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Merge branches 'tracing/branch-tracer', 'tracing/ftrace', 'tracing/function-return-tracer', 'tracing/tracepoints' and 'tracing/urgent' into tracing/core

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This commit is contained in:
Ingo Molnar 2008-11-17 09:36:22 +01:00
commit 3f8e402f34
39 changed files with 889 additions and 477 deletions
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14
Documentation/markers.txt
View File

@ -70,6 +70,20 @@ 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

86
Documentation/tracepoints.txt
View File

@ -3,28 +3,30 @@
Mathieu Desnoyers
This document introduces Linux Kernel Tracepoints and their use. It provides
examples of how to insert tracepoints in the kernel and connect probe functions
to them and provides some examples of probe functions.
This document introduces Linux Kernel Tracepoints and their use. It
provides examples of how to insert tracepoints in the kernel and
connect probe functions to them and provides some examples of probe
functions.
* Purpose of tracepoints
A tracepoint placed in code provides a hook to call a function (probe) that you
can provide at runtime. A tracepoint can be "on" (a probe is connected to it) or
"off" (no probe is attached). When a tracepoint 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
tracepoint is "on", the function you provide is called each time the tracepoint
is executed, in the execution context of the caller. When the function provided
ends its execution, it returns to the caller (continuing from the tracepoint
site).
A tracepoint placed in code provides a hook to call a function (probe)
that you can provide at runtime. A tracepoint can be "on" (a probe is
connected to it) or "off" (no probe is attached). When a tracepoint 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 tracepoint
is "on", the function you provide is called each time the tracepoint
is executed, in the execution context of the caller. When the function
provided ends its execution, it returns to the caller (continuing from
the tracepoint site).
You can put tracepoints at important locations in the code. They are
lightweight hooks that can pass an arbitrary number of parameters,
which prototypes are described in a tracepoint declaration placed in a header
file.
which prototypes are described in a tracepoint declaration placed in a
header file.
They can be used for tracing and performance accounting.
@ -42,7 +44,7 @@ In include/trace/subsys.h :
#include <linux/tracepoint.h>
DEFINE_TRACE(subsys_eventname,
DECLARE_TRACE(subsys_eventname,
TPPTOTO(int firstarg, struct task_struct *p),
TPARGS(firstarg, p));
@ -50,6 +52,8 @@ In subsys/file.c (where the tracing statement must be added) :
#include <trace/subsys.h>
DEFINE_TRACE(subsys_eventname);
void somefct(void)
{
...
@ -61,31 +65,41 @@ Where :
- subsys_eventname is an identifier unique to your event
- subsys is the name of your subsystem.
- eventname is the name of the event to trace.
- TPPTOTO(int firstarg, struct task_struct *p) is the prototype of the function
called by this tracepoint.
- TPARGS(firstarg, p) are the parameters names, same as found in the prototype.
Connecting a function (probe) to a tracepoint is done by providing a probe
(function to call) for the specific tracepoint through
- TPPTOTO(int firstarg, struct task_struct *p) is the prototype of the
function called by this tracepoint.
- TPARGS(firstarg, p) are the parameters names, same as found in the
prototype.
Connecting a function (probe) to a tracepoint is done by providing a
probe (function to call) for the specific tracepoint through
register_trace_subsys_eventname(). Removing a probe is done through
unregister_trace_subsys_eventname(); it will remove the probe sure there is no
caller left using the probe when it returns. Probe removal is preempt-safe
because preemption is disabled around the probe call. See the "Probe example"
section below for a sample probe module.
unregister_trace_subsys_eventname(); it will remove the probe.
The tracepoint mechanism supports inserting multiple instances of the same
tracepoint, but a single definition must be made of a given tracepoint name over
all the kernel to make sure no type conflict will occur. Name mangling of the
tracepoints is done using the prototypes to make sure typing is correct.
Verification of probe type correctness is done at the registration site by the
compiler. Tracepoints can be put in inline functions, inlined static functions,
and unrolled loops as well as regular functions.
tracepoint_synchronize_unregister() must be called before the end of
the module exit function to make sure there is no caller left using
the probe. 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 naming scheme "subsys_event" is suggested here as a convention intended
to limit collisions. Tracepoint names are global to the kernel: they are
considered as being the same whether they are in the core kernel image or in
modules.
The tracepoint mechanism supports inserting multiple instances of the
same tracepoint, but a single definition must be made of a given
tracepoint name over all the kernel to make sure no type conflict will
occur. Name mangling of the tracepoints is done using the prototypes
to make sure typing is correct. Verification of probe type correctness
is done at the registration site by the compiler. Tracepoints can be
put in inline functions, inlined static functions, and unrolled loops
as well as regular functions.
The naming scheme "subsys_event" is suggested here as a convention
intended to limit collisions. Tracepoint names are global to the
kernel: they are considered as being the same whether they are in the
core kernel image or in modules.
If the tracepoint has to be used in kernel modules, an
EXPORT_TRACEPOINT_SYMBOL_GPL() or EXPORT_TRACEPOINT_SYMBOL() can be
used to export the defined tracepoints.
* Probe / tracepoint example

8
arch/x86/include/asm/ftrace.h
View File

@ -17,6 +17,14 @@ static inline unsigned long ftrace_call_adjust(unsigned long addr)
*/
return addr - 1;
}
#ifdef CONFIG_DYNAMIC_FTRACE
struct dyn_arch_ftrace {
/* No extra data needed for x86 */
};
#endif /* CONFIG_DYNAMIC_FTRACE */
#endif /* __ASSEMBLY__ */
#endif /* CONFIG_FUNCTION_TRACER */

18
arch/x86/kernel/entry_32.S
View File

@ -1190,7 +1190,7 @@ ENTRY(mcount)
jnz trace
#ifdef CONFIG_FUNCTION_RET_TRACER
cmpl $ftrace_stub, ftrace_function_return
jnz trace_return
jnz ftrace_return_caller
#endif
.globl ftrace_stub
ftrace_stub:
@ -1211,9 +1211,15 @@ trace:
popl %ecx
popl %eax
jmp ftrace_stub
END(mcount)
#endif /* CONFIG_DYNAMIC_FTRACE */
#endif /* CONFIG_FUNCTION_TRACER */
#ifdef CONFIG_FUNCTION_RET_TRACER
trace_return:
ENTRY(ftrace_return_caller)
cmpl $0, function_trace_stop
jne ftrace_stub
pushl %eax
pushl %ecx
pushl %edx
@ -1223,7 +1229,8 @@ trace_return:
popl %edx
popl %ecx
popl %eax
jmp ftrace_stub
ret
END(ftrace_return_caller)
.globl return_to_handler
return_to_handler:
@ -1237,10 +1244,7 @@ return_to_handler:
popl %ecx
popl %eax
ret
#endif /* CONFIG_FUNCTION_RET_TRACER */
END(mcount)
#endif /* CONFIG_DYNAMIC_FTRACE */
#endif /* CONFIG_FUNCTION_TRACER */
#endif
.section .rodata,"a"
#include "syscall_table_32.S"

286
arch/x86/kernel/ftrace.c
View File

@ -24,133 +24,6 @@
#include <asm/nmi.h>
#ifdef CONFIG_FUNCTION_RET_TRACER
/*
* These functions are picked from those used on
* this page for dynamic ftrace. They have been
* simplified to ignore all traces in NMI context.
*/
static atomic_t in_nmi;
void ftrace_nmi_enter(void)
{
atomic_inc(&in_nmi);
}
void ftrace_nmi_exit(void)
{
atomic_dec(&in_nmi);
}
/* Add a function return address to the trace stack on thread info.*/
static int push_return_trace(unsigned long ret, unsigned long long time,
unsigned long func)
{
int index;
struct thread_info *ti = current_thread_info();
/* The return trace stack is full */
if (ti->curr_ret_stack == FTRACE_RET_STACK_SIZE - 1)
return -EBUSY;
index = ++ti->curr_ret_stack;
ti->ret_stack[index].ret = ret;
ti->ret_stack[index].func = func;
ti->ret_stack[index].calltime = time;
return 0;
}
/* Retrieve a function return address to the trace stack on thread info.*/
static void pop_return_trace(unsigned long *ret, unsigned long long *time,
unsigned long *func)
{
int index;
struct thread_info *ti = current_thread_info();
index = ti->curr_ret_stack;
*ret = ti->ret_stack[index].ret;
*func = ti->ret_stack[index].func;
*time = ti->ret_stack[index].calltime;
ti->curr_ret_stack--;
}
/*
* Send the trace to the ring-buffer.
* @return the original return address.
*/
unsigned long ftrace_return_to_handler(void)
{
struct ftrace_retfunc trace;
pop_return_trace(&trace.ret, &trace.calltime, &trace.func);
trace.rettime = cpu_clock(raw_smp_processor_id());
ftrace_function_return(&trace);
return trace.ret;
}
/*
* Hook the return address and push it in the stack of return addrs
* in current thread info.
*/
void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr)
{
unsigned long old;
unsigned long long calltime;
int faulted;
unsigned long return_hooker = (unsigned long)
&return_to_handler;
/* Nmi's are currently unsupported */
if (atomic_read(&in_nmi))
return;
/*
* Protect against fault, even if it shouldn't
* happen. This tool is too much intrusive to
* ignore such a protection.
*/
asm volatile(
"1: movl (%[parent_old]), %[old]\n"
"2: movl %[return_hooker], (%[parent_replaced])\n"
" movl $0, %[faulted]\n"
".section .fixup, \"ax\"\n"
"3: movl $1, %[faulted]\n"
".previous\n"
".section __ex_table, \"a\"\n"
" .long 1b, 3b\n"
" .long 2b, 3b\n"
".previous\n"
: [parent_replaced] "=r" (parent), [old] "=r" (old),
[faulted] "=r" (faulted)
: [parent_old] "0" (parent), [return_hooker] "r" (return_hooker)
: "memory"
);
if (WARN_ON(faulted)) {
unregister_ftrace_return();
return;
}
if (WARN_ON(!__kernel_text_address(old))) {
unregister_ftrace_return();
*parent = old;
return;
}
calltime = cpu_clock(raw_smp_processor_id());
if (push_return_trace(old, calltime, self_addr) == -EBUSY)
*parent = old;
}
#endif
#ifdef CONFIG_DYNAMIC_FTRACE
union ftrace_code_union {
@ -166,7 +39,7 @@ static int ftrace_calc_offset(long ip, long addr)
return (int)(addr - ip);
}
unsigned char *ftrace_call_replace(unsigned long ip, unsigned long addr)
static unsigned char *ftrace_call_replace(unsigned long ip, unsigned long addr)
{
static union ftrace_code_union calc;
@ -311,12 +184,12 @@ do_ftrace_mod_code(unsigned long ip, void *new_code)
static unsigned char ftrace_nop[MCOUNT_INSN_SIZE];
unsigned char *ftrace_nop_replace(void)
static unsigned char *ftrace_nop_replace(void)
{
return ftrace_nop;
}
int
static int
ftrace_modify_code(unsigned long ip, unsigned char *old_code,
unsigned char *new_code)
{
@ -349,6 +222,29 @@ ftrace_modify_code(unsigned long ip, unsigned char *old_code,
return 0;
}
int ftrace_make_nop(struct module *mod,
struct dyn_ftrace *rec, unsigned long addr)
{
unsigned char *new, *old;
unsigned long ip = rec->ip;
old = ftrace_call_replace(ip, addr);
new = ftrace_nop_replace();
return ftrace_modify_code(rec->ip, old, new);
}
int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr)
{
unsigned char *new, *old;
unsigned long ip = rec->ip;
old = ftrace_nop_replace();
new = ftrace_call_replace(ip, addr);
return ftrace_modify_code(rec->ip, old, new);
}
int ftrace_update_ftrace_func(ftrace_func_t func)
{
unsigned long ip = (unsigned long)(&ftrace_call);
@ -426,3 +322,133 @@ int __init ftrace_dyn_arch_init(void *data)
return 0;
}
#endif
#ifdef CONFIG_FUNCTION_RET_TRACER
#ifndef CONFIG_DYNAMIC_FTRACE
/*
* These functions are picked from those used on
* this page for dynamic ftrace. They have been
* simplified to ignore all traces in NMI context.
*/
static atomic_t in_nmi;
void ftrace_nmi_enter(void)
{
atomic_inc(&in_nmi);
}
void ftrace_nmi_exit(void)
{
atomic_dec(&in_nmi);
}
#endif /* !CONFIG_DYNAMIC_FTRACE */
/* Add a function return address to the trace stack on thread info.*/
static int push_return_trace(unsigned long ret, unsigned long long time,
unsigned long func)
{
int index;
struct thread_info *ti = current_thread_info();
/* The return trace stack is full */
if (ti->curr_ret_stack == FTRACE_RET_STACK_SIZE - 1)
return -EBUSY;
index = ++ti->curr_ret_stack;
barrier();
ti->ret_stack[index].ret = ret;
ti->ret_stack[index].func = func;
ti->ret_stack[index].calltime = time;
return 0;
}
/* Retrieve a function return address to the trace stack on thread info.*/
static void pop_return_trace(unsigned long *ret, unsigned long long *time,
unsigned long *func)
{
int index;
struct thread_info *ti = current_thread_info();
index = ti->curr_ret_stack;
*ret = ti->ret_stack[index].ret;
*func = ti->ret_stack[index].func;
*time = ti->ret_stack[index].calltime;
ti->curr_ret_stack--;
}
/*
* Send the trace to the ring-buffer.
* @return the original return address.
*/
unsigned long ftrace_return_to_handler(void)
{
struct ftrace_retfunc trace;
pop_return_trace(&trace.ret, &trace.calltime, &trace.func);
trace.rettime = cpu_clock(raw_smp_processor_id());
ftrace_function_return(&trace);
return trace.ret;
}
/*
* Hook the return address and push it in the stack of return addrs
* in current thread info.
*/
void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr)
{
unsigned long old;
unsigned long long calltime;
int faulted;
unsigned long return_hooker = (unsigned long)
&return_to_handler;
/* Nmi's are currently unsupported */
if (atomic_read(&in_nmi))
return;
/*
* Protect against fault, even if it shouldn't
* happen. This tool is too much intrusive to
* ignore such a protection.
*/
asm volatile(
"1: movl (%[parent_old]), %[old]\n"
"2: movl %[return_hooker], (%[parent_replaced])\n"
" movl $0, %[faulted]\n"
".section .fixup, \"ax\"\n"
"3: movl $1, %[faulted]\n"
".previous\n"
".section __ex_table, \"a\"\n"
" .long 1b, 3b\n"
" .long 2b, 3b\n"
".previous\n"
: [parent_replaced] "=r" (parent), [old] "=r" (old),
[faulted] "=r" (faulted)
: [parent_old] "0" (parent), [return_hooker] "r" (return_hooker)
: "memory"
);
if (WARN_ON(faulted)) {
unregister_ftrace_return();
return;
}
if (WARN_ON(!__kernel_text_address(old))) {
unregister_ftrace_return();
*parent = old;
return;
}
calltime = cpu_clock(raw_smp_processor_id());
if (push_return_trace(old, calltime, self_addr) == -EBUSY)
*parent = old;
}
#endif /* CONFIG_FUNCTION_RET_TRACER */

1
include/asm-generic/vmlinux.lds.h
View File

@ -71,6 +71,7 @@
VMLINUX_SYMBOL(__start___markers) = .; \
*(__markers) \
VMLINUX_SYMBOL(__stop___markers) = .; \
. = ALIGN(32); \
VMLINUX_SYMBOL(__start___tracepoints) = .; \
*(__tracepoints) \
VMLINUX_SYMBOL(__stop___tracepoints) = .; \

71
include/linux/ftrace.h
View File

@ -25,6 +25,17 @@ struct ftrace_ops {
extern int function_trace_stop;
/*
* Type of the current tracing.
*/
enum ftrace_tracing_type_t {
FTRACE_TYPE_ENTER = 0, /* Hook the call of the function */
FTRACE_TYPE_RETURN, /* Hook the return of the function */
};
/* Current tracing type, default is FTRACE_TYPE_ENTER */
extern enum ftrace_tracing_type_t ftrace_tracing_type;
/**
* ftrace_stop - stop function tracer.
*
@ -74,6 +85,9 @@ static inline void ftrace_start(void) { }
#endif /* CONFIG_FUNCTION_TRACER */
#ifdef CONFIG_DYNAMIC_FTRACE
/* asm/ftrace.h must be defined for archs supporting dynamic ftrace */
#include <asm/ftrace.h>
enum {
FTRACE_FL_FREE = (1 << 0),
FTRACE_FL_FAILED = (1 << 1),
@ -88,6 +102,7 @@ struct dyn_ftrace {
struct list_head list;
unsigned long ip; /* address of mcount call-site */
unsigned long flags;
struct dyn_arch_ftrace arch;
};
int ftrace_force_update(void);
@ -95,22 +110,20 @@ void ftrace_set_filter(unsigned char *buf, int len, int reset);
/* defined in arch */
extern int ftrace_ip_converted(unsigned long ip);
extern unsigned char *ftrace_nop_replace(void);
extern unsigned char *ftrace_call_replace(unsigned long ip, unsigned long addr);
extern int ftrace_dyn_arch_init(void *data);
extern int ftrace_update_ftrace_func(ftrace_func_t func);
extern void ftrace_caller(void);
extern void ftrace_call(void);
extern void mcount_call(void);
/* May be defined in arch */
extern int ftrace_arch_read_dyn_info(char *buf, int size);
#ifdef CONFIG_FUNCTION_RET_TRACER
extern void ftrace_return_caller(void);
#endif
/**
* ftrace_modify_code - modify code segment
* @ip: the address of the code segment
* @old_code: the contents of what is expected to be there
* @new_code: the code to patch in
* ftrace_make_nop - convert code into top
* @mod: module structure if called by module load initialization
* @rec: the mcount call site record
* @addr: the address that the call site should be calling
*
* This is a very sensitive operation and great care needs
* to be taken by the arch. The operation should carefully
@ -118,6 +131,8 @@ extern int ftrace_arch_read_dyn_info(char *buf, int size);
* what we expect it to be, and then on success of the compare,
* it should write to the location.
*
* The code segment at @rec->ip should be a caller to @addr
*
* Return must be:
* 0 on success
* -EFAULT on error reading the location
@ -125,8 +140,34 @@ extern int ftrace_arch_read_dyn_info(char *buf, int size);
* -EPERM on error writing to the location
* Any other value will be considered a failure.
*/
extern int ftrace_modify_code(unsigned long ip, unsigned char *old_code,
unsigned char *new_code);
extern int ftrace_make_nop(struct module *mod,
struct dyn_ftrace *rec, unsigned long addr);
/**
* ftrace_make_call - convert a nop call site into a call to addr
* @rec: the mcount call site record
* @addr: the address that the call site should call
*
* This is a very sensitive operation and great care needs
* to be taken by the arch. The operation should carefully
* read the location, check to see if what is read is indeed
* what we expect it to be, and then on success of the compare,
* it should write to the location.
*
* The code segment at @rec->ip should be a nop
*
* Return must be:
* 0 on success
* -EFAULT on error reading the location
* -EINVAL on a failed compare of the contents
* -EPERM on error writing to the location
* Any other value will be considered a failure.
*/
extern int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr);
/* May be defined in arch */
extern int ftrace_arch_read_dyn_info(char *buf, int size);
extern int skip_trace(unsigned long ip);
@ -259,11 +300,13 @@ static inline void ftrace_dump(void) { }
#ifdef CONFIG_FTRACE_MCOUNT_RECORD
extern void ftrace_init(void);
extern void ftrace_init_module(unsigned long *start, unsigned long *end);
extern void ftrace_init_module(struct module *mod,
unsigned long *start, unsigned long *end);
#else
static inline void ftrace_init(void) { }
static inline void
ftrace_init_module(unsigned long *start, unsigned long *end) { }
ftrace_init_module(struct module *mod,
unsigned long *start, unsigned long *end) { }
#endif
@ -281,7 +324,7 @@ struct ftrace_retfunc {
/* Type of a callback handler of tracing return function */
typedef void (*trace_function_return_t)(struct ftrace_retfunc *);
extern void register_ftrace_return(trace_function_return_t func);
extern int register_ftrace_return(trace_function_return_t func);
/* The current handler in use */
extern trace_function_return_t ftrace_function_return;
extern void unregister_ftrace_return(void);

67
include/linux/marker.h
View File

@ -12,6 +12,7 @@
* See the file COPYING for more details.
*/
#include <stdarg.h>
#include <linux/types.h>
struct module;
@ -48,10 +49,28 @@ struct marker {
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.
@ -65,14 +84,7 @@ struct marker {
*/
#define __trace_mark(generic, name, call_private, format, args...) \
do { \
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 }; \
DEFINE_MARKER(name, format); \
__mark_check_format(format, ## args); \
if (unlikely(__mark_##name.state)) { \
(*__mark_##name.call) \
@ -80,14 +92,39 @@ struct marker {
} \
} 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 */
/**
@ -116,6 +153,20 @@ static inline void marker_update_probe_range(struct marker *begin,
#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.
*/

2
include/linux/rcupdate.h
View File

@ -142,6 +142,7 @@ struct rcu_head {
* on the write-side to insure proper synchronization.
*/
#define rcu_read_lock_sched() preempt_disable()
#define rcu_read_lock_sched_notrace() preempt_disable_notrace()
/*
* rcu_read_unlock_sched - marks the end of a RCU-classic critical section
@ -149,6 +150,7 @@ struct rcu_head {
* See rcu_read_lock_sched for more information.
*/
#define rcu_read_unlock_sched() preempt_enable()
#define rcu_read_unlock_sched_notrace() preempt_enable_notrace()

53
include/linux/tracepoint.h
View File

@ -24,8 +24,12 @@ struct tracepoint {
const char *name; /* Tracepoint name */
int state; /* State. */
void **funcs;
} __attribute__((aligned(8)));
} __attribute__((aligned(32))); /*
* Aligned on 32 bytes because it is
* globally visible and gcc happily
* align these on the structure size.
* Keep in sync with vmlinux.lds.h.
*/
#define TPPROTO(args...) args
#define TPARGS(args...) args
@ -40,14 +44,14 @@ struct tracepoint {
do { \
void **it_func; \
\
rcu_read_lock_sched(); \
rcu_read_lock_sched_notrace(); \
it_func = rcu_dereference((tp)->funcs); \
if (it_func) { \
do { \
((void(*)(proto))(*it_func))(args); \
} while (*(++it_func)); \
} \
rcu_read_unlock_sched(); \
rcu_read_unlock_sched_notrace(); \
} while (0)
/*
@ -55,35 +59,40 @@ struct tracepoint {
* not add unwanted padding between the beginning of the section and the
* structure. Force alignment to the same alignment as the section start.
*/
#define DEFINE_TRACE(name, proto, args) \
#define DECLARE_TRACE(name, proto, args) \
extern struct tracepoint __tracepoint_##name; \
static inline void trace_##name(proto) \
{ \
static const char __tpstrtab_##name[] \
__attribute__((section("__tracepoints_strings"))) \
= #name ":" #proto; \
static struct tracepoint __tracepoint_##name \
__attribute__((section("__tracepoints"), aligned(8))) = \
{ __tpstrtab_##name, 0, NULL }; \
if (unlikely(__tracepoint_##name.state)) \
__DO_TRACE(&__tracepoint_##name, \
TPPROTO(proto), TPARGS(args)); \
} \
static inline int register_trace_##name(void (*probe)(proto)) \
{ \
return tracepoint_probe_register(#name ":" #proto, \
(void *)probe); \
return tracepoint_probe_register(#name, (void *)probe); \
} \
static inline void unregister_trace_##name(void (*probe)(proto))\
static inline int unregister_trace_##name(void (*probe)(proto)) \
{ \
tracepoint_probe_unregister(#name ":" #proto, \
(void *)probe); \
return tracepoint_probe_unregister(#name, (void *)probe);\
}
#define DEFINE_TRACE(name) \
static const char __tpstrtab_##name[] \
__attribute__((section("__tracepoints_strings"))) = #name; \
struct tracepoint __tracepoint_##name \
__attribute__((section("__tracepoints"), aligned(32))) = \
{ __tpstrtab_##name, 0, NULL }
#define EXPORT_TRACEPOINT_SYMBOL_GPL(name) \
EXPORT_SYMBOL_GPL(__tracepoint_##name)
#define EXPORT_TRACEPOINT_SYMBOL(name) \
EXPORT_SYMBOL(__tracepoint_##name)
extern void tracepoint_update_probe_range(struct tracepoint *begin,
struct tracepoint *end);
#else /* !CONFIG_TRACEPOINTS */
#define DEFINE_TRACE(name, proto, args) \
#define DECLARE_TRACE(name, proto, args) \
static inline void _do_trace_##name(struct tracepoint *tp, proto) \
{ } \
static inline void trace_##name(proto) \
@ -92,8 +101,14 @@ extern void tracepoint_update_probe_range(struct tracepoint *begin,
{ \
return -ENOSYS; \
} \
static inline void unregister_trace_##name(void (*probe)(proto))\
{ }
static inline int unregister_trace_##name(void (*probe)(proto)) \
{ \
return -ENOSYS; \
}
#define DEFINE_TRACE(name)
#define EXPORT_TRACEPOINT_SYMBOL_GPL(name)
#define EXPORT_TRACEPOINT_SYMBOL(name)
static inline void tracepoint_update_probe_range(struct tracepoint *begin,
struct tracepoint *end)

24
include/trace/sched.h
View File

@ -4,52 +4,52 @@
#include <linux/sched.h>
#include <linux/tracepoint.h>
DEFINE_TRACE(sched_kthread_stop,
DECLARE_TRACE(sched_kthread_stop,
TPPROTO(struct task_struct *t),
TPARGS(t));
DEFINE_TRACE(sched_kthread_stop_ret,
DECLARE_TRACE(sched_kthread_stop_ret,
TPPROTO(int ret),
TPARGS(ret));
DEFINE_TRACE(sched_wait_task,
DECLARE_TRACE(sched_wait_task,
TPPROTO(struct rq *rq, struct task_struct *p),
TPARGS(rq, p));
DEFINE_TRACE(sched_wakeup,
DECLARE_TRACE(sched_wakeup,
TPPROTO(struct rq *rq, struct task_struct *p),
TPARGS(rq, p));
DEFINE_TRACE(sched_wakeup_new,
DECLARE_TRACE(sched_wakeup_new,
TPPROTO(struct rq *rq, struct task_struct *p),
TPARGS(rq, p));
DEFINE_TRACE(sched_switch,
DECLARE_TRACE(sched_switch,
TPPROTO(struct rq *rq, struct task_struct *prev,
struct task_struct *next),
TPARGS(rq, prev, next));
DEFINE_TRACE(sched_migrate_task,
DECLARE_TRACE(sched_migrate_task,
TPPROTO(struct rq *rq, struct task_struct *p, int dest_cpu),
TPARGS(rq, p, dest_cpu));
DEFINE_TRACE(sched_process_free,
DECLARE_TRACE(sched_process_free,
TPPROTO(struct task_struct *p),
TPARGS(p));
DEFINE_TRACE(sched_process_exit,
DECLARE_TRACE(sched_process_exit,
TPPROTO(struct task_struct *p),
TPARGS(p));
DEFINE_TRACE(sched_process_wait,
DECLARE_TRACE(sched_process_wait,
TPPROTO(struct pid *pid),
TPARGS(pid));
DEFINE_TRACE(sched_process_fork,
DECLARE_TRACE(sched_process_fork,
TPPROTO(struct task_struct *parent, struct task_struct *child),
TPARGS(parent, child));
DEFINE_TRACE(sched_signal_send,
DECLARE_TRACE(sched_signal_send,
TPPROTO(int sig, struct task_struct *p),
TPARGS(sig, p));

1
init/Kconfig
View File

@ -808,6 +808,7 @@ config TRACEPOINTS
config MARKERS
bool "Activate markers"
depends on TRACEPOINTS
help
Place an empty function call at each marker site. Can be
dynamically changed for a probe function.

4
kernel/exit.c
View File

@ -54,6 +54,10 @@
#include <asm/pgtable.h>
#include <asm/mmu_context.h>
DEFINE_TRACE(sched_process_free);
DEFINE_TRACE(sched_process_exit);
DEFINE_TRACE(sched_process_wait);
static void exit_mm(struct task_struct * tsk);
static inline int task_detached(struct task_struct *p)

2
kernel/fork.c
View File

@ -79,6 +79,8 @@ DEFINE_PER_CPU(unsigned long, process_counts) = 0;
__cacheline_aligned DEFINE_RWLOCK(tasklist_lock); /* outer */
DEFINE_TRACE(sched_process_fork);
int nr_processes(void)
{
int cpu;

3
kernel/kthread.c
View File

@ -21,6 +21,9 @@ static DEFINE_SPINLOCK(kthread_create_lock);
static LIST_HEAD(kthread_create_list);
struct task_struct *kthreadd_task;
DEFINE_TRACE(sched_kthread_stop);
DEFINE_TRACE(sched_kthread_stop_ret);
struct kthread_create_info
{
/* Information passed to kthread() from kthreadd. */

114
kernel/marker.c
View File

@ -81,7 +81,7 @@ struct marker_entry {
* though the function pointer change and the marker enabling are two distinct
* operations that modifies the execution flow of preemptible code.
*/
void __mark_empty_function(void *probe_private, void *call_private,
notrace void __mark_empty_function(void *probe_private, void *call_private,
const char *fmt, va_list *args)
{
}
@ -97,7 +97,8 @@ EXPORT_SYMBOL_GPL(__mark_empty_function);
* need to put a full smp_rmb() in this branch. This is why we do not use
* rcu_dereference() for the pointer read.
*/
void marker_probe_cb(const struct marker *mdata, void *call_private, ...)
notrace void marker_probe_cb(const struct marker *mdata,
void *call_private, ...)
{
va_list args;
char ptype;
@ -107,7 +108,7 @@ void marker_probe_cb(const struct marker *mdata, void *call_private, ...)
* 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();
rcu_read_lock_sched_notrace();
ptype = mdata->ptype;
if (likely(!ptype)) {
marker_probe_func *func;
@ -145,7 +146,7 @@ void marker_probe_cb(const struct marker *mdata, void *call_private, ...)
va_end(args);
}
}
rcu_read_unlock_sched();
rcu_read_unlock_sched_notrace();
}
EXPORT_SYMBOL_GPL(marker_probe_cb);
@ -157,12 +158,13 @@ EXPORT_SYMBOL_GPL(marker_probe_cb);
*
* Should be connected to markers "MARK_NOARGS".
*/
static void marker_probe_cb_noarg(const struct marker *mdata, void *call_private, ...)
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();
rcu_read_lock_sched_notrace();
ptype = mdata->ptype;
if (likely(!ptype)) {
marker_probe_func *func;
@ -195,7 +197,7 @@ static void marker_probe_cb_noarg(const struct marker *mdata, void *call_private
multi[i].func(multi[i].probe_private, call_private,
mdata->format, &args);
}
rcu_read_unlock_sched();
rcu_read_unlock_sched_notrace();
}
static void free_old_closure(struct rcu_head *head)
@ -477,7 +479,7 @@ static int marker_set_format(struct marker_entry *entry, const char *format)
static int set_marker(struct marker_entry *entry, struct marker *elem,
int active)
{
int ret;
int ret = 0;
WARN_ON(strcmp(entry->name, elem->name) != 0);
if (entry->format) {
@ -529,9 +531,40 @@ static int set_marker(struct marker_entry *entry, struct marker *elem,
*/
smp_wmb();
elem->ptype = entry->ptype;
if (elem->tp_name && (active ^ elem->state)) {
WARN_ON(!elem->tp_cb);
/*
* It is ok to directly call the probe registration because type
* checking has been done in the __trace_mark_tp() macro.
*/
if (active) {
/*
* try_module_get should always succeed because we hold
* lock_module() to get the tp_cb address.
*/
ret = try_module_get(__module_text_address(
(unsigned long)elem->tp_cb));
BUG_ON(!ret);
ret = tracepoint_probe_register_noupdate(
elem->tp_name,
elem->tp_cb);
} else {
ret = tracepoint_probe_unregister_noupdate(
elem->tp_name,
elem->tp_cb);
/*
* tracepoint_probe_update_all() must be called
* before the module containing tp_cb is unloaded.
*/
module_put(__module_text_address(
(unsigned long)elem->tp_cb));
}
}
elem->state = active;
return 0;
return ret;
}
/*
@ -542,7 +575,24 @@ static int set_marker(struct marker_entry *entry, struct marker *elem,
*/
static void disable_marker(struct marker *elem)
{
int ret;
/* leave "call" as is. It is known statically. */
if (elem->tp_name && elem->state) {
WARN_ON(!elem->tp_cb);
/*
* It is ok to directly call the probe registration because type
* checking has been done in the __trace_mark_tp() macro.
*/
ret = tracepoint_probe_unregister_noupdate(elem->tp_name,
elem->tp_cb);
WARN_ON(ret);
/*
* tracepoint_probe_update_all() must be called
* before the module containing tp_cb is unloaded.
*/
module_put(__module_text_address((unsigned long)elem->tp_cb));
}
elem->state = 0;
elem->single.func = __mark_empty_function;
/* Update the function before setting the ptype */
@ -606,6 +656,7 @@ static void marker_update_probes(void)
marker_update_probe_range(__start___markers, __stop___markers);
/* Markers in modules. */
module_update_markers();
tracepoint_probe_update_all();
}
/**
@ -653,10 +704,11 @@ int marker_probe_register(const char *name, const char *format,
goto end;
}
mutex_unlock(&markers_mutex);
marker_update_probes(); /* may update entry */
marker_update_probes();
mutex_lock(&markers_mutex);
entry = get_marker(name);
WARN_ON(!entry);
if (!entry)
goto end;
if (entry->rcu_pending)
rcu_barrier_sched();
entry->oldptr = old;
@ -697,7 +749,7 @@ int marker_probe_unregister(const char *name,
rcu_barrier_sched();
old = marker_entry_remove_probe(entry, probe, probe_private);
mutex_unlock(&markers_mutex);
marker_update_probes(); /* may update entry */
marker_update_probes();
mutex_lock(&markers_mutex);
entry = get_marker(name);
if (!entry)
@ -778,10 +830,11 @@ int marker_probe_unregister_private_data(marker_probe_func *probe,
rcu_barrier_sched();
old = marker_entry_remove_probe(entry, NULL, probe_private);
mutex_unlock(&markers_mutex);
marker_update_probes(); /* may update entry */
marker_update_probes();
mutex_lock(&markers_mutex);
entry = get_marker_from_private_data(probe, probe_private);
WARN_ON(!entry);
if (!entry)
goto end;
if (entry->rcu_pending)
rcu_barrier_sched();
entry->oldptr = old;
@ -842,3 +895,36 @@ void *marker_get_private_data(const char *name, marker_probe_func *probe,
return ERR_PTR(-ENOENT);
}
EXPORT_SYMBOL_GPL(marker_get_private_data);
#ifdef CONFIG_MODULES
int marker_module_notify(struct notifier_block *self,
unsigned long val, void *data)
{
struct module *mod = data;
switch (val) {
case MODULE_STATE_COMING:
marker_update_probe_range(mod->markers,
mod->markers + mod->num_markers);
break;
case MODULE_STATE_GOING:
marker_update_probe_range(mod->markers,
mod->markers + mod->num_markers);
break;
}
return 0;
}
struct notifier_block marker_module_nb = {
.notifier_call = marker_module_notify,
.priority = 0,
};
static int init_markers(void)
{
return register_module_notifier(&marker_module_nb);
}
__initcall(init_markers);
#endif /* CONFIG_MODULES */

11
kernel/module.c
View File

@ -2184,24 +2184,15 @@ static noinline struct module *load_module(void __user *umod,
struct mod_debug *debug;
unsigned int num_debug;
#ifdef CONFIG_MARKERS
marker_update_probe_range(mod->markers,
mod->markers + mod->num_markers);
#endif
debug = section_objs(hdr, sechdrs, secstrings, "__verbose",
sizeof(*debug), &num_debug);
dynamic_printk_setup(debug, num_debug);
#ifdef CONFIG_TRACEPOINTS
tracepoint_update_probe_range(mod->tracepoints,
mod->tracepoints + mod->num_tracepoints);
#endif
}
/* sechdrs[0].sh_size is always zero */
mseg = section_objs(hdr, sechdrs, secstrings, "__mcount_loc",
sizeof(*mseg), &num_mcount);
ftrace_init_module(mseg, mseg + num_mcount);
ftrace_init_module(mod, mseg, mseg + num_mcount);
err = module_finalize(hdr, sechdrs, mod);
if (err < 0)

6
kernel/sched.c
View File

@ -118,6 +118,12 @@
*/
#define RUNTIME_INF ((u64)~0ULL)
DEFINE_TRACE(sched_wait_task);
DEFINE_TRACE(sched_wakeup);
DEFINE_TRACE(sched_wakeup_new);
DEFINE_TRACE(sched_switch);
DEFINE_TRACE(sched_migrate_task);
#ifdef CONFIG_SMP
/*
* Divide a load by a sched group cpu_power : (load / sg->__cpu_power)

2
kernel/signal.c
View File

@ -41,6 +41,8 @@
static struct kmem_cache *sigqueue_cachep;
DEFINE_TRACE(sched_signal_send);
static void __user *sig_handler(struct task_struct *t, int sig)
{
return t->sighand->action[sig - 1].sa.sa_handler;

1
kernel/trace/Kconfig
View File

@ -59,7 +59,6 @@ config FUNCTION_TRACER
config FUNCTION_RET_TRACER
bool "Kernel Function return Tracer"
depends on !DYNAMIC_FTRACE
depends on HAVE_FUNCTION_RET_TRACER
depends on FUNCTION_TRACER
help

404
kernel/trace/ftrace.c
View File

@ -50,6 +50,9 @@ static int last_ftrace_enabled;
/* Quick disabling of function tracer. */
int function_trace_stop;
/* By default, current tracing type is normal tracing. */
enum ftrace_tracing_type_t ftrace_tracing_type = FTRACE_TYPE_ENTER;
/*
* ftrace_disabled is set when an anomaly is discovered.
* ftrace_disabled is much stronger than ftrace_enabled.
@ -334,7 +337,7 @@ ftrace_record_ip(unsigned long ip)
{
struct dyn_ftrace *rec;
if (!ftrace_enabled || ftrace_disabled)
if (ftrace_disabled)
return NULL;
rec = ftrace_alloc_dyn_node(ip);
@ -348,129 +351,6 @@ ftrace_record_ip(unsigned long ip)
return rec;
}
#define FTRACE_ADDR ((long)(ftrace_caller))
static int
__ftrace_replace_code(struct dyn_ftrace *rec,
unsigned char *old, unsigned char *new, int enable)
{
unsigned long ip, fl;
ip = rec->ip;
if (ftrace_filtered && enable) {
/*
* If filtering is on:
*
* If this record is set to be filtered and
* is enabled then do nothing.
*
* If this record is set to be filtered and
* it is not enabled, enable it.
*
* If this record is not set to be filtered
* and it is not enabled do nothing.
*
* If this record is set not to trace then
* do nothing.
*
* If this record is set not to trace and
* it is enabled then disable it.
*
* If this record is not set to be filtered and
* it is enabled, disable it.
*/
fl = rec->flags & (FTRACE_FL_FILTER | FTRACE_FL_NOTRACE |
FTRACE_FL_ENABLED);
if ((fl == (FTRACE_FL_FILTER | FTRACE_FL_ENABLED)) ||
(fl == (FTRACE_FL_FILTER | FTRACE_FL_NOTRACE)) ||
!fl || (fl == FTRACE_FL_NOTRACE))
return 0;
/*
* If it is enabled disable it,
* otherwise enable it!
*/
if (fl & FTRACE_FL_ENABLED) {
/* swap new and old */
new = old;
old = ftrace_call_replace(ip, FTRACE_ADDR);
rec->flags &= ~FTRACE_FL_ENABLED;
} else {
new = ftrace_call_replace(ip, FTRACE_ADDR);
rec->flags |= FTRACE_FL_ENABLED;
}
} else {
if (enable) {
/*
* If this record is set not to trace and is
* not enabled, do nothing.
*/
fl = rec->flags & (FTRACE_FL_NOTRACE | FTRACE_FL_ENABLED);
if (fl == FTRACE_FL_NOTRACE)
return 0;
new = ftrace_call_replace(ip, FTRACE_ADDR);
} else
old = ftrace_call_replace(ip, FTRACE_ADDR);
if (enable) {
if (rec->flags & FTRACE_FL_ENABLED)
return 0;
rec->flags |= FTRACE_FL_ENABLED;
} else {
if (!(rec->flags & FTRACE_FL_ENABLED))
return 0;
rec->flags &= ~FTRACE_FL_ENABLED;
}
}
return ftrace_modify_code(ip, old, new);
}
static void ftrace_replace_code(int enable)
{
int i, failed;
unsigned char *new = NULL, *old = NULL;
struct dyn_ftrace *rec;
struct ftrace_page *pg;
if (enable)
old = ftrace_nop_replace();
else
new = ftrace_nop_replace();
for (pg = ftrace_pages_start; pg; pg = pg->next) {
for (i = 0; i < pg->index; i++) {
rec = &pg->records[i];
/* don't modify code that has already faulted */
if (rec->flags & FTRACE_FL_FAILED)
continue;
/* ignore updates to this record's mcount site */
if (get_kprobe((void *)rec->ip)) {
freeze_record(rec);
continue;
} else {
unfreeze_record(rec);
}
failed = __ftrace_replace_code(rec, old, new, enable);
if (failed && (rec->flags & FTRACE_FL_CONVERTED)) {
rec->flags |= FTRACE_FL_FAILED;
if ((system_state == SYSTEM_BOOTING) ||
!core_kernel_text(rec->ip)) {
ftrace_free_rec(rec);
}
}
}
}
}
static void print_ip_ins(const char *fmt, unsigned char *p)
{
int i;
@ -481,46 +361,162 @@ static void print_ip_ins(const char *fmt, unsigned char *p)
printk(KERN_CONT "%s%02x", i ? ":" : "", p[i]);
}
static void ftrace_bug(int failed, unsigned long ip)
{
switch (failed) {
case -EFAULT:
FTRACE_WARN_ON_ONCE(1);
pr_info("ftrace faulted on modifying ");
print_ip_sym(ip);
break;
case -EINVAL:
FTRACE_WARN_ON_ONCE(1);
pr_info("ftrace failed to modify ");
print_ip_sym(ip);
print_ip_ins(" actual: ", (unsigned char *)ip);
printk(KERN_CONT "\n");
break;
case -EPERM:
FTRACE_WARN_ON_ONCE(1);
pr_info("ftrace faulted on writing ");
print_ip_sym(ip);
break;
default:
FTRACE_WARN_ON_ONCE(1);
pr_info("ftrace faulted on unknown error ");
print_ip_sym(ip);
}
}
static int
ftrace_code_disable(struct dyn_ftrace *rec)
__ftrace_replace_code(struct dyn_ftrace *rec, int enable)
{
unsigned long ip, fl;
unsigned long ftrace_addr;
#ifdef CONFIG_FUNCTION_RET_TRACER
if (ftrace_tracing_type == FTRACE_TYPE_ENTER)
ftrace_addr = (unsigned long)ftrace_caller;
else
ftrace_addr = (unsigned long)ftrace_return_caller;
#else
ftrace_addr = (unsigned long)ftrace_caller;
#endif
ip = rec->ip;
/*
* If this record is not to be traced and
* it is not enabled then do nothing.
*
* If this record is not to be traced and
* it is enabled then disabled it.
*
*/
if (rec->flags & FTRACE_FL_NOTRACE) {
if (rec->flags & FTRACE_FL_ENABLED)
rec->flags &= ~FTRACE_FL_ENABLED;
else
return 0;
} else if (ftrace_filtered && enable) {
/*
* Filtering is on:
*/
fl = rec->flags & (FTRACE_FL_FILTER | FTRACE_FL_ENABLED);
/* Record is filtered and enabled, do nothing */
if (fl == (FTRACE_FL_FILTER | FTRACE_FL_ENABLED))
return 0;
/* Record is not filtered and is not enabled do nothing */
if (!fl)
return 0;
/* Record is not filtered but enabled, disable it */
if (fl == FTRACE_FL_ENABLED)
rec->flags &= ~FTRACE_FL_ENABLED;
else
/* Otherwise record is filtered but not enabled, enable it */
rec->flags |= FTRACE_FL_ENABLED;
} else {
/* Disable or not filtered */
if (enable) {
/* if record is enabled, do nothing */
if (rec->flags & FTRACE_FL_ENABLED)
return 0;
rec->flags |= FTRACE_FL_ENABLED;
} else {
/* if record is not enabled do nothing */
if (!(rec->flags & FTRACE_FL_ENABLED))
return 0;
rec->flags &= ~FTRACE_FL_ENABLED;
}
}
if (rec->flags & FTRACE_FL_ENABLED)
return ftrace_make_call(rec, ftrace_addr);
else
return ftrace_make_nop(NULL, rec, ftrace_addr);
}
static void ftrace_replace_code(int enable)
{
int i, failed;
struct dyn_ftrace *rec;
struct ftrace_page *pg;
for (pg = ftrace_pages_start; pg; pg = pg->next) {
for (i = 0; i < pg->index; i++) {
rec = &pg->records[i];
/*
* Skip over free records and records that have
* failed.
*/
if (rec->flags & FTRACE_FL_FREE ||
rec->flags & FTRACE_FL_FAILED)
continue;
/* ignore updates to this record's mcount site */
if (get_kprobe((void *)rec->ip)) {
freeze_record(rec);
continue;
} else {
unfreeze_record(rec);
}
failed = __ftrace_replace_code(rec, enable);
if (failed && (rec->flags & FTRACE_FL_CONVERTED)) {
rec->flags |= FTRACE_FL_FAILED;
if ((system_state == SYSTEM_BOOTING) ||
!core_kernel_text(rec->ip)) {
ftrace_free_rec(rec);
} else
ftrace_bug(failed, rec->ip);
}
}
}
}
static int
ftrace_code_disable(struct module *mod, struct dyn_ftrace *rec)
{
unsigned long ip;
unsigned char *nop, *call;
int ret;
ip = rec->ip;
nop = ftrace_nop_replace();
call = ftrace_call_replace(ip, mcount_addr);
ret = ftrace_modify_code(ip, call, nop);
ret = ftrace_make_nop(mod, rec, mcount_addr);
if (ret) {
switch (ret) {
case -EFAULT:
FTRACE_WARN_ON_ONCE(1);
pr_info("ftrace faulted on modifying ");
print_ip_sym(ip);
break;
case -EINVAL:
FTRACE_WARN_ON_ONCE(1);
pr_info("ftrace failed to modify ");
print_ip_sym(ip);
print_ip_ins(" expected: ", call);
print_ip_ins(" actual: ", (unsigned char *)ip);
print_ip_ins(" replace: ", nop);
printk(KERN_CONT "\n");
break;
case -EPERM:
FTRACE_WARN_ON_ONCE(1);
pr_info("ftrace faulted on writing ");
print_ip_sym(ip);
break;
default:
FTRACE_WARN_ON_ONCE(1);
pr_info("ftrace faulted on unknown error ");
print_ip_sym(ip);
}
ftrace_bug(ret, ip);
rec->flags |= FTRACE_FL_FAILED;
return 0;
}
@ -560,8 +556,7 @@ static void ftrace_startup(void)
mutex_lock(&ftrace_start_lock);
ftrace_start_up++;
if (ftrace_start_up == 1)
command |= FTRACE_ENABLE_CALLS;
command |= FTRACE_ENABLE_CALLS;
if (saved_ftrace_func != ftrace_trace_function) {
saved_ftrace_func = ftrace_trace_function;
@ -639,7 +634,7 @@ static cycle_t ftrace_update_time;
static unsigned long ftrace_update_cnt;
unsigned long ftrace_update_tot_cnt;
static int ftrace_update_code(void)
static int ftrace_update_code(struct module *mod)
{
struct dyn_ftrace *p, *t;
cycle_t start, stop;
@ -656,7 +651,7 @@ static int ftrace_update_code(void)
list_del_init(&p->list);
/* convert record (i.e, patch mcount-call with NOP) */
if (ftrace_code_disable(p)) {
if (ftrace_code_disable(mod, p)) {
p->flags |= FTRACE_FL_CONVERTED;
ftrace_update_cnt++;
} else
@ -699,7 +694,7 @@ static int __init ftrace_dyn_table_alloc(unsigned long num_to_init)
cnt = num_to_init / ENTRIES_PER_PAGE;
pr_info("ftrace: allocating %ld entries in %d pages\n",
num_to_init, cnt);
num_to_init, cnt + 1);
for (i = 0; i < cnt; i++) {
pg->next = (void *)get_zeroed_page(GFP_KERNEL);
@ -782,13 +777,11 @@ static void *t_start(struct seq_file *m, loff_t *pos)
void *p = NULL;
loff_t l = -1;
if (*pos != iter->pos) {
for (p = t_next(m, p, &l); p && l < *pos; p = t_next(m, p, &l))
;
} else {
l = *pos;
p = t_next(m, p, &l);
}
if (*pos > iter->pos)
*pos = iter->pos;
l = *pos;
p = t_next(m, p, &l);
return p;
}
@ -799,15 +792,21 @@ static void t_stop(struct seq_file *m, void *p)
static int t_show(struct seq_file *m, void *v)
{
struct ftrace_iterator *iter = m->private;
struct dyn_ftrace *rec = v;
char str[KSYM_SYMBOL_LEN];
int ret = 0;
if (!rec)
return 0;
kallsyms_lookup(rec->ip, NULL, NULL, NULL, str);
seq_printf(m, "%s\n", str);
ret = seq_printf(m, "%s\n", str);
if (ret < 0) {
iter->pos--;
iter->idx--;
}
return 0;
}
@ -833,7 +832,7 @@ ftrace_avail_open(struct inode *inode, struct file *file)
return -ENOMEM;
iter->pg = ftrace_pages_start;
iter->pos = -1;
iter->pos = 0;
ret = seq_open(file, &show_ftrace_seq_ops);
if (!ret) {
@ -920,7 +919,7 @@ ftrace_regex_open(struct inode *inode, struct file *file, int enable)
if (file->f_mode & FMODE_READ) {
iter->pg = ftrace_pages_start;
iter->pos = -1;
iter->pos = 0;
iter->flags = enable ? FTRACE_ITER_FILTER :
FTRACE_ITER_NOTRACE;
@ -1211,7 +1210,7 @@ ftrace_regex_release(struct inode *inode, struct file *file, int enable)
mutex_lock(&ftrace_sysctl_lock);
mutex_lock(&ftrace_start_lock);
if (iter->filtered && ftrace_start_up && ftrace_enabled)
if (ftrace_start_up && ftrace_enabled)
ftrace_run_update_code(FTRACE_ENABLE_CALLS);
mutex_unlock(&ftrace_start_lock);
mutex_unlock(&ftrace_sysctl_lock);
@ -1298,7 +1297,8 @@ static __init int ftrace_init_debugfs(void)
fs_initcall(ftrace_init_debugfs);
static int ftrace_convert_nops(unsigned long *start,
static int ftrace_convert_nops(struct module *mod,
unsigned long *start,
unsigned long *end)
{
unsigned long *p;
@ -1309,23 +1309,32 @@ static int ftrace_convert_nops(unsigned long *start,
p = start;
while (p < end) {
addr = ftrace_call_adjust(*p++);
/*
* Some architecture linkers will pad between
* the different mcount_loc sections of different
* object files to satisfy alignments.
* Skip any NULL pointers.
*/
if (!addr)
continue;
ftrace_record_ip(addr);
}
/* disable interrupts to prevent kstop machine */
local_irq_save(flags);
ftrace_update_code();
ftrace_update_code(mod);
local_irq_restore(flags);
mutex_unlock(&ftrace_start_lock);
return 0;
}
void ftrace_init_module(unsigned long *start, unsigned long *end)
void ftrace_init_module(struct module *mod,
unsigned long *start, unsigned long *end)
{
if (ftrace_disabled || start == end)
return;
ftrace_convert_nops(start, end);
ftrace_convert_nops(mod, start, end);
}
extern unsigned long __start_mcount_loc[];
@ -1355,7 +1364,8 @@ void __init ftrace_init(void)
last_ftrace_enabled = ftrace_enabled = 1;
ret = ftrace_convert_nops(__start_mcount_loc,
ret = ftrace_convert_nops(NULL,
__start_mcount_loc,
__stop_mcount_loc);
return;
@ -1411,10 +1421,17 @@ int register_ftrace_function(struct ftrace_ops *ops)
return -1;
mutex_lock(&ftrace_sysctl_lock);
if (ftrace_tracing_type == FTRACE_TYPE_RETURN) {
ret = -EBUSY;
goto out;
}
ret = __register_ftrace_function(ops);
ftrace_startup();
mutex_unlock(&ftrace_sysctl_lock);
out:
mutex_unlock(&ftrace_sysctl_lock);
return ret;
}
@ -1480,16 +1497,45 @@ ftrace_enable_sysctl(struct ctl_table *table, int write,
}
#ifdef CONFIG_FUNCTION_RET_TRACER
/* The callback that hooks the return of a function */
trace_function_return_t ftrace_function_return =
(trace_function_return_t)ftrace_stub;
void register_ftrace_return(trace_function_return_t func)
int register_ftrace_return(trace_function_return_t func)
{
int ret = 0;
mutex_lock(&ftrace_sysctl_lock);
/*
* Don't launch return tracing if normal function
* tracing is already running.
*/
if (ftrace_trace_function != ftrace_stub) {
ret = -EBUSY;
goto out;
}
ftrace_tracing_type = FTRACE_TYPE_RETURN;
ftrace_function_return = func;
ftrace_startup();
out:
mutex_unlock(&ftrace_sysctl_lock);
return ret;
}
void unregister_ftrace_return(void)
{
mutex_lock(&ftrace_sysctl_lock);
ftrace_function_return = (trace_function_return_t)ftrace_stub;
ftrace_shutdown();
/* Restore normal tracing type */
ftrace_tracing_type = FTRACE_TYPE_ENTER;
mutex_unlock(&ftrace_sysctl_lock);
}
#endif

23
kernel/trace/trace.c
View File

@ -1051,7 +1051,7 @@ function_trace_call(unsigned long ip, unsigned long parent_ip)
* Need to use raw, since this must be called before the
* recursive protection is performed.
*/
raw_local_irq_save(flags);
local_irq_save(flags);
cpu = raw_smp_processor_id();
data = tr->data[cpu];
disabled = atomic_inc_return(&data->disabled);
@ -1062,7 +1062,7 @@ function_trace_call(unsigned long ip, unsigned long parent_ip)
}
atomic_dec(&data->disabled);
raw_local_irq_restore(flags);
local_irq_restore(flags);
}
#ifdef CONFIG_FUNCTION_RET_TRACER
@ -2638,8 +2638,11 @@ static int tracing_set_tracer(char *buf)
current_trace->reset(tr);
current_trace = t;
if (t->init)
t->init(tr);
if (t->init) {
ret = t->init(tr);
if (ret)
goto out;
}
trace_branch_enable(tr);
out:
@ -2655,6 +2658,9 @@ tracing_set_trace_write(struct file *filp, const char __user *ubuf,
char buf[max_tracer_type_len+1];
int i;
size_t ret;
int err;
ret = cnt;
if (cnt > max_tracer_type_len)
cnt = max_tracer_type_len;
@ -2668,12 +2674,11 @@ tracing_set_trace_write(struct file *filp, const char __user *ubuf,
for (i = cnt - 1; i > 0 && isspace(buf[i]); i--)
buf[i] = 0;
ret = tracing_set_tracer(buf);
if (!ret)
ret = cnt;
err = tracing_set_tracer(buf);
if (err)
return err;
if (ret > 0)
filp->f_pos += ret;
filp->f_pos += ret;
return ret;
}

3
kernel/trace/trace.h
View File

@ -264,7 +264,8 @@ enum print_line_t {
*/
struct tracer {
const char *name;
void (*init)(struct trace_array *tr);
/* Your tracer should raise a warning if init fails */
int (*init)(struct trace_array *tr);
void (*reset)(struct trace_array *tr);
void (*start)(struct trace_array *tr);
void (*stop)(struct trace_array *tr);

3
kernel/trace/trace_boot.c
View File

@ -47,7 +47,7 @@ static void reset_boot_trace(struct trace_array *tr)
tracing_reset(tr, cpu);
}
static void boot_trace_init(struct trace_array *tr)
static int boot_trace_init(struct trace_array *tr)
{
int cpu;
boot_trace = tr;
@ -56,6 +56,7 @@ static void boot_trace_init(struct trace_array *tr)
tracing_reset(tr, cpu);
tracing_sched_switch_assign_trace(tr);
return 0;
}
static enum print_line_t

3
kernel/trace/trace_branch.c
View File

@ -125,7 +125,7 @@ static void stop_branch_trace(struct trace_array *tr)
disable_branch_tracing();
}
static void branch_trace_init(struct trace_array *tr)
static int branch_trace_init(struct trace_array *tr)
{
int cpu;
@ -133,6 +133,7 @@ static void branch_trace_init(struct trace_array *tr)
tracing_reset(tr, cpu);
start_branch_trace(tr);
return 0;
}
static void branch_trace_reset(struct trace_array *tr)

3
kernel/trace/trace_functions.c
View File

@ -42,9 +42,10 @@ static void stop_function_trace(struct trace_array *tr)
tracing_stop_cmdline_record();
}
static void function_trace_init(struct trace_array *tr)
static int function_trace_init(struct trace_array *tr)
{
start_function_trace(tr);
return 0;
}
static void function_trace_reset(struct trace_array *tr)

16
kernel/trace/trace_functions_return.c
View File

@ -14,28 +14,18 @@
#include "trace.h"
static void start_return_trace(struct trace_array *tr)
{
register_ftrace_return(&trace_function_return);
}
static void stop_return_trace(struct trace_array *tr)
{
unregister_ftrace_return();
}
static void return_trace_init(struct trace_array *tr)
static int return_trace_init(struct trace_array *tr)
{
int cpu;
for_each_online_cpu(cpu)
tracing_reset(tr, cpu);
start_return_trace(tr);
return register_ftrace_return(&trace_function_return);
}
static void return_trace_reset(struct trace_array *tr)
{
stop_return_trace(tr);
unregister_ftrace_return();
}

9
kernel/trace/trace_irqsoff.c
View File

@ -416,11 +416,12 @@ static void irqsoff_tracer_close(struct trace_iterator *iter)
}
#ifdef CONFIG_IRQSOFF_TRACER
static void irqsoff_tracer_init(struct trace_array *tr)
static int irqsoff_tracer_init(struct trace_array *tr)
{
trace_type = TRACER_IRQS_OFF;
__irqsoff_tracer_init(tr);
return 0;
}
static struct tracer irqsoff_tracer __read_mostly =
{
@ -442,11 +443,12 @@ static struct tracer irqsoff_tracer __read_mostly =
#endif
#ifdef CONFIG_PREEMPT_TRACER
static void preemptoff_tracer_init(struct trace_array *tr)
static int preemptoff_tracer_init(struct trace_array *tr)
{
trace_type = TRACER_PREEMPT_OFF;
__irqsoff_tracer_init(tr);
return 0;
}
static struct tracer preemptoff_tracer __read_mostly =
@ -471,11 +473,12 @@ static struct tracer preemptoff_tracer __read_mostly =
#if defined(CONFIG_IRQSOFF_TRACER) && \
defined(CONFIG_PREEMPT_TRACER)
static void preemptirqsoff_tracer_init(struct trace_array *tr)
static int preemptirqsoff_tracer_init(struct trace_array *tr)
{
trace_type = TRACER_IRQS_OFF | TRACER_PREEMPT_OFF;
__irqsoff_tracer_init(tr);
return 0;
}
static struct tracer preemptirqsoff_tracer __read_mostly =

3
kernel/trace/trace_mmiotrace.c
View File

@ -30,13 +30,14 @@ static void mmio_reset_data(struct trace_array *tr)
tracing_reset(tr, cpu);
}
static void mmio_trace_init(struct trace_array *tr)
static int mmio_trace_init(struct trace_array *tr)
{
pr_debug("in %s\n", __func__);
mmio_trace_array = tr;
mmio_reset_data(tr);
enable_mmiotrace();
return 0;
}
static void mmio_trace_reset(struct trace_array *tr)

3
kernel/trace/trace_nop.c
View File

@ -24,7 +24,7 @@ static void stop_nop_trace(struct trace_array *tr)
/* Nothing to do! */
}
static void nop_trace_init(struct trace_array *tr)
static int nop_trace_init(struct trace_array *tr)
{
int cpu;
ctx_trace = tr;
@ -33,6 +33,7 @@ static void nop_trace_init(struct trace_array *tr)
tracing_reset(tr, cpu);
start_nop_trace(tr);
return 0;
}
static void nop_trace_reset(struct trace_array *tr)

3
kernel/trace/trace_sched_switch.c
View File

@ -206,10 +206,11 @@ static void stop_sched_trace(struct trace_array *tr)
tracing_stop_sched_switch_record();
}
static void sched_switch_trace_init(struct trace_array *tr)
static int sched_switch_trace_init(struct trace_array *tr)
{
ctx_trace = tr;
start_sched_trace(tr);
return 0;
}
static void sched_switch_trace_reset(struct trace_array *tr)

3
kernel/trace/trace_sched_wakeup.c
View File

@ -331,10 +331,11 @@ static void stop_wakeup_tracer(struct trace_array *tr)
unregister_trace_sched_wakeup(probe_wakeup);
}
static void wakeup_tracer_init(struct trace_array *tr)
static int wakeup_tracer_init(struct trace_array *tr)
{
wakeup_trace = tr;
start_wakeup_tracer(tr);
return 0;
}
static void wakeup_tracer_reset(struct trace_array *tr)

70
kernel/trace/trace_selftest.c
View File

@ -52,7 +52,7 @@ static int trace_test_buffer(struct trace_array *tr, unsigned long *count)
int cpu, ret = 0;
/* Don't allow flipping of max traces now */
raw_local_irq_save(flags);
local_irq_save(flags);
__raw_spin_lock(&ftrace_max_lock);
cnt = ring_buffer_entries(tr->buffer);
@ -63,7 +63,7 @@ static int trace_test_buffer(struct trace_array *tr, unsigned long *count)
break;
}
__raw_spin_unlock(&ftrace_max_lock);
raw_local_irq_restore(flags);
local_irq_restore(flags);
if (count)
*count = cnt;
@ -71,6 +71,11 @@ static int trace_test_buffer(struct trace_array *tr, unsigned long *count)
return ret;
}
static inline void warn_failed_init_tracer(struct tracer *trace, int init_ret)
{
printk(KERN_WARNING "Failed to init %s tracer, init returned %d\n",
trace->name, init_ret);
}
#ifdef CONFIG_FUNCTION_TRACER
#ifdef CONFIG_DYNAMIC_FTRACE
@ -111,7 +116,11 @@ int trace_selftest_startup_dynamic_tracing(struct tracer *trace,
ftrace_set_filter(func_name, strlen(func_name), 1);
/* enable tracing */
trace->init(tr);
ret = trace->init(tr);
if (ret) {
warn_failed_init_tracer(trace, ret);
goto out;
}
/* Sleep for a 1/10 of a second */
msleep(100);
@ -181,7 +190,12 @@ trace_selftest_startup_function(struct tracer *trace, struct trace_array *tr)
ftrace_enabled = 1;
tracer_enabled = 1;
trace->init(tr);
ret = trace->init(tr);
if (ret) {
warn_failed_init_tracer(trace, ret);
goto out;
}
/* Sleep for a 1/10 of a second */
msleep(100);
/* stop the tracing. */
@ -223,7 +237,12 @@ trace_selftest_startup_irqsoff(struct tracer *trace, struct trace_array *tr)
int ret;
/* start the tracing */
trace->init(tr);
ret = trace->init(tr);
if (ret) {
warn_failed_init_tracer(trace, ret);
return ret;
}
/* reset the max latency */
tracing_max_latency = 0;
/* disable interrupts for a bit */
@ -272,7 +291,12 @@ trace_selftest_startup_preemptoff(struct tracer *trace, struct trace_array *tr)
}
/* start the tracing */
trace->init(tr);
ret = trace->init(tr);
if (ret) {
warn_failed_init_tracer(trace, ret);
return ret;
}
/* reset the max latency */
tracing_max_latency = 0;
/* disable preemption for a bit */
@ -321,7 +345,11 @@ trace_selftest_startup_preemptirqsoff(struct tracer *trace, struct trace_array *
}
/* start the tracing */
trace->init(tr);
ret = trace->init(tr);
if (ret) {
warn_failed_init_tracer(trace, ret);
goto out;
}
/* reset the max latency */
tracing_max_latency = 0;
@ -449,7 +477,12 @@ trace_selftest_startup_wakeup(struct tracer *trace, struct trace_array *tr)
wait_for_completion(&isrt);
/* start the tracing */
trace->init(tr);
ret = trace->init(tr);
if (ret) {
warn_failed_init_tracer(trace, ret);
return ret;
}
/* reset the max latency */
tracing_max_latency = 0;
@ -505,7 +538,12 @@ trace_selftest_startup_sched_switch(struct tracer *trace, struct trace_array *tr
int ret;
/* start the tracing */
trace->init(tr);
ret = trace->init(tr);
if (ret) {
warn_failed_init_tracer(trace, ret);
return ret;
}
/* Sleep for a 1/10 of a second */
msleep(100);
/* stop the tracing. */
@ -532,7 +570,12 @@ trace_selftest_startup_sysprof(struct tracer *trace, struct trace_array *tr)
int ret;
/* start the tracing */
trace->init(tr);
ret = trace->init(tr);
if (ret) {
warn_failed_init_tracer(trace, ret);
return 0;
}
/* Sleep for a 1/10 of a second */
msleep(100);
/* stop the tracing. */
@ -554,7 +597,12 @@ trace_selftest_startup_branch(struct tracer *trace, struct trace_array *tr)
int ret;
/* start the tracing */
trace->init(tr);
ret = trace->init(tr);
if (ret) {
warn_failed_init_tracer(trace, ret);
return ret;
}
/* Sleep for a 1/10 of a second */
msleep(100);
/* stop the tracing. */

3
kernel/trace/trace_sysprof.c
View File

@ -261,11 +261,12 @@ static void stop_stack_trace(struct trace_array *tr)
mutex_unlock(&sample_timer_lock);
}
static void stack_trace_init(struct trace_array *tr)
static int stack_trace_init(struct trace_array *tr)
{
sysprof_trace = tr;
start_stack_trace(tr);
return 0;
}
static void stack_trace_reset(struct trace_array *tr)

34
kernel/tracepoint.c
View File

@ -262,6 +262,7 @@ static void set_tracepoint(struct tracepoint_entry **entry,
static void disable_tracepoint(struct tracepoint *elem)
{
elem->state = 0;
rcu_assign_pointer(elem->funcs, NULL);
}
/**
@ -540,3 +541,36 @@ void tracepoint_iter_reset(struct tracepoint_iter *iter)
iter->tracepoint = NULL;
}
EXPORT_SYMBOL_GPL(tracepoint_iter_reset);
#ifdef CONFIG_MODULES
int tracepoint_module_notify(struct notifier_block *self,
unsigned long val, void *data)
{
struct module *mod = data;
switch (val) {
case MODULE_STATE_COMING:
tracepoint_update_probe_range(mod->tracepoints,
mod->tracepoints + mod->num_tracepoints);
break;
case MODULE_STATE_GOING:
tracepoint_update_probe_range(mod->tracepoints,
mod->tracepoints + mod->num_tracepoints);
break;
}
return 0;
}
struct notifier_block tracepoint_module_nb = {
.notifier_call = tracepoint_module_notify,
.priority = 0,
};
static int init_tracepoints(void)
{
return register_module_notifier(&tracepoint_module_nb);
}
__initcall(init_tracepoints);
#endif /* CONFIG_MODULES */

4
samples/tracepoints/tp-samples-trace.h
View File

@ -4,10 +4,10 @@
#include <linux/proc_fs.h> /* for struct inode and struct file */
#include <linux/tracepoint.h>
DEFINE_TRACE(subsys_event,
DECLARE_TRACE(subsys_event,
TPPROTO(struct inode *inode, struct file *file),
TPARGS(inode, file));
DEFINE_TRACE(subsys_eventb,
DECLARE_TRACE(subsys_eventb,
TPPROTO(void),
TPARGS());
#endif

1
samples/tracepoints/tracepoint-probe-sample.c
View File

@ -46,6 +46,7 @@ void __exit tp_sample_trace_exit(void)
{
unregister_trace_subsys_eventb(probe_subsys_eventb);
unregister_trace_subsys_event(probe_subsys_event);
tracepoint_synchronize_unregister();
}
module_exit(tp_sample_trace_exit);

1
samples/tracepoints/tracepoint-probe-sample2.c
View File

@ -33,6 +33,7 @@ module_init(tp_sample_trace_init);
void __exit tp_sample_trace_exit(void)
{
unregister_trace_subsys_event(probe_subsys_event);
tracepoint_synchronize_unregister();
}
module_exit(tp_sample_trace_exit);

3
samples/tracepoints/tracepoint-sample.c
View File

@ -13,6 +13,9 @@
#include <linux/proc_fs.h>
#include "tp-samples-trace.h"
DEFINE_TRACE(subsys_event);
DEFINE_TRACE(subsys_eventb);
struct proc_dir_entry *pentry_example;
static int my_open(struct inode *inode, struct file *file)