/*
* Copyright (c) 2019 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
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*
* @APPLE_OSREFERENCE_LICENSE_HEADER_END@
*/
#ifndef _KERN_RESTARTABLE_H_
#define _KERN_RESTARTABLE_H_
#include <sys/cdefs.h>
#include <mach/message.h>
#include <mach/task.h>
__BEGIN_DECLS
/*!
* @typedef task_restartable_range_t
*
* @brief
* Describes a userspace recoverable range.
*
* @field location
* The pointer to the beginning of a restartable section.
*
* @field length
* The length of the critical section anchored at location.
*
* @field recovery_offs
* The offset from the initial location that should be used for the recovery
* codepath.
*
* @field flags
* Currently unused, pass 0.
*/
typedef struct {
mach_vm_address_t location;
unsigned short length;
unsigned short recovery_offs;
unsigned int flags;
} task_restartable_range_t;
typedef task_restartable_range_t *task_restartable_range_array_t;
/*!
* @function task_restartable_ranges_register
*
* @brief
* Register a set of restartable ranges for the current task.
*
* @param task
* The task to operate on
*
* @param ranges
* An array of address ranges for which PC resets are performed.
*
* @param count
* The number of address ranges.
*
* @returns
* - KERN_SUCCESS on success
* - KERN_FAILURE if the task isn't the current one
* - KERN_INVALID_ARGUMENT for various invalid inputs
* - KERN_NOT_SUPPORTED the request is not supported (second registration on
* release kernels, registration when the task has gone wide)
* - KERN_RESOURCE_SHORTAGE if not enough memory
*/
extern kern_return_t task_restartable_ranges_register(
task_t task,
task_restartable_range_array_t ranges,
mach_msg_type_number_t count);
/*!
* @function task_restartable_ranges_synchronize
*
* @brief
* Require for all threads in the task to reset their PC
* if within a restartable range.
*
* @param task
* The task to operate on (needs to be current task)
*
* @returns
* - KERN_SUCCESS
* - KERN_FAILURE if the task isn't the current one
*/
extern kern_return_t task_restartable_ranges_synchronize(task_t task);
/*!
* @const TASK_RESTARTABLE_OFFSET_MAX
* The maximum value length / recovery_offs can have.
*/
#define TASK_RESTARTABLE_OFFSET_MAX 4096u
#ifdef KERNEL_PRIVATE
#pragma GCC visibility push(hidden)
struct restartable_ranges;
/**
* @function restartable_init
*
* @brief
* Initializes the restartable module.
*/
extern void restartable_init(void);
/**
* @function restartable_ranges_release
*
* @brief
* Release a reference on a restartable range.
*/
extern void restartable_ranges_release(struct restartable_ranges *ranges);
/**
* @function thread_reset_pcs_in_range
*
* @brief
* Returns whether a non running thread is currently in a critical range.
*/
extern bool thread_reset_pcs_in_range(task_t task, struct thread *thread);
/**
* @function thread_reset_pcs_will_fault
*
* @brief
* Called by the platform code when about to handle a user fault exception.
*/
extern void thread_reset_pcs_will_fault(struct thread *thread);
/**
* @function thread_reset_pcs_done_faulting
*
* @brief
* Called by the platform code when being done handling a user fault
* exception.
*/
extern void thread_reset_pcs_done_faulting(struct thread *thread);
/**
* @function thread_reset_pcs_ast
*
* @brief
* Perform the work at the AST boundary to reset thread PCS.
*/
extern void thread_reset_pcs_ast(task_t task, struct thread *thread);
/**
* @function thread_reset_pcs_ack_IPI
*
* @brief
* Called by the scheduler code when acking the reset-pcs IPI.
*/
extern void thread_reset_pcs_ack_IPI(struct thread *thread);
#pragma GCC visibility pop
#endif // KERNEL_PRIVATE
__END_DECLS
#endif /* _KERN_RESTARTABLE_H_ */