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
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
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
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
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.
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.
- 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
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
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.
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
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.
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.
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
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
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
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
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
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
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@
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
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
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
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
dtrace_trap() consumes page and protection faults triggered by code running
in DTrace probe context. Such faults occur with interrupts disabled and are
detected using a per-CPU flag. Regular faults cause dtrace_trap() to be
called with interrupts enabled, and nothing was ensuring that the flag was
read from the correct CPU. This may result in dtrace_trap() consuming
unrelated page and protection faults when DTrace is enabled, causing the
fault handler to return without actually having handled the fault.
Diagnosed by: Ryan Libby <rlibby@gmail.com>
MFC after: 3 days
Sponsored by: Dell EMC Isilon
When recording probe site addresses in the output DOF file, dtrace -G
needs to emit relocations for the .SUNW_dof section in order to obtain
the addresses of functions containing probe sites. DTrace expects the
addresses to be relative to the base address of the final ELF file,
and the amd64 USDT implementation was relying on some unspecified and
incorrect behaviour in the base system GNU ld to achieve this.
This change reimplements the probe site relocation handling to allow
USDT to be used with lld and newer GNU binutils. Specifically, it
makes use of R_X86_64_PC64/R_386_PC32 relocations to obtain the
probe site address relative to the DOF file address, and adds and uses a
new DOF relocation type which computes the final probe site address using
these relative offsets.
Reported by and discussed with: Rafael Espíndola
MFC after: 1 month
Differential Revision: https://reviews.freebsd.org/D9374
This corresponds to the following illumos issues:
5755 want support for Intel FMA instrs
5756 want support for Intel BMI1 instrs
5757 want support for Intel BMI2 instrs
5758 want support for Intel AVX2 instrs
7204 Want broadwell rdseed and adx support
7208 Want stac/clac disasm support
7733 Need SHA Instruction dis support
7756 dis can't handle x86 SSE 3 instructions
7757 want avx2 disasm tests
7758 want SSE 4.1 disasm tests
MFC after: 2 weeks
This ioctl has been considered legacy by upstream since the DTrace code
was first imported, and is unused. The removal also allows some
simplification of dtrace_helper_slurp().
Also remove a bogus copyout in the DTRACEHIOC_ADDDOF handler. Due to a
bug, it would overwrite an in-memory copy of the DOF header rather than
the passed-in DOF helper. Moreover, DTRACEHIOC_ADDDOF already copies the
helper back out automatically since its argument has the IOC_OUT attribute.
the fifth argument to functions being traced, however there was an error
where the userspace stack was being used. This may be invalid leading to
a kernel panic if this address is unmapped.
Submitted by: Graeme Jenkinson <graeme.jenkinson@cl.cam.ac.uk>
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D9229
These functions may be called in DTrace probe context, so they cannot be
safely traced. Moreover, they are currently only used by DTrace, so their
corresponding FBT probes are not particularly useful.
MFC after: 2 weeks
