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v5.9
  1/* SPDX-License-Identifier: GPL-2.0 */
  2#ifndef _ASM_X86_PTRACE_H
  3#define _ASM_X86_PTRACE_H
  4
  5#include <asm/segment.h>
  6#include <asm/page_types.h>
  7#include <uapi/asm/ptrace.h>
  8
  9#ifndef __ASSEMBLY__
 10#ifdef __i386__
 11
 12struct pt_regs {
 13	/*
 14	 * NB: 32-bit x86 CPUs are inconsistent as what happens in the
 15	 * following cases (where %seg represents a segment register):
 16	 *
 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.
 22	 *
 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.
 26	 */
 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;
 52};
 53
 54#else /* __i386__ */
 55
 56struct pt_regs {
 57/*
 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".
 60 */
 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;
 77/*
 78 * On syscall entry, this is syscall#. On CPU exception, this is error code.
 79 * On hw interrupt, it's IRQ number:
 80 */
 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 */
 89};
 90
 91#endif /* !__i386__ */
 92
 93#ifdef CONFIG_PARAVIRT
 94#include <asm/paravirt_types.h>
 95#endif
 96
 
 
 97struct cpuinfo_x86;
 98struct task_struct;
 99
100extern unsigned long profile_pc(struct pt_regs *regs);
101
102extern unsigned long
103convert_ip_to_linear(struct task_struct *child, struct pt_regs *regs);
104extern void send_sigtrap(struct pt_regs *regs, int error_code, int si_code);
105
106
107static inline unsigned long regs_return_value(struct pt_regs *regs)
108{
109	return regs->ax;
110}
111
112static inline void regs_set_return_value(struct pt_regs *regs, unsigned long rc)
113{
114	regs->ax = rc;
115}
116
117/*
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.
122 *
123 * On x86_64, vm86 mode is mercifully nonexistent, and we don't need
124 * the extra check.
125 */
126static __always_inline int user_mode(struct pt_regs *regs)
127{
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
133}
134
135static inline int v8086_mode(struct pt_regs *regs)
136{
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
142}
143
144static inline bool user_64bit_mode(struct pt_regs *regs)
145{
146#ifdef CONFIG_X86_64
147#ifndef CONFIG_PARAVIRT_XXL
148	/*
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.
151	 */
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
160}
161
162/*
163 * Determine whether the register set came from any context that is running in
164 * 64-bit mode.
165 */
166static inline bool any_64bit_mode(struct pt_regs *regs)
167{
168#ifdef CONFIG_X86_64
169	return !user_mode(regs) || user_64bit_mode(regs);
170#else
171	return false;
172#endif
173}
174
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
179
180static inline unsigned long kernel_stack_pointer(struct pt_regs *regs)
181{
182	return regs->sp;
183}
184
185static inline unsigned long instruction_pointer(struct pt_regs *regs)
186{
187	return regs->ip;
188}
189
190static inline void instruction_pointer_set(struct pt_regs *regs,
191		unsigned long val)
192{
193	regs->ip = val;
194}
195
196static inline unsigned long frame_pointer(struct pt_regs *regs)
197{
198	return regs->bp;
199}
200
201static inline unsigned long user_stack_pointer(struct pt_regs *regs)
202{
203	return regs->sp;
204}
205
206static inline void user_stack_pointer_set(struct pt_regs *regs,
207		unsigned long val)
208{
209	regs->sp = val;
210}
211
212static __always_inline bool regs_irqs_disabled(struct pt_regs *regs)
213{
214	return !(regs->flags & X86_EFLAGS_IF);
215}
216
217/* Query offset/name of register from its name/offset */
218extern int regs_query_register_offset(const char *name);
219extern const char *regs_query_register_name(unsigned int offset);
220#define MAX_REG_OFFSET (offsetof(struct pt_regs, ss))
221
222/**
223 * regs_get_register() - get register value from its offset
224 * @regs:	pt_regs from which register value is gotten.
225 * @offset:	offset number of the register.
226 *
227 * regs_get_register returns the value of a register. The @offset is the
228 * offset of the register in struct pt_regs address which specified by @regs.
229 * If @offset is bigger than MAX_REG_OFFSET, this returns 0.
230 */
231static inline unsigned long regs_get_register(struct pt_regs *regs,
232					      unsigned int offset)
233{
234	if (unlikely(offset > MAX_REG_OFFSET))
235		return 0;
236#ifdef CONFIG_X86_32
237	/* The selector fields are 16-bit. */
238	if (offset == offsetof(struct pt_regs, cs) ||
239	    offset == offsetof(struct pt_regs, ss) ||
240	    offset == offsetof(struct pt_regs, ds) ||
241	    offset == offsetof(struct pt_regs, es) ||
242	    offset == offsetof(struct pt_regs, fs) ||
243	    offset == offsetof(struct pt_regs, gs)) {
244		return *(u16 *)((unsigned long)regs + offset);
245
246	}
247#endif
248	return *(unsigned long *)((unsigned long)regs + offset);
249}
250
251/**
252 * regs_within_kernel_stack() - check the address in the stack
253 * @regs:	pt_regs which contains kernel stack pointer.
254 * @addr:	address which is checked.
255 *
256 * regs_within_kernel_stack() checks @addr is within the kernel stack page(s).
257 * If @addr is within the kernel stack, it returns true. If not, returns false.
258 */
259static inline int regs_within_kernel_stack(struct pt_regs *regs,
260					   unsigned long addr)
261{
262	return ((addr & ~(THREAD_SIZE - 1)) == (regs->sp & ~(THREAD_SIZE - 1)));
263}
264
265/**
266 * regs_get_kernel_stack_nth_addr() - get the address of the Nth entry on stack
267 * @regs:	pt_regs which contains kernel stack pointer.
268 * @n:		stack entry number.
269 *
270 * regs_get_kernel_stack_nth() returns the address of the @n th entry of the
271 * kernel stack which is specified by @regs. If the @n th entry is NOT in
272 * the kernel stack, this returns NULL.
273 */
274static inline unsigned long *regs_get_kernel_stack_nth_addr(struct pt_regs *regs, unsigned int n)
275{
276	unsigned long *addr = (unsigned long *)regs->sp;
277
278	addr += n;
279	if (regs_within_kernel_stack(regs, (unsigned long)addr))
280		return addr;
281	else
282		return NULL;
283}
284
285/* To avoid include hell, we can't include uaccess.h */
286extern long copy_from_kernel_nofault(void *dst, const void *src, size_t size);
287
288/**
289 * regs_get_kernel_stack_nth() - get Nth entry of the stack
290 * @regs:	pt_regs which contains kernel stack pointer.
291 * @n:		stack entry number.
292 *
293 * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which
294 * is specified by @regs. If the @n th entry is NOT in the kernel stack
295 * this returns 0.
296 */
297static inline unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs,
298						      unsigned int n)
299{
300	unsigned long *addr;
301	unsigned long val;
302	long ret;
303
304	addr = regs_get_kernel_stack_nth_addr(regs, n);
305	if (addr) {
306		ret = copy_from_kernel_nofault(&val, addr, sizeof(val));
307		if (!ret)
308			return val;
309	}
310	return 0;
311}
312
313/**
314 * regs_get_kernel_argument() - get Nth function argument in kernel
315 * @regs:	pt_regs of that context
316 * @n:		function argument number (start from 0)
317 *
318 * regs_get_argument() returns @n th argument of the function call.
319 * Note that this chooses most probably assignment, in some case
320 * it can be incorrect.
321 * This is expected to be called from kprobes or ftrace with regs
322 * where the top of stack is the return address.
323 */
324static inline unsigned long regs_get_kernel_argument(struct pt_regs *regs,
325						     unsigned int n)
326{
327	static const unsigned int argument_offs[] = {
328#ifdef __i386__
329		offsetof(struct pt_regs, ax),
330		offsetof(struct pt_regs, dx),
331		offsetof(struct pt_regs, cx),
332#define NR_REG_ARGUMENTS 3
333#else
334		offsetof(struct pt_regs, di),
335		offsetof(struct pt_regs, si),
336		offsetof(struct pt_regs, dx),
337		offsetof(struct pt_regs, cx),
338		offsetof(struct pt_regs, r8),
339		offsetof(struct pt_regs, r9),
340#define NR_REG_ARGUMENTS 6
341#endif
342	};
343
344	if (n >= NR_REG_ARGUMENTS) {
345		n -= NR_REG_ARGUMENTS - 1;
346		return regs_get_kernel_stack_nth(regs, n);
347	} else
348		return regs_get_register(regs, argument_offs[n]);
349}
350
351#define arch_has_single_step()	(1)
352#ifdef CONFIG_X86_DEBUGCTLMSR
353#define arch_has_block_step()	(1)
354#else
355#define arch_has_block_step()	(boot_cpu_data.x86 >= 6)
356#endif
357
358#define ARCH_HAS_USER_SINGLE_STEP_REPORT
359
360struct user_desc;
361extern int do_get_thread_area(struct task_struct *p, int idx,
362			      struct user_desc __user *info);
363extern int do_set_thread_area(struct task_struct *p, int idx,
364			      struct user_desc __user *info, int can_allocate);
365
366#ifdef CONFIG_X86_64
367# define do_set_thread_area_64(p, s, t)	do_arch_prctl_64(p, s, t)
368#else
369# define do_set_thread_area_64(p, s, t)	(0)
370#endif
371
372#endif /* !__ASSEMBLY__ */
373#endif /* _ASM_X86_PTRACE_H */
v5.14.15
  1/* SPDX-License-Identifier: GPL-2.0 */
  2#ifndef _ASM_X86_PTRACE_H
  3#define _ASM_X86_PTRACE_H
  4
  5#include <asm/segment.h>
  6#include <asm/page_types.h>
  7#include <uapi/asm/ptrace.h>
  8
  9#ifndef __ASSEMBLY__
 10#ifdef __i386__
 11
 12struct pt_regs {
 13	/*
 14	 * NB: 32-bit x86 CPUs are inconsistent as what happens in the
 15	 * following cases (where %seg represents a segment register):
 16	 *
 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.
 22	 *
 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.
 26	 */
 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	/*
 41	 * On interrupt, gs and __gsh store the vector number.  They never
 42	 * store gs any more.
 43	 */
 44	unsigned short gs;
 45	unsigned short __gsh;
 46	/* On interrupt, this is the error code. */
 47	unsigned long orig_ax;
 48	unsigned long ip;
 49	unsigned short cs;
 50	unsigned short __csh;
 51	unsigned long flags;
 52	unsigned long sp;
 53	unsigned short ss;
 54	unsigned short __ssh;
 55};
 56
 57#else /* __i386__ */
 58
 59struct pt_regs {
 60/*
 61 * C ABI says these regs are callee-preserved. They aren't saved on kernel entry
 62 * unless syscall needs a complete, fully filled "struct pt_regs".
 63 */
 64	unsigned long r15;
 65	unsigned long r14;
 66	unsigned long r13;
 67	unsigned long r12;
 68	unsigned long bp;
 69	unsigned long bx;
 70/* These regs are callee-clobbered. Always saved on kernel entry. */
 71	unsigned long r11;
 72	unsigned long r10;
 73	unsigned long r9;
 74	unsigned long r8;
 75	unsigned long ax;
 76	unsigned long cx;
 77	unsigned long dx;
 78	unsigned long si;
 79	unsigned long di;
 80/*
 81 * On syscall entry, this is syscall#. On CPU exception, this is error code.
 82 * On hw interrupt, it's IRQ number:
 83 */
 84	unsigned long orig_ax;
 85/* Return frame for iretq */
 86	unsigned long ip;
 87	unsigned long cs;
 88	unsigned long flags;
 89	unsigned long sp;
 90	unsigned long ss;
 91/* top of stack page */
 92};
 93
 94#endif /* !__i386__ */
 95
 96#ifdef CONFIG_PARAVIRT
 97#include <asm/paravirt_types.h>
 98#endif
 99
100#include <asm/proto.h>
101
102struct cpuinfo_x86;
103struct task_struct;
104
105extern unsigned long profile_pc(struct pt_regs *regs);
106
107extern unsigned long
108convert_ip_to_linear(struct task_struct *child, struct pt_regs *regs);
109extern void send_sigtrap(struct pt_regs *regs, int error_code, int si_code);
110
111
112static inline unsigned long regs_return_value(struct pt_regs *regs)
113{
114	return regs->ax;
115}
116
117static inline void regs_set_return_value(struct pt_regs *regs, unsigned long rc)
118{
119	regs->ax = rc;
120}
121
122/*
123 * user_mode(regs) determines whether a register set came from user
124 * mode.  On x86_32, this is true if V8086 mode was enabled OR if the
125 * register set was from protected mode with RPL-3 CS value.  This
126 * tricky test checks that with one comparison.
127 *
128 * On x86_64, vm86 mode is mercifully nonexistent, and we don't need
129 * the extra check.
130 */
131static __always_inline int user_mode(struct pt_regs *regs)
132{
133#ifdef CONFIG_X86_32
134	return ((regs->cs & SEGMENT_RPL_MASK) | (regs->flags & X86_VM_MASK)) >= USER_RPL;
135#else
136	return !!(regs->cs & 3);
137#endif
138}
139
140static inline int v8086_mode(struct pt_regs *regs)
141{
142#ifdef CONFIG_X86_32
143	return (regs->flags & X86_VM_MASK);
144#else
145	return 0;	/* No V86 mode support in long mode */
146#endif
147}
148
149static inline bool user_64bit_mode(struct pt_regs *regs)
150{
151#ifdef CONFIG_X86_64
152#ifndef CONFIG_PARAVIRT_XXL
153	/*
154	 * On non-paravirt systems, this is the only long mode CPL 3
155	 * selector.  We do not allow long mode selectors in the LDT.
156	 */
157	return regs->cs == __USER_CS;
158#else
159	/* Headers are too twisted for this to go in paravirt.h. */
160	return regs->cs == __USER_CS || regs->cs == pv_info.extra_user_64bit_cs;
161#endif
162#else /* !CONFIG_X86_64 */
163	return false;
164#endif
165}
166
167/*
168 * Determine whether the register set came from any context that is running in
169 * 64-bit mode.
170 */
171static inline bool any_64bit_mode(struct pt_regs *regs)
172{
173#ifdef CONFIG_X86_64
174	return !user_mode(regs) || user_64bit_mode(regs);
175#else
176	return false;
177#endif
178}
179
180#ifdef CONFIG_X86_64
181#define current_user_stack_pointer()	current_pt_regs()->sp
182#define compat_user_stack_pointer()	current_pt_regs()->sp
183
184static inline bool ip_within_syscall_gap(struct pt_regs *regs)
185{
186	bool ret = (regs->ip >= (unsigned long)entry_SYSCALL_64 &&
187		    regs->ip <  (unsigned long)entry_SYSCALL_64_safe_stack);
188
189#ifdef CONFIG_IA32_EMULATION
190	ret = ret || (regs->ip >= (unsigned long)entry_SYSCALL_compat &&
191		      regs->ip <  (unsigned long)entry_SYSCALL_compat_safe_stack);
192#endif
193
194	return ret;
195}
196#endif
197
198static inline unsigned long kernel_stack_pointer(struct pt_regs *regs)
199{
200	return regs->sp;
201}
202
203static inline unsigned long instruction_pointer(struct pt_regs *regs)
204{
205	return regs->ip;
206}
207
208static inline void instruction_pointer_set(struct pt_regs *regs,
209		unsigned long val)
210{
211	regs->ip = val;
212}
213
214static inline unsigned long frame_pointer(struct pt_regs *regs)
215{
216	return regs->bp;
217}
218
219static inline unsigned long user_stack_pointer(struct pt_regs *regs)
220{
221	return regs->sp;
222}
223
224static inline void user_stack_pointer_set(struct pt_regs *regs,
225		unsigned long val)
226{
227	regs->sp = val;
228}
229
230static __always_inline bool regs_irqs_disabled(struct pt_regs *regs)
231{
232	return !(regs->flags & X86_EFLAGS_IF);
233}
234
235/* Query offset/name of register from its name/offset */
236extern int regs_query_register_offset(const char *name);
237extern const char *regs_query_register_name(unsigned int offset);
238#define MAX_REG_OFFSET (offsetof(struct pt_regs, ss))
239
240/**
241 * regs_get_register() - get register value from its offset
242 * @regs:	pt_regs from which register value is gotten.
243 * @offset:	offset number of the register.
244 *
245 * regs_get_register returns the value of a register. The @offset is the
246 * offset of the register in struct pt_regs address which specified by @regs.
247 * If @offset is bigger than MAX_REG_OFFSET, this returns 0.
248 */
249static inline unsigned long regs_get_register(struct pt_regs *regs,
250					      unsigned int offset)
251{
252	if (unlikely(offset > MAX_REG_OFFSET))
253		return 0;
254#ifdef CONFIG_X86_32
255	/* The selector fields are 16-bit. */
256	if (offset == offsetof(struct pt_regs, cs) ||
257	    offset == offsetof(struct pt_regs, ss) ||
258	    offset == offsetof(struct pt_regs, ds) ||
259	    offset == offsetof(struct pt_regs, es) ||
260	    offset == offsetof(struct pt_regs, fs) ||
261	    offset == offsetof(struct pt_regs, gs)) {
262		return *(u16 *)((unsigned long)regs + offset);
263
264	}
265#endif
266	return *(unsigned long *)((unsigned long)regs + offset);
267}
268
269/**
270 * regs_within_kernel_stack() - check the address in the stack
271 * @regs:	pt_regs which contains kernel stack pointer.
272 * @addr:	address which is checked.
273 *
274 * regs_within_kernel_stack() checks @addr is within the kernel stack page(s).
275 * If @addr is within the kernel stack, it returns true. If not, returns false.
276 */
277static inline int regs_within_kernel_stack(struct pt_regs *regs,
278					   unsigned long addr)
279{
280	return ((addr & ~(THREAD_SIZE - 1)) == (regs->sp & ~(THREAD_SIZE - 1)));
281}
282
283/**
284 * regs_get_kernel_stack_nth_addr() - get the address of the Nth entry on stack
285 * @regs:	pt_regs which contains kernel stack pointer.
286 * @n:		stack entry number.
287 *
288 * regs_get_kernel_stack_nth() returns the address of the @n th entry of the
289 * kernel stack which is specified by @regs. If the @n th entry is NOT in
290 * the kernel stack, this returns NULL.
291 */
292static inline unsigned long *regs_get_kernel_stack_nth_addr(struct pt_regs *regs, unsigned int n)
293{
294	unsigned long *addr = (unsigned long *)regs->sp;
295
296	addr += n;
297	if (regs_within_kernel_stack(regs, (unsigned long)addr))
298		return addr;
299	else
300		return NULL;
301}
302
303/* To avoid include hell, we can't include uaccess.h */
304extern long copy_from_kernel_nofault(void *dst, const void *src, size_t size);
305
306/**
307 * regs_get_kernel_stack_nth() - get Nth entry of the stack
308 * @regs:	pt_regs which contains kernel stack pointer.
309 * @n:		stack entry number.
310 *
311 * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which
312 * is specified by @regs. If the @n th entry is NOT in the kernel stack
313 * this returns 0.
314 */
315static inline unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs,
316						      unsigned int n)
317{
318	unsigned long *addr;
319	unsigned long val;
320	long ret;
321
322	addr = regs_get_kernel_stack_nth_addr(regs, n);
323	if (addr) {
324		ret = copy_from_kernel_nofault(&val, addr, sizeof(val));
325		if (!ret)
326			return val;
327	}
328	return 0;
329}
330
331/**
332 * regs_get_kernel_argument() - get Nth function argument in kernel
333 * @regs:	pt_regs of that context
334 * @n:		function argument number (start from 0)
335 *
336 * regs_get_argument() returns @n th argument of the function call.
337 * Note that this chooses most probably assignment, in some case
338 * it can be incorrect.
339 * This is expected to be called from kprobes or ftrace with regs
340 * where the top of stack is the return address.
341 */
342static inline unsigned long regs_get_kernel_argument(struct pt_regs *regs,
343						     unsigned int n)
344{
345	static const unsigned int argument_offs[] = {
346#ifdef __i386__
347		offsetof(struct pt_regs, ax),
348		offsetof(struct pt_regs, dx),
349		offsetof(struct pt_regs, cx),
350#define NR_REG_ARGUMENTS 3
351#else
352		offsetof(struct pt_regs, di),
353		offsetof(struct pt_regs, si),
354		offsetof(struct pt_regs, dx),
355		offsetof(struct pt_regs, cx),
356		offsetof(struct pt_regs, r8),
357		offsetof(struct pt_regs, r9),
358#define NR_REG_ARGUMENTS 6
359#endif
360	};
361
362	if (n >= NR_REG_ARGUMENTS) {
363		n -= NR_REG_ARGUMENTS - 1;
364		return regs_get_kernel_stack_nth(regs, n);
365	} else
366		return regs_get_register(regs, argument_offs[n]);
367}
368
369#define arch_has_single_step()	(1)
370#ifdef CONFIG_X86_DEBUGCTLMSR
371#define arch_has_block_step()	(1)
372#else
373#define arch_has_block_step()	(boot_cpu_data.x86 >= 6)
374#endif
375
376#define ARCH_HAS_USER_SINGLE_STEP_REPORT
377
378struct user_desc;
379extern int do_get_thread_area(struct task_struct *p, int idx,
380			      struct user_desc __user *info);
381extern int do_set_thread_area(struct task_struct *p, int idx,
382			      struct user_desc __user *info, int can_allocate);
383
384#ifdef CONFIG_X86_64
385# define do_set_thread_area_64(p, s, t)	do_arch_prctl_64(p, s, t)
386#else
387# define do_set_thread_area_64(p, s, t)	(0)
388#endif
389
390#endif /* !__ASSEMBLY__ */
391#endif /* _ASM_X86_PTRACE_H */