer->drop(JprofEntrySizeof((malloc_log_entry*)JprofBuffer->head));
+    }
+    if (JprofBuffer->space_available() < size) return;
+
+  } while (!JprofBuffer->insert(me, size));
+}
+
+JPROF_STATIC void JprofBufferDump() {
+  JprofBuffer->lock();
+#if DEBUG_CIRCULAR
+  fprintf(
+      stderr, "dumping JP_CIRCULAR buffer, %d of %d bytes\n",
+      JprofBuffer->tail > JprofBuffer->head
+          ? JprofBuffer->tail - JprofBuffer->head
+          : JprofBuffer->buffer_size + JprofBuffer->tail - JprofBuffer->head,
+      JprofBuffer->buffer_size);
+#endif
+  if (JprofBuffer->tail >= JprofBuffer->head) {
+    write(gLogFD, JprofBuffer->head, JprofBuffer->tail - JprofBuffer->head);
+  } else {
+    write(gLogFD, JprofBuffer->head,
+          &(JprofBuffer->buffer[JprofBuffer->buffer_size]) - JprofBuffer->head);
+    write(gLogFD, JprofBuffer->buffer, JprofBuffer->tail - JprofBuffer->buffer);
+  }
+  JprofBuffer->clear();
+  JprofBuffer->unlock();
+}
+
+//----------------------------------------------------------------------
+
+JPROF_STATIC void JprofLog(u_long aTime, void* stack_top, void* top_instr_ptr) {
+  // Static is simply to make debugging tolerable
+  static malloc_log_entry me;
+
+  me.delTime = aTime;
+  me.thread = syscall(SYS_gettid);  // gettid();
+  if (was_paused) {
+    me.flags = JP_FIRST_AFTER_PAUSE;
+    was_paused = 0;
+  } else {
+    me.flags = 0;
+  }
+
+  CrawlStack(&me, stack_top, top_instr_ptr);
+
+#ifndef NTO
+  if (circular) {
+    JprofBufferAppend(&me);
+  } else {
+    write(gLogFD, &me, JprofEntrySizeof(&me));
+  }
+#else
+  printf("Neutrino is missing the pcs member of malloc_log_entry!! \n");
+#endif
+}
+
+static int realTime;
+
+/* Lets interrupt at 10 Hz.  This is so my log files don't get too large.
+ * This can be changed to a faster value latter.  This timer is not
+ * programmed to reset, even though it is capable of doing so.  This is
+ * to keep from getting interrupts from inside of the handler.
+ */
+static void startSignalCounter(unsigned long millisec) {
+  struct itimerval tvalue;
+
+  tvalue.it_interval.tv_sec = 0;
+  tvalue.it_interval.tv_usec = 0;
+  tvalue.it_value.tv_sec = millisec / 1000;
+  tvalue.it_value.tv_usec = (millisec % 1000) * 1000;
+
+  if (realTime) {
+    setitimer(ITIMER_REAL, &tvalue, nullptr);
+  } else {
+    setitimer(ITIMER_PROF, &tvalue, nullptr);
+  }
+}
+
+static long timerMilliSec = 50;
+
+#if defined(linux)
+static int setupRTCSignals(int hz, struct sigaction* sap) {
+  /* global */ rtcFD = open("/dev/rtc", O_RDONLY);
+  if (rtcFD < 0) {
+    perror("JPROF_RTC setup: open(\"/dev/rtc\", O_RDONLY)");
+    return 0;
+  }
+
+  if (sigaction(SIGIO, sap, nullptr) == -1) {
+    perror("JPROF_RTC setup: sigaction(SIGIO)");
+    return 0;
+  }
+
+  if (ioctl(rtcFD, RTC_IRQP_SET, hz) == -1) {
+    perror("JPROF_RTC setup: ioctl(/dev/rtc, RTC_IRQP_SET, $JPROF_RTC_HZ)");
+    return 0;
+  }
+
+  if (ioctl(rtcFD, RTC_PIE_ON, 0) == -1) {
+    perror("JPROF_RTC setup: ioctl(/dev/rtc, RTC_PIE_ON)");
+    return 0;
+  }
+
+  if (fcntl(rtcFD, F_SETSIG, 0) == -1) {
+    perror("JPROF_RTC setup: fcntl(/dev/rtc, F_SETSIG, 0)");
+    return 0;
+  }
+
+  if (fcntl(rtcFD, F_SETOWN, getpid()) == -1) {
+    perror("JPROF_RTC setup: fcntl(/dev/rtc, F_SETOWN, getpid())");
+    return 0;
+  }
+
+  return 1;
+}
+
+static int enableRTCSignals(bool enable) {
+  static bool enabled = false;
+  if (enabled == enable) {
+    return 0;
+  }
+  enabled = enable;
+
+  int flags = fcntl(rtcFD, F_GETFL);
+  if (flags < 0) {
+    perror("JPROF_RTC setup: fcntl(/dev/rtc, F_GETFL)");
+    return 0;
+  }
+
+  if (enable) {
+    flags |= FASYNC;
+  } else {
+    flags &= ~FASYNC;
+  }
+
+  if (fcntl(rtcFD, F_SETFL, flags) == -1) {
+    if (enable) {
+      perror("JPROF_RTC setup: fcntl(/dev/rtc, F_SETFL, flags | FASYNC)");
+    } else {
+      perror("JPROF_RTC setup: fcntl(/dev/rtc, F_SETFL, flags & ~FASYNC)");
+    }
+    return 0;
+  }
+
+  return 1;
+}
+#endif
+
+JPROF_STATIC void StackHook(int signum, siginfo_t* info, void* ucontext) {
+  static struct timeval tFirst;
+  static int first = 1;
+  size_t millisec = 0;
+
+#if defined(linux)
+  if (rtcHz && pthread_self() != main_thread) {
+    // Only collect stack data on the main thread, for now.
+    return;
+  }
+#endif
+
+  if (first && !(first = 0)) {
+    puts("Jprof: received first signal");
+#if defined(linux)
+    if (rtcHz) {
+      enableRTCSignals(true);
+    } else
+#endif
+    {
+      gettimeofday(&tFirst, 0);
+      millisec = 0;
+    }
+  } else {
+#if defined(linux)
+    if (rtcHz) {
+      enableRTCSignals(true);
+    } else
+#endif
+    {
+      struct timeval tNow;
+      gettimeofday(&tNow, 0);
+      double usec = 1e6 * (tNow.tv_sec - tFirst.tv_sec);
+      usec += (tNow.tv_usec - tFirst.tv_usec);
+      millisec = static_cast<size_t>(usec * 1e-3);
+    }
+  }
+
+  gregset_t& gregs = ((ucontext_t*)ucontext)->uc_mcontext.gregs;
+#ifdef __x86_64__
+  JprofLog(millisec, (void*)gregs[REG_RSP], (void*)gregs[REG_RIP]);
+#else
+  JprofLog(millisec, (void*)gregs[REG_ESP], (void*)gregs[REG_EIP]);
+#endif
+
+  if (!rtcHz) startSignalCounter(timerMilliSec);
+}
+
+NS_EXPORT_(void) setupProfilingStuff(void) {
+  static int gFirstTime = 1;
+  char filename[2048];  // XXX fix
+
+  if (gFirstTime && !(gFirstTime = 0)) {
+    int startTimer = 1;
+    int doNotStart = 1;
+    int firstDelay = 0;
+    int append = O_TRUNC;
+    char* tst = getenv("JPROF_FLAGS");
+
+    /* Options from JPROF_FLAGS environment variable:
+     *   JP_DEFER  -> Wait for a SIGPROF (or SIGALRM, if JP_REALTIME
+     *               is set) from userland before starting
+     *               to generate them internally
+     *   JP_START  -> Install the signal handler
+     *   JP_PERIOD -> Time between profiler ticks
+     *   JP_FIRST  -> Extra delay before starting
+     *   JP_REALTIME -> Take stack traces in intervals of real time
+     *               rather than time used by the process (and the
+     *               system for the process).  This is useful for
+     *               finding time spent by the X server.
+     *   JP_APPEND -> Append to jprof-log rather than overwriting it.
+     *               This is somewhat risky since it depends on the
+     *               address map staying constant across multiple runs.
+     *   JP_FILENAME -> base filename to use when saving logs.  Note that
+     *               this does not affect the mapfile.
+     *   JP_CIRCULAR -> use a circular buffer of size N, write/clear on SIGUSR1
+     *
+     * JPROF_ISCHILD is set if this is not the first process.
+     */
+
+    circular = false;
+
+    if (tst) {
+      if (strstr(tst, "JP_DEFER")) {
+        doNotStart = 0;
+        startTimer = 0;
+      }
+      if (strstr(tst, "JP_START")) doNotStart = 0;
+      if (strstr(tst, "JP_REALTIME")) realTime = 1;
+      if (strstr(tst, "JP_APPEND")) append = O_APPEND;
+
+      char* delay = strstr(tst, "JP_PERIOD=");
+      if (delay) {
+        double tmp = strtod(delay + strlen("JP_PERIOD="), nullptr);
+        if (tmp >= 1e-3) {
+          timerMilliSec = static_cast<unsigned long>(1000 * tmp);
+        } else {
+          fprintf(stderr, "JP_PERIOD of %g less than 0.001 (1ms), using 1ms\n",
+                  tmp);
+          timerMilliSec = 1;
+        }
+      }
+
+      char* circular_op = strstr(tst, "JP_CIRCULAR=");
+      if (circular_op) {
+        size_t size = atol(circular_op + strlen("JP_CIRCULAR="));
+        if (size < 1000) {
+          fprintf(stderr, "JP_CIRCULAR of %lu less than 1000, using 10000\n",
+                  (unsigned long)size);
+          size = 10000;
+        }
+        JprofBufferInit(size);
+        fprintf(stderr, "JP_CIRCULAR buffer of %lu bytes\n",
+                (unsigned long)size);
+        circular = true;
+      }
+
+      char* first = strstr(tst, "JP_FIRST=");
+      if (first) {
+        firstDelay = atol(first + strlen("JP_FIRST="));
+      }
+
+      char* rtc = strstr(tst, "JP_RTC_HZ=");
+      if (rtc) {
+#if defined(linux)
+        rtcHz = atol(rtc + strlen("JP_RTC_HZ="));
+        timerMilliSec = 0; /* This makes JP_FIRST work right. */
+        realTime = 1;      /* It's the _R_TC and all.  ;) */
+
+#  define IS_POWER_OF_TWO(x) (((x) & ((x)-1)) == 0)
+
+        if (!IS_POWER_OF_TWO(rtcHz) || rtcHz < 2) {
+          fprintf(stderr,
+                  "JP_RTC_HZ must be power of two and >= 2, "
+                  "but %d was provided; using default of 2048\n",
+                  rtcHz);
+          rtcHz = 2048;
+        }
+#else
+        fputs(
+            "JP_RTC_HZ found, but RTC profiling only supported on "
+            "Linux!\n",
+            stderr);
+
+#endif
+      }
+      const char* f = strstr(tst, "JP_FILENAME=");
+      if (f)
+        f = f + strlen("JP_FILENAME=");
+      else
+        f = M_LOGFILE;
+
+      char* is_child = getenv("JPROF_ISCHILD");
+      if (!is_child) setenv("JPROF_ISCHILD", "", 0);
+      gIsChild = !!is_child;
+
+      gFilenamePID = syscall(SYS_gettid);  // gettid();
+      if (is_child)
+        snprintf(filename, sizeof(filename), "%s-%d", f, gFilenamePID);
+      else
+        snprintf(filename, sizeof(filename), "%s", f);
+
+      // XXX FIX! inherit current capture state!
+    }
+
+    if (!doNotStart) {
+      if (gLogFD < 0) {
+        gLogFD = open(filename, O_CREAT | O_WRONLY | append, 0666);
+        if (gLogFD < 0) {
+          fprintf(stderr, "Unable to create " M_LOGFILE);
+          perror(":");
+        } else {
+          struct sigaction action;
+          sigset_t mset;
+
+          // Dump out the address map when we terminate
+          RegisterJprofShutdown();
+
+          main_thread = pthread_self();
+          // fprintf(stderr,"jprof: main_thread = %u\n",
+          //        (unsigned int)main_thread);
+
+          // FIX!  probably should block these against each other
+          // Very unlikely.
+          sigemptyset(&mset);
+          action.sa_handler = nullptr;
+          action.sa_sigaction = StackHook;
+          action.sa_mask = mset;
+          action.sa_flags = SA_RESTART | SA_SIGINFO;
+#if defined(linux)
+          if (rtcHz) {
+            if (!setupRTCSignals(rtcHz, &action)) {
+              fputs(
+                  "jprof: Error initializing RTC, NOT "
+                  "profiling\n",
+                  stderr);
+              return;
+            }
+          }
+
+          if (!rtcHz || firstDelay != 0)
+#endif
+          {
+            if (realTime) {
+              sigaction(SIGALRM, &action, nullptr);
+            }
+          }
+          // enable PROF in all cases to simplify JP_DEFER/pause/restart
+          sigaction(SIGPROF, &action, nullptr);
+
+          // make it so a SIGUSR1 will stop the profiling
+          // Note:  It currently does not close the logfile.
+          // This could be configurable (so that it could
+          // later be reopened).
+
+          struct sigaction stop_action;
+          stop_action.sa_handler = EndProfilingHook;
+          stop_action.sa_mask = mset;
+          stop_action.sa_flags = SA_RESTART;
+          sigaction(SIGUSR1, &stop_action, nullptr);
+
+          // make it so a SIGUSR2 will clear the circular buffer
+
+          stop_action.sa_handler = ClearProfilingHook;
+          stop_action.sa_mask = mset;
+          stop_action.sa_flags = SA_RESTART;
+          sigaction(SIGUSR2, &stop_action, nullptr);
+
+          printf(
+              "Jprof: Initialized signal handler and set "
+              "timer for %lu %s, %d s "
+              "initial delay\n",
+              rtcHz ? rtcHz : timerMilliSec, rtcHz ? "Hz" : "ms", firstDelay);
+
+          if (startTimer) {
+#if defined(linux)
+            /* If we have an initial delay we can just use
+               startSignalCounter to set up a timer to fire the
+               first stackHook after that delay.  When that happens
+               we'll go and switch to RTC profiling. */
+            if (rtcHz && firstDelay == 0) {
+              puts("Jprof: enabled RTC signals");
+              enableRTCSignals(true);
+            } else
+#endif
+            {
+              puts("Jprof: started timer");
+              startSignalCounter(firstDelay * 1000 + timerMilliSec);
+            }
+          }
+        }
+      }
+    }
+  } else {
+    printf("setupProfilingStuff() called multiple times\n");
+  }
+}
diff --git a/tools/jprof/stub/libmalloc.h b/tools/jprof/stub/libmalloc.h
new file mode 100644
index 0000000000..a78b35ade8
--- /dev/null
+++ b/tools/jprof/stub/libmalloc.h
@@ -0,0 +1,45 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef libmalloc_h___
+#define libmalloc_h___
+
+#include <sys/types.h>
+#include <malloc.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include "config.h"
+
+typedef unsigned long u_long;
+
+// For me->flags
+#define JP_FIRST_AFTER_PAUSE 1
+
+// Format of a jprof log entry. This is what's written out to the
+// "jprof-log" file.
+// It's called malloc_log_entry because the history of jprof is that
+// it's a modified version of tracemalloc.
+struct malloc_log_entry {
+  u_long delTime;
+  u_long numpcs;
+  unsigned int flags;
+  int thread;
+  char* pcs[MAX_STACK_CRAWL];
+};
+
+// Format of a malloc map entry; after this struct is nameLen+1 bytes of
+// name data.
+struct malloc_map_entry {
+  u_long nameLen;
+  u_long address;  // base address
+};
+
+#ifdef __cplusplus
+} /* end of extern "C" */
+#endif
+
+#endif /* libmalloc_h___ */
diff --git a/tools/jprof/stub/moz.build b/tools/jprof/stub/moz.build
new file mode 100644
index 0000000000..692c6ea37f
--- /dev/null
+++ b/tools/jprof/stub/moz.build
@@ -0,0 +1,17 @@
+# -*- Mode: python; indent-tabs-mode: nil; tab-width: 40 -*-
+# vim: set filetype=python:
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+EXPORTS += [
+    "jprof.h",
+]
+
+SOURCES += [
+    "libmalloc.cpp",
+]
+
+SharedLibrary("jprof")
+
+DEFINES["_IMPL_JPROF_API"] = True