This was ported from illumos but not completely done. Currently we do
not perform type deduplication between KLDs and the kernel, i.e., kernel
modules have a complete type graph. So, remove it for now since it's
not functional and complicates the task of modifying various CTF type
definitions, and we are hitting some limits in the current format which
necessitate an update.
No functional change intended.
MFC after: 2 weeks
In both cases, too few frames were trimmed, leading to exception handling
or DTrace internals being exposed in stack traces exposed by D's stack()
primitive.
MFC after: 3 days
Reviewed by: emaste, andrew
To trace leaf asm functions we can insert a single nop instruction as
the first instruction in a function and trigger off this.
Reviewed by: gnn
Sponsored by: Innovate UK
Differential Revision: https://reviews.freebsd.org/D28132
high-resolution nanosecond timestamp used for the DTrace 'timestamp'
built-in variable. The new implementation uses the EL0 cycle
counter and frequency registers in ARMv8-A. This replaces a
previous implementation that relied on an instrumentation-safe
implementation of getnanotime(), which provided only timer
resolution.
MFC after: 3 days
Reviewed by: andrew, bsdimp (older version)
Useful comments appreciated: jrtc27, emaste
The existing implementation relies on each trap handler saving a normal
stack frame record, which is a waste of time and space when we're
already saving a trapframe to the stack. It's also wrong as it currently
saves LR not ELR.
Instead of patching it up, rewrite it based on the RISC-V implementation
with inspiration from the amd64 implementation for how to handle
vectored traps to provide an improved implementation. This includes
compressing the information down to one line like other architectures
rather than the highly-verbose old form that repeats itself by printing
LR and FP in one frame only to print them as PC and SP in the next. It
also includes printing out actually useful information about the traps
that occurred, though FAR is not saved in the trapframe so we cannot
print it (in general it can be clobbered between when the trap happened
and now), only ESR.
The AAPCS also allows the stack frame record to be located anywhere in
the frame, not just the top, so the caller's SP is not at a fixed offset
from the callee's FP like on almost all other architectures in
existence. This means there is no way to derive the caller's SP in the
unwinder, and so we have to drop that bit of (unused) state everywhere.
Reviewed by: jhb, markj
Differential Revision: https://reviews.freebsd.org/D28026
A more complete fix for this function is being worked on in D28054. Fix
the uninitialized variable error so that builds can at least proceed.
Reported by: several
Some stack frames are too large for a store pair instruction we already
detect in the arm64 fbt code. Add support for handling subtracting the
stack pointer directly.
Sponsored by: Innovate UK
When searching for an instruction to patch out in the arm64 function
boundary trace we search for a store pair with a write back. This
instruction is commonly used to store two registers to the stack
and update the stack pointer to hold space for more.
This works in many cases, however not all functions use this, e.g.
when the stack frame is too large. In these cases we may find another
instruction of the same type that doesn't store through the stack
pointer. Filter these instructions out and assume if we see one we
are past the function prologue.
Reported by: rwatson
Sponsored by: Innovate UK
- Implement a dtrace_getnanouptime(), matching the existing
dtrace_getnanotime(), to avoid DTrace calling out to a potentially
instrumentable function.
(These should probably both be under KDTRACE_HOOKS. Also, it's not clear
to me that they are correct implementations for the DTrace thread time
functions they are used in .. fixes for another commit.)
- Don't allow FBT to instrument functions involved in EL1 exception handling
that are involved in FBT trap processing: handle_el1h_sync() and
do_el1h_sync().
- Don't allow FBT to instrument DDB and KDB functions, as that makes it
rather harder to debug FBT problems.
Prior to these changes, use of FBT on FreeBSD/arm64 rapidly led to kernel
panics due to recursion in DTrace.
Reliable FBT on FreeBSD/arm64 is reliant on another change from @andrew to
have the aarch64 instrumentor more carefully check that instructions it
replaces are against the stack pointer, which can otherwise lead to memory
corruption. That change remains under review.
MFC after: 2 weeks
Reviewed by: andrew, kp, markj (earlier version), jrtc27 (earlier version)
Differential revision: https://reviews.freebsd.org/D27766
This same check is used on other architectures. Previously this would
permit a stack frame to unwind into any arbitrary kernel address
(including unmapped addresses).
Reviewed by: andrew, markj
Obtained from: CheriBSD
Sponsored by: DARPA
Differential Revision: https://reviews.freebsd.org/D27362
- Push the kstack_contains check down into unwind_frame() so that it
is honored by DDB and DTrace.
- Check that the trapframe for an exception frame is contained in the
traced thread's kernel stack for DDB traces.
Reviewed by: markj
Obtained from: CheriBSD
Sponsored by: DARPA
Differential Revision: https://reviews.freebsd.org/D27357
The sdt module's load handler iterates over SDT linker sets for the
kernel and all loaded modules to create probes and providers defined by
SDT(9). Probes in one module may belong to a provider in a different
module, but when a probe is created we assume that the provider is
already defined. To maintain this invariant, modify the load handler to
perform two separate passes over loaded modules: one to define providers
and the other to define probes.
The problem manifests when loading linux.ko, which depends on
linux_common.ko, which defines providers used by probes defined in
linux.ko.
Reported by: gallatin
MFC after: 2 weeks
Sponsored by: The FreeBSD Foundation
This catches up to the changes made to struct unwind_state in r364180.
Reviewed by: mhorne
Obtained from: CheriBSD
Sponsored by: DARPA
Differential Revision: https://reviews.freebsd.org/D27360
This is useful for stack unwinders which need to avoid out-of-bounds
reads of a kernel stack which can trigger kernel faults.
Reviewed by: kib, markj
Obtained from: CheriBSD
Sponsored by: DARPA
Differential Revision: https://reviews.freebsd.org/D27356
According to code comments the original motivation was to allow for
malloc_type_internal changes without ABI breakage. This can be trivially
accomplished by providing spare fields and versioning the struct, as
implemented in the patch below.
The upshots are one less memory indirection on each alloc and disappearance
of mt_zone.
Reviewed by: markj
Differential Revision: https://reviews.freebsd.org/D27104
Return values are passed in a0, so read it from there. We also pass a1 through
to userspace, as the ABI allows small structs to be returned in registers
a0/a1. While here read the register values directly from the trapframe rather
than rtval, and remove the now unneeded argument from dtrace_invop().
Set fbtp_roffset so that we get the correct return location in arg0.
Reviewed by: markj
Sponsored by: Axiado
Differential Revision: https://reviews.freebsd.org/D26389
The primary benefit is maintaining a completely shared
code base with the community allowing FreeBSD to receive
new features sooner and with less effort.
I would advise against doing 'zpool upgrade'
or creating indispensable pools using new
features until this change has had a month+
to soak.
Work on merging FreeBSD support in to what was
at the time "ZFS on Linux" began in August 2018.
I first publicly proposed transitioning FreeBSD
to (new) OpenZFS on December 18th, 2018. FreeBSD
support in OpenZFS was finally completed in December
2019. A CFT for downstreaming OpenZFS support in
to FreeBSD was first issued on July 8th. All issues
that were reported have been addressed or, for
a couple of less critical matters there are
pull requests in progress with OpenZFS. iXsystems
has tested and dogfooded extensively internally.
The TrueNAS 12 release is based on OpenZFS with
some additional features that have not yet made
it upstream.
Improvements include:
project quotas, encrypted datasets,
allocation classes, vectorized raidz,
vectorized checksums, various command line
improvements, zstd compression.
Thanks to those who have helped along the way:
Ryan Moeller, Allan Jude, Zack Welch, and many
others.
Sponsored by: iXsystems, Inc.
Differential Revision: https://reviews.freebsd.org/D25872
Since LA57 was moved to the main SDM document with revision 072, it
seems that we should have a support for it, and silicons are coming.
This patch makes pmap support both LA48 and LA57 hardware. The
selection of page table level is done at startup, kernel always
receives control from loader with 4-level paging. It is not clear how
UEFI spec would adapt LA57, for instance it could hand out control in
LA57 mode sometimes.
To switch from LA48 to LA57 requires turning off long mode, requesting
LA57 in CR4, then re-entering long mode. This is somewhat delicate
and done in pmap_bootstrap_la57(). AP startup in LA57 mode is much
easier, we only need to toggle a bit in CR4 and load right value in CR3.
I decided to not change kernel map for now. Single PML5 entry is
created that points to the existing kernel_pml4 (KML4Phys) page, and a
pml5 entry to create our recursive mapping for vtopte()/vtopde().
This decision is motivated by the fact that we cannot overcommit for
KVA, so large space there is unusable until machines start providing
wider physical memory addressing. Another reason is that I do not
want to break our fragile autotuning, so the KVA expansion is not
included into this first step. Nice side effect is that minidumps are
compatible.
On the other hand, (very) large address space is definitely
immediately useful for some userspace applications.
For userspace, numbering of pte entries (or page table pages) is
always done for 5-level structures even if we operate in 4-level mode.
The pmap_is_la57() function is added to report the mode of the
specified pmap, this is done not to allow simultaneous 4-/5-levels
(which is not allowed by hw), but to accomodate for EPT which has
separate level control and in principle might not allow 5-leve EPT
despite x86 paging supports it. Anyway, it does not seems critical to
have 5-level EPT support now.
Tested by: pho (LA48 hardware)
Reviewed by: alc
Sponsored by: The FreeBSD Foundation
Differential revision: https://reviews.freebsd.org/D25273
arg0 should be an offset of the return point within the function, arg1
should be the return value. Previously the return probe had arguments as
if for the entry probe.
Tested on armv7.
andrew noted that the same problem seems to be present on arm64, mips,
and riscv.
I am not sure if I will get around to fixing those. So, platform users
or anyone looking to make a contribution please be aware of this
opportunity.
Reviewed by: markj
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D25685
When emulating a load pair or store pair in dtrace on arm64 we need to
copy the data between the stack and trap frame. When the registers are
either the link register or the zero register we will access memory
past the end of the trap frame as these are encoded as registers 30 and
31 respectively while the array they access only has 30 entries.
Fix this by creating 2 helper functions to perform the operation with
special cases for these registers.
Sponsored by: Innovate UK
If DTRACE is enabled at compile time, all kernel breakpoint traps are
first given to dtrace to see if they are triggered by a FBT probe.
Previously if dtrace didn't recognize the trap, it was silently
ignored breaking the handling of other kernel breakpoint traps such as
the debug.kdb.enter sysctl. This only returns early from the trap
handler if dtrace recognizes the trap and handles it.
Submitted by: Nicolò Mazzucato <nicomazz97@gmail.com>
Reviewed by: markj
Obtained from: CheriBSD
Differential Revision: https://reviews.freebsd.org/D24478
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
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
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
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
'.' 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
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
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
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
