Systemtap Userspace probing - 4
背景
接上一篇BLOG
http://blog.163.com/digoal@126/blog/static/163877040201383042846295/
本文讲一下userspace 探针的最后一点内容, 静态userspace探针.
Static userspace probing
You can probe symbolic static instrumentation compiled into programs and shared libraries with the following syntax:
process("PATH").mark("LABEL")
The .mark variant is called from a static probe defined in the application by STAP_PROBE1(handle,LABEL,arg1). STAP_PROBE1 is defined in the sdt.h file. The parameters are:
Parameter Definition
handle the application handle
LABEL corresponds to the .mark argument
arg1 the argument
Use STAP_PROBE1 for probes with one argument. Use STAP_PROBE2 for probes with 2 arguments, and so on. The arguments of the probe are available in the context variables $arg1, $arg2, and so on.
As an alternative to the STAP_PROBE macros, you can use the dtrace script to create custom macros. The sdt.h file also provides dtrace compatible markers through DTRACE_PROBE and an associated python dtrace script. You can use these in builds based on dtrace that need dtrace -h or -G functionality.
使用这些宏添加静态用户空间探针, 支持无参数, 或者1-12个参数的宏. 语法如下 :
STAP_PROBE[1-12](handle,LABEL[,arg1-12])
DTRACE_PROBE[1-12](handle,LABEL[,arg1-12])
静态userspace探针的用法
probe process("PATH").mark("LABEL")
例如在PostgreSQL定义的某静态探针, 使用的是DTRACE模式定义, 在sdt.h中有DTRACE的兼容模式, 所以也可以用.
src/backend/utils/probes.h
/* Generated by the Systemtap dtrace wrapper */
#define _SDT_HAS_SEMAPHORES 1
#define STAP_HAS_SEMAPHORES 1 /* deprecated */
#include <sys/sdt.h>
/* TRACE_POSTGRESQL_TRANSACTION_START ( unsigned int) */
#if defined STAP_SDT_V1
#define TRACE_POSTGRESQL_TRANSACTION_START_ENABLED() __builtin_expect (transaction__start_semaphore, 0)
#define postgresql_transaction__start_semaphore transaction__start_semaphore
#else
#define TRACE_POSTGRESQL_TRANSACTION_START_ENABLED() __builtin_expect (postgresql_transaction__start_semaphore, 0)
#endif
__extension__ extern unsigned short postgresql_transaction__start_semaphore __attribute__ ((unused)) __attribute__ ((section (".prob
es")));
#define TRACE_POSTGRESQL_TRANSACTION_START(arg1) \
DTRACE_PROBE1(postgresql,transaction__start,arg1)
PG中使用的是dtrace宏定义,
DTRACE_PROBE1(postgresql,transaction__start,arg1)
DTRACE_PROBE1在sdt.h中可以找到.
#define DTRACE_PROBE1(provider,probe,parm1) \
STAP_PROBE1(provider,probe,parm1)
如果要使用以上PostgreSQL中定义的这个静态探针, 如下 :
probe process("/opt/pgsql/bin/postgres").mark("transaction__start")
举例如下 :
首先, 前面举例用到的在PostgreSQL中定义的静态用户空间探针transaction__start对应的宏TRACE_POSTGRESQL_TRANSACTION_START在代码中被植入的位置如下,
src/backend/access/transam/xact.c
/*
* StartTransaction
*/
static void
StartTransaction(void)
{
TransactionState s;
VirtualTransactionId vxid;
... 略
/*
* Advertise it in the proc array. We assume assignment of
* LocalTransactionID is atomic, and the backendId should be set already.
*/
Assert(MyProc->backendId == vxid.backendId);
MyProc->lxid = vxid.localTransactionId;
TRACE_POSTGRESQL_TRANSACTION_START(vxid.localTransactionId);
所以对应的参数arg1是vxid.localTransactionId
下面我们来做一个测试 :
user_string这没有, 因为$arg1不是一个字符串, 可以不用管它.
[root@db-172-16-3-39 ~]# stap -e 'global cnt; probe process("/home/pg94/pgsql9.4devel/bin/postgres").mark("transaction__start") { cnt<<<1; printf("%d, %s, %s, %s\n", pid(), pp(), $$vars, user_string($arg1)) }'
测试过程中做几条查询
begin;
end;
begin;
end;
begin;
end;
stap输出如下 :
4349, process("/home/pg94/pgsql9.4devel/bin/postgres").statement(0x4a4caa), $arg1=0x10, <unknown>
4349, process("/home/pg94/pgsql9.4devel/bin/postgres").statement(0x4a4caa), $arg1=0x11, <unknown>
4349, process("/home/pg94/pgsql9.4devel/bin/postgres").statement(0x4a4caa), $arg1=0x12, <unknown>
观察久一点的话, 可能还有其他进程的输出.
[root@db-172-16-3-39 ~]# stap -e 'global cnt; probe process("/home/pg94/pgsql9.4devel/bin/postgres").mark("transaction__start") { cnt<<<1; printf("%d, %s, %s, %s\n", pid(), pp(), $$vars, user_string($arg1)) }'
4349, process("/home/pg94/pgsql9.4devel/bin/postgres").statement(0x4a4caa), $arg1=0x10, <unknown>
4349, process("/home/pg94/pgsql9.4devel/bin/postgres").statement(0x4a4caa), $arg1=0x11, <unknown>
4349, process("/home/pg94/pgsql9.4devel/bin/postgres").statement(0x4a4caa), $arg1=0x12, <unknown>
4212, process("/home/pg94/pgsql9.4devel/bin/postgres").statement(0x4a4caa), $arg1=0xc, <unknown>
4991, process("/home/pg94/pgsql9.4devel/bin/postgres").statement(0x4a4caa), $arg1=0x13, <unknown>
4991, process("/home/pg94/pgsql9.4devel/bin/postgres").statement(0x4a4caa), $arg1=0x14, <unknown>
4993, process("/home/pg94/pgsql9.4devel/bin/postgres").statement(0x4a4caa), $arg1=0x15, <unknown>
4993, process("/home/pg94/pgsql9.4devel/bin/postgres").statement(0x4a4caa), $arg1=0x16, <unknown>
4993, process("/home/pg94/pgsql9.4devel/bin/postgres").statement(0x4a4caa), $arg1=0x17, <unknown>
4993, process("/home/pg94/pgsql9.4devel/bin/postgres").statement(0x4a4caa), $arg1=0x18, <unknown>
4993, process("/home/pg94/pgsql9.4devel/bin/postgres").statement(0x4a4caa), $arg1=0x19, <unknown>
4212, process("/home/pg94/pgsql9.4devel/bin/postgres").statement(0x4a4caa), $arg1=0xd, <unknown>
4998, process("/home/pg94/pgsql9.4devel/bin/postgres").statement(0x4a4caa), $arg1=0xf, <unknown>
4998, process("/home/pg94/pgsql9.4devel/bin/postgres").statement(0x4a4caa), $arg1=0x10, <unknown>
4993, process("/home/pg94/pgsql9.4devel/bin/postgres").statement(0x4a4caa), $arg1=0x1a, <unknown>
4212, process("/home/pg94/pgsql9.4devel/bin/postgres").statement(0x4a4caa), $arg1=0xe, <unknown>
5012, process("/home/pg94/pgsql9.4devel/bin/postgres").statement(0x4a4caa), $arg1=0x11, <unknown>
5012, process("/home/pg94/pgsql9.4devel/bin/postgres").statement(0x4a4caa), $arg1=0x12, <unknown>
参考
1. http://blog.163.com/digoal@126/blog/static/163877040201382941342901/
2. http://blog.163.com/digoal@126/blog/static/16387704020138301545039/
3. http://blog.163.com/digoal@126/blog/static/163877040201383042846295/
4. src/backend/utils/probes.h
5. /usr/include/sys/sdt.h
/* <sys/sdt.h> - Systemtap static probe definition macros.
Copyright (C) 2010-2011 Red Hat Inc.
This file is part of systemtap, and is free software in the public domain.
*/
#ifndef _SYS_SDT_H
#define _SYS_SDT_H 1
#ifdef __ASSEMBLER__
# define _SDT_PROBE(provider, name, n, arglist) \
_SDT_ASM_BODY(provider, name, _SDT_ASM_STRING_1, (_SDT_DEPAREN_##n arglist)) \
_SDT_ASM_BASE
# define _SDT_ASM_1(x) x;
# define _SDT_ASM_2(a, b) a,b;
# define _SDT_ASM_3(a, b, c) a,b,c;
# define _SDT_ASM_5(a, b, c, d, e) a,b,c,d,e;
# define _SDT_ASM_STRING_1(x) .asciz #x;
# define _SDT_DEPAREN_0() /* empty */
# define _SDT_DEPAREN_1(a) a
# define _SDT_DEPAREN_2(a,b) a b
# define _SDT_DEPAREN_3(a,b,c) a b c
# define _SDT_DEPAREN_4(a,b,c,d) a b c d
# define _SDT_DEPAREN_5(a,b,c,d,e) a b c d e
# define _SDT_DEPAREN_6(a,b,c,d,e,f) a b c d e f
# define _SDT_DEPAREN_7(a,b,c,d,e,f,g) a b c d e f g
# define _SDT_DEPAREN_8(a,b,c,d,e,f,g,h) a b c d e f g h
# define _SDT_DEPAREN_9(a,b,c,d,e,f,g,h,i) a b c d e f g h i
# define _SDT_DEPAREN_10(a,b,c,d,e,f,g,h,i,j) a b c d e f g h i j
# define _SDT_DEPAREN_11(a,b,c,d,e,f,g,h,i,j,k) a b c d e f g h i j k
# define _SDT_DEPAREN_12(a,b,c,d,e,f,g,h,i,j,k,l) a b c d e f g h i j k l
#else
# include <stdint.h>
# define _SDT_PROBE(provider, name, n, arglist) \
do { \
__asm__ __volatile__ (_SDT_ASM_BODY(provider, name, _SDT_ASM_ARGS, (n)) \
:: _SDT_ASM_OPERANDS_##n arglist); \
__asm__ __volatile__ (_SDT_ASM_BASE); \
} while (0)
# define _SDT_S(x) #x
# define _SDT_ASM_1(x) _SDT_S(x) "\n"
# define _SDT_ASM_2(a, b) _SDT_S(a) "," _SDT_S(b) "\n"
# define _SDT_ASM_3(a, b, c) _SDT_S(a) "," _SDT_S(b) "," \
_SDT_S(c) "\n"
# define _SDT_ASM_5(a, b, c, d, e) _SDT_S(a) "," _SDT_S(b) "," \
_SDT_S(c) "," _SDT_S(d) "," \
_SDT_S(e) "\n"
# define _SDT_ASM_ARGS(n) _SDT_ASM_STRING(_SDT_ASM_TEMPLATE_##n)
# define _SDT_ASM_STRING_1(x) _SDT_ASM_1(.asciz #x)
# define _SDT_ARGFMT(no) %n[_SDT_S##no]@_SDT_ARGTMPL(_SDT_A##no)
# ifndef STAP_SDT_ARG_CONSTRAINT
# define STAP_SDT_ARG_CONSTRAINT nor
# endif
# define _SDT_STRINGIFY(x) #x
# define _SDT_ARG_CONSTRAINT_STRING(x) _SDT_STRINGIFY(x)
# define _SDT_ARG(n, x) \
[_SDT_S##n] "n" ((_SDT_ARGSIGNED (x) ? 1 : -1) * (int) _SDT_ARGSIZE (x)), \
[_SDT_A##n] _SDT_ARG_CONSTRAINT_STRING (STAP_SDT_ARG_CONSTRAINT) (_SDT_ARGVAL (x))
#endif
#define _SDT_ASM_STRING(x) _SDT_ASM_STRING_1(x)
#define _SDT_ARGARRAY(x) (__builtin_classify_type (x) == 14 \
|| __builtin_classify_type (x) == 5)
#ifdef __cplusplus
# define _SDT_ARGSIGNED(x) (!_SDT_ARGARRAY (x) \
&& __sdt_type<__typeof (x)>::__sdt_signed)
# define _SDT_ARGSIZE(x) (_SDT_ARGARRAY (x) \
? sizeof (void *) : sizeof (x))
# define _SDT_ARGVAL(x) (x)
# include <cstddef>
template<typename __sdt_T>
struct __sdt_type
{
static const bool __sdt_signed = false;
};
#define __SDT_ALWAYS_SIGNED(T) \
template<> struct __sdt_type<T> { static const bool __sdt_signed = true; };
#define __SDT_COND_SIGNED(T) \
template<> struct __sdt_type<T> { static const bool __sdt_signed = ((T)(-1) < 1); };
__SDT_ALWAYS_SIGNED(signed char)
__SDT_ALWAYS_SIGNED(short)
__SDT_ALWAYS_SIGNED(int)
__SDT_ALWAYS_SIGNED(long)
__SDT_ALWAYS_SIGNED(long long)
__SDT_ALWAYS_SIGNED(volatile signed char)
__SDT_ALWAYS_SIGNED(volatile short)
__SDT_ALWAYS_SIGNED(volatile int)
__SDT_ALWAYS_SIGNED(volatile long)
__SDT_ALWAYS_SIGNED(volatile long long)
__SDT_ALWAYS_SIGNED(const signed char)
__SDT_ALWAYS_SIGNED(const short)
__SDT_ALWAYS_SIGNED(const int)
__SDT_ALWAYS_SIGNED(const long)
__SDT_ALWAYS_SIGNED(const long long)
__SDT_ALWAYS_SIGNED(const volatile signed char)
__SDT_ALWAYS_SIGNED(const volatile short)
__SDT_ALWAYS_SIGNED(const volatile int)
__SDT_ALWAYS_SIGNED(const volatile long)
__SDT_ALWAYS_SIGNED(const volatile long long)
__SDT_COND_SIGNED(char)
__SDT_COND_SIGNED(wchar_t)
__SDT_COND_SIGNED(volatile char)
__SDT_COND_SIGNED(volatile wchar_t)
__SDT_COND_SIGNED(const char)
__SDT_COND_SIGNED(const wchar_t)
__SDT_COND_SIGNED(const volatile char)
__SDT_COND_SIGNED(const volatile wchar_t)
#if defined (__GNUC__) && (__GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 4))
/* __SDT_COND_SIGNED(char16_t) */
/* __SDT_COND_SIGNED(char32_t) */
#endif
template<typename __sdt_E>
struct __sdt_type<__sdt_E[]> : public __sdt_type<__sdt_E *> {};
template<typename __sdt_E, size_t __sdt_N>
struct __sdt_type<__sdt_E[__sdt_N]> : public __sdt_type<__sdt_E *> {};
#elif !defined(__ASSEMBLER__)
__extension__ extern unsigned long long __sdt_unsp;
# define _SDT_ARGINTTYPE(x) \
__typeof (__builtin_choose_expr (((__builtin_classify_type (x) \
+ 3) & -4) == 4, (x), 0U))
# define _SDT_ARGSIGNED(x) \
(!__extension__ \
(__builtin_constant_p ((((unsigned long long) \
(_SDT_ARGINTTYPE (x)) __sdt_unsp) \
& ((unsigned long long)1 << (sizeof (unsigned long long) \
* __CHAR_BIT__ - 1))) == 0) \
|| (_SDT_ARGINTTYPE (x)) -1 > (_SDT_ARGINTTYPE (x)) 0))
# define _SDT_ARGSIZE(x) \
(_SDT_ARGARRAY (x) ? sizeof (void *) : sizeof (x))
# define _SDT_ARGVAL(x) (x)
#endif
#if defined __powerpc__ || defined __powerpc64__
# define _SDT_ARGTMPL(id) %I[id]%[id]
#else
# define _SDT_ARGTMPL(id) %[id]
#endif
#ifdef __LP64__
# define _SDT_ASM_ADDR .8byte
#else
# define _SDT_ASM_ADDR .4byte
#endif
/* The ia64 and s390 nop instructions take an argument. */
#if defined(__ia64__) || defined(__s390__) || defined(__s390x__)
#define _SDT_NOP nop 0
#else
#define _SDT_NOP nop
#endif
#define _SDT_NOTE_NAME "stapsdt"
#define _SDT_NOTE_TYPE 3
/* If the assembler supports the necessary feature, then we can play
nice with code in COMDAT sections, which comes up in C++ code.
Without that assembler support, some combinations of probe placements
in certain kinds of C++ code may produce link-time errors. */
#include "sdt-config.h"
#if _SDT_ASM_SECTION_AUTOGROUP_SUPPORT
# define _SDT_ASM_AUTOGROUP "?"
#else
# define _SDT_ASM_AUTOGROUP ""
#endif
#define _SDT_ASM_BODY(provider, name, pack_args, args) \
_SDT_ASM_1(990: _SDT_NOP) \
_SDT_ASM_3( .pushsection .note.stapsdt,_SDT_ASM_AUTOGROUP,"note") \
_SDT_ASM_1( .balign 4) \
_SDT_ASM_3( .4byte 992f-991f, 994f-993f, _SDT_NOTE_TYPE) \
_SDT_ASM_1(991: .asciz _SDT_NOTE_NAME) \
_SDT_ASM_1(992: .balign 4) \
_SDT_ASM_1(993: _SDT_ASM_ADDR 990b) \
_SDT_ASM_1( _SDT_ASM_ADDR _.stapsdt.base) \
_SDT_SEMAPHORE(provider,name) \
_SDT_ASM_STRING(provider) \
_SDT_ASM_STRING(name) \
pack_args args \
_SDT_ASM_1(994: .balign 4) \
_SDT_ASM_1( .popsection)
#define _SDT_ASM_BASE \
_SDT_ASM_1(.ifndef _.stapsdt.base) \
_SDT_ASM_5( .pushsection .stapsdt.base,"aG","progbits", \
.stapsdt.base,comdat) \
_SDT_ASM_1( .weak _.stapsdt.base) \
_SDT_ASM_1( .hidden _.stapsdt.base) \
_SDT_ASM_1( _.stapsdt.base: .space 1) \
_SDT_ASM_2( .size _.stapsdt.base, 1) \
_SDT_ASM_1( .popsection) \
_SDT_ASM_1(.endif)
#if defined _SDT_HAS_SEMAPHORES
#define _SDT_SEMAPHORE(p,n) _SDT_ASM_1( _SDT_ASM_ADDR p##_##n##_semaphore)
#else
#define _SDT_SEMAPHORE(p,n) _SDT_ASM_1( _SDT_ASM_ADDR 0)
#endif
#define _SDT_ASM_TEMPLATE_0 /* no arguments */
#define _SDT_ASM_TEMPLATE_1 _SDT_ARGFMT(1)
#define _SDT_ASM_TEMPLATE_2 _SDT_ASM_TEMPLATE_1 _SDT_ARGFMT(2)
#define _SDT_ASM_TEMPLATE_3 _SDT_ASM_TEMPLATE_2 _SDT_ARGFMT(3)
#define _SDT_ASM_TEMPLATE_4 _SDT_ASM_TEMPLATE_3 _SDT_ARGFMT(4)
#define _SDT_ASM_TEMPLATE_5 _SDT_ASM_TEMPLATE_4 _SDT_ARGFMT(5)
#define _SDT_ASM_TEMPLATE_6 _SDT_ASM_TEMPLATE_5 _SDT_ARGFMT(6)
#define _SDT_ASM_TEMPLATE_7 _SDT_ASM_TEMPLATE_6 _SDT_ARGFMT(7)
#define _SDT_ASM_TEMPLATE_8 _SDT_ASM_TEMPLATE_7 _SDT_ARGFMT(8)
#define _SDT_ASM_TEMPLATE_9 _SDT_ASM_TEMPLATE_8 _SDT_ARGFMT(9)
#define _SDT_ASM_TEMPLATE_10 _SDT_ASM_TEMPLATE_9 _SDT_ARGFMT(10)
#define _SDT_ASM_TEMPLATE_11 _SDT_ASM_TEMPLATE_10 _SDT_ARGFMT(11)
#define _SDT_ASM_TEMPLATE_12 _SDT_ASM_TEMPLATE_11 _SDT_ARGFMT(12)
#define _SDT_ASM_OPERANDS_0() [__sdt_dummy] "g" (0)
#define _SDT_ASM_OPERANDS_1(arg1) _SDT_ARG(1, arg1)
#define _SDT_ASM_OPERANDS_2(arg1, arg2) \
_SDT_ASM_OPERANDS_1(arg1), _SDT_ARG(2, arg2)
#define _SDT_ASM_OPERANDS_3(arg1, arg2, arg3) \
_SDT_ASM_OPERANDS_2(arg1, arg2), _SDT_ARG(3, arg3)
#define _SDT_ASM_OPERANDS_4(arg1, arg2, arg3, arg4) \
_SDT_ASM_OPERANDS_3(arg1, arg2, arg3), _SDT_ARG(4, arg4)
#define _SDT_ASM_OPERANDS_5(arg1, arg2, arg3, arg4, arg5) \
_SDT_ASM_OPERANDS_4(arg1, arg2, arg3, arg4), _SDT_ARG(5, arg5)
#define _SDT_ASM_OPERANDS_6(arg1, arg2, arg3, arg4, arg5, arg6) \
_SDT_ASM_OPERANDS_5(arg1, arg2, arg3, arg4, arg5), _SDT_ARG(6, arg6)
#define _SDT_ASM_OPERANDS_7(arg1, arg2, arg3, arg4, arg5, arg6, arg7) \
_SDT_ASM_OPERANDS_6(arg1, arg2, arg3, arg4, arg5, arg6), _SDT_ARG(7, arg7)
#define _SDT_ASM_OPERANDS_8(arg1, arg2, arg3, arg4, arg5, arg6, arg7, arg8) \
_SDT_ASM_OPERANDS_7(arg1, arg2, arg3, arg4, arg5, arg6, arg7), \
_SDT_ARG(8, arg8)
#define _SDT_ASM_OPERANDS_9(arg1,arg2,arg3,arg4,arg5,arg6,arg7,arg8,arg9) \
_SDT_ASM_OPERANDS_8(arg1, arg2, arg3, arg4, arg5, arg6, arg7, arg8), \
_SDT_ARG(9, arg9)
#define _SDT_ASM_OPERANDS_10(arg1,arg2,arg3,arg4,arg5,arg6,arg7,arg8,arg9,arg10) \
_SDT_ASM_OPERANDS_9(arg1, arg2, arg3, arg4, arg5, arg6, arg7, arg8, arg9), \
_SDT_ARG(10, arg10)
#define _SDT_ASM_OPERANDS_11(arg1,arg2,arg3,arg4,arg5,arg6,arg7,arg8,arg9,arg10,arg11) \
_SDT_ASM_OPERANDS_10(arg1, arg2, arg3, arg4, arg5, arg6, arg7, arg8, arg9, arg10), \
_SDT_ARG(11, arg11)
#define _SDT_ASM_OPERANDS_12(arg1,arg2,arg3,arg4,arg5,arg6,arg7,arg8,arg9,arg10,arg11,arg12) \
_SDT_ASM_OPERANDS_11(arg1, arg2, arg3, arg4, arg5, arg6, arg7, arg8, arg9, arg10, arg11), \
_SDT_ARG(12, arg12)
/* These macros can be used in C, C++, or assembly code.
In assembly code the arguments should use normal assembly operand syntax. */
#define STAP_PROBE(provider, name) \
_SDT_PROBE(provider, name, 0, ())
#define STAP_PROBE1(provider, name, arg1) \
_SDT_PROBE(provider, name, 1, (arg1))
#define STAP_PROBE2(provider, name, arg1, arg2) \
_SDT_PROBE(provider, name, 2, (arg1, arg2))
#define STAP_PROBE3(provider, name, arg1, arg2, arg3) \
_SDT_PROBE(provider, name, 3, (arg1, arg2, arg3))
#define STAP_PROBE4(provider, name, arg1, arg2, arg3, arg4) \
_SDT_PROBE(provider, name, 4, (arg1, arg2, arg3, arg4))
#define STAP_PROBE5(provider, name, arg1, arg2, arg3, arg4, arg5) \
_SDT_PROBE(provider, name, 5, (arg1, arg2, arg3, arg4, arg5))
#define STAP_PROBE6(provider, name, arg1, arg2, arg3, arg4, arg5, arg6) \
_SDT_PROBE(provider, name, 6, (arg1, arg2, arg3, arg4, arg5, arg6))
#define STAP_PROBE7(provider, name, arg1, arg2, arg3, arg4, arg5, arg6, arg7) \
_SDT_PROBE(provider, name, 7, (arg1, arg2, arg3, arg4, arg5, arg6, arg7))
#define STAP_PROBE8(provider,name,arg1,arg2,arg3,arg4,arg5,arg6,arg7,arg8) \
_SDT_PROBE(provider, name, 8, (arg1,arg2,arg3,arg4,arg5,arg6,arg7,arg8))
#define STAP_PROBE9(provider,name,arg1,arg2,arg3,arg4,arg5,arg6,arg7,arg8,arg9)\
_SDT_PROBE(provider, name, 9, (arg1,arg2,arg3,arg4,arg5,arg6,arg7,arg8,arg9))
#define STAP_PROBE10(provider,name,arg1,arg2,arg3,arg4,arg5,arg6,arg7,arg8,arg9,arg10) \
_SDT_PROBE(provider, name, 10, \
(arg1,arg2,arg3,arg4,arg5,arg6,arg7,arg8,arg9,arg10))
#define STAP_PROBE11(provider,name,arg1,arg2,arg3,arg4,arg5,arg6,arg7,arg8,arg9,arg10,arg11) \
_SDT_PROBE(provider, name, 11, \
(arg1,arg2,arg3,arg4,arg5,arg6,arg7,arg8,arg9,arg10,arg11))
#define STAP_PROBE12(provider,name,arg1,arg2,arg3,arg4,arg5,arg6,arg7,arg8,arg9,arg10,arg11,arg12) \
_SDT_PROBE(provider, name, 12, \
(arg1,arg2,arg3,arg4,arg5,arg6,arg7,arg8,arg9,arg10,arg11,arg12))
/* This STAP_PROBEV macro can be used in variadic scenarios, where the
number of probe arguments is not known until compile time. Since
variadic macro support may vary with compiler options, you must
pre-#define SDT_USE_VARIADIC to enable this type of probe.
The trick to count __VA_ARGS__ was inspired by this post by
Laurent Deniau <laurent.deniau@cern.ch>:
http://groups.google.com/group/comp.std.c/msg/346fc464319b1ee5
Note that our _SDT_NARG is called with an extra 0 arg that's not
counted, so we don't have to worry about the behavior of macros
called without any arguments. */
#ifdef SDT_USE_VARIADIC
#define _SDT_NARG(...) __SDT_NARG(__VA_ARGS__, 12,11,10,9,8,7,6,5,4,3,2,1,0)
#define __SDT_NARG(_0,_1,_2,_3,_4,_5,_6,_7,_8,_9,_10,_11,_12, N, ...) N
#define _SDT_PROBE_N(provider, name, N, ...) \
_SDT_PROBE(provider, name, N, (__VA_ARGS__))
#define STAP_PROBEV(provider, name, ...) \
_SDT_PROBE_N(provider, name, _SDT_NARG(0, ##__VA_ARGS__), ##__VA_ARGS__)
#endif
/* These macros are for use in asm statements. You must compile
with -std=gnu99 or -std=c99 to use the STAP_PROBE_ASM macro.
The STAP_PROBE_ASM macro generates a quoted string to be used in the
template portion of the asm statement, concatenated with strings that
contain the actual assembly code around the probe site.
For example:
asm ("before\n"
STAP_PROBE_ASM(provider, fooprobe, %eax 4(%esi))
"after");
emits the assembly code for "before\nafter", with a probe in between.
The probe arguments are the %eax register, and the value of the memory
word located 4 bytes past the address in the %esi register. Note that
because this is a simple asm, not a GNU C extended asm statement, these
% characters do not need to be doubled to generate literal %reg names.
In a GNU C extended asm statement, the probe arguments can be specified
using the macro STAP_PROBE_ASM_TEMPLATE(n) for n arguments. The paired
macro STAP_PROBE_ASM_OPERANDS gives the C values of these probe arguments,
and appears in the input operand list of the asm statement. For example:
asm ("someinsn %0,%1\n" // %0 is output operand, %1 is input operand
STAP_PROBE_ASM(provider, fooprobe, STAP_PROBE_ASM_TEMPLATE(3))
"otherinsn %[namedarg]"
: "r" (outvar)
: "g" (some_value), [namedarg] "i" (1234),
STAP_PROBE_ASM_OPERANDS(3, some_value, some_ptr->field, 1234));
This is just like writing:
STAP_PROBE3(provider, fooprobe, some_value, some_ptr->field, 1234));
but the probe site is right between "someinsn" and "otherinsn".
The probe arguments in STAP_PROBE_ASM can be given as assembly
operands instead, even inside a GNU C extended asm statement.
Note that these can use operand templates like %0 or %[name],
and likewise they must write %%reg for a literal operand of %reg. */
#if __STDC_VERSION__ >= 199901L
# define STAP_PROBE_ASM(provider, name, ...) \
_SDT_ASM_BODY(provider, name, _SDT_ASM_STRING, (__VA_ARGS__)) \
_SDT_ASM_BASE
# define STAP_PROBE_ASM_OPERANDS(n, ...) _SDT_ASM_OPERANDS_##n(__VA_ARGS__)
#else
# define STAP_PROBE_ASM(provider, name, args) \
_SDT_ASM_BODY(provider, name, _SDT_ASM_STRING, (args)) \
_SDT_ASM_BASE
#endif
#define STAP_PROBE_ASM_TEMPLATE(n) _SDT_ASM_TEMPLATE_##n
/* DTrace compatible macro names. */
#define DTRACE_PROBE(provider,probe) \
STAP_PROBE(provider,probe)
#define DTRACE_PROBE1(provider,probe,parm1) \
STAP_PROBE1(provider,probe,parm1)
#define DTRACE_PROBE2(provider,probe,parm1,parm2) \
STAP_PROBE2(provider,probe,parm1,parm2)
#define DTRACE_PROBE3(provider,probe,parm1,parm2,parm3) \
STAP_PROBE3(provider,probe,parm1,parm2,parm3)
#define DTRACE_PROBE4(provider,probe,parm1,parm2,parm3,parm4) \
STAP_PROBE4(provider,probe,parm1,parm2,parm3,parm4)
#define DTRACE_PROBE5(provider,probe,parm1,parm2,parm3,parm4,parm5) \
STAP_PROBE5(provider,probe,parm1,parm2,parm3,parm4,parm5)
#define DTRACE_PROBE6(provider,probe,parm1,parm2,parm3,parm4,parm5,parm6) \
STAP_PROBE6(provider,probe,parm1,parm2,parm3,parm4,parm5,parm6)
#define DTRACE_PROBE7(provider,probe,parm1,parm2,parm3,parm4,parm5,parm6,parm7) \
STAP_PROBE7(provider,probe,parm1,parm2,parm3,parm4,parm5,parm6,parm7)
#define DTRACE_PROBE8(provider,probe,parm1,parm2,parm3,parm4,parm5,parm6,parm7,parm8) \
STAP_PROBE8(provider,probe,parm1,parm2,parm3,parm4,parm5,parm6,parm7,parm8)
#define DTRACE_PROBE9(provider,probe,parm1,parm2,parm3,parm4,parm5,parm6,parm7,parm8,parm9) \
STAP_PROBE9(provider,probe,parm1,parm2,parm3,parm4,parm5,parm6,parm7,parm8,parm9)
#define DTRACE_PROBE10(provider,probe,parm1,parm2,parm3,parm4,parm5,parm6,parm7,parm8,parm9,parm10) \
STAP_PROBE10(provider,probe,parm1,parm2,parm3,parm4,parm5,parm6,parm7,parm8,parm9,parm10)
#define DTRACE_PROBE11(provider,probe,parm1,parm2,parm3,parm4,parm5,parm6,parm7,parm8,parm9,parm10,parm11) \
STAP_PROBE11(provider,probe,parm1,parm2,parm3,parm4,parm5,parm6,parm7,parm8,parm9,parm10,parm11)
#define DTRACE_PROBE12(provider,probe,parm1,parm2,parm3,parm4,parm5,parm6,parm7,parm8,parm9,parm10,parm11,parm12) \
STAP_PROBE12(provider,probe,parm1,parm2,parm3,parm4,parm5,parm6,parm7,parm8,parm9,parm10,parm11,parm12)
#endif /* sys/sdt.h */