final push to stable (really?) (#939)

* sync (#886)

* Create FUNDING.yml

* Update FUNDING.yml

* moved custom_mutator examples

* unicorn speedtest makefile cleanup

* fixed example location

* fix qdbi

* update util readme

* Frida persistent (#880)

* Added x64 support for persistent mode (function call only), in-memory teest cases and complog

* Review changes, fix NeverZero and code to parse the .text section of the main executable. Excluded ranges TBC

* Various minor fixes and finished support for AFL_INST_LIBS

* Review changes

Co-authored-by: Your Name <you@example.com>

* nits

* fix frida mode

* Integer overflow/underflow fixes in libdislocator (#889)

* libdislocator: fixing integer overflow in 'max_mem' variable and setting 'max_mem' type to 'size_t'

* libdislocator: fixing potential integer underflow in 'total_mem' variable due to its different values in different threads

* Bumped warnings up to the max and fixed remaining issues (#890)

Co-authored-by: Your Name <you@example.com>

* nits

* frida mode - support non-pie

* nits

* nit

* update grammar mutator

* Fixes for aarch64, OSX and other minor issues (#891)

Co-authored-by: Your Name <you@example.com>

* nits

* nits

* fix PCGUARD, build aflpp_driver with fPIC

* Added representative fuzzbench test and test for libxml (#893)

* Added representative fuzzbench test and test for libxml

* Added support for building FRIDA from source with FRIDA_SOURCE=1

Co-authored-by: Your Name <you@example.com>

* nits

* update changelog

* typos

* fixed potential double free in custom trim (#881)

* error handling, freeing mem

* frida: complog -> cmplog

* fix statsd writing

* let aflpp_qemu_driver_hook.so build fail gracefully

* fix stdin trimming

* Support for AFL_ENTRYPOINT (#898)

Co-authored-by: Your Name <you@example.com>

* remove the input file .cur_input at the end of the fuzzing, if AFL_TMPDIR is used

* reverse push (#901)

* Create FUNDING.yml

* Update FUNDING.yml

* disable QEMU static pie

Co-authored-by: Andrea Fioraldi <andreafioraldi@gmail.com>

* clarify that no modifications are required.

* add new test for frida_mode (please review)

* typos

* fix persistent mode (64-bit)

* set ARCH for linux intel 32-bit for frida-gum-devkit

* prepare for 32-bit support (later)

* not on qemu 3 anymore

* unicorn mips fixes

* instrumentation further move to C++11 (#900)

* unicorn fixes

* more unicorn fixes

* Fix memory errors when trim causes testcase growth (#881) (#903)

* Revert "fixed potential double free in custom trim (#881)"

This reverts commit e9d2f72382cab75832721d859c3e731da071435d.

* Revert "fix custom trim for increasing data"

This reverts commit 86a8ef168dda766d2f25f15c15c4d3ecf21d0667.

* Fix memory errors when trim causes testcase growth

Modify trim_case_custom to avoid writing into in_buf because
some custom mutators can cause the testcase to grow rather than
shrink.

Instead of modifying in_buf directly, we write the update out
to the disk when trimming is complete, and then the caller is
responsible for refreshing the in-memory buffer from the file.

This is still a bit sketchy because it does need to modify q->len in
order to notify the upper layers that something changed, and it could
end up telling upper layer code that the q->len is *bigger* than
the buffer (q->testcase_buf) that contains it, which is asking
for trouble down the line somewhere...

* Fix an unlikely situation

Put back some `unlikely()` calls that were in
the e9d2f72382cab75832721d859c3e731da071435d commit that was
reverted.

* typo

* Exit on time (#904)

* Variable AFL_EXIT_ON_TIME description has been added.
Variables AFL_EXIT_ON_TIME and afl_exit_on_time has been added.
afl->exit_on_time variable initialization has been added.
The asignment of a value to the afl->afl_env.afl_exit_on_time variable from
environment variables has been added.
Code to exit on timeout if new path not found has been added.

* Type of afl_exit_on_time variable has been changed.
Variable exit_on_time has been added to the afl_state_t structure.

* Command `export AFL_EXIT_WHEN_DONE=1` has been added.

* Millisecond to second conversion has been added.
Call get_cur_time() has been added.

* Revert to using the saved current time value.

* Useless check has been removed.

* fix new path to custom-mutators

* ensure crashes/README.txt exists

* fix

* Changes to bump FRIDA version and to clone FRIDA repo in to build directory rather than use a submodule as the FRIDA build scripts don't like it (#906)

Co-authored-by: Your Name <you@example.com>

* Fix numeric overflow in cmplog implementation (#907)

Co-authored-by: Your Name <you@example.com>

* testcase fixes for unicorn

* remove merge conflict artifacts

* fix afl-plot

* Changes to remove binaries from frida_mode (#913)

Co-authored-by: Your Name <you@example.com>

* Frida cmplog fail fast (#914)

* Changes to remove binaries from frida_mode

* Changes to make cmplog fail fast

Co-authored-by: Your Name <you@example.com>

* afl-plot: relative time

* arch linux and mac os support for afl-system-config

* typo

* code-format

* update documentation

* github workflow for qemu

* OSX-specific improvements (#912)

* Fix afl-cc to work correctly by default on OSX using xcode

- CLANG_ENV_VAR must be set for afl-as to work
- Use clang mode by default if no specific compiler selected

* Add OSX-specific documentation for configuring shared memory

* Fixes to memory operands for complog (#916)

Co-authored-by: Your Name <you@example.com>

* fix a few cur_time uses

* added bounds check to pivot_inputs (fixes #921)

* additional safety checks for restarts

* restrict afl-showmap in_file size

* fix seed crash disable

* add warning for afl-showmap partial read

* no core dumps

* AFL_PRINT_FILENAMES added

* more documentation for AFL_EXIT_ON_TIME

* Flushing for AFL_PRINT_FILENAMES

* FASAN Support (#918)

* FASAN Support

* Fix handling of Address Sanitizer DSO

* Changes to identification of Address Sanitizer DSO

Co-authored-by: Your Name <you@example.com>

* Support for x86 (#920)

Co-authored-by: Your Name <you@example.com>

* Update frida_mode readme (#925)

* libqasan: use syscalls for read and write

* update readme

* Minor integration tweaks (#926)

Co-authored-by: Your Name <you@example.com>

* merge

* fix afl-fuzz.c frida preload

* cleaned up AFL_PRINT_FILENAMES env

* Changes to have persistent mode exit at the end of the loop (#928)

Co-authored-by: Your Name <you@example.com>

* fix llvm-dict2file

* push to stable (#931) (#932)

* sync (#886)

* Create FUNDING.yml

* Update FUNDING.yml

* moved custom_mutator examples

* unicorn speedtest makefile cleanup

* fixed example location

* fix qdbi

* update util readme

* Frida persistent (#880)

* Added x64 support for persistent mode (function call only), in-memory teest cases and complog

* Review changes, fix NeverZero and code to parse the .text section of the main executable. Excluded ranges TBC

* Various minor fixes and finished support for AFL_INST_LIBS

* Review changes

Co-authored-by: Your Name <you@example.com>

* nits

* fix frida mode

* Integer overflow/underflow fixes in libdislocator (#889)

* libdislocator: fixing integer overflow in 'max_mem' variable and setting 'max_mem' type to 'size_t'

* libdislocator: fixing potential integer underflow in 'total_mem' variable due to its different values in different threads

* Bumped warnings up to the max and fixed remaining issues (#890)

Co-authored-by: Your Name <you@example.com>

* nits

* frida mode - support non-pie

* nits

* nit

* update grammar mutator

* Fixes for aarch64, OSX and other minor issues (#891)

Co-authored-by: Your Name <you@example.com>

* nits

* nits

* fix PCGUARD, build aflpp_driver with fPIC

* Added representative fuzzbench test and test for libxml (#893)

* Added representative fuzzbench test and test for libxml

* Added support for building FRIDA from source with FRIDA_SOURCE=1

Co-authored-by: Your Name <you@example.com>

* nits

* update changelog

* typos

* fixed potential double free in custom trim (#881)

* error handling, freeing mem

* frida: complog -> cmplog

* fix statsd writing

* let aflpp_qemu_driver_hook.so build fail gracefully

* fix stdin trimming

* Support for AFL_ENTRYPOINT (#898)

Co-authored-by: Your Name <you@example.com>

* remove the input file .cur_input at the end of the fuzzing, if AFL_TMPDIR is used

* reverse push (#901)

* Create FUNDING.yml

* Update FUNDING.yml

* disable QEMU static pie

Co-authored-by: Andrea Fioraldi <andreafioraldi@gmail.com>

* clarify that no modifications are required.

* add new test for frida_mode (please review)

* typos

* fix persistent mode (64-bit)

* set ARCH for linux intel 32-bit for frida-gum-devkit

* prepare for 32-bit support (later)

* not on qemu 3 anymore

* unicorn mips fixes

* instrumentation further move to C++11 (#900)

* unicorn fixes

* more unicorn fixes

* Fix memory errors when trim causes testcase growth (#881) (#903)

* Revert "fixed potential double free in custom trim (#881)"

This reverts commit e9d2f72382cab75832721d859c3e731da071435d.

* Revert "fix custom trim for increasing data"

This reverts commit 86a8ef168dda766d2f25f15c15c4d3ecf21d0667.

* Fix memory errors when trim causes testcase growth

Modify trim_case_custom to avoid writing into in_buf because
some custom mutators can cause the testcase to grow rather than
shrink.

Instead of modifying in_buf directly, we write the update out
to the disk when trimming is complete, and then the caller is
responsible for refreshing the in-memory buffer from the file.

This is still a bit sketchy because it does need to modify q->len in
order to notify the upper layers that something changed, and it could
end up telling upper layer code that the q->len is *bigger* than
the buffer (q->testcase_buf) that contains it, which is asking
for trouble down the line somewhere...

* Fix an unlikely situation

Put back some `unlikely()` calls that were in
the e9d2f72382cab75832721d859c3e731da071435d commit that was
reverted.

* typo

* Exit on time (#904)

* Variable AFL_EXIT_ON_TIME description has been added.
Variables AFL_EXIT_ON_TIME and afl_exit_on_time has been added.
afl->exit_on_time variable initialization has been added.
The asignment of a value to the afl->afl_env.afl_exit_on_time variable from
environment variables has been added.
Code to exit on timeout if new path not found has been added.

* Type of afl_exit_on_time variable has been changed.
Variable exit_on_time has been added to the afl_state_t structure.

* Command `export AFL_EXIT_WHEN_DONE=1` has been added.

* Millisecond to second conversion has been added.
Call get_cur_time() has been added.

* Revert to using the saved current time value.

* Useless check has been removed.

* fix new path to custom-mutators

* ensure crashes/README.txt exists

* fix

* Changes to bump FRIDA version and to clone FRIDA repo in to build directory rather than use a submodule as the FRIDA build scripts don't like it (#906)

Co-authored-by: Your Name <you@example.com>

* Fix numeric overflow in cmplog implementation (#907)

Co-authored-by: Your Name <you@example.com>

* testcase fixes for unicorn

* remove merge conflict artifacts

* fix afl-plot

* Changes to remove binaries from frida_mode (#913)

Co-authored-by: Your Name <you@example.com>

* Frida cmplog fail fast (#914)

* Changes to remove binaries from frida_mode

* Changes to make cmplog fail fast

Co-authored-by: Your Name <you@example.com>

* afl-plot: relative time

* arch linux and mac os support for afl-system-config

* typo

* code-format

* update documentation

* github workflow for qemu

* OSX-specific improvements (#912)

* Fix afl-cc to work correctly by default on OSX using xcode

- CLANG_ENV_VAR must be set for afl-as to work
- Use clang mode by default if no specific compiler selected

* Add OSX-specific documentation for configuring shared memory

* Fixes to memory operands for complog (#916)

Co-authored-by: Your Name <you@example.com>

* fix a few cur_time uses

* added bounds check to pivot_inputs (fixes #921)

* additional safety checks for restarts

* restrict afl-showmap in_file size

* fix seed crash disable

* add warning for afl-showmap partial read

* no core dumps

* AFL_PRINT_FILENAMES added

* more documentation for AFL_EXIT_ON_TIME

* Flushing for AFL_PRINT_FILENAMES

* FASAN Support (#918)

* FASAN Support

* Fix handling of Address Sanitizer DSO

* Changes to identification of Address Sanitizer DSO

Co-authored-by: Your Name <you@example.com>

* Support for x86 (#920)

Co-authored-by: Your Name <you@example.com>

* Update frida_mode readme (#925)

* libqasan: use syscalls for read and write

* update readme

* Minor integration tweaks (#926)

Co-authored-by: Your Name <you@example.com>

* merge

* fix afl-fuzz.c frida preload

* cleaned up AFL_PRINT_FILENAMES env

* Changes to have persistent mode exit at the end of the loop (#928)

Co-authored-by: Your Name <you@example.com>

* fix llvm-dict2file

Co-authored-by: Dominik Maier <domenukk@gmail.com>
Co-authored-by: WorksButNotTested <62701594+WorksButNotTested@users.noreply.github.com>
Co-authored-by: Your Name <you@example.com>
Co-authored-by: Dmitry Zheregelya <zheregelya.d@gmail.com>
Co-authored-by: hexcoder <hexcoder-@users.noreply.github.com>
Co-authored-by: hexcoder- <heiko@hexco.de>
Co-authored-by: Andrea Fioraldi <andreafioraldi@gmail.com>
Co-authored-by: David CARLIER <devnexen@gmail.com>
Co-authored-by: realmadsci <71108352+realmadsci@users.noreply.github.com>
Co-authored-by: Roman M. Iudichev <SecNotice@ya.ru>
Co-authored-by: Dustin Spicuzza <dustin@virtualroadside.com>

Co-authored-by: Dominik Maier <domenukk@gmail.com>
Co-authored-by: WorksButNotTested <62701594+WorksButNotTested@users.noreply.github.com>
Co-authored-by: Your Name <you@example.com>
Co-authored-by: Dmitry Zheregelya <zheregelya.d@gmail.com>
Co-authored-by: hexcoder <hexcoder-@users.noreply.github.com>
Co-authored-by: hexcoder- <heiko@hexco.de>
Co-authored-by: Andrea Fioraldi <andreafioraldi@gmail.com>
Co-authored-by: David CARLIER <devnexen@gmail.com>
Co-authored-by: realmadsci <71108352+realmadsci@users.noreply.github.com>
Co-authored-by: Roman M. Iudichev <SecNotice@ya.ru>
Co-authored-by: Dustin Spicuzza <dustin@virtualroadside.com>

* improve error msg

* Added documentation for wine LoadLibrary workaround (#933)

* Fix cmake target compilation command example (#934)

- Fix typo DCMAKE_C_COMPILERC -> DCMAKE_C_COMPILER.
- Add `cd build` after `mkdir build`.

* showmap passes queue items in alphabetical order

* added tmp files to gitignore

* lenient dict parsing, no map size enum for binary fuzzing

* added info about showmap queue directions

* update binary-only doc

* turn off map size detection if skip_bin_check is set

* Typo

* update docs

* update afl-system-config

* Set kill signal before using it in afl-showmap (#935)

* fix afl-cc help output

* add libafl to binary-only doc

* update docs

* less executions on variable paths

* AFL_SKIP_CRASHES is obsolete since 3.0

* add AFL_TRY_AFFINITY

* Typo

* Typo

* Typo/wording

* tweaks

* typos

* fix afl-whatsup help output

* fix afl-plot output

* fix for MacOS

* fix cmpcov doc for qemu

* fix tmpfile removal

* update dockerfile

* Frida (#940)

* Added re2 test

* Added libpcap test

* Fix validation of setting of ADDR_NO_RANDOMIZE

* Added support for printing original and instrumented code

Co-authored-by: Your Name <you@example.com>

* Support for AFL_FRIDA_PERSISTENT_RET (#941)

Co-authored-by: Your Name <you@example.com>

* Changes to add missing exclusion of ranges (#943)

Co-authored-by: Your Name <you@example.com>

* add --afl-noopt to afl-cc

* docs: fix link to README in QuickStartGuide (#946)

* Support writing Stalker stats (#945)

* Support writing Stalker stats

* Fixed string handling in print functions

Co-authored-by: Your Name <you@example.com>

* afl-cmin help fix, aflpp_driver - + @@ support

* fix for afl-showmap

Co-authored-by: Dominik Maier <domenukk@gmail.com>
Co-authored-by: WorksButNotTested <62701594+WorksButNotTested@users.noreply.github.com>
Co-authored-by: Your Name <you@example.com>
Co-authored-by: Dmitry Zheregelya <zheregelya.d@gmail.com>
Co-authored-by: hexcoder <hexcoder-@users.noreply.github.com>
Co-authored-by: hexcoder- <heiko@hexco.de>
Co-authored-by: Andrea Fioraldi <andreafioraldi@gmail.com>
Co-authored-by: David CARLIER <devnexen@gmail.com>
Co-authored-by: realmadsci <71108352+realmadsci@users.noreply.github.com>
Co-authored-by: Roman M. Iudichev <SecNotice@ya.ru>
Co-authored-by: Dustin Spicuzza <dustin@virtualroadside.com>
Co-authored-by: 0x4d5a-ctf <51098072+0x4d5a-ctf@users.noreply.github.com>
Co-authored-by: Tommy Chiang <oToToT@users.noreply.github.com>
Co-authored-by: buherator <buherator@silentsignal.hu>
Co-authored-by: Dag Heyman Kajevic <dag.heyman@gmail.com>

2 files changed, 176 insertions, 6 deletions

diff --git a/frida_mode/src/instrument/instrument.c b/frida_mode/src/instrument/instrument.c
index 67eadc3f..cd1ac0be 100644
--- a/frida_mode/src/instrument/instrument.c
+++ b/frida_mode/src/instrument/instrument.c
@@ -13,6 +13,7 @@
 #include "prefetch.h"
 #include "ranges.h"
 #include "stalker.h"
+#include "stats.h"
 #include "util.h"
 
 static gboolean               tracing = false;
@@ -47,7 +48,7 @@ __attribute__((hot)) static void on_basic_block(GumCpuContext *context,
                    "x, previous_pc: 0x%016" G_GINT64_MODIFIER "x\n",
                    current_pc, previous_pc);
 
-    IGNORED_RERURN(write(STDOUT_FILENO, buffer, len + 1));
+    IGNORED_RETURN(write(STDOUT_FILENO, buffer, len + 1));
 
   }
 
@@ -79,17 +80,52 @@ static void instr_basic_block(GumStalkerIterator *iterator,
 
   const cs_insn *instr;
   gboolean       begin = TRUE;
+  gboolean       excluded;
+
   while (gum_stalker_iterator_next(iterator, &instr)) {
 
     if (instr->address == entry_start) { entry_prologue(iterator, output); }
     if (instr->address == persistent_start) { persistent_prologue(output); }
-
-    if (begin) {
+    if (instr->address == persistent_ret) { persistent_epilogue(output); }
+
+    /*
+     * Until we reach AFL_ENTRYPOINT (assumed to be main if not specified) or
+     * AFL_FRIDA_PERSISTENT_ADDR (if specified), we don't mark our ranges
+     * excluded as we wish to remain inside stalker at all times so that we can
+     * instrument our entry point and persistent loop (if present). This allows
+     * the user to exclude ranges which would be traversed between main and the
+     * AFL_ENTRYPOINT, but which they don't want included in their coverage
+     * information when fuzzing.
+     *
+     * Since we have no means to discard the instrumented copies of blocks
+     * (setting the trust threshold simply causes a new copy to be made on each
+     * execution), we instead ensure that we honour the additional
+     * instrumentation requested (e.g. coverage, asan and complog) when a block
+     * is compiled no matter where we are during initialization. We will end up
+     * re-using these blocks if the code under test calls a block which is also
+     * used during initialization.
+     *
+     * Coverage data generated during initialization isn't a problem since the
+     * map is zeroed each time the target is forked or each time the persistent
+     * loop is run.
+     *
+     * Lastly, we don't enable pre-fetching back to the parent until we reach
+     * our AFL_ENTRYPOINT, since it is not until then that we start the
+     * fork-server and thus start executing in the child.
+     */
+    excluded = range_is_excluded(GSIZE_TO_POINTER(instr->address));
+
+    stats_collect(instr, begin);
+
+    if (unlikely(begin)) {
+
+      instrument_debug_start(instr->address, output);
 
       prefetch_write(GSIZE_TO_POINTER(instr->address));
-      if (!range_is_excluded(GSIZE_TO_POINTER(instr->address))) {
 
-        if (optimize) {
+      if (likely(!excluded)) {
+
+        if (likely(optimize)) {
 
           instrument_coverage_optimize(instr, output);
 
@@ -106,7 +142,9 @@ static void instr_basic_block(GumStalkerIterator *iterator,
 
     }
 
-    if (!range_is_excluded(GSIZE_TO_POINTER(instr->address))) {
+    instrument_debug_instruction(instr->address, instr->size);
+
+    if (likely(!excluded)) {
 
       asan_instrument(instr, iterator);
       cmplog_instrument(instr, iterator);
@@ -117,6 +155,8 @@ static void instr_basic_block(GumStalkerIterator *iterator,
 
   }
 
+  instrument_debug_end(output);
+
 }
 
 void instrument_init(void) {
@@ -144,6 +184,7 @@ void instrument_init(void) {
   transformer =
       gum_stalker_transformer_make_from_callback(instr_basic_block, NULL, NULL);
 
+  instrument_debug_init();
   asan_init();
   cmplog_init();
 
diff --git a/frida_mode/src/instrument/instrument_debug.c b/frida_mode/src/instrument/instrument_debug.c
new file mode 100644
index 00000000..be72ef89
--- /dev/null
+++ b/frida_mode/src/instrument/instrument_debug.c
@@ -0,0 +1,129 @@
+#include <fcntl.h>
+#include <stdarg.h>
+#include <stdio.h>
+#include <unistd.h>
+
+#include "frida-gum.h"
+
+#include "debug.h"
+
+#include "util.h"
+
+static int      debugging_fd = -1;
+static gpointer instrument_gen_start = NULL;
+
+static void instrument_debug(char *format, ...) {
+
+  va_list ap;
+  char    buffer[4096] = {0};
+  int     ret;
+  int len;
+
+  va_start(ap, format);
+  ret = vsnprintf(buffer, sizeof(buffer) - 1, format, ap);
+  va_end(ap);
+
+  if (ret < 0) { return; }
+
+  len = strnlen(buffer, sizeof(buffer));
+
+  IGNORED_RETURN(write(debugging_fd, buffer, len));
+
+}
+
+static void instrument_disasm(guint8 *code, guint size) {
+
+  csh      capstone;
+  cs_err   err;
+  cs_insn *insn;
+  size_t   count, i;
+
+  err = cs_open(GUM_DEFAULT_CS_ARCH,
+                GUM_DEFAULT_CS_MODE | GUM_DEFAULT_CS_ENDIAN, &capstone);
+  g_assert(err == CS_ERR_OK);
+
+  count = cs_disasm(capstone, code, size, GPOINTER_TO_SIZE(code), 0, &insn);
+  g_assert(insn != NULL);
+
+  for (i = 0; i != count; i++) {
+
+    instrument_debug("\t0x%" G_GINT64_MODIFIER "x\t%s %s\n", insn[i].address,
+                     insn[i].mnemonic, insn[i].op_str);
+
+  }
+
+  cs_free(insn, count);
+
+  cs_close(&capstone);
+
+}
+
+static gpointer instrument_cur(GumStalkerOutput *output) {
+
+#if defined(__i386__) || defined(__x86_64__)
+  return gum_x86_writer_cur(output->writer.x86);
+#elif defined(__aarch64__)
+  return gum_arm64_writer_cur(output->writer.arm64);
+#elif defined(__arm__)
+  return gum_arm_writer_cur(output->writer.arm);
+#else
+  #error "Unsupported architecture"
+#endif
+
+}
+
+void instrument_debug_init(void) {
+
+  char *filename = getenv("AFL_FRIDA_INST_DEBUG_FILE");
+  OKF("Instrumentation debugging - enabled [%c]", filename == NULL ? ' ' : 'X');
+
+  if (filename == NULL) { return; }
+
+  OKF("Instrumentation debugging - file [%s]", filename);
+
+  if (filename == NULL) { return; }
+
+  char *path = g_canonicalize_filename(filename, g_get_current_dir());
+
+  OKF("Instrumentation debugging - path [%s]", path);
+
+  debugging_fd = open(path, O_RDWR | O_CREAT | O_TRUNC,
+                      S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP);
+
+  if (debugging_fd < 0) { FATAL("Failed to open stats file '%s'", path); }
+
+  g_free(path);
+
+}
+
+void instrument_debug_start(uint64_t address, GumStalkerOutput *output) {
+
+  if (likely(debugging_fd < 0)) { return; }
+
+  instrument_gen_start = instrument_cur(output);
+
+  instrument_debug("\n\n***\n\nCreating block for 0x%" G_GINT64_MODIFIER "x:\n",
+                   address);
+
+}
+
+void instrument_debug_instruction(uint64_t address, uint16_t size) {
+
+  if (likely(debugging_fd < 0)) { return; }
+  uint8_t *start = (uint8_t *)GSIZE_TO_POINTER(address);
+  instrument_disasm(start, size);
+
+}
+
+void instrument_debug_end(GumStalkerOutput *output) {
+
+  if (likely(debugging_fd < 0)) { return; }
+  gpointer instrument_gen_end = instrument_cur(output);
+  uint16_t size = GPOINTER_TO_SIZE(instrument_gen_end) -
+                  GPOINTER_TO_SIZE(instrument_gen_start);
+
+  instrument_debug("\nGenerated block %p\n", instrument_gen_start);
+  instrument_disasm(instrument_gen_start, size);
+
+}
+