The current placement of get_signal_to_deliver() means that try_to_freeze() in get_signal_to_deliver() will happen after regs->psw.addr, regs->svcnr, and regs->gprs[2] may have been mangled. Since the app may get checkpointed while frozen and then restarted, this means we have to attempt a complicated and subtle re-calculation of the initial conditions.
If we just move the get_signal_to_deliver() above the immediately preceding block, we enourmously simplify the arch-specific checkpoint/restart code. A full ltp run seems to show no regressions do to this move, though I'm not familiar enough with the entry_64.S code in particular to be absolutely confident. Is this a bad idea? Signed-off-by: Serge E. Hallyn <[email protected]> --- arch/s390/kernel/signal.c | 8 ++++---- 1 files changed, 4 insertions(+), 4 deletions(-) diff --git a/arch/s390/kernel/signal.c b/arch/s390/kernel/signal.c index 1675c48..7dbd618 100644 --- a/arch/s390/kernel/signal.c +++ b/arch/s390/kernel/signal.c @@ -442,6 +442,10 @@ void do_signal(struct pt_regs *regs) else oldset = ¤t->blocked; + /* Get signal to deliver. When running under ptrace, at this point + the debugger may change all our registers ... */ + signr = get_signal_to_deliver(&info, &ka, regs, NULL); + /* Are we from a system call? */ if (regs->svcnr) { continue_addr = regs->psw.addr; @@ -463,10 +467,6 @@ void do_signal(struct pt_regs *regs) regs->svcnr = 0; /* Don't deal with this again. */ } - /* Get signal to deliver. When running under ptrace, at this point - the debugger may change all our registers ... */ - signr = get_signal_to_deliver(&info, &ka, regs, NULL); - /* Depending on the signal settings we may need to revert the decision to restart the system call. */ if (signr > 0 && regs->psw.addr == restart_addr) { -- 1.6.1 _______________________________________________ Containers mailing list [email protected] https://lists.linux-foundation.org/mailman/listinfo/containers _______________________________________________ Devel mailing list [email protected] https://openvz.org/mailman/listinfo/devel
