Commit Graph

89 Commits

Author SHA1 Message Date
Mark Johnston
b69b2ff588 Allocate the probe ID unrhdr before the DTrace kld_* event handlers are
registered. Otherwise there is a small window during which probe IDs may be
allocated before the unrhdr is allocated.

MFC after:	2 weeks
2013-12-31 15:41:16 +00:00
Mark Johnston
a333376bba Revert r260091. The vmem calls seem to be slower than the *_unr() calls that
they replaced, which is important considering that probe IDs are allocated
during process startup for USDT probes.
2013-12-31 15:37:51 +00:00
Mark Johnston
b9c04b396a Now that vmem(9) is available, use vmem arenas to allocate probe and
aggregation IDs, as is done in the upstream illumos code. This still
requires some FreeBSD-specific code, as our vmem API is not identical to the
one in illumos.

Submitted by:	Mike Ma <mikemandarine@gmail.com>
2013-12-30 17:37:32 +00:00
Justin Hibbits
ad5017b513 Fix a brain-o. I had misread the limit as a size, but it's a pointer.
Submitted by:	Howard Su
MFC after:	2 weeks
X-MFC-with:	r259668
2013-12-21 00:37:32 +00:00
Justin Hibbits
a76f5d59f4 Fix a couple bugs in FBT PowerPC. Clamp the size to a 'instruction size' not
'byte size', and fix a typo.

MFC after:	2 weeks
2013-12-20 23:18:14 +00:00
Andriy Gapon
d9fae5ab88 dtrace sdt: remove the ugly sname parameter of SDT_PROBE_DEFINE
In its stead use the Solaris / illumos approach of emulating '-' (dash)
in probe names with '__' (two consecutive underscores).

Reviewed by:	markj
MFC after:	3 weeks
2013-11-26 08:46:27 +00:00
Attilio Rao
54366c0bd7 - For kernel compiled only with KDTRACE_HOOKS and not any lock debugging
option, unbreak the lock tracing release semantic by embedding
  calls to LOCKSTAT_PROFILE_RELEASE_LOCK() direclty in the inlined
  version of the releasing functions for mutex, rwlock and sxlock.
  Failing to do so skips the lockstat_probe_func invokation for
  unlocking.
- As part of the LOCKSTAT support is inlined in mutex operation, for
  kernel compiled without lock debugging options, potentially every
  consumer must be compiled including opt_kdtrace.h.
  Fix this by moving KDTRACE_HOOKS into opt_global.h and remove the
  dependency by opt_kdtrace.h for all files, as now only KDTRACE_FRAMES
  is linked there and it is only used as a compile-time stub [0].

[0] immediately shows some new bug as DTRACE-derived support for debug
in sfxge is broken and it was never really tested.  As it was not
including correctly opt_kdtrace.h before it was never enabled so it
was kept broken for a while.  Fix this by using a protection stub,
leaving sfxge driver authors the responsibility for fixing it
appropriately [1].

Sponsored by:	EMC / Isilon storage division
Discussed with:	rstone
[0] Reported by:	rstone
[1] Discussed with:	philip
2013-11-25 07:38:45 +00:00
Justin Hibbits
de950c79f3 Fix the function search space.
Submitted by:	Howard Su
2013-11-20 01:33:13 +00:00
Mark Johnston
57170f49f2 Remove references to an unused fasttrap probe hook, and remove the
corresponding x86 trap type. Userland DTrace probes are currently handled
by the other fasttrap hooks (dtrace_pid_probe_ptr and
dtrace_return_probe_ptr).

Discussed with:	rpaulo
2013-10-31 02:35:00 +00:00
Mark Johnston
9c06d5a051 Do some cleanup of the SDT code. In particular,
* Remove the unused sdt cdev.
* Don't bother keeping a list of probes in struct sdt_prov; it's not needed.
* Invoke sdt_load and sdt_unload from the module handler instead of
  registering separate SYSINITs.
* Keep to within 80 columns.
* Check for errors from dtrace_unregister().
2013-10-26 06:23:51 +00:00
Justin Hibbits
594ce9ad6f ELF PowerPC64 ABI puts the LR save word at 16 byte offset, not 8. 2013-10-25 00:17:12 +00:00
Mark Johnston
7e75d58610 When fetching function arguments out of a frame on amd64, explicitly select
the register based on the argument index rather than relying on the fields
in struct reg to be in the right order. This assumption is incorrect on
FreeBSD and generally led to bogus argument values for the sixth argument
of PID and USDT probes; the first five are passed directly to dtrace_probe()
via the fasttrap trap handler and so were correctly handled.

MFC after:	2 weeks
2013-10-21 04:15:55 +00:00
Mark Johnston
e572bc11ec Add a function, memstr, which can be used to convert a buffer of
null-separated strings to a single string. This can be used to print the
full arguments of a process using execsnoop (from the DTrace toolkit) or
with the following one-liner:

dtrace -n 'syscall::execve:return {trace(curpsinfo->pr_psargs);}'

Note that this relies on the process arguments being cached via the struct
proc, which means that it will not work for argvs longer than
kern.ps_arg_cache_limit. However, the following rather non-portable
script can be used to extract any argv at exec time:

fbt::kern_execve:entry
{
    printf("%s", memstr(args[1]->begin_argv, ' ',
        args[1]->begin_envv - args[1]->begin_argv));
}

The debug.dtrace.memstr_max sysctl limits the maximum argument size to
memstr(). Thanks to Brendan Gregg for helpful comments on freebsd-dtrace.

Tested by:	Fabian Keil (earlier version)
MFC after:	2 weeks
2013-10-16 01:39:26 +00:00
Mark Johnston
cb7320ce7b Initialize and free the DTrace taskqueue in the dtrace module load/unload
handlers rather than in the dtrace device open/close methods. The current
approach can cause a panic if the device is closed which the taskqueue
thread is active, or if a kernel module containing a provider is unloaded
while retained enablings are present and the dtrace device isn't opened.

Submitted by:	gibbs (original version)
Reviewed by:	gibbs
Approved by:	re (glebius)
MFC after:	2 weeks
2013-10-08 12:56:46 +00:00
Davide Italiano
d56b4cd4ac - Use make_dev_credf(MAKEDEV_REF) instead of the race-prone make_dev()+
dev_ref() in the clone handlers that still use it.
- Don't set SI_CHEAPCLONE flag, it's not used anywhere neither in devfs
(for anything real)

Reviewed by:	kib
2013-09-07 13:45:44 +00:00
Justin Hibbits
7fb93a40c2 Whitespace cleanup. 2013-09-02 23:22:05 +00:00
Justin Hibbits
f0bd82a11b Fixes for DTrace on PowerPC:
- Implement dtrace_getarg()
- Sync fbt with x86, and fix a typo.
- Pull in the time synchronization code from amd64.
2013-08-31 16:30:20 +00:00
Mark Johnston
29f4e216f2 Rename the kld_unload event handler to kld_unload_try, and add a new
kld_unload event handler which gets invoked after a linker file has been
successfully unloaded. The kld_unload and kld_load event handlers are now
invoked with the shared linker lock held, while kld_unload_try is invoked
with the lock exclusively held.

Convert hwpmc(4) to use these event handlers instead of having
kern_kldload() and kern_kldunload() invoke hwpmc(4) hooks whenever files are
loaded or unloaded. This has no functional effect, but simplifes the linker
code somewhat.

Reviewed by:	jhb
2013-08-24 21:13:38 +00:00
Andriy Gapon
17a9f2d4db fbt: drop a local write-only variable
Discovered with:	gcc46
MFC after:	4 days
2013-08-23 14:41:27 +00:00
Justin Hibbits
7ccb72b31f Make dtrace_copy() actually work on PowerPC. Although unused currently,
it may be used in the future by dtrace.
2013-08-22 02:54:20 +00:00
Justin Hibbits
cc117e2773 Fix some ppc64 dtrace bugs, and enable systrace_freebsd32 for ppc64. 2013-08-19 05:10:46 +00:00
Mark Johnston
7bc992c037 Add a "translated type" argument to SDT_PROBE_ARGTYPE() and add some macros
which allow one to define SDT probes that specify translated types. The idea
is to make it easy to write SDT probe definitions that can work across
multiple operating systems. In particular, this makes it possible to port
illumos SDT probes to FreeBSD without changing their argument types, so long
as the appropriate translators are defined. Then DTrace scripts written for
Solaris/illumos will work on FreeBSD without any changes.

MFC after:	1 week
2013-08-17 22:02:26 +00:00
Mark Johnston
12ede07ab8 Use kld_{load,unload} instead of mod_{load,unload} for the linker file load
and unload event handlers added in r254266.

Reported by:	jhb
X-MFC with:	r254266
2013-08-14 00:42:21 +00:00
Mark Johnston
8776669b53 FreeBSD's DTrace implementation has a few problems with respect to handling
probes declared in a kernel module when that module is unloaded. In
particular,

* Unloading a module with active SDT probes will cause a panic. [1]
* A module's (FBT/SDT) probes aren't destroyed when the module is unloaded;
  trying to use them after the fact will generally cause a panic.

This change fixes both problems by porting the DTrace module load/unload
handlers from illumos and registering them with the corresponding
EVENTHANDLER(9) handlers. This allows the DTrace framework to destroy all
probes defined in a module when that module is unloaded, and to prevent a
module unload from proceeding if some of its probes are active. The latter
problem has already been fixed for FBT probes by checking lf->nenabled in
kern_kldunload(), but moving the check into the DTrace framework generalizes
it to all kernel providers and also fixes a race in the current
implementation (since a probe may be activated between the check and the
call to linker_file_unload()).

Additionally, the SDT implementation has been reworked to define SDT
providers/probes/argtypes in linker sets rather than using SYSINIT/SYSUNINIT
to create and destroy SDT probes when a module is loaded or unloaded. This
simplifies things quite a bit since it means that pretty much all of the SDT
code can live in sdt.ko, and since it becomes easier to integrate SDT with
the DTrace framework. Furthermore, this allows FreeBSD to be quite flexible
in that SDT providers spanning multiple modules can be created on the fly
when a module is loaded; at the moment it looks like illumos' SDT
implementation requires all SDT probes to be statically defined in a single
kernel table.

PR:		166927, 166926, 166928
Reported by:	davide [1]
Reviewed by:	avg, trociny (earlier version)
MFC after:	1 month
2013-08-13 03:10:39 +00:00
Andriy Gapon
c319ea15f4 opensolaris code: translate INVARIANTS to DEBUG and ZFS_DEBUG
Do this by forcing inclusion of
sys/cddl/compat/opensolaris/sys/debug_compat.h
via -include option into all source files from OpenSolaris.
Note that this -include option must always be after -include opt_global.h.

Additionally, remove forced definition of DEBUG for some modules and fix
their build without DEBUG.

Also, meaning of DEBUG was overloaded to enable WITNESS support for some
OpenSolaris (primarily ZFS) locks.  Now this overloading is removed and
that use of DEBUG is replaced with a new option OPENSOLARIS_WITNESS.

MFC after:	17 days
2013-08-06 15:51:56 +00:00
Andriy Gapon
0f09691df8 dtrace disassembler: take the latest/last CDDL code from OpenSolaris
OpenSolaris version is:
13108:33bb8a0301ab
6762020 Disassembly support for Intel Advanced Vector Extensions (AVX)

This corresponds to Illumos-gate (github) version
ab47273fedff893c8ae22ec39ffc666d4fa6fc8b

MFC after:	3 weeks
2013-07-29 16:56:38 +00:00
Mark Johnston
46d27dbb38 Hide references to mod_lock. In FreeBSD it is always acquired with the
provider lock held, so its use has no effect.
2013-07-05 22:42:10 +00:00
Mark Johnston
837610eb04 The dtmalloc provider uses the short description of a malloc type as the
function name of its corresponding DTrace probes. These descriptions may
contain whitespace, but probe names cannot, so just replace any whitespace
with underscores when creating probes.

MFC after:	1 week
2013-06-28 03:14:40 +00:00
Mark Johnston
f263e440d4 SDT probes can directly pass up to five arguments as arguments to
dtrace_probe(). Arguments beyond these five must be obtained in an
architecture-specific way; this can be done through the getargval provider
method, and through dtrace_getarg() if getargval isn't overridden.

This change fixes two off-by-one bugs in the way these arguments are fetched
in FreeBSD's DTrace implementation. First, the SDT provider must set the
aframes parameter to 1 when creating a probe. The aframes parameter controls
the number of frames that dtrace_getarg() will step over in order to find
the frame containing the extra arguments. On FreeBSD, dtrace_getarg() is
called in SDT probe context via

dtrace_probe()->dtrace_dif_emulate()->dtrace_dif_variable->dtrace_getarg()

so aframes must be 3 since the arguments are in dtrace_probe()'s frame; it
was previously being called with a value of 2 instead. illumos uses a
different aframes value for SDT probes, but this is because illumos SDT
probes fire by triggering the #UD fault handler rather than calling
dtrace_probe() directly.

The second bug has to do with the way arguments are grabbed out
dtrace_probe()'s frame on amd64. The code currently jumps over the first
stack argument and retrieves the rest of them using a pointer into the
stack. This works on i386 because all of dtrace_probe()'s arguments will be
on the stack and the first argument is the probe ID, which should be
ignored. However, it is incorrect to ignore the first stack argument on
amd64, so we correct the pointer used to access the arguments.

MFC after:	2 weeks
2013-06-02 01:05:36 +00:00
Mark Johnston
18161786c6 Port the SDT test now that it's possible to create SDT probes that take
seven arguments.

The original test uses Solaris' uadmin system call to trigger the test
probe; this change adds a sysctl to the dtrace_test module and gets the test
program to trigger the test probe via the sysctl handler.

The test is currently failing on amd64 because of some bugs in the way that
probe arguments beyond the first five are obtained - these bugs will be
fixed in a separate change.
2013-06-02 00:33:36 +00:00
Mark Johnston
09e6105ff4 Bring back part of r249367 by adding DTrace's temporal option, which allows
users to guarantee that the output of DTrace scripts will be time-ordered.
This option is enabled by adding the line

  #pragma D option temporal

to the beginning of a script, or by adding '-x temporal' to the arguments of
dtrace(1).

This change fixes a bug in the original port of the temporal option. This
bug was causing some assertions to fail, so they had been disabled; in this
revision the assertions are working properly and are enabled.

The DTrace version number has been bumped from 1.9.0 to 1.9.1 to reflect
the language change that's being introduced.

This change corresponds to part of illumos-gate commit e5803b76927480:
  3021 option for time-ordered output from dtrace(1M)

Reviewed by:	pfg
Obtained from:	illumos
MFC after:	1 month
2013-05-12 16:26:33 +00:00
Andriy Gapon
aaf2546b67 fbt_getargdesc: correctly handle types for return probes
MFC after:	6 days
2013-03-23 08:52:50 +00:00
Andriy Gapon
a47016e9a9 fbt_typoff_init: fix an off by one in determining required memory size
This issue would be silent most of the time, but if the requested memory
is a multiple of a page size, then accessing one element beyond the end
would lead to a kernel page fault.
Otherwise, the unlucky last type would just be inaccessible.

Reported by:	glebius
Tested by:	glebius
MFC after:	6 days
2013-03-23 08:48:44 +00:00
Justin Hibbits
80a5635c8b Add FBT for PowerPC DTrace. Also, clean up the DTrace assembly code,
much of which is not necessary for PowerPC.

The FBT module can likely be factored into 3 separate files: common,
intel, and powerpc, rather than duplicating most of the code between
the x86 and PowerPC flavors.

All DTrace modules for PowerPC will be MFC'd together once Fasttrap is
completed.
2013-03-18 05:30:18 +00:00
Sergey Kandaurov
3c56b4f165 Fix warning: comparison of unsigned expression < 0 is always false.
Reported by:	clang
2013-02-08 09:54:53 +00:00
Justin Hibbits
7e7a9efdb5 Fix the PowerPC DTrace copy functions. The kernel doesn't hold the same view to
the user map, so use the md copy in/out functions provided by the kernel.

MFC with:	r242723
2013-02-03 00:19:34 +00:00
Ryan Stone
6969ef6656 Correct a series of errors in the hand-rolled locking for drace_debug.c:
- Use spinlock_enter()/spinlock_exit() to prevent a thread holding a
  debug lock from being preempted to prevent other threads waiting
  on that lock from starvation.

- Handle the possibility of CPU migration in between the fetch of curcpu
  and the call to spinlock_enter() by saving curcpu in a local variable.

- Use memory barriers to prevent reordering of loads and stores of the
  data protected by the lock outside of the critical section

- Eliminate false sharing of the locks by moving them into the structures
  that they protect and aligning them to a cacheline boundary.

- Record the owning thread in the lock to make debugging future problems
  easier.

Reviewed by:	rpaulo (initial version)
MFC after:	2 weeks
2012-12-23 15:50:37 +00:00
Justin Hibbits
c757049235 Implement DTrace for PowerPC. This includes both 32-bit and 64-bit.
There is one known issue:  Some probes will display an error message along the
lines of:  "Invalid address (0)"

I tested this with both a simple dtrace probe and dtruss on a few different
binaries on 32-bit.  I only compiled 64-bit, did not run it, but I don't expect
problems without the modules loaded.  Volunteers are welcome.

MFC after:	1 month
2012-11-07 23:45:09 +00:00
George V. Neville-Neil
d638e8dcde Change UL to ULL since time is 32 bits.
Pointed out by: avg@
MFC after:	2 weeks
2012-07-17 14:36:40 +00:00
George V. Neville-Neil
57d025c338 Add support for walltimestamp in DTrace.
Submitted by:	Fabian Keil
MFC after:	2 weeks
2012-07-16 20:17:19 +00:00
Andriy Gapon
e0bc3c3d99 r237748 continuation: fix nopw (0f 1f) behavior with respect to modifiers
To do: proper merge with Illumos vendor area.

Reported by:	emaste
Tested by:	emaste
Obtained from:	Illumos commit 13442:4adbe6de60c8
MFC after:	5 days
2012-07-06 14:45:30 +00:00
Andriy Gapon
7e18e35b14 r237748 continuation: segment-override prefixes are not invalid in long mode
Update DTrace disassembler accordingly.  The code to treat the prefixes
as null prefixes was already in place.
Although in practice compilers seem to generate only cs-prefix for use
in long NOPs, the same treatment is applied to all of cs, ds, es, ss for
consistency.

Reported by:	emaste
Tested by:	emaste
Obtained from:	Illumos commit 13442:4adbe6de60c8 (+ local changes)
MFC after:	5 days
2012-07-06 14:41:02 +00:00
Andriy Gapon
f724c6a137 dtrace instruction decoder: add 0x0f 0x1f NOP opcode support
According to the AMD manual the whole range from 0x09 to 0x1f are NOPs.
Intel manual mentions only 0x1f.  Use only Intel one for now, it seems
to be the one actually generated by compilers.
Use gdb mnemonic for the operation: "nopw".

[1] AMD64 Architecture Programmer's Manual
    Volume 3: General-Purpose and System Instructions
[2] Software Optimization Guide for AMD Family 10h Processors
[3] Intel(R) 64 and IA-32 Architectures Software Developer’s Manual
    Volume 2 (2A, 2B & 2C): Instruction Set Reference, A-Z

Tested by:	Fabian Keil <freebsd-listen@fabiankeil.de> (earlier version)
MFC after:	3 days
2012-06-29 07:35:37 +00:00
George V. Neville-Neil
4737d389b0 Integrate a fix for a very odd signal delivery problem found
by Bryan Cantril and others in the Solaris/Illumos version of DTrace.

Obtained from: https://www.illumos.org/issues/789
MFC after:	2 weeks
2012-06-04 16:15:40 +00:00
Zachary Loafman
db5c7d363d Fix DTrace TSC skew calculation:
The skew calculation here is exactly backwards. We were able to repro
it on a multi-package ESX server running a FreeBSD VM, where the TSCs
can be pretty evil.

MFC after: 1 week

Submitted by: Jeff Ford <jeffrey.ford2@isilon.com>
Reviewed by: avg, gnn
2012-06-04 16:04:01 +00:00
Ryan Stone
9742410797 Instead of only iterating over the set of known SDT probes when sdt.ko is
loaded and unloaded, also have sdt.ko register callbacks with kern_sdt.c
that will be called when a newly loaded KLD module adds more probes or
a module with probes is unloaded.

This fixes two issues: first, if a module with SDT probes was loaded after
sdt.ko was loaded, those new probes would not be available in DTrace.
Second, if a module with SDT probes was unloaded while sdt.ko was loaded,
the kernel would panic the next time DTrace had cause to try and do
anything with the no-longer-existent probes.

This makes it possible to create SDT probes in KLD modules, although there
are still two caveats: first, any SDT probes in a KLD module must be part
of a DTrace provider that is defined in that module.  At present DTrace
only destroys probes when the provider is destroyed, so you can still
panic the system if a KLD module creates new probes in a provider from a
different module(including the kernel) and then unload the the first module.

Second, the system will panic if you unload a module containing SDT probes
while there is an active D script that has enabled those probes.

MFC after:	1 month
2012-03-27 15:07:43 +00:00
Oleksandr Tymoshenko
683822338e - For o32 ABI get arguments from the stack
- Clear CPU_DTRACE_FAULT flag in userland backtrace routine. It just
   means we hit wrong memory region and should stop.
2012-03-26 21:47:06 +00:00
Oleksandr Tymoshenko
933fab9d73 Properly cast 64-bit dofhp_dof to pointer.
For i386 this change is no-op. For AMD64 it was tested with DTrace test
suite: results are the same from the test run before the change and after
2012-03-26 21:22:51 +00:00
Oleksandr Tymoshenko
4d18d83736 Use macroses to load/store pointers and increase indexes instead of
hardcoded MIPS64 instructions
2012-03-26 01:26:33 +00:00
Oleksandr Tymoshenko
c57e9d4e83 Add device part of DTrace/MIPS code 2012-03-24 05:14:37 +00:00