sys: Remove $FreeBSD$: two-line .h pattern

Remove /^\s*\*\n \*\s+\$FreeBSD\$$\n/

dtrace: Add a "regs" variable

This allows invop-based providers (i.e., fbt and kinst) to expose the
register file of the CPU at the point where the probe fired. It does
not work for SDT providers b

dtrace: Add a "regs" variable

This allows invop-based providers (i.e., fbt and kinst) to expose the
register file of the CPU at the point where the probe fired. It does
not work for SDT providers because their probes are implemented as plain
function calls and so don't save registers. It's not clear what
semantics "regs" should have for them anyway.

This is akin to "uregs", which nominally provides access to the
userspace registers. In fact, DIF already had a DIF_VAR_REGS variable
defined, it was simply unimplemented.

Usage example: print the contents of %rdi upon each call to
amd64_syscall():

fbt::amd64_syscall:entry {printf("%x", regs[R_RDI]);}

Note that the R_* constants are defined in /usr/lib/dtrace/regs_x86.d.
Currently there are no similar definitions for non-x86 platforms.

Reviewed by: christos
MFC after: 2 weeks
Differential Revision: https://reviews.freebsd.org/D36799

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Adjust function definition in powerpc's dtrace_subr.c to avoid clang 15 warning

With clang 15, the following -Werror warning is produced:

sys/cddl/dev/dtrace/powerpc/dtrace_subr.c:237:17: error

Adjust function definition in powerpc's dtrace_subr.c to avoid clang 15 warning

With clang 15, the following -Werror warning is produced:

sys/cddl/dev/dtrace/powerpc/dtrace_subr.c:237:17: error: a function declaration without a prototype is deprecated in all versions of C [-Werror,-Wstrict-prototypes]
dtrace_gethrtime()
^
void

This is because dtrace_gethrtime() is declared with a (void) argument
list, but defined with an empty argument list. Make the definition match
the declaration.

MFC after: 3 days

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Merge ^/head r319548 through r319778.

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 threa

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@

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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
D

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

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Add an EARLY_AP_STARTUP option to start APs earlier during boot.

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

Add an EARLY_AP_STARTUP option to start APs earlier during boot.

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

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Make the second argument of dtrace_invop() a trapframe pointer.

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 archi

Make the second argument of dtrace_invop() a trapframe pointer.

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.

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MFH

Sponsored by: The FreeBSD Foundation

Remove unused variables dtrace_in_probe and dtrace_in_probe_addr.

Merge sync of head

MFH: r278968-r280640

Sponsored by: The FreeBSD Foundation

Merge from head

Merging ^/head r279596 through r279758.

Merge r278538 through r279716.

Fix build after unifying DAR/DEAR storage in trap frame.

Reintegrate head: r274132-r277384

Sponsored by: The FreeBSD Foundation

Reintegrate head revisions r273096-r277147

Sponsored by: The FreeBSD Foundation

MFhead @ r276594

Merge ^/head r274961 through r276301.

Restore the trap type argument to the DTrace trap hook, removed in r268600.
It's redundant at the moment since it can be obtained from the trapframe
on the architectures where DTrace is supported, bu

Restore the trap type argument to the DTrace trap hook, removed in r268600.
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.

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IFC @r269962

Submitted by: Anish Gupta (akgupt3@gmail.com)

Merge head from 7/28

Sync to HEAD@r269943.

Invoke the DTrace trap handler before calling trap() on amd64. This matches
the upstream implementation and helps ensure that a trap induced by tracing
fbt::trap:entry is handled without recursively

Invoke the DTrace trap handler before calling trap() on amd64. This matches
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

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