freebsd-dev/sys/cddl/dev/systrace/systrace.c
Ryan Stone 493b584dbd Correct the types of the arguments to return probes of the syscall
provider.  Previously we were erroneously supplying the argument types of
the corresponding entry probe.

Reviewed by:	rpaulo
MFC after:	1 week
2011-11-11 03:49:42 +00:00

383 lines
10 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.
*/
#include <sys/cdefs.h>
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/conf.h>
#include <sys/cpuvar.h>
#include <sys/fcntl.h>
#include <sys/filio.h>
#include <sys/kdb.h>
#include <sys/kernel.h>
#include <sys/kmem.h>
#include <sys/kthread.h>
#include <sys/limits.h>
#include <sys/linker.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/module.h>
#include <sys/mutex.h>
#include <sys/poll.h>
#include <sys/proc.h>
#include <sys/selinfo.h>
#include <sys/smp.h>
#include <sys/sysproto.h>
#include <sys/sysent.h>
#include <sys/uio.h>
#include <sys/unistd.h>
#include <machine/stdarg.h>
#include <sys/dtrace.h>
#ifdef LINUX_SYSTRACE
#if defined(__amd64__)
#include <amd64/linux32/linux.h>
#include <amd64/linux32/linux32_proto.h>
#include <amd64/linux32/linux32_syscalls.c>
#include <amd64/linux32/linux32_systrace_args.c>
#define MODNAME "linux32"
#elif defined(__i386__)
#include <i386/linux/linux.h>
#include <i386/linux/linux_proto.h>
#include <i386/linux/linux_syscalls.c>
#include <i386/linux/linux_systrace_args.c>
#define MODNAME "linux"
#else
#error Only i386 and amd64 are supported.
#endif
extern struct sysent linux_sysent[];
#define MAXSYSCALL LINUX_SYS_MAXSYSCALL
#define SYSCALLNAMES linux_syscallnames
#define SYSENT linux_sysent
#elif defined(FREEBSD32_SYSTRACE)
/*
* The syscall arguments are processed into a DTrace argument array
* using a generated function. See sys/kern/makesyscalls.sh.
*/
#include <compat/freebsd32/freebsd32_proto.h>
#include <compat/freebsd32/freebsd32_util.h>
#include <compat/freebsd32/freebsd32_syscall.h>
#include <compat/freebsd32/freebsd32_systrace_args.c>
extern const char *freebsd32_syscallnames[];
#define MODNAME "freebsd32"
#define MAXSYSCALL FREEBSD32_SYS_MAXSYSCALL
#define SYSCALLNAMES freebsd32_syscallnames
#define SYSENT freebsd32_sysent
#else
/*
* The syscall arguments are processed into a DTrace argument array
* using a generated function. See sys/kern/makesyscalls.sh.
*/
#include <sys/syscall.h>
#include <kern/systrace_args.c>
#define MODNAME "freebsd"
#define MAXSYSCALL SYS_MAXSYSCALL
#define SYSCALLNAMES syscallnames
#define SYSENT sysent
#endif
#define PROVNAME "syscall"
#define DEVNAME "dtrace/systrace/" MODNAME
#define SYSTRACE_ARTIFICIAL_FRAMES 1
#define SYSTRACE_SHIFT 16
#define SYSTRACE_ISENTRY(x) ((int)(x) >> SYSTRACE_SHIFT)
#define SYSTRACE_SYSNUM(x) ((int)(x) & ((1 << SYSTRACE_SHIFT) - 1))
#define SYSTRACE_ENTRY(id) ((1 << SYSTRACE_SHIFT) | (id))
#define SYSTRACE_RETURN(id) (id)
#if ((1 << SYSTRACE_SHIFT) <= MAXSYSCALL)
#error 1 << SYSTRACE_SHIFT must exceed number of system calls
#endif
static d_open_t systrace_open;
static int systrace_unload(void);
static void systrace_getargdesc(void *, dtrace_id_t, void *, dtrace_argdesc_t *);
static void systrace_provide(void *, dtrace_probedesc_t *);
static void systrace_destroy(void *, dtrace_id_t, void *);
static void systrace_enable(void *, dtrace_id_t, void *);
static void systrace_disable(void *, dtrace_id_t, void *);
static void systrace_load(void *);
static struct cdevsw systrace_cdevsw = {
.d_version = D_VERSION,
.d_open = systrace_open,
#ifdef LINUX_SYSTRACE
.d_name = "systrace_" MODNAME,
#else
.d_name = "systrace",
#endif
};
static union {
const char **p_constnames;
char **pp_syscallnames;
} uglyhack = { SYSCALLNAMES };
static dtrace_pattr_t systrace_attr = {
{ DTRACE_STABILITY_EVOLVING, DTRACE_STABILITY_EVOLVING, DTRACE_CLASS_COMMON },
{ DTRACE_STABILITY_PRIVATE, DTRACE_STABILITY_PRIVATE, DTRACE_CLASS_UNKNOWN },
{ DTRACE_STABILITY_PRIVATE, DTRACE_STABILITY_PRIVATE, DTRACE_CLASS_ISA },
{ DTRACE_STABILITY_EVOLVING, DTRACE_STABILITY_EVOLVING, DTRACE_CLASS_COMMON },
{ DTRACE_STABILITY_PRIVATE, DTRACE_STABILITY_PRIVATE, DTRACE_CLASS_ISA },
};
static dtrace_pops_t systrace_pops = {
systrace_provide,
NULL,
systrace_enable,
systrace_disable,
NULL,
NULL,
systrace_getargdesc,
NULL,
NULL,
systrace_destroy
};
static struct cdev *systrace_cdev;
static dtrace_provider_id_t systrace_id;
#if !defined(LINUX_SYSTRACE)
/*
* Probe callback function.
*
* Note: This function is called for _all_ syscalls, regardless of which sysent
* array the syscall comes from. It could be a standard syscall or a
* compat syscall from something like Linux.
*/
static void
systrace_probe(u_int32_t id, int sysnum, struct sysent *sysent, void *params,
int ret)
{
int n_args = 0;
u_int64_t uargs[8];
memset(uargs, 0, sizeof(uargs));
/*
* Check if this syscall has an argument conversion function
* registered.
*/
if (params && sysent->sy_systrace_args_func != NULL) {
/*
* Convert the syscall parameters using the registered
* function.
*/
(*sysent->sy_systrace_args_func)(sysnum, params, uargs, &n_args);
} else if (params) {
/*
* Use the built-in system call argument conversion
* function to translate the syscall structure fields
* into the array of 64-bit values that DTrace
* expects.
*/
systrace_args(sysnum, params, uargs, &n_args);
} else {
/*
* Since params is NULL, this is a 'return' probe.
* Set arg0 and arg1 as the return value of this syscall.
*/
uargs[0] = uargs[1] = ret;
}
/* Process the probe using the converted argments. */
dtrace_probe(id, uargs[0], uargs[1], uargs[2], uargs[3], uargs[4]);
}
#endif
static void
systrace_getargdesc(void *arg, dtrace_id_t id, void *parg, dtrace_argdesc_t *desc)
{
int sysnum = SYSTRACE_SYSNUM((uintptr_t)parg);
if (SYSTRACE_ISENTRY((uintptr_t)parg))
systrace_entry_setargdesc(sysnum, desc->dtargd_ndx,
desc->dtargd_native, sizeof(desc->dtargd_native));
else
systrace_return_setargdesc(sysnum, desc->dtargd_ndx,
desc->dtargd_native, sizeof(desc->dtargd_native));
if (desc->dtargd_native[0] == '\0')
desc->dtargd_ndx = DTRACE_ARGNONE;
return;
}
static void
systrace_provide(void *arg, dtrace_probedesc_t *desc)
{
int i;
if (desc != NULL)
return;
for (i = 0; i < MAXSYSCALL; i++) {
if (dtrace_probe_lookup(systrace_id, MODNAME,
uglyhack.pp_syscallnames[i], "entry") != 0)
continue;
(void) dtrace_probe_create(systrace_id, MODNAME, uglyhack.pp_syscallnames[i],
"entry", SYSTRACE_ARTIFICIAL_FRAMES,
(void *)((uintptr_t)SYSTRACE_ENTRY(i)));
(void) dtrace_probe_create(systrace_id, MODNAME, uglyhack.pp_syscallnames[i],
"return", SYSTRACE_ARTIFICIAL_FRAMES,
(void *)((uintptr_t)SYSTRACE_RETURN(i)));
}
}
static void
systrace_destroy(void *arg, dtrace_id_t id, void *parg)
{
#ifdef DEBUG
int sysnum = SYSTRACE_SYSNUM((uintptr_t)parg);
/*
* There's nothing to do here but assert that we have actually been
* disabled.
*/
if (SYSTRACE_ISENTRY((uintptr_t)parg)) {
ASSERT(sysent[sysnum].sy_entry == 0);
} else {
ASSERT(sysent[sysnum].sy_return == 0);
}
#endif
}
static void
systrace_enable(void *arg, dtrace_id_t id, void *parg)
{
int sysnum = SYSTRACE_SYSNUM((uintptr_t)parg);
if (SYSENT[sysnum].sy_systrace_args_func == NULL)
SYSENT[sysnum].sy_systrace_args_func = systrace_args;
if (SYSTRACE_ISENTRY((uintptr_t)parg))
SYSENT[sysnum].sy_entry = id;
else
SYSENT[sysnum].sy_return = id;
}
static void
systrace_disable(void *arg, dtrace_id_t id, void *parg)
{
int sysnum = SYSTRACE_SYSNUM((uintptr_t)parg);
SYSENT[sysnum].sy_entry = 0;
SYSENT[sysnum].sy_return = 0;
}
static void
systrace_load(void *dummy)
{
/* Create the /dev/dtrace/systrace entry. */
systrace_cdev = make_dev(&systrace_cdevsw, 0, UID_ROOT, GID_WHEEL, 0600,
DEVNAME);
if (dtrace_register(PROVNAME, &systrace_attr, DTRACE_PRIV_USER,
NULL, &systrace_pops, NULL, &systrace_id) != 0)
return;
#if !defined(LINUX_SYSTRACE)
systrace_probe_func = systrace_probe;
#endif
}
static int
systrace_unload()
{
int error = 0;
if ((error = dtrace_unregister(systrace_id)) != 0)
return (error);
#if !defined(LINUX_SYSTRACE)
systrace_probe_func = NULL;
#endif
destroy_dev(systrace_cdev);
return (error);
}
static int
systrace_modevent(module_t mod __unused, int type, void *data __unused)
{
int error = 0;
switch (type) {
case MOD_LOAD:
break;
case MOD_UNLOAD:
break;
case MOD_SHUTDOWN:
break;
default:
error = EOPNOTSUPP;
break;
}
return (error);
}
static int
systrace_open(struct cdev *dev __unused, int oflags __unused, int devtype __unused, struct thread *td __unused)
{
return (0);
}
SYSINIT(systrace_load, SI_SUB_DTRACE_PROVIDER, SI_ORDER_ANY, systrace_load, NULL);
SYSUNINIT(systrace_unload, SI_SUB_DTRACE_PROVIDER, SI_ORDER_ANY, systrace_unload, NULL);
#ifdef LINUX_SYSTRACE
DEV_MODULE(systrace_linux32, systrace_modevent, NULL);
MODULE_VERSION(systrace_linux32, 1);
MODULE_DEPEND(systrace_linux32, linux, 1, 1, 1);
MODULE_DEPEND(systrace_linux32, dtrace, 1, 1, 1);
MODULE_DEPEND(systrace_linux32, opensolaris, 1, 1, 1);
#elif defined(FREEBSD32_SYSTRACE)
DEV_MODULE(systrace_freebsd32, systrace_modevent, NULL);
MODULE_VERSION(systrace_freebsd32, 1);
MODULE_DEPEND(systrace_freebsd32, dtrace, 1, 1, 1);
MODULE_DEPEND(systrace_freebsd32, opensolaris, 1, 1, 1);
#else
DEV_MODULE(systrace, systrace_modevent, NULL);
MODULE_VERSION(systrace, 1);
MODULE_DEPEND(systrace, dtrace, 1, 1, 1);
MODULE_DEPEND(systrace, opensolaris, 1, 1, 1);
#endif