xref: /linux/arch/x86/include/asm/ptrace.h (revision b889fcf63cb62e7fdb7816565e28f44dbe4a76a5)
1 #ifndef _ASM_X86_PTRACE_H
2 #define _ASM_X86_PTRACE_H
3 
4 #include <asm/segment.h>
5 #include <asm/page_types.h>
6 #include <uapi/asm/ptrace.h>
7 
8 #ifndef __ASSEMBLY__
9 #ifdef __i386__
10 
11 struct pt_regs {
12 	unsigned long bx;
13 	unsigned long cx;
14 	unsigned long dx;
15 	unsigned long si;
16 	unsigned long di;
17 	unsigned long bp;
18 	unsigned long ax;
19 	unsigned long ds;
20 	unsigned long es;
21 	unsigned long fs;
22 	unsigned long gs;
23 	unsigned long orig_ax;
24 	unsigned long ip;
25 	unsigned long cs;
26 	unsigned long flags;
27 	unsigned long sp;
28 	unsigned long ss;
29 };
30 
31 #else /* __i386__ */
32 
33 struct pt_regs {
34 	unsigned long r15;
35 	unsigned long r14;
36 	unsigned long r13;
37 	unsigned long r12;
38 	unsigned long bp;
39 	unsigned long bx;
40 /* arguments: non interrupts/non tracing syscalls only save up to here*/
41 	unsigned long r11;
42 	unsigned long r10;
43 	unsigned long r9;
44 	unsigned long r8;
45 	unsigned long ax;
46 	unsigned long cx;
47 	unsigned long dx;
48 	unsigned long si;
49 	unsigned long di;
50 	unsigned long orig_ax;
51 /* end of arguments */
52 /* cpu exception frame or undefined */
53 	unsigned long ip;
54 	unsigned long cs;
55 	unsigned long flags;
56 	unsigned long sp;
57 	unsigned long ss;
58 /* top of stack page */
59 };
60 
61 #endif /* !__i386__ */
62 
63 #include <linux/init.h>
64 #ifdef CONFIG_PARAVIRT
65 #include <asm/paravirt_types.h>
66 #endif
67 
68 struct cpuinfo_x86;
69 struct task_struct;
70 
71 extern unsigned long profile_pc(struct pt_regs *regs);
72 #define profile_pc profile_pc
73 
74 extern unsigned long
75 convert_ip_to_linear(struct task_struct *child, struct pt_regs *regs);
76 extern void send_sigtrap(struct task_struct *tsk, struct pt_regs *regs,
77 			 int error_code, int si_code);
78 
79 extern long syscall_trace_enter(struct pt_regs *);
80 extern void syscall_trace_leave(struct pt_regs *);
81 
82 static inline unsigned long regs_return_value(struct pt_regs *regs)
83 {
84 	return regs->ax;
85 }
86 
87 /*
88  * user_mode_vm(regs) determines whether a register set came from user mode.
89  * This is true if V8086 mode was enabled OR if the register set was from
90  * protected mode with RPL-3 CS value.  This tricky test checks that with
91  * one comparison.  Many places in the kernel can bypass this full check
92  * if they have already ruled out V8086 mode, so user_mode(regs) can be used.
93  */
94 static inline int user_mode(struct pt_regs *regs)
95 {
96 #ifdef CONFIG_X86_32
97 	return (regs->cs & SEGMENT_RPL_MASK) == USER_RPL;
98 #else
99 	return !!(regs->cs & 3);
100 #endif
101 }
102 
103 static inline int user_mode_vm(struct pt_regs *regs)
104 {
105 #ifdef CONFIG_X86_32
106 	return ((regs->cs & SEGMENT_RPL_MASK) | (regs->flags & X86_VM_MASK)) >=
107 		USER_RPL;
108 #else
109 	return user_mode(regs);
110 #endif
111 }
112 
113 static inline int v8086_mode(struct pt_regs *regs)
114 {
115 #ifdef CONFIG_X86_32
116 	return (regs->flags & X86_VM_MASK);
117 #else
118 	return 0;	/* No V86 mode support in long mode */
119 #endif
120 }
121 
122 #ifdef CONFIG_X86_64
123 static inline bool user_64bit_mode(struct pt_regs *regs)
124 {
125 #ifndef CONFIG_PARAVIRT
126 	/*
127 	 * On non-paravirt systems, this is the only long mode CPL 3
128 	 * selector.  We do not allow long mode selectors in the LDT.
129 	 */
130 	return regs->cs == __USER_CS;
131 #else
132 	/* Headers are too twisted for this to go in paravirt.h. */
133 	return regs->cs == __USER_CS || regs->cs == pv_info.extra_user_64bit_cs;
134 #endif
135 }
136 #endif
137 
138 #ifdef CONFIG_X86_32
139 extern unsigned long kernel_stack_pointer(struct pt_regs *regs);
140 #else
141 static inline unsigned long kernel_stack_pointer(struct pt_regs *regs)
142 {
143 	return regs->sp;
144 }
145 #endif
146 
147 #define GET_IP(regs) ((regs)->ip)
148 #define GET_FP(regs) ((regs)->bp)
149 #define GET_USP(regs) ((regs)->sp)
150 
151 #include <asm-generic/ptrace.h>
152 
153 /* Query offset/name of register from its name/offset */
154 extern int regs_query_register_offset(const char *name);
155 extern const char *regs_query_register_name(unsigned int offset);
156 #define MAX_REG_OFFSET (offsetof(struct pt_regs, ss))
157 
158 /**
159  * regs_get_register() - get register value from its offset
160  * @regs:	pt_regs from which register value is gotten.
161  * @offset:	offset number of the register.
162  *
163  * regs_get_register returns the value of a register. The @offset is the
164  * offset of the register in struct pt_regs address which specified by @regs.
165  * If @offset is bigger than MAX_REG_OFFSET, this returns 0.
166  */
167 static inline unsigned long regs_get_register(struct pt_regs *regs,
168 					      unsigned int offset)
169 {
170 	if (unlikely(offset > MAX_REG_OFFSET))
171 		return 0;
172 #ifdef CONFIG_X86_32
173 	/*
174 	 * Traps from the kernel do not save sp and ss.
175 	 * Use the helper function to retrieve sp.
176 	 */
177 	if (offset == offsetof(struct pt_regs, sp) &&
178 	    regs->cs == __KERNEL_CS)
179 		return kernel_stack_pointer(regs);
180 #endif
181 	return *(unsigned long *)((unsigned long)regs + offset);
182 }
183 
184 /**
185  * regs_within_kernel_stack() - check the address in the stack
186  * @regs:	pt_regs which contains kernel stack pointer.
187  * @addr:	address which is checked.
188  *
189  * regs_within_kernel_stack() checks @addr is within the kernel stack page(s).
190  * If @addr is within the kernel stack, it returns true. If not, returns false.
191  */
192 static inline int regs_within_kernel_stack(struct pt_regs *regs,
193 					   unsigned long addr)
194 {
195 	return ((addr & ~(THREAD_SIZE - 1))  ==
196 		(kernel_stack_pointer(regs) & ~(THREAD_SIZE - 1)));
197 }
198 
199 /**
200  * regs_get_kernel_stack_nth() - get Nth entry of the stack
201  * @regs:	pt_regs which contains kernel stack pointer.
202  * @n:		stack entry number.
203  *
204  * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which
205  * is specified by @regs. If the @n th entry is NOT in the kernel stack,
206  * this returns 0.
207  */
208 static inline unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs,
209 						      unsigned int n)
210 {
211 	unsigned long *addr = (unsigned long *)kernel_stack_pointer(regs);
212 	addr += n;
213 	if (regs_within_kernel_stack(regs, (unsigned long)addr))
214 		return *addr;
215 	else
216 		return 0;
217 }
218 
219 #define arch_has_single_step()	(1)
220 #ifdef CONFIG_X86_DEBUGCTLMSR
221 #define arch_has_block_step()	(1)
222 #else
223 #define arch_has_block_step()	(boot_cpu_data.x86 >= 6)
224 #endif
225 
226 #define ARCH_HAS_USER_SINGLE_STEP_INFO
227 
228 struct user_desc;
229 extern int do_get_thread_area(struct task_struct *p, int idx,
230 			      struct user_desc __user *info);
231 extern int do_set_thread_area(struct task_struct *p, int idx,
232 			      struct user_desc __user *info, int can_allocate);
233 
234 #endif /* !__ASSEMBLY__ */
235 #endif /* _ASM_X86_PTRACE_H */
236