Fuzz introspector
For issues and ideas: https://github.com/ossf/fuzz-introspector/issues
Project coverage
Per-fuzzer coverage

Table of contents

Project overview: fio
High level conclusions
Reachability and coverage overview
Fuzzers overview
Project functions overview
Fuzzer details
Fuzzer: fuzz_parseini
Call tree
Analyses and suggestions
Optimal target analysis
Remaining optimal interesting functions
All functions overview
Fuzz engine guidance
t/fuzz/fuzz_parseini.c
Dictionary
Fuzzer function priority
Runtime coverage analysis
Files and Directories in report
Files in report
Directories in report
Metadata section
Report generation date: 2026-02-26

Project overview: fio

High level conclusions

Reachability and coverage overview

Functions statically reachable by fuzzers
66.0%
1292 / 1962
Cyclomatic complexity statically reachable by fuzzers
68.0%
8735 / 12790
Runtime code coverage of functions
0.0%
0 / 1962

Fuzzers overview

Fuzzer Fuzzer filename Functions Reached Functions unreached Fuzzer depth Files reached Basic blocks reached Cyclomatic complexity Details
fuzz_parseini t/fuzz/fuzz_parseini.c 1488 717 25 120 23332 9131 fuzz_parseini.c

Project functions overview

The following table shows data about each function in the project. The functions included in this table correspond to all functions that exist in the executables of the fuzzers. As such, there may be functions that are from third-party libraries.

For further technical details on the meaning of columns in the below table, please see the Glossary .

Func name Functions filename Args Function call depth Reached by Fuzzers Runtime reached by Fuzzers Combined reached by Fuzzers Fuzzers runtime hit Func lines hit % I Count BB Count Cyclomatic complexity Functions reached Reached by functions Accumulated cyclomatic complexity Undiscovered complexity

Fuzzer details

Fuzzer: fuzz_parseini

Call tree

The calltree shows the control flow of the fuzzer. This is overlaid with coverage information to display how much of the potential code a fuzzer can reach is in fact covered at runtime. In the following there is a link to a detailed calltree visualisation as well as a bitmap showing a high-level view of the calltree. For further information about these topics please see the glossary for full calltree and calltree overview

Full calltree

Call tree overview bitmap:

The project has no code coverage. Will not display blockers as blockers depend on code coverage.

Analyses and suggestions

Optimal target analysis

Remaining optimal interesting functions

The following table shows a list of functions that are optimal targets. Optimal targets are identified by finding the functions that in combination, yield a high code coverage.

Func name Functions filename Arg count Args Function depth hitcount instr count bb count cyclomatic complexity Reachable functions Incoming references total cyclomatic complexity Unreached complexity
fio_mtd_open_file /src/fio/engines/mtd.c 2 ['N/A', 'N/A'] 35 0 155 25 8 148 0 568 235
fio_handle_clients /src/fio/client.c 1 ['N/A'] 36 0 373 63 22 222 0 863 169
fio_netio_init /src/fio/engines/net.c 1 ['N/A'] 21 0 227 40 16 117 0 457 162
fio_ioring_init /src/fio/engines/io_uring.c 1 ['N/A'] 32 0 578 73 27 128 0 548 145
write_clat_hist_log /src/fio/iolog.c 3 ['N/A', 'int', 'bool'] 37 0 54 9 4 155 0 550 140
fio_mtd_queue /src/fio/engines/mtd.c 2 ['N/A', 'N/A'] 4 0 735 114 33 23 0 144 118
fio_netio_open_file /src/fio/engines/net.c 2 ['N/A', 'N/A'] 37 0 120 18 7 136 0 513 112

Implementing fuzzers that target the above functions will improve reachability such that it becomes:

Functions statically reachable by fuzzers
73.0%
1432 / 1962
Cyclomatic complexity statically reachable by fuzzers
77.0%
9794 / 12790

All functions overview

If you implement fuzzers for these functions, the status of all functions in the project will be:

Func name Functions filename Args Function call depth Reached by Fuzzers Runtime reached by Fuzzers Combined reached by Fuzzers Fuzzers runtime hit Func lines hit % I Count BB Count Cyclomatic complexity Functions reached Reached by functions Accumulated cyclomatic complexity Undiscovered complexity

Fuzz engine guidance

This sections provides heuristics that can be used as input to a fuzz engine when running a given fuzz target. The current focus is on providing input that is usable by libFuzzer.

t/fuzz/fuzz_parseini.c

Dictionary

Use this with the libFuzzer -dict=DICT.file flag


Runtime coverage analysis

No runtime coverage data was found

Files and Directories in report

This section shows which files and directories are considered in this report. The main reason for showing this is fuzz introspector may include more code in the reasoning than is desired. This section helps identify if too many files/directories are included, e.g. third party code, which may be irrelevant for the threat model. In the event too much is included, fuzz introspector supports a configuration file that can exclude data from the report. See the following link for more information on how to create a config file: link

Files in report

Source file Reached by Covered by
[] []
/src/fio/./io_u_queue.h ['fuzz_parseini'] []
/src/fio/lib/flist_sort.c [] []
/src/fio/engines/null.c [] []
/src/fio/libfio.c ['fuzz_parseini'] []
/src/fio/./arch/arch-x86-common.h [] []
/src/fio/engines/e4defrag.c [] []
/src/fio/./os/../flist.h ['fuzz_parseini'] []
/src/fio/profile.c ['fuzz_parseini'] []
/src/fio/dataplacement.c ['fuzz_parseini'] []
/src/fio/./gettime.h ['fuzz_parseini'] []
/src/fio/oslib/libmtd.c [] []
/src/fio/./trim.h ['fuzz_parseini'] []
/src/fio/lib/prio_tree.h [] []
/src/fio/profiles/act.c [] []
/src/fio/engines/../os/../lib/rand.h [] []
/src/fio/lib/ieee754.c ['fuzz_parseini'] []
/src/fio/oslib/linux-dev-lookup.c ['fuzz_parseini'] []
/src/fio/lib/mountcheck.c ['fuzz_parseini'] []
/src/fio/sprandom.c ['fuzz_parseini'] []
/src/fio/flow.c ['fuzz_parseini'] []
/src/fio/./lib/nowarn_snprintf.h ['fuzz_parseini'] []
/src/fio/crc/../lib/bswap.h ['fuzz_parseini'] []
/src/fio/./stat.h ['fuzz_parseini'] []
/src/fio/lib/getrusage.c ['fuzz_parseini'] []
/src/fio/log.c ['fuzz_parseini'] []
/src/fio/lib/axmap.c ['fuzz_parseini'] []
/src/fio/parse.c ['fuzz_parseini'] []
/src/fio/dedupe.c ['fuzz_parseini'] []
/src/fio/lib/num2str.c ['fuzz_parseini'] []
/src/fio/time.c ['fuzz_parseini'] []
/src/fio/smalloc.c ['fuzz_parseini'] []
/src/fio/t/fuzz/fuzz_parseini.c ['fuzz_parseini'] []
/src/fio/lib/lfsr.c ['fuzz_parseini'] []
/src/fio/filesetup.c ['fuzz_parseini'] []
/src/fio/td_error.c ['fuzz_parseini'] []
/src/fio/lib/prio_tree.c [] []
/src/fio/cgroup.c ['fuzz_parseini'] []
/src/fio/lib/rbtree.h ['fuzz_parseini'] []
/src/fio/crc/crc16.h ['fuzz_parseini'] []
/src/fio/ioengines.c ['fuzz_parseini'] []
/src/fio/engines/exec.c [] []
/src/fio/engines/posixaio.c [] []
/src/fio/engines/nvme.c [] []
/src/fio/crc/crc7.h ['fuzz_parseini'] []
/src/fio/engines/ftruncate.c [] []
/src/fio/engines/io_uring.c [] []
/src/fio/lib/bloom.c ['fuzz_parseini'] []
/src/fio/./fifo.h [] []
/src/fio/helper_thread.c ['fuzz_parseini'] []
/src/fio/engines/cmdprio.c [] []
/src/fio/workqueue.c ['fuzz_parseini'] []
/src/fio/lib/memalign.c ['fuzz_parseini'] []
/src/fio/lib/../hash.h ['fuzz_parseini'] []
/src/fio/crc/fnv.c [] []
/src/fio/./iolog.h ['fuzz_parseini'] []
/src/fio/crc/crc32c.c ['fuzz_parseini'] []
/src/fio/./hash.h ['fuzz_parseini'] []
/src/fio/zone-dist.c ['fuzz_parseini'] []
/src/fio/memory.c ['fuzz_parseini'] []
/src/fio/engines/../lib/fls.h [] []
/src/fio/crc/sha3.c ['fuzz_parseini'] []
/src/fio/./lib/seqlock.h ['fuzz_parseini'] []
/src/fio/engines/nvme.h [] []
/src/fio/oslib/libmtd_legacy.c [] []
/src/fio/./os/../io_ddir.h ['fuzz_parseini'] []
/src/fio/crc/sha256.c ['fuzz_parseini'] []
/src/fio/client.c ['fuzz_parseini'] []
/src/fio/crc/crct10dif_common.c [] []
/src/fio/./debug.h ['fuzz_parseini'] []
/src/fio/./lib/pow2.h ['fuzz_parseini'] []
/src/fio/./diskutil.h ['fuzz_parseini'] []
/src/fio/./flist.h ['fuzz_parseini'] []
/src/fio/oslib/strlcat.c [] []
/src/fio/zbd.c ['fuzz_parseini'] []
/src/fio/engines/sync.c [] []
/src/fio/engines/sg.c [] []
/src/fio/cconv.c ['fuzz_parseini'] []
/src/fio/lib/pattern.c ['fuzz_parseini'] []
/src/fio/optgroup.c [] []
/src/fio/crc/crc32.c ['fuzz_parseini'] []
/src/fio/oslib/linux-blkzoned.c ['fuzz_parseini'] []
/src/fio/./crc/crc32c.h ['fuzz_parseini'] []
/src/fio/crc/test.c ['fuzz_parseini'] []
/src/fio/idletime.c ['fuzz_parseini'] []
/src/fio/./verify-state.h ['fuzz_parseini'] []
/src/fio/lib/rand.c ['fuzz_parseini'] []
/src/fio/fio_sem.c ['fuzz_parseini'] []
/src/fio/stat.c ['fuzz_parseini'] []
/src/fio/./arch/arch-x86_64.h ['fuzz_parseini'] []
/src/fio/engines/fileoperations.c [] []
/src/fio/verify.c ['fuzz_parseini'] []
/src/fio/engines/../lib/roundup.h [] []
/src/fio/engines/../os/../file.h [] []
/src/fio/debug.c ['fuzz_parseini'] []
/src/fio/json.c ['fuzz_parseini'] []
/src/fio/lib/hweight.c ['fuzz_parseini'] []
/src/fio/lib/zipf.c ['fuzz_parseini'] []
/src/fio/./os/os-linux.h ['fuzz_parseini'] []
/src/fio/rwlock.c ['fuzz_parseini'] []
/src/fio/./os/../file.h ['fuzz_parseini'] []
/src/fio/fio_shared_sem.c ['fuzz_parseini'] []
/src/fio/fifo.c [] []
/src/fio/lib/output_buffer.c ['fuzz_parseini'] []
/src/fio/lib/rbtree.c ['fuzz_parseini'] []
/src/fio/./pcbuf.h ['fuzz_parseini'] []
/src/fio/engines/net.c [] []
/src/fio/./parse.h ['fuzz_parseini'] []
/src/fio/./io_u.h ['fuzz_parseini'] []
/src/fio/crc/crc32c-intel.c ['fuzz_parseini'] []
/src/fio/engines/splice.c [] []
/src/fio/trim.c ['fuzz_parseini'] []
/src/fio/eta.c ['fuzz_parseini'] []
/src/fio/crc/crc64.c ['fuzz_parseini'] []
/src/fio/lib/memcpy.c ['fuzz_parseini'] []
/src/fio/oslib/libmtd_xalloc.h [] []
/src/fio/rate-submit.c ['fuzz_parseini'] []
/src/fio/./zbd.h ['fuzz_parseini'] []
/usr/include/x86_64-linux-gnu/asm/swab.h [] []
/src/fio/profiles/tiobench.c [] []
/src/fio/blktrace.c ['fuzz_parseini'] []
/src/fio/lib/strntol.c [] []
/src/fio/iolog.c ['fuzz_parseini'] []
/src/fio/engines/mtd.c [] []
/src/fio/io_u_queue.c ['fuzz_parseini'] []
/src/fio/engines/../fio.h [] []
/src/fio/backend.c ['fuzz_parseini'] []
/src/fio/lib/gauss.c ['fuzz_parseini'] []
/src/fio/engines/falloc.c [] []
/src/fio/io_u.c ['fuzz_parseini'] []
/src/fio/./os/../lib/rand.h ['fuzz_parseini'] []
/src/fio/engines/../os/os-linux.h [] []
/src/fio/gettime-thread.c ['fuzz_parseini'] []
/src/fio/crc/xxhash.c ['fuzz_parseini'] []
/src/fio/crc/crc7.c ['fuzz_parseini'] []
/src/fio/options.c ['fuzz_parseini'] []
/src/fio/./workqueue.h ['fuzz_parseini'] []
/src/fio/pshared.c ['fuzz_parseini'] []
/src/fio/./options.h ['fuzz_parseini'] []
/src/fio/crc/sha1.c ['fuzz_parseini'] []
/src/fio/gettime.c ['fuzz_parseini'] []
/src/fio/filehash.c ['fuzz_parseini'] []
/src/fio/steadystate.c ['fuzz_parseini'] []
/src/fio/./lib/rbtree.h ['fuzz_parseini'] []
/src/fio/crc/crc16.c ['fuzz_parseini'] []
/src/fio/crc/murmur3.c [] []
/src/fio/engines/../os/../io_ddir.h [] []
/src/fio/engines/cpu.c [] []
/src/fio/engines/mmap.c [] []
/src/fio/diskutil.c ['fuzz_parseini'] []
/src/fio/./fio.h ['fuzz_parseini'] []
/usr/include/linux/swab.h [] []
/src/fio/init.c ['fuzz_parseini'] []
/src/fio/crc/md5.c ['fuzz_parseini'] []
/src/fio/./err.h ['fuzz_parseini'] []
/src/fio/filelock.c [] []
/src/fio/./json.h ['fuzz_parseini'] []
/src/fio/server.c ['fuzz_parseini'] []
/src/fio/crc/sha512.c ['fuzz_parseini'] []
/src/fio/./os/os.h ['fuzz_parseini'] []

Directories in report

Directory
/src/fio/./
/src/fio/crc/../lib/
/src/fio/
/src/fio/./lib/
/src/fio/engines/../os/../
/src/fio/profiles/
/src/fio/./os/../lib/
/src/fio/lib/
/src/fio/crc/
/src/fio/engines/
/src/fio/engines/../
/src/fio/./crc/
/src/fio/engines/../os/
/src/fio/./os/
/src/fio/oslib/
/src/fio/./os/../
/src/fio/./arch/
/src/fio/lib/../
/src/fio/engines/../os/../lib/
/src/fio/t/fuzz/
/usr/include/x86_64-linux-gnu/asm/
/src/fio/engines/../lib/
/usr/include/linux/

Metadata section

This sections shows the raw data that is used to produce this report. This is mainly used for further processing and developer debugging.

Fuzzer Calltree file Program data file Coverage file
fuzz_parseini fuzzerLogFile-0-77oU5HexQS.data fuzzerLogFile-0-77oU5HexQS.data.yaml