1 // SPDX-License-Identifier: GPL-2.0 1 // SPDX-License-Identifier: GPL-2.0
2 #include <linux/spinlock.h> 2 #include <linux/spinlock.h>
3 #include <linux/hardirq.h> 3 #include <linux/hardirq.h>
4 #include <linux/ftrace.h> 4 #include <linux/ftrace.h>
5 #include <linux/percpu.h> 5 #include <linux/percpu.h>
6 #include <linux/init.h> 6 #include <linux/init.h>
7 #include <linux/list.h> 7 #include <linux/list.h>
8 #include <trace/syscall.h> 8 #include <trace/syscall.h>
9 9
10 #include <asm/ftrace.h> 10 #include <asm/ftrace.h>
11 11
12 #ifdef CONFIG_DYNAMIC_FTRACE 12 #ifdef CONFIG_DYNAMIC_FTRACE
13 static const u32 ftrace_nop = 0x01000000; 13 static const u32 ftrace_nop = 0x01000000;
14 14
15 static u32 ftrace_call_replace(unsigned long i 15 static u32 ftrace_call_replace(unsigned long ip, unsigned long addr)
16 { 16 {
17 u32 call; 17 u32 call;
18 s32 off; 18 s32 off;
19 19
20 off = ((s32)addr - (s32)ip); 20 off = ((s32)addr - (s32)ip);
21 call = 0x40000000 | ((u32)off >> 2); 21 call = 0x40000000 | ((u32)off >> 2);
22 22
23 return call; 23 return call;
24 } 24 }
25 25
26 static int ftrace_modify_code(unsigned long ip 26 static int ftrace_modify_code(unsigned long ip, u32 old, u32 new)
27 { 27 {
28 u32 replaced; 28 u32 replaced;
29 int faulted; 29 int faulted;
30 30
31 __asm__ __volatile__( 31 __asm__ __volatile__(
32 "1: cas [%[ip]], %[old], %[new 32 "1: cas [%[ip]], %[old], %[new]\n"
33 " flush %[ip]\n" 33 " flush %[ip]\n"
34 " mov 0, %[faulted]\n" 34 " mov 0, %[faulted]\n"
35 "2:\n" 35 "2:\n"
36 " .section .fixup,#alloc,#execin 36 " .section .fixup,#alloc,#execinstr\n"
37 " .align 4\n" 37 " .align 4\n"
38 "3: sethi %%hi(2b), %[faulted]\n 38 "3: sethi %%hi(2b), %[faulted]\n"
39 " jmpl %[faulted] + %%lo(2b), 39 " jmpl %[faulted] + %%lo(2b), %%g0\n"
40 " mov 1, %[faulted]\n" 40 " mov 1, %[faulted]\n"
41 " .previous\n" 41 " .previous\n"
42 " .section __ex_table,\"a\"\n" 42 " .section __ex_table,\"a\"\n"
43 " .align 4\n" 43 " .align 4\n"
44 " .word 1b, 3b\n" 44 " .word 1b, 3b\n"
45 " .previous\n" 45 " .previous\n"
46 : "=r" (replaced), [faulted] "=r" (fau 46 : "=r" (replaced), [faulted] "=r" (faulted)
47 : [new] "" (new), [old] "r" (old), [ip 47 : [new] "" (new), [old] "r" (old), [ip] "r" (ip)
48 : "memory"); 48 : "memory");
49 49
50 if (replaced != old && replaced != new 50 if (replaced != old && replaced != new)
51 faulted = 2; 51 faulted = 2;
52 52
53 return faulted; 53 return faulted;
54 } 54 }
55 55
56 int ftrace_make_nop(struct module *mod, struct 56 int ftrace_make_nop(struct module *mod, struct dyn_ftrace *rec, unsigned long addr)
57 { 57 {
58 unsigned long ip = rec->ip; 58 unsigned long ip = rec->ip;
59 u32 old, new; 59 u32 old, new;
60 60
61 old = ftrace_call_replace(ip, addr); 61 old = ftrace_call_replace(ip, addr);
62 new = ftrace_nop; 62 new = ftrace_nop;
63 return ftrace_modify_code(ip, old, new 63 return ftrace_modify_code(ip, old, new);
64 } 64 }
65 65
66 int ftrace_make_call(struct dyn_ftrace *rec, u 66 int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr)
67 { 67 {
68 unsigned long ip = rec->ip; 68 unsigned long ip = rec->ip;
69 u32 old, new; 69 u32 old, new;
70 70
71 old = ftrace_nop; 71 old = ftrace_nop;
72 new = ftrace_call_replace(ip, addr); 72 new = ftrace_call_replace(ip, addr);
73 return ftrace_modify_code(ip, old, new 73 return ftrace_modify_code(ip, old, new);
74 } 74 }
75 75
76 int ftrace_update_ftrace_func(ftrace_func_t fu 76 int ftrace_update_ftrace_func(ftrace_func_t func)
77 { 77 {
78 unsigned long ip = (unsigned long)(&ft 78 unsigned long ip = (unsigned long)(&ftrace_call);
79 u32 old, new; 79 u32 old, new;
80 80
81 old = *(u32 *) &ftrace_call; 81 old = *(u32 *) &ftrace_call;
82 new = ftrace_call_replace(ip, (unsigne 82 new = ftrace_call_replace(ip, (unsigned long)func);
83 return ftrace_modify_code(ip, old, new 83 return ftrace_modify_code(ip, old, new);
84 } 84 }
85 #endif 85 #endif
86 86
87 #ifdef CONFIG_FUNCTION_GRAPH_TRACER 87 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
88 88
89 #ifdef CONFIG_DYNAMIC_FTRACE 89 #ifdef CONFIG_DYNAMIC_FTRACE
90 extern void ftrace_graph_call(void); 90 extern void ftrace_graph_call(void);
91 91
92 int ftrace_enable_ftrace_graph_caller(void) 92 int ftrace_enable_ftrace_graph_caller(void)
93 { 93 {
94 unsigned long ip = (unsigned long)(&ft 94 unsigned long ip = (unsigned long)(&ftrace_graph_call);
95 u32 old, new; 95 u32 old, new;
96 96
97 old = *(u32 *) &ftrace_graph_call; 97 old = *(u32 *) &ftrace_graph_call;
98 new = ftrace_call_replace(ip, (unsigne 98 new = ftrace_call_replace(ip, (unsigned long) &ftrace_graph_caller);
99 return ftrace_modify_code(ip, old, new 99 return ftrace_modify_code(ip, old, new);
100 } 100 }
101 101
102 int ftrace_disable_ftrace_graph_caller(void) 102 int ftrace_disable_ftrace_graph_caller(void)
103 { 103 {
104 unsigned long ip = (unsigned long)(&ft 104 unsigned long ip = (unsigned long)(&ftrace_graph_call);
105 u32 old, new; 105 u32 old, new;
106 106
107 old = *(u32 *) &ftrace_graph_call; 107 old = *(u32 *) &ftrace_graph_call;
108 new = ftrace_call_replace(ip, (unsigne 108 new = ftrace_call_replace(ip, (unsigned long) &ftrace_stub);
109 109
110 return ftrace_modify_code(ip, old, new 110 return ftrace_modify_code(ip, old, new);
111 } 111 }
112 112
113 #endif /* !CONFIG_DYNAMIC_FTRACE */ 113 #endif /* !CONFIG_DYNAMIC_FTRACE */
114 114
115 /* 115 /*
116 * Hook the return address and push it in the 116 * Hook the return address and push it in the stack of return addrs
117 * in current thread info. 117 * in current thread info.
118 */ 118 */
119 unsigned long prepare_ftrace_return(unsigned l 119 unsigned long prepare_ftrace_return(unsigned long parent,
120 unsigned l 120 unsigned long self_addr,
121 unsigned l 121 unsigned long frame_pointer)
122 { 122 {
123 unsigned long return_hooker = (unsigne 123 unsigned long return_hooker = (unsigned long) &return_to_handler;
124 124
125 if (unlikely(atomic_read(¤t->tra 125 if (unlikely(atomic_read(¤t->tracing_graph_pause)))
126 return parent + 8UL; 126 return parent + 8UL;
127 127
128 if (function_graph_enter(parent, self_ 128 if (function_graph_enter(parent, self_addr, frame_pointer, NULL))
129 return parent + 8UL; 129 return parent + 8UL;
130 130
131 return return_hooker; 131 return return_hooker;
132 } 132 }
133 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ 133 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
134 134
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