New in SystemTap 2.1 (Feb 14, 2013)
- Systemtap frontend (stap) changes:
- EMACS and VIM editor modes for systemtap source files are included / updated.
- The translator now eliminates duplicate tapset files between its preferred directory (as configured during the build with --prefix=/ or specified with the -I /path option), and files it may find under $XDG_DATA_DIRS. This should eliminate a class of conflicts between parallel system- and hand-built systemtap installations.
- The translator accepts a --suppress-time-limits option, which defeats time-related constraints, to allows probe handlers to run for indefinite periods. It requires the guru mode (-g) flag to work. Add the earlier --suppress-handler-errors flag for a gung-ho "just-keep-going" attitude.
- Some error messages and warnings now refer to additional information that is found in man pages. These are generally named error::FOO or warning::BAR (in the 7stap man page section) and may be read via % man error::FOO % man warning::BAR
- Systemtap script language changes:
- Perf event probes may now be read on demand. The counter probe is defined using the counter-name part: probe perf.type(0).config(0).counter("NAME"). The counter is read in a user space probe using @perf("NAME"), e.g. process("PROCESS").statement("func@file") {stat < < < @perf("NAME")}
- Perf event probes may now be bound to a specific task using the process-name part: probe perf.type(0).config(0).process("NAME") { } If the probed process name is not specified, then it is inferred from the -c CMD argument.
- The foreach looping construct can now sort aggregate arrays by the user's choice of aggregating function. Previously, @count was implied. e.g.: for each ([x,y] in array @sum +) { println(@sum(array[x,y])) }
- Proof of concept support for regular expression matching has been added:
- if ("aqqqqqb" =~ "q*b") { ... }
- if ("abc" !~ "q*b") { ... }
- The eventual aim is to support roughly the same functionality as the POSIX Extended Regular Expressions implemented by glibc. Currently missing features include extraction of the matched string and subexpressions, and named character classes ([:alpha:], [:digit:], &c).
- Systemtap runtime changes:
- The dyninst backend has improved in several aspects:
- The runtime now allows much more concurrency when probing multithreaded processes, and will also follow probes across forks.
- Several new probe types are now supported, including timers, function return, and process.begin/end and process.thread.begin/end.
- Semaphores for SDT probes are now set properly.
- Attaching to existing processes with -x PID now works.
- Systemtap tapset changes:
- New tapsets:
- choose_defined.stpm add @choose_defined() macro
- Added/changed tapsets for dyninst:
- ctime.stp ctime() returns "< invalid time >" when an error occurs
- context.stp add support for print_regs()
- Changed tapsets:
- nfs_proc.stp account for separate nfsv2/3/4 kernel modules
- context.stp add ppfunc() to parse the function name from pp()
- netfilter.stp fix error in decoding of ar_tha and ar_tpa fields
- The folowing tapset variables are deprecated in release 2.1 and may be removed in a future version:
- The 'send2queue' variable in the 'signal.send' probe.
- The 'oldset_addr' and 'regs' variables in the 'signal.handle' probe.
- The following tapset probes are deprecated in release 2.1 and may be removed in a future version:
- signal.send.return
- signal.handle.return
- Systemtap sample scripts:
- Tracing examples were updated to use ppfunc() instead of probefunc().
- New samples:
- perf.stp use perf.counter to access performance counters
- regex.stp report opened files whose names match a given regex
- threadstacks.stp override default new-pthread stack sizes
- mutex_contention.stp pthread mutex contention analysis
- ltrace.stp uprobes-based ltrace demo
- block.stp stapgames Breakout demo using input/output devices
- eater.stp stapgames Snake demo using input/output devices
- lifegame.stp stapgames Game of Life demo using input/output devices
- pingpong.stp stapgames Pong demo using input/output devices
- Changed samples:
- deviceseeks.stp switch to using ioblock_trace.request probe point
- Bugs fixed for this release:
- 1887 write emacs/vim editor mode for script language
- 6697 need more access_ok() checks in runtime/tapsets
- 11334 regular expression string matching
- 11576 per-process perf events
- 11955 signal tapsets don't match
- 12022 Allow foreach to order iterations for aggregates on @min @max and @avg operators
- 12231 reading perfctr events
- 12443 XDG_DATA_DIRS conflict between preinstalled and hand-built stap
- 12642 utrace: taskfinder misses events when main thread does not go through at least one quiesce
- 13022 probe module("*").function("*") does not work on arm
- 14178 Add a pure-userspace runtime mode
- 14245 Support debugfs mounted 0700
- 14390 separate process.**.return tests and mark UNSUPPORTED
- 14555 tolerate /proc/sys/kernel/kptr_restrict=2
- 14571 Make stapdyn multithreaded
- 14659 task_finder2 breaks ptrace apps
- 14701 stapdyn needs timer probe support
- 14705 stapdyn needs to set SDT semaphores
- 14707 Support stapdyn -x PID
- 14709 Support process.function.return in stapdyn
- 14712 VM_EXECUTABLE went to heaven
- 14714 stap flag for bigger --suppress-handler-errors hammer
- 14731 regression in buildok/thirty.stp
- 14735 stapdyn needs timing ('-t') support
- 14742 more complete dwz / DW_TAG_partial_unit support
- 14774 process.statement("*@file:*") probes don't match all functions
- 14781 kmem_cache conflict leads to panic & badness
- 14794 autoconf auto-enable dyninst if possible
- 14795 add stapgames
- 14804 Kernel panic when running hello world stap script
- 14820 hang when running semok/nodwf01.stp
- 14842 Old "-kelf" and "--ignore-dwarf" command line options should be removed
- 14883 let probefunc() not fail - or fail more informatively, on non-uprobes kernels
- 14900 collision between tapset locals and user globals: contexts
- 14929 staperrors man page
- 14949 cannot use systemtap on linux 3.7 intel x86_64
- 14957 foreach_aggrsort.exp test hangs on i686 rhel5 system
- 14997 DW_OP_rot mistranslation
- 15031 stapdyn needs a _stp_print_binary() runtime function
- 15059 session.print_error called frequently from listing_mode
- 15074 pthread_stacks.exp problems
- 15080 The kernel function 'signal_wake_up' is gone
- 15087 netfilter.arp tapset probes duplicate source/target addresses
- 15101 [PATCH] Stap sefaults when calling NSS_shutdown() which was not previously initialized
- 15112 Can't connect to stap-server via IPv6 raw hex addresses
- 15123 workaround for bad debuginfo for -mfentry