From 0ec73ddce557ac36a2782a726ab5a00663c2e50d Mon Sep 17 00:00:00 2001 From: Mathieu Desnoyers Date: Thu, 16 Feb 2012 10:46:32 -0500 Subject: [PATCH] Add signal instrumentation Signed-off-by: Mathieu Desnoyers --- instrumentation/events/lttng-module/signal.h | 164 ++++++++++++++++++ instrumentation/events/mainline/signal.h | 166 +++++++++++++++++++ probes/Makefile | 1 + probes/lttng-probe-signal.c | 30 ++++ 4 files changed, 361 insertions(+) create mode 100644 instrumentation/events/lttng-module/signal.h create mode 100644 instrumentation/events/mainline/signal.h create mode 100644 probes/lttng-probe-signal.c diff --git a/instrumentation/events/lttng-module/signal.h b/instrumentation/events/lttng-module/signal.h new file mode 100644 index 00000000..3fa7f5b1 --- /dev/null +++ b/instrumentation/events/lttng-module/signal.h @@ -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 + +#ifndef _TRACE_SIGNAL_DEF +#define _TRACE_SIGNAL_DEF +#include +#include +#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 index 00000000..17df4346 --- /dev/null +++ b/instrumentation/events/mainline/signal.h @@ -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 +#include +#include + +#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 diff --git a/probes/Makefile b/probes/Makefile index ff6b9291..d86ee87d 100644 --- a/probes/Makefile +++ b/probes/Makefile @@ -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 index 00000000..0de88bc8 --- /dev/null +++ b/probes/lttng-probe-signal.c @@ -0,0 +1,30 @@ +/* + * probes/lttng-probe-signal.c + * + * Copyright 2012 (c) - Mathieu Desnoyers + * + * LTTng signal probes. + * + * Dual LGPL v2.1/GPL v2 license. + */ + +#include + +/* + * Create the tracepoint static inlines from the kernel to validate that our + * trace event macros match the kernel we run on. + */ +#include + +/* + * 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 "); +MODULE_DESCRIPTION("LTTng signal probes"); -- 2.34.1