Noteworthy changes in strace 5.8 (2020-08-06)
=============================================

* Changes in behaviour
  * Modified %process class to contain system calls associated with
    process lifecycle (creation, exec, termination):
    kill, tkill, tgkill, pidfd_send_signal and rt_sigqueueinfo are added,
    arch_prctl and unshare are removed.

* Improvements
  * Implemented decoding of faccessat2 syscall.
  * Implemented decoding of LOOP_CONFIGURE ioctl command.
  * Updated decoding of io_uring_setup syscall to match Linux 5.8.
  * Updated lists of AUDIT_*, BPF_*, CAP_*, ETH_*, INET_DIAG_*, IORING_*,
    KEYCTL_*, KVM_*, LOOP_*, NDA_*, RTC_*, TCA_*, STATX_*, and *_MAGIC
    constants.
  * Updated lists of ioctl commands from Linux 5.8.

* Bug fixes
  * Added statx syscall to %fstat trace class.

Contributors
============

This release was made possible by the contributions of many people.
The maintainers are grateful to everyone who has contributed
changes or bug reports.  These include:

* Chris Packham
* Dmitry V. Levin
* Eugene Syromyatnikov
* Gleb Fotengauer-Malinovskiy
* Janosch Frank
* Steve Langasek
* Sven Schnelle
* Ákos Uzonyi

Please refer to the CREDITS file for the full list of strace contributors.

Noteworthy changes in strace 5.7 (2020-06-01)
=============================================

* Improvements
  * Implemented interval specification in "when=" subexpression of syscall
    tampering expressions.
  * Added -e trace=%clock option for tracing syscalls reading of modifying
    system clocks.
  * Implemented decoding of BPF_LINK_CREATE and BPF_LINK_UPDATE bpf
    syscall commands.
  * Updated decoding of clone3 syscall to match Linux 5.7.
  * Updated lists of BPF_*, BTRFS_*, CLONE_*, FAN_*, IORING_*, KVM_*,
    LWTUNNEL_*, MREMAP_*, PERF_*, SECCOMP_*, UFFDIO_*, V4L2_*, and XDP_*
    constants.
  * Updated lists of ioctl commands from Linux 5.7.

* Bug fixes
  * Fixed decoding of getdents and getdents64 syscalls when they return
    a lot of directory entries.
  * Fixed pathtrace matching of openat2 syscall.
  * Fixed build on systems without fork.

Contributors
============

This release was made possible by the contributions of many people.
The maintainers are grateful to everyone who has contributed
changes or bug reports.  These include:

* Alistair Francis
* Dmitry V. Levin
* Eugene Syromyatnikov
* Fabrice Fontaine
* Gleb Fotengauer-Malinovskiy
* Kemeng Shi
* Maxim Akhmedov
* Mike Gilbert
* Niklas Cathor
* Paul Chaignon
* Pierre Marsais
* Ákos Uzonyi

Please refer to the CREDITS file for the full list of strace contributors.

Noteworthy changes in strace 5.6 (2020-04-07)
=============================================

* Changes in behaviour
  * Messages about unknown tracees are now subject to the strace's quietness
    setting (-q/--quiet).
  * If -A option is provided without -o, or -S option without -c/-C, a warning
    about its uselessness is printed now.
  * The usage of --seccomp-bpf without -f has no effect now.

* Improvements
  * Every short option now has a long option alias, which also has enabled
    the following improvements:
    * Ability to use human-readable settings for -I/--interruptible,
      -D/--daemonize options.
    * Ability to silence specific messages using -e quiet/--quiet qualifier
      (an alias for the -q option), including those that couldn't be silenced
      previously (path resolution messages and "superseded by execve").
    * Ability to specify selected fd decoding features using
      -e decode-fds/--decode-fds qualifier (an alias for the -y option).
    * Ability to set precision for the absolute timestamp, relative timestamp,
      and syscall time output (using --absolute-timestamps,
      --relative-timestamps, and --syscall-times options, respectively).
  * Implemented ability to select the set of displayed columns in the call
    summary output (-U/--summary-columns option).
  * Implemented ability to sort on any summary column.
  * Implemented ability to show information about minimum and maximum call
    duration in the call summary output (addresses Debian bug #240945).
  * Implemented printing of PIDs associated with pidfds in -yy mode.
  * Implemented PTRACE_GETREGS API support on hppa, sh, sh64, and xtensa.
  * Improved performance of libdw-based stack traces printing by implementing
    a symbol-to-address cache.
  * Implemented decoding of openat2 and pidfd_getfd syscalls.
  * Enhanced io_uring_register, prctl, sched_getattr, and sched_setattr syscall
    decoding.
  * Implemented decoding of BPF_MAP_LOOKUP_BATCH,
    BPF_MAP_LOOKUP_AND_DELETE_BATCH, BPF_MAP_UPDATE_BATCH, and
    BPF_MAP_DELETE_BATCH bpf syscall commands.
  * Enhanced decoding of BPF_MAP_CREATE and BPF_PROG_ATTACH bpf syscall
    commands.
  * Enhanced decoding of RTC_VL_READ ioctl command.
  * Enhanced decoding of IFLA_* netlink attributes.
  * Implemented HIDIOCGRAWUNIQ() ioctl command number printing.
  * Wired up kexec_file_load syscall on hppa.
  * Updated lists of AUDIT_*, BPF_*, CLONE_*, GRND_*, IFLA_*, IORING_*,
    IPPROTO_*, KEY_*, KVM_*, RTM_F_*, SCHED_*, and *_MAGIC constants.
  * Updated lists of ioctl commands from Linux 5.6.

* Bug fixes
  * Fixed build on csky abiv1 architecture.
  * Various minor fixes in VIDIOC_* ioctl output formatting.
  * Fix printing of the size field for _IOC_NONE ioctl command numbers on sparc.

* Portability
  * On hppa, linux kernel >= 4.7 is required.
    On sh and sh64, linux kernel >= 2.6.28 is required.
    Older versions without a decent PTRACE_GETREGS support will not work.

Contributors
============

This release was made possible by the contributions of many people.
The maintainers are grateful to everyone who has contributed
changes or bug reports.  These include:

* Alistair Francis
* Dmitry V. Levin
* Eugene Syromyatnikov
* Gleb Fotengauer-Malinovskiy
* Jann Horn
* Ma Jun
* Masatake YAMATO
* Paul Chaignon
* Philippe De Muyter

Please refer to the CREDITS file for the full list of strace contributors.

Noteworthy changes in strace 5.5 (2020-02-06)
=============================================

* Improvements
  * Added -e trace=%creds option for tracing syscalls related to process
    credentials.
  * Enhanced decoding of arch_prctl, keyctl, io_uring_register, io_uring_setup,
    and perf_event_open syscalls.
  * Enhanced decoding of BPF_PROG_LOAD bpf syscall command.
  * Updated decoding of clone3 syscall to match Linux 5.5.
  * Implemented decoding of TCA_ACT_FLAGS and TCA_STATS_PKT64 netlink
    attributes.
  * Updated lists of AUDIT_*, BPF_*, CLONE_*, KEY_*, KVM_*, PPC_PTRACE_*,
    SCTP_*, STATX_*, TIPC_*, V4L2_*, and *_MAGIC constants.
  * Updated lists of ioctl commands from Linux 5.5.
  * Enhanced manual page and "strace --help" output.

* Bug fixes
  * Fixed stack trace printing for early syscalls when strace is configured
    to use libdw backend for stack tracing (addresses Fedora bug #1788636).
  * Fixed stack trace caching when --seccomp-bpf option is specified.
  * Fixed potentially unaligned access in decoder of SO_TIMESTAMP*_NEW
    control messages.
  * Fixed decoding of NDA_LLADDR netlink neighbor table attribute.
  * Fixed build of mpers support when CFLAGS contains -flto.
  * Fixed build on no-MMU architectures.
  * Fixed build with glibc-2.31 and Linux kernel headers < 5.3.
  * Fixed tests for glibc-2.31.

Contributors
============

This release was made possible by the contributions of many people.
The maintainers are grateful to everyone who has contributed
changes or bug reports.  These include:

* Andreas Schwab
* Andrey Zax
* Baruch Siach
* Chunmei Xu
* Dmitry V. Levin
* Eugene Syromyatnikov
* Gleb Fotengauer-Malinovskiy
* Jamal Hadi Salim
* Khem Raj
* Paul Chaignon
* Pavel Zhukov
* Quentin Monnet
* Rich Felker
* Thomas Deutschmann
* Vineet Gupta
* Vladimir D. Seleznev

Please refer to the CREDITS file for the full list of strace contributors.

Noteworthy changes in strace 5.4 (2019-11-28)
=============================================

* Improvements
  * Implemented -DD and -DDD options that move strace into a separate
    process group and session, respectively.
  * Enhanced seccomp-bpf tracee syscall filtering support by implementing
    new "binary match" BPF program generation strategy and automatically
    choosing the strategy that generates the shortest BPF program.
  * Implemented decoding of BPF_BTF_GET_NEXT_ID bpf syscall command.
  * Enhanced decoding of BPF_MAP_LOOKUP_ELEM bpf syscall command.
  * Implemented PTP_CLOCK_GETCAPS2, PTP_EXTTS_REQUEST2, PTP_PEROUT_REQUEST2,
    PTP_ENABLE_PPS2, and PTP_SYS_OFFSET2 ioctl decoding.
  * Updated lists of BPF_*, CAN_*, KEXEC_*, KVM_*, MADV_*, MSG_*, P_*, PR_*,
    PTP_*, SCTP_*, and V4L2_* constants.
  * Implemented ability to build ARM EABI mpers support using a separate
    compiler on aarch64.
  * Updated lists of ioctl commands from Linux 5.4.
  * Enhanced manual page.

* Bug fixes
  * Fixed -b execve when --seccomp-bpf option is specified.
  * Fixed decoding of BPF_PROG_LOAD bpf syscall command.
  * Fixed build on no-MMU architectures.
  * Fixed build on antique systems that do not provide necessary definitions
    of AUDIT_ARCH_* constants.

Contributors
============

This release was made possible by the contributions of many people.
The maintainers are grateful to everyone who has contributed
changes or bug reports.  These include:

* Andreas Schwab
* Baruch Siach
* Dmitry V. Levin
* Elvira Khabirova
* Eugene Syromyatnikov
* Fanda Uchytil
* Gleb Fotengauer-Malinovskiy
* Paul Chaignon

Please refer to the CREDITS file for the full list of strace contributors.

Noteworthy changes in strace 5.3 (2019-09-25)
=============================================

* Improvements
  * Implemented usage of seccomp-bpf for stopping tracees only for filtered
    syscalls.  Use --seccomp-bpf option to enable.
  * Implemented decoding of pidfd_open and clone3 syscalls.
  * Enhanced decoding of io_cancel, io_submit, s390_sthyi, and syslog syscalls.
  * Enhanced decoding of NETLINK_ROUTE protocol.
  * Implemented decoding of UNIX_DIAG_UID netlink attribute.
  * Implemented decoding of WDIOC_* ioctl commands.
  * Enchanced syscall count statistics: overhead is now applied per-call,
    added ability for sorting on errors field.
  * Syscall delay injection and overhead values can now be supplied with
    time measure unit suffix and provided in IEEE 754 floating point format.
  * Updated lists of AUDIT_*, BPF_*, ETH_*, KEYCTL_*, KVM_*, MAP_*, SO_*, TCP_*, V4L2_*,
    XDP_*, and *_MAGIC constants.
  * Updated lists of ioctl commands from Linux 5.3.
  * Enhanced manual page.

* Bug fixes
  * Fixed syscall tampering on arc, avr32, csky, ia64, m68k, metag, mips,
    nios2, or1k, riscv, s390, s390x, sparc, sparc64, and tile architectures
    when PTRACE_GET_SYSCALL_INFO is in use.
  * Fixed decoding of sockaddr_hci (AF_BLUETOOTH) addresses that lack
    hci_channel field.
  * Fixed evdev ioctl bitset decoding.
  * Fixed tests on alpha with Linux kernel headers 5.1+.

* Portability
  * Removed support for decoding syscalls in range [1024...1079] on AArch64
    architecture as this range has never been implemented in mainline kernel
    releases.

Contributors
============

This release was made possible by the contributions of many people.
The maintainers are grateful to everyone who has contributed
changes or bug reports.  These include:

* Alexey Gladkov
* Anatoly Pugachev
* Bharath Vedartham
* Chen Jingpiao
* Dan Horák
* Dmitry V. Levin
* Eugene Syromyatnikov
* Gleb Fotengauer-Malinovskiy
* Jeremy Kerr
* Paul Chaignon
* Pierre Marsais
* Rasmus Villemoes

Please refer to the CREDITS file for the full list of strace contributors.

Noteworthy changes in strace 5.2 (2019-07-12)
=============================================

* Improvements
  * Implemented syscall return status filtering with -e status=set option
    and its aliases: -z (limit syscall printing to successful syscalls only)
    and -Z (limit syscall printing to failed syscalls only).
  * Implemented decoding of open_tree, move_mount, fsopen, fsconfig, fsmount,
    and fspick syscalls.
  * Enhanced decoding of bpf, clone, inotify_init, mbind, and set_mempolicy
    syscalls.
  * Updated lists of AT_*, AUDIT_*, BPF_*, CLONE_*, ETH_*, KEY_*, KVM_*, MPOL_*,
    TIPC_*, and V4L2_* constants.
  * Updated lists of ioctl commands from Linux 5.2.

* Bug fixes
  * Fixed syscall tampering on powerpc, powerpc64, sparc, and sparc64 when
    PTRACE_GET_SYSCALL_INFO is in use.
  * Fixed build with cutting-edge toolchain.

Contributors
============

This release was made possible by the contributions of many people.
The maintainers are grateful to everyone who has contributed
changes or bug reports.  These include:

* Burkhard Kohl
* Dmitry V. Levin
* Eugene Syromyatnikov
* Gleb Fotengauer-Malinovskiy
* Masatake YAMATO
* Michal Sekletar
* Paul Chaignon
* Zhibin Li

Please refer to the CREDITS file for the full list of strace contributors.

Noteworthy changes in strace 5.1 (2019-05-22)
=============================================

* Bug fixes
  * Fixed decoding of last two arguments of clone syscall on riscv.

* Improvements
  * Added C-SKY architecture support.
  * Implemented decoding of SO_TIMESTAMP*_NEW control messages.
  * Implemented decoding of clock_gettime64, clock_settime64, clock_adjtime64,
    clock_getres_time64, clock_nanosleep_time64, timer_gettime64,
    timer_settime64, timerfd_gettime64, timerfd_settime64, utimensat_time64,
    pselect6_time64, ppoll_time64, io_pgetevents_time64, recvmmsg_time64,
    mq_timedsend_time64, mq_timedreceive_time64, semtimedop_time64,
    rt_sigtimedwait_time64, futex_time64, sched_rr_get_interval_time64,
    pidfd_send_signal, io_uring_setup, io_uring_enter, and io_uring_register
    syscalls.
  * Enhanced decoding of bpf syscall.
  * Wired up getegid, geteuid, getppid, io_pgetevents, statfs64, and fstatfs64
    syscalls on alpha.
  * Wired up kexec_file_load and migrate_pages syscalls on arm.
  * Wired up io_pgetevents, perf_event_open, seccomp, and statx syscalls
    on ia64.
  * Wired up seccomp syscall on m68k.
  * Wired up statx syscall on sh.
  * Wired up pkey_mprotect, pkey_alloc, and pkey_free syscalls on alpha, hppa,
    ia64, m68k, s390, s390x, sh, sparc, and sparc64.
  * Wired up rseq syscall on alpha, hppa, ia64, m68k, sh, sparc, sparc64,
    and xtensa.
  * Wired up direct ipc syscalls on m68k, mips o32, powerpc, powerpc64,
    s390, s390x, sh, sparc, sparc64, and x86.
  * Updated lists of BPF_*, FAN_*, F_SEAL_*, IPV6_*, NT_*, PR_SPEC_*, SO_*,
    and V4L2_* constants.
  * Updated lists of ioctl commands from Linux 5.1.

Contributors
============

This release was made possible by the contributions of many people.
The maintainers are grateful to everyone who has contributed
changes or bug reports.  These include:

* Dmitry V. Levin
* Eugene Syromyatnikov
* Gleb Fotengauer-Malinovskiy
* Guo Ren

Please refer to the CREDITS file for the full list of strace contributors.

Noteworthy changes in strace 5.0 (2019-03-19)
=============================================

* Changes in behavior
  * -D option now implies -I4: by default strace ignores SIGHUP, SIGINT,
    SIGQUIT, SIGPIPE, SIGTERM, SIGTTIN, SIGTTOU, and SIGTSTP when -D option
    is used.
  * Diagnostic message is no longer printed if an attempt to restart a process
    has failed with ESRCH.  (Addresses RHBZ bug #1662936.)
  * ASCII dump no longer tries to read the whole buffer at once.  As result,
    it can fail with a diagnostic message after dumping only a part.
    Amount of preceding zeroes printed for offset is now chosen in a way
    to accommodate all the digits of all the offsets being printed.

* Improvements
  * Changed the way tracees are handled: all pending tracees are now waited for
    before further processing, this improves fairness of tracee processing.
    (Addresses RHBZ bugs #478419, #526740, #851457, #1609318, #1610774,
    and maybe some others.)
  * Enhanced xlat styles support configured by -X option.
  * Enhanced decoding of bpf syscall.
  * Enhanced decoding of PTRACE_PEEKUSER and PTRACE_POKEUSER on hppa.
  * Enhanced pid formatting in strace-log-merge output.
  * Wired up kexec_file_load and rseq syscalls on aarch64, arc, metag, nios2,
    or1k, riscv, and tile architectures.
  * Updated lists of BPF_*, BTRFS_*, FAN_*, IFLA_*, KERN_*, KVM_CAP_*, NDA_*,
    NETNSA_*, NT_*, PR_*, REL_*, SECCOMP_*, SCTP_*, UDP_*, V4L2_*, and *_MAGIC
    constants.
  * Updated lists of ioctl commands from Linux 5.0.

* Bug fixes
  * Fixed ordering of sockaddr_in6 fields.
  * Fixed strace-k test on alpha.
  * Fixed build on mips o32.
  * Fixed build on NOMMU architectures.
  * Fixed build in --with-libiberty=yes mode.
  * Fixed potential NULL dereference during printing of line continuation
    for syscalls that haven't been decoded.
  * Fixed strace-log-merge error diagnostics.

Contributors
============

This release was made possible by the contributions of many people.
The maintainers are grateful to everyone who has contributed
changes or bug reports.  These include:

* Andreas Schwab
* Baruch Siach
* DJ Delorie
* Denys Vlasenko
* Dmitry V. Levin
* Eugene Syromyatnikov
* Gleb Fotengauer-Malinovskiy
* Jeff Law
* Martin Lau
* Shankara Pailoor
* Tuan Hoang

Please refer to the CREDITS file for the full list of strace contributors.

Noteworthy changes in strace 4.26 (2018-12-26)
==============================================

* License
  * The test suite is now provided under the terms of
    the GNU General Public License version 2 or later.
  * All the rest of strace is now provided under the terms of
    the GNU Lesser General Public License version 2.1 or later.

* Changes in behavior
  * If strace is interrupted by a signal it handles (currently
    one of HUP, INT, QUIT, PIPE, or TERM), strace terminates
    itself with this signal.

* Improvements
  * Implemented obtainment of system call information using
    PTRACE_GET_SYSCALL_INFO ptrace API.
  * Implemented decoding of PTRACE_GET_SYSCALL_INFO ptrace request.
  * Implemented decoding of BLKGETZONESZ, BLKGETNRZONES, and RND* ioctl
    commands.
  * Enhanced xlat styles support configured by -X option.
  * Enhanced internet address formatting in structureless contexts.
  * Enhanced decoding of getsockopt SO_ERROR option.
  * Enhanced error diagnostics when the first exec fails.
  * Added %net as a short form of %network in syscall specifications.
  * Updated lists of ABS_*, BPF_*, FAN_*, IFA_*, IFLA_*, KVM_CAP_*, NETLINK_*,
    NTF_*, PR_SPEC_*, REL_*, SOL_*, TCA_*, and V4L2_* constants.
  * Updated lists of ioctl commands from Linux 4.20.
  * Enhanced manual page.

* Bug fixes
  * Fixed "xlat_idx: Unexpected xlat value 0" warnings.
  * Fixed sthyi output format on s390.
  * Documented -X option in strace -h output.

Contributors
============

This release was made possible by the contributions of many people.
The maintainers are grateful to everyone who has contributed
changes or bug reports.  These include:

* Dmitry V. Levin
* Dmitry Vyukov
* Eugene Syromyatnikov
* Gleb Fotengauer-Malinovskiy
* Jamal Hadi Salim
* Janosch Frank
* Masatake YAMATO
* Rasmus Villemoes
* Shankara Pailoor

Please refer to the CREDITS file for the full list of strace contributors.

Noteworthy changes in strace 4.25 (2018-10-30)
==============================================

* Improvements
  * Implemented decoding of KVM_CHECK_EXTENSION and NBD_* ioctl commands.
  * Implemented decoding of SOL_XDP socket option names.
  * Implemented decoding of AF_PACKET protocols in socket syscall.
  * Implemented decoding of AF_AX25 and AF_X25 addresses, protocols,
    and options.
  * Implemented stack trace printing on receiving signals.
  * Enhanced xlat styles support configured by -X option.
  * Enhanced decoding of IFLA_*, NETCONFA_*, and SMC_DIAG_* netlink attributes.
  * Wired up io_pgetevents syscall on arm, sparc, and sparc64.
  * Updated lists of AF_*, AUDIT_*, BPF_*, IFLA_*, IN_*, IPSTATS_*,
    IPV4_DEVCONF_*, NT_*, SCTP_*, SO_*, SOCK_*, SOL_*, and V4L2_* constants.
  * Updated lists of ioctl commands from Linux 4.19.

* Bug fixes
  * Fixed decoding of bit sets in evdev ioctl commands.
  * Fixed decoding of EVIOCGBIT(0, ...) ioctl commands.
  * Fixed test suite for the case when mlockall and unimplemented syscalls
    are explicitly disabled by a seccomp filter.

Contributors
============

This release was made possible by the contributions of many people.
The maintainers are grateful to everyone who has contributed
changes or bug reports.  These include:

* Dmitry V. Levin
* Elvira Khabirova
* Eugene Syromyatnikov
* Gleb Fotengauer-Malinovskiy
* Pierre Marsais
* Zhibin Li

Please refer to the CREDITS file for the full list of strace contributors.

Noteworthy changes in strace 4.24 (2018-08-14)
==============================================

* Improvements
  * Implemented decoding of kvm vcpu exit reason (-e kvm=vcpu option),
    requires Linux kernel version 4.16.0 or higher.
  * Implemented decoding of KVM_SET_CPUID2 and KVM_GET_*_CPUID ioctl commands.
  * Enhanced decoding of corner cases of SO_LINGER, SO_PEERCRED,
    and PACKET_STATISTICS getsockopt options.
  * Wired up io_pgetevents and rseq syscalls on hppa, microblaze, mips, powerpc,
    and s390.
  * Updated lists of AUDIT_*, BPF_*, IFA_*, IFLA_*, RTA_*, RTPROT_*, TCP_*,
    TRAP_*, and UDP_* constants.
  * Updated lists of ioctl commands from Linux 4.18.

* Bug fixes
  * Fixed decoding of Q_XGETQSTAT on non-native personalities.
  * Fixed race condition in aio test.
  * Fixed build with Bionic libc.
  * Fixed build with glibc-2.28.
  * Fixed build in exotic systemd-nspawn based environments.
  * Fixed build on s390 with kernel headers that do not contain Linux commit
    v3.10-rc1~201^2~11.

Contributors
============

This release was made possible by the contributions of many people.
The maintainers are grateful to everyone who has contributed
changes or bug reports.  These include:

* Chen Jingpiao
* Dmitry V. Levin
* Elliott Hughes
* Eugene Syromyatnikov
* Gleb Fotengauer-Malinovskiy
* Masatake YAMATO
* Pierre Marsais
* Zhibin Li

NEWS for strace version 4.23
============================

* Changes in behaviour
  * On x32 personality, 64-bit syscalls (such as readv) are now shown with "#64"
    suffix instead of "64:" prefix.  Unlike the old names, these new names
    can be used in syscall qualification expressions.
  * Changed error number output format: error numbers are consistently
    printed as "-1 ECONST (Error description)"
    for known errors and as "-1 (errno 123)" for unknown errors,
    regardless of -e raw qualification settings.  One can specify
    -X raw for displaying raw error numbers unconditionally.
  * Unfetchable addresses inside arrays are now printed as comments.
  * Obsolete IA-32 mode syscall names are no longer printed on ia64.

* Improvements
  * Implemented libdw backend for -k option, configured at build time
    using --with-libdw option.
    Whether -k option is compiled is now configured at build time
    using --enable-stacktrace option.
  * Added -X option for configuring xlat output formatting (addresses
    Debian bug #692915).
  * Added support for personality designation ("64", "32", or "x32") to syscall
    qualifications in -e trace expressions.
  * Implemented injection of syscalls with no side effects as an alternative
    to injection of an invalid syscall (-e inject=SET:syscall= expression).
  * Improved support for reproducible builds (addresses Debian bug #896016).
  * Implemented decoding of BPF_PROG_QUERY and BPF_RAW_TRACEPOINT_OPEN bpf
    syscall commands.
  * Implemented decoding of INOTIFY_IOC_SETNEXTWD and PERF_EVENT_IOC_* ioctl
    commands.
  * Implemented decoding of PR_GET_SPECULATION_CTRL and PR_SET_SPECULATION_CTRL
    prctl syscall options.
  * Enhanced decoding of bpf, getsockopt, setsockopt, and socket syscalls.
  * Enhanced decoding of NETLINK_KOBJECT_UEVENT and NETLINK_ROUTE protocols.
  * Enhanced decoding of *_DIAG_MEMINFO netlink attributes.
  * Enhanced decoding of BTRFS_*, FS_IOC_*, SIOCGIFHWADDR, and SIOCSIFHWADDR
    ioctl commands.
  * Enhanced decoding of AF_BLUETOOTH socket addresses.
  * Implemented decoding of io_pgetevent syscall.
  * Wired up rseq syscall.
  * Updated lists of ADJ_*, BPF_*, BPF_F_*, BPF_PROG_TYPE_*, ETH_P_*, FPE_*,
    IFF_*, IPPROTO_*, MAP_*, MS_*, MSG_*, NETLINK_*, PACKET_*, PROT_*, SCTP_*,
    SECCOMP_FILTER_FLAG_*, SEGV_*, SEM_*, SHM_*, SW_*, V4L2_CID_*,
    V4L2_CTRL_CLASS_*, and V4L2_PIX_FMT_* constants.
  * Updated lists of ioctl commands from Linux 4.17.

* Bug fixes
  * Fixed decoding of msgtyp argument of msgrcv syscall.
  * Fixed fallback definitions for F_*, MCL_*, MSG_ZEROCOPY, SI_*,
    and SOL_SOCKET constants.
  * Fixed -e trace=%pure expression on mips.

Contributors
============

This release was made possible by the contributions of many people.
The maintainers are grateful to everyone who has contributed
changes or bug reports.  These include:

* Andre McCurdy
* Chris Lamb
* Dmitry V. Levin
* Eugene Syromyatnikov
* Gleb Fotengauer-Malinovskiy
* Harsha Sharma
* Mark Wielaard
* Masatake YAMATO
* Zhibin Li

NEWS for strace version 4.22
============================

* Changes in infrastructure
  * The mailing list was moved to strace-devel@lists.strace.io.
  * SourceForge git repository
    (https://sourceforge.net/p/strace/code/ci/master/tree/) is no longer
    maintained.  Please use GitLab (https://gitlab.com/strace/strace/)
    or GitHub (https://github.com/strace/strace/) repository instead.

* Changes in behaviour
  * When printing string data, '8' and '9' following an octal escape sequence
    no longer lead to unabbreviated octal escape sequence output, as they used
    to do.
  * Angle brackets are now printed as octal number escape sequences
    in the output of paths associated with file descriptors.
  * Data dump for write syscalls (-e write) is performed regardless
    of successfulness of these syscall (addresses Debian bug #436284).
  * -r and -t options are now affect output independently.  Previously,
    -r option led to ignoring of the -t option (addresses Debian bug #466195).

* Improvements
  * Implemented delay injection (-e inject=SET:delay_enter= and
    -e inject=SET:delay_exit= options).
  * Added -A option for opening output files in append mode
    (addresses Debian bug #528488).
  * IPv6 addresses shown in socket information in -yy mode are now printed
    in brackets.
  * Enhanced decoding of bpf, prctl and ptrace syscalls.
  * Enhanced decoding of BTRFS_IOC_INO_PATHS, BTRFS_IOC_LOGICAL_INO, and PTP_*
    ioctl commands.
  * Enhanced NETLINK_ROUTE protocol decoding.
  * Updated lists of signal codes.
  * Updated lists of BPF_*, BTN_*, ETH_P_*, INET_DIAG_BC_*, KEY_*, POLL*, RWF_*,
    SCHED_FLAG_*, SCTP_* and error constants.
  * Implemented block/character device number printing in -yy mode.
  * Known pixel/SDR format names are printed as comments for pixelformat fields
    in v4l2 structures.
  * Enhanced decoding of kern_features syscall.
  * Enhanced NETLINK_NETFILTER netlink protocol decoder.
  * Optimized handling of large number of tracees.
  * Improved wall clock time measurement in syscall count statistics
    (-c -w option).
  * Extended the range of allowed values in -e inject=...:retval= expression.
  * Added i18n support.
  * Updated lists of ioctl commands from Linux 4.16.
  * Enhanced manual page.

* Bug fixes
  * Fixed build on m68k.
  * Fixed v4l2 pixelformat decoding on big-endian architectures.
  * Fixed -O option.

Contributors
============

This release was made possible by the contributions of many people.
The maintainers are grateful to everyone who has contributed
changes or bug reports.  These include:

Chen Jingpiao
Dmitry V. Levin
Elvira Khabirova
Eugene Syromyatnikov
Gleb Fotengauer-Malinovskiy
Harsha Sharma
J. Bruce Fields
Josh Triplett
Masatake YAMATO
Philipp Marek

NEWS for strace version 4.21
============================

* Changes in behaviour
  * Warning is now issued when -F option is used.
  * Warning is now issued when a tracee with unsupported personality
    is attached.
  * Unknown syscall numbers are now printed in hexadecimal form.

* Improvements
  * Implemented decoding of netlink descriptor attributes as file descriptors.
  * Implemented decoding of hugetlb page size selection flags.
  * Implemented decoding of BPF_PROG_TEST_RUN, BPF_PROG_GET_NEXT_ID,
    BPF_MAP_GET_NEXT_ID, BPF_PROG_GET_FD_BY_ID, BPF_MAP_GET_FD_BY_ID,
    and BPF_OBJ_GET_INFO_BY_FD commands of bpf syscall.
  * Enhanced decoding of get_thread_area, memfd_create, modify_ldt,
    perf_event_open, reboot, s390_guarded_storage, s390_pcio_mmio_read,
    s390_pci_mmio_write, s390_runtime_instr, s390_sthyi, set_thread_area,
    and shmget syscalls.
  * Implemented decoding of KVM_* and DM_LIST_DEVICES ioctl commands.
  * Implemented decoding of riscv_flush_icache syscall.
  * Enhanced decoding of getsockopt and setsockopt syscalls for SOL_NETLINK
    level.
  * Enhanced decoding of BPF_MAP_CREATE command of bpf syscall.
  * Print values returned by mq_open syscall and first arguments
    of mq_getsetattr, mq_notify, mq_timedreceive, and mq_timedsend syscalls
    as file descriptors.
  * Added decoding of get_tls syscall on arm.
  * Added -e trace=%pure option for tracing system calls with no arguments that
    never fail.
  * Updated lists of IPV6_*, MAP_*, MEMBARRIER_CMD_*, MSG_*, NT_*, PKEY_*,
    SHM_*, and TCP_* constants.
  * Added manual page for the strace-log-merge command.
  * Updated lists of ioctl commands from Linux 4.15.
  * Implemented biarch support for s390x.
  * Implemented an optional support for symbol demangling in strace -k output
    (activated by --with-libiberty configure option).
  * Information about availability of demangling and reliable personality
    decoding (on architectures with multiple personalities) is now available
    in strace -V output.
  * Added decoding of pkey_alloc, pkey_free, and pkey_mprotect syscalls on
    powerpc and powerpc64.
  * Enhanced manual page.

* Bug fixes
  * Fixed multi-personality support in cross builds.
  * Added mq_getsetattr, mq_notify, mq_open, mq_timedreceive, and mq_timedsend
    syscalls to %desc tracing set.
  * Fixed path tracing support for mmap syscalls with indirect arguments and
    for old select syscall.
  * Fixed decoding of arm-specific (__ARM_NR_*) syscalls.
  * Fixed open mode flags decoding.
  * Fixed corner cases in handling of strace -ff -ttt logs by strace-log-merge.
  * Error counts that exceed one billion are now printed correctly in call
    summary output.
  * Fixed call summary header for x32 personality.
  * Changes of tracee personalities are reported more reliably.
  * Fixed the case when strace attaches to a tracee being inside exec and its
    first syscall stop is syscall-exit-stop instead of syscall-enter-stop,
    which messed up all the syscall state tracking.
  * Fixed printing of higher 32 bits of the return value for x32 personality.

* Portability
  * A C compiler that supports "for" loop initial declarations is now required.
  * Inability to configure multiple personality support on architectures where
    multiple personalities are supported leads to configuration failure during
    build now.  Use --enable-mpers=check to revert to the old behaviour.
  * Build-time requirement for the mpers support has been lowered from gawk 4
    to gawk 3.
  * Removed incomplete and non-functional support for the CRIS architecture.
  * Removed incomplete and unused support for IA-32 mode on the IA-64
    architecture.

Contributors
============

This release was made possible by the contributions of many people.
The maintainers are grateful to everyone who has contributed
changes or bug reports.  These include:

Chen Jingpiao
DJ Delorie
Dmitry V. Levin
Elvira Khabirova
Eugene Syromyatnikov
Gleb Fotengauer-Malinovskiy
Harsha Sharma
Lubomir Rintel
Masatake YAMATO
Nikolay Marchuk
Rolf Eike Beer
Victor Krapivensky
Vitaly Chaykovsky

NEWS for strace version 4.20
============================

* Improvements
  * Implemented decoding of NETLINK_NETFILTER netlink message types and flags.
  * Implemented decoding of SECCOMP_GET_ACTION_AVAIL operation of seccomp
    syscall.
  * Updated lists of ARPHRD_*, BPF_*, ETH_P_*, LOOP_*, MADV_*,
    MEMBARRIER_CMD_*, MFD_*, SECCOMP_*, SO_*, SOL_*, TCP_*, and UFFD_FEATURE_*
    constants.
  * Added decoding of statx syscall on hppa.
  * Updated lists of ioctl commands from Linux 4.14.

* Bug fixes
  * Fixed powerpc personality support on powerpc64.

Contributors
============

This release was made possible by the contributions of many people.
The maintainers are grateful to everyone who has contributed
changes or bug reports.  These include:

Baruch Siach
Dmitry V. Levin
Eugene Syromyatnikov
Gleb Fotengauer-Malinovskiy
JingPiao Chen
Steve McIntyre

NEWS for strace version 4.19
============================

* Changes in behaviour
  * Changed formatting of personality names on tile architecture in order
    to make it in line with other multi-personality architectures.
  * Changed field output order in struct v4l2_requestbuffers to improve in/out
    field formatting.
  * Changed handling of multiple signal= specifications in an injection
    expression: multiple specification now leads to error instead of implicit
    usage the last specification.

* Improvements
  * Enhanced decoding of optlen argument of getsockopt syscall.
  * Enhanced decoding of SO_LINGER option of getsockopt and setsockopt syscalls.
  * Enhanced decoding of SO_PEERCRED option of getsockopt syscall.
  * Enhanced decoding of IP_ADD_MEMBERSHIP, IP_DROP_MEMBERSHIP,
    IPV6_ADD_MEMBERSHIP, IPV6_DROP_MEMBERSHIP, IPV6_JOIN_ANYCAST,
    IPV6_LEAVE_ANYCAST, MCAST_JOIN_GROUP, and MCAST_LEAVE_GROUP options
    of setsockopt syscall.
  * Enhanced decoding of KEYCTL_DH_COMPUTE operation of keyctl syscall
    (KDF parameters decoding).
  * Implemented decoding of KEYCTL_RESTRICT_KEYRING operation of keyctl syscall.
  * Enhanced decoding of UFFDIO_API ioctl command.
  * Enhanced decoding of BPF_PROG_LOAD, BPF_MAP_CREATE, BPF_MAP_LOOKUP_ELEM,
    and BPF_MAP_GET_NEXT_KEY commands of bpf syscall.
  * Implemented decoding of linux socket filter programs specified
    for SO_ATTACH_FILTER and SO_ATTACH_REUSEPORT_CBPF socket options.
  * Implemented decoding of inet_diag_req_v2, inet_diag_req_compat,
    packet_diag_msg, and smc_diag_msg netlink attributes of NETLINK_SOCK_DIAG.
  * Implemented NETLINK_SELINUX protocol specific decoding.
  * Implemented decoding of netlink message ack flags.
  * Implemented decoding of nlmsgerr netlink attributes.
  * Implemented basic protocol specific decoding of NETLINK_CRYPTO.
  * Implemented decoding of crypto_user_alg netlink attributes
    of NETLINK_CRYPTO.
  * Implemented basic protocol specific decoding of addr, addrlabel, dcb, link,
    mdb, neigh, neightbl, netconf, nsid, route, rule, tc, and tca messages
    of NETLINK_ROUTE.
  * Implemented decoding of NETLINK_KOBJECT_UEVENT messages.
  * Improved handling of unexpected tracees (the ones that cloned with
    CLONE_PARENT/CLONE_PTRACE or called PTRACE_TRACEME on themselves): they
    are now PTRACE_DETACH'ed instead of PTRACE_CONT'ed.
  * Updated lists of BPF_*, KEY_*, RWF_*, SCM_*, SO_*, and *_MAGIC constants.
  * Added decoding of arch_prctl syscall on x86.
  * Added decoding of seccomp, bpf, userfaultfd, membarrier, mlock2,
    copy_file_range, preadv2, pwritev2, and statx on alpha.
  * Added decoding of statx syscall on microblaze.
  * Added decoding of s390_guarded_storage syscall on s390.
  * Updated lists of ioctl commands from Linux 4.13.
  * Enhanced manual page.

* Bug fixes
  * Fixed printing of group_req structure on non-native personalities.
  * Fixed output formatting of blkpg_ioctl_arg, dm_name_list, and iocb
    structures.
  * Fixed formatting of nul-terminated strings which have kernel-imposed size
    limit.
  * Fixed printing of paths that hit PATM_MAX limit in order to match kernel's
    behaviour.
  * Fixed build warnings on Android mips64.
  * Fixed unused function "is_negated_errno" build warning when built
    with clang.
  * Fixed syscall number and arguments retrieval behaviour on sparc64 and
    mips o32 after prctl(PR_SET_DUMPABLE, 0) makes PTRACE_PEEKTEXT impossible
    to use if Linux kernel has commit v4.10-rc1~114^2~2.
  * Fixed path tracing for execveat, symlink, symlinkat, inotify_add_watch,
    and inotify_init syscalls.
  * Fixed personality switch printing on sparc64 and risc-v.

Contributors
============

This release was made possible by the contributions of many people.
The maintainers are grateful to everyone who has contributed
changes or bug reports.  These include:

Anatoly Pugachev
Dmitry V. Levin
Edgar Kaziakhmedov
Eugene Syromyatnikov
Fabien Siron
Gleb Fotengauer-Malinovskiy
JingPiao Chen
Lazar Trsic
Nikolay Marchuk
Victor Krapivensky

NEWS for strace version 4.18
============================

* Improvements
  * Implemented decoding of SCM_TIMESTAMP* control messages.
  * Implemented decoding of netlink NLMSG_DONE messages.
  * Implemented decoding of netlink generic nlmsg_type and nlmsg_flags.
  * Implemented decoding of NETLINK_AUDIT, NETLINK_NETFILTER, NETLINK_ROUTE,
    NETLINK_SELINUX, NETLINK_SOCK_DIAG, and NETLINK_XFRM message types.
  * Implemented decoding of NETLINK_GENERIC protocol families.
  * Implemented basic protocol specific decoding of AF_INET, AF_INET6,
    AF_NETLINK, AF_PACKET, AF_SMC, and AF_UNIX messages of NETLINK_SOCK_DIAG.
  * Implemented basic decoding of netlink attributes.
  * Implemented basic protocol specific decoding of AF_INET, AF_NETLINK,
    AF_PACKET, AF_SMC, and AF_UNIX netlink attributes of NETLINK_SOCK_DIAG.
  * Implemented decoding of inet_diag_msg, netlink_diag_msg, and unix_diag_msg
    netlink attributes of NETLINK_SOCK_DIAG.
  * Updated lists of ARPHRD_*, KEYCTL_*, NDIAG_SHOW_*, RTM_*, SCM_*, SCTP_*,
    SO_*, V4L2_*, and prctl ARCH_* constants.
  * Updated lists of ioctl commands from Linux 4.12.

* Bug fixes
  * In interactive mode (-I2), those signals that were blocked at startup
    will remain blocked for the whole period of strace execution.
  * strace no longer resets SIGCHLD handler in tracees to the default action.
  * When traced command is terminated by a blocked signal, strace unblocks
    that signal to ensure its own termination with the same signal.
  * Fixed corner cases in decoding of old sigaction syscall.
  * Fixed build with old kernel headers on mips.
  * Fixed build on aarch64 and tile with glibc >= 2.26.
  * Fixed build on arc and nios2.

Contributors
============

This release was made possible by the contributions of many people.
The maintainers are grateful to everyone who has contributed
changes or bug reports.  These include:

Andreas Schwab
David Robins
Dmitry V. Levin
Eugene Syromyatnikov
Eugeniy Paltsev
Fabien Siron
Gleb Fotengauer-Malinovskiy
JingPiao Chen
Khem Raj
Masatake YAMATO
Miroslav Lichvar
Romain Naour
Victor Krapivensky

NEWS for strace version 4.17
============================

* Changes in command line syntax
  * Syscall classes specified in -e trace= option now have % prefix (like
    -e trace=%process).  Old style class names without leading % are still
    supported, but considered deprecated now.

* Improvements
  * Optimized syscall filtering.
  * Improved representation of timestamps.
  * Enhanced decoding of sched_setattr syscall.
  * Added -e trace=%stat option for tracing variants of stat syscall.
  * Added -e trace=%lstat option for tracing variants of lstat syscall.
  * Added -e trace=%fstat option for tracing variants of fstat and fstatat
    syscalls.
  * Added -e trace=%%stat option for tracing syscalls used for querying file
    status information (stat, lstat, fstat, fstatat, statx, and their
    variations).
  * Added -e trace=%statfs option for tracing statfs, statfs64 and statvfs
    syscalls.
  * Added -e trace=%fstatfs option for tracing fstatfs, fstatfs64 and fstatvfs
    syscalls.
  * Added -e trace=%%statfs option for tracing syscalls used for querying file
    system statistics information (statfs-like, fstatfs-like and ustat).
  * Added -e trace=/regex option for filtering syscalls using regular
    expressions.
  * Added support for prepending of question mark before syscall qualification
    in -e trace expressions in order to suppress error in case no syscalls
    matched the provided qualification.
  * Implemented decoding of signal mask in rt_sigreturn syscall on alpha, arc,
    arm, avr32, bfin, cris, hppa, m68k, metag, microblaze, mips, nios2, or1k,
    powerpc, powerpc64, riscv, sh, sh64, sparc, sparc64, tile, x86, and xtensa
    architectures.
  * Implemented decoding of statx syscall.
  * Implemented decoding of NS_* ioctl commands.
  * Implemented decoding of the remaining V4L2_BUF_TYPE_* types.
  * Implemented decoding of VIDIOC_[SG]_TUNER ioctl commands.
  * Implemented decoding of NLMSG_ERROR netlink messages.
  * Improved decoding of BPF_PROG_ATTACH command of bpf syscall.
  * Improved decoding of misplaced parts in DM_* ioctl commands.
  * Updated lists of ioctl commands from Linux 4.11.

* Bug fixes
  * Fixed decoding of flags argument of preadv2 and pwritev2 syscalls on x32.
  * Fixed the number of arguments and tracing flags of alpha specific syscalls.
  * Fixed decoding of old sigsuspend syscall on alpha, cris, mips, powerpc,
    powerpc64, sh, sh64, sparc, and sparc64.
  * Fixed decoding of sgetmask and ssetmask syscalls on 64-bit architectures.
  * Fixed decoding of netlink messages received within struct msghdr.
  * Worked around a bug in miscompiled aarch64 kernels leading to the 3rd
    argument of sched_getattr syscall being not quite 32-bit.
  * Fixed corner cases of printing inaccessible times argument of utimes
    and futimesat syscalls.

Contributors
============

This release was made possible by the contributions of many people.
The maintainers are grateful to everyone who has contributed
changes or bug reports.  These include:

Abhishek Tiwari <erabhishektiwarics@gmail.com>
Andreas Schwab <schwab@suse.de>
Damien Profeta <damien.profeta@amadeus.com>
Dmitry V. Levin <ldv@altlinux.org>
Edgar Kaziahmedov <edos@linux.com>
Elvira Khabirova <lineprinter0@gmail.com>
Eugene Syromyatnikov <evgsyr@gmail.com>
Gleb Fotengauer-Malinovskiy <glebfm@altlinux.org>
JingPiao Chen <chenjingpiao@gmail.com>
Md Haris Iqbal <haris.phnx@gmail.com>
Nikolay Marchuk <marchuk.nikolay.a@gmail.com>
Quentin Monnet <quentin.monnet@6wind.com>
Rishi Bhatt <bhatt.rishi062@gmail.com>
Sandhya Bankar <bankarsandhya512@gmail.com>
Victor Krapivensky <krapivenskiy.va@phystech.edu>

NEWS for strace version 4.16
============================

* Improvements
  * Implemented syscall return value injection (-e inject=SET:retval= option).
  * Implemented signal injection (-e inject=SET:signal= option).
  * Implemented decoding of SUID_DUMP_* constants in PR_[GS]ET_DUMPABLE.
  * Implemented decoding of all SG_* ioctl commands.
  * Implemented decoding of ustat syscall.
  * Implemented decoding of BPF_OBJ_PIN, BPF_OBJ_GET, BPF_PROG_ATTACH,
    and BPF_PROG_DETACH commands of bpf syscall.
  * Enhanced decoding of sg_io_hdr and sg_io_v4 structures.
  * Enhanced decoding of get_robust_list, getrandom, io_submit, set_robust_list
    syscalls.
  * Enhanced decoding of entities of kernel long type on x32 and mips n32 ABIs.
  * Updated lists of IP_*, IPV6_*, and LOOP_* constants.
  * Updated lists of ioctl commands from Linux 4.10.
  * Added decoding of recently added syscalls on avr32, microblaze, ppc,
    and ppc64.

* Bug fixes
  * Fixed pathmatch of oldselect syscall on 64-bit architectures.
  * Fixed decoding of mmap2 syscall on s390 when arguments are not available.
  * Fixed decoding of kexec_file_load, mprotect, pkey_mprotect, prctl, preadv*,
    and pwritev* syscalls on x32.
  * Fixed printing of string arguments of getxattr and setxattr syscalls
    when -s option is used to limit the printed string size.
  * Fixed decoding of ifconf, ifreq, and loop_info structures on non-native
    personalities.
  * Fixed decoding of SG_* and LOOP_* ioctl commands.
  * Fixed build on mips with musl libc.
  * Fixed cross-building of ioctlsort.
  * Applied minor formatting fixes to the manual page.

Contributors
============

This release was made possible by the contributions of many people.
The maintainers are grateful to everyone who has contributed
changes or bug reports.  These include:

Alexey Neyman
Andre McCurdy
Dmitry V. Levin
Elvira Khabirova
Eugene Syromyatnikov
Gabriel Laskar
Gleb Fotengauer-Malinovskiy
Jacob Goense
James Cowgill
JingPiao Chen
Joakim Bech
Quentin Monnet
Seraphime Kirkovski
Марк Коренберг