xref: /openbmc/linux/arch/x86/include/asm/ptrace.h (revision 80483c3a)
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 /*
35  * C ABI says these regs are callee-preserved. They aren't saved on kernel entry
36  * unless syscall needs a complete, fully filled "struct pt_regs".
37  */
38 	unsigned long r15;
39 	unsigned long r14;
40 	unsigned long r13;
41 	unsigned long r12;
42 	unsigned long bp;
43 	unsigned long bx;
44 /* These regs are callee-clobbered. Always saved on kernel entry. */
45 	unsigned long r11;
46 	unsigned long r10;
47 	unsigned long r9;
48 	unsigned long r8;
49 	unsigned long ax;
50 	unsigned long cx;
51 	unsigned long dx;
52 	unsigned long si;
53 	unsigned long di;
54 /*
55  * On syscall entry, this is syscall#. On CPU exception, this is error code.
56  * On hw interrupt, it's IRQ number:
57  */
58 	unsigned long orig_ax;
59 /* Return frame for iretq */
60 	unsigned long ip;
61 	unsigned long cs;
62 	unsigned long flags;
63 	unsigned long sp;
64 	unsigned long ss;
65 /* top of stack page */
66 };
67 
68 #endif /* !__i386__ */
69 
70 #ifdef CONFIG_PARAVIRT
71 #include <asm/paravirt_types.h>
72 #endif
73 
74 struct cpuinfo_x86;
75 struct task_struct;
76 
77 extern unsigned long profile_pc(struct pt_regs *regs);
78 #define profile_pc profile_pc
79 
80 extern unsigned long
81 convert_ip_to_linear(struct task_struct *child, struct pt_regs *regs);
82 extern void send_sigtrap(struct task_struct *tsk, struct pt_regs *regs,
83 			 int error_code, int si_code);
84 
85 
86 static inline unsigned long regs_return_value(struct pt_regs *regs)
87 {
88 	return regs->ax;
89 }
90 
91 /*
92  * user_mode(regs) determines whether a register set came from user
93  * mode.  On x86_32, this is true if V8086 mode was enabled OR if the
94  * register set was from protected mode with RPL-3 CS value.  This
95  * tricky test checks that with one comparison.
96  *
97  * On x86_64, vm86 mode is mercifully nonexistent, and we don't need
98  * the extra check.
99  */
100 static inline int user_mode(struct pt_regs *regs)
101 {
102 #ifdef CONFIG_X86_32
103 	return ((regs->cs & SEGMENT_RPL_MASK) | (regs->flags & X86_VM_MASK)) >= USER_RPL;
104 #else
105 	return !!(regs->cs & 3);
106 #endif
107 }
108 
109 static inline int v8086_mode(struct pt_regs *regs)
110 {
111 #ifdef CONFIG_X86_32
112 	return (regs->flags & X86_VM_MASK);
113 #else
114 	return 0;	/* No V86 mode support in long mode */
115 #endif
116 }
117 
118 #ifdef CONFIG_X86_64
119 static inline bool user_64bit_mode(struct pt_regs *regs)
120 {
121 #ifndef CONFIG_PARAVIRT
122 	/*
123 	 * On non-paravirt systems, this is the only long mode CPL 3
124 	 * selector.  We do not allow long mode selectors in the LDT.
125 	 */
126 	return regs->cs == __USER_CS;
127 #else
128 	/* Headers are too twisted for this to go in paravirt.h. */
129 	return regs->cs == __USER_CS || regs->cs == pv_info.extra_user_64bit_cs;
130 #endif
131 }
132 
133 #define current_user_stack_pointer()	current_pt_regs()->sp
134 #define compat_user_stack_pointer()	current_pt_regs()->sp
135 #endif
136 
137 #ifdef CONFIG_X86_32
138 extern unsigned long kernel_stack_pointer(struct pt_regs *regs);
139 #else
140 static inline unsigned long kernel_stack_pointer(struct pt_regs *regs)
141 {
142 	return regs->sp;
143 }
144 #endif
145 
146 #define GET_IP(regs) ((regs)->ip)
147 #define GET_FP(regs) ((regs)->bp)
148 #define GET_USP(regs) ((regs)->sp)
149 
150 #include <asm-generic/ptrace.h>
151 
152 /* Query offset/name of register from its name/offset */
153 extern int regs_query_register_offset(const char *name);
154 extern const char *regs_query_register_name(unsigned int offset);
155 #define MAX_REG_OFFSET (offsetof(struct pt_regs, ss))
156 
157 /**
158  * regs_get_register() - get register value from its offset
159  * @regs:	pt_regs from which register value is gotten.
160  * @offset:	offset number of the register.
161  *
162  * regs_get_register returns the value of a register. The @offset is the
163  * offset of the register in struct pt_regs address which specified by @regs.
164  * If @offset is bigger than MAX_REG_OFFSET, this returns 0.
165  */
166 static inline unsigned long regs_get_register(struct pt_regs *regs,
167 					      unsigned int offset)
168 {
169 	if (unlikely(offset > MAX_REG_OFFSET))
170 		return 0;
171 #ifdef CONFIG_X86_32
172 	/*
173 	 * Traps from the kernel do not save sp and ss.
174 	 * Use the helper function to retrieve sp.
175 	 */
176 	if (offset == offsetof(struct pt_regs, sp) &&
177 	    regs->cs == __KERNEL_CS)
178 		return kernel_stack_pointer(regs);
179 #endif
180 	return *(unsigned long *)((unsigned long)regs + offset);
181 }
182 
183 /**
184  * regs_within_kernel_stack() - check the address in the stack
185  * @regs:	pt_regs which contains kernel stack pointer.
186  * @addr:	address which is checked.
187  *
188  * regs_within_kernel_stack() checks @addr is within the kernel stack page(s).
189  * If @addr is within the kernel stack, it returns true. If not, returns false.
190  */
191 static inline int regs_within_kernel_stack(struct pt_regs *regs,
192 					   unsigned long addr)
193 {
194 	return ((addr & ~(THREAD_SIZE - 1))  ==
195 		(kernel_stack_pointer(regs) & ~(THREAD_SIZE - 1)));
196 }
197 
198 /**
199  * regs_get_kernel_stack_nth() - get Nth entry of the stack
200  * @regs:	pt_regs which contains kernel stack pointer.
201  * @n:		stack entry number.
202  *
203  * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which
204  * is specified by @regs. If the @n th entry is NOT in the kernel stack,
205  * this returns 0.
206  */
207 static inline unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs,
208 						      unsigned int n)
209 {
210 	unsigned long *addr = (unsigned long *)kernel_stack_pointer(regs);
211 	addr += n;
212 	if (regs_within_kernel_stack(regs, (unsigned long)addr))
213 		return *addr;
214 	else
215 		return 0;
216 }
217 
218 #define arch_has_single_step()	(1)
219 #ifdef CONFIG_X86_DEBUGCTLMSR
220 #define arch_has_block_step()	(1)
221 #else
222 #define arch_has_block_step()	(boot_cpu_data.x86 >= 6)
223 #endif
224 
225 #define ARCH_HAS_USER_SINGLE_STEP_INFO
226 
227 /*
228  * When hitting ptrace_stop(), we cannot return using SYSRET because
229  * that does not restore the full CPU state, only a minimal set.  The
230  * ptracer can change arbitrary register values, which is usually okay
231  * because the usual ptrace stops run off the signal delivery path which
232  * forces IRET; however, ptrace_event() stops happen in arbitrary places
233  * in the kernel and don't force IRET path.
234  *
235  * So force IRET path after a ptrace stop.
236  */
237 #define arch_ptrace_stop_needed(code, info)				\
238 ({									\
239 	force_iret();							\
240 	false;								\
241 })
242 
243 struct user_desc;
244 extern int do_get_thread_area(struct task_struct *p, int idx,
245 			      struct user_desc __user *info);
246 extern int do_set_thread_area(struct task_struct *p, int idx,
247 			      struct user_desc __user *info, int can_allocate);
248 
249 #endif /* !__ASSEMBLY__ */
250 #endif /* _ASM_X86_PTRACE_H */
251