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,struct membuf to)58 static int gpr_get(struct task_struct *target,
59 const struct user_regset *regset,
60 struct membuf to)
61 {
62 return membuf_write(&to, task_pt_regs(target), sizeof(struct pt_regs));
63 }
64
65 enum c6x_regset {
66 REGSET_GPR,
67 };
68
69 static const struct user_regset c6x_regsets[] = {
70 [REGSET_GPR] = {
71 .core_note_type = NT_PRSTATUS,
72 .n = ELF_NGREG,
73 .size = sizeof(u32),
74 .align = sizeof(u32),
75 .regset_get = gpr_get,
76 },
77 };
78
79 static const struct user_regset_view user_c6x_native_view = {
80 .name = "tic6x",
81 .e_machine = EM_TI_C6000,
82 .regsets = c6x_regsets,
83 .n = ARRAY_SIZE(c6x_regsets),
84 };
85
task_user_regset_view(struct task_struct * task)86 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
87 {
88 return &user_c6x_native_view;
89 }
90
91 /*
92 * Perform ptrace request
93 */
arch_ptrace(struct task_struct * child,long request,unsigned long addr,unsigned long data)94 long arch_ptrace(struct task_struct *child, long request,
95 unsigned long addr, unsigned long data)
96 {
97 int ret = 0;
98
99 switch (request) {
100 /*
101 * write the word at location addr.
102 */
103 case PTRACE_POKETEXT:
104 ret = generic_ptrace_pokedata(child, addr, data);
105 if (ret == 0 && request == PTRACE_POKETEXT)
106 flush_icache_range(addr, addr + 4);
107 break;
108 default:
109 ret = ptrace_request(child, request, addr, data);
110 break;
111 }
112
113 return ret;
114 }
115
116 /*
117 * handle tracing of system call entry
118 * - return the revised system call number or ULONG_MAX to cause ENOSYS
119 */
syscall_trace_entry(struct pt_regs * regs)120 asmlinkage unsigned long syscall_trace_entry(struct pt_regs *regs)
121 {
122 if (tracehook_report_syscall_entry(regs))
123 /* tracing decided this syscall should not happen, so
124 * We'll return a bogus call number to get an ENOSYS
125 * error, but leave the original number in
126 * regs->orig_a4
127 */
128 return ULONG_MAX;
129
130 return regs->b0;
131 }
132
133 /*
134 * handle tracing of system call exit
135 */
syscall_trace_exit(struct pt_regs * regs)136 asmlinkage void syscall_trace_exit(struct pt_regs *regs)
137 {
138 tracehook_report_syscall_exit(regs, 0);
139 }
140