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/*
* Berkeley Lab Checkpoint/Restart (BLCR) for Linux is Copyright (c)
* 2008, The Regents of the University of California, through Lawrence
* Berkeley National Laboratory (subject to receipt of any required
* approvals from the U.S. Dept. of Energy). All rights reserved.
*
* Portions may be copyrighted by others, as may be noted in specific
* copyright notices within specific files.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
* $Id: cr_ktrace.c,v 1.15 2008/12/11 06:33:39 phargrov Exp $
*
*
* Tracing and error/warning output for checkpoint/restart kernel code.
*/
#include "cr_module.h"
#include <asm/uaccess.h>
#include "cr_ktrace.h"
static char cr_trace_buf[4096];
static CR_DEFINE_SPINLOCK(cr_trace_lock);
#if CR_KERNEL_TRACING
unsigned int cr_ktrace_mask = CR_KTRACE_DEFAULT;
void
cr_print_trace(const char *file, int line, const char *func, const char * fmt, ...)
{
va_list args;
const char *p;
spin_lock(&cr_trace_lock);
va_start(args, fmt);
vsprintf(cr_trace_buf, fmt, args);
va_end(args);
/* simple basename implementation: */
for (p = file; *p != '\0'; ++p) {
if (*p == '/') {
file = p + 1;
}
}
printk(KERN_INFO "%s <%s:%d>, pid %d: %s\n", func, file, line,
current->pid, cr_trace_buf);
spin_unlock(&cr_trace_lock);
}
#endif
/*
* Error/warning generation
*/
static CR_DEFINE_SPINLOCK(cr_errbuf_lock);
struct cr_errbuf_s {
unsigned short used, remain;
char buffer[0]; // GNU (not ISO C99) variable length array
};
cr_errbuf_t *cr_errbuf_alloc(void) {
cr_errbuf_t *p = (cr_errbuf_t *)__get_free_page(GFP_KERNEL);
p->used = 0;
p->remain = PAGE_SIZE - sizeof(cr_errbuf_t);
return p;
}
void cr_errbuf_free(cr_errbuf_t *eb) {
free_page((unsigned long)eb);
}
static int
cr_errbuf_vprintf(const char *lvl, cr_errbuf_t *eb, const char * fmt, va_list args)
{
char *p;
int len;
if (!eb || !eb->remain) {
#ifndef CR_QUIET
spin_lock(&cr_trace_lock);
vsprintf(cr_trace_buf, fmt, args);
printk("%sblcr: %s", lvl, cr_trace_buf);
spin_unlock(&cr_trace_lock);
#endif
return 0;
}
spin_lock(&cr_errbuf_lock);
p = eb->buffer + eb->used;
len = vsnprintf(p, eb->remain, fmt, args);
if (len > 0) {
#ifndef CR_QUIET
printk("%sblcr: %s", lvl, p);
#endif
if (len > eb->remain) {
eb->used += eb->remain;
eb->remain = 0;
} else {
eb->remain -= len;
eb->used += len;
}
}
spin_unlock(&cr_errbuf_lock);
return len;
}
int cr_errbuf_printf(const char *lvl, cr_errbuf_t *eb, const char * fmt, ...)
{
va_list args;
int len;
va_start(args, fmt);
len = cr_errbuf_vprintf(lvl, eb, fmt, args);
va_end(args);
return len;
}
/*
* Copy eb contents up to len bytes (including final nul)
* Returns space that would be required to accept full contents.
* If len is zero, buf is ignored.
*/
int cr_errbuf_read(char /*__user*/ *buf, unsigned int len, cr_errbuf_t *eb)
{
if (!eb) {
return -EINVAL;
}
if (len) {
/* Don't read past used space (rest of buffer uninitialized == security risk)
* or write beyond user's buffer.
*/
len = min((len-1), (unsigned int)(eb->used));
/* Copy to user if non-empty */
if (len && copy_to_user(buf, eb->buffer, len)) {
return -EFAULT;
}
/* Add nul termination */
if (put_user('\0', buf+len)) {
return -EFAULT;
}
}
return eb->used ? (eb->used + 1) : 0;
}
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