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
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
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
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.
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.
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
