acc4988bcf
Wrap __mark_check_format() into an if(0) to make sure that parameters such as trace_mark(mm_page_alloc, "order %u pfn %lu", order, page?page_to_pfn(page):0); (where page_to_pfn() has side-effects) won't generate code because of the __mark_check_format(). Thanks to Jan Kiszka for reporting this. Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> Cc: Jan Kiszka <jan.kiszka@siemens.com> Cc: "Frank Ch. Eigler" <fche@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
146 lines
4.3 KiB
C
146 lines
4.3 KiB
C
#ifndef _LINUX_MARKER_H
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#define _LINUX_MARKER_H
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/*
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* Code markup for dynamic and static tracing.
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*
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* See Documentation/marker.txt.
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*
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* (C) Copyright 2006 Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
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*
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* This file is released under the GPLv2.
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* See the file COPYING for more details.
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*/
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#include <linux/types.h>
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struct module;
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struct marker;
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/**
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* marker_probe_func - Type of a marker probe function
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* @probe_private: probe private data
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* @call_private: call site private data
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* @fmt: format string
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* @args: variable argument list pointer. Use a pointer to overcome C's
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* inability to pass this around as a pointer in a portable manner in
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* the callee otherwise.
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*
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* Type of marker probe functions. They receive the mdata and need to parse the
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* format string to recover the variable argument list.
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*/
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typedef void marker_probe_func(void *probe_private, void *call_private,
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const char *fmt, va_list *args);
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struct marker_probe_closure {
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marker_probe_func *func; /* Callback */
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void *probe_private; /* Private probe data */
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};
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struct marker {
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const char *name; /* Marker name */
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const char *format; /* Marker format string, describing the
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* variable argument list.
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*/
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char state; /* Marker state. */
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char ptype; /* probe type : 0 : single, 1 : multi */
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void (*call)(const struct marker *mdata, /* Probe wrapper */
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void *call_private, const char *fmt, ...);
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struct marker_probe_closure single;
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struct marker_probe_closure *multi;
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} __attribute__((aligned(8)));
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#ifdef CONFIG_MARKERS
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/*
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* Note : the empty asm volatile with read constraint is used here instead of a
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* "used" attribute to fix a gcc 4.1.x bug.
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* Make sure the alignment of the structure in the __markers section will
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* not add unwanted padding between the beginning of the section and the
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* structure. Force alignment to the same alignment as the section start.
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*/
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#define __trace_mark(name, call_private, format, args...) \
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do { \
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static const char __mstrtab_##name[] \
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__attribute__((section("__markers_strings"))) \
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= #name "\0" format; \
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static struct marker __mark_##name \
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__attribute__((section("__markers"), aligned(8))) = \
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{ __mstrtab_##name, &__mstrtab_##name[sizeof(#name)], \
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0, 0, marker_probe_cb, \
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{ __mark_empty_function, NULL}, NULL }; \
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__mark_check_format(format, ## args); \
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if (unlikely(__mark_##name.state)) { \
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(*__mark_##name.call) \
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(&__mark_##name, call_private, \
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format, ## args); \
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} \
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} while (0)
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extern void marker_update_probe_range(struct marker *begin,
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struct marker *end);
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#else /* !CONFIG_MARKERS */
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#define __trace_mark(name, call_private, format, args...) \
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__mark_check_format(format, ## args)
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static inline void marker_update_probe_range(struct marker *begin,
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struct marker *end)
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{ }
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#endif /* CONFIG_MARKERS */
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/**
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* trace_mark - Marker
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* @name: marker name, not quoted.
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* @format: format string
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* @args...: variable argument list
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*
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* Places a marker.
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*/
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#define trace_mark(name, format, args...) \
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__trace_mark(name, NULL, format, ## args)
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/**
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* MARK_NOARGS - Format string for a marker with no argument.
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*/
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#define MARK_NOARGS " "
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/* To be used for string format validity checking with gcc */
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static inline void __printf(1, 2) ___mark_check_format(const char *fmt, ...)
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{
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}
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#define __mark_check_format(format, args...) \
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do { \
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if (0) \
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___mark_check_format(format, ## args); \
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} while (0)
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extern marker_probe_func __mark_empty_function;
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extern void marker_probe_cb(const struct marker *mdata,
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void *call_private, const char *fmt, ...);
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extern void marker_probe_cb_noarg(const struct marker *mdata,
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void *call_private, const char *fmt, ...);
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/*
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* Connect a probe to a marker.
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* private data pointer must be a valid allocated memory address, or NULL.
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*/
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extern int marker_probe_register(const char *name, const char *format,
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marker_probe_func *probe, void *probe_private);
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/*
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* Returns the private data given to marker_probe_register.
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*/
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extern int marker_probe_unregister(const char *name,
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marker_probe_func *probe, void *probe_private);
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/*
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* Unregister a marker by providing the registered private data.
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*/
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extern int marker_probe_unregister_private_data(marker_probe_func *probe,
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void *probe_private);
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extern void *marker_get_private_data(const char *name, marker_probe_func *probe,
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int num);
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#endif
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