lttng wrappers

Implement wrappers for compatibility with older kernel versions and
kernels with had the libringbuffer (old) patchset applied.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/staging/lttng/wrapper/ftrace.h

+#ifndef _LTT_WRAPPER_FTRACE_H
+#define _LTT_WRAPPER_FTRACE_H
+
+/*
+ * Copyright (C) 2011 Mathieu Desnoyers (mathieu.desnoyers@efficios.com)
+ *
+ * wrapper around vmalloc_sync_all. Using KALLSYMS to get its address when
+ * available, else we need to have a kernel that exports this function to GPL
+ * modules.
+ *
+ * Dual LGPL v2.1/GPL v2 license.
+ */
+
+#include <linux/ftrace.h>
+
+#ifdef CONFIG_KALLSYMS
+
+#include <linux/kallsyms.h>
+#include "kallsyms.h"
+
+static inline
+int wrapper_register_ftrace_function_probe(char *glob,
+		struct ftrace_probe_ops *ops, void *data)
+{
+	int (*register_ftrace_function_probe_sym)(char *glob,
+			struct ftrace_probe_ops *ops, void *data);
+
+	register_ftrace_function_probe_sym = (void *) kallsyms_lookup_funcptr("register_ftrace_function_probe");
+	if (register_ftrace_function_probe_sym) {
+		return register_ftrace_function_probe_sym(glob, ops, data);
+	} else {
+		printk(KERN_WARNING "LTTng: register_ftrace_function_probe symbol lookup failed.\n");
+		return -EINVAL;
+	}
+}
+
+static inline
+void wrapper_unregister_ftrace_function_probe(char *glob,
+		struct ftrace_probe_ops *ops, void *data)
+{
+	void (*unregister_ftrace_function_probe_sym)(char *glob,
+			struct ftrace_probe_ops *ops, void *data);
+
+	unregister_ftrace_function_probe_sym = (void *) kallsyms_lookup_funcptr("unregister_ftrace_function_probe");
+	if (unregister_ftrace_function_probe_sym) {
+		unregister_ftrace_function_probe_sym(glob, ops, data);
+	} else {
+		printk(KERN_WARNING "LTTng: unregister_ftrace_function_probe symbol lookup failed.\n");
+		WARN_ON(1);
+	}
+}
+
+#else
+
+static inline
+int wrapper_register_ftrace_function_probe(char *glob,
+		struct ftrace_probe_ops *ops, void *data)
+{
+	return register_ftrace_function_probe(glob, ops, data);
+}
+
+static inline
+void wrapper_unregister_ftrace_function_probe(char *glob,
+		struct ftrace_probe_ops *ops, void *data)
+{
+	return unregister_ftrace_function_probe(glob, ops, data);
+}
+#endif
+
+#endif /* _LTT_WRAPPER_FTRACE_H */

drivers/staging/lttng/wrapper/inline_memcpy.h

+/*
+ * wrapper/inline_memcpy.h
+ *
+ * Copyright (C) 2010-2011 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ *
+ * Dual LGPL v2.1/GPL v2 license.
+ */
+
+#if !defined(__HAVE_ARCH_INLINE_MEMCPY) && !defined(inline_memcpy)
+#define inline_memcpy memcpy
+#endif

drivers/staging/lttng/wrapper/kallsyms.h

+#ifndef _LTT_WRAPPER_KALLSYMS_H
+#define _LTT_WRAPPER_KALLSYMS_H
+
+/*
+ * Copyright (C) 2011 Avik Sil (avik.sil@linaro.org)
+ *
+ * wrapper around kallsyms_lookup_name. Implements arch-dependent code for
+ * arches where the address of the start of the function body is different
+ * from the pointer which can be used to call the function, e.g. ARM THUMB2.
+ *
+ * Dual LGPL v2.1/GPL v2 license.
+ */
+
+static inline
+unsigned long kallsyms_lookup_funcptr(const char *name)
+{
+	unsigned long addr;
+
+	addr = kallsyms_lookup_name(name);
+#ifdef CONFIG_ARM
+#ifdef CONFIG_THUMB2_KERNEL
+	if (addr)
+		addr |= 1; /* set bit 0 in address for thumb mode */
+#endif
+#endif
+	return addr;
+}
+#endif /* _LTT_WRAPPER_KALLSYMS_H */

drivers/staging/lttng/wrapper/perf.h

+#ifndef _LTT_WRAPPER_PERF_H
+#define _LTT_WRAPPER_PERF_H
+
+/*
+ * Copyright (C) 2011 Mathieu Desnoyers (mathieu.desnoyers@efficios.com)
+ *
+ * Dual LGPL v2.1/GPL v2 license.
+ */
+
+#include <linux/perf_event.h>
+
+#if defined(CONFIG_PERF_EVENTS) && (LINUX_VERSION_CODE >= KERNEL_VERSION(3,0,99))
+static inline struct perf_event *
+wrapper_perf_event_create_kernel_counter(struct perf_event_attr *attr,
+				int cpu,
+				struct task_struct *task,
+				perf_overflow_handler_t callback)
+{
+	return perf_event_create_kernel_counter(attr, cpu, task, callback, NULL);
+}
+#else
+static inline struct perf_event *
+wrapper_perf_event_create_kernel_counter(struct perf_event_attr *attr,
+				int cpu,
+				struct task_struct *task,
+				perf_overflow_handler_t callback)
+{
+	return perf_event_create_kernel_counter(attr, cpu, task, callback);
+}
+#endif
+
+#endif /* _LTT_WRAPPER_PERF_H */

drivers/staging/lttng/wrapper/poll.h

+#ifndef _LTTNG_WRAPPER_POLL_H
+#define _LTTNG_WRAPPER_POLL_H
+
+/*
+ * Copyright (C) 2011 Mathieu Desnoyers (mathieu.desnoyers@efficios.com)
+ *
+ * Dual LGPL v2.1/GPL v2 license.
+ */
+
+#include <linux/poll.h>
+
+#define poll_wait_set_exclusive(poll_table)
+
+#endif /* _LTTNG_WRAPPER_POLL_H */

drivers/staging/lttng/wrapper/ringbuffer/api.h

+#include "../../lib/ringbuffer/api.h"

drivers/staging/lttng/wrapper/ringbuffer/backend.h

+#include "../../lib/ringbuffer/backend.h"

drivers/staging/lttng/wrapper/ringbuffer/backend_internal.h

+#include "../../wrapper/inline_memcpy.h"
+#include "../../lib/ringbuffer/backend_internal.h"

drivers/staging/lttng/wrapper/ringbuffer/backend_types.h

+#include "../../lib/ringbuffer/backend_types.h"

drivers/staging/lttng/wrapper/ringbuffer/config.h

+#include "../../lib/ringbuffer/config.h"

drivers/staging/lttng/wrapper/ringbuffer/frontend.h

+#include "../../lib/ringbuffer/frontend.h"

drivers/staging/lttng/wrapper/ringbuffer/frontend_api.h

+#include "../../lib/ringbuffer/frontend_api.h"

drivers/staging/lttng/wrapper/ringbuffer/frontend_internal.h

+#include "../../lib/ringbuffer/frontend_internal.h"

drivers/staging/lttng/wrapper/ringbuffer/frontend_types.h

+#include "../../lib/ringbuffer/frontend_types.h"

drivers/staging/lttng/wrapper/ringbuffer/iterator.h

+#include "../../lib/ringbuffer/iterator.h"

drivers/staging/lttng/wrapper/ringbuffer/nohz.h

+#include "../../lib/ringbuffer/nohz.h"

drivers/staging/lttng/wrapper/ringbuffer/vatomic.h

+#include "../../lib/ringbuffer/vatomic.h"

drivers/staging/lttng/wrapper/ringbuffer/vfs.h

+#include "../../lib/ringbuffer/vfs.h"

drivers/staging/lttng/wrapper/spinlock.h

+#ifndef _LTT_WRAPPER_SPINLOCK_H
+#define _LTT_WRAPPER_SPINLOCK_H
+
+/*
+ * Copyright (C) 2011 Mathieu Desnoyers (mathieu.desnoyers@efficios.com)
+ *
+ * Dual LGPL v2.1/GPL v2 license.
+ */
+
+#include <linux/version.h>
+
+#if (LINUX_VERSION_CODE < KERNEL_VERSION(2,6,33))
+
+#include <linux/string.h>
+
+#define raw_spin_lock_init(lock)					\
+	do {								\
+		raw_spinlock_t __lock = __RAW_SPIN_LOCK_UNLOCKED;	\
+		memcpy(lock, &__lock, sizeof(lock));			\
+	} while (0)
+
+#define raw_spin_is_locked(lock)	__raw_spin_is_locked(lock)
+
+
+#endif
+#endif /* _LTT_WRAPPER_SPINLOCK_H */

drivers/staging/lttng/wrapper/splice.c

+/*
+ * Copyright (C) 2011 Mathieu Desnoyers (mathieu.desnoyers@efficios.com)
+ *
+ * wrapper around vmalloc_sync_all. Using KALLSYMS to get its address when
+ * available, else we need to have a kernel that exports this function to GPL
+ * modules.
+ *
+ * Dual LGPL v2.1/GPL v2 license.
+ */
+
+#ifdef CONFIG_KALLSYMS
+
+#include <linux/kallsyms.h>
+#include <linux/fs.h>
+#include <linux/splice.h>
+#include "kallsyms.h"
+
+static
+ssize_t (*splice_to_pipe_sym)(struct pipe_inode_info *pipe,
+			      struct splice_pipe_desc *spd);
+
+ssize_t wrapper_splice_to_pipe(struct pipe_inode_info *pipe,
+			       struct splice_pipe_desc *spd)
+{
+	if (!splice_to_pipe_sym)
+		splice_to_pipe_sym = (void *) kallsyms_lookup_funcptr("splice_to_pipe"); 
+	if (splice_to_pipe_sym) {
+		return splice_to_pipe_sym(pipe, spd);
+	} else {
+		printk(KERN_WARNING "LTTng: splice_to_pipe symbol lookup failed.\n");
+		return -ENOSYS;
+	}
+}
+
+#else
+
+#include <linux/fs.h>
+#include <linux/splice.h>
+
+ssize_t wrapper_splice_to_pipe(struct pipe_inode_info *pipe,
+			       struct splice_pipe_desc *spd)
+{
+	return splice_to_pipe(pipe, spd);
+}
+
+#endif

drivers/staging/lttng/wrapper/splice.h

+#ifndef _LTT_WRAPPER_SPLICE_H
+#define _LTT_WRAPPER_SPLICE_H
+
+/*
+ * Copyright (C) 2011 Mathieu Desnoyers (mathieu.desnoyers@efficios.com)
+ *
+ * wrapper around vmalloc_sync_all. Using KALLSYMS to get its address when
+ * available, else we need to have a kernel that exports this function to GPL
+ * modules.
+ *
+ * Dual LGPL v2.1/GPL v2 license.
+ */
+
+#include <linux/splice.h>
+
+ssize_t wrapper_splice_to_pipe(struct pipe_inode_info *pipe,
+			       struct splice_pipe_desc *spd);
+
+#ifndef PIPE_DEF_BUFFERS
+#define PIPE_DEF_BUFFERS 16
+#endif
+
+#endif /* _LTT_WRAPPER_SPLICE_H */

drivers/staging/lttng/wrapper/trace-clock.h

+/*
+ * Copyright (C) 2011 Mathieu Desnoyers (mathieu.desnoyers@efficios.com)
+ *
+ * Contains LTTng trace clock mapping to LTTng trace clock or mainline monotonic
+ * clock. This wrapper depends on CONFIG_HIGH_RES_TIMERS=y.
+ *
+ * Dual LGPL v2.1/GPL v2 license.
+ */
+
+#ifndef _LTT_TRACE_CLOCK_H
+#define _LTT_TRACE_CLOCK_H
+
+#ifdef CONFIG_HAVE_TRACE_CLOCK
+#include <linux/trace-clock.h>
+#else /* CONFIG_HAVE_TRACE_CLOCK */
+
+#include <linux/hardirq.h>
+#include <linux/ktime.h>
+#include <linux/time.h>
+#include <linux/hrtimer.h>
+
+static inline u64 trace_clock_monotonic_wrapper(void)
+{
+	ktime_t ktime;
+
+	/*
+	 * Refuse to trace from NMIs with this wrapper, because an NMI could
+	 * nest over the xtime write seqlock and deadlock.
+	 */
+	if (in_nmi())
+		return (u64) -EIO;
+
+	ktime = ktime_get();
+	return (u64) ktime.tv64;
+}
+
+static inline u32 trace_clock_read32(void)
+{
+	return (u32) trace_clock_monotonic_wrapper();
+}
+
+static inline u64 trace_clock_read64(void)
+{
+	return (u64) trace_clock_monotonic_wrapper();
+}
+
+static inline u64 trace_clock_frequency(void)
+{
+	return (u64)NSEC_PER_SEC;
+}
+
+static inline u32 trace_clock_freq_scale(void)
+{
+	return 1;
+}
+
+static inline int get_trace_clock(void)
+{
+	printk(KERN_WARNING "LTTng: Using mainline kernel monotonic clock.\n");
+	printk(KERN_WARNING "  * NMIs will not be traced,\n");
+	printk(KERN_WARNING "  * expect significant performance degradation compared to the\n");
+	printk(KERN_WARNING "    LTTng trace clocks.\n");
+	printk(KERN_WARNING "Integration of the LTTng 0.x trace clocks into LTTng 2.0 is planned\n");
+	printk(KERN_WARNING "in a near future.\n");
+
+	return 0;
+}
+
+static inline void put_trace_clock(void)
+{
+}
+
+#endif /* CONFIG_HAVE_TRACE_CLOCK */
+
+#endif /* _LTT_TRACE_CLOCK_H */

drivers/staging/lttng/wrapper/uuid.h

+#ifndef _LTT_WRAPPER_UUID_H
+#define _LTT_WRAPPER_UUID_H
+
+/*
+ * Copyright (C) 2011 Mathieu Desnoyers (mathieu.desnoyers@efficios.com)
+ *
+ * Dual LGPL v2.1/GPL v2 license.
+ */
+
+#include <linux/version.h>
+
+#if (LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,35))
+#include <linux/uuid.h>
+#else
+
+#include <linux/random.h>
+
+typedef struct {
+	__u8 b[16];
+} uuid_le;
+
+static inline
+void uuid_le_gen(uuid_le *u)
+{
+	generate_random_uuid(u->b);
+}
+
+#endif
+#endif /* _LTT_WRAPPER_UUID_H */

drivers/staging/lttng/wrapper/vmalloc.h

+#ifndef _LTT_WRAPPER_VMALLOC_H
+#define _LTT_WRAPPER_VMALLOC_H
+
+/*
+ * Copyright (C) 2011 Mathieu Desnoyers (mathieu.desnoyers@efficios.com)
+ *
+ * wrapper around vmalloc_sync_all. Using KALLSYMS to get its address when
+ * available, else we need to have a kernel that exports this function to GPL
+ * modules.
+ *
+ * Dual LGPL v2.1/GPL v2 license.
+ */
+
+#ifdef CONFIG_KALLSYMS
+
+#include <linux/kallsyms.h>
+#include "kallsyms.h"
+
+static inline
+void wrapper_vmalloc_sync_all(void)
+{
+	void (*vmalloc_sync_all_sym)(void);
+
+	vmalloc_sync_all_sym = (void *) kallsyms_lookup_funcptr("vmalloc_sync_all");
+	if (vmalloc_sync_all_sym) {
+		vmalloc_sync_all_sym();
+	} else {
+#ifdef CONFIG_X86
+		/*
+		 * Only x86 needs vmalloc_sync_all to make sure LTTng does not
+		 * trigger recursive page faults.
+		 */
+		printk(KERN_WARNING "LTTng: vmalloc_sync_all symbol lookup failed.\n");
+		printk(KERN_WARNING "Page fault handler and NMI tracing might trigger faults.\n");
+#endif
+	}
+}
+#else
+
+#include <linux/vmalloc.h>
+
+static inline
+void wrapper_vmalloc_sync_all(void)
+{
+	return vmalloc_sync_all();
+}
+#endif
+
+#endif /* _LTT_WRAPPER_VMALLOC_H */