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authorChristoph Hellwig <hch@lst.de>2009-09-17 19:35:28 +0200
committerIngo Molnar <mingo@elte.hu>2009-09-18 21:22:08 +0200
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>
-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 @@
- Using the Linux Kernel Markers
-
- Mathieu Desnoyers
-
-
-This document introduces Linux Kernel Markers and their use. It provides
-examples of how to insert markers in the kernel and connect probe functions to
-them and provides some examples of probe functions.
-
-
-* Purpose of markers
-
-A marker placed in code provides a hook to call a function (probe) that you can
-provide at runtime. A marker can be "on" (a probe is connected to it) or "off"
-(no probe is attached). When a marker is "off" it has no effect, except for
-adding a tiny time penalty (checking a condition for a branch) and space
-penalty (adding a few bytes for the function call at the end of the
-instrumented function and adds a data structure in a separate section). When a
-marker is "on", the function you provide is called each time the marker is
-executed, in the execution context of the caller. When the function provided
-ends its execution, it returns to the caller (continuing from the marker site).
-
-You can put markers at important locations in the code. Markers are
-lightweight hooks that can pass an arbitrary number of parameters,
-described in a printk-like format string, to the attached probe function.
-
-They can be used for tracing and performance accounting.
-
-
-* Usage
-
-In order to use the macro trace_mark, you should include linux/marker.h.
-
-#include <linux/marker.h>
-
-And,
-
-trace_mark(subsystem_event, "myint %d mystring %s", someint, somestring);
-Where :
-- subsystem_event is an identifier unique to your event
- - subsystem is the name of your subsystem.
- - event is the name of the event to mark.
-- "myint %d mystring %s" is the formatted string for the serializer. "myint" and
- "mystring" are repectively the field names associated with the first and
- second parameter.
-- someint is an integer.
-- somestring is a char pointer.
-
-Connecting a function (probe) to a marker is done by providing a probe (function
-to call) for the specific marker through marker_probe_register() and can be
-activated by calling marker_arm(). Marker deactivation can be done by calling
-marker_disarm() as many times as marker_arm() has been called. Removing a probe
-is done through marker_probe_unregister(); it will disarm the probe.
-
-marker_synchronize_unregister() must be called between probe unregistration and
-the first occurrence of
-- the end of module exit function,
- to make sure there is no caller left using the probe;
-- the free of any resource used by the probes,
- to make sure the probes wont be accessing invalid data.
-This, and the fact that preemption is disabled around the probe call, make sure
-that probe removal and module unload are safe. See the "Probe example" section
-below for a sample probe module.
-
-The marker mechanism supports inserting multiple instances of the same marker.
-Markers can be put in inline functions, inlined static functions, and
-unrolled loops as well as regular functions.
-
-The naming scheme "subsystem_event" is suggested here as a convention intended
-to limit collisions. Marker names are global to the kernel: they are considered
-as being the same whether they are in the core kernel image or in modules.
-Conflicting format strings for markers with the same name will cause the markers
-to be detected to have a different format string not to be armed and will output
-a printk warning which identifies the inconsistency:
-
-"Format mismatch for probe probe_name (format), marker (format)"
-
-Another way to use markers is to simply define the marker without generating any
-function call to actually call into the marker. This is useful in combination
-with tracepoint probes in a scheme like this :
-
-void probe_tracepoint_name(unsigned int arg1, struct task_struct *tsk);
-
-DEFINE_MARKER_TP(marker_eventname, tracepoint_name, probe_tracepoint_name,
- "arg1 %u pid %d");
-
-notrace void probe_tracepoint_name(unsigned int arg1, struct task_struct *tsk)
-{
- struct marker *marker = &GET_MARKER(kernel_irq_entry);
- /* write data to trace buffers ... */
-}
-
-* Probe / marker example
-
-See the example provided in samples/markers/src
-
-Compile them with your kernel.
-
-Run, as root :
-modprobe marker-example (insmod order is not important)
-modprobe probe-example
-cat /proc/marker-example (returns an expected error)
-rmmod marker-example probe-example
-dmesg
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 @@
#include <linux/poll.h>
#include <linux/ptrace.h>
#include <linux/seq_file.h>
-#include <linux/marker.h>
#include <asm/io.h>
#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 @@
#include <linux/pid_namespace.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
-#include <linux/marker.h>
#include <asm/io.h>
#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 @@
#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/preempt.h>
-#include <linux/marker.h>
#include <linux/msi.h>
#include <asm/signal.h>
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 @@
-#ifndef _LINUX_MARKER_H
-#define _LINUX_MARKER_H
-
-/*
- * Code markup for dynamic and static tracing.
- *
- * See Documentation/marker.txt.
- *
- * (C) Copyright 2006 Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
- *
- * This file is released under the GPLv2.
- * See the file COPYING for more details.
- */
-
-#include <stdarg.h>
-#include <linux/types.h>
-
-struct module;
-struct marker;
-
-/**
- * marker_probe_func - Type of a marker probe function
- * @probe_private: probe private data
- * @call_private: call site private data
- * @fmt: format string
- * @args: variable argument list pointer. Use a pointer to overcome C's
- * inability to pass this around as a pointer in a portable manner in
- * the callee otherwise.
- *
- * Type of marker probe functions. They receive the mdata and need to parse the
- * format string to recover the variable argument list.
- */
-typedef void marker_probe_func(void *probe_private, void *call_private,
- const char *fmt, va_list *args);
-
-struct marker_probe_closure {
- marker_probe_func *func; /* Callback */
- void *probe_private; /* Private probe data */
-};
-
-struct marker {
- const char *name; /* Marker name */
- const char *format; /* Marker format string, describing the
- * variable argument list.
- */
- char state; /* Marker state. */
- char ptype; /* probe type : 0 : single, 1 : multi */
- /* Probe wrapper */
- void (*call)(const struct marker *mdata, void *call_private, ...);
- struct marker_probe_closure single;
- struct marker_probe_closure *multi;
- const char *tp_name; /* Optional tracepoint name */
- void *tp_cb; /* Optional tracepoint callback */
-} __attribute__((aligned(8)));
-
-#ifdef CONFIG_MARKERS
-
-#define _DEFINE_MARKER(name, tp_name_str, tp_cb, format) \
- static const char __mstrtab_##name[] \
- __attribute__((section("__markers_strings"))) \
- = #name "\0" format; \
- static struct marker __mark_##name \
- __attribute__((section("__markers"), aligned(8))) = \
- { __mstrtab_##name, &__mstrtab_##name[sizeof(#name)], \
- 0, 0, marker_probe_cb, { __mark_empty_function, NULL},\
- NULL, tp_name_str, tp_cb }
-
-#define DEFINE_MARKER(name, format) \
- _DEFINE_MARKER(name, NULL, NULL, format)
-
-#define DEFINE_MARKER_TP(name, tp_name, tp_cb, format) \
- _DEFINE_MARKER(name, #tp_name, tp_cb, format)
-
-/*
- * Note : the empty asm volatile with read constraint is used here instead of a
- * "used" attribute to fix a gcc 4.1.x bug.
- * Make sure the alignment of the structure in the __markers section will
- * not add unwanted padding between the beginning of the section and the
- * structure. Force alignment to the same alignment as the section start.
- *
- * The "generic" argument controls which marker enabling mechanism must be used.
- * If generic is true, a variable read is used.
- * If generic is false, immediate values are used.
- */
-#define __trace_mark(generic, name, call_private, format, args...) \
- do { \
- DEFINE_MARKER(name, format); \
- __mark_check_format(format, ## args); \
- if (unlikely(__mark_##name.state)) { \
- (*__mark_##name.call) \
- (&__mark_##name, call_private, ## args);\
- } \
- } while (0)
-
-#define __trace_mark_tp(name, call_private, tp_name, tp_cb, format, args...) \
- do { \
- void __check_tp_type(void) \
- { \
- register_trace_##tp_name(tp_cb); \
- } \
- DEFINE_MARKER_TP(name, tp_name, tp_cb, format); \
- __mark_check_format(format, ## args); \
- (*__mark_##name.call)(&__mark_##name, call_private, \
- ## args); \
- } while (0)
-
-extern void marker_update_probe_range(struct marker *begin,
- struct marker *end);
-
-#define GET_MARKER(name) (__mark_##name)
-
-#else /* !CONFIG_MARKERS */
-#define DEFINE_MARKER(name, tp_name, tp_cb, format)
-#define __trace_mark(generic, name, call_private, format, args...) \
- __mark_check_format(format, ## args)
-#define __trace_mark_tp(name, call_private, tp_name, tp_cb, format, args...) \
- do { \
- void __check_tp_type(void) \
- { \
- register_trace_##tp_name(tp_cb); \
- } \
- __mark_check_format(format, ## args); \
- } while (0)
-static inline void marker_update_probe_range(struct marker *begin,
- struct marker *end)
-{ }
-#define GET_MARKER(name)
-#endif /* CONFIG_MARKERS */
-
-/**
- * trace_mark - Marker using code patching
- * @name: marker name, not quoted.
- * @format: format string
- * @args...: variable argument list
- *
- * Places a marker using optimized code patching technique (imv_read())
- * to be enabled when immediate values are present.
- */
-#define trace_mark(name, format, args...) \
- __trace_mark(0, name, NULL, format, ## args)
-
-/**
- * _trace_mark - Marker using variable read
- * @name: marker name, not quoted.
- * @format: format string
- * @args...: variable argument list
- *
- * Places a marker using a standard memory read (_imv_read()) to be
- * enabled. Should be used for markers in code paths where instruction
- * modification based enabling is not welcome. (__init and __exit functions,
- * lockdep, some traps, printk).
- */
-#define _trace_mark(name, format, args...) \
- __trace_mark(1, name, NULL, format, ## args)
-
-/**
- * trace_mark_tp - Marker in a tracepoint callback
- * @name: marker name, not quoted.
- * @tp_name: tracepoint name, not quoted.
- * @tp_cb: tracepoint callback. Should have an associated global symbol so it
- * is not optimized away by the compiler (should not be static).
- * @format: format string
- * @args...: variable argument list
- *
- * Places a marker in a tracepoint callback.
- */
-#define trace_mark_tp(name, tp_name, tp_cb, format, args...) \
- __trace_mark_tp(name, NULL, tp_name, tp_cb, format, ## args)
-
-/**
- * MARK_NOARGS - Format string for a marker with no argument.
- */
-#define MARK_NOARGS " "
-
-/* To be used for string format validity checking with gcc */
-static inline void __printf(1, 2) ___mark_check_format(const char *fmt, ...)
-{
-}
-
-#define __mark_check_format(format, args...) \
- do { \
- if (0) \
- ___mark_check_format(format, ## args); \
- } while (0)
-
-extern marker_probe_func __mark_empty_function;
-
-extern void marker_probe_cb(const struct marker *mdata,
- void *call_private, ...);
-
-/*
- * Connect a probe to a marker.
- * private data pointer must be a valid allocated memory address, or NULL.
- */
-extern int marker_probe_register(const char *name, const char *format,
- marker_probe_func *probe, void *probe_private);
-
-/*
- * Returns the private data given to marker_probe_register.
- */
-extern int marker_probe_unregister(const char *name,
- marker_probe_func *probe, void *probe_private);
-/*
- * Unregister a marker by providing the registered private data.
- */
-extern int marker_probe_unregister_private_data(marker_probe_func *probe,
- void *probe_private);
-
-extern void *marker_get_private_data(const char *name, marker_probe_func *probe,
- int num);
-
-/*
- * marker_synchronize_unregister must be called between the last marker probe
- * unregistration and the first one of
- * - the end of module exit function
- * - the free of any resource used by the probes
- * to ensure the code and data are valid for any possibly running probes.
- */
-#define marker_synchronize_unregister() synchronize_sched()
-
-#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 @@
#include <linux/stringify.h>
#include <linux/kobject.h>
#include <linux/moduleparam.h>
-#include <linux/marker.h>
#include <linux/tracepoint.h>
#include <asm/local.h>
@@ -327,10 +326,6 @@ struct module
/* The command line arguments (may be mangled). People like
keeping pointers to this stuff */
char *args;
-#ifdef CONFIG_MARKERS
- struct marker *markers;
- unsigned int num_markers;
-#endif
#ifdef CONFIG_TRACEPOINTS
struct tracepoint *tracepoints;
unsigned int num_tracepoints;
@@ -535,8 +530,6 @@ int unregister_module_notifier(struct notifier_block * nb);
extern void print_modules(void);
-extern void module_update_markers(void);
-
extern void module_update_tracepoints(void);
extern int module_get_iter_tracepoints(struct tracepoint_iter *iter);
@@ -651,10 +644,6 @@ static inline void print_modules(void)
{
}
-static inline void module_update_markers(void)
-{
-}
-
static inline void module_update_tracepoints(void)
{
}
diff --git a/init/Kconfig b/init/Kconfig
index 8e8b76d8a272..4cc0fa13d5eb 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -1054,13 +1054,6 @@ config PROFILING
config TRACEPOINTS
bool
-config MARKERS
- bool "Activate markers"
- select TRACEPOINTS
- help
- Place an empty function call at each marker site. Can be
- dynamically changed for a probe function.
-
source "arch/Kconfig"
config 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-$(CONFIG_RELAY) += relay.o
obj-$(CONFIG_SYSCTL) += utsname_sysctl.o
obj-$(CONFIG_TASK_DELAY_ACCT) += delayacct.o
obj-$(CONFIG_TASKSTATS) += taskstats.o tsacct.o
-obj-$(CONFIG_MARKERS) += marker.o
obj-$(CONFIG_TRACEPOINTS) += tracepoint.o
obj-$(CONFIG_LATENCYTOP) += latencytop.o
obj-$(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 @@
-/*
- * Copyright (C) 2007 Mathieu Desnoyers
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
- */
-#include <linux/module.h>
-#include <linux/mutex.h>
-#include <linux/types.h>
-#include <linux/jhash.h>
-#include <linux/list.h>
-#include <linux/rcupdate.h>
-#include <linux/marker.h>
-#include <linux/err.h>
-#include <linux/slab.h>
-
-extern struct marker __start___markers[];
-extern struct marker __stop___markers[];
-
-/* Set to 1 to enable marker debug output */
-static const int marker_debug;
-
-/*
- * markers_mutex nests inside module_mutex. Markers mutex protects the builtin
- * and module markers and the hash table.
- */
-static DEFINE_MUTEX(markers_mutex);
-
-/*
- * Marker hash table, containing the active markers.
- * Protected by module_mutex.
- */
-#define MARKER_HASH_BITS 6
-#define MARKER_TABLE_SIZE (1 << MARKER_HASH_BITS)
-static struct hlist_head marker_table[MARKER_TABLE_SIZE];
-
-/*
- * Note about RCU :
- * It is used to make sure every handler has finished using its private data
- * between two consecutive operation (add or remove) on a given marker. It is
- * also used to delay the free of multiple probes array until a quiescent state
- * is reached.
- * marker entries modifications are protected by the markers_mutex.
- */
-struct marker_entry {
- struct hlist_node hlist;
- char *format;
- /* Probe wrapper */
- void (*call)(const struct marker *mdata, void *call_private, ...);
- struct marker_probe_closure single;
- struct marker_probe_closure *multi;
- int refcount; /* Number of times armed. 0 if disarmed. */
- struct rcu_head rcu;
- void *oldptr;
- int rcu_pending;
- unsigned char ptype:1;
- unsigned char format_allocated:1;
- char name[0]; /* Contains name'\0'format'\0' */
-};
-
-/**
- * __mark_empty_function - Empty probe callback
- * @probe_private: probe private data
- * @call_private: call site private data
- * @fmt: format string
- * @...: variable argument list
- *
- * Empty callback provided as a probe to the markers. By providing this to a
- * disabled marker, we make sure the execution flow is always valid even
- * though the function pointer change and the marker enabling are two distinct
- * operations that modifies the execution flow of preemptible code.
- */
-notrace void __mark_empty_function(void *probe_private, void *call_private,
- const char *fmt, va_list *args)
-{
-}
-EXPORT_SYMBOL_GPL(__mark_empty_function);
-
-/*
- * marker_probe_cb Callback that prepares the variable argument list for probes.
- * @mdata: pointer of type struct marker
- * @call_private: caller site private data
- * @...: Variable argument list.
- *
- * Since we do not use "typical" pointer based RCU in the 1 argument case, we
- * need to put a full smp_rmb() in this branch. This is why we do not use
- * rcu_dereference() for the pointer read.
- */
-notrace void marker_probe_cb(const struct marker *mdata,
- void *call_private, ...)
-{
- va_list args;
- char ptype;
-
- /*
- * rcu_read_lock_sched does two things : disabling preemption to make
- * sure the teardown of the callbacks can be done correctly when they
- * are in modules and they insure RCU read coherency.
- */
- rcu_read_lock_sched_notrace();
- ptype = mdata->ptype;
- if (likely(!ptype)) {
- marker_probe_func *func;
- /* Must read the ptype before ptr. They are not data dependant,
- * so we put an explicit smp_rmb() here. */
- smp_rmb();
- func = mdata->single.func;
- /* Must read the ptr before private data. They are not data
- * dependant, so we put an explicit smp_rmb() here. */
- smp_rmb();
- va_start(args, call_private);
- func(mdata->single.probe_private, call_private, mdata->format,
- &args);
- va_end(args);
- } else {
- struct marker_probe_closure *multi;
- int i;
- /*
- * Read mdata->ptype before mdata->multi.
- */
- smp_rmb();
- multi = mdata->multi;
- /*
- * multi points to an array, therefore accessing the array
- * depends on reading multi. However, even in this case,
- * we must insure that the pointer is read _before_ the array
- * data. Same as rcu_dereference, but we need a full smp_rmb()
- * in the fast path, so put the explicit barrier here.
- */
- smp_read_barrier_depends();
- for (i = 0; multi[i].func; i++) {
- va_start(args, call_private);
- multi[i].func(multi[i].probe_private, call_private,
- mdata->format, &args);
- va_end(args);
- }
- }
- rcu_read_unlock_sched_notrace();
-}
-EXPORT_SYMBOL_GPL(marker_probe_cb);
-
-/*
- * marker_probe_cb Callback that does not prepare the variable argument list.
- * @mdata: pointer of type struct marker
- * @call_private: caller site private data
- * @...: Variable argument list.
- *
- * Should be connected to markers "MARK_NOARGS".
- */
-static notrace void marker_probe_cb_noarg(const struct marker *mdata,
- void *call_private, ...)
-{
- va_list args; /* not initialized */
- char ptype;
-
- rcu_read_lock_sched_notrace();
- ptype = mdata->ptype;
- if (likely(!ptype)) {
- marker_probe_func *func;
- /* Must read the ptype before ptr. They are not data dependant,
- * so we put an explicit smp_rmb() here. */
- smp_rmb();
- func = mdata->single.func;
- /* Must read the ptr before private data. They are not data
- * dependant, so we put an explicit smp_rmb() here. */
- smp_rmb();
- func(mdata->single.probe_private, call_private, mdata->format,
- &args);
- } else {
- struct marker_probe_closure *multi;
- int i;
- /*
- * Read mdata->ptype before mdata->multi.
- */
- smp_rmb();
- multi = mdata->multi;
- /*
- * multi points to an array, therefore accessing the array
- * depends on reading multi. However, even in this case,
- * we must insure that the pointer is read _before_ the array
- * data. Same as rcu_dereference, but we need a full smp_rmb()
- * in the fast path, so put the explicit barrier here.
- */
- smp_read_barrier_depends();
- for (i = 0; multi[i].func; i++)
- multi[i].func(multi[i].probe_private, call_private,
- mdata->format, &args);
- }
- rcu_read_unlock_sched_notrace();
-}
-
-static void free_old_closure(struct rcu_head *head)
-{
- struct marker_entry *entry = container_of(head,
- struct marker_entry, rcu);
- kfree(entry->oldptr);
- /* Make sure we free the data before setting the pending flag to 0 */
- smp_wmb();
- entry->rcu_pending = 0;
-}
-
-static void debug_print_probes(struct marker_entry *entry)
-{
- int i;
-
- if (!marker_debug)
- return;
-
- if (!entry->ptype) {
- printk(KERN_DEBUG "Single probe : %p %p\n",
- entry->single.func,
- entry->single.probe_private);
- } else {
- for (i = 0; entry->multi[i].func; i++)
- printk(KERN_DEBUG "Multi probe %d : %p %p\n", i,
- entry->multi[i].func,
- entry->multi[i].probe_private);
- }
-}
-
-static struct marker_probe_closure *
-marker_entry_add_probe(struct marker_entry *entry,
- marker_probe_func *probe, void *probe_private)
-{
- int nr_probes = 0;
- struct marker_probe_closure *old, *new;
-
- WARN_ON(!probe);
-
- debug_print_probes(entry);
- old = entry->multi;
- if (!entry->ptype) {
- if (entry->single.func == probe &&
- entry->single.probe_private == probe_private)
- return ERR_PTR(-EBUSY);
- if (entry->single.func == __mark_empty_function) {
- /* 0 -> 1 probes */
- entry->single.func = probe;
- entry->single.probe_private = probe_private;
- entry->refcount = 1;
- entry->ptype = 0;
- debug_print_probes(entry);
- return NULL;
- } else {
- /* 1 -> 2 probes */
- nr_probes = 1;
- old = NULL;
- }
- } else {
- /* (N -> N+1), (N != 0, 1) probes */
- for (nr_probes = 0; old[nr_probes].func; nr_probes++)
- if (old[nr_probes].func == probe
- && old[nr_probes].probe_private
- == probe_private)
- return ERR_PTR(-EBUSY);
- }
- /* + 2 : one for new probe, one for NULL func */
- new = kzalloc((nr_probes + 2) * sizeof(struct marker_probe_closure),
- GFP_KERNEL);
- if (new == NULL)
- return ERR_PTR(-ENOMEM);
- if (!old)
- new[0] = entry->single;
- else
- memcpy(new, old,
- nr_probes * sizeof(struct marker_probe_closure));
- new[nr_probes].func = probe;
- new[nr_probes].probe_private = probe_private;
- entry->refcount = nr_probes + 1;
- entry->multi = new;
- entry->ptype = 1;
- debug_print_probes(entry);
- return old;
-}
-
-static struct marker_probe_closure *
-marker_entry_remove_probe(struct marker_entry *entry,
- marker_probe_func *probe, void *probe_private)
-{
- int nr_probes = 0, nr_del = 0, i;
- struct marker_probe_closure *old, *new;
-
- old = entry->multi;
-
- debug_print_probes(entry);
- if (!entry->ptype) {
- /* 0 -> N is an error */
- WARN_ON(entry->single.func == __mark_empty_function);
- /* 1 -> 0 probes */
- WARN_ON(probe && entry->single.func != probe);
- WARN_ON(entry->single.probe_private != probe_private);
- entry->single.func = __mark_empty_function;
- entry->refcount = 0;
- entry->ptype = 0;
- debug_print_probes(entry);
- return NULL;
- } else {
- /* (N -> M), (N > 1, M >= 0) probes */
- for (nr_probes = 0; old[nr_probes].func; nr_probes++) {
- if ((!probe || old[nr_probes].func == probe)
- && old[nr_probes].probe_private
- == probe_private)
- nr_del++;
- }
- }
-
- if (nr_probes - nr_del == 0) {
- /* N -> 0, (N > 1) */
- entry->single.func = __mark_empty_function;
- entry->refcount = 0;
- entry->ptype = 0;
- } else if (nr_probes - nr_del == 1) {
- /* N -> 1, (N > 1) */
- for (i = 0; old[i].func; i++)
- if ((probe && old[i].func != probe) ||
- old[i].probe_private != probe_private)
- entry->single = old[i];
- entry->refcount = 1;
- entry->ptype = 0;
- } else {
- int j = 0;
- /* N -> M, (N > 1, M > 1) */
- /* + 1 for NULL */
- new = kzalloc((nr_probes - nr_del + 1)
- * sizeof(struct marker_probe_closure), GFP_KERNEL);
- if (new == NULL)
- return ERR_PTR(-ENOMEM);
- for (i = 0; old[i].func; i++)
- if ((probe && old[i].func != probe) ||
- old[i].probe_private != probe_private)
- new[j++] = old[i];
- entry->refcount = nr_probes - nr_del;
- entry->ptype = 1;
- entry->multi = new;
- }
- debug_print_probes(entry);
- return old;
-}
-
-/*
- * Get marker if the marker is present in the marker hash table.
- * Must be called with markers_mutex held.
- * Returns NULL if not present.
- */
-static struct marker_entry *get_marker(const char *name)
-{
- struct hlist_head *head;
- struct hlist_node *node;
- struct marker_entry *e;
- u32 hash = jhash(name, strlen(name), 0);
-
- head = &marker_table[hash & ((1 << MARKER_HASH_BITS)-1)];
- hlist_for_each_entry(e, node, head, hlist) {
- if (!strcmp(name, e->name))
- return e;
- }
- return NULL;
-}
-
-/*
- * Add the marker to the marker hash table. Must be called with markers_mutex
- * held.
- */
-static struct marker_entry *add_marker(const char *name, const char *format)
-{
- struct hlist_head *head;
- struct hlist_node *node;
- struct marker_entry *e;
- size_t name_len = strlen(name) + 1;
- size_t format_len = 0;
- u32 hash = jhash(name, name_len-1, 0);
-
- if (format)
- format_len = strlen(format) + 1;
- head = &marker_table[hash & ((1 << MARKER_HASH_BITS)-1)];
- hlist_for_each_entry(e, node, head, hlist) {
- if (!strcmp(name, e->name)) {
- printk(KERN_NOTICE
- "Marker %s busy\n", name);
- return ERR_PTR(-EBUSY); /* Already there */
- }
- }
- /*
- * Using kmalloc here to allocate a variable length element. Could
- * cause some memory fragmentation if overused.
- */
- e = kmalloc(sizeof(struct marker_entry) + name_len + format_len,
- GFP_KERNEL);
- if (!e)
- return ERR_PTR(-ENOMEM);
- memcpy(&e->name[0], name, name_len);
- if (format) {
- e->format = &e->name[name_len];
- memcpy(e->format, format, format_len);
- if (strcmp(e->format, MARK_NOARGS) == 0)
- e->call = marker_probe_cb_noarg;
- else
- e->call = marker_probe_cb;
- trace_mark(core_marker_format, "name %s format %s",
- e->name, e->format);
- } else {
- e->format = NULL;
- e->call = marker_probe_cb;
- }
- e->single.func = __mark_empty_function;
- e->single.probe_private = NULL;
- e->multi = NULL;
- e->ptype = 0;
- e->format_allocated = 0;
- e->refcount = 0;
- e->rcu_pending = 0;
- hlist_add_head(&e->hlist, head);
- return e;
-}
-
-/*
- * Remove the marker from the marker hash table. Must be called with mutex_lock
- * held.
- */
-static int remove_marker(const char *name)
-{
- struct hlist_head *head;
- struct hlist_node *node;
- struct marker_entry *e;
- int found = 0;
- size_t len = strlen(name) + 1;
- u32 hash = jhash(name, len-1, 0);
-
- head = &marker_table[hash & ((1 << MARKER_HASH_BITS)-1)];
- hlist_for_each_entry(e, node, head, hlist) {
- if (!strcmp(name, e->name)) {
- found = 1;
- break;
- }
- }
- if (!found)
- return -ENOENT;
- if (e->single.func != __mark_empty_function)
- return -EBUSY;
- hlist_del(&e->hlist);
- if (e->format_allocated)
- kfree(e->format);
- /* Make sure the call_rcu has been executed */
- if (e->rcu_pending)
- rcu_barrier_sched();
- kfree(e);
- return 0;
-}
-
-/*
- * Set the mark_entry format to the format found in the element.
- */
-static int marker_set_format(struct marker_entry *entry, const char *format)
-{
- entry->format = kstrdup(format, GFP_KERNEL);
- if (!entry->format)
- return -ENOMEM;
- entry->format_allocated = 1;
-
- trace_mark(core_marker_format, "name %s format %s",
- entry->name, entry->format);
- return 0;
-}
-
-/*
- * Sets the probe callback corresponding to one marker.
- */
-static int set_marker(struct marker_entry *entry, struct marker *elem,
- int active)
-{
- int ret = 0;
- WARN_ON(strcmp(entry->name, elem->name) != 0);
-
- if (entry->format) {
- if (strcmp(entry->format, elem->format) != 0) {
- printk(KERN_NOTICE
- "Format mismatch for probe %s "
- "(%s), marker (%s)\n",
- entry->name,
- entry->format,
- elem->format);
- return -EPERM;
- }
- } else {
- ret = marker_set_format(entry, elem->format);
- if (ret)
- return ret;
- }
-
- /*
- * probe_cb setup (statically known) is done here. It is
- * asynchronous with the rest of execution, therefore we only
- * pass from a "safe" callback (with argument) to an "unsafe"
- * callback (does not set arguments).