osfmk/kern/restartable.h

   1 /*
   2  * Copyright (c) 2019 Apple Inc. All rights reserved.
   3  *
   4  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. The rights granted to you under the License
  10  * may not be used to create, or enable the creation or redistribution of,
  11  * unlawful or unlicensed copies of an Apple operating system, or to
  12  * circumvent, violate, or enable the circumvention or violation of, any
  13  * terms of an Apple operating system software license agreement.
  14  *
  15  * Please obtain a copy of the License at
  16  * http://www.opensource.apple.com/apsl/ and read it before using this file.
  17  *
  18  * The Original Code and all software distributed under the License are
  19  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  20  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  21  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  22  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  23  * Please see the License for the specific language governing rights and
  24  * limitations under the License.
  25  *
  26  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
  27  */
  28
  29 #ifndef _KERN_RESTARTABLE_H_
  30 #define _KERN_RESTARTABLE_H_
  31
  32 #include <sys/cdefs.h>
  33 #include <mach/message.h>
  34 #include <mach/task.h>
  35
  36 __BEGIN_DECLS
  37
  38 /*!
  39  * @typedef task_restartable_range_t
  40  *
  41  * @brief
  42  * Describes a userspace recoverable range.
  43  *
  44  * @field location
  45  * The pointer to the beginning of a restartable section.
  46  *
  47  * @field length
  48  * The length of the critical section anchored at location.
  49  *
  50  * @field recovery_offs
  51  * The offset from the initial location that should be used for the recovery
  52  * codepath.
  53  *
  54  * @field flags
  55  * Currently unused, pass 0.
  56  */
  57 typedef struct {
  58         mach_vm_address_t location;
  59         unsigned short    length;
  60         unsigned short    recovery_offs;
  61         unsigned int      flags;
  62 } task_restartable_range_t;
  63
  64 typedef task_restartable_range_t *task_restartable_range_array_t;
  65
  66 /*!
  67  * @function task_restartable_ranges_register
  68  *
  69  * @brief
  70  * Register a set of restartable ranges for the current task.
  71  *
  72  * @param task
  73  * The task to operate on
  74  *
  75  * @param ranges
  76  * An array of address ranges for which PC resets are performed.
  77  *
  78  * @param count
  79  * The number of address ranges.
  80  *
  81  * @returns
  82  * - KERN_SUCCESS on success
  83  * - KERN_FAILURE if the task isn't the current one
  84  * - KERN_INVALID_ARGUMENT for various invalid inputs
  85  * - KERN_NOT_SUPPORTED the request is not supported (second registration on
  86  *   release kernels, registration when the task has gone wide)
  87  * - KERN_RESOURCE_SHORTAGE if not enough memory
  88  */
  89 extern kern_return_t task_restartable_ranges_register(
  90         task_t                         task,
  91         task_restartable_range_array_t ranges,
  92         mach_msg_type_number_t         count);
  93
  94 /*!
  95  * @function task_restartable_ranges_synchronize
  96  *
  97  * @brief
  98  * Require for all threads in the task to reset their PC
  99  * if within a restartable range.
 100  *
 101  * @param task
 102  * The task to operate on (needs to be current task)
 103  *
 104  * @returns
 105  * - KERN_SUCCESS
 106  * - KERN_FAILURE if the task isn't the current one
 107  */
 108 extern kern_return_t task_restartable_ranges_synchronize(task_t task);
 109
 110 /*!
 111  * @const TASK_RESTARTABLE_OFFSET_MAX
 112  * The maximum value length / recovery_offs can have.
 113  */
 114 #define TASK_RESTARTABLE_OFFSET_MAX  4096u
 115
 116 #ifdef KERNEL_PRIVATE
 117
 118 struct restartable_ranges;
 119
 120 /**
 121  * @function restartable_init
 122  *
 123  * @brief
 124  * Initializes the restartable module.
 125  */
 126 extern void restartable_init(void);
 127
 128 /**
 129  * @function restartable_ranges_release
 130  *
 131  * @brief
 132  * Release a reference on a restartable range.
 133  */
 134 extern void restartable_ranges_release(struct restartable_ranges *ranges);
 135
 136 /**
 137  * @function thread_reset_pcs_ast
 138  *
 139  * @brief
 140  * Perform the work at the AST boundary to reset thread PCS.
 141  */
 142 extern void thread_reset_pcs_ast(struct thread *thread);
 143
 144 #endif // KERNEL_PRIVATE
 145
 146 __END_DECLS
 147
 148 #endif  /* _KERN_RESTARTABLE_H_ */