diff options
| -rw-r--r-- | Documentation/markers.txt | 104 | ||||
| -rw-r--r-- | arch/powerpc/platforms/cell/spufs/file.c | 1 | ||||
| -rw-r--r-- | arch/powerpc/platforms/cell/spufs/sched.c | 1 | ||||
| -rw-r--r-- | include/linux/kvm_host.h | 1 | ||||
| -rw-r--r-- | include/linux/marker.h | 221 | ||||
| -rw-r--r-- | include/linux/module.h | 11 | ||||
| -rw-r--r-- | init/Kconfig | 7 | ||||
| -rw-r--r-- | kernel/Makefile | 1 | ||||
| -rw-r--r-- | kernel/marker.c | 930 | ||||
| -rw-r--r-- | kernel/module.c | 18 | ||||
| -rw-r--r-- | kernel/trace/trace_printk.c | 1 | ||||
| -rw-r--r-- | samples/Kconfig | 6 | ||||
| -rw-r--r-- | samples/Makefile | 2 | ||||
| -rw-r--r-- | samples/markers/Makefile | 4 | ||||
| -rw-r--r-- | samples/markers/marker-example.c | 53 | ||||
| -rw-r--r-- | samples/markers/probe-example.c | 92 | ||||
| -rw-r--r-- | scripts/Makefile.modpost | 12 |
17 files changed, 1 insertions, 1464 deletions
diff --git a/Documentation/markers.txt b/Documentation/markers.txt deleted file mode 100644 index d2b3d0e91b2..00000000000 --- 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 ab8aef9bb8e..8f079b865ad 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 bb5b77c66d0..4678078fede 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 4af56036a6b..b7bbb5ddd7a 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 b85e74ca782..00000000000 --- 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 f8f92d015ef..1c755b2f937 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 8e8b76d8a27..4cc0fa13d5e 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 3d9c7e27e3f..7c9b0a58550 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 ea54f264786..00000000000 --- 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). - */ - elem->call = entry->call; - /* - * Sanity check : - * We only update the single probe private data when the ptr is - * set to a _non_ single probe! (0 -> 1 and N -> 1, N != 1) - */ - WARN_ON(elem->single.func != __mark_empty_function - && elem->single.probe_private != entry->single.probe_private - && !elem->ptype); - elem->single.probe_private = entry->single.probe_private; - /* - * Make sure the private data is valid when we update the - * single probe ptr. - */ - smp_wmb(); - elem->single.func = entry->single.func; - /* - * We also make sure that the new probe callbacks array is consistent - * before setting a pointer to it. - */ - rcu_assign_pointer(elem->m |