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/*
* Mach Operating System
* Copyright (c) 1991,1990,1989,1988,1987 Carnegie Mellon University
* All Rights Reserved.
*
* Permission to use, copy, modify and distribute this software and its
* documentation is hereby granted, provided that both the copyright
* notice and this permission notice appear in all copies of the
* software, derivative works or modified versions, and any portions
* thereof, and that both notices appear in supporting documentation.
*
* CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
* CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
* ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
*
* Carnegie Mellon requests users of this software to return to
*
* Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
* School of Computer Science
* Carnegie Mellon University
* Pittsburgh PA 15213-3890
*
* any improvements or extensions that they make and grant Carnegie Mellon
* the rights to redistribute these changes.
*/
/*
* xpr silent tracing circular buffer.
*/
#include <string.h>
#include <kern/debug.h>
#include <kern/xpr.h>
#include <kern/lock.h>
#include "cpu_number.h"
#include <machine/machspl.h>
#include <vm/vm_kern.h>
/*
* After a spontaneous reboot, it is desirable to look
* at the old xpr buffer. Assuming xprbootstrap allocates
* the buffer in the same place in physical memory and
* the reboot doesn't clear memory, this should work.
* xprptr will be reset, but the saved value should be OK.
* Just set xprenable false so the buffer isn't overwritten.
*/
decl_simple_lock_data(, xprlock)
boolean_t xprenable = TRUE; /* Enable xpr tracing */
int nxprbufs = 0; /* Number of contiguous xprbufs allocated */
int xprflags = 0; /* Bit mask of xpr flags enabled */
struct xprbuf *xprbase; /* Pointer to circular buffer nxprbufs*sizeof(xprbuf)*/
struct xprbuf *xprptr; /* Currently allocated xprbuf */
struct xprbuf *xprlast; /* Pointer to end of circular buffer */
/*VARARGS1*/
void xpr(
char *msg,
int arg1,
int arg2,
int arg3,
int arg4,
int arg5)
{
spl_t s;
struct xprbuf *x;
/* If we aren't initialized, ignore trace request */
if (!xprenable || (xprptr == 0))
return;
/* Guard against all interrupts and allocate next buffer. */
s = splhigh();
simple_lock(&xprlock);
x = xprptr++;
if (xprptr >= xprlast) {
/* wrap around */
xprptr = xprbase;
}
/* Save xprptr in allocated memory. */
*(struct xprbuf **)xprlast = xprptr;
simple_unlock(&xprlock);
splx(s);
x->msg = msg;
x->arg1 = arg1;
x->arg2 = arg2;
x->arg3 = arg3;
x->arg4 = arg4;
x->arg5 = arg5;
x->timestamp = XPR_TIMESTAMP;
x->cpuinfo = cpu_number();
}
void xprbootstrap(void)
{
vm_offset_t addr;
vm_size_t size;
kern_return_t kr;
simple_lock_init(&xprlock);
if (nxprbufs == 0)
return; /* assume XPR support not desired */
/* leave room at the end for a saved copy of xprptr */
size = nxprbufs * sizeof(struct xprbuf) + sizeof xprptr;
kr = kmem_alloc_wired(kernel_map, &addr, size);
if (kr != KERN_SUCCESS)
panic("xprbootstrap");
if (xprenable) {
/*
* If xprenable is set (the default) then we zero
* the buffer so xpr_dump doesn't encounter bad pointers.
* If xprenable isn't set, then we preserve
* the original contents of the buffer. This is useful
* if memory survives reboots, so xpr_dump can show
* the previous buffer contents.
*/
memset((void *) addr, 0, size);
}
xprbase = (struct xprbuf *) addr;
xprlast = &xprbase[nxprbufs];
xprptr = xprbase; /* setting xprptr enables tracing */
}
int xprinitial = 0;
void xprinit(void)
{
xprflags |= xprinitial;
}
#if MACH_KDB
#include <machine/setjmp.h>
#include <ddb/db_output.h>
extern jmp_buf_t *db_recover;
/*
* Print current content of xpr buffers (KDB's sake)
* Use stack order to make it understandable.
*
* Called as "!xpr_dump" this dumps the kernel's xpr buffer.
* Called with arguments, it can dump xpr buffers in user tasks,
* assuming they use the same format as the kernel.
*/
void xpr_dump(
struct xprbuf *base,
int nbufs)
{
jmp_buf_t db_jmpbuf;
jmp_buf_t *prev;
struct xprbuf *last, *ptr;
struct xprbuf *x;
int i;
spl_t s = s;
if (base == 0) {
base = xprbase;
nbufs = nxprbufs;
}
if (nbufs == 0)
return;
if (base == xprbase) {
s = splhigh();
simple_lock(&xprlock);
}
last = base + nbufs;
ptr = * (struct xprbuf **) last;
prev = db_recover;
if (_setjmp(db_recover = &db_jmpbuf) == 0)
for (x = ptr, i = 0; i < nbufs; i++) {
if (--x < base)
x = last - 1;
if (x->msg == 0)
break;
db_printf("<%d:%x:%x> ", x - base, x->cpuinfo, x->timestamp);
db_printf(x->msg, x->arg1,x->arg2,x->arg3,x->arg4,x->arg5);
}
db_recover = prev;
if (base == xprbase) {
simple_unlock(&xprlock);
(void) splx(s);
}
}
#endif /* MACH_KDB */
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