* Stas Sergeev <stsp@xxxxxxx> [2016-03-01 00:29:03 +0300]: > The following patches make it possible to use swapcontext() > in a sighandler that works on sigaltstack. i don't think that's possible, the (obsolete) userspace *context functions cannot operate on kernel provided ucontext_t structs, so they are not usable in signal handlers. at least not on most target archs. so i don't understand how the tests can work portably. > The approach is inspired by Andy Lutomirski's suggestion that > sigaltstack should disarm itself after saving into uc_stack: > https://lkml.org/lkml/2016/2/1/594 > > I add the SS_AUTODISARM flag that does exactly that. > On sighandler exit, the sigaltstack is restored from uc_stack. > Another possible name could be SS_ONESHOT, but, since it gets > always re-enabled, I choose SS_AUTODISARM. > > [PATCH 1/2] sigaltstack: implement SS_AUTODISARM flag > This patch implements SS_AUTODISARM flag > [PATCH 2/2] selftests: Add test for sigaltstack(SS_AUTODISARM) > This patch adds the selftest code for new functionality > > CC: linux-kernel@xxxxxxxxxxxxxxx > CC: linux-api@xxxxxxxxxxxxxxx > CC: Andy Lutomirski <luto@xxxxxxxxxxxxxx> > CC: Oleg Nesterov <oleg@xxxxxxxxxx> > CC: Shuah Khan <shuahkh@xxxxxxxxxxxxxxx> > > Diffstat: > include/linux/sched.h | 8 + > include/linux/signal.h | 4 > include/uapi/linux/signal.h | 3 > kernel/fork.c | 2 > kernel/signal.c | 23 ++-- > tools/testing/selftests/Makefile | 1 > tools/testing/selftests/sigaltstack/Makefile | 8 + > tools/testing/selftests/sigaltstack/sas.c | 151 +++++++++++++++++++++++++++ > 8 files changed, 187 insertions(+), 13 deletions(-) > > -- > To unsubscribe from this list: send the line "unsubscribe linux-api" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-api" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
