freebsd-skq/sys/sys/ktrace.h
John Baldwin 75768576cc Add a new userland-visible ktrace flag KTR_DROP and an internal ktrace flag
KTRFAC_DROP to track instances when ktrace events are dropped due to the
request pool being exhausted.  When a thread tries to post a ktrace event
and is unable to due to no available ktrace request objects, it sets
KTRFAC_DROP in its process' p_traceflag field.  The next trace event to
successfully post from that process will set the KTR_DROP flag in the
header of the request going out and clear KTRFAC_DROP.

The KTR_DROP flag is the high bit in the type field of the ktr_header
structure.  Older kdump binaries will simply complain about an unknown type
when seeing an entry with KTR_DROP set.  Note that KTR_DROP being set on a
record in a ktrace file does not tell you anything except that at least one
event from this process was dropped prior to this event.  The user has no
way of knowing what types of events were dropped nor how many were dropped.

Requested by:	phk
2003-03-13 18:31:15 +00:00

193 lines
5.2 KiB
C

/*
* Copyright (c) 1988, 1993
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#)ktrace.h 8.1 (Berkeley) 6/2/93
* $FreeBSD$
*/
#ifndef _SYS_KTRACE_H_
#define _SYS_KTRACE_H_
/*
* operations to ktrace system call (KTROP(op))
*/
#define KTROP_SET 0 /* set trace points */
#define KTROP_CLEAR 1 /* clear trace points */
#define KTROP_CLEARFILE 2 /* stop all tracing to file */
#define KTROP(o) ((o)&3) /* macro to extract operation */
/*
* flags (ORed in with operation)
*/
#define KTRFLAG_DESCEND 4 /* perform op on all children too */
/*
* ktrace record header
*/
struct ktr_header {
int ktr_len; /* length of buf */
short ktr_type; /* trace record type */
pid_t ktr_pid; /* process id */
char ktr_comm[MAXCOMLEN+1]; /* command name */
struct timeval ktr_time; /* timestamp */
void *ktr_buffer;
};
/*
* Test for kernel trace point (MP SAFE).
*
* KTRCHECK() just checks that the type is enabled and is only for
* internal use in the ktrace subsystem. KTRPOINT() checks against
* ktrace recursion as well as checking that the type is enabled and
* is the public interface.
*/
#define KTRCHECK(td, type) ((td)->td_proc->p_traceflag & (1 << type))
#define KTRPOINT(td, type) (KTRCHECK((td), (type)) && !(td)->td_inktrace)
/*
* ktrace record types
*/
/*
* KTR_SYSCALL - system call record
*/
#define KTR_SYSCALL 1
struct ktr_syscall {
short ktr_code; /* syscall number */
short ktr_narg; /* number of arguments */
/*
* followed by ktr_narg register_t
*/
register_t ktr_args[1];
};
/*
* KTR_SYSRET - return from system call record
*/
#define KTR_SYSRET 2
struct ktr_sysret {
short ktr_code;
short ktr_eosys;
int ktr_error;
register_t ktr_retval;
};
/*
* KTR_NAMEI - namei record
*/
#define KTR_NAMEI 3
/* record contains pathname */
/*
* KTR_GENIO - trace generic process i/o
*/
#define KTR_GENIO 4
struct ktr_genio {
int ktr_fd;
enum uio_rw ktr_rw;
/*
* followed by data successfully read/written
*/
};
/*
* KTR_PSIG - trace processed signal
*/
#define KTR_PSIG 5
struct ktr_psig {
int signo;
sig_t action;
int code;
sigset_t mask;
};
/*
* KTR_CSW - trace context switches
*/
#define KTR_CSW 6
struct ktr_csw {
int out; /* 1 if switch out, 0 if switch in */
int user; /* 1 if usermode (ivcsw), 0 if kernel (vcsw) */
};
/*
* KTR_USER - data comming from userland
*/
#define KTR_USER_MAXLEN 2048 /* maximum length of passed data */
#define KTR_USER 7
/*
* KTR_DROP - If this bit is set in ktr_type, then at least one event
* between the previous record and this record was dropped.
*/
#define KTR_DROP 0x8000
/*
* kernel trace points (in p_traceflag)
*/
#define KTRFAC_MASK 0x00ffffff
#define KTRFAC_SYSCALL (1<<KTR_SYSCALL)
#define KTRFAC_SYSRET (1<<KTR_SYSRET)
#define KTRFAC_NAMEI (1<<KTR_NAMEI)
#define KTRFAC_GENIO (1<<KTR_GENIO)
#define KTRFAC_PSIG (1<<KTR_PSIG)
#define KTRFAC_CSW (1<<KTR_CSW)
#define KTRFAC_USER (1<<KTR_USER)
/*
* trace flags (also in p_traceflags)
*/
#define KTRFAC_ROOT 0x80000000 /* root set this trace */
#define KTRFAC_INHERIT 0x40000000 /* pass trace flags to children */
#define KTRFAC_DROP 0x20000000 /* last event was dropped */
#ifdef _KERNEL
extern struct mtx ktrace_mtx;
void ktrnamei(char *);
void ktrcsw(int, int);
void ktrpsig(int, sig_t, sigset_t *, int);
void ktrgenio(int, enum uio_rw, struct uio *, int);
void ktrsyscall(int, int narg, register_t args[]);
void ktrsysret(int, int, register_t);
#else
#include <sys/cdefs.h>
__BEGIN_DECLS
int ktrace(const char *, int, int, pid_t);
int utrace(const void *, size_t);
__END_DECLS
#endif
#endif