1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Copyright 2010 Tilera Corporation. All Rights Reserved.
4 * Copyright 2015 Regents of the University of California
5 * Copyright 2017 SiFive
6 *
7 * Copied from arch/tile/kernel/ptrace.c
8 */
9
10 #include <asm/ptrace.h>
11 #include <asm/syscall.h>
12 #include <asm/thread_info.h>
13 #include <asm/switch_to.h>
14 #include <linux/audit.h>
15 #include <linux/ptrace.h>
16 #include <linux/elf.h>
17 #include <linux/regset.h>
18 #include <linux/sched.h>
19 #include <linux/sched/task_stack.h>
20 #include <linux/tracehook.h>
21
22 #define CREATE_TRACE_POINTS
23 #include <trace/events/syscalls.h>
24
25 enum riscv_regset {
26 REGSET_X,
27 #ifdef CONFIG_FPU
28 REGSET_F,
29 #endif
30 };
31
riscv_gpr_get(struct task_struct * target,const struct user_regset * regset,struct membuf to)32 static int riscv_gpr_get(struct task_struct *target,
33 const struct user_regset *regset,
34 struct membuf to)
35 {
36 return membuf_write(&to, task_pt_regs(target),
37 sizeof(struct user_regs_struct));
38 }
39
riscv_gpr_set(struct task_struct * target,const struct user_regset * regset,unsigned int pos,unsigned int count,const void * kbuf,const void __user * ubuf)40 static int riscv_gpr_set(struct task_struct *target,
41 const struct user_regset *regset,
42 unsigned int pos, unsigned int count,
43 const void *kbuf, const void __user *ubuf)
44 {
45 int ret;
46 struct pt_regs *regs;
47
48 regs = task_pt_regs(target);
49 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, regs, 0, -1);
50 return ret;
51 }
52
53 #ifdef CONFIG_FPU
riscv_fpr_get(struct task_struct * target,const struct user_regset * regset,struct membuf to)54 static int riscv_fpr_get(struct task_struct *target,
55 const struct user_regset *regset,
56 struct membuf to)
57 {
58 struct __riscv_d_ext_state *fstate = &target->thread.fstate;
59
60 if (target == current)
61 fstate_save(current, task_pt_regs(current));
62
63 membuf_write(&to, fstate, offsetof(struct __riscv_d_ext_state, fcsr));
64 membuf_store(&to, fstate->fcsr);
65 return membuf_zero(&to, 4); // explicitly pad
66 }
67
riscv_fpr_set(struct task_struct * target,const struct user_regset * regset,unsigned int pos,unsigned int count,const void * kbuf,const void __user * ubuf)68 static int riscv_fpr_set(struct task_struct *target,
69 const struct user_regset *regset,
70 unsigned int pos, unsigned int count,
71 const void *kbuf, const void __user *ubuf)
72 {
73 int ret;
74 struct __riscv_d_ext_state *fstate = &target->thread.fstate;
75
76 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, fstate, 0,
77 offsetof(struct __riscv_d_ext_state, fcsr));
78 if (!ret) {
79 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, fstate, 0,
80 offsetof(struct __riscv_d_ext_state, fcsr) +
81 sizeof(fstate->fcsr));
82 }
83
84 return ret;
85 }
86 #endif
87
88 static const struct user_regset riscv_user_regset[] = {
89 [REGSET_X] = {
90 .core_note_type = NT_PRSTATUS,
91 .n = ELF_NGREG,
92 .size = sizeof(elf_greg_t),
93 .align = sizeof(elf_greg_t),
94 .regset_get = riscv_gpr_get,
95 .set = riscv_gpr_set,
96 },
97 #ifdef CONFIG_FPU
98 [REGSET_F] = {
99 .core_note_type = NT_PRFPREG,
100 .n = ELF_NFPREG,
101 .size = sizeof(elf_fpreg_t),
102 .align = sizeof(elf_fpreg_t),
103 .regset_get = riscv_fpr_get,
104 .set = riscv_fpr_set,
105 },
106 #endif
107 };
108
109 static const struct user_regset_view riscv_user_native_view = {
110 .name = "riscv",
111 .e_machine = EM_RISCV,
112 .regsets = riscv_user_regset,
113 .n = ARRAY_SIZE(riscv_user_regset),
114 };
115
task_user_regset_view(struct task_struct * task)116 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
117 {
118 return &riscv_user_native_view;
119 }
120
ptrace_disable(struct task_struct * child)121 void ptrace_disable(struct task_struct *child)
122 {
123 clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
124 }
125
arch_ptrace(struct task_struct * child,long request,unsigned long addr,unsigned long data)126 long arch_ptrace(struct task_struct *child, long request,
127 unsigned long addr, unsigned long data)
128 {
129 long ret = -EIO;
130
131 switch (request) {
132 default:
133 ret = ptrace_request(child, request, addr, data);
134 break;
135 }
136
137 return ret;
138 }
139
140 /*
141 * Allows PTRACE_SYSCALL to work. These are called from entry.S in
142 * {handle,ret_from}_syscall.
143 */
do_syscall_trace_enter(struct pt_regs * regs)144 __visible int do_syscall_trace_enter(struct pt_regs *regs)
145 {
146 if (test_thread_flag(TIF_SYSCALL_TRACE))
147 if (tracehook_report_syscall_entry(regs))
148 return -1;
149
150 /*
151 * Do the secure computing after ptrace; failures should be fast.
152 * If this fails we might have return value in a0 from seccomp
153 * (via SECCOMP_RET_ERRNO/TRACE).
154 */
155 if (secure_computing() == -1)
156 return -1;
157
158 #ifdef CONFIG_HAVE_SYSCALL_TRACEPOINTS
159 if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))
160 trace_sys_enter(regs, syscall_get_nr(current, regs));
161 #endif
162
163 audit_syscall_entry(regs->a7, regs->a0, regs->a1, regs->a2, regs->a3);
164 return 0;
165 }
166
do_syscall_trace_exit(struct pt_regs * regs)167 __visible void do_syscall_trace_exit(struct pt_regs *regs)
168 {
169 audit_syscall_exit(regs);
170
171 if (test_thread_flag(TIF_SYSCALL_TRACE))
172 tracehook_report_syscall_exit(regs, 0);
173
174 #ifdef CONFIG_HAVE_SYSCALL_TRACEPOINTS
175 if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))
176 trace_sys_exit(regs, regs_return_value(regs));
177 #endif
178 }
179