dtrace_impl.h

Sun Solaris 10 中的 DTrace 组件的源代码。请参看: http://www.sun.com/software/solaris/observability.jsp

 * restart it; if a DTrace consumer wishes to restart tracing, it must reopen
 * the DTrace pseudodevice.
 */
typedef enum dtrace_activity {
	DTRACE_ACTIVITY_INACTIVE = 0,		/* not yet running */
	DTRACE_ACTIVITY_WARMUP,			/* while starting */
	DTRACE_ACTIVITY_ACTIVE,			/* running */
	DTRACE_ACTIVITY_DRAINING,		/* before stopping */
	DTRACE_ACTIVITY_COOLDOWN,		/* while stopping */
	DTRACE_ACTIVITY_STOPPED,		/* after stopping */
	DTRACE_ACTIVITY_KILLED			/* killed due to deadman */
} dtrace_activity_t;

/*
 * DTrace Helper Implementation
 *
 * A description of the helper architecture may be found in <sys/dtrace.h>.
 * Each process contains a pointer to its helpers in its p_dtrace_helpers
 * member.  This is a pointer to a dtrace_helpers structure, which contains an
 * array of pointers to dtrace_helper structures, helper variable state (shared
 * among a process's helpers) and a generation count.  (The generation count is
 * used to provide an identifier when a helper is added so that it may be
 * subsequently removed.)  The dtrace_helper structure is self-explanatory,
 * containing pointers to the objects needed to execute the helper.  Note that
 * helpers are _duplicated_ across fork(2), and destroyed on exec(2).  No more
 * than dtrace_helpers_max are allowed per-process.
 */
#define	DTRACE_HELPER_ACTION_USTACK	0
#define	DTRACE_NHELPER_ACTIONS		1

typedef struct dtrace_helper_action {
	dtrace_difo_t *dthp_predicate;		/* helper action predicate */
	int dthp_nactions;			/* number of actions */
	dtrace_difo_t **dthp_actions;		/* array of actions */
	int dthp_generation;			/* helper action generation */
	struct dtrace_helper_action *dthp_next;	/* next helper action */
} dtrace_helper_action_t;

typedef struct dtrace_helper_provider {
	dof_helper_t dthp_prov;			/* DOF w/ provider and probes */
	uint32_t dthp_ref;			/* reference count */
} dtrace_helper_provider_t;

typedef struct dtrace_helpers {
	dtrace_helper_action_t **dthps_actions;	/* array of helper actions */
	dtrace_vstate_t dthps_vstate;		/* helper action var. state */
	dtrace_helper_provider_t **dthps_provs;	/* array of providers */
	uint_t dthps_nprovs;			/* count of providers */
	int dthps_generation;			/* current generation */
	pid_t dthps_pid;			/* pid of associated proc */
	struct dtrace_helpers *dthps_next;	/* next pointer */
	struct dtrace_helpers *dthps_prev;	/* prev pointer */
} dtrace_helpers_t;

/*
 * DTrace Helper Action Tracing
 *
 * Debugging helper actions can be arduous.  To ease the development and
 * debugging of helpers, DTrace contains a tracing-framework-within-a-tracing-
 * framework: helper tracing.  If dtrace_helptrace_enabled is non-zero (which
 * it is by default on DEBUG kernels), all helper activity will be traced to a
 * global, in-kernel ring buffer.  Each entry includes a pointer to the specific
 * helper, the location within the helper, and a trace of all local variables.
 * The ring buffer may be displayed in a human-readable format with the
 * ::dtrace_helptrace mdb(1) dcmd.
 */
#define	DTRACE_HELPTRACE_NEXT	(-1)
#define	DTRACE_HELPTRACE_DONE	(-2)
#define	DTRACE_HELPTRACE_ERR	(-3)

typedef struct dtrace_helptrace {
	dtrace_helper_action_t	*dtht_helper;	/* helper action */
	int dtht_where;				/* where in helper action */
	int dtht_nlocals;			/* number of locals */
	uint64_t dtht_locals[1];		/* local variables */
} dtrace_helptrace_t;

/*
 * DTrace Credentials
 *
 * In probe context, we don't have the flexibility to examine the credentials
 * of the DTrace consumer that created a particular enabling.  Instead, we use
 * the Least Privilege interfaces to cache the consumer's credentials in a
 * dtrace_cred_t structure. That structure contains two important sets of
 * credentials that limit the consumer's breadth of visibility and what
 * actions the consumer may take.
 */
#define	DTRACE_CRV_ALLPROC		0x01
#define	DTRACE_CRV_KERNEL		0x02

#define	DTRACE_CRV_ALL		(DTRACE_CRV_ALLPROC | DTRACE_CRV_KERNEL)

#define	DTRACE_CRA_PROC			0x0001
#define	DTRACE_CRA_PROC_DESTRUCTIVE	0x0002
#define	DTRACE_CRA_PROC_CONTROL		0x0004
#define	DTRACE_CRA_KERNEL		0x0008
#define	DTRACE_CRA_KERNEL_DESTRUCTIVE	0x0010

#define	DTRACE_CRA_ALL		(DTRACE_CRA_PROC | \
	DTRACE_CRA_PROC_DESTRUCTIVE | DTRACE_CRA_PROC_CONTROL | \
	DTRACE_CRA_KERNEL | DTRACE_CRA_KERNEL_DESTRUCTIVE)

typedef struct dtrace_cred {
	uid_t			dcr_uid;
	gid_t			dcr_gid;
	uint8_t			dcr_destructive;
	uint8_t			dcr_visible;
	uint16_t		dcr_action;
} dtrace_cred_t;

/*
 * DTrace Consumer State
 *
 * Each DTrace consumer has an associated dtrace_state structure that contains
 * its in-kernel DTrace state -- including options, credentials, statistics and
 * pointers to ECBs, buffers, speculations and formats.  A dtrace_state
 * structure is also allocated for anonymous enablings.  When anonymous state
 * is grabbed, the grabbing consumers dts_anon pointer is set to the grabbed
 * dtrace_state structure.
 */
struct dtrace_state {
	dev_t dts_dev;				/* device */
	int dts_necbs;				/* total number of ECBs */
	dtrace_ecb_t **dts_ecbs;		/* array of ECBs */
	dtrace_epid_t dts_epid;			/* next EPID to allocate */
	size_t dts_needed;			/* greatest needed space */
	struct dtrace_state *dts_anon;		/* anon. state, if grabbed */
	dtrace_activity_t dts_activity;		/* current activity */
	dtrace_vstate_t dts_vstate;		/* variable state */
	dtrace_buffer_t *dts_buffer;		/* principal buffer */
	dtrace_buffer_t *dts_aggbuffer;		/* aggregation buffer */
	dtrace_speculation_t *dts_speculations;	/* speculation array */
	int dts_nspeculations;			/* number of speculations */
	int dts_naggregations;			/* number of aggregations */
	dtrace_aggregation_t **dts_aggregations; /* aggregation array */
	vmem_t *dts_aggid_arena;		/* arena for aggregation IDs */
	uint32_t dts_speculations_busy;		/* number of spec. busy */
	uint32_t dts_speculations_unavail;	/* number of spec unavail */
	uint64_t dts_errors;			/* total number of errors */
	uint32_t dts_reserve;			/* space reserved for END */
	hrtime_t dts_laststatus;		/* time of last status */
	cyclic_id_t dts_cleaner;		/* cleaning cyclic */
	cyclic_id_t dts_deadman;		/* deadman cyclic */
	hrtime_t dts_alive;			/* time last alive */
	char dts_speculates;			/* boolean: has speculations */
	char dts_destructive;			/* boolean: has dest. actions */
	int dts_nformats;			/* number of formats */
	char **dts_formats;			/* format string array */
	dtrace_optval_t dts_options[DTRACEOPT_MAX]; /* options */
	dtrace_cred_t dts_cred;			/* credentials */
};

struct dtrace_provider {
	dtrace_pattr_t dtpv_attr;		/* provider attributes */
	dtrace_ppriv_t dtpv_priv;		/* provider privileges */
	dtrace_pops_t dtpv_pops;		/* provider operations */
	char *dtpv_name;			/* provider name */
	void *dtpv_arg;				/* provider argument */
	uint_t dtpv_defunct;			/* boolean: defunct provider */
	uint_t dtpv_anonmatched;		/* boolean: anonymous matched */
	struct dtrace_provider *dtpv_next;	/* next provider */
};

struct dtrace_meta {
	dtrace_mops_t dtm_mops;			/* meta provider operations */
	char *dtm_name;				/* meta provider name */
	void *dtm_arg;				/* meta provider user arg */
	uint64_t dtm_count;			/* no. of associated provs. */
};

/*
 * DTrace Enablings
 *
 * An dtrace_enabling structure is used to track a collection of ECB
 * descriptions -- before they have been turned into actual ECBs.  This is
 * created as a result of DOF processing, and is generally used to generate
 * ECBs immediately thereafter.  When enablings are used in this way, they are
 * destroyed immediately after they have been used to generate ECBs.  Anonymous
 * enablings, however, may be created before the probes they wish to enable are
 * created.  For anonymous enablings then, the enabling is retained; as each
 * new module or provider registers with the framework, the anonymous enabling
 * is reevaluated, with any new match resulting in new ECBs.
 */
typedef struct dtrace_enabling {
	dtrace_ecbdesc_t **dten_desc;		/* ECB descriptions */
	int dten_ndesc;				/* number of ECB descriptions */
	int dten_maxdesc;			/* size of ECB array */
	dtrace_vstate_t *dten_vstate;		/* associated variable state */
} dtrace_enabling_t;

/*
 * DTrace Anonymous Enablings
 *
 * Anonymous enablings are DTrace enablings that are not associated with a
 * controlling process, but rather derive their enabling from DOF stored as
 * properties in the dtrace.conf file.  If there is an anonymous enabling, a
 * DTrace consumer state and enabling are created on attach.  The state may be
 * subsequently grabbed by the first consumer specifying the "grabanon"
 * option.  As long as an anonymous DTrace enabling exists, dtrace(7D) will
 * refuse to unload.
 */
typedef struct dtrace_anon {
	dtrace_state_t *dta_state;		/* DTrace consumer state */
	dtrace_enabling_t *dta_enabling;	/* pointer to enabling */
	processorid_t dta_beganon;		/* which CPU BEGIN ran on */
} dtrace_anon_t;

/*
 * DTrace Error Debugging
 */
#ifdef DEBUG
#define	DTRACE_ERRDEBUG
#endif

#ifdef DTRACE_ERRDEBUG

typedef struct dtrace_errhash {
	const char	*dter_msg;	/* error message */
	int		dter_count;	/* number of times seen */
} dtrace_errhash_t;

#define	DTRACE_ERRHASHSZ	256	/* must be > number of err msgs */

#endif	/* DTRACE_ERRDEBUG */

/*
 * DTrace Toxic Ranges
 *
 * DTrace supports safe loads from probe context; if the address turns out to
 * be invalid, a bit will be set by the kernel indicating that DTrace
 * encountered a memory error, and DTrace will propagate the error to the user
 * accordingly.  However, there may exist some regions of memory in which an
 * arbitrary load can change system state, and from which it is impossible to
 * recover from such a load after it has been attempted.  Examples of this may
 * include memory in which programmable I/O registers are mapped (for which a
 * read may have some implications for the device) or (in the specific case of
 * UltraSPARC-I and -II) the virtual address hole.  The platform is required
 * to make DTrace aware of these toxic ranges; DTrace will then check that
 * target addresses are not in a toxic range before attempting to issue a
 * safe load.
 */
typedef struct dtrace_toxrange {
	uintptr_t	dtt_base;		/* base of toxic range */
	uintptr_t	dtt_limit;		/* limit of toxic range */
} dtrace_toxrange_t;

extern uint64_t dtrace_getarg(int, int);
extern greg_t dtrace_getfp(void);
extern int dtrace_getipl(void);
extern uintptr_t dtrace_caller(int);
extern uint32_t dtrace_cas32(uint32_t *, uint32_t, uint32_t);
extern void *dtrace_casptr(void *, void *, void *);
extern void dtrace_copyin(uintptr_t, uintptr_t, size_t);
extern void dtrace_copyinstr(uintptr_t, uintptr_t, size_t);
extern void dtrace_copyout(uintptr_t, uintptr_t, size_t);
extern void dtrace_copyoutstr(uintptr_t, uintptr_t, size_t);
extern void dtrace_getpcstack(pc_t *, int, int, uint32_t *);
extern ulong_t dtrace_getreg(struct regs *, uint_t);
extern int dtrace_getstackdepth(int);
extern void dtrace_getupcstack(uint64_t *, int);
extern void dtrace_getufpstack(uint64_t *, uint64_t *, int);
extern uintptr_t dtrace_fulword(void *);
extern uint8_t dtrace_fuword8(void *);
extern uint16_t dtrace_fuword16(void *);
extern uint32_t dtrace_fuword32(void *);
extern uint64_t dtrace_fuword64(void *);
extern void dtrace_probe_error(dtrace_state_t *, dtrace_epid_t, int, int,
    int, uintptr_t);
extern int dtrace_assfail(const char *, const char *, int);
extern int dtrace_attached(void);
extern hrtime_t dtrace_gethrestime();

#ifdef __sparc
extern void dtrace_flush_windows(void);
extern void dtrace_flush_user_windows(void);
extern uint_t dtrace_getotherwin(void);
extern uint_t dtrace_getfprs(void);
#else
extern void dtrace_copy(uintptr_t, uintptr_t, size_t);
extern void dtrace_copystr(uintptr_t, uintptr_t, size_t);
#endif

/*
 * DTrace Assertions
 *
 * DTrace calls ASSERT from probe context.  To assure that a failed ASSERT
 * does not induce a markedly more catastrophic failure (e.g., one from which
 * a dump cannot be gleaned), DTrace must define its own ASSERT to be one that
 * may safely be called from probe context.  This header file must thus be
 * included by any DTrace component that calls ASSERT from probe context, and
 * _only_ by those components.  (The only exception to this is kernel
 * debugging infrastructure at user-level that doesn't depend on calling
 * ASSERT.)
 */
#undef ASSERT
#ifdef DEBUG
#define	ASSERT(EX)	((void)((EX) || \
			dtrace_assfail(#EX, __FILE__, __LINE__)))
#else
#define	ASSERT(X)	((void)0)
#endif

#ifdef	__cplusplus
}
#endif

#endif /* _SYS_DTRACE_IMPL_H */