xref: /openbmc/linux/arch/x86/include/asm/ptrace.h (revision 99b7e93c)
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 extern unsigned long syscall_trace_enter_phase1(struct pt_regs *, u32 arch);
87 extern long syscall_trace_enter_phase2(struct pt_regs *, u32 arch,
88 				       unsigned long phase1_result);
89 
90 extern long syscall_trace_enter(struct pt_regs *);
91 extern void syscall_trace_leave(struct pt_regs *);
92 
93 static inline unsigned long regs_return_value(struct pt_regs *regs)
94 {
95 	return regs->ax;
96 }
97 
98 /*
99  * user_mode(regs) determines whether a register set came from user
100  * mode.  On x86_32, this is true if V8086 mode was enabled OR if the
101  * register set was from protected mode with RPL-3 CS value.  This
102  * tricky test checks that with one comparison.
103  *
104  * On x86_64, vm86 mode is mercifully nonexistent, and we don't need
105  * the extra check.
106  */
107 static inline int user_mode(struct pt_regs *regs)
108 {
109 #ifdef CONFIG_X86_32
110 	return (regs->cs & SEGMENT_RPL_MASK) == USER_RPL;
111 #else
112 	return !!(regs->cs & 3);
113 #endif
114 }
115 
116 static inline int v8086_mode(struct pt_regs *regs)
117 {
118 #ifdef CONFIG_X86_32
119 	return (regs->flags & X86_VM_MASK);
120 #else
121 	return 0;	/* No V86 mode support in long mode */
122 #endif
123 }
124 
125 #ifdef CONFIG_X86_64
126 static inline bool user_64bit_mode(struct pt_regs *regs)
127 {
128 #ifndef CONFIG_PARAVIRT
129 	/*
130 	 * On non-paravirt systems, this is the only long mode CPL 3
131 	 * selector.  We do not allow long mode selectors in the LDT.
132 	 */
133 	return regs->cs == __USER_CS;
134 #else
135 	/* Headers are too twisted for this to go in paravirt.h. */
136 	return regs->cs == __USER_CS || regs->cs == pv_info.extra_user_64bit_cs;
137 #endif
138 }
139 
140 #define current_user_stack_pointer()	current_pt_regs()->sp
141 #define compat_user_stack_pointer()	current_pt_regs()->sp
142 #endif
143 
144 #ifdef CONFIG_X86_32
145 extern unsigned long kernel_stack_pointer(struct pt_regs *regs);
146 #else
147 static inline unsigned long kernel_stack_pointer(struct pt_regs *regs)
148 {
149 	return regs->sp;
150 }
151 #endif
152 
153 #define GET_IP(regs) ((regs)->ip)
154 #define GET_FP(regs) ((regs)->bp)
155 #define GET_USP(regs) ((regs)->sp)
156 
157 #include <asm-generic/ptrace.h>
158 
159 /* Query offset/name of register from its name/offset */
160 extern int regs_query_register_offset(const char *name);
161 extern const char *regs_query_register_name(unsigned int offset);
162 #define MAX_REG_OFFSET (offsetof(struct pt_regs, ss))
163 
164 /**
165  * regs_get_register() - get register value from its offset
166  * @regs:	pt_regs from which register value is gotten.
167  * @offset:	offset number of the register.
168  *
169  * regs_get_register returns the value of a register. The @offset is the
170  * offset of the register in struct pt_regs address which specified by @regs.
171  * If @offset is bigger than MAX_REG_OFFSET, this returns 0.
172  */
173 static inline unsigned long regs_get_register(struct pt_regs *regs,
174 					      unsigned int offset)
175 {
176 	if (unlikely(offset > MAX_REG_OFFSET))
177 		return 0;
178 #ifdef CONFIG_X86_32
179 	/*
180 	 * Traps from the kernel do not save sp and ss.
181 	 * Use the helper function to retrieve sp.
182 	 */
183 	if (offset == offsetof(struct pt_regs, sp) &&
184 	    regs->cs == __KERNEL_CS)
185 		return kernel_stack_pointer(regs);
186 #endif
187 	return *(unsigned long *)((unsigned long)regs + offset);
188 }
189 
190 /**
191  * regs_within_kernel_stack() - check the address in the stack
192  * @regs:	pt_regs which contains kernel stack pointer.
193  * @addr:	address which is checked.
194  *
195  * regs_within_kernel_stack() checks @addr is within the kernel stack page(s).
196  * If @addr is within the kernel stack, it returns true. If not, returns false.
197  */
198 static inline int regs_within_kernel_stack(struct pt_regs *regs,
199 					   unsigned long addr)
200 {
201 	return ((addr & ~(THREAD_SIZE - 1))  ==
202 		(kernel_stack_pointer(regs) & ~(THREAD_SIZE - 1)));
203 }
204 
205 /**
206  * regs_get_kernel_stack_nth() - get Nth entry of the stack
207  * @regs:	pt_regs which contains kernel stack pointer.
208  * @n:		stack entry number.
209  *
210  * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which
211  * is specified by @regs. If the @n th entry is NOT in the kernel stack,
212  * this returns 0.
213  */
214 static inline unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs,
215 						      unsigned int n)
216 {
217 	unsigned long *addr = (unsigned long *)kernel_stack_pointer(regs);
218 	addr += n;
219 	if (regs_within_kernel_stack(regs, (unsigned long)addr))
220 		return *addr;
221 	else
222 		return 0;
223 }
224 
225 #define arch_has_single_step()	(1)
226 #ifdef CONFIG_X86_DEBUGCTLMSR
227 #define arch_has_block_step()	(1)
228 #else
229 #define arch_has_block_step()	(boot_cpu_data.x86 >= 6)
230 #endif
231 
232 #define ARCH_HAS_USER_SINGLE_STEP_INFO
233 
234 /*
235  * When hitting ptrace_stop(), we cannot return using SYSRET because
236  * that does not restore the full CPU state, only a minimal set.  The
237  * ptracer can change arbitrary register values, which is usually okay
238  * because the usual ptrace stops run off the signal delivery path which
239  * forces IRET; however, ptrace_event() stops happen in arbitrary places
240  * in the kernel and don't force IRET path.
241  *
242  * So force IRET path after a ptrace stop.
243  */
244 #define arch_ptrace_stop_needed(code, info)				\
245 ({									\
246 	force_iret();							\
247 	false;								\
248 })
249 
250 struct user_desc;
251 extern int do_get_thread_area(struct task_struct *p, int idx,
252 			      struct user_desc __user *info);
253 extern int do_set_thread_area(struct task_struct *p, int idx,
254 			      struct user_desc __user *info, int can_allocate);
255 
256 #endif /* !__ASSEMBLY__ */
257 #endif /* _ASM_X86_PTRACE_H */
258