On 06/06/2017 11:53 PM, Mike Frysinger wrote: > From: Mike Frysinger <vapier@xxxxxxxxxxxx> > > First clarify that the process cannot catch this SIGSYS signal. While > the text currently says that, it's easy (imo) to read ambiguously and > that it's referring to default behavior (no handler -> process exits). > > Then add details regarding coredump behavior. Before Linux 4.11, there > was no way to get coredumps from such crashes. Now we can at least get > crashes from single threaded processes. Thanks, Mike. Patch applied. Cheers, Michael > Signed-off-by: Mike Frysinger <vapier@xxxxxxxxxxxx> > --- > man2/seccomp.2 | 16 ++++++++++++++++ > 1 file changed, 16 insertions(+) > > diff --git a/man2/seccomp.2 b/man2/seccomp.2 > index 7d0e721894b4..ec1df0c9efca 100644 > --- a/man2/seccomp.2 > +++ b/man2/seccomp.2 > @@ -378,6 +378,22 @@ The process terminates as though killed by a > signal > .RI ( not > .BR SIGKILL ). > +Even if a signal handler has been registered and otherwise catches > +.BR SIGSYS , > +the handler will be ignored in this case and the process always terminates. > + > +.\" See these commits: > +.\" seccomp: dump core when using SECCOMP_RET_KILL (b25e67161c295c98acda92123b2dd1e7d8642901) > +.\" seccomp: Only dump core when single-threaded (d7276e321ff8a53106a59c85ca46d03e34288893) > +Before Linux 4.11, any process terminated this way would not trigger a coredump > +(even though > +.B SIGSYS > +is documented in > +.BR signal (7) > +as having a default core action). > +Since Linux 4.11, single threaded processes follow standard coredump behavior, > +but multithreaded processes still do not. > +There is no workaround currently for multithreaded processes. > .TP > .BR SECCOMP_RET_TRAP > This value results in the kernel sending a > -- Michael Kerrisk Linux man-pages maintainer; http://www.kernel.org/doc/man-pages/ Linux/UNIX System Programming Training: http://man7.org/training/ -- To unsubscribe from this list: send the line "unsubscribe linux-man" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
