1
2
3#include <linux/highmem.h>
4#include <linux/ptrace.h>
5#include <linux/uprobes.h>
6
7#include "decode-insn.h"
8
9#define UPROBE_TRAP_NR UINT_MAX
10
11bool is_swbp_insn(uprobe_opcode_t *insn)
12{
13#ifdef CONFIG_RISCV_ISA_C
14 return (*insn & 0xffff) == UPROBE_SWBP_INSN;
15#else
16 return *insn == UPROBE_SWBP_INSN;
17#endif
18}
19
20unsigned long uprobe_get_swbp_addr(struct pt_regs *regs)
21{
22 return instruction_pointer(regs);
23}
24
25int arch_uprobe_analyze_insn(struct arch_uprobe *auprobe, struct mm_struct *mm,
26 unsigned long addr)
27{
28 probe_opcode_t opcode;
29
30 opcode = *(probe_opcode_t *)(&auprobe->insn[0]);
31
32 auprobe->insn_size = GET_INSN_LENGTH(opcode);
33
34 switch (riscv_probe_decode_insn(&opcode, &auprobe->api)) {
35 case INSN_REJECTED:
36 return -EINVAL;
37
38 case INSN_GOOD_NO_SLOT:
39 auprobe->simulate = true;
40 break;
41
42 case INSN_GOOD:
43 auprobe->simulate = false;
44 break;
45
46 default:
47 return -EINVAL;
48 }
49
50 return 0;
51}
52
53int arch_uprobe_pre_xol(struct arch_uprobe *auprobe, struct pt_regs *regs)
54{
55 struct uprobe_task *utask = current->utask;
56
57 utask->autask.saved_cause = current->thread.bad_cause;
58 current->thread.bad_cause = UPROBE_TRAP_NR;
59
60 instruction_pointer_set(regs, utask->xol_vaddr);
61
62 regs->status &= ~SR_SPIE;
63
64 return 0;
65}
66
67int arch_uprobe_post_xol(struct arch_uprobe *auprobe, struct pt_regs *regs)
68{
69 struct uprobe_task *utask = current->utask;
70
71 WARN_ON_ONCE(current->thread.bad_cause != UPROBE_TRAP_NR);
72
73 instruction_pointer_set(regs, utask->vaddr + auprobe->insn_size);
74
75 regs->status |= SR_SPIE;
76
77 return 0;
78}
79
80bool arch_uprobe_xol_was_trapped(struct task_struct *t)
81{
82 if (t->thread.bad_cause != UPROBE_TRAP_NR)
83 return true;
84
85 return false;
86}
87
88bool arch_uprobe_skip_sstep(struct arch_uprobe *auprobe, struct pt_regs *regs)
89{
90 probe_opcode_t insn;
91 unsigned long addr;
92
93 if (!auprobe->simulate)
94 return false;
95
96 insn = *(probe_opcode_t *)(&auprobe->insn[0]);
97 addr = instruction_pointer(regs);
98
99 if (auprobe->api.handler)
100 auprobe->api.handler(insn, addr, regs);
101
102 return true;
103}
104
105void arch_uprobe_abort_xol(struct arch_uprobe *auprobe, struct pt_regs *regs)
106{
107 struct uprobe_task *utask = current->utask;
108
109
110
111
112
113 instruction_pointer_set(regs, utask->vaddr);
114
115 regs->status &= ~SR_SPIE;
116}
117
118bool arch_uretprobe_is_alive(struct return_instance *ret, enum rp_check ctx,
119 struct pt_regs *regs)
120{
121 if (ctx == RP_CHECK_CHAIN_CALL)
122 return regs->sp <= ret->stack;
123 else
124 return regs->sp < ret->stack;
125}
126
127unsigned long
128arch_uretprobe_hijack_return_addr(unsigned long trampoline_vaddr,
129 struct pt_regs *regs)
130{
131 unsigned long ra;
132
133 ra = regs->ra;
134
135 regs->ra = trampoline_vaddr;
136
137 return ra;
138}
139
140int arch_uprobe_exception_notify(struct notifier_block *self,
141 unsigned long val, void *data)
142{
143 return NOTIFY_DONE;
144}
145
146bool uprobe_breakpoint_handler(struct pt_regs *regs)
147{
148 if (uprobe_pre_sstep_notifier(regs))
149 return true;
150
151 return false;
152}
153
154bool uprobe_single_step_handler(struct pt_regs *regs)
155{
156 if (uprobe_post_sstep_notifier(regs))
157 return true;
158
159 return false;
160}
161
162void arch_uprobe_copy_ixol(struct page *page, unsigned long vaddr,
163 void *src, unsigned long len)
164{
165
166 void *kaddr = kmap_atomic(page);
167 void *dst = kaddr + (vaddr & ~PAGE_MASK);
168
169 memcpy(dst, src, len);
170
171
172 if (vaddr) {
173 dst += GET_INSN_LENGTH(*(probe_opcode_t *)src);
174 *(uprobe_opcode_t *)dst = __BUG_INSN_32;
175 }
176
177 kunmap_atomic(kaddr);
178
179
180
181
182
183
184
185 flush_dcache_page(page);
186}
187