1Noteworthy changes in release 4.21 (2018-02-13)
2===============================================
3
4* Changes in behaviour
5  * Warning is now issued when -F option is used.
6  * Warning is now issued when a tracee with unsupported personality
7    is attached.
8  * Unknown syscall numbers are now printed in hexadecimal form.
9
10* Improvements
11  * Implemented decoding of netlink descriptor attributes as file descriptors.
12  * Implemented decoding of hugetlb page size selection flags.
13  * Implemented decoding of BPF_PROG_TEST_RUN, BPF_PROG_GET_NEXT_ID,
14    BPF_MAP_GET_NEXT_ID, BPF_PROG_GET_FD_BY_ID, BPF_MAP_GET_FD_BY_ID,
15    and BPF_OBJ_GET_INFO_BY_FD commands of bpf syscall.
16  * Enhanced decoding of get_thread_area, memfd_create, modify_ldt,
17    perf_event_open, reboot, s390_guarded_storage, s390_pcio_mmio_read,
18    s390_pci_mmio_write, s390_runtime_instr, s390_sthyi, set_thread_area,
19    and shmget syscalls.
20  * Implemented decoding of KVM_* and DM_LIST_DEVICES ioctl commands.
21  * Implemented decoding of riscv_flush_icache syscall.
22  * Enhanced decoding of getsockopt and setsockopt syscalls for SOL_NETLINK
23    level.
24  * Enhanced decoding of BPF_MAP_CREATE command of bpf syscall.
25  * Print values returned by mq_open syscall and first arguments
26    of mq_getsetattr, mq_notify, mq_timedreceive, and mq_timedsend syscalls
27    as file descriptors.
28  * Added decoding of get_tls syscall on arm.
29  * Added -e trace=%pure option for tracing system calls with no arguments that
30    never fail.
31  * Updated lists of IPV6_*, MAP_*, MEMBARRIER_CMD_*, MSG_*, NT_*, PKEY_*,
32    SHM_*, and TCP_* constants.
33  * Added manual page for the strace-log-merge command.
34  * Updated lists of ioctl commands from Linux 4.15.
35  * Implemented biarch support for s390x.
36  * Implemented an optional support for symbol demangling in strace -k output
37    (activated by --with-libiberty configure option).
38  * Information about availability of demangling and reliable personality
39    decoding (on architectures with multiple personalities) is now available
40    in strace -V output.
41  * Added decoding of pkey_alloc, pkey_free, and pkey_mprotect syscalls on
42    powerpc and powerpc64.
43  * Enhanced manual page.
44
45* Bug fixes
46  * Fixed multi-personality support in cross builds.
47  * Added mq_getsetattr, mq_notify, mq_open, mq_timedreceive, and mq_timedsend
48    syscalls to %desc tracing set.
49  * Fixed path tracing support for mmap syscalls with indirect arguments and
50    for old select syscall.
51  * Fixed decoding of arm-specific (__ARM_NR_*) syscalls.
52  * Fixed open mode flags decoding.
53  * Fixed corner cases in handling of strace -ff -ttt logs by strace-log-merge.
54  * Error counts that exceed one billion are now printed correctly in call
55    summary output.
56  * Fixed call summary header for x32 personality.
57  * Changes of tracee personalities are reported more reliably.
58  * Fixed the case when strace attaches to a tracee being inside exec and its
59    first syscall stop is syscall-exit-stop instead of syscall-enter-stop,
60    which messed up all the syscall state tracking.
61  * Fixed printing of higher 32 bits of the return value for x32 personality.
62
63* Portability
64  * A C compiler that supports "for" loop initial declarations is now required.
65  * Inability to configure multiple personality support on architectures where
66    multiple personalities are supported leads to configuration failure during
67    build now.  Use --enable-mpers=check to revert to the old behaviour.
68  * Build-time requirement for the mpers support has been lowered from gawk 4
69    to gawk 3.
70  * Removed incomplete and non-functional support for the CRIS architecture.
71  * Removed incomplete and unused support for IA-32 mode on the IA-64
72    architecture.
73
74Noteworthy changes in release 4.20 (2017-11-13)
75===============================================
76
77* Improvements
78  * Implemented decoding of NETLINK_NETFILTER netlink message types and flags.
79  * Implemented decoding of SECCOMP_GET_ACTION_AVAIL operation of seccomp
80    syscall.
81  * Updated lists of ARPHRD_*, BPF_*, ETH_P_*, LOOP_*, MADV_*,
82    MEMBARRIER_CMD_*, MFD_*, SECCOMP_*, SO_*, SOL_*, TCP_*, and UFFD_FEATURE_*
83    constants.
84  * Added decoding of statx syscall on hppa.
85  * Updated lists of ioctl commands from Linux 4.14.
86
87* Bug fixes
88  * Fixed powerpc personality support on powerpc64.
89
90Noteworthy changes in release 4.19 (2017-09-05)
91===============================================
92
93* Changes in behaviour
94  * Changed formatting of personality names on tile architecture in order
95    to make it in line with other multi-personality architectures.
96  * Changed field output order in struct v4l2_requestbuffers to improve in/out
97    field formatting.
98  * Changed handling of multiple signal= specifications in an injection
99    expression: multiple specification now leads to error instead of implicit
100    usage the last specification.
101
102* Improvements
103  * Enhanced decoding of optlen argument of getsockopt syscall.
104  * Enhanced decoding of SO_LINGER option of getsockopt and setsockopt syscalls.
105  * Enhanced decoding of SO_PEERCRED option of getsockopt syscall.
106  * Enhanced decoding of IP_ADD_MEMBERSHIP, IP_DROP_MEMBERSHIP,
107    IPV6_ADD_MEMBERSHIP, IPV6_DROP_MEMBERSHIP, IPV6_JOIN_ANYCAST,
108    IPV6_LEAVE_ANYCAST, MCAST_JOIN_GROUP, and MCAST_LEAVE_GROUP options
109    of setsockopt syscall.
110  * Enhanced decoding of KEYCTL_DH_COMPUTE operation of keyctl syscall
111    (KDF parameters decoding).
112  * Implemented decoding of KEYCTL_RESTRICT_KEYRING operation of keyctl syscall.
113  * Enhanced decoding of UFFDIO_API ioctl command.
114  * Enhanced decoding of BPF_PROG_LOAD, BPF_MAP_CREATE, BPF_MAP_LOOKUP_ELEM,
115    and BPF_MAP_GET_NEXT_KEY commands of bpf syscall.
116  * Implemented decoding of linux socket filter programs specified
117    for SO_ATTACH_FILTER and SO_ATTACH_REUSEPORT_CBPF socket options.
118  * Implemented decoding of inet_diag_req_v2, inet_diag_req_compat,
119    packet_diag_msg, and smc_diag_msg netlink attributes of NETLINK_SOCK_DIAG.
120  * Implemented NETLINK_SELINUX protocol specific decoding.
121  * Implemented decoding of netlink message ack flags.
122  * Implemented decoding of nlmsgerr netlink attributes.
123  * Implemented basic protocol specific decoding of NETLINK_CRYPTO.
124  * Implemented decoding of crypto_user_alg netlink attributes
125    of NETLINK_CRYPTO.
126  * Implemented basic protocol specific decoding of addr, addrlabel, dcb, link,
127    mdb, neigh, neightbl, netconf, nsid, route, rule, tc, and tca messages
128    of NETLINK_ROUTE.
129  * Implemented decoding of NETLINK_KOBJECT_UEVENT messages.
130  * Improved handling of unexpected tracees (the ones that cloned with
131    CLONE_PARENT/CLONE_PTRACE or called PTRACE_TRACEME on themselves): they
132    are now PTRACE_DETACH'ed instead of PTRACE_CONT'ed.
133  * Updated lists of BPF_*, KEY_*, RWF_*, SCM_*, SO_*, and *_MAGIC constants.
134  * Added decoding of arch_prctl syscall on x86.
135  * Added decoding of seccomp, bpf, userfaultfd, membarrier, mlock2,
136    copy_file_range, preadv2, pwritev2, and statx on alpha.
137  * Added decoding of statx syscall on microblaze.
138  * Added decoding of s390_guarded_storage syscall on s390.
139  * Updated lists of ioctl commands from Linux 4.13.
140  * Enhanced manual page.
141
142* Bug fixes
143  * Fixed printing of group_req structure on non-native personalities.
144  * Fixed output formatting of blkpg_ioctl_arg, dm_name_list, and iocb
145    structures.
146  * Fixed formatting of nul-terminated strings which have kernel-imposed size
147    limit.
148  * Fixed printing of paths that hit PATM_MAX limit in order to match kernel's
149    behaviour.
150  * Fixed build warnings on Android mips64.
151  * Fixed unused function "is_negated_errno" build warning when built
152    with clang.
153  * Fixed syscall number and arguments retrieval behaviour on sparc64 and
154    mips o32 after prctl(PR_SET_DUMPABLE, 0) makes PTRACE_PEEKTEXT impossible
155    to use if Linux kernel has commit v4.10-rc1~114^2~2.
156  * Fixed path tracing for execveat, symlink, symlinkat, inotify_add_watch,
157    and inotify_init syscalls.
158  * Fixed personality switch printing on sparc64 and risc-v.
159
160Noteworthy changes in release 4.18 (2017-07-05)
161===============================================
162
163* Improvements
164  * Implemented decoding of SCM_TIMESTAMP* control messages.
165  * Implemented decoding of netlink NLMSG_DONE messages.
166  * Implemented decoding of netlink generic nlmsg_type and nlmsg_flags.
167  * Implemented decoding of NETLINK_AUDIT, NETLINK_NETFILTER, NETLINK_ROUTE,
168    NETLINK_SELINUX, NETLINK_SOCK_DIAG, and NETLINK_XFRM message types.
169  * Implemented decoding of NETLINK_GENERIC protocol families.
170  * Implemented basic protocol specific decoding of AF_INET, AF_INET6,
171    AF_NETLINK, AF_PACKET, AF_SMC, and AF_UNIX messages of NETLINK_SOCK_DIAG.
172  * Implemented basic decoding of netlink attributes.
173  * Implemented basic protocol specific decoding of AF_INET, AF_NETLINK,
174    AF_PACKET, AF_SMC, and AF_UNIX netlink attributes of NETLINK_SOCK_DIAG.
175  * Implemented decoding of inet_diag_msg, netlink_diag_msg, and unix_diag_msg
176    netlink attributes of NETLINK_SOCK_DIAG.
177  * Updated lists of ARPHRD_*, KEYCTL_*, NDIAG_SHOW_*, RTM_*, SCM_*, SCTP_*,
178    SO_*, V4L2_*, and prctl ARCH_* constants.
179  * Updated lists of ioctl commands from Linux 4.12.
180
181* Bug fixes
182  * In interactive mode (-I2), those signals that were blocked at startup
183    will remain blocked for the whole period of strace execution.
184  * strace no longer resets SIGCHLD handler in tracees to the default action.
185  * When traced command is terminated by a blocked signal, strace unblocks
186    that signal to ensure its own termination with the same signal.
187  * Fixed corner cases in decoding of old sigaction syscall.
188  * Fixed build with old kernel headers on mips.
189  * Fixed build on aarch64 and tile with glibc >= 2.26.
190  * Fixed build on arc and nios2.
191
192Noteworthy changes in release 4.17 (2017-05-24)
193===============================================
194
195* Changes in command line syntax
196  * Syscall classes specified in -e trace= option now have % prefix (like
197    -e trace=%process).  Old style class names without leading % are still
198    supported, but considered deprecated now.
199
200* Improvements
201  * Optimized syscall filtering.
202  * Improved representation of timestamps.
203  * Enhanced decoding of sched_setattr syscall.
204  * Added -e trace=%stat option for tracing variants of stat syscall.
205  * Added -e trace=%lstat option for tracing variants of lstat syscall.
206  * Added -e trace=%fstat option for tracing variants of fstat and fstatat
207    syscalls.
208  * Added -e trace=%%stat option for tracing syscalls used for querying file
209    status information (stat, lstat, fstat, fstatat, statx, and their
210    variations).
211  * Added -e trace=%statfs option for tracing statfs, statfs64 and statvfs
212    syscalls.
213  * Added -e trace=%fstatfs option for tracing fstatfs, fstatfs64 and fstatvfs
214    syscalls.
215  * Added -e trace=%%statfs option for tracing syscalls used for querying file
216    system statistics information (statfs-like, fstatfs-like and ustat).
217  * Added -e trace=/regex option for filtering syscalls using regular
218    expressions.
219  * Added support for prepending of question mark before syscall qualification
220    in -e trace expressions in order to suppress error in case no syscalls
221    matched the provided qualification.
222  * Implemented decoding of signal mask in rt_sigreturn syscall on alpha, arc,
223    arm, avr32, bfin, cris, hppa, m68k, metag, microblaze, mips, nios2, or1k,
224    powerpc, powerpc64, riscv, sh, sh64, sparc, sparc64, tile, x86, and xtensa
225    architectures.
226  * Implemented decoding of statx syscall.
227  * Implemented decoding of NS_* ioctl commands.
228  * Implemented decoding of the remaining V4L2_BUF_TYPE_* types.
229  * Implemented decoding of VIDIOC_[SG]_TUNER ioctl commands.
230  * Implemented decoding of NLMSG_ERROR netlink messages.
231  * Improved decoding of BPF_PROG_ATTACH command of bpf syscall.
232  * Improved decoding of misplaced parts in DM_* ioctl commands.
233  * Updated lists of ioctl commands from Linux 4.11.
234
235* Bug fixes
236  * Fixed decoding of flags argument of preadv2 and pwritev2 syscalls on x32.
237  * Fixed the number of arguments and tracing flags of alpha specific syscalls.
238  * Fixed decoding of old sigsuspend syscall on alpha, cris, mips, powerpc,
239    powerpc64, sh, sh64, sparc, and sparc64.
240  * Fixed decoding of sgetmask and ssetmask syscalls on 64-bit architectures.
241  * Fixed decoding of netlink messages received within struct msghdr.
242  * Worked around a bug in miscompiled aarch64 kernels leading to the 3rd
243    argument of sched_getattr syscall being not quite 32-bit.
244  * Fixed corner cases of printing inaccessible times argument of utimes
245    and futimesat syscalls.
246
247Noteworthy changes in release 4.16 (2017-02-14)
248===============================================
249
250* Improvements
251  * Implemented syscall return value injection (-e inject=SET:retval= option).
252  * Implemented signal injection (-e inject=SET:signal= option).
253  * Implemented decoding of SUID_DUMP_* constants in PR_[GS]ET_DUMPABLE.
254  * Implemented decoding of all SG_* ioctl commands.
255  * Implemented decoding of ustat syscall.
256  * Implemented decoding of BPF_OBJ_PIN, BPF_OBJ_GET, BPF_PROG_ATTACH,
257    and BPF_PROG_DETACH commands of bpf syscall.
258  * Enhanced decoding of sg_io_hdr and sg_io_v4 structures.
259  * Enhanced decoding of get_robust_list, getrandom, io_submit, set_robust_list
260    syscalls.
261  * Enhanced decoding of entities of kernel long type on x32 and mips n32 ABIs.
262  * Updated lists of IP_*, IPV6_*, and LOOP_* constants.
263  * Updated lists of ioctl commands from Linux 4.10.
264  * Added decoding of recently added syscalls on avr32, microblaze, ppc,
265    and ppc64.
266
267* Bug fixes
268  * Fixed pathmatch of oldselect syscall on 64-bit architectures.
269  * Fixed decoding of mmap2 syscall on s390 when arguments are not available.
270  * Fixed decoding of kexec_file_load, mprotect, pkey_mprotect, prctl, preadv*,
271    and pwritev* syscalls on x32.
272  * Fixed printing of string arguments of getxattr and setxattr syscalls
273    when -s option is used to limit the printed string size.
274  * Fixed decoding of ifconf, ifreq, and loop_info structures on non-native
275    personalities.
276  * Fixed decoding of SG_* and LOOP_* ioctl commands.
277  * Fixed build on mips with musl libc.
278  * Fixed cross-building of ioctlsort.
279  * Applied minor formatting fixes to the manual page.
280
281Noteworthy changes in release 4.15 (2016-12-14)
282===============================================
283
284* Changes in behavior
285  * Time stamps are now printed according to ISO 8601.
286  * Changed output format of val3 parameter of futex FUTEX_WAKE_OP operation.
287  * The last argument of mincore, sched_getaffinity, and sched_setaffinity
288    syscalls is now formatted as an array.
289
290* Improvements
291  * Implemented syscall fault injection (-e fault=... option).
292  * Implemented decoding of DM_* ioctl commands.
293  * Implemented decoding of attr parameter of perf_event_open syscall.
294  * Implemented decoding of pkey_alloc, pkey_free, and pkey_mprotect syscalls.
295  * Implemented dumping of mq_timedsend and mq_timedreceive syscalls.
296  * Implemented decoding of PR_SET_FP_MODE and PR_GET_FP_MODE operations
297    of prctl syscall.
298  * Implemented PTRACE_GETREGS API support on m68k.
299  * Updated lists of ARCH_*, BPF_*, BTRFS_*, FALLOC_*, MS_*, *_MAGIC,
300    and V4L2_* constants.
301  * Updated lists of ioctl commands from Linux 4.9.
302  * Added decoding of recently added syscalls on arc, x32, and xtensa.
303  * Enhanced manual page.
304
305* Bug fixes
306  * Fixed corner cases in decoding of exit, exit_group, futimesat, getgroups,
307    getresuid, init_module, inotify_init1, kcmp, kexec_load, lookup_dcookie,
308    mq_getsetattr, mq_notify, mq_open, mq_timedreceive, mq_timedsend,
309    name_to_handle_at, prctl, process_vm_readv, process_vm_writev, setfsuid,
310    setgroups, setns, unshare, and utimes syscalls.
311  * Fixed handling of verbose flag in printing of controls array
312    of struct v4l2_ext_controls.
313  * Fixed omission of field names in the output of capability, sigaction,
314    sigevent, statfs, timespec, timeval, and utimbuf structures.
315  * Fixed printing of unknown syscalls in siginfo structure.
316  * Fixed decoding of ioctl constants on m68k.
317  * Fixed cris architecture support.
318  * Fixed cross build when host compiler does not support the same
319    set of warning flags as the cross compiler.
320  * Fixed build on SLE10 and SLE11.
321
322Noteworthy changes in release 4.14 (2016-10-04)
323===============================================
324
325* Changes in behavior
326  * When using -p option without a command and no processes has been attached,
327    strace exits with exit status 1.
328
329* Improvements
330  * Added printing of the mode argument of open and openat syscalls
331    when O_TMPFILE flag is set.  (Addresses Fedora bug #1377846).
332  * Enhanced -e abbrev=set, -e raw=set, and -e verbose=set.
333  * Enhanced decoding of futex, keyctl, quotactl, timerfd_settime,
334    and aio family syscalls.
335  * Implemented fetching of the 7th subcall argument on mips o32.
336  * Updated lists of BPF_*, ETH_P_*, KEXEC_ARCH_*, SCTP_*, TCP_*, and *_MAGIC
337    constants.
338  * Updated lists of ioctl commands from Linux 4.8.
339  * Added decoding of new syscalls on sh and sh64.
340  * Added RISC-V architecture support.
341
342* Bug fixes
343  * Marked io_setup and io_destroy as memory mapping related syscalls.
344  * Fixed leakage of placeholder descriptors to tracees.
345  * Fixed printing of mode_t, umode_t, and umask types.
346  * Fixed decoding of iovec arrays without a limit on total data size.
347  * Fixed decoding of fadvise64, fallocate, futex, keyctl, quotactl, readahead,
348    and ipc family syscalls.
349  * Fixed decoding of invalid syscalls mapped to indirect subcalls.
350  * Fixed decoding of struct btrfs_ioctl_vol_args_v2 on non-native
351    personalities.
352  * Fixed decoding of PTRACE_DETACH on sparc and sparc64.
353  * Fixed decoding of struct stat64 on sparc64.
354  * Fixed decoding of uid and gid-related syscalls on sparc64.
355  * Fixed decoding of the forth argument of semctl syscall on sparc64.
356  * Fixed values of tty ioctl constants on sparc64.
357  * Fixed sparc personality support on sparc64.
358
359Noteworthy changes in release 4.13 (2016-07-26)
360===============================================
361
362* Improvements
363  * Implemented a general netlink socket parser.
364  * Enhanced decoding of socket addresses.
365  * Enhanced decoding of cmsghdr, msghdr, and mmsghdr structures.
366  * Enhanced decoding of accept, accept4, bind, getpeername, getsockname,
367    ipc, recvfrom, recvmsg, recvmmsg, sendto, sendmmsg, and socketcall syscalls.
368  * Updated lists of AF_*, BPF_MAP_TYPE_*, KEY_*, KEYCTL_*, RWF_*, SS_*,
369    and *_MAGIC constants.
370  * Updated lists of ioctl commands from Linux 4.7.
371
372* Bug fixes
373  * Fixed decoding of pid_t argument of prlimit64 syscall.
374  * Fixed sign extension issues in the parser of struct rusage.
375  * Fixed race condition in decoding of timeout argument of recvmmsg and
376    rt_sigtimedwait syscalls.
377  * Fixed build with fresh linux kernel headers.
378
379Noteworthy changes in release 4.12 (2016-05-31)
380===============================================
381
382* Improvements
383  * Implemented simultaneous use of -p option and tracing of a command.
384    (addresses Debian bug #549942).
385  * Implemented caching of netlink conversations to reduce amount of time
386    spent in decoding socket details in -yy mode.
387  * Implemented -yy mode decoding of protocol:portid pairs associated with
388    netlink socket descriptors.
389  * Implemented decoding of copy_file_range, preadv2, and pwritev2 syscalls.
390  * Implemented dumping of preadv, preadv2, pwritev, pwritev2, and vmsplice
391    syscalls.
392  * Implemented decoding of BTRFS_* and UFFDIO_* ioctl commands.
393  * Enhanced decoding of BLK*, EVIOC*, RTC_*, and VIDIOC_* ioctl commands.
394  * Enhanced decoding of fstatfs, fstatfs64, get_mempolicy, getdents,
395    getdents64, getgroups, getpriority, kill, mbind, migrate_pages, mknod,
396    mknodat, personality, poll, ppoll, quotactl, rt_sigpending,
397    rt_sigqueueinfo, rt_sigtimedwait, rt_tgsigqueueinfo, sched_getaffinity,
398    sched_setaffinity, seccomp, set_mempolicy, setgroups, setpriority, statfs,
399    statfs64, tgkill, waitid, and xattr family syscalls.
400  * Enhanced decoding of getxpid, getxuid, and getxgid syscalls on alpha.
401  * Enhanced decoding of pipe syscall on alpha, ia64, mips, sh, and sparc.
402  * Added decoding of bind, listen, and setsockopt direct syscalls on sparc.
403  * Added decoding of osf_statfs64 and osf_fstatfs64 syscalls on alpha.
404  * Added decoding of fadvise64 and fadvise64_64 on s390.
405  * Updated lists of AF_*, BPF_MAP_TYPE_*, CLONE_*, EPOLL*, IPV6_*, MADV_*,
406    MSG_*, PTRACE_*, SEGV_*, SO_*, SOL_*, *_MAGIC, and quotactl constants.
407  * Updated lists of ioctl commands from Linux 4.6.
408
409* Bug fixes
410  * Fixed build on arc, metag, nios2, or1k, and tile architectures.
411  * Fixed decoding of 32-bit times syscall return value on 64-bit architectures.
412  * Fixed decoding of mlock2 syscall on sparc.
413  * Fixed decoding of osf_shmat syscall on alpha.
414  * Fixed decoding of syscalls unknown to the kernel on s390/s390x.
415    (addresses Debian bug #485979 and Fedora bug #1298294).
416  * Fixed decoding of preadv syscall in case of short read.
417  * Fixed decoding and dumping of readv syscall in case of short read.
418  * Fixed dumping of recvmsg and recvmmsg syscalls in case of short read.
419  * Fixed decoding of mincore syscall's last argument.
420  * Fixed remaining errors in mapping between syscall numbers and numbers
421    of syscall arguments.
422  * Applied various fixes to strace-graph script.
423
424Noteworthy changes in release 4.11 (2015-12-21)
425===============================================
426
427* Changes in behavior
428  * Some syscalls have different names depending on architecture and
429    personality.  In these cases, syscall filtering and printing now
430    consistently uses the names that match corresponding __NR_* kernel
431    macros of the tracee's architecture and personality.
432  * Added strace prefix to all diagnostic messages.
433
434* Improvements
435  * Enhanced and extended test suite.
436  * Implemented reliable tracing of processes whose personality differs
437    from the personality of strace, fixed decoding of 32-bit personality
438    syscalls on 64-bit architectures.
439  * When some data referenced by syscall arguments is irrelevant or cannot
440    be read from tracee's memory, strace now prints its address consistently.
441  * When a syscall is restarted using restart_syscall mechanism, strace now
442    shows the syscall name on architectures that expose this information.
443  * Print values returned by epoll_create1, eventfd, eventfd2, fanotify_init,
444    inotify_init1, perf_event_open, pipe, pipe2, signalfd, signalfd4, socket,
445    socketpair, timerfd, and timerfd_create syscalls, as well as F_DUPFD and
446    F_DUPFD_CLOEXEC fcntl commands, as file descriptors.
447  * Optimized decoding of indirect socket syscalls.
448  * Implemented decoding of nanoseconds along with seconds in stat family
449    syscalls (addresses Fedora bug #1251176).
450  * Implemented decoding of struct statfs.f_flags in statfs syscall.
451  * Implemented decoding of siginfo_t.si_syscall and siginfo_t.si_arch
452    in SIGSYS signal.
453  * Implemented decoding of indirect syscall on mips o32.
454  * Implemented decoding of IPPROTO_IP control messages.
455  * Implemented decoding of setsockopt syscall multicast arguments.
456  * Enhanced decoding of struct sigevent.
457  * Enhanced decoding of block, loop, mtd, ptp, rtc, SG_IO, socket, tty,
458    and v4l2 ioctl syscall arguments.
459  * Enhanced decoding of epoll_create, fcntl, fcntl64, futex, getdents,
460    getdents64, getsockopt, io_*, mount, msgctl, prctl, quotactl, recvfrom,
461    sendfile, setsockopt, and shmctl syscalls.
462  * Implemented decoding of bpf, execveat, ioperm, iopl, kcmp, kexec_file_load,
463    lookup_dcookie, membarrier, memfd_create, mlock2, name_to_handle_at,
464    open_by_handle_at, sched_getattr, sched_setattr, and userfaultfd syscalls.
465  * Updated lists of AF_*, EPOLL_*, FALLOC_FL_*, F_*, INPUT_PROP_*, IPPROTO_*,
466    IPV6_*, IP_*, KEY_*, LOCK_*, MNT_*, MS_*, PACKET_*, PERF_FLAG_*, PF_*,
467    PR_*, PTRACE_O_*, RENAME_*, SCTP_*, SECBIT_*, SO_*, TCP_*, and siginfo_t
468    constants.
469  * Added Nios II architecture support.
470  * Added new syscall entries to match Linux 4.4.
471
472* Bug fixes
473  * Fixed potential short read of strings from tracee's memory.
474  * Fixed -qq option in conjunction with -o option.
475  * Fixed filtering of <unavailable> syscalls.
476  * Fixed decoding of ioctl syscall command on aarch64 and 32-bit architectures
477    with 64-bit aligned structures.
478  * Fixed decoding of eventfd2, epoll_create1, signalfd4, and sync_file_range2
479    syscall flags arguments.
480  * Fixed decoding of 4th argument of clock_nanosleep syscall.
481  * Fixed decoding of getpagesize syscall on m68k.
482  * Fixed decoding of getrandom and seccomp syscalls on aarch64.
483  * Fixed decoding of timezone argument of gettimeofday and settimeofday
484  * syscalls.
485  * Fixed decoding of offset argument of mmap2 syscall on arm, sparc,
486    and sparc64.
487  * Fixed decoding of pipe syscall on alpha and mips.
488  * Fixed decoding of pipe2 syscall on ia64, sh, sparc, and sparc64.
489  * Fixed decoding of signal mask argument of pselect6 syscall on x32.
490  * Fixed decoding of signal mask of rt_sigreturn syscall on aarch64, m68k,
491    and x32.
492  * Fixed decoding of 4th argument of semctl indirect syscall.
493  * Fixed decoding of sa_restorer and sa_mask of sigaction syscall on m68k.
494  * Fixed decoding of statfs64 and fstatfs64 syscalls on arm eabi.
495  * Fixed decoding of struct dirent on x32.
496  * Fixed decoding of times syscall return value on mips n32 and x32.
497  * Fixed decoding of path argument of umount2 syscall
498    (addresses Debian bug #785050).
499  * Worked around a kernel bug in tracing privileged executables.
500  * Fixed various errors in mapping between syscall numbers and associated
501    information like the number of syscall arguments, the name of syscall,
502    and syscall decoder.
503
504Noteworthy changes in release 4.10 (2015-03-06)
505===============================================
506
507* Improvements
508  * Added -yy option to print protocol and address information associated with
509    socket descriptors.
510  * Extended "-e read=set" and "-e write=set" options to cover sendmsg,
511    recvmsg, sendmmsg, and recvmmsg syscalls.
512  * Implemented full 32-bit decoding of ioctl commands
513    (addresses Debian bug #692913 and Fedora bug #902788).
514  * Implemented PTRACE_GETREGS API support on ia64.
515  * Implemented PTRACE_GETREGS API support on mips.
516  * Implemented PTRACE_GETREGSET API support on s390/s390x.
517  * Implemented decoding of getrandom and seccomp syscalls.
518  * Implemented full decoding of 64-bit capability sets.
519  * Implemented decoding of all prctl commands.
520  * Implemented decoding of parametrized ioctl commands.
521  * Implemented decoding of evdev ioctl commands.
522  * Implemented decoding of v4l ioctl commands.
523  * Implemented decoding of SG_IO v4 ioctl commands.
524  * Implemented decoding of FIFREEZE/FITHAW/FITRIM ioctl commands.
525  * Implemented decoding of FALLOC_FL_* fallocate flags.
526  * Implemented decoding of rt_sigreturn signal mask on aarch64,
527    x32, and x86_64.
528  * Enhanced socket decoder to support bluetooth sockets.
529  * Enhanced decoding of unlisted ioctl commands.
530  * Enhanced decoding of getsockopt and setsockopt syscall.
531  * Enhanced decoding of sysinfo syscall.
532  * Enhanced decoding of struct cmsghdr.
533  * Enhanced decoding of wait status.
534  * Enhanced aio support on non-x86 architectures by using external libaio.h.
535  * Added O_TMPFILE to the list of recognized open mode flags.
536  * Updated the list of filesystem type constants that is used in decoding
537    statfs family syscalls.
538  * Updated lists of CAP_*, PR_*, PTRACE_*, SCHED_*, SO_*, SOL_*, SWAP_FLAG_*,
539    and TFD_* constants.
540  * Updated lists of signal constants from Linux 3.19.
541  * Updated lists of errno constants from Linux 3.19.
542  * Updated lists of ioctl commands from Linux 3.9.
543  * Added new syscall entries to match Linux 3.19.
544
545* Bug fixes
546  * Fixed various errors in mapping between syscall numbers and associated
547    information like the number of syscall arguments, the name of syscall,
548    and syscall decoder.
549  * Fixed quoting issues in printing descriptors, filenames, network interface
550    names, struct utsname members, device/volume names of BLK* ioctl commands.
551  * Fixed uid_t/git_t decoding.
552  * Fixed potential out-of-bounds read issues in getdents/getdents64 decoders.
553  * Fixed potential open flags truncation on some architectures.
554  * Fixed decoding of struct ifreq.ifr_name.
555  * Fixed decoding of SIOCSIFNAME ioctl command.
556  * Fixed decoding of RENAME_* renameat2 flags.
557  * Fixed decoding of UTIME_NOW/UTIME_OMIT timeval structures.
558  * Fixed decoding of indirect ipc subcalls on some architectures.
559  * Fixed decoding of fanotify_mark syscall on 32-bit architectures.
560  * Fixed decoding of 32-bit stat structures on 64-bit architectures.
561  * Fixed decoding of 32-bit struct cmsghdr on 64-bit architectures.
562  * Fixed decoding of 32-bit preadv/pwritev offset on 64-bit architectures.
563  * Fixed decoding of sigreturn/rt_sigreturn signal mask on ia64, ppc, ppc64,
564    sparc, sparc64, mips, and s390.
565  * Fixed instruction pointer output (-i option) on architectures that support
566    several personalities.
567  * Fixed behaviour of "-e read=set" and "-e write=set" when read and write
568    sets intersect.
569  * Fixed build on systems where struct sigaction has no sa_restorer member.
570  * Fixed build with uclibc and musl libc.
571
572* Portability
573  * Linux kernel >= 2.5.46 is required.
574    Older versions without a decent PTRACE_SETOPTIONS support will not work.
575  * On mips, linux kernel >= 2.6.15 is required.
576    Older versions without a decent PTRACE_GETREGS support will not work.
577  * On s390 and s390x, linux kernel >= 2.6.27 is required.
578    Older versions without a decent PTRACE_GETREGSET support will not work.
579
580Noteworthy changes in release 4.9 (2014-08-15)
581==============================================
582
583* Changes in behavior
584  * Disabled OABI support on ARM EABI systems by default,
585    added --enable-arm-oabi option to enable it at configure time.
586
587* Improvements
588  * Added experimental -k option to print stack trace after each traced syscall.
589  * Added -w option to produce stats on syscall latency.
590    (addresses Debian bug #457497).
591  * Added ARC architecture support.
592  * Added PTRACE_GETREGS API support on PowerPC.
593  * Enhanced Bionic libc and musl libc support.
594  * Enhanced tracing of x86 personality processes on x86_64 and x32.
595  * Enhanced tracing of ARM personality processes on AArch64.
596  * Enhanced 32/64bit personality detection on PowerPC.
597  * Implemented decoding of add_key, ioprio_get, ioprio_set, kexec_load, keyctl,
598    renameat2, and request_key syscalls.
599  * Robustified decoding of select, pselect, and io_submit syscalls.
600  * Enhanced decoding of delete_module, fanotify_init, fanotify_mark, fcntl,
601    setdomainname, sethostname, setns, and sync_file_range syscalls.
602  * Enhanced decoding of signal bitmasks.
603  * Enhanced decoding of file descriptors.
604  * Enhanced siginfo_t decoding.
605  * Enhanced PF_NETLINK decoding.
606  * Updated CLOCK_* constants
607    (addresses Fedora bug #1088455).
608  * Added new syscall entries to match Linux 3.16.
609
610* Bug fixes
611  * Added shmat and shmdt to the set of memory mapping related syscalls.
612  * Fixed detaching from stopped processes.
613  * Fixed fanotify_mark decoding on 32bit architectures.
614  * Fixed offset decoding in preadv and pwritev syscalls.
615  * Fixed select decoding for glibc in _FORTIFY_SOURCE mode.
616  * Fixed decoding of epoll_ctl syscall with EPOLL_CTL_DEL argument.
617  * Fixed build when <sys/ptrace.h> and <linux/ptrace.h> conflict
618    (addresses Fedora bug #993384).
619  * Miscellaneous corrections in the manual page.
620    (Addresses Debian bug #725987).
621
622Noteworthy changes in release 4.8 (2013-06-03)
623==============================================
624
625* Changes in behavior
626  * In case of normal strace termination, when the trace output is
627    redirected to a pipe, strace now closes it and waits for the pipe
628    process termination before exit.
629
630* Improvements
631  * Implemented tracing using PTRACE_SEIZE API (when available).
632  * Implemented more reliable PTRACE_GETREGSET-based process personality
633    detection on x86-64 and x32 (when available).
634  * Added -e trace=memory option for tracing memory mapping related syscalls.
635  * Documented -b option.
636  * Allowed exit status messages to be suppressed by giving -q option twice.
637  * Added AArch64 architecture support
638    (addresses Debian bug #693074 and Fedora bug #969858).
639  * Added support for OpenRISC 1000, Meta, and Xtensa architectures.
640  * Added tilegx personality support for Tile.
641  * Enhanced support of NOMMU architectures.
642  * Enhanced decoding of getdents, mmap, perf_event_open, ptrace, and
643    quotactl syscalls.
644  * Added new syscall entries to match Linux 3.9.
645  * Regenerated the list of common ioctl names from Linux 3.9.
646  * Updated the list of errno constants.
647  * Updated lists of AF_*, MADV_*, MAP_*, MSG_*, MS_*, PF_*, PR_*,
648    PTRACE_O_*, and TCP_* constants.
649  * Implemented decoding of UBI ioctls.
650  * Removed redundant "*32" ioctl names.
651
652* Bug fixes
653  * Fixed ERESTARTNOINTR leaking to userspace on ancient kernels
654    (addresses Fedora bug #659382).
655  * Fixed kernel release string parsing
656    (addresses Debian bug #702309).
657  * Fixed decoding of *xattr syscalls
658    (addresses Fedora bug #885233).
659  * Fixed handling of files with 64-bit inode numbers by 32-bit strace
660    (addresses Fedora bug #912790).
661  * Fixed tracing forks on SPARC.
662  * Fixed decoding of fadvise64, fallocate, ftruncate64, io_submit, pread,
663    preadv, pwrite, pwritev, readahead, sigaltstack, sync_file_range, sysctl,
664    and truncate64 syscalls.
665  * Fixed categories of multiple syscalls on most of supported architectures.
666  * Fixed decoding of non-native 32-bit personality recv[m]msg syscalls.
667  * Fixed decoding of multiple 32-bit personality syscalls on x32.
668  * Fixed decoding of long long syscall arguments on ARM, MIPS/o32, PowerPC,
669    S390x, and Tile architectures.
670  * Fixed semtimedop decoding on S390x.
671  * Fixed sram_alloc decoding on Blackfin.
672  * Fixed build when process_vm_readv is a stab.
673  * Fixed build with older versions of libaio.h.
674
675Noteworthy changes in release 4.7 (2012-05-02)
676==============================================
677
678* Changes in behavior
679  * strace no longer suspends waitpid until there is a child
680    for waitpid'ing process to collect status from.
681  * strace no longer detaches from a tracee which is supposed
682    to be going to die.
683  * strace now issues a new message: "+++ exited with EXITCODE +++"
684    which shows exact moment strace got exit notification,
685    analogous to existing "+++ killed by SIG +++" message.
686
687* Improvements
688  * Added x32 personality support (x86_64 architecture).
689  * Added -y and -P options to print file descriptor paths and
690    filter by those paths.
691  * Added -I option to control strace interactivity.
692  * Allowed -p option to take comma or whitespace-separated list of PIDs.
693  * Added strace_log_merge script helper to merge timestamped "strace -ff"
694    log files.
695  * Implemented decoding of clock_adjtime, get_robust_list, migrate_pages,
696    preadv, prlimit64, process_vm_readv, process_vm_writev, pwritev,
697    recvmmsg, recvmsg, rt_tgsigqueueinfo, sendmmsg, setns, set_robust_list,
698    sched_rr_get_interval, splice, syslog, tee and vmsplice syscalls.
699  * Enhanced decoding of capget, capset, getrlimit, flistxattr, io_submit,
700    listxattr, setrlimit and swapon syscalls.
701  * Implemented decoding of loop and mtd ioctls.
702  * Added syscall entries for new linux syscalls.
703  * Added syscall entries for direct socket system calls on powerpc.
704  * Updated the list of errno constants.
705  * Updated lists of MSG_*, STA_*, and TCP_* constants.
706  * Regenerated the list of ioctl names from Linux 3.3.
707  * Enhanced switching between processes with different personalities.
708  * Enhanced signals reporting by using short signal names.
709  * Made ERESTART* messages more descriptive.
710  * Made parsing of numbers from strings more robust.
711  * Added support for compat_statfs64 and statfs64.f_flags.
712  * Changed read of data blocks to use single process_vm_readv syscall
713    (when available) instead of several PTRACE_PEEKDATA operations.
714  * Changed read of registers on x86 and x86-64 to use single PTRACE_GETREGS
715    operation instead of several PTRACE_PEEKUSER operations.
716  * Applied various optimizations to make strace work faster.
717
718* Bug fixes
719  * Implemented proper handling of real SIGTRAPs on kernels supporting
720    PTRACE_O_TRACESYSGOOD.
721    (Addresses Fedora bug #162774).
722  * Fixed sockaddr_un.sun_path name in decoded output.
723    (Addresses Debian bug #554946).
724  * Fixed to avoid potential core file clobbering on exit.
725    (Addresses Debian bug #656398).
726  * Fixed a typo in documentation.
727    (Addresses Debian bug #653309).
728  * Fixed decoding of timer id returned by timer_create.
729  * Fixed epoll_create1, epoll_wait and epoll_pwait decoding.
730  * Fixed *at syscalls flags decoding.
731  * Fixed ARM EABI 64-bit syscall's arguments decoding.
732  * Fixed semtimedop decoding on s390.
733  * Fixed osf_sigprocmask decoding on alpha.
734  * Fixed ipc and socket subcall decoding on several architectures.
735  * Corrected syscall entries for epoll_pwait, epoll_create, epoll_ctl,
736    epoll_wait, mincore, mlockall, prctl, reboot, sendfile, sendfile64,
737    sendmsg, sgetmask, ssetmask, swapon, tgkill and tkill syscalls.
738  * Corrected io_* syscall entries on ARM.
739  * Fixed PID prefix printing in "strace -oLOG -ff -p1 -p2 -p3" case.
740  * Fixed logging of unfinished lines in "strace -oLOG -ff" case.
741  * Fixed build when libaio-devel is not available.
742  * Fixed configure checks for PTRACE_* constants.
743  * Fixed compilation warnings remained on several architectures.
744
745* Portability
746  * Removed all non-Linux code.  After years of neglect, that dead code
747    just hampered further strace development.
748  * Linux kernel >= 2.6.18 is recommended.  Older versions might still
749    work but they haven't been thoroughly tested with this release.
750
751Noteworthy changes in release 4.6 (2011-03-15)
752==============================================
753
754* Changes in behavior
755  * Print diagnostic information about changes in personality mode to
756    standard error instead of standard output.
757
758* Improvements
759  * Implemented a new method of following clone, fork, and vfork
760    syscalls using the Linux kernel's explicit facilities for tracing
761    creation of threads and child processes.
762  * Implemented CLONE_PARENT and CLONE_UNTRACED flags handling.
763  * Implemented decoding of TLS syscalls on m68k.
764  * Implemented biarch support on powerpc64.
765  * Implemented biarch support for getrlimit() and setrlimit().
766  * Implemented decoding of struct ucred in getsockopt SO_PEERCRED.
767  * Implemented SOL_SCTP socket options decoding.
768  * Added HDIO_* ioctl names.
769    (Addresses Debian bug #450953).
770  * Added LOOP_* ioctl names.
771  * Updated lists of CLOCK_*, CLONE_*, MS_*, and SOL_* constants
772    to match Linux 2.6.37.
773  * Updated the list of IPPROTO_* constants to match netinet/in.h.
774  * Implemented decoding of HDIO_* and BLK* ioctls.
775  * Added MicroBlaze architecture support.
776  * Added new syscall entries to match Linux 2.6.37.
777  * Regenerated list of ioctl names from Linux 2.6.37.
778  * Enhanced signal notification decoding.
779  * Documented -C and -D options.
780
781* Bug fixes
782  * Fixed fetching syscall arguments on m68k.
783  * Fixed an error when judging whether a process has children.
784  * Fixed get/set_robust_list syscall numbers for powerpc.
785  * Fixed a corner case in printing clone flags.
786  * Fixed cross-compiling issues.
787  * Fixed build issues on powerpc64, SH and SPARC.
788  * Fixed syscall flags of fstatat*, mmap, mmap2, fadvise64*, swapoff,
789    fgetxattr, flistxattr, fremovexattr, epoll_create, fallocate,
790    fanotify_init, and fanotify_mark syscalls.
791  * Fixed decoding of get[ug]id, gete[ug]id and setfs[ug]id return values.
792  * Fixed biarch support in IO dumping.
793  * Fixed raw exit_group decoding.
794  * Fixed decoding of file descriptors on 64-bit architectures.
795  * Fixed a corner case in waitpid handling.
796    (Addresses Red Hat bug #663547).
797  * Fixed stat64 decoding on mips
798    (Addresses Debian bug #599028).
799  * Fixed misleading italics in the manual page.
800    (Addresses Debian bug #589323).
801
802Noteworthy changes in release 4.5.20 (2010-04-13)
803=================================================
804
805* Improvements
806  * Implemented decoding of new linux syscalls: inotify_init1, recvmmsg.
807  * Implemented basic decoding of new linux syscalls: preadv, pwritev,
808    rt_tgsigqueueinfo, perf_event_open.
809  * Enhanced decoding of recently added syscalls on non-x86 architectures
810    by replacing a bare decoder with elaborate parsers enabled earlier
811    for x86/x86-64.
812  * Implemented -C option to combine regular and -c output.
813    (Addresses Debian bug #466196)
814  * Enhanced decoding of mbind and mremap syscalls.
815  * Enhanced SOL_PACKET socket options decoding.
816  * Regenerated list of ioctl names from linux 2.6.33.
817  * Added TILE architecture support.
818
819* Bug fixes
820  * Fixed build with Linux kernel headers 2.6.32-rc5+.
821    (Addresses Debian bug #560516 and Fedora bug #539044)
822  * Fixed build on mips.
823  * Fixed handling of Linux systems without struct statfs64.
824  * Fixed reporting signal mask by sigreturn on powerpc.
825  * Fixed potential stack buffer overflow in select decoder.
826    (Addresses Fedora bug #556678)
827  * Corrected msgsnd indirect ipccall decoding.
828  * Corrected decoding of 64bit syscalls.
829    (Addresses Debian bug #570603)
830  * Corrected getsockopt decoding on architectures where
831    sizeof(long) > sizeof(int).
832    (Addresses Debian bug #494844)
833  * Corrected decoding of epoll_pwait.
834    (Addresses Debian bug #513014)
835  * Corrected handling of killed threads.
836
837Noteworthy changes in release 4.5.19 (2009-10-21)
838=================================================
839
840* Changes in behavior
841  * When command exits, strace now exits with the same exit status.
842    If command is terminated by a signal, strace terminates itself
843    with the same signal, so that strace can be used as a wrapper
844    process transparent to the invoking parent process.
845    When using -p option, the exit status of strace is zero unless
846    there was an unexpected error in doing the tracing.
847    (Addresses Fedora bug #105371 and Debian bug #37665)
848
849* Improvements
850  * Implemented decoding of new Linux syscalls: accept4, dup3,
851    epoll_create1, eventfd2, inotify_init1, pipe2, signalfd4.
852  * Implemented decoding of socket type flags introduced in Linux 2.6.27.
853  * Implemented decoding of accept4 socketcall.
854  * Enhanced prctl decoding.
855  * Enhanced nanosleep decoding.
856  * Enhanced ptrace decoding.
857  * Enhanced futex decoding.
858  * Enhanced CAP_* decoding.
859  * Enhanced SIOCS* ioctls decoding.
860  * Enhanced fcntl F_* flags decoding.
861  * Enhanced semop/semtimedop decoding.
862  * Updated ARM architecture support.
863  * Added Blackfin architecture support.
864  * Added AVR32 architecture support.
865  * Added CRIS architecture support.
866  * Made strace detect when traced process suddenly disappeared.
867
868* Bug fixes
869  * Fixed syscall numbers for tee and sync_file_range.
870    (Addresses Debian bug #503124)
871  * Fixed several bugs in strings decoder, including potential heap
872    memory corruption.
873    (Addresses Fedora bugs #470529, #478324 and #511035)
874  * Marked sendfile(2) as a network syscall.
875    (Addresses Debian bug #509499)
876  * Fixed accept(2) decoding.
877    (Addresses Debian bug #507573)
878  * Fixed sigtimedwait(2) decoding.
879  * Fixed build on ARM EABI.
880    (Addresses Debian bugs #520084 and #535564, and Fedora bug #507576)
881  * Fixed display of 32-bit fcntl(F_SETLK) on 64-bit architectures.
882    (Addresses Red Hat bug #471169)
883  * Fixed display of 32-bit argv array on 64-bit architectures.
884    (Addresses Fedora bug #519480)
885  * Fixed display of 32-bit struct sigaction on 64-bit architectures.
886  * Fixed HPPA architecture support.
887    (Addresses Debian bugs #437928 and #546619)
888
889Changes in 4.5.18
890==============
891* Bug fixes.
892* Support new Linux/PPC system call subpage_prot and PROT_SAO flag.
893* In sigaction system call, display sa_flags value along with SIG_DFL/SIG_IGN.
894
895Changes in 4.5.17
896==============
897* Many bug fixes.
898* -F is now deprecated, -f has traced vfork too on Linux for a long time now.
899* Print O_CLOEXEC, MSG_CMSG_CLOEXEC flag bits.
900* Improved output for prctl system call on Linux.
901* Improved support for Linux/ARM.
902* SA_NOMASK is now spelled SA_NODEFER, and SA_ONESHOT is spelled SA_RESETHAND.
903
904Changes in 4.5.16
905==============
906* Bug fixes.
907* Improved output for delete_module, futex, and mbind system calls on Linux.
908* Improved output for SG_IO ioctls on Linux.
909* Support new Linux system calls move_pages, utimensat, signalfd, timerfd,
910  eventfd, getcpu, epoll_pwait.
911
912Changes in 4.5.15
913==============
914* Bug fixes.
915* Several biarch improvements.
916* Improved output for adjtimex, sysctl, quotactl, mount, umount.
917* Support new Linux system calls *at, inotify*, pselect6, ppoll and unshare.
918
919Changes in 4.5.14
920==============
921* Bug fixes.
922* Accept numeric system calls in -e.
923
924Changes in 4.5.13
925==============
926* Bug fixes.
927* Introduce "-e trace=desc".
928
929Changes in 4.5.12
930==============
931* Bug fixes.
932* Better x86-64 support for IA32 processes.
933* Update PowerPC system calls.
934* Better printing for Linux aio system calls.
935
936Changes in 4.5.11
937==============
938* Quick fix release for build issues.
939* One fix for Linux/ARM system call table.
940
941Changes in 4.5.10
942==============
943* Bug fixes.
944* Print fault address for SIGSEGV/SIGBUS signals when available.
945
946Changes in 4.5.9
947==============
948* Bug fixes.
949* Improve socket ioctl printing.
950* Update Linux/IA64 syscall list.
951* Fix Linux/x86-64 syscall argument extraction for 32-bit processes.
952* Improve mount flags printing.
953* Support symbolic printing of x86_64 arch_prctl parameters.
954
955Changes in 4.5.8
956==============
957* Bug fixes.
958* Update syscall tables for Alpha, ARM, HPPA.
959* Support new Linux syscalls mbind, set_mempolicy, get_mempolicy, waitid.
960* Support Linux syscalls fadvise64, fadvise64_64, and epoll_*.
961* Improve ioctl command name matching.
962* Print RTC_* ioctl structure contents.
963* Support newer RLIMIT_* values.
964* Print struct cmsghdr details in sendmsg.
965
966Changes in 4.5.7
967==============
968* Bug fixes.
969* Print attribute values in *xattr system calls on Linux.
970* Include pread and pwrite calls in -e read and -e write tracing.
971* Update SO_* and IP_* value lists and add IPV6_* values for socket options.
972* Print clock_t values symbolically in Linux clock_* system calls.
973
974Changes in 4.5.6
975==============
976* Bug fixes, Linux ioctl updates.
977* David Miller contributed support for Linux/SPARC64.
978
979Changes in 4.5.5
980==============
981* Just bug fixes.
982
983Changes in 4.5.4
984==============
985* Update Linux ioctl lists.
986* Update PF_* and AF_* value lists.
987* The 4.5.3 -p behavior for NPTL threads applies only under -f, and got fixed.
988
989Changes in 4.5.3
990==============
991* Bug fixes.
992* On Linux using NPTL threads, -p will now attach to all threads in a process.
993* Handle new mq_* system calls in Linux 2.6.6 and later.
994
995Changes in 4.5.2
996==============
997* Bug fixes.
998* Report some new VM_* bit values on Linux.
999* Better output for Linux sched_* system calls.
1000
1001Changes in 4.5.1
1002==============
1003* Bug fixes.
1004* Display multiple ioctl name matches on Linux.
1005
1006Changes in 4.5
1007==============
1008* New port to AMD's x86-64 architecture. One strace binary can
1009  handle both new x86-64 and old i386 processes.
1010* Fixed support for LFS64 calls.
1011* New switch -E to add/remove environment variables for the command.
1012* Merged s390/s390x port.
1013* Trace an unbounded number of processes.
1014* Handle numerous new system calls in Linux 2.5, and new threads semantics.
1015* Fixed bugs with attach/detach leaving things stopped.
1016* Fixed traced process seeing ECHILD despite live, traced children
1017  in waitpid calls with WNOHANG.
1018* Stuart Menefy contributed a port to Linux/SH.
1019* Stephen Thomas contributed a port to Linux/SH64.
1020* Many other bug fixes.
1021
1022Changes in 4.4
1023==============
1024* Fix Linux/ia64 support, looks like someone renamed a few things on us
1025* Fix the ioctl setup for Linux, turned out it did not really work.
1026  Improve the ioctl extractor as well so we decode some more ones.
1027
1028Changes in 4.3.1
1029================
1030* compile fixes for Linux/mips
1031
1032Changes in 4.3
1033==============
1034* Linux ia64 and hppa ports added
1035* The usual Linux syscall updates (includes 32bit uid/gid support),
1036* Linux ioctl list updated
1037* Support IPv6 scope ids
1038* FreeBSD/i386 port added
1039* UnixWare and Solaris updates
1040* Better support for tracing multithreaded processes in Linux
1041
1042Changes in 4.2
1043==============
1044* Compiles on glibc2.0 systems again
1045* Linux/S390 port added
1046* The usual Linux syscall updates
1047* we can follow fork on arm now
1048
1049Changes in 4.1
1050================
1051* Linux/MIPS port added
1052* Lots of Linux updates again
1053* Improved IPv6 support
1054* Add strace-graph
1055
1056Changes in 4.0.1
1057================
1058* Minor bugfixes
1059* Compiles on glibc2.0 systems again
1060
1061Changes in 4.0
1062==============
1063* Get stat structure properly on Linux 64bit archs
1064* Personalities work again
1065* Compile correctly on SunOS again
1066* IRIX64 updates
1067* Solaris updates
1068
1069Changes in 3.99.1
1070=================
1071* Linux (ultra)sparc fixes
1072* Linux alpha fixes
1073* Minor cleanups
1074
1075Changes in 3.99
1076===============
1077* New maintainer
1078* add support for more Linux architectures (powerpc, sparc, arm)
1079* support lots more Linux syscalls
1080* fix signal handling
1081* add IPX and IPIP support
1082* check stray syscall after execv
1083* fix hanging children
1084
1085Changes in version 3.1
1086======================
1087
1088* Irix5 is supported
1089* Linux 68k is supported
1090* Linux alpha is supported
1091* configure is upgraded to autoconf 2.x
1092* using -f in combination with -e now works correctly
1093* output can be piped to a program
1094* tracing setuid programs works better
1095* it is now reasonable to install strace setuid to root in some circumstances
1096* new useful tracing names like file and process to trace whole
1097  classes of system calls, e.g. -efile traces all system calls that
1098  take a file name as an argument
1099* IPC calls on SunOS 4.1.x are decoded
1100* Linux program memory is reliably dereferenced
1101* Linux decodes at least the name of all syscalls as of pre2.0.4
1102* various cosmetic changes and bug fixes
1103
1104Changes from versions 2.x to version 3.0
1105========================================
1106
1107* filename arguments are neither abbreviated nor stringified
1108* string arguments are now true C strings using octal instead of hex by default
1109* preprocessor constants are never shortened (e.g. was RDONLY => now O_RDONLY)
1110* by default the output for multiple processes now goes into one file
1111* all structures, vectors, bitsets, etc. use consistent output formats
1112* the -c option now means count calls, -i does what the old -c used to do
1113
1114New Features in version 3.0
1115===========================
1116
1117* non-ascii strings can be optionally printed entirely in hex
1118* the output format is readable when multiple processes are generating output
1119* exit values are printed in an alignment column
1120* is is possible to suppress messages about attaching and detaching
1121* various tracing features can be enabled on a per syscall/signal/desc basis
1122* selective tracing of syscalls
1123* selective printing of syscall structures
1124* selective abbreviation of long structures on a per syscall basis
1125* selective printing of raw syscall arguments and results
1126* selective tracing of signals
1127* selective dumping of all I/O read from file descriptors
1128* selective dumping of all I/O written to file descriptors
1129* optional counting of time, calls, and errors for each syscall
1130