Re: man-pages-3.37 is released

From: Denys Vlasenko
Date: Fri Mar 23 2012 - 08:52:01 EST


Hi Michael,

On Mon, Mar 19, 2012 at 7:29 PM, Michael Kerrisk (man-pages)
<mtk.manpages@xxxxxxxxx> wrote:
> On Sat, Mar 17, 2012 at 1:16 PM, Denys Vlasenko
> <vda.linux@xxxxxxxxxxxxxx> wrote:
>> On Friday 09 March 2012 18:27, Michael Kerrisk (man-pages) wrote:
>>> ptrace.2
>>>     Denys Vlasenko  [Oleg Nesterov, Tejun Heo]
>>>         add extended description of various ptrace quirks
>>
>> Pulled current git and spotted a few broken places.
>
> I made a few light edits to your patch, but basically applied it as
> given for man-pages-3.38.

Thanks! I found one tiny markup bug.

Also, I want to add info about PTRACE_GETEVENTMSG on
PTRACE_EVENT_EXEC. We document PTRACE_GETEVENTMSG
on all other PTRACE_EVENT_foo's, except EXEC.
That's not fair :)

Please find the patch attached.

--
vda
diff --git a/man2/ptrace.2 b/man2/ptrace.2
index 5a8b648..0e7ca08 100644
--- a/man2/ptrace.2
+++ b/man2/ptrace.2
@@ -374,6 +374,10 @@ value such that
status>>8 == (SIGTRAP | (PTRACE_EVENT_EXEC<<8))
.fi

+If execing thread is not a thread group leader, thread ID
+is reset to thread group leader's ID before this stop.
+Since Linux 3.0, the former thread ID can be retrieved with
+.BR PTRACE_GETEVENTMSG .
.TP
.BR PTRACE_O_TRACEVFORKDONE " (since Linux 2.5.60)"
Stop the tracee at the completion of the next
@@ -1018,6 +1022,9 @@ can be used to retrieve the new thread's ID.
.B PTRACE_EVENT_EXEC
Stop before return from
.BR execve (2).
+Since Linux 3.0,
+.BR PTRACE_GETEVENTMSG
+returns the former thread ID.
.TP
.B PTRACE_EVENT_EXIT
Stop before exit (including death from
@@ -1039,7 +1046,8 @@ to finish exiting.
on
.B PTRACE_EVENT
stops returns
-.B SIGTRAP in
+.B SIGTRAP
+in
.IR si_signo ,
with
.I si_code