Current File : //usr/share/systemtap/runtime/linux/print.c
/* -*- linux-c -*-
* Print Functions
* Copyright (C) 2007-2018 Red Hat Inc.
*
* This file is part of systemtap, and is free software. You can
* redistribute it and/or modify it under the terms of the GNU General
* Public License (GPL); either version 2, or (at your option) any
* later version.
*/
#ifndef _STAPLINUX_PRINT_C_
#define _STAPLINUX_PRINT_C_
#include "stp_string.h"
#include "print.h"
#include "transport/transport.c"
#include "vsprintf.c"
/** @file print.c
* Printing Functions.
*/
/** @addtogroup print Print Functions
* The print buffer is for collecting output to send to the user daemon.
* This is a per-cpu static buffer. The buffer is sent when
* _stp_print_flush() is called.
*
* The reason to do this is to allow multiple small prints to be combined then
* timestamped and sent together to staprun. This is more efficient than sending
* numerous small packets.
*
* This function is called automatically when the print buffer is full.
* It MUST also be called at the end of every probe that prints something.
* @{
*/
typedef struct __stp_pbuf {
uint32_t len; /* bytes used in the buffer */
char buf[STP_BUFFER_SIZE];
} _stp_pbuf;
static void *Stp_pbuf = NULL;
/** private buffer for _stp_vlog() */
#ifndef STP_LOG_BUF_LEN
#define STP_LOG_BUF_LEN 256
#endif
typedef char _stp_lbuf[STP_LOG_BUF_LEN];
static void *Stp_lbuf = NULL;
/* create percpu print and io buffers */
static int _stp_print_init (void)
{
Stp_pbuf = _stp_alloc_percpu(sizeof(_stp_pbuf));
if (unlikely(Stp_pbuf == 0))
return -1;
/* now initialize IO buffer used in io.c */
Stp_lbuf = _stp_alloc_percpu(sizeof(_stp_lbuf));
if (unlikely(Stp_lbuf == 0)) {
_stp_free_percpu(Stp_pbuf);
return -1;
}
return 0;
}
static void _stp_print_cleanup (void)
{
if (Stp_pbuf)
_stp_free_percpu(Stp_pbuf);
if (Stp_lbuf)
_stp_free_percpu(Stp_lbuf);
}
#include "print_flush.c"
static inline void _stp_print_flush(void)
{
stp_print_flush(per_cpu_ptr(Stp_pbuf, smp_processor_id()));
}
#ifndef STP_MAXBINARYARGS
#define STP_MAXBINARYARGS 127
#endif
/** Reserves space in the output buffer for direct I/O.
*/
static void * _stp_reserve_bytes (int numbytes)
{
_stp_pbuf *pb = per_cpu_ptr(Stp_pbuf, smp_processor_id());
int size = STP_BUFFER_SIZE - pb->len;
void * ret;
if (unlikely(numbytes == 0 || numbytes > STP_BUFFER_SIZE))
return NULL;
if (unlikely(numbytes > size))
_stp_print_flush();
ret = pb->buf + pb->len;
pb->len += numbytes;
return ret;
}
static void _stp_unreserve_bytes (int numbytes)
{
_stp_pbuf *pb = per_cpu_ptr(Stp_pbuf, smp_processor_id());
if (unlikely(numbytes == 0 || numbytes > pb->len))
return;
pb->len -= numbytes;
}
/** Write 64-bit args directly into the output stream.
* This function takes a variable number of 64-bit arguments
* and writes them directly into the output stream. Marginally faster
* than doing the same in _stp_vsnprintf().
* @sa _stp_vsnprintf()
*/
static void _stp_print_binary (int num, ...)
{
va_list vargs;
int i;
int64_t *args;
if (unlikely(num > STP_MAXBINARYARGS))
num = STP_MAXBINARYARGS;
args = _stp_reserve_bytes(num * sizeof(int64_t));
if (likely(args != NULL)) {
va_start(vargs, num);
for (i = 0; i < num; i++) {
args[i] = va_arg(vargs, int64_t);
}
va_end(vargs);
}
}
/** Print into the print buffer.
* Like C printf.
*
* @sa _stp_print_flush()
*/
static void _stp_printf (const char *fmt, ...)
{
va_list args;
va_start(args, fmt);
_stp_vsnprintf(NULL, 0, fmt, args);
va_end(args);
}
/** Write a string into the print buffer.
* @param str A C string (char *)
*/
static void _stp_print (const char *str)
{
_stp_pbuf *pb = per_cpu_ptr(Stp_pbuf, smp_processor_id());
char *end = pb->buf + STP_BUFFER_SIZE;
char *ptr = pb->buf + pb->len;
char *instr = (char *)str;
while (ptr < end && *instr)
*ptr++ = *instr++;
/* Did loop terminate due to lack of buffer space? */
if (unlikely(*instr)) {
/* Don't break strings across subbufs. */
/* Restart after flushing. */
_stp_print_flush();
end = pb->buf + STP_BUFFER_SIZE;
ptr = pb->buf + pb->len;
instr = (char *)str;
while (ptr < end && *instr)
*ptr++ = *instr++;
}
pb->len = ptr - pb->buf;
}
static void _stp_print_char (const char c)
{
_stp_pbuf *pb = per_cpu_ptr(Stp_pbuf, smp_processor_id());
int size = STP_BUFFER_SIZE - pb->len;
if (unlikely(1 >= size))
_stp_print_flush();
pb->buf[pb->len] = c;
pb->len ++;
}
static void _stp_print_kernel_info(char *sname, char *vstr, int ctx, int num_probes)
{
printk(KERN_DEBUG
"%s (%s): systemtap: %s, base: %p"
", memory: %ludata/%lutext/%uctx/%unet/%ualloc kb"
", probes: %d"
#if ! STP_PRIVILEGE_CONTAINS (STP_PRIVILEGE, STP_PR_STAPDEV)
", unpriv-uid: %d"
#endif
"\n",
THIS_MODULE->name,
sname, /* name of source file */
vstr, /* stap version */
#ifdef STAPCONF_MODULE_LAYOUT
THIS_MODULE->core_layout.base,
(unsigned long) (THIS_MODULE->core_layout.size - THIS_MODULE->core_layout.text_size)/1024,
(unsigned long) (THIS_MODULE->core_layout.text_size)/1024,
#else
#ifndef STAPCONF_GRSECURITY
THIS_MODULE->module_core,
(unsigned long) (THIS_MODULE->core_size - THIS_MODULE->core_text_size)/1024,
(unsigned long) (THIS_MODULE->core_text_size)/1024,
#else
THIS_MODULE->module_core_rx,
(unsigned long) (THIS_MODULE->core_size_rw - THIS_MODULE->core_size_rx)/1024,
(unsigned long) (THIS_MODULE->core_size_rx)/1024,
#endif
#endif
ctx/1024,
_stp_allocated_net_memory/1024,
(_stp_allocated_memory - _stp_allocated_net_memory - ctx)/1024,
/* (un-double-counting net/ctx because they're also stp_alloc'd) */
num_probes
#if ! STP_PRIVILEGE_CONTAINS (STP_PRIVILEGE, STP_PR_STAPDEV)
, _stp_uid
#endif
);
}
/** @} */
#endif /* _STAPLINUX_PRINT_C_ */
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