xref: /linux/arch/x86/include/asm/ptrace.h (revision 93d90ad708b8da6efc0e487b66111aa9db7f70c7)
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 #ifdef CONFIG_PARAVIRT
64 #include <asm/paravirt_types.h>
65 #endif
66 
67 struct cpuinfo_x86;
68 struct task_struct;
69 
70 extern unsigned long profile_pc(struct pt_regs *regs);
71 #define profile_pc profile_pc
72 
73 extern unsigned long
74 convert_ip_to_linear(struct task_struct *child, struct pt_regs *regs);
75 extern void send_sigtrap(struct task_struct *tsk, struct pt_regs *regs,
76 			 int error_code, int si_code);
77 
78 
79 extern unsigned long syscall_trace_enter_phase1(struct pt_regs *, u32 arch);
80 extern long syscall_trace_enter_phase2(struct pt_regs *, u32 arch,
81 				       unsigned long phase1_result);
82 
83 extern long syscall_trace_enter(struct pt_regs *);
84 extern void syscall_trace_leave(struct pt_regs *);
85 
86 static inline unsigned long regs_return_value(struct pt_regs *regs)
87 {
88 	return regs->ax;
89 }
90 
91 /*
92  * user_mode_vm(regs) determines whether a register set came from user mode.
93  * This is true if V8086 mode was enabled OR if the register set was from
94  * protected mode with RPL-3 CS value.  This tricky test checks that with
95  * one comparison.  Many places in the kernel can bypass this full check
96  * if they have already ruled out V8086 mode, so user_mode(regs) can be used.
97  */
98 static inline int user_mode(struct pt_regs *regs)
99 {
100 #ifdef CONFIG_X86_32
101 	return (regs->cs & SEGMENT_RPL_MASK) == USER_RPL;
102 #else
103 	return !!(regs->cs & 3);
104 #endif
105 }
106 
107 static inline int user_mode_vm(struct pt_regs *regs)
108 {
109 #ifdef CONFIG_X86_32
110 	return ((regs->cs & SEGMENT_RPL_MASK) | (regs->flags & X86_VM_MASK)) >=
111 		USER_RPL;
112 #else
113 	return user_mode(regs);
114 #endif
115 }
116 
117 static inline int v8086_mode(struct pt_regs *regs)
118 {
119 #ifdef CONFIG_X86_32
120 	return (regs->flags & X86_VM_MASK);
121 #else
122 	return 0;	/* No V86 mode support in long mode */
123 #endif
124 }
125 
126 #ifdef CONFIG_X86_64
127 static inline bool user_64bit_mode(struct pt_regs *regs)
128 {
129 #ifndef CONFIG_PARAVIRT
130 	/*
131 	 * On non-paravirt systems, this is the only long mode CPL 3
132 	 * selector.  We do not allow long mode selectors in the LDT.
133 	 */
134 	return regs->cs == __USER_CS;
135 #else
136 	/* Headers are too twisted for this to go in paravirt.h. */
137 	return regs->cs == __USER_CS || regs->cs == pv_info.extra_user_64bit_cs;
138 #endif
139 }
140 
141 #define current_user_stack_pointer()	this_cpu_read(old_rsp)
142 /* ia32 vs. x32 difference */
143 #define compat_user_stack_pointer()	\
144 	(test_thread_flag(TIF_IA32) 	\
145 	 ? current_pt_regs()->sp 	\
146 	 : this_cpu_read(old_rsp))
147 #endif
148 
149 #ifdef CONFIG_X86_32
150 extern unsigned long kernel_stack_pointer(struct pt_regs *regs);
151 #else
152 static inline unsigned long kernel_stack_pointer(struct pt_regs *regs)
153 {
154 	return regs->sp;
155 }
156 #endif
157 
158 #define GET_IP(regs) ((regs)->ip)
159 #define GET_FP(regs) ((regs)->bp)
160 #define GET_USP(regs) ((regs)->sp)
161 
162 #include <asm-generic/ptrace.h>
163 
164 /* Query offset/name of register from its name/offset */
165 extern int regs_query_register_offset(const char *name);
166 extern const char *regs_query_register_name(unsigned int offset);
167 #define MAX_REG_OFFSET (offsetof(struct pt_regs, ss))
168 
169 /**
170  * regs_get_register() - get register value from its offset
171  * @regs:	pt_regs from which register value is gotten.
172  * @offset:	offset number of the register.
173  *
174  * regs_get_register returns the value of a register. The @offset is the
175  * offset of the register in struct pt_regs address which specified by @regs.
176  * If @offset is bigger than MAX_REG_OFFSET, this returns 0.
177  */
178 static inline unsigned long regs_get_register(struct pt_regs *regs,
179 					      unsigned int offset)
180 {
181 	if (unlikely(offset > MAX_REG_OFFSET))
182 		return 0;
183 #ifdef CONFIG_X86_32
184 	/*
185 	 * Traps from the kernel do not save sp and ss.
186 	 * Use the helper function to retrieve sp.
187 	 */
188 	if (offset == offsetof(struct pt_regs, sp) &&
189 	    regs->cs == __KERNEL_CS)
190 		return kernel_stack_pointer(regs);
191 #endif
192 	return *(unsigned long *)((unsigned long)regs + offset);
193 }
194 
195 /**
196  * regs_within_kernel_stack() - check the address in the stack
197  * @regs:	pt_regs which contains kernel stack pointer.
198  * @addr:	address which is checked.
199  *
200  * regs_within_kernel_stack() checks @addr is within the kernel stack page(s).
201  * If @addr is within the kernel stack, it returns true. If not, returns false.
202  */
203 static inline int regs_within_kernel_stack(struct pt_regs *regs,
204 					   unsigned long addr)
205 {
206 	return ((addr & ~(THREAD_SIZE - 1))  ==
207 		(kernel_stack_pointer(regs) & ~(THREAD_SIZE - 1)));
208 }
209 
210 /**
211  * regs_get_kernel_stack_nth() - get Nth entry of the stack
212  * @regs:	pt_regs which contains kernel stack pointer.
213  * @n:		stack entry number.
214  *
215  * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which
216  * is specified by @regs. If the @n th entry is NOT in the kernel stack,
217  * this returns 0.
218  */
219 static inline unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs,
220 						      unsigned int n)
221 {
222 	unsigned long *addr = (unsigned long *)kernel_stack_pointer(regs);
223 	addr += n;
224 	if (regs_within_kernel_stack(regs, (unsigned long)addr))
225 		return *addr;
226 	else
227 		return 0;
228 }
229 
230 #define arch_has_single_step()	(1)
231 #ifdef CONFIG_X86_DEBUGCTLMSR
232 #define arch_has_block_step()	(1)
233 #else
234 #define arch_has_block_step()	(boot_cpu_data.x86 >= 6)
235 #endif
236 
237 #define ARCH_HAS_USER_SINGLE_STEP_INFO
238 
239 /*
240  * When hitting ptrace_stop(), we cannot return using SYSRET because
241  * that does not restore the full CPU state, only a minimal set.  The
242  * ptracer can change arbitrary register values, which is usually okay
243  * because the usual ptrace stops run off the signal delivery path which
244  * forces IRET; however, ptrace_event() stops happen in arbitrary places
245  * in the kernel and don't force IRET path.
246  *
247  * So force IRET path after a ptrace stop.
248  */
249 #define arch_ptrace_stop_needed(code, info)				\
250 ({									\
251 	set_thread_flag(TIF_NOTIFY_RESUME);				\
252 	false;								\
253 })
254 
255 struct user_desc;
256 extern int do_get_thread_area(struct task_struct *p, int idx,
257 			      struct user_desc __user *info);
258 extern int do_set_thread_area(struct task_struct *p, int idx,
259 			      struct user_desc __user *info, int can_allocate);
260 
261 #endif /* !__ASSEMBLY__ */
262 #endif /* _ASM_X86_PTRACE_H */
263