xref: /linux/arch/arm64/include/asm/traps.h (revision 8a7c601e14576a22c2bbf7f67455ccf3f3d2737f)
1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3  * Based on arch/arm/include/asm/traps.h
4  *
5  * Copyright (C) 2012 ARM Ltd.
6  */
7 #ifndef __ASM_TRAP_H
8 #define __ASM_TRAP_H
9 
10 #include <linux/list.h>
11 #include <asm/esr.h>
12 #include <asm/ptrace.h>
13 #include <asm/sections.h>
14 
15 #ifdef CONFIG_ARMV8_DEPRECATED
16 bool try_emulate_armv8_deprecated(struct pt_regs *regs, u32 insn);
17 #else
18 static inline bool
19 try_emulate_armv8_deprecated(struct pt_regs *regs, u32 insn)
20 {
21 	return false;
22 }
23 #endif /* CONFIG_ARMV8_DEPRECATED */
24 
25 void force_signal_inject(int signal, int code, unsigned long address, unsigned long err);
26 void arm64_notify_segfault(unsigned long addr);
27 void arm64_force_sig_fault(int signo, int code, unsigned long far, const char *str);
28 void arm64_force_sig_fault_pkey(unsigned long far, const char *str, int pkey);
29 void arm64_force_sig_mceerr(int code, unsigned long far, short lsb, const char *str);
30 void arm64_force_sig_ptrace_errno_trap(int errno, unsigned long far, const char *str);
31 
32 int bug_brk_handler(struct pt_regs *regs, unsigned long esr);
33 int cfi_brk_handler(struct pt_regs *regs, unsigned long esr);
34 int reserved_fault_brk_handler(struct pt_regs *regs, unsigned long esr);
35 int kasan_brk_handler(struct pt_regs *regs, unsigned long esr);
36 int ubsan_brk_handler(struct pt_regs *regs, unsigned long esr);
37 
38 int early_brk64(unsigned long addr, unsigned long esr, struct pt_regs *regs);
39 void dump_kernel_instr(unsigned long kaddr);
40 
41 /*
42  * Move regs->pc to next instruction and do necessary setup before it
43  * is executed.
44  */
45 void arm64_skip_faulting_instruction(struct pt_regs *regs, unsigned long size);
46 
47 static inline int __in_irqentry_text(unsigned long ptr)
48 {
49 	return ptr >= (unsigned long)&__irqentry_text_start &&
50 	       ptr < (unsigned long)&__irqentry_text_end;
51 }
52 
53 static inline int in_entry_text(unsigned long ptr)
54 {
55 	return ptr >= (unsigned long)&__entry_text_start &&
56 	       ptr < (unsigned long)&__entry_text_end;
57 }
58 
59 /*
60  * CPUs with the RAS extensions have an Implementation-Defined-Syndrome bit
61  * to indicate whether this ESR has a RAS encoding. CPUs without this feature
62  * have a ISS-Valid bit in the same position.
63  * If this bit is set, we know its not a RAS SError.
64  * If its clear, we need to know if the CPU supports RAS. Uncategorized RAS
65  * errors share the same encoding as an all-zeros encoding from a CPU that
66  * doesn't support RAS.
67  */
68 static inline bool arm64_is_ras_serror(unsigned long esr)
69 {
70 	WARN_ON(preemptible());
71 
72 	if (esr & ESR_ELx_IDS)
73 		return false;
74 
75 	if (this_cpu_has_cap(ARM64_HAS_RAS_EXTN))
76 		return true;
77 	else
78 		return false;
79 }
80 
81 /*
82  * Return the AET bits from a RAS SError's ESR.
83  *
84  * It is implementation defined whether Uncategorized errors are containable.
85  * We treat them as Uncontainable.
86  * Non-RAS SError's are reported as Uncontained/Uncategorized.
87  */
88 static inline unsigned long arm64_ras_serror_get_severity(unsigned long esr)
89 {
90 	unsigned long aet = esr & ESR_ELx_AET;
91 
92 	if (!arm64_is_ras_serror(esr)) {
93 		/* Not a RAS error, we can't interpret the ESR. */
94 		return ESR_ELx_AET_UC;
95 	}
96 
97 	/*
98 	 * AET is RES0 if 'the value returned in the DFSC field is not
99 	 * [ESR_ELx_FSC_SERROR]'
100 	 */
101 	if ((esr & ESR_ELx_FSC) != ESR_ELx_FSC_SERROR) {
102 		/* No severity information : Uncategorized */
103 		return ESR_ELx_AET_UC;
104 	}
105 
106 	return aet;
107 }
108 
109 bool arm64_is_fatal_ras_serror(struct pt_regs *regs, unsigned long esr);
110 void __noreturn arm64_serror_panic(struct pt_regs *regs, unsigned long esr);
111 
112 static inline void arm64_mops_reset_regs(struct user_pt_regs *regs, unsigned long esr)
113 {
114 	bool wrong_option = esr & ESR_ELx_MOPS_ISS_WRONG_OPTION;
115 	bool option_a = esr & ESR_ELx_MOPS_ISS_OPTION_A;
116 	int dstreg = ESR_ELx_MOPS_ISS_DESTREG(esr);
117 	int srcreg = ESR_ELx_MOPS_ISS_SRCREG(esr);
118 	int sizereg = ESR_ELx_MOPS_ISS_SIZEREG(esr);
119 	unsigned long dst, size;
120 
121 	dst = regs->regs[dstreg];
122 	size = regs->regs[sizereg];
123 
124 	/*
125 	 * Put the registers back in the original format suitable for a
126 	 * prologue instruction, using the generic return routine from the
127 	 * Arm ARM (DDI 0487I.a) rules CNTMJ and MWFQH.
128 	 */
129 	if (esr & ESR_ELx_MOPS_ISS_MEM_INST) {
130 		/* SET* instruction */
131 		if (option_a ^ wrong_option) {
132 			/* Format is from Option A; forward set */
133 			regs->regs[dstreg] = dst + size;
134 			regs->regs[sizereg] = -size;
135 		}
136 	} else {
137 		/* CPY* instruction */
138 		unsigned long src = regs->regs[srcreg];
139 		if (!(option_a ^ wrong_option)) {
140 			/* Format is from Option B */
141 			if (regs->pstate & PSR_N_BIT) {
142 				/* Backward copy */
143 				regs->regs[dstreg] = dst - size;
144 				regs->regs[srcreg] = src - size;
145 			}
146 		} else {
147 			/* Format is from Option A */
148 			if (size & BIT(63)) {
149 				/* Forward copy */
150 				regs->regs[dstreg] = dst + size;
151 				regs->regs[srcreg] = src + size;
152 				regs->regs[sizereg] = -size;
153 			}
154 		}
155 	}
156 
157 	if (esr & ESR_ELx_MOPS_ISS_FROM_EPILOGUE)
158 		regs->pc -= 8;
159 	else
160 		regs->pc -= 4;
161 }
162 #endif
163