MFC 302900,302902,302921,303461,304009:

Add a mask of optional ptrace() events.

302900:
Add a test for user signal delivery.

This test verifies we get the correct ptrace event details when a signal
is posted to a traced process from userland.

302902:
Add a mask of optional ptrace() events.

ptrace() now stores a mask of optional events in p_ptevents.  Currently
this mask is a single integer, but it can be expanded into an array of
integers in the future.

Two new ptrace requests can be used to manipulate the event mask:
PT_GET_EVENT_MASK fetches the current event mask and PT_SET_EVENT_MASK
sets the current event mask.

The current set of events include:
- PTRACE_EXEC: trace calls to execve().
- PTRACE_SCE: trace system call entries.
- PTRACE_SCX: trace syscam call exits.
- PTRACE_FORK: trace forks and auto-attach to new child processes.
- PTRACE_LWP: trace LWP events.

The S_PT_SCX and S_PT_SCE events in the procfs p_stops flags have
been replaced by PTRACE_SCE and PTRACE_SCX.  PTRACE_FORK replaces
P_FOLLOW_FORK and PTRACE_LWP replaces P2_LWP_EVENTS.

The PT_FOLLOW_FORK and PT_LWP_EVENTS ptrace requests remain for
compatibility but now simply toggle corresponding flags in the
event mask.

While here, document that PT_SYSCALL, PT_TO_SCE, and PT_TO_SCX both
modify the event mask and continue the traced process.

302921:
Rename PTRACE_SYSCALL to LINUX_PTRACE_SYSCALL.

303461:
Note that not all optional ptrace events use SIGTRAP.

New child processes attached due to PTRACE_FORK use SIGSTOP instead of
SIGTRAP.  All other ptrace events use SIGTRAP.

304009:
Remove description of P_FOLLOWFORK as this flag was removed.

1 files changed, 1 insertions, 2 deletions

diff --git a/bin/ps/ps.1 b/bin/ps/ps.1
index 3d7c738..ad606dc 100644
--- a/bin/ps/ps.1
+++ b/bin/ps/ps.1
@@ -29,7 +29,7 @@
 .\"     @(#)ps.1	8.3 (Berkeley) 4/18/94
 .\" $FreeBSD$
 .\"
-.Dd December 1, 2015
+.Dd August 12, 2016
 .Dt PS 1
 .Os
 .Sh NAME
@@ -319,7 +319,6 @@ the include file
 .It Dv "P_ADVLOCK" Ta No "0x00001" Ta "Process may hold a POSIX advisory lock"
 .It Dv "P_CONTROLT" Ta No "0x00002" Ta "Has a controlling terminal"
 .It Dv "P_KPROC" Ta No "0x00004" Ta "Kernel process"
-.It Dv "P_FOLLOWFORK" Ta No "0x00008" Ta "Attach debugger to new children"
 .It Dv "P_PPWAIT" Ta No "0x00010" Ta "Parent is waiting for child to exec/exit"
 .It Dv "P_PROFIL" Ta No "0x00020" Ta "Has started profiling"
 .It Dv "P_STOPPROF" Ta No "0x00040" Ta "Has thread in requesting to stop prof"