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