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[linux/fpc-iii.git] / arch / x86 / include / asm / ptrace.h
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1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _ASM_X86_PTRACE_H
3 #define _ASM_X86_PTRACE_H
5 #include <asm/segment.h>
6 #include <asm/page_types.h>
7 #include <uapi/asm/ptrace.h>
9 #ifndef __ASSEMBLY__
10 #ifdef __i386__
12 struct pt_regs {
14 * NB: 32-bit x86 CPUs are inconsistent as what happens in the
15 * following cases (where %seg represents a segment register):
17 * - pushl %seg: some do a 16-bit write and leave the high
18 * bits alone
19 * - movl %seg, [mem]: some do a 16-bit write despite the movl
20 * - IDT entry: some (e.g. 486) will leave the high bits of CS
21 * and (if applicable) SS undefined.
23 * Fortunately, x86-32 doesn't read the high bits on POP or IRET,
24 * so we can just treat all of the segment registers as 16-bit
25 * values.
27 unsigned long bx;
28 unsigned long cx;
29 unsigned long dx;
30 unsigned long si;
31 unsigned long di;
32 unsigned long bp;
33 unsigned long ax;
34 unsigned short ds;
35 unsigned short __dsh;
36 unsigned short es;
37 unsigned short __esh;
38 unsigned short fs;
39 unsigned short __fsh;
40 /* On interrupt, gs and __gsh store the vector number. */
41 unsigned short gs;
42 unsigned short __gsh;
43 /* On interrupt, this is the error code. */
44 unsigned long orig_ax;
45 unsigned long ip;
46 unsigned short cs;
47 unsigned short __csh;
48 unsigned long flags;
49 unsigned long sp;
50 unsigned short ss;
51 unsigned short __ssh;
54 #else /* __i386__ */
56 struct pt_regs {
58 * C ABI says these regs are callee-preserved. They aren't saved on kernel entry
59 * unless syscall needs a complete, fully filled "struct pt_regs".
61 unsigned long r15;
62 unsigned long r14;
63 unsigned long r13;
64 unsigned long r12;
65 unsigned long bp;
66 unsigned long bx;
67 /* These regs are callee-clobbered. Always saved on kernel entry. */
68 unsigned long r11;
69 unsigned long r10;
70 unsigned long r9;
71 unsigned long r8;
72 unsigned long ax;
73 unsigned long cx;
74 unsigned long dx;
75 unsigned long si;
76 unsigned long di;
78 * On syscall entry, this is syscall#. On CPU exception, this is error code.
79 * On hw interrupt, it's IRQ number:
81 unsigned long orig_ax;
82 /* Return frame for iretq */
83 unsigned long ip;
84 unsigned long cs;
85 unsigned long flags;
86 unsigned long sp;
87 unsigned long ss;
88 /* top of stack page */
91 #endif /* !__i386__ */
93 #ifdef CONFIG_PARAVIRT
94 #include <asm/paravirt_types.h>
95 #endif
97 struct cpuinfo_x86;
98 struct task_struct;
100 extern unsigned long profile_pc(struct pt_regs *regs);
102 extern unsigned long
103 convert_ip_to_linear(struct task_struct *child, struct pt_regs *regs);
104 extern void send_sigtrap(struct pt_regs *regs, int error_code, int si_code);
107 static inline unsigned long regs_return_value(struct pt_regs *regs)
109 return regs->ax;
112 static inline void regs_set_return_value(struct pt_regs *regs, unsigned long rc)
114 regs->ax = rc;
118 * user_mode(regs) determines whether a register set came from user
119 * mode. On x86_32, this is true if V8086 mode was enabled OR if the
120 * register set was from protected mode with RPL-3 CS value. This
121 * tricky test checks that with one comparison.
123 * On x86_64, vm86 mode is mercifully nonexistent, and we don't need
124 * the extra check.
126 static inline int user_mode(struct pt_regs *regs)
128 #ifdef CONFIG_X86_32
129 return ((regs->cs & SEGMENT_RPL_MASK) | (regs->flags & X86_VM_MASK)) >= USER_RPL;
130 #else
131 return !!(regs->cs & 3);
132 #endif
135 static inline int v8086_mode(struct pt_regs *regs)
137 #ifdef CONFIG_X86_32
138 return (regs->flags & X86_VM_MASK);
139 #else
140 return 0; /* No V86 mode support in long mode */
141 #endif
144 static inline bool user_64bit_mode(struct pt_regs *regs)
146 #ifdef CONFIG_X86_64
147 #ifndef CONFIG_PARAVIRT_XXL
149 * On non-paravirt systems, this is the only long mode CPL 3
150 * selector. We do not allow long mode selectors in the LDT.
152 return regs->cs == __USER_CS;
153 #else
154 /* Headers are too twisted for this to go in paravirt.h. */
155 return regs->cs == __USER_CS || regs->cs == pv_info.extra_user_64bit_cs;
156 #endif
157 #else /* !CONFIG_X86_64 */
158 return false;
159 #endif
163 * Determine whether the register set came from any context that is running in
164 * 64-bit mode.
166 static inline bool any_64bit_mode(struct pt_regs *regs)
168 #ifdef CONFIG_X86_64
169 return !user_mode(regs) || user_64bit_mode(regs);
170 #else
171 return false;
172 #endif
175 #ifdef CONFIG_X86_64
176 #define current_user_stack_pointer() current_pt_regs()->sp
177 #define compat_user_stack_pointer() current_pt_regs()->sp
178 #endif
180 static inline unsigned long kernel_stack_pointer(struct pt_regs *regs)
182 return regs->sp;
185 static inline unsigned long instruction_pointer(struct pt_regs *regs)
187 return regs->ip;
190 static inline void instruction_pointer_set(struct pt_regs *regs,
191 unsigned long val)
193 regs->ip = val;
196 static inline unsigned long frame_pointer(struct pt_regs *regs)
198 return regs->bp;
201 static inline unsigned long user_stack_pointer(struct pt_regs *regs)
203 return regs->sp;
206 static inline void user_stack_pointer_set(struct pt_regs *regs,
207 unsigned long val)
209 regs->sp = val;
212 /* Query offset/name of register from its name/offset */
213 extern int regs_query_register_offset(const char *name);
214 extern const char *regs_query_register_name(unsigned int offset);
215 #define MAX_REG_OFFSET (offsetof(struct pt_regs, ss))
218 * regs_get_register() - get register value from its offset
219 * @regs: pt_regs from which register value is gotten.
220 * @offset: offset number of the register.
222 * regs_get_register returns the value of a register. The @offset is the
223 * offset of the register in struct pt_regs address which specified by @regs.
224 * If @offset is bigger than MAX_REG_OFFSET, this returns 0.
226 static inline unsigned long regs_get_register(struct pt_regs *regs,
227 unsigned int offset)
229 if (unlikely(offset > MAX_REG_OFFSET))
230 return 0;
231 #ifdef CONFIG_X86_32
232 /* The selector fields are 16-bit. */
233 if (offset == offsetof(struct pt_regs, cs) ||
234 offset == offsetof(struct pt_regs, ss) ||
235 offset == offsetof(struct pt_regs, ds) ||
236 offset == offsetof(struct pt_regs, es) ||
237 offset == offsetof(struct pt_regs, fs) ||
238 offset == offsetof(struct pt_regs, gs)) {
239 return *(u16 *)((unsigned long)regs + offset);
242 #endif
243 return *(unsigned long *)((unsigned long)regs + offset);
247 * regs_within_kernel_stack() - check the address in the stack
248 * @regs: pt_regs which contains kernel stack pointer.
249 * @addr: address which is checked.
251 * regs_within_kernel_stack() checks @addr is within the kernel stack page(s).
252 * If @addr is within the kernel stack, it returns true. If not, returns false.
254 static inline int regs_within_kernel_stack(struct pt_regs *regs,
255 unsigned long addr)
257 return ((addr & ~(THREAD_SIZE - 1)) == (regs->sp & ~(THREAD_SIZE - 1)));
261 * regs_get_kernel_stack_nth_addr() - get the address of the Nth entry on stack
262 * @regs: pt_regs which contains kernel stack pointer.
263 * @n: stack entry number.
265 * regs_get_kernel_stack_nth() returns the address of the @n th entry of the
266 * kernel stack which is specified by @regs. If the @n th entry is NOT in
267 * the kernel stack, this returns NULL.
269 static inline unsigned long *regs_get_kernel_stack_nth_addr(struct pt_regs *regs, unsigned int n)
271 unsigned long *addr = (unsigned long *)regs->sp;
273 addr += n;
274 if (regs_within_kernel_stack(regs, (unsigned long)addr))
275 return addr;
276 else
277 return NULL;
280 /* To avoid include hell, we can't include uaccess.h */
281 extern long probe_kernel_read(void *dst, const void *src, size_t size);
284 * regs_get_kernel_stack_nth() - get Nth entry of the stack
285 * @regs: pt_regs which contains kernel stack pointer.
286 * @n: stack entry number.
288 * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which
289 * is specified by @regs. If the @n th entry is NOT in the kernel stack
290 * this returns 0.
292 static inline unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs,
293 unsigned int n)
295 unsigned long *addr;
296 unsigned long val;
297 long ret;
299 addr = regs_get_kernel_stack_nth_addr(regs, n);
300 if (addr) {
301 ret = probe_kernel_read(&val, addr, sizeof(val));
302 if (!ret)
303 return val;
305 return 0;
309 * regs_get_kernel_argument() - get Nth function argument in kernel
310 * @regs: pt_regs of that context
311 * @n: function argument number (start from 0)
313 * regs_get_argument() returns @n th argument of the function call.
314 * Note that this chooses most probably assignment, in some case
315 * it can be incorrect.
316 * This is expected to be called from kprobes or ftrace with regs
317 * where the top of stack is the return address.
319 static inline unsigned long regs_get_kernel_argument(struct pt_regs *regs,
320 unsigned int n)
322 static const unsigned int argument_offs[] = {
323 #ifdef __i386__
324 offsetof(struct pt_regs, ax),
325 offsetof(struct pt_regs, cx),
326 offsetof(struct pt_regs, dx),
327 #define NR_REG_ARGUMENTS 3
328 #else
329 offsetof(struct pt_regs, di),
330 offsetof(struct pt_regs, si),
331 offsetof(struct pt_regs, dx),
332 offsetof(struct pt_regs, cx),
333 offsetof(struct pt_regs, r8),
334 offsetof(struct pt_regs, r9),
335 #define NR_REG_ARGUMENTS 6
336 #endif
339 if (n >= NR_REG_ARGUMENTS) {
340 n -= NR_REG_ARGUMENTS - 1;
341 return regs_get_kernel_stack_nth(regs, n);
342 } else
343 return regs_get_register(regs, argument_offs[n]);
346 #define arch_has_single_step() (1)
347 #ifdef CONFIG_X86_DEBUGCTLMSR
348 #define arch_has_block_step() (1)
349 #else
350 #define arch_has_block_step() (boot_cpu_data.x86 >= 6)
351 #endif
353 #define ARCH_HAS_USER_SINGLE_STEP_REPORT
355 struct user_desc;
356 extern int do_get_thread_area(struct task_struct *p, int idx,
357 struct user_desc __user *info);
358 extern int do_set_thread_area(struct task_struct *p, int idx,
359 struct user_desc __user *info, int can_allocate);
361 #ifdef CONFIG_X86_64
362 # define do_set_thread_area_64(p, s, t) do_arch_prctl_64(p, s, t)
363 #else
364 # define do_set_thread_area_64(p, s, t) (0)
365 #endif
367 #endif /* !__ASSEMBLY__ */
368 #endif /* _ASM_X86_PTRACE_H */