xref: /xnu-10002.81.5/osfmk/arm64/exception_asm.h (revision 5e3eaea39dcf651e66cb99ba7d70e32cc4a99587)
1 /*
2  * Copyright (c) 2018 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 #include <arm64/pac_asm.h>
30 #include <pexpert/arm64/board_config.h>
31 #include "assym.s"
32 
33 
34 #if XNU_MONITOR
35 /*
36  * Exit path defines; for controlling PPL -> kernel transitions.
37  * These should fit within a 32-bit integer, as the PPL trampoline packs them into a 32-bit field.
38  */
39 #define PPL_EXIT_DISPATCH   0 /* This is a clean exit after a PPL request. */
40 #define PPL_EXIT_PANIC_CALL 1 /* The PPL has called panic. */
41 #define PPL_EXIT_BAD_CALL   2 /* The PPL request failed. */
42 #define PPL_EXIT_EXCEPTION  3 /* The PPL took an exception. */
43 
44 #define KERNEL_MODE_ELR      ELR_GL11
45 #define KERNEL_MODE_FAR      FAR_GL11
46 #define KERNEL_MODE_ESR      ESR_GL11
47 #define KERNEL_MODE_SPSR     SPSR_GL11
48 #define KERNEL_MODE_VBAR     VBAR_GL11
49 #define KERNEL_MODE_TPIDR    TPIDR_GL11
50 
51 #define GUARDED_MODE_ELR     ELR_EL1
52 #define GUARDED_MODE_FAR     FAR_EL1
53 #define GUARDED_MODE_ESR     ESR_EL1
54 #define GUARDED_MODE_SPSR    SPSR_EL1
55 #define GUARDED_MODE_VBAR    VBAR_EL1
56 #define GUARDED_MODE_TPIDR   TPIDR_EL1
57 
58 /*
59  * LOAD_PMAP_CPU_DATA
60  *
61  * Loads the PPL per-CPU data array entry for the current CPU.
62  *   arg0 - Address of the PPL per-CPU data is returned through this
63  *   arg1 - Scratch register
64  *   arg2 - Scratch register
65  *
66  */
67 .macro LOAD_PMAP_CPU_DATA
68 	/* Get the CPU ID. */
69 	mrs		$0, MPIDR_EL1
70 	ubfx	$1, $0, MPIDR_AFF1_SHIFT, MPIDR_AFF1_WIDTH
71 	adrp	$2, EXT(cluster_offsets)@page
72 	add		$2, $2, EXT(cluster_offsets)@pageoff
73 	ldr		$1, [$2, $1, lsl #3]
74 
75 	and		$0, $0, MPIDR_AFF0_MASK
76 	add		$0, $0, $1
77 
78 	/* Get the PPL CPU data array. */
79 	adrp	$1, EXT(pmap_cpu_data_array)@page
80 	add		$1, $1, EXT(pmap_cpu_data_array)@pageoff
81 
82 	/*
83 	 * Sanity check the CPU ID (this is not a panic because this pertains to
84 	 * the hardware configuration; this should only fail if our
85 	 * understanding of the hardware is incorrect).
86 	 */
87 	cmp		$0, MAX_CPUS
88 	b.hs	.
89 
90 	mov		$2, PMAP_CPU_DATA_ARRAY_ENTRY_SIZE
91 	/* Get the PPL per-CPU data. */
92 	madd	$0, $0, $2, $1
93 .endmacro
94 
95 /*
96  * GET_PMAP_CPU_DATA
97  *
98  * Retrieves the PPL per-CPU data for the current CPU.
99  *   arg0 - Address of the PPL per-CPU data is returned through this
100  *   arg1 - Scratch register
101  *   arg2 - Scratch register
102  *
103  */
104 .macro GET_PMAP_CPU_DATA
105 	LOAD_PMAP_CPU_DATA $0, $1, $2
106 .endmacro
107 
108 #endif /* XNU_MONITOR */
109 
110 /*
111  * INIT_SAVED_STATE_FLAVORS
112  *
113  * Initializes the saved state flavors of a new saved state structure
114  *  arg0 - saved state pointer
115  *  arg1 - 32-bit scratch reg
116  *  arg2 - 32-bit scratch reg
117  */
118 .macro INIT_SAVED_STATE_FLAVORS
119 	mov		$1, ARM_SAVED_STATE64                                   // Set saved state to 64-bit flavor
120 	mov		$2, ARM_SAVED_STATE64_COUNT
121 	stp		$1, $2, [$0, SS_FLAVOR]
122 	mov		$1, ARM_NEON_SAVED_STATE64                              // Set neon state to 64-bit flavor
123 	str		$1, [$0, NS_FLAVOR]
124 	mov		$1, ARM_NEON_SAVED_STATE64_COUNT
125 	str		$1, [$0, NS_COUNT]
126 .endmacro
127 
128 /*
129  * SPILL_REGISTERS
130  *
131  * Spills the current set of registers (excluding x0, x1, sp) to the specified
132  * save area.
133  *
134  * On CPUs with PAC, the kernel "A" keys are used to create a thread signature.
135  * These keys are deliberately kept loaded into the CPU for later kernel use.
136  *
137  *   arg0 - KERNEL_MODE or HIBERNATE_MODE
138  *   arg1 - ADD_THREAD_SIGNATURE or POISON_THREAD_SIGNATURE
139  *   x0 - Address of the save area
140  *   x25 - Return the value of FPCR
141  */
142 #define KERNEL_MODE 0
143 #define HIBERNATE_MODE 1
144 
145 #define ADD_THREAD_SIGNATURE 0
146 #define POISON_THREAD_SIGNATURE 1
147 
148 .macro SPILL_REGISTERS	mode, signing_mode = ADD_THREAD_SIGNATURE
149 	stp		x2, x3, [x0, SS64_X2]                                   // Save remaining GPRs
150 	stp		x4, x5, [x0, SS64_X4]
151 	stp		x6, x7, [x0, SS64_X6]
152 	stp		x8, x9, [x0, SS64_X8]
153 	stp		x10, x11, [x0, SS64_X10]
154 	stp		x12, x13, [x0, SS64_X12]
155 	stp		x14, x15, [x0, SS64_X14]
156 	stp		x16, x17, [x0, SS64_X16]
157 	stp		x18, x19, [x0, SS64_X18]
158 	stp		x20, x21, [x0, SS64_X20]
159 	stp		x22, x23, [x0, SS64_X22]
160 	stp		x24, x25, [x0, SS64_X24]
161 	stp		x26, x27, [x0, SS64_X26]
162 	stp		x28, fp,  [x0, SS64_X28]
163 	str		lr, [x0, SS64_LR]
164 
165 	/* Save arm_neon_saved_state64 */
166 	stp		q0, q1, [x0, NS64_Q0]
167 	stp		q2, q3, [x0, NS64_Q2]
168 	stp		q4, q5, [x0, NS64_Q4]
169 	stp		q6, q7, [x0, NS64_Q6]
170 	stp		q8, q9, [x0, NS64_Q8]
171 	stp		q10, q11, [x0, NS64_Q10]
172 	stp		q12, q13, [x0, NS64_Q12]
173 	stp		q14, q15, [x0, NS64_Q14]
174 	stp		q16, q17, [x0, NS64_Q16]
175 	stp		q18, q19, [x0, NS64_Q18]
176 	stp		q20, q21, [x0, NS64_Q20]
177 	stp		q22, q23, [x0, NS64_Q22]
178 	stp		q24, q25, [x0, NS64_Q24]
179 	stp		q26, q27, [x0, NS64_Q26]
180 	stp		q28, q29, [x0, NS64_Q28]
181 	stp		q30, q31, [x0, NS64_Q30]
182 	mrs		x24, FPSR
183 	str		w24, [x0, NS64_FPSR]
184 	mrs		x25, FPCR
185 	str		w25, [x0, NS64_FPCR]
186 Lsave_neon_state_done_\@:
187 
188 	mrs		x22, ELR_EL1                                                     // Get exception link register
189 	mrs		x23, SPSR_EL1                                                   // Load CPSR into var reg x23
190 
191 #if defined(HAS_APPLE_PAC)
192 	.if \mode != HIBERNATE_MODE
193 
194 .if \signing_mode == POISON_THREAD_SIGNATURE
195 	mov		x21, #-1
196 	str		x21, [x0, SS64_JOPHASH]
197 .else
198 	/* Save x1 and LR to preserve across call */
199 	mov		x21, x1
200 	mov		x20, lr
201 
202 	/*
203 	 * Create thread state signature
204 	 *
205 	 * Arg0: The ARM context pointer
206 	 * Arg1: The PC value to sign
207 	 * Arg2: The CPSR value to sign
208 	 * Arg3: The LR value to sign
209 	 * Arg4: The X16 value to sign
210 	 * Arg5: The X17 value to sign
211 	 */
212 	mov		x1, x22
213 	mov		w2, w23
214 	mov		x3, x20
215 	mov		x4, x16
216 	mov		x5, x17
217 
218 	mrs		x19, SPSel
219 	msr		SPSel, #1
220 	bl		_ml_sign_thread_state
221 	msr		SPSel, x19
222 	mov		lr, x20
223 	mov		x1, x21
224 .endif
225 
226 	.endif
227 #endif /* defined(HAS_APPLE_PAC) */
228 
229 	str		x22, [x0, SS64_PC]                                               // Save ELR to PCB
230 	str		w23, [x0, SS64_CPSR]                                    // Save CPSR to PCB
231 
232 	mrs		x20, FAR_EL1
233 	mrs		x21, ESR_EL1
234 
235 	str		x20, [x0, SS64_FAR]
236 	str		w21, [x0, SS64_ESR]
237 .endmacro
238 
239 .macro DEADLOOP
240 	b	.
241 .endmacro
242 
243 /**
244  * Reloads SP with the current thread's interrupt stack.
245  *
246  * SP0 is expected to already be selected.  Clobbers x1 and tmp.
247  */
248 .macro SWITCH_TO_INT_STACK	tmp
249 	mrs		x1, TPIDR_EL1
250 	LOAD_INT_STACK	dst=x1, src=x1, tmp=\tmp
251 	mov		sp, x1			// Set the stack pointer to the interrupt stack
252 .endmacro
253 
254