1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Port on Texas Instruments TMS320C6x architecture
4 *
5 * Copyright (C) 2004, 2006, 2009, 2010, 2011 Texas Instruments Incorporated
6 * Author: Aurelien Jacquiot (aurelien.jacquiot@jaluna.com)
7 *
8 * Updated for 2.6.34: Mark Salter <msalter@redhat.com>
9 */
10 #include <linux/ptrace.h>
11 #include <linux/tracehook.h>
12 #include <linux/regset.h>
13 #include <linux/elf.h>
14 #include <linux/sched/task_stack.h>
15
16 #include <asm/cacheflush.h>
17
18 #define PT_REG_SIZE (sizeof(struct pt_regs))
19
20 /*
21 * Called by kernel/ptrace.c when detaching.
22 */
ptrace_disable(struct task_struct * child)23 void ptrace_disable(struct task_struct *child)
24 {
25 /* nothing to do */
26 }
27
28 /*
29 * Get a register number from live pt_regs for the specified task.
30 */
get_reg(struct task_struct * task,int regno)31 static inline long get_reg(struct task_struct *task, int regno)
32 {
33 long *addr = (long *)task_pt_regs(task);
34
35 if (regno == PT_TSR || regno == PT_CSR)
36 return 0;
37
38 return addr[regno];
39 }
40
41 /*
42 * Write contents of register REGNO in task TASK.
43 */
put_reg(struct task_struct * task,int regno,unsigned long data)44 static inline int put_reg(struct task_struct *task,
45 int regno,
46 unsigned long data)
47 {
48 unsigned long *addr = (unsigned long *)task_pt_regs(task);
49
50 if (regno != PT_TSR && regno != PT_CSR)
51 addr[regno] = data;
52
53 return 0;
54 }
55
56 /* regset get/set implementations */
57
gpr_get(struct task_struct * target,const struct user_regset * regset,unsigned int pos,unsigned int count,void * kbuf,void __user * ubuf)58 static int gpr_get(struct task_struct *target,
59 const struct user_regset *regset,
60 unsigned int pos, unsigned int count,
61 void *kbuf, void __user *ubuf)
62 {
63 struct pt_regs *regs = task_pt_regs(target);
64
65 return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
66 regs,
67 0, sizeof(*regs));
68 }
69
70 enum c6x_regset {
71 REGSET_GPR,
72 };
73
74 static const struct user_regset c6x_regsets[] = {
75 [REGSET_GPR] = {
76 .core_note_type = NT_PRSTATUS,
77 .n = ELF_NGREG,
78 .size = sizeof(u32),
79 .align = sizeof(u32),
80 .get = gpr_get,
81 },
82 };
83
84 static const struct user_regset_view user_c6x_native_view = {
85 .name = "tic6x",
86 .e_machine = EM_TI_C6000,
87 .regsets = c6x_regsets,
88 .n = ARRAY_SIZE(c6x_regsets),
89 };
90
task_user_regset_view(struct task_struct * task)91 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
92 {
93 return &user_c6x_native_view;
94 }
95
96 /*
97 * Perform ptrace request
98 */
arch_ptrace(struct task_struct * child,long request,unsigned long addr,unsigned long data)99 long arch_ptrace(struct task_struct *child, long request,
100 unsigned long addr, unsigned long data)
101 {
102 int ret = 0;
103
104 switch (request) {
105 /*
106 * write the word at location addr.
107 */
108 case PTRACE_POKETEXT:
109 ret = generic_ptrace_pokedata(child, addr, data);
110 if (ret == 0 && request == PTRACE_POKETEXT)
111 flush_icache_range(addr, addr + 4);
112 break;
113 default:
114 ret = ptrace_request(child, request, addr, data);
115 break;
116 }
117
118 return ret;
119 }
120
121 /*
122 * handle tracing of system call entry
123 * - return the revised system call number or ULONG_MAX to cause ENOSYS
124 */
syscall_trace_entry(struct pt_regs * regs)125 asmlinkage unsigned long syscall_trace_entry(struct pt_regs *regs)
126 {
127 if (tracehook_report_syscall_entry(regs))
128 /* tracing decided this syscall should not happen, so
129 * We'll return a bogus call number to get an ENOSYS
130 * error, but leave the original number in
131 * regs->orig_a4
132 */
133 return ULONG_MAX;
134
135 return regs->b0;
136 }
137
138 /*
139 * handle tracing of system call exit
140 */
syscall_trace_exit(struct pt_regs * regs)141 asmlinkage void syscall_trace_exit(struct pt_regs *regs)
142 {
143 tracehook_report_syscall_exit(regs, 0);
144 }
145