Commit Graph

4 Commits

Author SHA1 Message Date
Mark Johnston
c208cb9923 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
Mark Johnston
6c2806594b 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.
2016-04-17 23:08:47 +00:00
Mark Johnston
1c9a705223 Remove a couple of unused fields from the FBT probe struct. 2015-08-03 17:39:36 +00:00
Ruslan Bukin
b78ee15e9f First cut of DTrace for AArch64.
Reviewed by:	andrew, emaste
Sponsored by:	ARM Limited
Differential Revision:	https://reviews.freebsd.org/D2738
2015-07-01 15:51:11 +00:00