Hi Dave, On 5/12/20 6:36 PM, Dave Martin wrote: > In reality, almost every prctl interferes with assumptions that the > compiler and C library / runtime rely on. prctl() can therefore > make userspace explode in a variety ways that are likely to be hard > to debug. > > This is not obvious to the uninitiated, so add a warning. Patch applied. But see my comments on patch 04. I may want to circle back on this patch later, since the wording feels a little strong to me (we simply must use prctl for some things, and not all of those things break user-space/runtime as far as I know). If you have some thoughts on softening the warning, let me know. Cheers, Michael > Signed-off-by: Dave Martin <Dave.Martin@xxxxxxx> > --- > man2/prctl.2 | 5 +++++ > 1 file changed, 5 insertions(+) > > diff --git a/man2/prctl.2 b/man2/prctl.2 > index 7932ada..a35b748 100644 > --- a/man2/prctl.2 > +++ b/man2/prctl.2 > @@ -66,6 +66,11 @@ prctl \- operations on a process or thread > manipulates various aspects of the behavior > of the calling thread or process. > .PP > +Note that careless use of > +.BR prctl () > +can confuse the userspace run-time environment, > +so these operations should be used with care (if at all). > +.PP > .BR prctl () > is called with a first argument describing what to do > (with values defined in \fI<linux/prctl.h>\fP), and further > -- Michael Kerrisk Linux man-pages maintainer; http://www.kernel.org/doc/man-pages/ Linux/UNIX System Programming Training: http://man7.org/training/
