1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3 * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
4 */
5 #ifndef _ASM_PTRACE_H
6 #define _ASM_PTRACE_H
7
8 #include <asm/page.h>
9 #include <asm/thread_info.h>
10 #include <uapi/asm/ptrace.h>
11
12 /*
13 * This struct defines the way the registers are stored on the stack during
14 * a system call/exception. If you add a register here, please also add it to
15 * regoffset_table[] in arch/loongarch/kernel/ptrace.c.
16 */
17 struct pt_regs {
18 /* Main processor registers. */
19 unsigned long regs[32];
20
21 /* Original syscall arg0. */
22 unsigned long orig_a0;
23
24 /* Special CSR registers. */
25 unsigned long csr_era;
26 unsigned long csr_badvaddr;
27 unsigned long csr_crmd;
28 unsigned long csr_prmd;
29 unsigned long csr_euen;
30 unsigned long csr_ecfg;
31 unsigned long csr_estat;
32 unsigned long __last[0];
33 } __aligned(8);
34
regs_irqs_disabled(struct pt_regs * regs)35 static inline int regs_irqs_disabled(struct pt_regs *regs)
36 {
37 return arch_irqs_disabled_flags(regs->csr_prmd);
38 }
39
kernel_stack_pointer(struct pt_regs * regs)40 static inline unsigned long kernel_stack_pointer(struct pt_regs *regs)
41 {
42 return regs->regs[3];
43 }
44
45 /*
46 * Don't use asm-generic/ptrace.h it defines FP accessors that don't make
47 * sense on LoongArch. We rather want an error if they get invoked.
48 */
49
instruction_pointer_set(struct pt_regs * regs,unsigned long val)50 static inline void instruction_pointer_set(struct pt_regs *regs, unsigned long val)
51 {
52 regs->csr_era = val;
53 }
54
55 /* Query offset/name of register from its name/offset */
56 extern int regs_query_register_offset(const char *name);
57 #define MAX_REG_OFFSET (offsetof(struct pt_regs, __last))
58
59 /**
60 * regs_get_register() - get register value from its offset
61 * @regs: pt_regs from which register value is gotten.
62 * @offset: offset number of the register.
63 *
64 * regs_get_register returns the value of a register. The @offset is the
65 * offset of the register in struct pt_regs address which specified by @regs.
66 * If @offset is bigger than MAX_REG_OFFSET, this returns 0.
67 */
regs_get_register(struct pt_regs * regs,unsigned int offset)68 static inline unsigned long regs_get_register(struct pt_regs *regs, unsigned int offset)
69 {
70 if (unlikely(offset > MAX_REG_OFFSET))
71 return 0;
72
73 return *(unsigned long *)((unsigned long)regs + offset);
74 }
75
76 /**
77 * regs_within_kernel_stack() - check the address in the stack
78 * @regs: pt_regs which contains kernel stack pointer.
79 * @addr: address which is checked.
80 *
81 * regs_within_kernel_stack() checks @addr is within the kernel stack page(s).
82 * If @addr is within the kernel stack, it returns true. If not, returns false.
83 */
regs_within_kernel_stack(struct pt_regs * regs,unsigned long addr)84 static inline int regs_within_kernel_stack(struct pt_regs *regs, unsigned long addr)
85 {
86 return ((addr & ~(THREAD_SIZE - 1)) ==
87 (kernel_stack_pointer(regs) & ~(THREAD_SIZE - 1)));
88 }
89
90 /**
91 * regs_get_kernel_stack_nth() - get Nth entry of the stack
92 * @regs: pt_regs which contains kernel stack pointer.
93 * @n: stack entry number.
94 *
95 * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which
96 * is specified by @regs. If the @n th entry is NOT in the kernel stack,
97 * this returns 0.
98 */
regs_get_kernel_stack_nth(struct pt_regs * regs,unsigned int n)99 static inline unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, unsigned int n)
100 {
101 unsigned long *addr = (unsigned long *)kernel_stack_pointer(regs);
102
103 addr += n;
104 if (regs_within_kernel_stack(regs, (unsigned long)addr))
105 return *addr;
106 else
107 return 0;
108 }
109
110 struct task_struct;
111
112 /*
113 * Does the process account for user or for system time?
114 */
115 #define user_mode(regs) (((regs)->csr_prmd & PLV_MASK) == PLV_USER)
116
regs_return_value(struct pt_regs * regs)117 static inline long regs_return_value(struct pt_regs *regs)
118 {
119 return regs->regs[4];
120 }
121
122 #define instruction_pointer(regs) ((regs)->csr_era)
123 #define profile_pc(regs) instruction_pointer(regs)
124
125 extern void die(const char *, struct pt_regs *) __noreturn;
126
die_if_kernel(const char * str,struct pt_regs * regs)127 static inline void die_if_kernel(const char *str, struct pt_regs *regs)
128 {
129 if (unlikely(!user_mode(regs)))
130 die(str, regs);
131 }
132
133 #define current_pt_regs() \
134 ({ \
135 unsigned long sp = (unsigned long)__builtin_frame_address(0); \
136 (struct pt_regs *)((sp | (THREAD_SIZE - 1)) + 1 - 32) - 1; \
137 })
138
139 /* Helpers for working with the user stack pointer */
140
user_stack_pointer(struct pt_regs * regs)141 static inline unsigned long user_stack_pointer(struct pt_regs *regs)
142 {
143 return regs->regs[3];
144 }
145
user_stack_pointer_set(struct pt_regs * regs,unsigned long val)146 static inline void user_stack_pointer_set(struct pt_regs *regs,
147 unsigned long val)
148 {
149 regs->regs[3] = val;
150 }
151
152 #endif /* _ASM_PTRACE_H */
153