* systemtap 1.2 release notes
[not found] <4BA435EE.6080108@redhat.com>
@ 2010-03-23 0:02 ` Frank Ch. Eigler
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From: Frank Ch. Eigler @ 2010-03-23 0:02 UTC (permalink / raw)
To: systemtap; +Cc: linux-kernel, lwn
The systemtap team announces release 1.2.
prototype perf event and hw-breakpoint probing, security fixes,
error tolerance script language extensions, optimizations, tapsets,
interesting new sample scripts, kernel versions 2.6.9 through 2.6.34-rc
= Where to get it
http://sourceware.org/systemtap/ - our project page
http://sourceware.org/systemtap/ftp/releases/systemtap-1.2.tar.gz
http://koji.fedoraproject.org/koji/packageinfo?packageID=615
git tag release-1.2 (commit e36ba31aa5)
= How to build it
See the README and NEWS files at
http://sourceware.org/git/?p=systemtap.git;a=tree
Further information at http://sourceware.org/systemtap/wiki/
= Systemtap frontend (stap) changes
- Tapset-related man pages have been renamed. 'man -k 3stap' should
show the installed list, which due to prefixing should no longer
collide over ordinary system functions.
- User space marker arguments no longer use volatile if the version of
gcc, which must be at least 4.5.0, supports richer DWARF debuginfo.
Use cflags -DSTAP_SDT_VOLATILE=volatile or -DSTAP_SDT_VOLATILE= when
building the sys/sdt.h application to override this either way.
- A new command line flag '-W' forces systemtap to abort translation of
a script if any warnings are produced. It is similar to gcc's
-Werror. (If '-w' is also supplied to suppress warnings, it wins.)
- In order to limit potential impact from future security problems, the
stap-server process does not permit its being launched as root.
= Systemtap script language changes
- Type-casting can now use multiple headers to resolve codependencies.
@cast(task, "task_struct",
"kernel<linux/sched.h><linux/fs_struct.h>")->fs->umask
- A new construct for error handling is available. It is similar to c++
exception catching, using try and catch as new keywords. Within a
handler or function, the following is valid and may be nested:
try { /* arbitrary statements */ }
catch (er) { /* e.g. println("caught error ", er) */ }
- A new predicate @defined is available for testing whether a particular
$variable/expression is resolvable at translate time:
probe foo { if (@defined($bar)) log ("$bar is available here") }
- Adjacent string literals are glued together, making this construct
valid:
probe process("/usr" @1 "/bin").function("*") { ... }
= Systemtap tapset changes
- Prototype support for "perf events", where the kernel supports the
2.6.33 in-kernel API. Probe points may refer to low-level
perf_event_attr type/config numbers, or to a number of aliases
defined in the new perf.stp tapset:
probe perf.sw.cpu_clock, perf.type(0).config(4) { }
- On recent kernels, for some architectures/configurations, hardware
breakpoint probes are supported. The probe point syntax is:
probe kernel.data(ADDRESS).write
probe kernel.data(ADDRESS).length(LEN).write
probe kernel.data("SYMBOL_NAME").write
- Miscellaneous other additions:
- atomic tapset for kernel atomic variables
- nfsderror() function to translate NFS error numbers
- more task_time and proc_mem variants
- functions for accessing process command-lines
= New script examples
- general/varwatch.stp Watch a variable changing value in a thread
- io/iodevstats.stp List executables R/W the most data by device
- io/nfs_func_users.stp Tally the NFS functions used by each process
- process/pfiles.stp Print process file descriptors
- profiling/fntimes.stp Show functions taking longer than usual
= Contributors for this release
Charley Wang, Dave Brolley, David J. Wilder, David Smith, Eugene Teo,
Eugeniy Meshcheryakov, Frank Ch. Eigler, Josh Stone, Mark Wielaard,
Nobuhiro Tachino, Petr Muller, Prerna Saxena, Przemyslaw Pawelczyk,
Roland McGrath, Stan Cox, Steve Dickson, Tim Moore, Wenji Huang,
William Cohen
Thanks to Josh Stone for compiling these notes.
= Examples of tested kernel versions
2.6.9 (el4/i686)
2.6.18 (el5/ia64/i686/x86_64)
2.6.30.5 (f11/i686/x86_64)
2.6.31 (f12/i686/x86_64)
2.6.32.3 (rawhide/x86_64)
2.6.34-rc1 (rawhide/x86_64)
= Known issues with this release
- When using the systemtap client and server udp port 5353 must be
open in your firewall in order for the clent to find servers using
avahi-browse.
- The stap-server may not be sufficiently robust to operate on an open
untrusted network.
- Some kernel crashes continue to be reported when a script probes
broad kernel function wildcards.
= Bugs fixed for this release
909 perf counter events, perfmon? kernel API
3859 SystemTap Control Library
6954 ++ operations not triggering automatic global printing
9737 test.tcl aborts testrun when using certain expect versions.
9738 Running a stap script throws up compilation error
9931 diagnostic aids for module cache collisions
10257 sprint(@hist_*) doesn't parse
10331 ssl certificate use error
10435 Hardware breakpoint support
10451 don't start client/server tests if avahi-daemon is not running
10493 runtime/time.c: need autoconf for cpu_khz
10641 -m NAME should be disabled in --unprivileged mode
10690 need way to produce bigger procfs output
10719 Implement constant-folding optimizations
10747 preprocessor permits invalid construct
10831 Preserve the derivation chain for sdt and label probes
10835 stap-stop-server doesn't work for failed starts
10848 enforcement of memory limits
10901 use AC_SYS_LARGEFILE or such for stat*64 use
10905 stap-server initscript improvements
11004 error catching syntax
11005 @defined() predicate for compile-time $var error catching
11059 No dtrace script documentation
11075 RFE: -Werror
11078 avoid procfs race condition
11105 fix vulnerability of stap-server to spacious incoming arguments
11114 librpm autoconf search too complex
11124 user space markers inefficient due to volatile args
11173 markers get a bad address in prelinked libraries
11195 argument expansion needs better recursion protection
11196 Retrieving variables from marker locations broken on x86_64
11201 Distributed scripts should not be removed on clean
11205 use assigned stap-server uid/gid 155/155 in systemtap.spec
11208 auto-concatenate string literals
11210 3stap man pages colliding with 3
11220 arrays can't store MAXSTRINGLEN strings
11223 procfs write probe problem
11224 setting module arguments needs to be tested/documented
11229 Error message for CONFIG_UTRACE could mention kernel headers
11234 __get_argv can overflow its return buffer
11246 Add better control over caching
11256 harden --unprivileged mode
11269 syscall.mmap decoding $fd incorrectly with MAP_ANONYMOUS
11270 The 'nd_syscall' tapset needs a testcase
11275 Don't print the full usage after command line error
11277 _stp_text_str uses bad octal escapes
11281 Negative -D value triggers ERROR: Safety pattern mismatch
11282 FAIL: RUNTIME1 was cached
11286 Client-only Arguments Passed to the Server
11296 sdt.h test cases don't work from systemtap-testsuite rpm
11309 ditch runtime/uprobes chmod in systemtap.spec
11326 Can't optimize away bad $vars in return probes
11336 procfs runtime code holding mutex too long
11342 last_stmt is sometimes not available for errors
11346 @defined() with '--skip-badvars' doesn't work correctly
11352 sdt.exp kprobe tests FAIL with SEGV
11360 Bad interaction between -L and @defined
11363 no logrotate support for stap server log
11364 cxxclass.exp fails with latest std.h and g++ (Red Hat 4.4.3-4)
11366 @defined() and unoptimized stap -u don't work nicely together
11370 multi-header @cast
11372 proc_mem.stp needs better testing
11402 pipe2 syscall not supported
11405 tolerate/ignore tapsets with syntax errors
11406 Add dup2, epoll_create1, eventfd2, inotify_init1 and signalfd4 to syscall tapset
CVE-2009-4273 stap-server command injection
CVE-2010-0411 __get_argv() tapset fn buffer overflow
CVE-2010-0412 stap-server command injection part 2
= Test results on various systems
- After running "sudo make installcheck" from the test suite, on a
suitably equipped machine (kernel debugging data and other stuff
installed), you should see 1000-1100 passes and a small handful of
failures. Those enjoying utrace in their kernels should see several
hundred more passes.
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