1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | #include <linux/module.h> |
3 | |
4 | #include <linux/mm.h> /* for handle_mm_fault() */ |
5 | #include <linux/ftrace.h> |
6 | #include <linux/sched/stat.h> |
7 | #ifndef CONFIG_ARM64 |
8 | #include <asm/asm-offsets.h> |
9 | #endif |
10 | |
11 | extern void my_direct_func(unsigned long ip); |
12 | |
13 | void my_direct_func(unsigned long ip) |
14 | { |
15 | trace_printk("ip %lx\n" , ip); |
16 | } |
17 | |
18 | extern void my_tramp(void *); |
19 | |
20 | #ifdef CONFIG_RISCV |
21 | #include <asm/asm.h> |
22 | |
23 | asm ( |
24 | " .pushsection .text, \"ax\", @progbits\n" |
25 | " .type my_tramp, @function\n" |
26 | " .globl my_tramp\n" |
27 | " my_tramp:\n" |
28 | " addi sp,sp,-3*" SZREG"\n" |
29 | " " REG_S" a0,0*" SZREG"(sp)\n" |
30 | " " REG_S" t0,1*" SZREG"(sp)\n" |
31 | " " REG_S" ra,2*" SZREG"(sp)\n" |
32 | " mv a0,t0\n" |
33 | " call my_direct_func\n" |
34 | " " REG_L" a0,0*" SZREG"(sp)\n" |
35 | " " REG_L" t0,1*" SZREG"(sp)\n" |
36 | " " REG_L" ra,2*" SZREG"(sp)\n" |
37 | " addi sp,sp,3*" SZREG"\n" |
38 | " jr t0\n" |
39 | " .size my_tramp, .-my_tramp\n" |
40 | " .popsection\n" |
41 | ); |
42 | |
43 | #endif /* CONFIG_RISCV */ |
44 | |
45 | #ifdef CONFIG_X86_64 |
46 | |
47 | #include <asm/ibt.h> |
48 | #include <asm/nospec-branch.h> |
49 | |
50 | asm ( |
51 | " .pushsection .text, \"ax\", @progbits\n" |
52 | " .type my_tramp, @function\n" |
53 | " .globl my_tramp\n" |
54 | " my_tramp:" |
55 | ASM_ENDBR |
56 | " pushq %rbp\n" |
57 | " movq %rsp, %rbp\n" |
58 | CALL_DEPTH_ACCOUNT |
59 | " pushq %rdi\n" |
60 | " movq 8(%rbp), %rdi\n" |
61 | " call my_direct_func\n" |
62 | " popq %rdi\n" |
63 | " leave\n" |
64 | ASM_RET |
65 | " .size my_tramp, .-my_tramp\n" |
66 | " .popsection\n" |
67 | ); |
68 | |
69 | #endif /* CONFIG_X86_64 */ |
70 | |
71 | #ifdef CONFIG_S390 |
72 | |
73 | asm ( |
74 | " .pushsection .text, \"ax\", @progbits\n" |
75 | " .type my_tramp, @function\n" |
76 | " .globl my_tramp\n" |
77 | " my_tramp:" |
78 | " lgr %r1,%r15\n" |
79 | " stmg %r0,%r5," __stringify(__SF_GPRS)"(%r15)\n" |
80 | " stg %r14," __stringify(__SF_GPRS+8*8)"(%r15)\n" |
81 | " aghi %r15," __stringify(-STACK_FRAME_OVERHEAD)"\n" |
82 | " stg %r1," __stringify(__SF_BACKCHAIN)"(%r15)\n" |
83 | " lgr %r2,%r0\n" |
84 | " brasl %r14,my_direct_func\n" |
85 | " aghi %r15," __stringify(STACK_FRAME_OVERHEAD)"\n" |
86 | " lmg %r0,%r5," __stringify(__SF_GPRS)"(%r15)\n" |
87 | " lg %r14," __stringify(__SF_GPRS+8*8)"(%r15)\n" |
88 | " lgr %r1,%r0\n" |
89 | " br %r1\n" |
90 | " .size my_tramp, .-my_tramp\n" |
91 | " .popsection\n" |
92 | ); |
93 | |
94 | #endif /* CONFIG_S390 */ |
95 | |
96 | #ifdef CONFIG_ARM64 |
97 | |
98 | asm ( |
99 | " .pushsection .text, \"ax\", @progbits\n" |
100 | " .type my_tramp, @function\n" |
101 | " .globl my_tramp\n" |
102 | " my_tramp:" |
103 | " hint 34\n" // bti c |
104 | " sub sp, sp, #32\n" |
105 | " stp x9, x30, [sp]\n" |
106 | " str x0, [sp, #16]\n" |
107 | " mov x0, x30\n" |
108 | " bl my_direct_func\n" |
109 | " ldp x30, x9, [sp]\n" |
110 | " ldr x0, [sp, #16]\n" |
111 | " add sp, sp, #32\n" |
112 | " ret x9\n" |
113 | " .size my_tramp, .-my_tramp\n" |
114 | " .popsection\n" |
115 | ); |
116 | |
117 | #endif /* CONFIG_ARM64 */ |
118 | |
119 | #ifdef CONFIG_LOONGARCH |
120 | |
121 | #include <asm/asm.h> |
122 | asm ( |
123 | " .pushsection .text, \"ax\", @progbits\n" |
124 | " .type my_tramp, @function\n" |
125 | " .globl my_tramp\n" |
126 | " my_tramp:\n" |
127 | " addi.d $sp, $sp, -32\n" |
128 | " st.d $a0, $sp, 0\n" |
129 | " st.d $t0, $sp, 8\n" |
130 | " st.d $ra, $sp, 16\n" |
131 | " move $a0, $t0\n" |
132 | " bl my_direct_func\n" |
133 | " ld.d $a0, $sp, 0\n" |
134 | " ld.d $t0, $sp, 8\n" |
135 | " ld.d $ra, $sp, 16\n" |
136 | " addi.d $sp, $sp, 32\n" |
137 | " jr $t0\n" |
138 | " .size my_tramp, .-my_tramp\n" |
139 | " .popsection\n" |
140 | ); |
141 | |
142 | #endif /* CONFIG_LOONGARCH */ |
143 | |
144 | static struct ftrace_ops direct; |
145 | |
146 | static int __init ftrace_direct_multi_init(void) |
147 | { |
148 | ftrace_set_filter_ip(ops: &direct, ip: (unsigned long) wake_up_process, remove: 0, reset: 0); |
149 | ftrace_set_filter_ip(ops: &direct, ip: (unsigned long) schedule, remove: 0, reset: 0); |
150 | |
151 | return register_ftrace_direct(ops: &direct, addr: (unsigned long) my_tramp); |
152 | } |
153 | |
154 | static void __exit ftrace_direct_multi_exit(void) |
155 | { |
156 | unregister_ftrace_direct(ops: &direct, addr: (unsigned long) my_tramp, free_filters: true); |
157 | } |
158 | |
159 | module_init(ftrace_direct_multi_init); |
160 | module_exit(ftrace_direct_multi_exit); |
161 | |
162 | MODULE_AUTHOR("Jiri Olsa" ); |
163 | MODULE_DESCRIPTION("Example use case of using register_ftrace_direct_multi()" ); |
164 | MODULE_LICENSE("GPL" ); |
165 | |