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