Commit Graph

246 Commits

Author SHA1 Message Date
markj
706ad3a3fd Clear systrace_args_func when systrace probes are disabled.
This function pointer is invalidated when systrace.ko is unloaded.

Reported by:	pho
MFC after:	1 week
Sponsored by:	The FreeBSD Foundation
2020-02-28 17:04:36 +00:00
kaktus
ad355b0a9d Mark more nodes as CTLFLAG_MPSAFE or CTLFLAG_NEEDGIANT (17 of many)
r357614 added CTLFLAG_NEEDGIANT to make it easier to find nodes that are
still not MPSAFE (or already are but aren’t properly marked).
Use it in preparation for a general review of all nodes.

This is non-functional change that adds annotations to SYSCTL_NODE and
SYSCTL_PROC nodes using one of the soon-to-be-required flags.

Mark all obvious cases as MPSAFE.  All entries that haven't been marked
as MPSAFE before are by default marked as NEEDGIANT

Approved by:	kib (mentor, blanket)
Commented by:	kib, gallatin, melifaro
Differential Revision:	https://reviews.freebsd.org/D23718
2020-02-26 14:26:36 +00:00
mjg
3bd5f540e5 dtrace: add missing CLTFLAG_MPSAFE annotations 2020-01-12 04:53:22 +00:00
ian
1090e6574b Remove scary-looking printf output that happens when you kldload dtrace on
arm.  Replace it with a comment block explaining why the function is empty
on 32-bit arm.
2020-01-09 22:51:37 +00:00
oshogbo
8f5f92bd8e dtrace: 64-bits registers support
The registers in ilumos and FreeBSD have a different number.
In the illumos, last 32-bits register defined is SS an in FreeBSD is GS.
While translating register we should comper it to the highest one.

PR:             240358
Reported by:    lwhsu@
MFC after:      2 weeks
2019-10-04 16:17:00 +00:00
markj
d40f328517 Implement x86 dtrace_invop_(un)init() in C.
There is no reason for these routines to be written in assembly.  In
the ports of DTrace to other platforms, they are already written in C.
No functional change intended.

MFC after:	1 week
Sponsored by:	Netflix
2019-09-23 15:08:17 +00:00
oshogbo
a4e74e9ba6 dtrace: 64-bits registers support
The registers in ilumos and FreeBSD have a different number.
In the illumos, last 32-bits register defined is SS an in FreeBSD is GS.
This off-by-one caused the uregs array to returns the wrong 64-bits register
on amd64.

Reviewed by:	markj
MFC after:	2 weeks
Differential Revision:	https://reviews.freebsd.org/D20363
2019-06-05 22:29:05 +00:00
jhibbits
f1e6763048 powerpc/dtrace: Fix fbt function probing for ELFv2
'.' function names exist only in ELFv1.  ELFv2 does away with function
descriptors, and look more like they do on powerpc(32) and most other
platforms, as direct function pointers.  Stop blacklisting regular function
names in ELFv2.

Submitted by:	Brandon Bergren
Differential Revision:	https://reviews.freebsd.org/D20346
2019-05-27 03:18:56 +00:00
jhibbits
2635d6002e powerpc/dtrace: Actually fix stack traces
Fix stack unwinding such that requesting N stack frames in lockstat will
actually give you N frames, not anywhere from 0-3 as had been before.

lockstat prints the mutex function instead of the caller as the reported
locker, but the stack frame is detailed enough to find the real caller.

MFC after:	2 weeks
2019-05-17 19:57:08 +00:00
kib
653b035c89 Remove resolver_qual from DEFINE_IFUNC/DEFINE_UIFUNC macros.
In all practical situations, the resolver visibility is static.

Requested by:	markj
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
Approved by:	so (emaste)
Differential revision:	https://reviews.freebsd.org/D20281
2019-05-16 22:20:54 +00:00
jhibbits
81013cfae7 powerpc/dtrace: Fix dtrace powerpc asm, and simplify stack walking
Fix some execution bugs in the dtrace powerpc asm.  addme pulls in the carry
flag which we don't want, and the result wasn't recorded anyways, so the
following beq to check for exit condition wasn't checking the right
condition.

Simplify the stack walking in dtrace_isa.c, so there's only a single walker
that handles both pc and sp.  This should make it easier to follow, and any
bugfix that may be needed for walking only needs to be made in one place
instead of two now.

MFC after:	2 weeks
2019-04-13 03:32:21 +00:00
markj
1cd6073f58 Use an explicit comparison with VM_GUEST_NO.
Reported by:	jhb
MFC with:	r345359
Sponsored by:	The FreeBSD Foundation
2019-03-21 20:07:50 +00:00
markj
52ae896ad7 Don't attempt to measure TSC skew when running as a VM guest.
It simply doesn't work in general since VCPUs may migrate between
physical cores.  The approach used to measure skew also doesn't
make much sense in a VM.

PR:		218452
MFC after:	2 weeks
Sponsored by:	The FreeBSD Foundation
2019-03-21 02:52:22 +00:00
markj
57c4e2d807 Fix a tracepoint lookup race in fasttrap_pid_probe().
fasttrap hooks the userspace breakpoint handler; the hook looks up the
breakpoint address in a hash table of tracepoints.  It is possible for
the tracepoint to be removed by a different thread in between the
breakpoint trap and the hash table lookup, in which case SIGTRAP gets
delivered to the target process.  Fix the problem by adding a
per-process generation counter that gets incremented when a tracepoint
belonging to that process is removed.  Then, when a lookup fails, the
trapping instruction is restarted if the thread's counter doesn't match
that of the process.

Reviewed by:	cem
MFC after:	2 weeks
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D19273
2019-02-21 22:54:17 +00:00
mjg
a2507cdb8a dtrace: fix userspace access on boxes with SMAP
dtrace has its own routines which were not updated after SMAP support got
implemented. Use ifunc just like for other routines.

This in particular fixes ustack().

Reviewed by:	markj
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D18542
2018-12-13 20:09:38 +00:00
jhibbits
fa1f71dac0 DTrace/powerpc: Fix FBT return probes
The FBT fuction boundary prober was setting one return probe marker value,
but the dtrace handler was expecting another.  This causes a hang when
tracing return probes.
2018-11-21 16:47:11 +00:00
jhibbits
ffc1dda83c powerpc/dtrace: Use explicit bit numbers to mask out PSL_EE
There seems to be a race in CI, such that dtrace_asm.S might be assembled
before the genassym is completed.  This causes a build failure when PSL_EE
doesn't exist, and is read as 0.  Get around this by explicitly specifying
the bits in the mask instead.
2018-10-21 02:08:57 +00:00
jhb
c741b8babc Various fixes for TLB management on RISC-V.
- Remove the arm64-specific cpu_*cache* and cpu_tlb_flush* functions.
  Instead, add RISC-V specific inline functions in cpufunc.h for the
  fence.i and sfence.vma instructions.
- Catch up to changes in the arm64 pmap and remove all the cpu_dcache_*
  calls, pmap_is_current, pmap_l3_valid_cacheable, and PTE_NEXT bits from
  pmap.
- Remove references to the unimplemented riscv_setttb().
- Remove unused cpu_nullop.
- Add a link to the SBI doc to sbi.h.
- Add support for a 4th argument in SBI calls.  It's not documented but
  it seems implied for the asid argument to SBI_REMOVE_SFENCE_VMA_ASID.
- Pass the arguments from sbi_remote_sfence*() to the SEE.  BBL ignores
  them so this is just cosmetic.
- Flush icaches on other CPUs when they resume from kdb in case the
  debugger wrote any breakpoints while the CPUs were paused in the IPI_STOP
  handler.
- Add SMP vs UP versions of pmap_invalidate_* similar to amd64.  The
  UP versions just use simple fences.  The SMP versions use the
  sbi_remove_sfence*() functions to perform TLB shootdowns.  Since we
  don't have a valid pm_active field in the riscv pmap, just IPI all
  CPUs for all invalidations for now.
- Remove an extraneous TLB flush from the end of pmap_bootstrap().
- Don't do a TLB flush when writing new mappings in pmap_enter(), only if
  modifying an existing mapping.  Note that for COW faults a TLB flush is
  only performed after explicitly clearing the old mapping as is done in
  other pmaps.
- Sync the i-cache on all harts before updating the PTE for executable
  mappings in pmap_enter and pmap_enter_quick.  Previously the i-cache was
  only sync'd after updating the PTE in pmap_enter.
- Use sbi_remote_fence() instead of smp_rendezvous in pmap_sync_icache().

Reviewed by:	markj
Approved by:	re (gjb, kib)
Sponsored by:	DARPA
Differential Revision:	https://reviews.freebsd.org/D17414
2018-10-15 18:56:54 +00:00
br
639c5f49ef Add support for 'C'-compressed ISA extension to DTrace FBT provider.
Approved by:	re (kib)
Sponsored by:	DARPA, AFRL
2018-09-03 14:34:09 +00:00
markj
0f81d204ed Fix the hash table lookup in fbt_destroy().
Reported and tested by:	pho
Approved by:	re (kib)
X-MFC with:	r338359
2018-09-02 17:02:13 +00:00
markj
651480fae0 Allow multiple FBT probes to share a tracepoint.
With GNU ifuncs, multiple FBT probes may correspond to the same
instruction.  fbt_invop() assumed that this could not happen and
would return after the first probe found in the global FBT hash
table, which might not be the one that's enabled.  Fix the problem
on x86 by linking probes that share a tracepoint and having each
linked probe fire when the tracepoint is hit.

PR:		230846
Approved by:	re (gjb)
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D16921
2018-08-28 20:21:36 +00:00
jhibbits
c959497ef5 dtrace/powerpc: Correct register indices for non-indexed registers in the trapframe
Fix an off-by-one error, LR starts at index 32, not index 33, and the others
follow suit.
2018-07-16 19:47:29 +00:00
jhibbits
45332e3d1f Revert r326083, it doesn't behave as expected.
Even though there do appear to be more artificial frames, with 12, stack
traces no longer list at all.  Revert until a better, more stable value can
be determined.
2018-06-03 03:53:11 +00:00
jhibbits
c0a10a2d85 Protect dtrace_getpcstack() from a NULL stack pointer in a trap frame
Found when trying to use lockstat on a POWER9, the stack pointer (r1) could
be NULL, and result in a NULL pointer dereference, crashing the kernel.
2018-05-30 03:48:27 +00:00
markj
225f18443a DTrace aarch64: Avoid calling unwind_frame() in the probe context.
unwind_frame() may be instrumented by FBT, leading to recursion into
dtrace_probe(). Manually inline unwind_frame() as we do with stack
unwinding code for other architectures.

Submitted by:	Domagoj Stolfa
Reviewed by:	manu
MFC after:	1 week
Sponsored by:	DARPA / AFRL
Differential Revision:	https://reviews.freebsd.org/D15359
2018-05-12 15:35:26 +00:00
mjg
a38d172e95 systrace: track it like sdt probes
While here predict false.

Note the code is wrong (regardless of this change). Dereference of the
pointer can race with module unload. A fix would set the probe to a
nop stub instead of NULL.
2018-04-27 15:16:34 +00:00
mjg
5c3b76a7ee dtrace: depessimize dtmalloc when dtrace is active
Each malloc/free was testing dtrace_malloc_enabled and forcing
extra reads from the malloc type struct to see if perhaps a
dtmalloc probe was on.

Treat it like lockstat and sdt: have a global bolean.
2018-04-24 01:06:20 +00:00
mjg
a7bb12777a lockstat: track lockstat just like sdt probes
In particular flip the frequently tested var to bool.
2018-04-24 01:04:10 +00:00
markj
59b1fdfb3d Assert that dtrace_probe() doesn't re-enter itself.
This helps catch cases where an instrumented function is called while
in probe context.

Submitted by:	Domagoj Stolfa <domagoj.stolfa@gmail.com>
MFC after:	2 weeks
Sponsored by:	DARPA/AFRL
Differential Revision:	https://reviews.freebsd.org/D14863
2018-04-10 13:47:09 +00:00
jhb
24fa2df20b Remove very old and unused signal information codes.
These have been supplanted by the MI signal information codes in
<sys/signal.h> since 7.0.  The FPE_*_TRAP ones were deprecated even
earlier in 1999.

PR:		226579 (exp-run)
Reviewed by:	kib
Differential Revision:	https://reviews.freebsd.org/D14637
2018-03-27 20:57:51 +00:00
markj
5f265d26d1 Revert part of r331264: disable interrupts before disabling WP.
We might otherwise be preempted, leaving WP disabled while another
thread runs on the CPU.

Reported by:	kib
X-MFC with:	r331264
2018-03-20 21:36:35 +00:00
markj
5ea8c6620a Make use of the KPI added in r331252.
MFC after:	2 weeks
2018-03-20 21:16:26 +00:00
emaste
6fe54a5343 Rename assym.s to assym.inc
assym is only to be included by other .s files, and should never
actually be assembled by itself.

Reviewed by:	imp, bdrewery (earlier)
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D14180
2018-03-20 17:58:51 +00:00
markj
9d45d000b2 Unbreak amd64 FBT after r330539.
X-MFC with:	r330539
2018-03-06 15:51:59 +00:00
markj
c4bc9a29b5 Avoid CPU migration in dtrace_gethrtime() on x86.
dtrace_gethrtime() may be called outside of probe context, and in
particular, from the DTRACEIOC_BUFSNAP handler.

Disable interrupts rather than using sched_pin() to help ensure that
we don't call any external functions when in probe context.

PR:		218452
MFC after:	1 week
2017-12-18 17:26:24 +00:00
markj
507cb204bf Don't use pcpu_find() to determine if a CPU ID is valid.
This addresses assertion failures after r326218.

MFC after:	1 week
2017-11-27 18:42:23 +00:00
jhibbits
ba5835b241 PowerPC has 12 artificial frames for the profiler
It may need to be different between AIM and Book-E, this was tested only on
Book-E (64- and 32-bit)

MFC after:	3 weeks
2017-11-22 01:53:59 +00:00
mjg
a5920c64e5 sdt: make all sdt probe sites test one variable
This saves on cache misses at the expense of a slight grow of .text.

Note this is a bandaid for lack of hotpatching.

Discussed with:	markj
2017-10-22 20:22:23 +00:00
markj
ae879c6393 Use C99 initializers for DTrace provider methods.
This makes the definitions easier to read and more cscope-friendly.

MFC after:	1 week
2017-09-27 17:46:38 +00:00
lidl
9290d460ca Enable dtrace support for mips64 and the ERL kernel config
Turn on the required options in the ERL config file, and ensure
that the fbt module is listed as a dependency for mips in
the modules/dtrace/dtraceall/dtraceall.c file.

PR: 		220346
Reviewed by:	gnn, markj
MFC after:	2 weeks
Differential Revision:	https://reviews.freebsd.org/D12227
2017-09-06 03:19:52 +00:00
br
3364e8aea9 o Replace __riscv__ with __riscv
o Replace __riscv64 with (__riscv && __riscv_xlen == 64)

This is required to support new GCC 7.1 compiler.
This is compatible with current GCC 6.1 compiler.

RISC-V is extensible ISA and the idea here is to have built-in define
per each extension, so together with __riscv we will have some subset
of these as well (depending on -march string passed to compiler):

__riscv_compressed
__riscv_atomic
__riscv_mul
__riscv_div
__riscv_muldiv
__riscv_fdiv
__riscv_fsqrt
__riscv_float_abi_soft
__riscv_float_abi_single
__riscv_float_abi_double
__riscv_cmodel_medlow
__riscv_cmodel_medany
__riscv_cmodel_pic
__riscv_xlen

Reviewed by:	ngie
Sponsored by:	DARPA, AFRL
Differential Revision:	https://reviews.freebsd.org/D11901
2017-08-07 14:09:57 +00:00
jhibbits
11138abae1 Follow up r313841 on powerpc
Close a potential race in reading the CPU dtrace flags, where a thread can
start on one CPU, and partway through retrieving the flags be swapped out,
while another thread traps and sets the CPU_DTRACE_NOFAULT.  This could
cause the first thread to return without handling the fault.

Discussed with:	markj@
2017-06-09 20:26:42 +00:00
markj
496d8116b2 Ensure that profile and tick probes provide a non-zero PC value.
The idle thread may process callouts while reloading the timer in
cpu_activeclock(). In this case, provide a representative value, &cpu_idle,
instead of 0 for args[0] so that the active thread can be more easily
identified from the probe.

This addresses intermittent failures of the profile-n/tst.argtest.d test.

MFC after:	2 weeks
Sponsored by:	Dell EMC Isilon
Differential Revision:	https://reviews.freebsd.org/D10651
2017-05-15 21:44:40 +00:00
jhibbits
fe778c6778 Fix stack tracing in dtrace for powerpc
The current method only sort of works, and usually doesn't work reliably.
Also, on Book-E the return address from DEBUG exceptions is not the sentinel
addresses, so it won't exit the loop correctly.

Fix this by better handling trap frames during unwinding, and using the
common trap handler for debug traps, as the code in that segment is
identical between the two.

MFC after:	1 week
2017-05-11 00:23:51 +00:00
jhibbits
68f8afc40a Fix the encoded instruction for FBT traps on powerpc
r314370 changed EXC_DTRACE to a different instruction, but neglected to
make the same change to fbt, so dtrace didn't actually pick it up,
resulting in entering KDB instead of trapping for dtrace.

MFC after:	1 week
2017-05-10 03:47:22 +00:00
jhibbits
263941565c Fix check for fbt_excluded() in powerpc
fbt_excluded() returns 1 if the symbol is to be excluded.  Every other
arch has this correct, powerpc was the only broken one

MFC after:	1 week
2017-05-10 03:20:20 +00:00
markj
6614769ca7 Fix a harmless LOR in dtrace_load().
MFC after:	1 week
2017-05-01 17:01:00 +00:00
pkelsey
33064e92a2 Corrected misspelled versions of rendezvous.
The MFC will include a compat definition of smp_no_rendevous_barrier()
that calls smp_no_rendezvous_barrier().

Reviewed by:	gnn, kib
MFC after:	1 week
Differential Revision:	https://reviews.freebsd.org/D10313
2017-04-09 02:00:03 +00:00
markj
ad3b99aa30 Fix a backwards comparison in the code to dump a DTrace debug buffer.
PR:		217739
MFC after:	1 week
2017-03-13 18:43:00 +00:00
markj
b12a88ae0f Directly include needed headers rather than relying on pollution.
We get machine/cpu.h via kmem.h -> proc.h -> _vm_domain.h -> seq.h.

Reported by:	Ryan Libby
Sponsored by:	Dell EMC Isilon
X-MFC with:	r313841
2017-02-17 03:27:20 +00:00