The SystemTap team announces release 2.4, "virtual world"! smarter error reporting, better suggestions, virtual machine probing, .gnu_debugdata support, improved memory allocation, and more!
= Where to get it http://sourceware.org/systemtap/ - our project page http://sourceware.org/systemtap/ftp/releases/systemtap-2.4.tar.gz http://koji.fedoraproject.org/koji/packageinfo?packageID=615 git tag release-2.4 (commit aa7b1e0) There have been over 247 commits since the last release. There have been over 35 bugs fixed / features added since the last release. = 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 - Better suggestions are given in many of the semantic errors in which alternatives are provided. Additionally, suggestions are now provided when plt and trace probes could not be resolved. For example, kernel.trace("sched_siwtch") will suggest 'sched_switch'. - SystemTap is now smarter about error reporting. Errors from the same source are considered duplicates and suppressed. A message is displayed on exit if any errors/warnings were suppressed. - SystemTap now supports probing inside virtual machines using the libvirt and unix schemes, e.g. stap -ve 'probe timer.s(1) { printf("hello!\n") }' \ --remote=libvirt://MyVirtualMachine Virtual machines managed by libvirt can be prepared using stapvirt. See stapvirt(1) and the --remote option in stap(1) for more details. - SystemTap now checks for and uses (when available) the .gnu_debugdata section which contains a subset of debuginfo, useful for backtraces and function probing = SystemTap script language changes - For systems with in-kernel utrace, 'process.end' and 'thread.end' probes will hit before the target's parent process is notified of the target's death. This matches the behavior of newer kernels without in-kernel utrace. = SystemTap runtime changes - The stap-server client & server code now enable all SSL/TLS ciphers rather than just the "export" subset. - Statistics aggregate typed objects are now implemented locklessly, if the translator finds that they are only ever read (using the foreach / @count / etc. constructs) in a probe-begin/end/error. - SystemTap map variables are now allocated with vmalloc() instead of with kmalloc(), which should cause memory to be less fragmented. - Although SystemTap itself requires elfutils 0.148+, staprun only requires elfutils 0.142+, which could be useful with the '--disable-translator' configure switch. - Under FIPS mode (/proc/sys/crypto/fips_enabled=1), staprun will refuse to load SystemTap modules (since these are not normally signed with the kernel's build-time keys). This protection may be suppressed with the $STAP_FIPS_OVERRIDE environment variable. = SystemTap tapset changes macros.stpm new '@MAXSTRINGLEN' macro context-caller.stp use the new '@MAXSTRINGLEN' macro instead of %{ MAXSTRINGLEN %} to avoid problens for unprivileged users context-symbols.stp ditto ucontext-symbols.stp ditto ucontext.stp ditto uconversions.stp ditto and new function user_string_n2_quoted() context.stp fix cmdline_arg() processing dentry.stp new inode_path() function which tries to locate the vfsmount containing an inode nd_syscalls.stp (1) fix syscall.{execve,compat_execve} for older kernels (2) break the 'mmap2' probe alias down into subprobes to better convert 'pgoff' syscalls.stp (1) & (2) as above and (3) fix syscall.accept probe alias optionality memory.stp correct VM_FAULT_MINOR conditional handling and protect __pa() call with virt_addr_valid() nfs_proc.stp update probes to handle removal of NFSv2 signal.stp update signal.pending[.return] probe aliases registers.stp on s390, new _stp_get_kernel_stack_param() function to get stack parameters aux_syscalls.stp decode SIGTRAP|0x80 from PTRACE_O_TRACESYSGOOD - Several syscall tapsets which read user buffers of known length will now use user_string_n2_quoted rather than user_string_n_quoted(). - The syscall/nd_syscall tapsets had multiple probes split into subprobes to avoid using symname(addr()). - The s390 syscalls.stp tapset had multiple probes updated to handle newer kernels with renamed parameters. = SystemTap sample scripts - New samples: last_100_frees.stp log recent free(3) libc calls along with a userspace backtrace at those moments futexes2.stp watches just shared futex syscalls on the system and prints contention info on exit semop-watch.stp prints a timed trace of semop(2)/semtimedop(2) syscalls strace.stp loosely emulates strace, can be applied to individual processes (via -c/-x) or entire system - Changed samples: badname.stp update for newer kernels eventcount.stp add -G lines=NNN option tcpdumplike.stp demonstrates recently added UDP tapset by also printing out UDP packets deviceseeks.stp handle older kernel's names for sector size field numa_faults.stp update to tolerate exception now thrown by addr_to_node() tapset function threadstacks.stp updated for glibc 2.17 changes regarding pthread stack allocation periodic.stp tweak to operate without kernel debuginfo = Examples of tested kernel versions 2.6.9 (x86) 2.6.18 (x86) 2.6.32 (x86) 3.10.0 (x86_64) 3.11.6 (x86_64) = Known issues with this release - Some kernel crashes continue to be reported when a script probes broad kernel function wildcards. (PR2725) - 32-on-64 bit userspace unwinding is truncated on older kernels, such as 2.6.32 (PR15757) - The dyninst backend is still very much a prototype, with a number of issues, limitations, and general teething woes. For instance: + lack of support for multiarch/cross-instrumentation + tapset functions are still incomplete relative to what is supported when the kernel backend is active + exception handling becomes completely broken in programs instrumented by the current version of dyninst (PR14702) + command line interrupts are slightly mishandled (PR15049) + not all registers are made available on 32-bit x86 (PR15136) See dyninst/README and the systemtap/dyninst Bugzilla component (http://tinyurl.com/stapdyn-PR-list) if you want all the gory details about the state of the feature. = Contributors for this release Dave Brolley, David Smith, Frank Ch. Eigler, Jonathan Lebon, Josh Stone, Lukas Berk, Mark Wielaard, Martin Cermak*, Masanari Iida, Miroslav Franc*, Naresh Kamboju*, Paddie O'Brien*, Serguei Makarov, Stan Cox, Timo Juhani Lindfors, Vincent Bernat*, William Cohen Special thanks to new contributors, marked with '*' above. Special thanks to Jonathan Lebon for compiling these notes. = Bugs fixed for this release <http://sourceware.org/PR#####> 4331 systemtap.stress/current.stp need to be updated for s390x 6764 Execution of probefunc.exp causes system hang on s390 system 9822 reduce timer load 10088 on s390x, the translator gets an assertion 11751 on s390x, externalvar.exp gets libdwfl failures 13078 investigate qemu virtio-serial channel for talking to stap-sh 13974 sdt.h is incompatible with clang 14960 frame size too large for systemtap.examples/process/psig 15625 unprivileged_embedded_C test confused by stub registers.stp 15663 Failing to remove the stap kernel modules on kernel 3.9.4 15782 nss usage bugs - PR_Read returning short results 15788 tarballs should be PGP signed 15789 ERROR: couldn't initialize gettimeofday 15793 Kernel panic when running systemtap's test suite with kernel 3.10.1 15803 systemtap 2.3 testsuite crashes linux 3.10 sometimes at netdev/enter_netfilter_probe_0 15805 maps should not be allocated with k*alloc 15865 nfs_proc.stp needs to be handle NFSv2 support being removed 15866 on rawhide, the 'signal.pending' and 'signal.pending.return' probe aliases are broken 15872 on rawhide, we're getting odd client.exp test failures 15874 the systemtap.base/onoffprobe.exp testcase times out 15875 the ptrace.exp testcase will fail if 'strace' isn't present on the system 15876 The ptridx.exp testcase has timeout errors 15881 unprivileged_myproc.exp test fails on rawhide 15900 syntax errors in server_locale.exp 15906 don't try to run modules in kernel-fips mode 15913 on s390x, nd_syscall testsuite failures when accessing arguments 1 and 6 15928 the memory1.exp testcase is accessing user memory as kernel memory 15937 On arm fc19 unable to find $whence argment for kernel.function("sys_llseek").call 15961 nd_syscall.exp failure on i686 15980 uprobes MAXSKIPPED not overruled by --suppress-handler-errors 15982 process.end probes broken on RHEL6 16019 limit number of similar semantic errors output 16057 task_dentry_path fails to cross mount points 16058 syscall.mmap/nd_syscall.mmap probe alias problem 16096 on i686, the nd_syscall tapset is broken -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
