Module Name: src
Committed By: kamil
Date: Wed Jan 11 07:31:14 UTC 2017
Modified Files:
src/lib/libc/sys: ptrace.2
Log Message:
Document SIGTRAP with si_code TRAP_CHLD in ptrace(2)
Document the current behavior of TRAP_CHILD in NetBSD.
Add more notes on PTRACE_FORK events.
Sponsored by <The NetBSD Foundation>
To generate a diff of this commit:
cvs rdiff -u -r1.50 -r1.51 src/lib/libc/sys/ptrace.2
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/lib/libc/sys/ptrace.2
diff -u src/lib/libc/sys/ptrace.2:1.50 src/lib/libc/sys/ptrace.2:1.51
--- src/lib/libc/sys/ptrace.2:1.50 Sat Jan 7 05:51:14 2017
+++ src/lib/libc/sys/ptrace.2 Wed Jan 11 07:31:14 2017
@@ -1,7 +1,7 @@
-.\" $NetBSD: ptrace.2,v 1.50 2017/01/07 05:51:14 kamil Exp $
+.\" $NetBSD: ptrace.2,v 1.51 2017/01/11 07:31:14 kamil Exp $
.\"
.\" This file is in the public domain.
-.Dd January 7, 2016
+.Dd January 11, 2016
.Dt PTRACE 2
.Os
.Sh NAME
@@ -43,7 +43,7 @@ terminate or continue as appropriate.
.Fn ptrace
is the mechanism by which all this happens.
.Pp
-When a process that is traced by a debugger request and calls
+When a process that is traced by a debugger requests and calls
.Xr execve 2
or any of the routines built on it
.Po
@@ -90,6 +90,20 @@ with
.Dv si_code
set to
.Dv TRAP_TRACE .
+This event is always enabled and cannot be disabled.
+.Pp
+Child program traps are reported with
+.Dv SIGTRAP
+and the
+.Dv si_code
+value set to
+.Dv TRAP_CHLD .
+These events are by default disabled and can be configured with
+.Dv PT_SET_EVENT_MASK .
+If this event occurs,
+check with
+.Dv PT_GET_PROCESS_STATE
+the details of the process state associated with this event.
.Pp
A debugger might reuse a port specific symbols,
to help writing portable code as described in the port specific part of the
@@ -367,6 +381,23 @@ Report
.Xr fork 2 .
.El
.Pp
+The
+.Xr fork 2
+event can occur with similar operations,
+like
+.Xr clone 2
+or
+.Xr posix_spawn 2 .
+The
+.Dv PTRACE_FORK
+value means that process gives birth to its child
+without pending on its termination.
+If enabled,
+the child is also traced by the debugger and
+.Dv SIGRAP
+is generated twice,
+first for the parent and second for the child.
+.Pp
A pointer to this structure is passed in
.Fa addr .
The
