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authorChristoph Hellwig <hch@lst.de>2009-09-17 13:35:28 -0400
committerIngo Molnar <mingo@elte.hu>2009-09-18 15:22:08 -0400
commitfc5377668c3d808e1d53c4aee152c836f55c3490 (patch)
tree366723ccb26a64c311074c346721aaf4ff0e7d58
parentdf58bee21ed218cb7dfb561a590b1bd2a99531cf (diff)
tracing: Remove markers
Now that the last users of markers have migrated to the event tracer we can kill off the (now orphan) support code. Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> LKML-Reference: <20090917173527.GA1699@lst.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat
-rw-r--r--Documentation/markers.txt104
-rw-r--r--arch/powerpc/platforms/cell/spufs/file.c1
-rw-r--r--arch/powerpc/platforms/cell/spufs/sched.c1
-rw-r--r--include/linux/kvm_host.h1
-rw-r--r--include/linux/marker.h221
-rw-r--r--include/linux/module.h11
-rw-r--r--init/Kconfig7
-rw-r--r--kernel/Makefile1
-rw-r--r--kernel/marker.c930
-rw-r--r--kernel/module.c18
-rw-r--r--kernel/trace/trace_printk.c1
-rw-r--r--samples/Kconfig6
-rw-r--r--samples/Makefile2
-rw-r--r--samples/markers/Makefile4
-rw-r--r--samples/markers/marker-example.c53
-rw-r--r--samples/markers/probe-example.c92
-rw-r--r--scripts/Makefile.modpost12
17 files changed, 1 insertions, 1464 deletions
diff --git a/Documentation/markers.txt b/Documentation/markers.txt
deleted file mode 100644
index d2b3d0e91b26..000000000000
--- a/Documentation/markers.txt
+++ /dev/null
@@ -1,104 +0,0 @@
1 Using the Linux Kernel Markers
2
3 Mathieu Desnoyers
4
5
6This document introduces Linux Kernel Markers and their use. It provides
7examples of how to insert markers in the kernel and connect probe functions to
8them and provides some examples of probe functions.
9
10
11* Purpose of markers
12
13A marker placed in code provides a hook to call a function (probe) that you can
14provide at runtime. A marker can be "on" (a probe is connected to it) or "off"
15(no probe is attached). When a marker is "off" it has no effect, except for
16adding a tiny time penalty (checking a condition for a branch) and space
17penalty (adding a few bytes for the function call at the end of the
18instrumented function and adds a data structure in a separate section). When a
19marker is "on", the function you provide is called each time the marker is
20executed, in the execution context of the caller. When the function provided
21ends its execution, it returns to the caller (continuing from the marker site).
22
23You can put markers at important locations in the code. Markers are
24lightweight hooks that can pass an arbitrary number of parameters,
25described in a printk-like format string, to the attached probe function.
26
27They can be used for tracing and performance accounting.
28
29
30* Usage
31
32In order to use the macro trace_mark, you should include linux/marker.h.
33
34#include <linux/marker.h>
35
36And,
37
38trace_mark(subsystem_event, "myint %d mystring %s", someint, somestring);
39Where :
40- subsystem_event is an identifier unique to your event
41 - subsystem is the name of your subsystem.
42 - event is the name of the event to mark.
43- "myint %d mystring %s" is the formatted string for the serializer. "myint" and
44 "mystring" are repectively the field names associated with the first and
45 second parameter.
46- someint is an integer.
47- somestring is a char pointer.
48
49Connecting a function (probe) to a marker is done by providing a probe (function
50to call) for the specific marker through marker_probe_register() and can be
51activated by calling marker_arm(). Marker deactivation can be done by calling
52marker_disarm() as many times as marker_arm() has been called. Removing a probe
53is done through marker_probe_unregister(); it will disarm the probe.
54
55marker_synchronize_unregister() must be called between probe unregistration and
56the first occurrence of
57- the end of module exit function,
58 to make sure there is no caller left using the probe;
59- the free of any resource used by the probes,
60 to make sure the probes wont be accessing invalid data.
61This, and the fact that preemption is disabled around the probe call, make sure
62that probe removal and module unload are safe. See the "Probe example" section
63below for a sample probe module.
64
65The marker mechanism supports inserting multiple instances of the same marker.
66Markers can be put in inline functions, inlined static functions, and
67unrolled loops as well as regular functions.
68
69The naming scheme "subsystem_event" is suggested here as a convention intended
70to limit collisions. Marker names are global to the kernel: they are considered
71as being the same whether they are in the core kernel image or in modules.
72Conflicting format strings for markers with the same name will cause the markers
73to be detected to have a different format string not to be armed and will output
74a printk warning which identifies the inconsistency:
75
76"Format mismatch for probe probe_name (format), marker (format)"
77
78Another way to use markers is to simply define the marker without generating any
79function call to actually call into the marker. This is useful in combination
80with tracepoint probes in a scheme like this :
81
82void probe_tracepoint_name(unsigned int arg1, struct task_struct *tsk);
83
84DEFINE_MARKER_TP(marker_eventname, tracepoint_name, probe_tracepoint_name,
85 "arg1 %u pid %d");
86
87notrace void probe_tracepoint_name(unsigned int arg1, struct task_struct *tsk)
88{
89 struct marker *marker = &GET_MARKER(kernel_irq_entry);
90 /* write data to trace buffers ... */
91}
92
93* Probe / marker example
94
95See the example provided in samples/markers/src
96
97Compile them with your kernel.
98
99Run, as root :
100modprobe marker-example (insmod order is not important)
101modprobe probe-example
102cat /proc/marker-example (returns an expected error)
103rmmod marker-example probe-example
104dmesg
diff --git a/arch/powerpc/platforms/cell/spufs/file.c b/arch/powerpc/platforms/cell/spufs/file.c
index ab8aef9bb8ea..8f079b865ad0 100644
--- a/arch/powerpc/platforms/cell/spufs/file.c
+++ b/arch/powerpc/platforms/cell/spufs/file.c
@@ -29,7 +29,6 @@
29#include <linux/poll.h> 29#include <linux/poll.h>
30#include <linux/ptrace.h> 30#include <linux/ptrace.h>
31#include <linux/seq_file.h> 31#include <linux/seq_file.h>
32#include <linux/marker.h>
33 32
34#include <asm/io.h> 33#include <asm/io.h>
35#include <asm/time.h> 34#include <asm/time.h>
diff --git a/arch/powerpc/platforms/cell/spufs/sched.c b/arch/powerpc/platforms/cell/spufs/sched.c
index bb5b77c66d05..4678078fede8 100644
--- a/arch/powerpc/platforms/cell/spufs/sched.c
+++ b/arch/powerpc/platforms/cell/spufs/sched.c
@@ -39,7 +39,6 @@
39#include <linux/pid_namespace.h> 39#include <linux/pid_namespace.h>
40#include <linux/proc_fs.h> 40#include <linux/proc_fs.h>
41#include <linux/seq_file.h> 41#include <linux/seq_file.h>
42#include <linux/marker.h>
43 42
44#include <asm/io.h> 43#include <asm/io.h>
45#include <asm/mmu_context.h> 44#include <asm/mmu_context.h>
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 4af56036a6bf..b7bbb5ddd7ae 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -15,7 +15,6 @@
15#include <linux/sched.h> 15#include <linux/sched.h>
16#include <linux/mm.h> 16#include <linux/mm.h>
17#include <linux/preempt.h> 17#include <linux/preempt.h>
18#include <linux/marker.h>
19#include <linux/msi.h> 18#include <linux/msi.h>
20#include <asm/signal.h> 19#include <asm/signal.h>
21 20
diff --git a/include/linux/marker.h b/include/linux/marker.h
deleted file mode 100644
index b85e74ca782f..000000000000
--- a/include/linux/marker.h
+++ /dev/null
@@ -1,221 +0,0 @@
1#ifndef _LINUX_MARKER_H
2#define _LINUX_MARKER_H
3
4/*
5 * Code markup for dynamic and static tracing.
6 *
7 * See Documentation/marker.txt.
8 *
9 * (C) Copyright 2006 Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
10 *
11 * This file is released under the GPLv2.
12 * See the file COPYING for more details.
13 */
14
15#include <stdarg.h>
16#include <linux/types.h>
17
18struct module;
19struct marker;
20
21/**
22 * marker_probe_func - Type of a marker probe function
23 * @probe_private: probe private data
24 * @call_private: call site private data
25 * @fmt: format string
26 * @args: variable argument list pointer. Use a pointer to overcome C's
27 * inability to pass this around as a pointer in a portable manner in
28 * the callee otherwise.
29 *
30 * Type of marker probe functions. They receive the mdata and need to parse the
31 * format string to recover the variable argument list.
32 */
33typedef void marker_probe_func(void *probe_private, void *call_private,
34 const char *fmt, va_list *args);
35
36struct marker_probe_closure {
37 marker_probe_func *func; /* Callback */
38 void *probe_private; /* Private probe data */
39};
40
41struct marker {
42 const char *name; /* Marker name */
43 const char *format; /* Marker format string, describing the
44 * variable argument list.
45 */
46 char state; /* Marker state. */
47 char ptype; /* probe type : 0 : single, 1 : multi */
48 /* Probe wrapper */
49 void (*call)(const struct marker *mdata, void *call_private, ...);
50 struct marker_probe_closure single;
51 struct marker_probe_closure *multi;
52 const char *tp_name; /* Optional tracepoint name */
53 void *tp_cb; /* Optional tracepoint callback */
54} __attribute__((aligned(8)));
55
56#ifdef CONFIG_MARKERS
57
58#define _DEFINE_MARKER(name, tp_name_str, tp_cb, format) \
59 static const char __mstrtab_##name[] \
60 __attribute__((section("__markers_strings"))) \
61 = #name "\0" format; \
62 static struct marker __mark_##name \
63 __attribute__((section("__markers"), aligned(8))) = \
64 { __mstrtab_##name, &__mstrtab_##name[sizeof(#name)], \
65 0, 0, marker_probe_cb, { __mark_empty_function, NULL},\
66 NULL, tp_name_str, tp_cb }
67
68#define DEFINE_MARKER(name, format) \
69 _DEFINE_MARKER(name, NULL, NULL, format)
70
71#define DEFINE_MARKER_TP(name, tp_name, tp_cb, format) \
72 _DEFINE_MARKER(name, #tp_name, tp_cb, format)
73
74/*
75 * Note : the empty asm volatile with read constraint is used here instead of a
76 * "used" attribute to fix a gcc 4.1.x bug.
77 * Make sure the alignment of the structure in the __markers section will
78 * not add unwanted padding between the beginning of the section and the
79 * structure. Force alignment to the same alignment as the section start.
80 *
81 * The "generic" argument controls which marker enabling mechanism must be used.
82 * If generic is true, a variable read is used.
83 * If generic is false, immediate values are used.
84 */
85#define __trace_mark(generic, name, call_private, format, args...) \
86 do { \
87 DEFINE_MARKER(name, format); \
88 __mark_check_format(format, ## args); \
89 if (unlikely(__mark_##name.state)) { \
90 (*__mark_##name.call) \
91 (&__mark_##name, call_private, ## args);\
92 } \
93 } while (0)
94
95#define __trace_mark_tp(name, call_private, tp_name, tp_cb, format, args...) \
96 do { \
97 void __check_tp_type(void) \
98 { \
99 register_trace_##tp_name(tp_cb); \
100 } \
101 DEFINE_MARKER_TP(name, tp_name, tp_cb, format); \
102 __mark_check_format(format, ## args); \
103 (*__mark_##name.call)(&__mark_##name, call_private, \
104 ## args); \
105 } while (0)
106
107extern void marker_update_probe_range(struct marker *begin,
108 struct marker *end);
109
110#define GET_MARKER(name) (__mark_##name)
111
112#else /* !CONFIG_MARKERS */
113#define DEFINE_MARKER(name, tp_name, tp_cb, format)
114#define __trace_mark(generic, name, call_private, format, args...) \
115 __mark_check_format(format, ## args)
116#define __trace_mark_tp(name, call_private, tp_name, tp_cb, format, args...) \
117 do { \
118 void __check_tp_type(void) \
119 { \
120 register_trace_##tp_name(tp_cb); \
121 } \
122 __mark_check_format(format, ## args); \
123 } while (0)
124static inline void marker_update_probe_range(struct marker *begin,
125 struct marker *end)
126{ }
127#define GET_MARKER(name)
128#endif /* CONFIG_MARKERS */
129
130/**
131 * trace_mark - Marker using code patching
132 * @name: marker name, not quoted.
133 * @format: format string
134 * @args...: variable argument list
135 *
136 * Places a marker using optimized code patching technique (imv_read())
137 * to be enabled when immediate values are present.
138 */
139#define trace_mark(name, format, args...) \
140 __trace_mark(0, name, NULL, format, ## args)
141
142/**
143 * _trace_mark - Marker using variable read
144 * @name: marker name, not quoted.
145 * @format: format string
146 * @args...: variable argument list
147 *
148 * Places a marker using a standard memory read (_imv_read()) to be
149 * enabled. Should be used for markers in code paths where instruction
150 * modification based enabling is not welcome. (__init and __exit functions,
151 * lockdep, some traps, printk).
152 */
153#define _trace_mark(name, format, args...) \
154 __trace_mark(1, name, NULL, format, ## args)
155
156/**
157 * trace_mark_tp - Marker in a tracepoint callback
158 * @name: marker name, not quoted.
159 * @tp_name: tracepoint name, not quoted.
160 * @tp_cb: tracepoint callback. Should have an associated global symbol so it
161 * is not optimized away by the compiler (should not be static).
162 * @format: format string
163 * @args...: variable argument list
164 *
165 * Places a marker in a tracepoint callback.
166 */
167#define trace_mark_tp(name, tp_name, tp_cb, format, args...) \
168 __trace_mark_tp(name, NULL, tp_name, tp_cb, format, ## args)
169
170/**
171 * MARK_NOARGS - Format string for a marker with no argument.
172 */
173#define MARK_NOARGS " "
174
175/* To be used for string format validity checking with gcc */
176static inline void __printf(1, 2) ___mark_check_format(const char *fmt, ...)
177{
178}
179
180#define __mark_check_format(format, args...) \
181 do { \
182 if (0) \
183 ___mark_check_format(format, ## args); \
184 } while (0)
185
186extern marker_probe_func __mark_empty_function;
187
188extern void marker_probe_cb(const struct marker *mdata,
189 void *call_private, ...);
190
191/*
192 * Connect a probe to a marker.
193 * private data pointer must be a valid allocated memory address, or NULL.
194 */
195extern int marker_probe_register(const char *name, const char *format,
196 marker_probe_func *probe, void *probe_private);
197
198/*
199 * Returns the private data given to marker_probe_register.
200 */
201extern int marker_probe_unregister(const char *name,
202 marker_probe_func *probe, void *probe_private);
203/*
204 * Unregister a marker by providing the registered private data.
205 */
206extern int marker_probe_unregister_private_data(marker_probe_func *probe,
207 void *probe_private);
208
209extern void *marker_get_private_data(const char *name, marker_probe_func *probe,
210 int num);
211
212/*
213 * marker_synchronize_unregister must be called between the last marker probe
214 * unregistration and the first one of
215 * - the end of module exit function
216 * - the free of any resource used by the probes
217 * to ensure the code and data are valid for any possibly running probes.
218 */
219#define marker_synchronize_unregister() synchronize_sched()
220
221#endif
diff --git a/include/linux/module.h b/include/linux/module.h
index f8f92d015efe..1c755b2f937d 100644
--- a/include/linux/module.h
+++ b/include/linux/module.h
@@ -15,7 +15,6 @@
15#include <linux/stringify.h> 15#include <linux/stringify.h>
16#include <linux/kobject.h> 16#include <linux/kobject.h>
17#include <linux/moduleparam.h> 17#include <linux/moduleparam.h>
18#include <linux/marker.h>
19#include <linux/tracepoint.h> 18#include <linux/tracepoint.h>
20 19
21#include <asm/local.h> 20#include <asm/local.h>
@@ -327,10 +326,6 @@ struct module
327 /* The command line arguments (may be mangled). People like 326 /* The command line arguments (may be mangled). People like
328 keeping pointers to this stuff */ 327 keeping pointers to this stuff */
329 char *args; 328 char *args;
330#ifdef CONFIG_MARKERS
331 struct marker *markers;
332 unsigned int num_markers;
333#endif
334#ifdef CONFIG_TRACEPOINTS 329#ifdef CONFIG_TRACEPOINTS
335 struct tracepoint *tracepoints; 330 struct tracepoint *tracepoints;
336 unsigned int num_tracepoints; 331 unsigned int num_tracepoints;
@@ -535,8 +530,6 @@ int unregister_module_notifier(struct notifier_block * nb);
535 530
536extern void print_modules(void); 531extern void print_modules(void);
537 532
538extern void module_update_markers(void);
539
540extern void module_update_tracepoints(void); 533extern void module_update_tracepoints(void);
541extern int module_get_iter_tracepoints(struct tracepoint_iter *iter); 534extern int module_get_iter_tracepoints(struct tracepoint_iter *iter);
542 535
@@ -651,10 +644,6 @@ static inline void print_modules(void)
651{ 644{
652} 645}
653 646
654static inline void module_update_markers(void)
655{
656}
657
658static inline void module_update_tracepoints(void) 647static inline void module_update_tracepoints(void)
659{ 648{
660} 649}
diff --git a/init/Kconfig b/init/Kconfig
index 8e8b76d8a272..4cc0fa13d5eb 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -1054,13 +1054,6 @@ config PROFILING
1054config TRACEPOINTS 1054config TRACEPOINTS
1055 bool 1055 bool
1056 1056
1057config MARKERS
1058 bool "Activate markers"
1059 select TRACEPOINTS
1060 help
1061 Place an empty function call at each marker site. Can be
1062 dynamically changed for a probe function.
1063
1064source "arch/Kconfig" 1057source "arch/Kconfig"
1065 1058
1066config SLOW_WORK 1059config SLOW_WORK
diff --git a/kernel/Makefile b/kernel/Makefile
index 3d9c7e27e3f9..7c9b0a585502 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -87,7 +87,6 @@ obj-$(CONFIG_RELAY) += relay.o
87obj-$(CONFIG_SYSCTL) += utsname_sysctl.o 87obj-$(CONFIG_SYSCTL) += utsname_sysctl.o
88obj-$(CONFIG_TASK_DELAY_ACCT) += delayacct.o 88obj-$(CONFIG_TASK_DELAY_ACCT) += delayacct.o
89obj-$(CONFIG_TASKSTATS) += taskstats.o tsacct.o 89obj-$(CONFIG_TASKSTATS) += taskstats.o tsacct.o
90obj-$(CONFIG_MARKERS) += marker.o
91obj-$(CONFIG_TRACEPOINTS) += tracepoint.o 90obj-$(CONFIG_TRACEPOINTS) += tracepoint.o
92obj-$(CONFIG_LATENCYTOP) += latencytop.o 91obj-$(CONFIG_LATENCYTOP) += latencytop.o
93obj-$(CONFIG_FUNCTION_TRACER) += trace/ 92obj-$(CONFIG_FUNCTION_TRACER) += trace/
diff --git a/kernel/marker.c b/kernel/marker.c
deleted file mode 100644
index ea54f2647868..000000000000
--- a/kernel/marker.c
+++ /dev/null
@@ -1,930 +0,0 @@
1/*
2 * Copyright (C) 2007 Mathieu Desnoyers
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation; either version 2 of the License, or
7 * (at your option) any later version.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
17 */
18#include <linux/module.h>
19#include <linux/mutex.h>
20#include <linux/types.h>
21#include <linux/jhash.h>
22#include <linux/list.h>
23#include <linux/rcupdate.h>
24#include <linux/marker.h>
25#include <linux/err.h>
26#include <linux/slab.h>
27
28extern struct marker __start___markers[];
29extern struct marker __stop___markers[];
30
31/* Set to 1 to enable marker debug output */
32static const int marker_debug;
33
34/*
35 * markers_mutex nests inside module_mutex. Markers mutex protects the builtin
36 * and module markers and the hash table.
37 */
38static DEFINE_MUTEX(markers_mutex);
39
40/*
41 * Marker hash table, containing the active markers.
42 * Protected by module_mutex.
43 */
44#define MARKER_HASH_BITS 6
45#define MARKER_TABLE_SIZE (1 << MARKER_HASH_BITS)
46static struct hlist_head marker_table[MARKER_TABLE_SIZE];
47
48/*
49 * Note about RCU :
50 * It is used to make sure every handler has finished using its private data
51 * between two consecutive operation (add or remove) on a given marker. It is
52 * also used to delay the free of multiple probes array until a quiescent state
53 * is reached.
54 * marker entries modifications are protected by the markers_mutex.
55 */
56struct marker_entry {
57 struct hlist_node hlist;
58 char *format;
59 /* Probe wrapper */
60 void (*call)(const struct marker *mdata, void *call_private, ...);
61 struct marker_probe_closure single;
62 struct marker_probe_closure *multi;
63 int refcount; /* Number of times armed. 0 if disarmed. */
64 struct rcu_head rcu;
65 void *oldptr;
66 int rcu_pending;
67 unsigned char ptype:1;
68 unsigned char format_allocated:1;
69 char name[0]; /* Contains name'\0'format'\0' */
70};
71
72/**
73 * __mark_empty_function - Empty probe callback
74 * @probe_private: probe private data
75 * @call_private: call site private data
76 * @fmt: format string
77 * @...: variable argument list
78 *
79 * Empty callback provided as a probe to the markers. By providing this to a
80 * disabled marker, we make sure the execution flow is always valid even
81 * though the function pointer change and the marker enabling are two distinct
82 * operations that modifies the execution flow of preemptible code.
83 */
84notrace void __mark_empty_function(void *probe_private, void *call_private,
85 const char *fmt, va_list *args)
86{
87}
88EXPORT_SYMBOL_GPL(__mark_empty_function);
89
90/*
91 * marker_probe_cb Callback that prepares the variable argument list for probes.
92 * @mdata: pointer of type struct marker
93 * @call_private: caller site private data
94 * @...: Variable argument list.
95 *
96 * Since we do not use "typical" pointer based RCU in the 1 argument case, we
97 * need to put a full smp_rmb() in this branch. This is why we do not use
98 * rcu_dereference() for the pointer read.
99 */
100notrace void marker_probe_cb(const struct marker *mdata,
101 void *call_private, ...)
102{
103 va_list args;
104 char ptype;
105
106 /*
107 * rcu_read_lock_sched does two things : disabling preemption to make
108 * sure the teardown of the callbacks can be done correctly when they
109 * are in modules and they insure RCU read coherency.
110 */
111 rcu_read_lock_sched_notrace();
112 ptype = mdata->ptype;
113 if (likely(!ptype)) {
114 marker_probe_func *func;
115 /* Must read the ptype before ptr. They are not data dependant,
116 * so we put an explicit smp_rmb() here. */
117 smp_rmb();
118 func = mdata->single.func;
119 /* Must read the ptr before private data. They are not data
120 * dependant, so we put an explicit smp_rmb() here. */
121 smp_rmb();
122 va_start(args, call_private);
123 func(mdata->single.probe_private, call_private, mdata->format,
124 &args);
125 va_end(args);
126 } else {
127 struct marker_probe_closure *multi;
128 int i;
129 /*
130 * Read mdata->ptype before mdata->multi.
131 */
132 smp_rmb();
133 multi = mdata->multi;
134 /*
135 * multi points to an array, therefore accessing the array
136 * depends on reading multi. However, even in this case,
137 * we must insure that the pointer is read _before_ the array
138 * data. Same as rcu_dereference, but we need a full smp_rmb()
139 * in the fast path, so put the explicit barrier here.
140 */
141 smp_read_barrier_depends();
142 for (i = 0; multi[i].func; i++) {
143 va_start(args, call_private);
144 multi[i].func(multi[i].probe_private, call_private,
145 mdata->format, &args);
146 va_end(args);
147 }
148 }
149 rcu_read_unlock_sched_notrace();
150}
151EXPORT_SYMBOL_GPL(marker_probe_cb);
152
153/*
154 * marker_probe_cb Callback that does not prepare the variable argument list.
155 * @mdata: pointer of type struct marker
156 * @call_private: caller site private data
157 * @...: Variable argument list.
158 *
159 * Should be connected to markers "MARK_NOARGS".
160 */
161static notrace void marker_probe_cb_noarg(const struct marker *mdata,
162 void *call_private, ...)
163{
164 va_list args; /* not initialized */
165 char ptype;
166
167 rcu_read_lock_sched_notrace();
168 ptype = mdata->ptype;
169 if (likely(!ptype)) {
170 marker_probe_func *func;
171 /* Must read the ptype before ptr. They are not data dependant,
172 * so we put an explicit smp_rmb() here. */
173 smp_rmb();
174 func = mdata->single.func;
175 /* Must read the ptr before private data. They are not data
176 * dependant, so we put an explicit smp_rmb() here. */
177 smp_rmb();
178 func(mdata->single.probe_private, call_private, mdata->format,
179 &args);
180 } else {
181 struct marker_probe_closure *multi;
182 int i;
183 /*
184 * Read mdata->ptype before mdata->multi.
185 */
186 smp_rmb();
187 multi = mdata->multi;
188 /*
189 * multi points to an array, therefore accessing the array
190 * depends on reading multi. However, even in this case,
191 * we must insure that the pointer is read _before_ the array
192 * data. Same as rcu_dereference, but we need a full smp_rmb()
193 * in the fast path, so put the explicit barrier here.
194 */
195 smp_read_barrier_depends();
196 for (i = 0; multi[i].func; i++)
197 multi[i].func(multi[i].probe_private, call_private,
198 mdata->format, &args);
199 }
200 rcu_read_unlock_sched_notrace();
201}
202
203static void free_old_closure(struct rcu_head *head)
204{
205 struct marker_entry *entry = container_of(head,
206 struct marker_entry, rcu);
207 kfree(entry->oldptr);
208 /* Make sure we free the data before setting the pending flag to 0 */
209 smp_wmb();
210 entry->rcu_pending = 0;
211}
212
213static void debug_print_probes(struct marker_entry *entry)
214{
215 int i;
216
217 if (!marker_debug)
218 return;
219
220 if (!entry->ptype) {
221 printk(KERN_DEBUG "Single probe : %p %p\n",
222 entry->single.func,
223 entry->single.probe_private);
224 } else {
225 for (i = 0; entry->multi[i].func; i++)
226 printk(KERN_DEBUG "Multi probe %d : %p %p\n", i,
227 entry->multi[i].func,
228 entry->multi[i].probe_private);
229 }
230}
231
232static struct marker_probe_closure *
233marker_entry_add_probe(struct marker_entry *entry,
234 marker_probe_func *probe, void *probe_private)
235{
236 int nr_probes = 0;
237 struct marker_probe_closure *old, *new;
238
239 WARN_ON(!probe);
240
241 debug_print_probes(entry);
242 old = entry->multi;
243 if (!entry->ptype) {
244 if (entry->single.func == probe &&
245 entry->single.probe_private == probe_private)
246 return ERR_PTR(-EBUSY);
247 if (entry->single.func == __mark_empty_function) {
248 /* 0 -> 1 probes */
249 entry->single.func = probe;
250 entry->single.probe_private = probe_private;
251 entry->refcount = 1;
252 entry->ptype = 0;
253 debug_print_probes(entry);
254 return NULL;
255 } else {
256 /* 1 -> 2 probes */
257 nr_probes = 1;
258 old = NULL;
259 }
260 } else {
261 /* (N -> N+1), (N != 0, 1) probes */
262 for (nr_probes = 0; old[nr_probes].func; nr_probes++)
263 if (old[nr_probes].func == probe
264 && old[nr_probes].probe_private
265 == probe_private)
266 return ERR_PTR(-EBUSY);
267 }
268 /* + 2 : one for new probe, one for NULL func */
269 new = kzalloc((nr_probes + 2) * sizeof(struct marker_probe_closure),
270 GFP_KERNEL);
271 if (new == NULL)
272 return ERR_PTR(-ENOMEM);
273 if (!old)
274 new[0] = entry->single;
275 else
276 memcpy(new, old,
277 nr_probes * sizeof(struct marker_probe_closure));
278 new[nr_probes].func = probe;
279 new[nr_probes].probe_private = probe_private;
280 entry->refcount = nr_probes + 1;
281 entry->multi = new;
282 entry->ptype = 1;
283 debug_print_probes(entry);
284 return old;
285}
286
287static struct marker_probe_closure *
288marker_entry_remove_probe(struct marker_entry *entry,
289 marker_probe_func *probe, void *probe_private)
290{
291 int nr_probes = 0, nr_del = 0, i;
292 struct marker_probe_closure *old, *new;
293
294 old = entry->multi;
295
296 debug_print_probes(entry);
297 if (!entry->ptype) {
298 /* 0 -> N is an error */
299 WARN_ON(entry->single.func == __mark_empty_function);
300 /* 1 -> 0 probes */
301 WARN_ON(probe && entry->single.func != probe);
302 WARN_ON(entry->single.probe_private != probe_private);
303 entry->single.func = __mark_empty_function;
304 entry->refcount = 0;
305 entry->ptype = 0;
306 debug_print_probes(entry);
307 return NULL;
308 } else {
309 /* (N -> M), (N > 1, M >= 0) probes */
310 for (nr_probes = 0; old[nr_probes].func; nr_probes++) {
311 if ((!probe || old[nr_probes].func == probe)
312 && old[nr_probes].probe_private
313 == probe_private)
314 nr_del++;
315 }
316 }
317
318 if (nr_probes - nr_del == 0) {
319 /* N -> 0, (N > 1) */
320 entry->single.func = __mark_empty_function;
321 entry->refcount = 0;
322 entry->ptype = 0;
323 } else if (nr_probes - nr_del == 1) {
324 /* N -> 1, (N > 1) */
325 for (i = 0; old[i].func; i++)
326 if ((probe && old[i].func != probe) ||
327 old[i].probe_private != probe_private)
328 entry->single = old[i];
329 entry->refcount = 1;
330 entry->ptype = 0;
331 } else {
332 int j = 0;
333 /* N -> M, (N > 1, M > 1) */
334 /* + 1 for NULL */
335 new = kzalloc((nr_probes - nr_del + 1)
336 * sizeof(struct marker_probe_closure), GFP_KERNEL);
337 if (new == NULL)
338 return ERR_PTR(-ENOMEM);
339 for (i = 0; old[i].func; i++)
340 if ((probe && old[i].func != probe) ||
341 old[i].probe_private != probe_private)
342 new[j++] = old[i];
343 entry->refcount = nr_probes - nr_del;
344 entry->ptype = 1;
345 entry->multi = new;
346 }
347 debug_print_probes(entry);
348 return old;
349}
350
351/*
352 * Get marker if the marker is present in the marker hash table.
353 * Must be called with markers_mutex held.
354 * Returns NULL if not present.
355 */
356static struct marker_entry *get_marker(const char *name)
357{
358 struct hlist_head *head;
359 struct hlist_node *node;
360 struct marker_entry *e;
361 u32 hash = jhash(name, strlen(name), 0);
362
363 head = &marker_table[hash & ((1 << MARKER_HASH_BITS)-1)];
364 hlist_for_each_entry(e, node, head, hlist) {
365 if (!strcmp(name, e->name))
366 return e;
367 }
368 return NULL;
369}
370
371/*
372 * Add the marker to the marker hash table. Must be called with markers_mutex
373 * held.
374 */
375static struct marker_entry *add_marker(const char *name, const char *format)
376{
377 struct hlist_head *head;
378 struct hlist_node *node;
379 struct marker_entry *e;
380 size_t name_len = strlen(name) + 1;
381 size_t format_len = 0;
382 u32 hash = jhash(name, name_len-1, 0);
383
384 if (format)
385 format_len = strlen(format) + 1;
386 head = &marker_table[hash & ((1 << MARKER_HASH_BITS)-1)];
387 hlist_for_each_entry(e, node, head, hlist) {
388 if (!strcmp(name, e->name)) {
389 printk(KERN_NOTICE
390 "Marker %s busy\n", name);
391 return ERR_PTR(-EBUSY); /* Already there */
392 }
393 }
394 /*
395 * Using kmalloc here to allocate a variable length element. Could
396 * cause some memory fragmentation if overused.
397 */
398 e = kmalloc(sizeof(struct marker_entry) + name_len + format_len,
399 GFP_KERNEL);
400 if (!e)
401 return ERR_PTR(-ENOMEM);
402 memcpy(&e->name[0], name, name_len);
403 if (format) {
404 e->format = &e->name[name_len];
405 memcpy(e->format, format, format_len);
406 if (strcmp(e->format, MARK_NOARGS) == 0)
407 e->call = marker_probe_cb_noarg;
408 else
409 e->call = marker_probe_cb;
410 trace_mark(core_marker_format, "name %s format %s",
411 e->name, e->format);
412 } else {
413 e->format = NULL;
414 e->call = marker_probe_cb;
415 }
416 e->single.func = __mark_empty_function;
417 e->single.probe_private = NULL;
418 e->multi = NULL;
419 e->ptype = 0;
420 e->format_allocated = 0;
421 e->refcount = 0;
422 e->rcu_pending = 0;
423 hlist_add_head(&e->hlist, head);
424 return e;
425}
426
427/*
428 * Remove the marker from the marker hash table. Must be called with mutex_lock
429 * held.
430 */
431static int remove_marker(const char *name)
432{
433 struct hlist_head *head;
434 struct hlist_node *node;
435 struct marker_entry *e;
436 int found = 0;
437 size_t len = strlen(name) + 1;
438 u32 hash = jhash(name, len-1, 0);
439
440 head = &marker_table[hash & ((1 << MARKER_HASH_BITS)-1)];
441 hlist_for_each_entry(e, node, head, hlist) {
442 if (!strcmp(name, e->name)) {
443 found = 1;
444 break;
445 }
446 }
447 if (!found)
448 return -ENOENT;
449 if (e->single.func != __mark_empty_function)
450 return -EBUSY;
451 hlist_del(&e->hlist);
452 if (e->format_allocated)
453 kfree(e->format);
454 /* Make sure the call_rcu has been executed */
455 if (e->rcu_pending)
456 rcu_barrier_sched();
457 kfree(e);
458 return 0;
459}
460
461/*
462 * Set the mark_entry format to the format found in the element.
463 */
464static int marker_set_format(struct marker_entry *entry, const char *format)
465{
466 entry->format = kstrdup(format, GFP_KERNEL);
467 if (!entry->format)
468 return -ENOMEM;
469 entry->format_allocated = 1;
470
471 trace_mark(core_marker_format, "name %s format %s",
472 entry->name, entry->format);
473 return 0;
474}
475
476/*
477 * Sets the probe callback corresponding to one marker.
478 */
479static int set_marker(struct marker_entry *entry, struct marker *elem,
480 int active)
481{
482 int ret = 0;
483 WARN_ON(strcmp(entry->name, elem->name) != 0);
484
485 if (entry->format) {
486 if (strcmp(entry->format, elem->format) != 0) {
487 printk(KERN_NOTICE
488 "Format mismatch for probe %s "
489 "(%s), marker (%s)\n",
490 entry->name,
491 entry->format,
492 elem->format);
493 return -EPERM;
494 }
495 } else {
496 ret = marker_set_format(entry, elem->format);
497 if (ret)
498 return ret;
499 }
500
501 /*
502 * probe_cb setup (statically known) is done here. It is
503 * asynchronous with the rest of execution, therefore we only
504 * pass from a "safe" callback (with argument) to an "unsafe"
505 * callback (does not set arguments).
506 */
507 elem->call = entry->call;
508 /*
509 * Sanity check :
510 * We only update the single probe private data when the ptr is
511 * set to a _non_ single probe! (0 -> 1 and N -> 1, N != 1)
512 */
513 WARN_ON(elem->single.func != __mark_empty_function
514 && elem->single.probe_private != entry->single.probe_private
515 && !elem->ptype);
516 elem->single.probe_private = entry->single.probe_private;
517 /*
518 * Make sure the private data is valid when we update the
519 * single probe ptr.
520 */
521 smp_wmb();
522 elem->single.func = entry->single.func;
523 /*
524 * We also make sure that the new probe callbacks array is consistent
525 * before setting a pointer to it.
526 */
527 rcu_assign_pointer(elem->multi, entry->multi);
528 /*
529 * Update the function or multi probe array pointer before setting the
530 * ptype.
531 */
532 smp_wmb();
533 elem->ptype = entry->ptype;
534
535 if (elem->tp_name && (active ^ elem->state)) {
536 WARN_ON(!elem->tp_cb);
537 /*
538 * It is ok to directly call the probe registration because type
539 * checking has been done in the __trace_mark_tp() macro.
540 */
541
542 if (active) {
543 /*
544 * try_module_get should always succeed because we hold
545 * lock_module() to get the tp_cb address.
546 */
547 ret = try_module_get(__module_text_address(
548 (unsigned long)elem->tp_cb));
549 BUG_ON(!ret);
550 ret = tracepoint_probe_register_noupdate(
551 elem->tp_name,
552 elem->tp_cb);
553 } else {
554 ret = tracepoint_probe_unregister_noupdate(
555 elem->tp_name,
556 elem->tp_cb);
557 /*
558 * tracepoint_probe_update_all() must be called
559 * before the module containing tp_cb is unloaded.
560 */
561 module_put(__module_text_address(
562 (unsigned long)elem->tp_cb));
563 }
564 }
565 elem->state = active;
566
567 return ret;
568}
569
570/*
571 * Disable a marker and its probe callback.
572 * Note: only waiting an RCU period after setting elem->call to the empty
573 * function insures that the original callback is not used anymore. This insured
574 * by rcu_read_lock_sched around the call site.
575 */
576static void disable_marker(struct marker *elem)
577{
578 int ret;
579
580 /* leave "call" as is. It is known statically. */
581 if (elem->tp_name && elem->state) {
582 WARN_ON(!elem->tp_cb);
583 /*
584 * It is ok to directly call the probe registration because type
585 * checking has been done in the __trace_mark_tp() macro.
586 */
587 ret = tracepoint_probe_unregister_noupdate(elem->tp_name,
588 elem->tp_cb);
589 WARN_ON(ret);
590 /*
591 * tracepoint_probe_update_all() must be called
592 * before the module containing tp_cb is unloaded.
593 */
594 module_put(__module_text_address((unsigned long)elem->tp_cb));
595 }
596 elem->state = 0;
597 elem->single.func = __mark_empty_function;
598 /* Update the function before setting the ptype */
599 smp_wmb();
600 elem->ptype = 0; /* single probe */
601 /*
602 * Leave the private data and id there, because removal is racy and
603 * should be done only after an RCU period. These are never used until
604 * the next initialization anyway.
605 */
606}
607
608/**
609 * marker_update_probe_range - Update a probe range
610 * @begin: beginning of the range
611 * @end: end of the range
612 *
613 * Updates the probe callback corresponding to a range of markers.
614 */
615void marker_update_probe_range(struct marker *begin,
616 struct marker *end)
617{
618 struct marker *iter;
619 struct marker_entry *mark_entry;
620
621 mutex_lock(&markers_mutex);
622 for (iter = begin; iter < end; iter++) {
623 mark_entry = get_marker(iter->name);
624 if (mark_entry) {
625 set_marker(mark_entry, iter, !!mark_entry->refcount);
626 /*
627 * ignore error, continue
628 */
629 } else {
630 disable_marker(iter);
631 }
632 }
633 mutex_unlock(&markers_mutex);
634}
635
636/*
637 * Update probes, removing the faulty probes.
638 *
639 * Internal callback only changed before the first probe is connected to it.
640 * Single probe private data can only be changed on 0 -> 1 and 2 -> 1
641 * transitions. All other transitions will leave the old private data valid.
642 * This makes the non-atomicity of the callback/private data updates valid.
643 *
644 * "special case" updates :
645 * 0 -> 1 callback
646 * 1 -> 0 callback
647 * 1 -> 2 callbacks
648 * 2 -> 1 callbacks
649 * Other updates all behave the same, just like the 2 -> 3 or 3 -> 2 updates.
650 * Site effect : marker_set_format may delete the marker entry (creating a
651 * replacement).
652 */
653static void marker_update_probes(void)
654{
655 /* Core kernel markers */
656 marker_update_probe_range(__start___markers, __stop___markers);
657 /* Markers in modules. */
658 module_update_markers();
659 tracepoint_probe_update_all();
660}
661
662/**
663 * marker_probe_register - Connect a probe to a marker
664 * @name: marker name
665 * @format: format string
666 * @probe: probe handler
667 * @probe_private: probe private data
668 *
669 * private data must be a valid allocated memory address, or NULL.
670 * Returns 0 if ok, error value on error.
671 * The probe address must at least be aligned on the architecture pointer size.
672 */
673int marker_probe_register(const char *name, const char *format,
674 marker_probe_func *probe, void *probe_private)
675{
676 struct marker_entry *entry;
677 int ret = 0;
678 struct marker_probe_closure *old;
679
680 mutex_lock(&markers_mutex);
681 entry = get_marker(name);
682 if (!entry) {
683 entry = add_marker(name, format);
684 if (IS_ERR(entry))
685 ret = PTR_ERR(entry);
686 } else if (format) {
687 if (!entry->format)
688 ret = marker_set_format(entry, format);
689 else if (strcmp(entry->format, format))
690 ret = -EPERM;
691 }
692 if (ret)
693 goto end;
694
695 /*
696 * If we detect that a call_rcu is pending for this marker,
697 * make sure it's executed now.
698 */
699 if (entry->rcu_pending)
700 rcu_barrier_sched();
701 old = marker_entry_add_probe(entry, probe, probe_private);
702 if (IS_ERR(old)) {
703 ret = PTR_ERR(old);
704 goto end;
705 }
706 mutex_unlock(&markers_mutex);
707 marker_update_probes();
708 mutex_lock(&markers_mutex);
709 entry = get_marker(name);
710 if (!entry)
711 goto end;
712 if (entry->rcu_pending)
713 rcu_barrier_sched();
714 entry->oldptr = old;
715 entry->rcu_pending = 1;
716 /* write rcu_pending before calling the RCU callback */
717 smp_wmb();
718 call_rcu_sched(&entry->rcu, free_old_closure);
719end:
720 mutex_unlock(&markers_mutex);
721 return ret;
722}
723EXPORT_SYMBOL_GPL(marker_probe_register);
724
725/**
726 * marker_probe_unregister - Disconnect a probe from a marker
727 * @name: marker name
728 * @probe: probe function pointer
729 * @probe_private: probe private data
730 *
731 * Returns the private data given to marker_probe_register, or an ERR_PTR().
732 * We do not need to call a synchronize_sched to make sure the probes have
733 * finished running before doing a module unload, because the module unload
734 * itself uses stop_machine(), which insures that every preempt disabled section
735 * have finished.
736 */
737int marker_probe_unregister(const char *name,
738 marker_probe_func *probe, void *probe_private)
739{
740 struct marker_entry *entry;
741 struct marker_probe_closure *old;
742 int ret = -ENOENT;
743
744 mutex_lock(&markers_mutex);
745 entry = get_marker(name);
746 if (!entry)
747 goto end;
748 if (entry->rcu_pending)
749 rcu_barrier_sched();
750 old = marker_entry_remove_probe(entry, probe, probe_private);
751 mutex_unlock(&markers_mutex);
752 marker_update_probes();
753 mutex_lock(&markers_mutex);
754 entry = get_marker(name);
755 if (!entry)
756 goto end;
757 if (entry->rcu_pending)
758 rcu_barrier_sched();
759 entry->oldptr = old;
760 entry->rcu_pending = 1;
761 /* write rcu_pending before calling the RCU callback */
762 smp_wmb();
763 call_rcu_sched(&entry->rcu, free_old_closure);
764 remove_marker(name); /* Ignore busy error message */
765 ret = 0;
766end:
767 mutex_unlock(&markers_mutex);
768 return ret;
769}
770EXPORT_SYMBOL_GPL(marker_probe_unregister);
771
772static struct marker_entry *
773get_marker_from_private_data(marker_probe_func *probe, void *probe_private)
774{
775 struct marker_entry *entry;
776 unsigned int i;
777 struct hlist_head *head;
778 struct hlist_node *node;
779
780 for (i = 0; i < MARKER_TABLE_SIZE; i++) {
781 head = &marker_table[i];
782 hlist_for_each_entry(entry, node, head, hlist) {
783 if (!entry->ptype) {
784 if (entry->single.func == probe
785 && entry->single.probe_private
786 == probe_private)
787 return entry;
788 } else {
789 struct marker_probe_closure *closure;
790 closure = entry->multi;
791 for (i = 0; closure[i].func; i++) {
792 if (closure[i].func == probe &&
793 closure[i].probe_private
794 == probe_private)
795 return entry;
796 }
797 }
798 }
799 }
800 return NULL;
801}
802
803/**
804 * marker_probe_unregister_private_data - Disconnect a probe from a marker
805 * @probe: probe function
806 * @probe_private: probe private data
807 *
808 * Unregister a probe by providing the registered private data.
809 * Only removes the first marker found in hash table.
810 * Return 0 on success or error value.
811 * We do not need to call a synchronize_sched to make sure the probes have
812 * finished running before doing a module unload, because the module unload
813 * itself uses stop_machine(), which insures that every preempt disabled section
814 * have finished.
815 */
816int marker_probe_unregister_private_data(marker_probe_func *probe,
817 void *probe_private)
818{
819 struct marker_entry *entry;
820 int ret = 0;
821 struct marker_probe_closure *old;
822
823 mutex_lock(&markers_mutex);
824 entry = get_marker_from_private_data(probe, probe_private);
825 if (!entry) {
826 ret = -ENOENT;
827 goto end;
828 }
829 if (entry->rcu_pending)
830 rcu_barrier_sched();
831 old = marker_entry_remove_probe(entry, NULL, probe_private);
832 mutex_unlock(&markers_mutex);
833 marker_update_probes();
834 mutex_lock(&markers_mutex);
835 entry = get_marker_from_private_data(probe, probe_private);
836 if (!entry)
837 goto end;
838 if (entry->rcu_pending)
839 rcu_barrier_sched();
840 entry->oldptr = old;
841 entry->rcu_pending = 1;
842 /* write rcu_pending before calling the RCU callback */
843 smp_wmb();
844 call_rcu_sched(&entry->rcu, free_old_closure);
845 remove_marker(entry->name); /* Ignore busy error message */
846end:
847 mutex_unlock(&markers_mutex);
848 return ret;
849}
850EXPORT_SYMBOL_GPL(marker_probe_unregister_private_data);
851
852/**
853 * marker_get_private_data - Get a marker's probe private data
854 * @name: marker name
855 * @probe: probe to match
856 * @num: get the nth matching probe's private data
857 *
858 * Returns the nth private data pointer (starting from 0) matching, or an
859 * ERR_PTR.
860 * Returns the private data pointer, or an ERR_PTR.
861 * The private data pointer should _only_ be dereferenced if the caller is the
862 * owner of the data, or its content could vanish. This is mostly used to
863 * confirm that a caller is the owner of a registered probe.
864 */
865void *marker_get_private_data(const char *name, marker_probe_func *probe,
866 int num)
867{
868 struct hlist_head *head;
869 struct hlist_node *node;
870 struct marker_entry *e;
871 size_t name_len = strlen(name) + 1;
872 u32 hash = jhash(name, name_len-1, 0);
873 int i;
874
875 head = &marker_table[hash & ((1 << MARKER_HASH_BITS)-1)];
876 hlist_for_each_entry(e, node, head, hlist) {
877 if (!strcmp(name, e->name)) {
878 if (!e->ptype) {
879 if (num == 0 && e->single.func == probe)
880 return e->single.probe_private;
881 } else {
882 struct marker_probe_closure *closure;
883 int match = 0;
884 closure = e->multi;
885 for (i = 0; closure[i].func; i++) {
886 if (closure[i].func != probe)
887 continue;
888 if (match++ == num)
889 return closure[i].probe_private;
890 }
891 }
892 break;
893 }
894 }
895 return ERR_PTR(-ENOENT);
896}
897EXPORT_SYMBOL_GPL(marker_get_private_data);
898
899#ifdef CONFIG_MODULES
900
901int marker_module_notify(struct notifier_block *self,
902 unsigned long val, void *data)
903{
904 struct module *mod = data;
905
906 switch (val) {
907 case MODULE_STATE_COMING:
908 marker_update_probe_range(mod->markers,
909 mod->markers + mod->num_markers);
910 break;
911 case MODULE_STATE_GOING:
912 marker_update_probe_range(mod->markers,
913 mod->markers + mod->num_markers);
914 break;
915 }
916 return 0;
917}
918
919struct notifier_block marker_module_nb = {
920 .notifier_call = marker_module_notify,
921 .priority = 0,
922};
923
924static int init_markers(void)
925{
926 return register_module_notifier(&marker_module_nb);
927}
928__initcall(init_markers);
929
930#endif /* CONFIG_MODULES */
diff --git a/kernel/module.c b/kernel/module.c
index 05ce49ced8f6..b6ee424245dd 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -2237,10 +2237,6 @@ static noinline struct module *load_module(void __user *umod,
2237 sizeof(*mod->ctors), &mod->num_ctors); 2237 sizeof(*mod->ctors), &mod->num_ctors);
2238#endif 2238#endif
2239 2239
2240#ifdef CONFIG_MARKERS
2241 mod->markers = section_objs(hdr, sechdrs, secstrings, "__markers",
2242 sizeof(*mod->markers), &mod->num_markers);
2243#endif
2244#ifdef CONFIG_TRACEPOINTS 2240#ifdef CONFIG_TRACEPOINTS
2245 mod->tracepoints = section_objs(hdr, sechdrs, secstrings, 2241 mod->tracepoints = section_objs(hdr, sechdrs, secstrings,
2246 "__tracepoints", 2242 "__tracepoints",
@@ -2958,20 +2954,6 @@ void module_layout(struct module *mod,
2958EXPORT_SYMBOL(module_layout); 2954EXPORT_SYMBOL(module_layout);
2959#endif 2955#endif
2960 2956
2961#ifdef CONFIG_MARKERS
2962void module_update_markers(void)
2963{
2964 struct module *mod;
2965
2966 mutex_lock(&module_mutex);
2967 list_for_each_entry(mod, &modules, list)
2968 if (!mod->taints)
2969 marker_update_probe_range(mod->markers,
2970 mod->markers + mod->num_markers);
2971 mutex_unlock(&module_mutex);
2972}
2973#endif
2974
2975#ifdef CONFIG_TRACEPOINTS 2957#ifdef CONFIG_TRACEPOINTS
2976void module_update_tracepoints(void) 2958void module_update_tracepoints(void)
2977{ 2959{
diff --git a/kernel/trace/trace_printk.c b/kernel/trace/trace_printk.c
index 687699d365ae..2547d8813cf0 100644
--- a/kernel/trace/trace_printk.c
+++ b/kernel/trace/trace_printk.c
@@ -11,7 +11,6 @@
11#include <linux/ftrace.h> 11#include <linux/ftrace.h>
12#include <linux/string.h> 12#include <linux/string.h>
13#include <linux/module.h> 13#include <linux/module.h>
14#include <linux/marker.h>
15#include <linux/mutex.h> 14#include <linux/mutex.h>
16#include <linux/ctype.h> 15#include <linux/ctype.h>
17#include <linux/list.h> 16#include <linux/list.h>
diff --git a/samples/Kconfig b/samples/Kconfig
index 428b065ba695..b92bde3c6a89 100644
--- a/samples/Kconfig
+++ b/samples/Kconfig
@@ -7,12 +7,6 @@ menuconfig SAMPLES
7 7
8if SAMPLES 8if SAMPLES
9 9
10config SAMPLE_MARKERS
11 tristate "Build markers examples -- loadable modules only"
12 depends on MARKERS && m
13 help
14 This build markers example modules.
15
16config SAMPLE_TRACEPOINTS 10config SAMPLE_TRACEPOINTS
17 tristate "Build tracepoints examples -- loadable modules only" 11 tristate "Build tracepoints examples -- loadable modules only"
18 depends on TRACEPOINTS && m 12 depends on TRACEPOINTS && m
diff --git a/samples/Makefile b/samples/Makefile
index 13e4b470b539..43343a03b1f4 100644
--- a/samples/Makefile
+++ b/samples/Makefile
@@ -1,3 +1,3 @@
1# Makefile for Linux samples code 1# Makefile for Linux samples code
2 2
3obj-$(CONFIG_SAMPLES) += markers/ kobject/ kprobes/ tracepoints/ trace_events/ 3obj-$(CONFIG_SAMPLES) += kobject/ kprobes/ tracepoints/ trace_events/
diff --git a/samples/markers/Makefile b/samples/markers/Makefile
deleted file mode 100644
index 6d7231265f0f..000000000000
--- a/samples/markers/Makefile
+++ /dev/null
@@ -1,4 +0,0 @@
1# builds the kprobes example kernel modules;
2# then to use one (as root): insmod <module_name.ko>
3
4obj-$(CONFIG_SAMPLE_MARKERS) += probe-example.o marker-example.o
diff --git a/samples/markers/marker-example.c b/samples/markers/marker-example.c
deleted file mode 100644
index e9cd9c0bc84f..000000000000
--- a/samples/markers/marker-example.c
+++ /dev/null
@@ -1,53 +0,0 @@
1/* marker-example.c
2 *
3 * Executes a marker when /proc/marker-example is opened.
4 *
5 * (C) Copyright 2007 Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
6 *
7 * This file is released under the GPLv2.
8 * See the file COPYING for more details.
9 */
10
11#include <linux/module.h>
12#include <linux/marker.h>
13#include <linux/sched.h>
14#include <linux/proc_fs.h>
15
16struct proc_dir_entry *pentry_example;
17
18static int my_open(struct inode *inode, struct file *file)
19{
20 int i;
21
22 trace_mark(subsystem_event, "integer %d string %s", 123,
23 "example string");
24 for (i = 0; i < 10; i++)
25 trace_mark(subsystem_eventb, MARK_NOARGS);
26 return -EPERM;
27}
28
29static struct file_operations mark_ops = {
30 .open = my_open,
31};
32
33static int __init example_init(void)
34{
35 printk(KERN_ALERT "example init\n");
36 pentry_example = proc_create("marker-example", 0444, NULL, &mark_ops);
37 if (!pentry_example)
38 return -EPERM;
39 return 0;
40}
41
42static void __exit example_exit(void)
43{
44 printk(KERN_ALERT "example exit\n");
45 remove_proc_entry("marker-example", NULL);
46}
47
48module_init(example_init)
49module_exit(example_exit)
50
51MODULE_LICENSE("GPL");
52MODULE_AUTHOR("Mathieu Desnoyers");
53MODULE_DESCRIPTION("Marker example");
diff --git a/samples/markers/probe-example.c b/samples/markers/probe-example.c
deleted file mode 100644
index 2dfb3b32937e..000000000000
--- a/samples/markers/probe-example.c
+++ /dev/null
@@ -1,92 +0,0 @@
1/* probe-example.c
2 *
3 * Connects two functions to marker call sites.
4 *
5 * (C) Copyright 2007 Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
6 *
7 * This file is released under the GPLv2.
8 * See the file COPYING for more details.
9 */
10
11#include <linux/sched.h>
12#include <linux/kernel.h>
13#include <linux/module.h>
14#include <linux/marker.h>
15#include <asm/atomic.h>
16
17struct probe_data {
18 const char *name;
19 const char *format;
20 marker_probe_func *probe_func;
21};
22
23void probe_subsystem_event(void *probe_data, void *call_data,
24 const char *format, va_list *args)
25{
26 /* Declare args */
27 unsigned int value;
28 const char *mystr;
29
30 /* Assign args */
31 value = va_arg(*args, typeof(value));
32 mystr = va_arg(*args, typeof(mystr));
33
34 /* Call printk */
35 printk(KERN_INFO "Value %u, string %s\n", value, mystr);
36
37 /* or count, check rights, serialize data in a buffer */
38}
39
40atomic_t eventb_count = ATOMIC_INIT(0);
41
42void probe_subsystem_eventb(void *probe_data, void *call_data,
43 const char *format, va_list *args)
44{
45 /* Increment counter */
46 atomic_inc(&eventb_count);
47}
48
49static struct probe_data probe_array[] =
50{
51 { .name = "subsystem_event",
52 .format = "integer %d string %s",
53 .probe_func = probe_subsystem_event },
54 { .name = "subsystem_eventb",
55 .format = MARK_NOARGS,
56 .probe_func = probe_subsystem_eventb },
57};
58
59static int __init probe_init(void)
60{
61 int result;
62 int i;
63
64 for (i = 0; i < ARRAY_SIZE(probe_array); i++) {
65 result = marker_probe_register(probe_array[i].name,
66 probe_array[i].format,
67 probe_array[i].probe_func, &probe_array[i]);
68 if (result)
69 printk(KERN_INFO "Unable to register probe %s\n",
70 probe_array[i].name);
71 }
72 return 0;
73}
74
75static void __exit probe_fini(void)
76{
77 int i;
78
79 for (i = 0; i < ARRAY_SIZE(probe_array); i++)
80 marker_probe_unregister(probe_array[i].name,
81 probe_array[i].probe_func, &probe_array[i]);
82 printk(KERN_INFO "Number of event b : %u\n",
83 atomic_read(&eventb_count));
84 marker_synchronize_unregister();
85}
86
87module_init(probe_init);
88module_exit(probe_fini);
89
90MODULE_LICENSE("GPL");
91MODULE_AUTHOR("Mathieu Desnoyers");
92MODULE_DESCRIPTION("SUBSYSTEM Probe");
diff --git a/scripts/Makefile.modpost b/scripts/Makefile.modpost
index f4053dc7b5d6..8f14c81abbc7 100644
--- a/scripts/Makefile.modpost
+++ b/scripts/Makefile.modpost
@@ -13,7 +13,6 @@
13# 2) modpost is then used to 13# 2) modpost is then used to
14# 3) create one <module>.mod.c file pr. module 14# 3) create one <module>.mod.c file pr. module
15# 4) create one Module.symvers file with CRC for all exported symbols 15# 4) create one Module.symvers file with CRC for all exported symbols
16# 4a) [CONFIG_MARKERS] create one Module.markers file listing defined markers
17# 5) compile all <module>.mod.c files 16# 5) compile all <module>.mod.c files
18# 6) final link of the module to a <module.ko> file 17# 6) final link of the module to a <module.ko> file
19 18
@@ -59,10 +58,6 @@ include scripts/Makefile.lib
59 58
60kernelsymfile := $(objtree)/Module.symvers 59kernelsymfile := $(objtree)/Module.symvers
61modulesymfile := $(firstword $(KBUILD_EXTMOD))/Module.symvers 60modulesymfile := $(firstword $(KBUILD_EXTMOD))/Module.symvers
62kernelmarkersfile := $(objtree)/Module.markers
63modulemarkersfile := $(firstword $(KBUILD_EXTMOD))/Module.markers
64
65markersfile = $(if $(KBUILD_EXTMOD),$(modulemarkersfile),$(kernelmarkersfile))
66 61
67# Step 1), find all modules listed in $(MODVERDIR)/ 62# Step 1), find all modules listed in $(MODVERDIR)/
68__modules := $(sort $(shell grep -h '\.ko' /dev/null $(wildcard $(MODVERDIR)/*.mod))) 63__modules := $(sort $(shell grep -h '\.ko' /dev/null $(wildcard $(MODVERDIR)/*.mod)))
@@ -85,8 +80,6 @@ modpost = scripts/mod/modpost \
85 $(if $(KBUILD_EXTRA_SYMBOLS), $(patsubst %, -e %,$(KBUILD_EXTRA_SYMBOLS))) \ 80 $(if $(KBUILD_EXTRA_SYMBOLS), $(patsubst %, -e %,$(KBUILD_EXTRA_SYMBOLS))) \
86 $(if $(KBUILD_EXTMOD),-o $(modulesymfile)) \ 81 $(if $(KBUILD_EXTMOD),-o $(modulesymfile)) \
87 $(if $(CONFIG_DEBUG_SECTION_MISMATCH),,-S) \ 82 $(if $(CONFIG_DEBUG_SECTION_MISMATCH),,-S) \
88 $(if $(CONFIG_MARKERS),-K $(kernelmarkersfile)) \
89 $(if $(CONFIG_MARKERS),-M $(markersfile)) \
90 $(if $(KBUILD_EXTMOD)$(KBUILD_MODPOST_WARN),-w) \ 83 $(if $(KBUILD_EXTMOD)$(KBUILD_MODPOST_WARN),-w) \
91 $(if $(cross_build),-c) 84 $(if $(cross_build),-c)
92 85
@@ -101,17 +94,12 @@ quiet_cmd_kernel-mod = MODPOST $@
101 cmd_kernel-mod = $(modpost) $@ 94 cmd_kernel-mod = $(modpost) $@
102 95
103vmlinux.o: FORCE 96vmlinux.o: FORCE
104 @rm -fr $(kernelmarkersfile)
105 $(call cmd,kernel-mod) 97 $(call cmd,kernel-mod)
106 98
107# Declare generated files as targets for modpost 99# Declare generated files as targets for modpost
108$(symverfile): __modpost ; 100$(symverfile): __modpost ;
109$(modules:.ko=.mod.c): __modpost ; 101$(modules:.ko=.mod.c): __modpost ;
110 102
111ifdef CONFIG_MARKERS
112$(markersfile): __modpost ;
113endif
114
115 103
116# Step 5), compile all *.mod.c files 104# Step 5), compile all *.mod.c files
117 105
generated by cgit v1.2.2 (git 2.25.0) at 2026-03-06 11:55:25 -0500