former return the current status for the latter to use. Without this we
could enable interrupts when they shouldn't be.
It's still not quite right as it should only update the bits we care about,
bit should be good enough until the correct fix can be tested.
PR: 204270
Obtained from: ABT Systems Ltd
Sponsored by: The FreeBSD Foundation
Currently, Application Processors (non-boot CPUs) are started by
MD code at SI_SUB_CPU, but they are kept waiting in a "pen" until
SI_SUB_SMP at which point they are released to run kernel threads.
SI_SUB_SMP is one of the last SYSINIT levels, so APs don't enter
the scheduler and start running threads until fairly late in the
boot.
This change moves SI_SUB_SMP up to just before software interrupt
threads are created allowing the APs to start executing kernel
threads much sooner (before any devices are probed). This allows
several initialization routines that need to perform initialization
on all CPUs to now perform that initialization in one step rather
than having to defer the AP initialization to a second SYSINIT run
at SI_SUB_SMP. It also permits all CPUs to be available for
handling interrupts before any devices are probed.
This last feature fixes a problem on with interrupt vector exhaustion.
Specifically, in the old model all device interrupts were routed
onto the boot CPU during boot. Later after the APs were released at
SI_SUB_SMP, interrupts were redistributed across all CPUs.
However, several drivers for multiqueue hardware allocate N interrupts
per CPU in the system. In a system with many CPUs, just a few drivers
doing this could exhaust the available pool of interrupt vectors on
the boot CPU as each driver was allocating N * mp_ncpu vectors on the
boot CPU. Now, drivers will allocate interrupts on their desired CPUs
during boot meaning that only N interrupts are allocated from the boot
CPU instead of N * mp_ncpu.
Some other bits of code can also be simplified as smp_started is
now true much earlier and will now always be true for these bits of
code. This removes the need to treat the single-CPU boot environment
as a special case.
As a transition aid, the new behavior is available under a new kernel
option (EARLY_AP_STARTUP). This will allow the option to be turned off
if need be during initial testing. I plan to enable this on x86 by
default in a followup commit in the next few days and to have all
platforms moved over before 11.0. Once the transition is complete,
the option will be removed along with the !EARLY_AP_STARTUP code.
These changes have only been tested on x86. Other platform maintainers
are encouraged to port their architectures over as well. The main
things to check for are any uses of smp_started in MD code that can be
simplified and SI_SUB_SMP SYSINITs in MD code that can be removed in
the EARLY_AP_STARTUP case (e.g. the interrupt shuffling).
PR: kern/199321
Reviewed by: markj, gnn, kib
Sponsored by: Netflix
When this flag is turned on, DOF and DIF validation errors are printed to
the kernel message buffer. This is useful for debugging.
Also remove the debug.dtrace.debug sysctl, which has no effect.
While the instructions were not included into the original instruction
set, their support can be indicated by a special feature bit.
For example:
CPU: AMD Phenom(tm) II X4 955 Processor (3214.71-MHz K8-class CPU)
...
AMD Features2=0x37ff<LAHF, ...>
Clang 3.8 uses lahf/sahf as a faster alternative to pushf/popf where
possible.
MFC after: 2 weeks
Currently this argument is a pointer into the stack which is used by FBT
to fetch the first five probe arguments. On all non-x86 architectures it's
simply the trapframe address, so this change has no functional impact. On
amd64 it's a pointer into the trapframe such that stack[1 .. 5] gives the
first five argument registers, which are deliberately grouped together in
the amd64 trapframe definition.
A trapframe argument simplifies the invop handlers on !x86 and makes the
x86 FBT invop handler easier to understand. Moreover, it allows for invop
handlers that may want to modify the register set of the interrupted thread.
This allows the hrtimer to be used earlier during boot. This is required
for boot-time DTrace: anonymous enablings are created during
SI_SUB_DTRACE_ANON, which runs before APs are started. In particular,
the DTrace deadman timer requires that the hrtimer be functional.
MFC after: 2 weeks
Allow using DTRACE for performance analysis of userspace
applications - the function call stack can be captured.
This is almost an exact copy of AMD64 solution.
Obtained from: Semihalf
Sponsored by: Cavium
Reviewed by: emaste, gnn, jhibbits
Differential Revision: https://reviews.freebsd.org/D5779
- Handle the case where no DOF helper is provided. This occurs with the
currently-unused DTRACEHIOC_ADD ioctl.
- Fix some checks that prevented the loading DOF in the (non-default)
lazyload mode.
need to include it explicitly when <vm/vm_param.h> is already included.
Suggested by: alc
Reviewed by: alc
Differential Revision: https://reviews.freebsd.org/D5379
Rather than pushing all eight possible arguments into dtrace_probe()'s
stack frame, make the syscall_args struct for the current syscall available
via the current thread. Using a custom getargval method for the systrace
provider, this allows any syscall argument to be fetched, even in kernels
that have modified the maximum number of system call arguments.
Sponsored by: EMC / Isilon Storage Division
r281257 added support for lazyload mode by allowing dtrace(1) to register
a DOF section on behalf of a traced process. This was implemented by
having libdtrace copy the DOF section into a heap-allocated buffer and
passing its address to the ioctl handler. However, DTrace uses the DOF
section address as a lookup key in certain cases, so the ioctl handler
should be given the target process' DOF section address instead. This
change modifies the ADDDOF handler to copy the DOF section in from the
target process, rather than from dtrace(1).
stack, take into account the copy of rsi pushed between the breakpoint
trapframe and the dtrace_invop frame. Prior to r287644, this was covered
by the fact that sizeof(struct amd64_frame) was 24 rather than 16.
Reported by: smh
since on amd64 the first argument to a function is generally not on the
stack.
Revert an old DTrace bug fix to some code that assumed that
sizeof(struct amd64_frame) == 16.
Reviewed by: jhb, kib
Sponsored by: EMC / Isilon Storage Division
Differential Revision: https://reviews.freebsd.org/D3255
belongs to the kernel stack address range for the thread. Right now,
code checks that new frame is not farther then KSTACK_PAGES pages from
the current frame, which allows the address to point past the top of
the stack.
Reviewed by: andrew, emaste, markj
Differential revision: https://reviews.freebsd.org/D3108
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
macros on amd64 and i386. Move the definition to machine/param.h.
kgdb defines INKERNEL() too, the conflict is resolved by renaming kgdb
version to PINKERNEL().
On i386, correct the lowest kernel address. After the shared page was
introduced, USRSTACK no longer points to the last user address + 1 [*]
Submitted by: Oliver Pinter [*]
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
It would previously call into some unfinished Solaris compatibility code and
return without actually calling panic(9). The compatibility code is
unneeded, however, so just remove it and have dtrace_panic() call vpanic(9)
directly.
Differential Revision: https://reviews.freebsd.org/D2349
Reviewed by: avg
MFC after: 2 weeks
Sponsored by: EMC / Isilon Storage Division
Passing "-x lazyload" to dtrace -G during compilation causes dtrace(1) to
not link drti.o into the output object file, so the USDT probes are not created
during process startup. Instead, dtrace(1) will automatically discover and
create probes on the process' behalf when attaching.
Differential Revision: https://reviews.freebsd.org/D2203
Reviewed by: rpaulo
MFC after: 1 month
This adds an upper bound, dtrace_ustackdepth_max, to the number of frames
traversed when computing the userland stack depth. Some programs - notably
firefox - are otherwise able to trigger an infinite loop in
dtrace_getustack_common(), causing a panic.
MFC after: 1 week
traps do appear in the regular call stack, rather than only in a special
trap frame, so we don't need to inject the trap-frame $pc into a returned
stack trace in DTrace.
MFC after: 3 days
Sponsored by: DARPA, AFRL
emulate the instructions used in function entry and exit.
For function entry ARM will use a push instruction to push up to 16
registers to the stack. While we don't expect all 16 to be used we need to
handle any combination the compiler may generate, even if it doesn't make
sense (e.g. pushing the program counter).
On function return we will either have a pop or branch instruction. The
former is similar to the push instruction, but with care to make sure we
update the stack pointer and program counter correctly in the cases they
are either in the list of registers or not. For branch we need to take the
24-bit offset, sign-extend it, and add that number of 4-byte words to the
program counter. Care needs to be taken as, due to historical reasons, the
address the branch is relative to is not the current instruction, but 8
bytes later.
This allows us to use the following probes on ARM boards:
dtrace -n 'fbt::malloc:entry { stack() }'
and
dtrace -n 'fbt:🆓return { stack() }'
Differential Revision: https://reviews.freebsd.org/D2007
Reviewed by: gnn, rpaulo
Sponsored by: ABT Systems Ltd
expected to return the data in the memory location pointed at by target
after the operation. The FreeBSD atomic functions previously used return
either 0 or 1 to indicate if the comparison succeeded or not respectively.
With this change these functions only support ARMv6 and later are supported
by these functions.
Sponsored by: ABT Systems Ltd
dtrace is able to display a stack trace similar to the one below.
# dtrace -p 603 -n 'tcp:kernel::receive { stack(); }'
0 70 :receive
kernel`ip_input+0x140
kernel`netisr_dispatch_src+0xb8
kernel`ether_demux+0x1c4
kernel`ether_nh_input+0x3a8
kernel`netisr_dispatch_src+0xb8
kernel`ether_input+0x60
kernel`cpsw_intr_rx+0xac
kernel`intr_event_execute_handlers+0x128
kernel`ithread_loop+0xb4
kernel`fork_exit+0x84
kernel`swi_exit
kernel`swi_exit
Tested by: gnn
Sponsored by: ABT Systems Ltd
Since the upstream for cddl code is now illumos not sun, mechanically
convert all sun #ifdef's to illumos #ifdef's which have been used in all
newer code for some time.
Also do a manual pass to correct the use if #ifdef comments as per style(9)
as well as few uses of #if defined(__FreeBSD__) vs #ifndef illumos.
MFC after: 1 month
Sponsored by: Multiplay
It's redundant at the moment since it can be obtained from the trapframe
on the architectures where DTrace is supported, but this won't be the case
with ARM.
- Wrong integer type was specified.
- Wrong or missing "access" specifier. The "access" specifier
sometimes included the SYSCTL type, which it should not, except for
procedural SYSCTL nodes.
- Logical OR where binary OR was expected.
- Properly assert the "access" argument passed to all SYSCTL macros,
using the CTASSERT macro. This applies to both static- and dynamically
created SYSCTLs.
- Properly assert the the data type for both static and dynamic
SYSCTLs. In the case of static SYSCTLs we only assert that the data
pointed to by the SYSCTL data pointer has the correct size, hence
there is no easy way to assert types in the C language outside a
C-function.
- Rewrote some code which doesn't pass a constant "access" specifier
when creating dynamic SYSCTL nodes, which is now a requirement.
- Updated "EXAMPLES" section in SYSCTL manual page.
MFC after: 3 days
Sponsored by: Mellanox Technologies
Summary:
Fix the stack tracing for dtrace/powerpc by using the trapexit/asttrapexit
return address sentinels instead of checking within the kernel address space.
As part of this, I had to add new inline functions. FBT traces the kernel, so
we have to have special case handling for this, since a trap will create a full
new trap frame, and there's no way to pass around the 'real' stack. I handle
this by special-casing 'aframes == 0' with the trap frame. If aframes counts
out to the trap frame, then assume we're looking for the full kernel trap frame,
so switch to the real stack pointer.
Test Plan: Tested on powerpc64
Reviewers: rpaulo, markj, nwhitehorn
Reviewed By: markj, nwhitehorn
Differential Revision: https://reviews.freebsd.org/D788
MFC after: 3 week
Relnotes: Yes
the upstream implementation and helps ensure that a trap induced by tracing
fbt::trap:entry is handled without recursively generating another trap.
This makes it possible to run most (but not all) of the DTrace tests under
common/safety/ without triggering a kernel panic.
Submitted by: Anton Rang <anton.rang@isilon.com> (original version)
Phabric: D95
These changes prevent sysctl(8) from returning proper output,
such as:
1) no output from sysctl(8)
2) erroneously returning ENOMEM with tools like truss(1)
or uname(1)
truss: can not get etype: Cannot allocate memory
there is an environment variable which shall initialize the SYSCTL
during early boot. This works for all SYSCTL types both statically and
dynamically created ones, except for the SYSCTL NODE type and SYSCTLs
which belong to VNETs. A new flag, CTLFLAG_NOFETCH, has been added to
be used in the case a tunable sysctl has a custom initialisation
function allowing the sysctl to still be marked as a tunable. The
kernel SYSCTL API is mostly the same, with a few exceptions for some
special operations like iterating childrens of a static/extern SYSCTL
node. This operation should probably be made into a factored out
common macro, hence some device drivers use this. The reason for
changing the SYSCTL API was the need for a SYSCTL parent OID pointer
and not only the SYSCTL parent OID list pointer in order to quickly
generate the sysctl path. The motivation behind this patch is to avoid
parameter loading cludges inside the OFED driver subsystem. Instead of
adding special code to the OFED driver subsystem to post-load tunables
into dynamically created sysctls, we generalize this in the kernel.
Other changes:
- Corrected a possibly incorrect sysctl name from "hw.cbb.intr_mask"
to "hw.pcic.intr_mask".
- Removed redundant TUNABLE statements throughout the kernel.
- Some minor code rewrites in connection to removing not needed
TUNABLE statements.
- Added a missing SYSCTL_DECL().
- Wrapped two very long lines.
- Avoid malloc()/free() inside sysctl string handling, in case it is
called to initialize a sysctl from a tunable, hence malloc()/free() is
not ready when sysctls from the sysctl dataset are registered.
- Bumped FreeBSD version to indicate SYSCTL API change.
MFC after: 2 weeks
Sponsored by: Mellanox Technologies
2915 DTrace in a zone should see "cpu", "curpsinfo", et al
2916 DTrace in a zone should be able to access fds[]
2917 DTrace in a zone should have limited provider access
MFC after: 2 weeks
usage from dtrace. The dtrace code already uses cdevpriv(9) since FreeBSD
8, so this change should be quite harmless.
Reviewed by: markj
Approved by: markj
MFC after: never
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
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
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
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
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
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
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
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
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
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
certain instructions in a function prologue or epilogue. DTrace has a
hook into the invalid opcode fault handler that checks whether the fault
was due to an probe and if so, runs the DTrace magic.
Upon returning from an invalid opcode fault caused by a probe, DTrace must
emulate the instruction that was replaced with the invalid opcode and then
return control to the instruction following the invalid opcode.
There were a pair of related bugs in the emulation for the leave
instruction. The leave instruction is used to pop off a stack frame prior
to returning from a function. The emulation for this instruction must
move the trap frame for the invalid opcode fault down the stack to the
bottom of the stack frame that is being removed, and then execute an iret.
At two points in this process, the emulation code was storing values above
the current value of the stack pointer. This opened up a window in which
if we were two take an interrupt, the trap frame for the interrupt would
overwrite the values stored on the stack, causing the system to panic
later.
The first bug was that at one point the emulation code saves the new value
for $esp above the current stack pointer value. The fix is to save this
value instead inside of the original trap frame. At this point we do
not need the original trap frame so this is safe.
The second bug is that when the emulate code loads $esp from the stack, it
points part-way through the new trap frame instead of at its beginning.
The emulation code adjusts the stack pointer to the correct value
immediately afterwards, but this still leaves a one instruction window in
which an interrupt would corrupt this trap frame. Fix this by adjusting
the stack frame value before loading it into $esp.
This fixes panics in invop_leave on i386 when using fbt return probes.
Reviewed by: rpaulo, attilio
MFC after: 1 week
