freebsd-dev/sys/cddl/dev/fbt/fbt.h
Mark Johnston c208cb9923 Allow multiple FBT probes to share a tracepoint.
With GNU ifuncs, multiple FBT probes may correspond to the same
instruction.  fbt_invop() assumed that this could not happen and
would return after the first probe found in the global FBT hash
table, which might not be the one that's enabled.  Fix the problem
on x86 by linking probes that share a tracepoint and having each
linked probe fire when the tracepoint is hit.

PR:		230846
Approved by:	re (gjb)
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D16921
2018-08-28 20:21:36 +00:00

82 lines
2.4 KiB
C

/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (the "License").
* You may not use this file except in compliance with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*
* Portions Copyright 2006-2008 John Birrell jb@freebsd.org
*
* $FreeBSD$
*
*/
/*
* Copyright 2006 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
#ifndef _FBT_H_
#define _FBT_H_
#include "fbt_isa.h"
/*
* fbt_probe is a bit of a misnomer. One of these structures is created for
* each trace point of an FBT probe. A probe might have multiple trace points
* (e.g., a function with multiple return instructions), and different probes
* might have a trace point at the same address (e.g., GNU ifuncs).
*/
typedef struct fbt_probe {
struct fbt_probe *fbtp_hashnext; /* global hash table linkage */
struct fbt_probe *fbtp_tracenext; /* next probe for tracepoint */
struct fbt_probe *fbtp_probenext; /* next tracepoint for probe */
int fbtp_enabled;
fbt_patchval_t *fbtp_patchpoint;
int8_t fbtp_rval;
fbt_patchval_t fbtp_patchval;
fbt_patchval_t fbtp_savedval;
uintptr_t fbtp_roffset;
dtrace_id_t fbtp_id;
const char *fbtp_name;
modctl_t *fbtp_ctl;
int fbtp_loadcnt;
int fbtp_symindx;
} fbt_probe_t;
struct linker_file;
struct linker_symval;
struct trapframe;
int fbt_invop(uintptr_t, struct trapframe *, uintptr_t);
void fbt_patch_tracepoint(fbt_probe_t *, fbt_patchval_t);
int fbt_provide_module_function(struct linker_file *, int,
struct linker_symval *, void *);
int fbt_excluded(const char *name);
extern dtrace_provider_id_t fbt_id;
extern fbt_probe_t **fbt_probetab;
extern int fbt_probetab_mask;
#define FBT_ADDR2NDX(addr) ((((uintptr_t)(addr)) >> 4) & fbt_probetab_mask)
#define FBT_PROBETAB_SIZE 0x8000 /* 32k entries -- 128K total */
#ifdef MALLOC_DECLARE
MALLOC_DECLARE(M_FBT);
#endif
#endif