1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Ptrace support for Hexagon
4 *
5 * Copyright (c) 2010-2013, The Linux Foundation. All rights reserved.
6 */
7
8 #include <linux/kernel.h>
9 #include <linux/sched.h>
10 #include <linux/sched/task_stack.h>
11 #include <linux/mm.h>
12 #include <linux/smp.h>
13 #include <linux/errno.h>
14 #include <linux/ptrace.h>
15 #include <linux/regset.h>
16 #include <linux/user.h>
17 #include <linux/elf.h>
18
19 #include <asm/user.h>
20
21 #if arch_has_single_step()
22 /* Both called from ptrace_resume */
23 void user_enable_single_step(struct task_struct *child)
24 {
25 pt_set_singlestep(task_pt_regs(child));
26 set_tsk_thread_flag(child, TIF_SINGLESTEP);
27 }
28
29 void user_disable_single_step(struct task_struct *child)
30 {
31 pt_clr_singlestep(task_pt_regs(child));
32 clear_tsk_thread_flag(child, TIF_SINGLESTEP);
33 }
34 #endif
35
36 static int genregs_get(struct task_struct *target,
37 const struct user_regset *regset,
38 struct membuf to)
39 {
40 struct pt_regs *regs = task_pt_regs(target);
41
42 /* The general idea here is that the copyout must happen in
43 * exactly the same order in which the userspace expects these
44 * regs. Now, the sequence in userspace does not match the
45 * sequence in the kernel, so everything past the 32 gprs
46 * happens one at a time.
47 */
48 membuf_write(&to, ®s->r00, 32*sizeof(unsigned long));
49 /* Must be exactly same sequence as struct user_regs_struct */
50 membuf_store(&to, regs->sa0);
51 membuf_store(&to, regs->lc0);
52 membuf_store(&to, regs->sa1);
53 membuf_store(&to, regs->lc1);
54 membuf_store(&to, regs->m0);
55 membuf_store(&to, regs->m1);
56 membuf_store(&to, regs->usr);
57 membuf_store(&to, regs->preds);
58 membuf_store(&to, regs->gp);
59 membuf_store(&to, regs->ugp);
60 membuf_store(&to, pt_elr(regs)); // pc
61 membuf_store(&to, (unsigned long)pt_cause(regs)); // cause
62 membuf_store(&to, pt_badva(regs)); // badva
63 #if CONFIG_HEXAGON_ARCH_VERSION >=4
64 membuf_store(&to, regs->cs0);
65 membuf_store(&to, regs->cs1);
66 return membuf_zero(&to, sizeof(unsigned long));
67 #else
68 return membuf_zero(&to, 3 * sizeof(unsigned long));
69 #endif
70 }
71
72 static int genregs_set(struct task_struct *target,
73 const struct user_regset *regset,
74 unsigned int pos, unsigned int count,
75 const void *kbuf, const void __user *ubuf)
76 {
77 int ret, ignore_offset;
78 unsigned long bucket;
79 struct pt_regs *regs = task_pt_regs(target);
80
81 if (!regs)
82 return -EIO;
83
84 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
85 ®s->r00, 0, 32*sizeof(unsigned long));
86
87 #define INEXT(KPT_REG, USR_REG) \
88 if (!ret) \
89 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, \
90 KPT_REG, offsetof(struct user_regs_struct, USR_REG), \
91 offsetof(struct user_regs_struct, USR_REG) + \
92 sizeof(unsigned long));
93
94 /* Must be exactly same sequence as struct user_regs_struct */
95 INEXT(®s->sa0, sa0);
96 INEXT(®s->lc0, lc0);
97 INEXT(®s->sa1, sa1);
98 INEXT(®s->lc1, lc1);
99 INEXT(®s->m0, m0);
100 INEXT(®s->m1, m1);
101 INEXT(®s->usr, usr);
102 INEXT(®s->preds, p3_0);
103 INEXT(®s->gp, gp);
104 INEXT(®s->ugp, ugp);
105 INEXT(&pt_elr(regs), pc);
106
107 /* CAUSE and BADVA aren't writeable. */
108 INEXT(&bucket, cause);
109 INEXT(&bucket, badva);
110
111 #if CONFIG_HEXAGON_ARCH_VERSION >=4
112 INEXT(®s->cs0, cs0);
113 INEXT(®s->cs1, cs1);
114 ignore_offset = offsetof(struct user_regs_struct, pad1);
115 #else
116 ignore_offset = offsetof(struct user_regs_struct, cs0);
117 #endif
118
119 /* Ignore the rest, if needed */
120 if (!ret)
121 user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
122 ignore_offset, -1);
123 else
124 return ret;
125
126 /*
127 * This is special; SP is actually restored by the VM via the
128 * special event record which is set by the special trap.
129 */
130 regs->hvmer.vmpsp = regs->r29;
131 return 0;
132 }
133
134 enum hexagon_regset {
135 REGSET_GENERAL,
136 };
137
138 static const struct user_regset hexagon_regsets[] = {
139 [REGSET_GENERAL] = {
140 .core_note_type = NT_PRSTATUS,
141 .n = ELF_NGREG,
142 .size = sizeof(unsigned long),
143 .align = sizeof(unsigned long),
144 .regset_get = genregs_get,
145 .set = genregs_set,
146 },
147 };
148
149 static const struct user_regset_view hexagon_user_view = {
150 .name = "hexagon",
151 .e_machine = ELF_ARCH,
152 .ei_osabi = ELF_OSABI,
153 .regsets = hexagon_regsets,
154 .e_flags = ELF_CORE_EFLAGS,
155 .n = ARRAY_SIZE(hexagon_regsets)
156 };
157
158 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
159 {
160 return &hexagon_user_view;
161 }
162
163 void ptrace_disable(struct task_struct *child)
164 {
165 /* Boilerplate - resolves to null inline if no HW single-step */
166 user_disable_single_step(child);
167 }
168
169 long arch_ptrace(struct task_struct *child, long request,
170 unsigned long addr, unsigned long data)
171 {
172 return ptrace_request(child, request, addr, data);
173 }
174
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