darling-xnu/bsd/sys/ktrace.h
2023-05-16 21:41:14 -07:00

140 lines
4.4 KiB
C

/*
* Copyright (c) 2015 Apple Inc. All rights reserved.
*
* @APPLE_OSREFERENCE_LICENSE_HEADER_START@
*
* This file contains Original Code and/or Modifications of Original Code
* as defined in and that are subject to the Apple Public Source License
* Version 2.0 (the 'License'). You may not use this file except in
* compliance with the License. The rights granted to you under the License
* may not be used to create, or enable the creation or redistribution of,
* unlawful or unlicensed copies of an Apple operating system, or to
* circumvent, violate, or enable the circumvention or violation of, any
* terms of an Apple operating system software license agreement.
*
* Please obtain a copy of the License at
* http://www.opensource.apple.com/apsl/ and read it before using this file.
*
* The Original Code and all software distributed under the License are
* distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
* Please see the License for the specific language governing rights and
* limitations under the License.
*
* @APPLE_OSREFERENCE_LICENSE_HEADER_END@
*/
#ifndef SYS_KTRACE_H
#define SYS_KTRACE_H
#include <stdint.h>
#include <kern/locks.h>
/* The states that ktrace can be in. */
enum ktrace_state {
/* No tool has configured ktrace. */
KTRACE_STATE_OFF = 0,
/* A foreground tool has configured ktrace. */
KTRACE_STATE_FG,
/* A background tool has configured ktrace. */
KTRACE_STATE_BG
};
void ktrace_lock(void);
void ktrace_unlock(void);
void ktrace_assert_lock_held(void);
void ktrace_start_single_threaded(void);
void ktrace_end_single_threaded(void);
/*
* Subsystems that use ktrace to manage ownership. These values are passed as
* part of the `*_mask` arguments in `ktrace_configure` and `ktrace_reset`.
*/
#define KTRACE_KDEBUG (1 << 0)
#define KTRACE_KPERF (1 << 1)
/*
* Used by subsystems to inform ktrace that a configuration is occurring.
* Validates whether the current process has privileges to configure
* ktrace. Pass the subsystem(s) being configured in config_mask.
*
* `ktrace_lock` must be held.
*
* Returns 0 if configuration is allowed, EPERM if process is not privileged,
* and EBUSY if ktrace is owned by another process.
*/
int ktrace_configure(uint32_t config_mask);
/*
* Tell ktrace to reset a configuration. Pass the susbsystem(s) that are to
* be reset in the reset_mask.
*
* `ktrace_lock` must be held.
*/
void ktrace_reset(uint32_t reset_mask);
/*
* Determine if the current process can read the configuration of ktrace.
* Only the owning process or a root privileged process is allowed.
*
* `ktrace_lock` must be held.
*
* Returns 0 if allowed, EPERM otherwise.
*/
int ktrace_read_check(void);
/*
* With certain boot-args, the kernel can start tracing without user space
* intervention. With `trace=<n_events>`, the kernel will start tracing at
* boot. With `trace_wake=<n_events>`, the kernel will start tracing on the
* wake path out of hibernation (on Intel only).
*
* In these cases, ktrace must be aware of the state changes. This function
* should be called whenever the kernel initiates configuring ktrace.
*
* `ktrace_lock` must be held.
*/
void ktrace_kernel_configure(uint32_t config_mask);
/*
* This KPI allows kernel systems to disable ktrace. ktrace will only be
* disabled if the state matches the provided state_to_match.
*
* This does not reset the configuration of any subsystems -- it just makes
* them stop logging events or sampling data.
*
* `ktrace_lock` must be held.
*/
void ktrace_disable(enum ktrace_state state_to_match);
/*
* Returns the pid of the process that owns ktrace. If ktrace is unowned,
* returns 0.
*
* `ktrace_lock` must be held.
*/
int ktrace_get_owning_pid(void);
/*
* Returns true if background tracing is active, false otherwise.
*
* `ktrace_lock` must be held.
*/
bool ktrace_background_active(void);
/*
* These functions exist for the transition for kperf to allow blessing other
* processes. They should not be used by other clients.
*/
extern bool ktrace_keep_ownership_on_reset;
extern int ktrace_root_set_owner_allowed;
int ktrace_set_owning_pid(int pid);
/* Initialize ktrace. Must only be called by the bootstrap thread. */
void ktrace_init(void);
#endif /* SYS_KTRACE_H */