the 4 byte-aligned dtrace_invop_callsite can be found and that it
immediately follows the call to dtrace_invop(). Secondly, fix some pointer
arithmetic to account for differences between struct i386_frame and illumos'
struct frame. Finally, ensure that dtrace_getarg() isn't inlined. It works
by following a fixed number of frame pointers to the probe site, so inlining
breaks it.
MFC after: 3 weeks
first five for probes entered through a UD fault (i.e. FBT probes).
Specifically, handle the fact that dtrace_invop_callsite must be
16 byte-aligned and thus may not immediately follow the call to
dtrace_invop() in dtrace_invop_start(). Also fetch register arguments and
the stack pointer through a struct trapframe instead of a struct reg.
PR: 191260
Submitted by: luke.tw@gmail.com
MFC after: 3 weeks
defined. This ensures that the sdt:zfs:: probes appear despite the fact
the sdt provider is defined in the kernel rather than in zfs.ko.
Reported by: hiren
Tested by: hiren
MFC after: 2 weeks
This includes decodes of recent Intel instructions, in particular
VT-x and related instructions. This allows the FBT provider to
locate the exit points of routines that include these new
instructions.
Illumos issues:
3414 Need a new word of AT_SUN_HWCAP bits
3415 Add isainfo support for f16c and rdrand
3416 Need disassembler support for rdrand and f16c
3413 isainfo -v overflows 80 columns
3417 mdb disassembler confuses rdtscp for invlpg
1518 dis should support AMD SVM/AMD-V/Pacifica instructions
1096 i386 disassembler should understand complex nops
1362 add kvmstat for monitoring of KVM statistics
1363 add vmregs[] variable to DTrace
1364 need disassembler support for VMX instructions
1365 mdb needs 16-bit disassembler support
This corresponds to Illumos-gate (github) version
eb23829ff08a873c612ac45d191d559394b4b408
Reviewed by: markj
MFC after: 1 week
sites and installing a hook at the kernel's trap handler. The fasttrap code
will emulate the overwritten instruction in some common cases, but otherwise
copies it out into some scratch space in the traced process' address space
and ensures that it's executed after returning from the trap.
In Solaris and illumos, this (per-thread) scratch space comes from some
reserved space in TLS, accessible via the fs segment register. This
approach is somewhat unappealing on FreeBSD since it would require some
modifications to rtld and jemalloc (for static TLS) to ensure that TLS is
executable, and would thus introduce dependencies on their implementation
details. I think it would also be impossible to safely trace static binaries
compiled without these modifications.
This change implements the functionality in a different way, by having
fasttrap map pages into the target process' address space on demand. Each
page is divided into 64-byte chunks for use by individual threads, and
fasttrap's process descriptor struct has been extended to keep track of
any scratch space allocated for the corresponding process.
With this change it's possible to trace all libc functions in a program,
e.g. with
pid$target:libc.so.*::entry {@[probefunc] = count();}
Previously this would generally cause the victim process to crash, as
tracing memcpy on amd64 requires the functionality described above.
Tested by: Prashanth Kumar <pra_udupi@yahoo.co.in> (earlier version)
MFC after: 6 weeks
that this is done for SDT probes. This fixes the syscall/tst.args.d test,
which was failing because mmap(2)'s sixth argument wasn't available to the
probe.
MFC after: 2 weeks
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>
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
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
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
* 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().
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
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
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
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
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
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
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
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
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
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
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
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.
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
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
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.
- 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
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
