From: Heiko Carstens Date: Mon, 27 Oct 2014 14:49:06 +0000 (+0100) Subject: s390/ftrace: add ftrace_graph_is_dead() check X-Git-Tag: v3.18-rc4~21^2 X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=6ed15ea67b5ebb13ececcfc6056d90a70ed96f7b;p=users%2Fdwmw2%2Flinux.git s390/ftrace: add ftrace_graph_is_dead() check Add an ftrace_graph_is_dead() check to prepare_ftrace_return() in order to detect an internal ftrace graph error. This allows to prevent further ftrace graph handling and hopefully keeps the kernel alive. This patch is the same like for all other architectures. For unkown reasons s390 was left out. Signed-off-by: Heiko Carstens Signed-off-by: Martin Schwidefsky --- diff --git a/arch/s390/kernel/ftrace.c b/arch/s390/kernel/ftrace.c index 51d14fe5eb9a3..ca1cabb3a96c1 100644 --- a/arch/s390/kernel/ftrace.c +++ b/arch/s390/kernel/ftrace.c @@ -121,6 +121,8 @@ unsigned long __kprobes prepare_ftrace_return(unsigned long parent, { struct ftrace_graph_ent trace; + if (unlikely(ftrace_graph_is_dead())) + goto out; if (unlikely(atomic_read(¤t->tracing_graph_pause))) goto out; ip = (ip & PSW_ADDR_INSN) - MCOUNT_INSN_SIZE;