xref: /openbmc/linux/arch/ia64/include/asm/ptrace.h (revision c6acb1e7)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3  * Copyright (C) 1998-2004 Hewlett-Packard Co
4  *	David Mosberger-Tang <davidm@hpl.hp.com>
5  *	Stephane Eranian <eranian@hpl.hp.com>
6  * Copyright (C) 2003 Intel Co
7  *	Suresh Siddha <suresh.b.siddha@intel.com>
8  *	Fenghua Yu <fenghua.yu@intel.com>
9  *	Arun Sharma <arun.sharma@intel.com>
10  *
11  * 12/07/98	S. Eranian	added pt_regs & switch_stack
12  * 12/21/98	D. Mosberger	updated to match latest code
13  *  6/17/99	D. Mosberger	added second unat member to "struct switch_stack"
14  *
15  */
16 #ifndef _ASM_IA64_PTRACE_H
17 #define _ASM_IA64_PTRACE_H
18 
19 #ifndef ASM_OFFSETS_C
20 #include <asm/asm-offsets.h>
21 #endif
22 #include <uapi/asm/ptrace.h>
23 
24 /*
25  * Base-2 logarithm of number of pages to allocate per task structure
26  * (including register backing store and memory stack):
27  */
28 #if defined(CONFIG_IA64_PAGE_SIZE_4KB)
29 # define KERNEL_STACK_SIZE_ORDER		3
30 #elif defined(CONFIG_IA64_PAGE_SIZE_8KB)
31 # define KERNEL_STACK_SIZE_ORDER		2
32 #elif defined(CONFIG_IA64_PAGE_SIZE_16KB)
33 # define KERNEL_STACK_SIZE_ORDER		1
34 #else
35 # define KERNEL_STACK_SIZE_ORDER		0
36 #endif
37 
38 #define IA64_RBS_OFFSET			((IA64_TASK_SIZE + IA64_THREAD_INFO_SIZE + 31) & ~31)
39 #define IA64_STK_OFFSET			((1 << KERNEL_STACK_SIZE_ORDER)*PAGE_SIZE)
40 
41 #define KERNEL_STACK_SIZE		IA64_STK_OFFSET
42 
43 #ifndef __ASSEMBLY__
44 
45 #include <asm/current.h>
46 #include <asm/page.h>
47 
48 /*
49  * We use the ia64_psr(regs)->ri to determine which of the three
50  * instructions in bundle (16 bytes) took the sample. Generate
51  * the canonical representation by adding to instruction pointer.
52  */
53 # define instruction_pointer(regs) ((regs)->cr_iip + ia64_psr(regs)->ri)
54 # define instruction_pointer_set(regs, val)	\
55 ({						\
56 	ia64_psr(regs)->ri = (val & 0xf);	\
57 	regs->cr_iip = (val & ~0xfULL);		\
58 })
59 
60 static inline unsigned long user_stack_pointer(struct pt_regs *regs)
61 {
62 	return regs->r12;
63 }
64 
65 static inline int is_syscall_success(struct pt_regs *regs)
66 {
67 	return regs->r10 != -1;
68 }
69 
70 static inline long regs_return_value(struct pt_regs *regs)
71 {
72 	if (is_syscall_success(regs))
73 		return regs->r8;
74 	else
75 		return -regs->r8;
76 }
77 
78 /* Conserve space in histogram by encoding slot bits in address
79  * bits 2 and 3 rather than bits 0 and 1.
80  */
81 #define profile_pc(regs)						\
82 ({									\
83 	unsigned long __ip = instruction_pointer(regs);			\
84 	(__ip & ~3UL) + ((__ip & 3UL) << 2);				\
85 })
86 
87   /* given a pointer to a task_struct, return the user's pt_regs */
88 # define task_pt_regs(t)		(((struct pt_regs *) ((char *) (t) + IA64_STK_OFFSET)) - 1)
89 # define ia64_psr(regs)			((struct ia64_psr *) &(regs)->cr_ipsr)
90 # define user_mode(regs)		(((struct ia64_psr *) &(regs)->cr_ipsr)->cpl != 0)
91 # define user_stack(task,regs)	((long) regs - (long) task == IA64_STK_OFFSET - sizeof(*regs))
92 # define fsys_mode(task,regs)					\
93   ({								\
94 	  struct task_struct *_task = (task);			\
95 	  struct pt_regs *_regs = (regs);			\
96 	  !user_mode(_regs) && user_stack(_task, _regs);	\
97   })
98 
99   /*
100    * System call handlers that, upon successful completion, need to return a negative value
101    * should call force_successful_syscall_return() right before returning.  On architectures
102    * where the syscall convention provides for a separate error flag (e.g., alpha, ia64,
103    * ppc{,64}, sparc{,64}, possibly others), this macro can be used to ensure that the error
104    * flag will not get set.  On architectures which do not support a separate error flag,
105    * the macro is a no-op and the spurious error condition needs to be filtered out by some
106    * other means (e.g., in user-level, by passing an extra argument to the syscall handler,
107    * or something along those lines).
108    *
109    * On ia64, we can clear the user's pt_regs->r8 to force a successful syscall.
110    */
111 # define force_successful_syscall_return()	(task_pt_regs(current)->r8 = 0)
112 
113   struct task_struct;			/* forward decl */
114   struct unw_frame_info;		/* forward decl */
115 
116   extern unsigned long ia64_get_user_rbs_end (struct task_struct *, struct pt_regs *,
117 					      unsigned long *);
118   extern long ia64_peek (struct task_struct *, struct switch_stack *, unsigned long,
119 			 unsigned long, long *);
120   extern long ia64_poke (struct task_struct *, struct switch_stack *, unsigned long,
121 			 unsigned long, long);
122   extern void ia64_flush_fph (struct task_struct *);
123   extern void ia64_sync_fph (struct task_struct *);
124   extern void ia64_sync_krbs(void);
125   extern long ia64_sync_user_rbs (struct task_struct *, struct switch_stack *,
126 				  unsigned long, unsigned long);
127 
128   /* get nat bits for scratch registers such that bit N==1 iff scratch register rN is a NaT */
129   extern unsigned long ia64_get_scratch_nat_bits (struct pt_regs *pt, unsigned long scratch_unat);
130   /* put nat bits for scratch registers such that scratch register rN is a NaT iff bit N==1 */
131   extern unsigned long ia64_put_scratch_nat_bits (struct pt_regs *pt, unsigned long nat);
132 
133   extern void ia64_increment_ip (struct pt_regs *pt);
134   extern void ia64_decrement_ip (struct pt_regs *pt);
135 
136   extern void ia64_ptrace_stop(void);
137   #define arch_ptrace_stop() \
138 	ia64_ptrace_stop()
139   #define arch_ptrace_stop_needed() \
140 	(!test_thread_flag(TIF_RESTORE_RSE))
141 
142   extern void ptrace_attach_sync_user_rbs (struct task_struct *);
143   #define arch_ptrace_attach(child) \
144 	ptrace_attach_sync_user_rbs(child)
145 
146   #define arch_has_single_step()  (1)
147   #define arch_has_block_step()   (1)
148 
149 #endif /* !__ASSEMBLY__ */
150 #endif /* _ASM_IA64_PTRACE_H */
151