Commit 7ead8b83 authored by Li Zefan's avatar Li Zefan Committed by Ingo Molnar

tracing/events: Add module tracepoints

Add trace points to trace module_load, module_free, module_get,
module_put and module_request, and use trace_event facility to
get the trace output.

Here's the sample output:

     TASK-PID    CPU#    TIMESTAMP  FUNCTION
        | |       |          |         |
    <...>-42    [000]     1.758380: module_request: fb0 wait=1 call_site=fb_open
    ...
    <...>-60    [000]     3.269403: module_load: scsi_wait_scan
    <...>-60    [000]     3.269432: module_put: scsi_wait_scan call_site=sys_init_module refcnt=0
    <...>-61    [001]     3.273168: module_free: scsi_wait_scan
    ...
    <...>-1021  [000]    13.836081: module_load: sunrpc
    <...>-1021  [000]    13.840589: module_put: sunrpc call_site=sys_init_module refcnt=-1
    <...>-1027  [000]    13.848098: module_get: sunrpc call_site=try_module_get refcnt=0
    <...>-1027  [000]    13.848308: module_get: sunrpc call_site=get_filesystem refcnt=1
    <...>-1027  [000]    13.848692: module_put: sunrpc call_site=put_filesystem refcnt=0
    ...
 modprobe-2587  [001]  1088.437213: module_load: trace_events_sample F
 modprobe-2587  [001]  1088.437786: module_put: trace_events_sample call_site=sys_init_module refcnt=0

Note:

- the taints flag can be 'F', 'C' and/or 'P' if mod->taints != 0

- the module refcnt is percpu, so it can be negative in a
  specific cpu
Signed-off-by: default avatarLi Zefan <lizf@cn.fujitsu.com>
Acked-by: default avatarRusty Russell <rusty@rustcorp.com.au>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
LKML-Reference: <4A891B3C.5030608@cn.fujitsu.com>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent 60d970c2
......@@ -17,10 +17,12 @@
#include <linux/moduleparam.h>
#include <linux/marker.h>
#include <linux/tracepoint.h>
#include <asm/local.h>
#include <asm/local.h>
#include <asm/module.h>
#include <trace/events/module.h>
/* Not Yet Implemented */
#define MODULE_SUPPORTED_DEVICE(name)
......@@ -462,7 +464,10 @@ static inline local_t *__module_ref_addr(struct module *mod, int cpu)
static inline void __module_get(struct module *module)
{
if (module) {
local_inc(__module_ref_addr(module, get_cpu()));
unsigned int cpu = get_cpu();
local_inc(__module_ref_addr(module, cpu));
trace_module_get(module, _THIS_IP_,
local_read(__module_ref_addr(module, cpu)));
put_cpu();
}
}
......@@ -473,8 +478,11 @@ static inline int try_module_get(struct module *module)
if (module) {
unsigned int cpu = get_cpu();
if (likely(module_is_live(module)))
if (likely(module_is_live(module))) {
local_inc(__module_ref_addr(module, cpu));
trace_module_get(module, _THIS_IP_,
local_read(__module_ref_addr(module, cpu)));
}
else
ret = 0;
put_cpu();
......
#undef TRACE_SYSTEM
#define TRACE_SYSTEM module
#if !defined(_TRACE_MODULE_H) || defined(TRACE_HEADER_MULTI_READ)
#define _TRACE_MODULE_H
#include <linux/tracepoint.h>
#ifdef CONFIG_MODULES
struct module;
#define show_module_flags(flags) __print_flags(flags, "", \
{ (1UL << TAINT_PROPRIETARY_MODULE), "P" }, \
{ (1UL << TAINT_FORCED_MODULE), "F" }, \
{ (1UL << TAINT_CRAP), "C" })
TRACE_EVENT(module_load,
TP_PROTO(struct module *mod),
TP_ARGS(mod),
TP_STRUCT__entry(
__field( unsigned int, taints )
__string( name, mod->name )
),
TP_fast_assign(
__entry->taints = mod->taints;
__assign_str(name, mod->name);
),
TP_printk("%s %s", __get_str(name), show_module_flags(__entry->taints))
);
TRACE_EVENT(module_free,
TP_PROTO(struct module *mod),
TP_ARGS(mod),
TP_STRUCT__entry(
__string( name, mod->name )
),
TP_fast_assign(
__assign_str(name, mod->name);
),
TP_printk("%s", __get_str(name))
);
TRACE_EVENT(module_get,
TP_PROTO(struct module *mod, unsigned long ip, int refcnt),
TP_ARGS(mod, ip, refcnt),
TP_STRUCT__entry(
__field( unsigned long, ip )
__field( int, refcnt )
__string( name, mod->name )
),
TP_fast_assign(
__entry->ip = ip;
__entry->refcnt = refcnt;
__assign_str(name, mod->name);
),
TP_printk("%s call_site=%pf refcnt=%d",
__get_str(name), (void *)__entry->ip, __entry->refcnt)
);
TRACE_EVENT(module_put,
TP_PROTO(struct module *mod, unsigned long ip, int refcnt),
TP_ARGS(mod, ip, refcnt),
TP_STRUCT__entry(
__field( unsigned long, ip )
__field( int, refcnt )
__string( name, mod->name )
),
TP_fast_assign(
__entry->ip = ip;
__entry->refcnt = refcnt;
__assign_str(name, mod->name);
),
TP_printk("%s call_site=%pf refcnt=%d",
__get_str(name), (void *)__entry->ip, __entry->refcnt)
);
TRACE_EVENT(module_request,
TP_PROTO(char *name, bool wait, unsigned long ip),
TP_ARGS(name, wait, ip),
TP_STRUCT__entry(
__field( bool, wait )
__field( unsigned long, ip )
__string( name, name )
),
TP_fast_assign(
__entry->wait = wait;
__entry->ip = ip;
__assign_str(name, name);
),
TP_printk("%s wait=%d call_site=%pf",
__get_str(name), (int)__entry->wait, (void *)__entry->ip)
);
#endif /* CONFIG_MODULES */
#endif /* _TRACE_MODULE_H */
/* This part must be outside protection */
#include <trace/define_trace.h>
......@@ -37,6 +37,8 @@
#include <linux/suspend.h>
#include <asm/uaccess.h>
#include <trace/events/module.h>
extern int max_threads;
static struct workqueue_struct *khelper_wq;
......@@ -108,6 +110,8 @@ int __request_module(bool wait, const char *fmt, ...)
return -ENOMEM;
}
trace_module_request(module_name, wait, _RET_IP_);
ret = call_usermodehelper(modprobe_path, argv, envp,
wait ? UMH_WAIT_PROC : UMH_WAIT_EXEC);
atomic_dec(&kmod_concurrent);
......
......@@ -55,6 +55,11 @@
#include <linux/percpu.h>
#include <linux/kmemleak.h>
#define CREATE_TRACE_POINTS
#include <trace/events/module.h>
EXPORT_TRACEPOINT_SYMBOL(module_get);
#if 0
#define DEBUGP printk
#else
......@@ -940,6 +945,8 @@ void module_put(struct module *module)
if (module) {
unsigned int cpu = get_cpu();
local_dec(__module_ref_addr(module, cpu));
trace_module_put(module, _RET_IP_,
local_read(__module_ref_addr(module, cpu)));
/* Maybe they're waiting for us to drop reference? */
if (unlikely(!module_is_live(module)))
wake_up_process(module->waiter);
......@@ -1491,6 +1498,8 @@ static int __unlink_module(void *_mod)
/* Free a module, remove from lists, etc (must hold module_mutex). */
static void free_module(struct module *mod)
{
trace_module_free(mod);
/* Delete from various lists */
stop_machine(__unlink_module, mod, NULL);
remove_notes_attrs(mod);
......@@ -2358,6 +2367,8 @@ static noinline struct module *load_module(void __user *umod,
/* Get rid of temporary copy */
vfree(hdr);
trace_module_load(mod);
/* Done! */
return mod;
......
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