On Tue, Sep 19, 2023 at 04:35:31PM +0300, Konstantin Belousov wrote: > On Tue, Sep 19, 2023 at 03:39:21PM +0300, Dmitry Chagin wrote: > > On Tue, Sep 19, 2023 at 01:42:26PM +0300, Konstantin Belousov wrote: > > > On Tue, Sep 19, 2023 at 01:05:07PM +0300, Dmitry Chagin wrote: > > > > On Tue, Sep 19, 2023 at 12:05:42AM +0300, Konstantin Belousov wrote: > > > > > On Mon, Sep 18, 2023 at 02:53:25PM +0000, Dmitry Chagin wrote: > > > > > > The branch main has been updated by dchagin: > > > > > > > > > > > > URL: > > > > > > https://cgit.FreeBSD.org/src/commit/?id=227d01c1bc7caf2e838ee6eef1e6a3cc81d79d1b > > > > > > > > > > > > commit 227d01c1bc7caf2e838ee6eef1e6a3cc81d79d1b > > > > > > Author: Dmitry Chagin <dcha...@freebsd.org> > > > > > > AuthorDate: 2023-09-18 14:53:01 +0000 > > > > > > Commit: Dmitry Chagin <dcha...@freebsd.org> > > > > > > CommitDate: 2023-09-18 14:53:01 +0000 > > > > > > > > > > > > linux(4): On Linux SIGKILL can not be reset to default > > > > > > > > > > > > MFC after: 1 week > > > > > > --- > > > > > > sys/compat/linux/linux_signal.c | 5 ++++- > > > > > > 1 file changed, 4 insertions(+), 1 deletion(-) > > > > > > > > > > > > diff --git a/sys/compat/linux/linux_signal.c > > > > > > b/sys/compat/linux/linux_signal.c > > > > > > index e3e3fc74a6a9..9a84700b3949 100644 > > > > > > --- a/sys/compat/linux/linux_signal.c > > > > > > +++ b/sys/compat/linux/linux_signal.c > > > > > > @@ -170,6 +170,7 @@ linux_do_sigaction(struct thread *td, int > > > > > > linux_sig, l_sigaction_t *linux_nsa, > > > > > > > > > > > > if (!LINUX_SIG_VALID(linux_sig)) > > > > > > return (EINVAL); > > > > > > + sig = linux_to_bsd_signal(linux_sig); > > > > > > > > > > > > osa = (linux_osa != NULL) ? &oact : NULL; > > > > > > if (linux_nsa != NULL) { > > > > > > @@ -180,9 +181,11 @@ linux_do_sigaction(struct thread *td, int > > > > > > linux_sig, l_sigaction_t *linux_nsa, > > > > > > linux_ktrsigset(&linux_nsa->lsa_mask, > > > > > > sizeof(linux_nsa->lsa_mask)); > > > > > > #endif > > > > > > + if ((sig == SIGKILL || sig == SIGSTOP) && > > > > > > + nsa->sa_handler == SIG_DFL) > > > > > > + return (EINVAL); > > > > > This is excessive: look at kern_sigaction() around line 822. > > > > > > > > > > > > > Well, I checkd that before, Bruce added this check a long time ago, > > > > however, Bruce's change allows the handler to be set to SIG_DFL. > > > > And I haven't found an explicit statement of how it should be in POSIX, > > > > so I think it's Linux specific > > > > > > > > > > If kern_sigaction() allows to change SIGKILL or SIGSTOP disposition from > > > default, we have a serious issue. The check above simply repeats the > > > check from kern_sigaction(). > > > > Hmm, why? Native kern_sigaction check: > > > > if ((sig == SIGKILL || sig == SIGSTOP) && > > act->sa_handler != SIG_DFL) { > > > > ^^^^^^^ this allows to set sa_handler to > > SIG_DFL, > > but Linux forbids this > > > > mtx_unlock(&ps->ps_mtx); > > PROC_UNLOCK(p); > > return (EINVAL); > > } > > > > And I found in the POSIX: > > > > It is unspecified whether an attempt to set the action for a signal that > > cannot be caught or ignored to SIG_DFL is ignored or causes an error to > > be returned with errno set to [EINVAL]. > > > > The sigaction() function may fail if: > > [EINVAL] > > An attempt was made to set the action to SIG_DFL for a > > signal that cannot be caught or ignored (or both). > > > > Linux returns EINVAL in that case, FreeBSD does not, both are valid? > Ah, I see. Thank you for the explanation. > > What was the commit where bde added the check?
e6eeb36d
