1 /* SPDX-License-Identifier: GPL-2.0 */ <<
2 /* 1 /*
3 * Copyright (C) 2000 Anton Blanchard (anton@l 2 * Copyright (C) 2000 Anton Blanchard (anton@linuxcare.com)
4 * 3 *
5 * This file implements mcount(), which is use 4 * This file implements mcount(), which is used to collect profiling data.
6 * This can also be tweaked for kernel stack o 5 * This can also be tweaked for kernel stack overflow detection.
7 */ 6 */
8 7
9 #include <linux/export.h> <<
10 #include <linux/linkage.h> 8 #include <linux/linkage.h>
11 9
>> 10 #include <asm/ptrace.h>
>> 11 #include <asm/thread_info.h>
>> 12
12 /* 13 /*
13 * This is the main variant and is called by C 14 * This is the main variant and is called by C code. GCC's -pg option
14 * automatically instruments every C function 15 * automatically instruments every C function with a call to this.
15 */ 16 */
16 17
>> 18 #ifdef CONFIG_STACK_DEBUG
>> 19
>> 20 #define OVSTACKSIZE 4096 /* lets hope this is enough */
>> 21
>> 22 .data
>> 23 .align 8
>> 24 panicstring:
>> 25 .asciz "Stack overflow\n"
>> 26 .align 8
>> 27 ovstack:
>> 28 .skip OVSTACKSIZE
>> 29 #endif
17 .text 30 .text
18 .align 32 31 .align 32
19 .globl _mcount 32 .globl _mcount
20 .type _mcount,#function 33 .type _mcount,#function
21 EXPORT_SYMBOL(_mcount) <<
22 .globl mcount 34 .globl mcount
23 .type mcount,#function 35 .type mcount,#function
24 _mcount: 36 _mcount:
25 mcount: 37 mcount:
>> 38 #ifdef CONFIG_STACK_DEBUG
>> 39 /*
>> 40 * Check whether %sp is dangerously low.
>> 41 */
>> 42 ldub [%g6 + TI_FPDEPTH], %g1
>> 43 srl %g1, 1, %g3
>> 44 add %g3, 1, %g3
>> 45 sllx %g3, 8, %g3 ! each fpregs frame is 256b
>> 46 add %g3, 192, %g3
>> 47 add %g6, %g3, %g3 ! where does task_struct+frame end?
>> 48 sub %g3, STACK_BIAS, %g3
>> 49 cmp %sp, %g3
>> 50 bg,pt %xcc, 1f
>> 51 nop
>> 52 lduh [%g6 + TI_CPU], %g1
>> 53 sethi %hi(hardirq_stack), %g3
>> 54 or %g3, %lo(hardirq_stack), %g3
>> 55 sllx %g1, 3, %g1
>> 56 ldx [%g3 + %g1], %g7
>> 57 sub %g7, STACK_BIAS, %g7
>> 58 cmp %sp, %g7
>> 59 bleu,pt %xcc, 2f
>> 60 sethi %hi(THREAD_SIZE), %g3
>> 61 add %g7, %g3, %g7
>> 62 cmp %sp, %g7
>> 63 blu,pn %xcc, 1f
>> 64 2: sethi %hi(softirq_stack), %g3
>> 65 or %g3, %lo(softirq_stack), %g3
>> 66 ldx [%g3 + %g1], %g7
>> 67 sub %g7, STACK_BIAS, %g7
>> 68 cmp %sp, %g7
>> 69 bleu,pt %xcc, 3f
>> 70 sethi %hi(THREAD_SIZE), %g3
>> 71 add %g7, %g3, %g7
>> 72 cmp %sp, %g7
>> 73 blu,pn %xcc, 1f
>> 74 nop
>> 75 /* If we are already on ovstack, don't hop onto it
>> 76 * again, we are already trying to output the stack overflow
>> 77 * message.
>> 78 */
>> 79 3: sethi %hi(ovstack), %g7 ! cant move to panic stack fast enough
>> 80 or %g7, %lo(ovstack), %g7
>> 81 add %g7, OVSTACKSIZE, %g3
>> 82 sub %g3, STACK_BIAS + 192, %g3
>> 83 sub %g7, STACK_BIAS, %g7
>> 84 cmp %sp, %g7
>> 85 blu,pn %xcc, 2f
>> 86 cmp %sp, %g3
>> 87 bleu,pn %xcc, 1f
>> 88 nop
>> 89 2: mov %g3, %sp
>> 90 sethi %hi(panicstring), %g3
>> 91 call prom_printf
>> 92 or %g3, %lo(panicstring), %o0
>> 93 call prom_halt
>> 94 nop
>> 95 1:
>> 96 #endif
26 #ifdef CONFIG_FUNCTION_TRACER 97 #ifdef CONFIG_FUNCTION_TRACER
27 #ifdef CONFIG_DYNAMIC_FTRACE 98 #ifdef CONFIG_DYNAMIC_FTRACE
28 /* Do nothing, the retl/nop below is a !! 99 mov %o7, %o0
>> 100 .globl mcount_call
>> 101 mcount_call:
>> 102 call ftrace_stub
>> 103 mov %o0, %o7
29 #else 104 #else
30 sethi %hi(ftrace_trace_funct 105 sethi %hi(ftrace_trace_function), %g1
31 sethi %hi(ftrace_stub), %g2 106 sethi %hi(ftrace_stub), %g2
32 ldx [%g1 + %lo(ftrace_trac 107 ldx [%g1 + %lo(ftrace_trace_function)], %g1
33 or %g2, %lo(ftrace_stub), 108 or %g2, %lo(ftrace_stub), %g2
34 cmp %g1, %g2 109 cmp %g1, %g2
35 be,pn %icc, 1f 110 be,pn %icc, 1f
36 mov %i7, %g3 !! 111 mov %i7, %o1
37 save %sp, -176, %sp !! 112 jmpl %g1, %g0
38 mov %g3, %o1 !! 113 mov %o7, %o0
39 jmpl %g1, %o7 <<
40 mov %i7, %o0 <<
41 ret <<
42 restore <<
43 /* not reached */ 114 /* not reached */
44 1: 115 1:
45 #ifdef CONFIG_FUNCTION_GRAPH_TRACER <<
46 sethi %hi(ftrace_graph_retur <<
47 ldx [%g1 + %lo(ftrace_grap <<
48 cmp %g2, %g3 <<
49 bne,pn %xcc, 5f <<
50 sethi %hi(ftrace_graph_entry <<
51 sethi %hi(ftrace_graph_entry <<
52 or %g2, %lo(ftrace_graph_ <<
53 ldx [%g1 + %lo(ftrace_grap <<
54 cmp %g1, %g2 <<
55 be,pt %xcc, 2f <<
56 nop <<
57 5: mov %i7, %g2 <<
58 mov %fp, %g3 <<
59 save %sp, -176, %sp <<
60 mov %g2, %l0 <<
61 ba,pt %xcc, ftrace_graph_cal <<
62 mov %g3, %l1 <<
63 #endif <<
64 2: <<
65 #endif 116 #endif
66 #endif 117 #endif
67 retl 118 retl
68 nop 119 nop
69 .size _mcount,.-_mcount 120 .size _mcount,.-_mcount
70 .size mcount,.-mcount 121 .size mcount,.-mcount
71 122
72 #ifdef CONFIG_FUNCTION_TRACER 123 #ifdef CONFIG_FUNCTION_TRACER
73 .globl ftrace_stub 124 .globl ftrace_stub
74 .type ftrace_stub,#function 125 .type ftrace_stub,#function
75 ftrace_stub: 126 ftrace_stub:
76 retl 127 retl
77 nop 128 nop
78 .size ftrace_stub,.-ftrace_s 129 .size ftrace_stub,.-ftrace_stub
79 #ifdef CONFIG_DYNAMIC_FTRACE 130 #ifdef CONFIG_DYNAMIC_FTRACE
80 .globl ftrace_caller 131 .globl ftrace_caller
81 .type ftrace_caller,#functio 132 .type ftrace_caller,#function
82 ftrace_caller: 133 ftrace_caller:
83 mov %i7, %g2 !! 134 mov %i7, %o1
84 mov %fp, %g3 !! 135 mov %o7, %o0
85 save %sp, -176, %sp <<
86 mov %g2, %o1 <<
87 mov %g2, %l0 <<
88 mov %g3, %l1 <<
89 .globl ftrace_call 136 .globl ftrace_call
90 ftrace_call: 137 ftrace_call:
91 call ftrace_stub 138 call ftrace_stub
92 mov %i7, %o0 !! 139 mov %o0, %o7
93 #ifdef CONFIG_FUNCTION_GRAPH_TRACER !! 140 retl
94 .globl ftrace_graph_call <<
95 ftrace_graph_call: <<
96 call ftrace_stub <<
97 nop 141 nop
98 #endif <<
99 ret <<
100 restore <<
101 #ifdef CONFIG_FUNCTION_GRAPH_TRACER <<
102 .size ftrace_graph_call,.-ft <<
103 #endif <<
104 .size ftrace_call,.-ftrace_c <<
105 .size ftrace_caller,.-ftrace 142 .size ftrace_caller,.-ftrace_caller
106 #endif 143 #endif
107 #endif <<
108 <<
109 #ifdef CONFIG_FUNCTION_GRAPH_TRACER <<
110 ENTRY(ftrace_graph_caller) <<
111 mov %l0, %o0 <<
112 mov %i7, %o1 <<
113 call prepare_ftrace_return <<
114 mov %l1, %o2 <<
115 ret <<
116 restore %o0, -8, %i7 <<
117 END(ftrace_graph_caller) <<
118 <<
119 ENTRY(return_to_handler) <<
120 save %sp, -176, %sp <<
121 call ftrace_return_to_handl <<
122 mov %fp, %o0 <<
123 jmpl %o0 + 8, %g0 <<
124 restore <<
125 END(return_to_handler) <<
126 #endif 144 #endif
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