Add signal instrumentation
authorMathieu Desnoyers <mathieu.desnoyers@efficios.com>
Thu, 16 Feb 2012 15:46:32 +0000 (10:46 -0500)
committerMathieu Desnoyers <mathieu.desnoyers@efficios.com>
Thu, 16 Feb 2012 15:56:40 +0000 (10:56 -0500)
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
instrumentation/events/lttng-module/signal.h [new file with mode: 0644]
instrumentation/events/mainline/signal.h [new file with mode: 0644]
probes/Makefile
probes/lttng-probe-signal.c [new file with mode: 0644]

diff --git a/instrumentation/events/lttng-module/signal.h b/instrumentation/events/lttng-module/signal.h
new file mode 100644 (file)
index 0000000..3fa7f5b
--- /dev/null
@@ -0,0 +1,164 @@
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM signal
+
+#if !defined(_TRACE_SIGNAL_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_SIGNAL_H
+
+#include <linux/tracepoint.h>
+
+#ifndef _TRACE_SIGNAL_DEF
+#define _TRACE_SIGNAL_DEF
+#include <linux/signal.h>
+#include <linux/sched.h>
+#define TP_STORE_SIGINFO(info)                                 \
+               tp_assign(errno,                                \
+                       (info == SEND_SIG_NOINFO || info == SEND_SIG_FORCED || info == SEND_SIG_PRIV) ? \
+                       0 :                                     \
+                       info->si_errno)                         \
+               tp_assign(code,                                 \
+                       (info == SEND_SIG_NOINFO || info == SEND_SIG_FORCED) ? \
+                       SI_USER :                               \
+                       ((info == SEND_SIG_PRIV) ? SI_KERNEL : info->si_code))
+#endif /* _TRACE_SIGNAL_DEF */
+
+/**
+ * signal_generate - called when a signal is generated
+ * @sig: signal number
+ * @info: pointer to struct siginfo
+ * @task: pointer to struct task_struct
+ *
+ * Current process sends a 'sig' signal to 'task' process with
+ * 'info' siginfo. If 'info' is SEND_SIG_NOINFO or SEND_SIG_PRIV,
+ * 'info' is not a pointer and you can't access its field. Instead,
+ * SEND_SIG_NOINFO means that si_code is SI_USER, and SEND_SIG_PRIV
+ * means that si_code is SI_KERNEL.
+ */
+TRACE_EVENT(signal_generate,
+
+       TP_PROTO(int sig, struct siginfo *info, struct task_struct *task),
+
+       TP_ARGS(sig, info, task),
+
+       TP_STRUCT__entry(
+               __field(        int,    sig                     )
+               __field(        int,    errno                   )
+               __field(        int,    code                    )
+               __array(        char,   comm,   TASK_COMM_LEN   )
+               __field(        pid_t,  pid                     )
+       ),
+
+       TP_fast_assign(
+               tp_assign(sig, sig)
+               TP_STORE_SIGINFO(info)
+               tp_memcpy(comm, task->comm, TASK_COMM_LEN)
+               tp_assign(pid, task->pid)
+       ),
+
+       TP_printk("sig=%d errno=%d code=%d comm=%s pid=%d",
+                 __entry->sig, __entry->errno, __entry->code,
+                 __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(
+               tp_assign(sig, sig)
+               TP_STORE_SIGINFO(info)
+               tp_assign(sa_handler, (unsigned long)ka->sa.sa_handler)
+               tp_assign(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(
+               tp_assign(sig, sig)
+               tp_assign(group, group)
+               TP_STORE_SIGINFO(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 */
+#include "../../../probes/define_trace.h"
diff --git a/instrumentation/events/mainline/signal.h b/instrumentation/events/mainline/signal.h
new file mode 100644 (file)
index 0000000..17df434
--- /dev/null
@@ -0,0 +1,166 @@
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM signal
+
+#if !defined(_TRACE_SIGNAL_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_SIGNAL_H
+
+#include <linux/signal.h>
+#include <linux/sched.h>
+#include <linux/tracepoint.h>
+
+#define TP_STORE_SIGINFO(__entry, info)                                \
+       do {                                                    \
+               if (info == SEND_SIG_NOINFO ||                  \
+                   info == SEND_SIG_FORCED) {                  \
+                       __entry->errno  = 0;                    \
+                       __entry->code   = SI_USER;              \
+               } else if (info == SEND_SIG_PRIV) {             \
+                       __entry->errno  = 0;                    \
+                       __entry->code   = SI_KERNEL;            \
+               } else {                                        \
+                       __entry->errno  = info->si_errno;       \
+                       __entry->code   = info->si_code;        \
+               }                                               \
+       } while (0)
+
+/**
+ * signal_generate - called when a signal is generated
+ * @sig: signal number
+ * @info: pointer to struct siginfo
+ * @task: pointer to struct task_struct
+ *
+ * Current process sends a 'sig' signal to 'task' process with
+ * 'info' siginfo. If 'info' is SEND_SIG_NOINFO or SEND_SIG_PRIV,
+ * 'info' is not a pointer and you can't access its field. Instead,
+ * SEND_SIG_NOINFO means that si_code is SI_USER, and SEND_SIG_PRIV
+ * means that si_code is SI_KERNEL.
+ */
+TRACE_EVENT(signal_generate,
+
+       TP_PROTO(int sig, struct siginfo *info, struct task_struct *task),
+
+       TP_ARGS(sig, info, task),
+
+       TP_STRUCT__entry(
+               __field(        int,    sig                     )
+               __field(        int,    errno                   )
+               __field(        int,    code                    )
+               __array(        char,   comm,   TASK_COMM_LEN   )
+               __field(        pid_t,  pid                     )
+       ),
+
+       TP_fast_assign(
+               __entry->sig    = sig;
+               TP_STORE_SIGINFO(__entry, info);
+               memcpy(__entry->comm, task->comm, TASK_COMM_LEN);
+               __entry->pid    = task->pid;
+       ),
+
+       TP_printk("sig=%d errno=%d code=%d comm=%s pid=%d",
+                 __entry->sig, __entry->errno, __entry->code,
+                 __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 */
+#include <trace/define_trace.h>
index ff6b9291f00eb377f4df2e56bc73561621e42020..d86ee87d27856e9113dc06356ce4f97dabb96b2e 100644 (file)
@@ -12,6 +12,7 @@ obj-m += lttng-probe-lttng.o
 
 obj-m += lttng-probe-sched.o
 obj-m += lttng-probe-irq.o
+obj-m += lttng-probe-signal.o
 
 obj-m += lttng-probe-statedump.o
 
diff --git a/probes/lttng-probe-signal.c b/probes/lttng-probe-signal.c
new file mode 100644 (file)
index 0000000..0de88bc
--- /dev/null
@@ -0,0 +1,30 @@
+/*
+ * probes/lttng-probe-signal.c
+ *
+ * Copyright 2012 (c) - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ *
+ * LTTng signal probes.
+ *
+ * Dual LGPL v2.1/GPL v2 license.
+ */
+
+#include <linux/module.h>
+
+/*
+ * Create the tracepoint static inlines from the kernel to validate that our
+ * trace event macros match the kernel we run on.
+ */
+#include <trace/events/irq.h>
+
+/*
+ * Create LTTng tracepoint probes.
+ */
+#define LTTNG_PACKAGE_BUILD
+#define CREATE_TRACE_POINTS
+#define TRACE_INCLUDE_PATH ../instrumentation/events/lttng-module
+
+#include "../instrumentation/events/lttng-module/signal.h"
+
+MODULE_LICENSE("GPL and additional rights");
+MODULE_AUTHOR("Mathieu Desnoyers <mathieu.desnoyers@efficios.com>");
+MODULE_DESCRIPTION("LTTng signal probes");
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