tracing: Fix null pointer deref with SEND_SIG_FORCED

[safe/jmp/linux-2.6] / include / trace / events / signal.h

diff --git a/include/trace/events/signal.h b/include/trace/events/signal.h
index ef51756..17df434 100644 (file)
--- a/include/trace/events/signal.h
+++ b/include/trace/events/signal.h
@@ -10,7 +10,8 @@
 
 #define TP_STORE_SIGINFO(__entry, info)                                \
        do {                                                    \
-               if (info == SEND_SIG_NOINFO) {                  \
+               if (info == SEND_SIG_NOINFO ||                  \
+                   info == SEND_SIG_FORCED) {                  \
                        __entry->errno  = 0;                    \
                        __entry->code   = SI_USER;              \
                } else if (info == SEND_SIG_PRIV) {             \
@@ -60,6 +61,105 @@ TRACE_EVENT(signal_generate,
                  __entry->comm, __entry->pid)
 );
 
+/**
+ * signal_deliver - called when a signal is delivered
+ * @sig: signal number
+ * @info: pointer to struct siginfo
+ * @ka: pointer to struct k_sigaction
+ *
+ * A 'sig' signal is delivered to current process with 'info' siginfo,
+ * and it will be handled by 'ka'. ka->sa.sa_handler can be SIG_IGN or
+ * SIG_DFL.
+ * Note that some signals reported by signal_generate tracepoint can be
+ * lost, ignored or modified (by debugger) before hitting this tracepoint.
+ * This means, this can show which signals are actually delivered, but
+ * matching generated signals and delivered signals may not be correct.
+ */
+TRACE_EVENT(signal_deliver,
+
+       TP_PROTO(int sig, struct siginfo *info, struct k_sigaction *ka),
+
+       TP_ARGS(sig, info, ka),
+
+       TP_STRUCT__entry(
+               __field(        int,            sig             )
+               __field(        int,            errno           )
+               __field(        int,            code            )
+               __field(        unsigned long,  sa_handler      )
+               __field(        unsigned long,  sa_flags        )
+       ),
+
+       TP_fast_assign(
+               __entry->sig    = sig;
+               TP_STORE_SIGINFO(__entry, info);
+               __entry->sa_handler     = (unsigned long)ka->sa.sa_handler;
+               __entry->sa_flags       = ka->sa.sa_flags;
+       ),
+
+       TP_printk("sig=%d errno=%d code=%d sa_handler=%lx sa_flags=%lx",
+                 __entry->sig, __entry->errno, __entry->code,
+                 __entry->sa_handler, __entry->sa_flags)
+);
+
+DECLARE_EVENT_CLASS(signal_queue_overflow,
+
+       TP_PROTO(int sig, int group, struct siginfo *info),
+
+       TP_ARGS(sig, group, info),
+
+       TP_STRUCT__entry(
+               __field(        int,    sig     )
+               __field(        int,    group   )
+               __field(        int,    errno   )
+               __field(        int,    code    )
+       ),
+
+       TP_fast_assign(
+               __entry->sig    = sig;
+               __entry->group  = group;
+               TP_STORE_SIGINFO(__entry, info);
+       ),
+
+       TP_printk("sig=%d group=%d errno=%d code=%d",
+                 __entry->sig, __entry->group, __entry->errno, __entry->code)
+);
+
+/**
+ * signal_overflow_fail - called when signal queue is overflow
+ * @sig: signal number
+ * @group: signal to process group or not (bool)
+ * @info: pointer to struct siginfo
+ *
+ * Kernel fails to generate 'sig' signal with 'info' siginfo, because
+ * siginfo queue is overflow, and the signal is dropped.
+ * 'group' is not 0 if the signal will be sent to a process group.
+ * 'sig' is always one of RT signals.
+ */
+DEFINE_EVENT(signal_queue_overflow, signal_overflow_fail,
+
+       TP_PROTO(int sig, int group, struct siginfo *info),
+
+       TP_ARGS(sig, group, info)
+);
+
+/**
+ * signal_lose_info - called when siginfo is lost
+ * @sig: signal number
+ * @group: signal to process group or not (bool)
+ * @info: pointer to struct siginfo
+ *
+ * Kernel generates 'sig' signal but loses 'info' siginfo, because siginfo
+ * queue is overflow.
+ * 'group' is not 0 if the signal will be sent to a process group.
+ * 'sig' is always one of non-RT signals.
+ */
+DEFINE_EVENT(signal_queue_overflow, signal_lose_info,
+
+       TP_PROTO(int sig, int group, struct siginfo *info),
+
+       TP_ARGS(sig, group, info)
+);
+
 #endif /* _TRACE_SIGNAL_H */
 
 /* This part must be outside protection */