xref: /openbmc/linux/arch/alpha/include/asm/ptrace.h (revision 95e9fd10)
1 #ifndef _ASMAXP_PTRACE_H
2 #define _ASMAXP_PTRACE_H
3 
4 
5 /*
6  * This struct defines the way the registers are stored on the
7  * kernel stack during a system call or other kernel entry
8  *
9  * NOTE! I want to minimize the overhead of system calls, so this
10  * struct has as little information as possible.  I does not have
11  *
12  *  - floating point regs: the kernel doesn't change those
13  *  - r9-15: saved by the C compiler
14  *
15  * This makes "fork()" and "exec()" a bit more complex, but should
16  * give us low system call latency.
17  */
18 
19 struct pt_regs {
20 	unsigned long r0;
21 	unsigned long r1;
22 	unsigned long r2;
23 	unsigned long r3;
24 	unsigned long r4;
25 	unsigned long r5;
26 	unsigned long r6;
27 	unsigned long r7;
28 	unsigned long r8;
29 	unsigned long r19;
30 	unsigned long r20;
31 	unsigned long r21;
32 	unsigned long r22;
33 	unsigned long r23;
34 	unsigned long r24;
35 	unsigned long r25;
36 	unsigned long r26;
37 	unsigned long r27;
38 	unsigned long r28;
39 	unsigned long hae;
40 /* JRP - These are the values provided to a0-a2 by PALcode */
41 	unsigned long trap_a0;
42 	unsigned long trap_a1;
43 	unsigned long trap_a2;
44 /* These are saved by PAL-code: */
45 	unsigned long ps;
46 	unsigned long pc;
47 	unsigned long gp;
48 	unsigned long r16;
49 	unsigned long r17;
50 	unsigned long r18;
51 };
52 
53 /*
54  * This is the extended stack used by signal handlers and the context
55  * switcher: it's pushed after the normal "struct pt_regs".
56  */
57 struct switch_stack {
58 	unsigned long r9;
59 	unsigned long r10;
60 	unsigned long r11;
61 	unsigned long r12;
62 	unsigned long r13;
63 	unsigned long r14;
64 	unsigned long r15;
65 	unsigned long r26;
66 	unsigned long fp[32];	/* fp[31] is fpcr */
67 };
68 
69 #ifdef __KERNEL__
70 
71 #define arch_has_single_step()		(1)
72 #define user_mode(regs) (((regs)->ps & 8) != 0)
73 #define instruction_pointer(regs) ((regs)->pc)
74 #define profile_pc(regs) instruction_pointer(regs)
75 
76 #define task_pt_regs(task) \
77   ((struct pt_regs *) (task_stack_page(task) + 2*PAGE_SIZE) - 1)
78 
79 #define current_pt_regs() \
80   ((struct pt_regs *) ((char *)current_thread_info() + 2*PAGE_SIZE) - 1)
81 
82 #define force_successful_syscall_return() (current_pt_regs()->r0 = 0)
83 
84 #endif
85 
86 #endif
87