Disable tracing on FreeBSD using procctl. (OpenSSH Portable 8.8)

[Ed Maste]

On Tue, 19 Oct 2021 at 13:40, Ed Maste <emaste at freebsd.org> wrote:
>
> On Fri, 15 Oct 2021 at 13:07, Bryan Drewery <bdrewery at freebsd.org> wrote:
> >
> > I think the tests may need to be improved as pid==0 represents a pseudo
> > kernel process.
>
> This is being fixed, but for compatibility with existing versions
> getpid() should indeed be used.

This fix is still outstanding:

    Fix tracing disable on FreeBSD

    Some versions of FreeBSD do not support using id 0 to refer to the
    current pid for procctl, so pass getpid() explicitly.

--- a/platform-tracing.c
+++ b/platform-tracing.c
@@ -32,6 +32,7 @@
 #include <stdarg.h>
 #include <stdio.h>
 #include <string.h>
+#include <unistd.h>

 #include "log.h"

@@ -42,7 +43,7 @@ platform_disable_tracing(int strict)
        /* On FreeBSD, we should make this process untraceable */
        int disable_trace = PROC_TRACE_CTL_DISABLE;

-       if (procctl(P_PID, 0, PROC_TRACE_CTL, &disable_trace) && strict)
+       if (procctl(P_PID, getpid(), PROC_TRACE_CTL, &disable_trace) && strict)
                fatal("unable to make the process untraceable: %s",
                    strerror(errno));
 #endif