CVS commit: src/sys/kern

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

Module Name:    src
Committed By:   kamil
Date:           Thu Jul 18 20:10:46 UTC 2019

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

Log Message:
Enhance locking of ptrace_update_lwp

Replace lwp_delref() + mutex_enter() with: mutex_enter() + lwp_delref2().
This avoids extra taking and exiting from a mutex.

Add missing mutex_exit() for LW_SYSTEM.

Do not switch lwp for PT_SET_SIGINFO. This operation is not needed and
avoids panic for >2 LWPs as p_lock is attempted to be entered again in a
critical section.


To generate a diff of this commit:
cvs rdiff -u -r1.57 -r1.58 src/sys/kern/sys_ptrace_common.c

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