CVS commit: src/sys/kern

["Kamil Rytarowski" <kamil%netbsd.org@localhost>]

Module Name:    src
Committed By:   kamil
Date:           Tue Oct  8 18:02:46 UTC 2019

Modified Files:
        src/sys/kern: kern_sig.c

Log Message:
Enhance reliability of ptrace(2) in a debuggee with multiple LWPs

Stop competing between threads which one emits event signal quicker and
overwriting the signal from another thread.

This fixes missed in action signals.

NetBSD truss can now report reliably all TRAP_SCE/SCX/etc events without
reports of missed ones.

his was one of the reasons why debuggee with multiple threads misbehaved
under a debugger.

This change is v.2 of the previously reverted commit for the same fix.

This version contains recovery path that stopps triggering event SIGTRAP
for a detached debugger.


To generate a diff of this commit:
cvs rdiff -u -r1.366 -r1.367 src/sys/kern/kern_sig.c

Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.