projects / linux-block.git / blame
| Commit | Line | Data |
|---|---|---|
| b06457c8 SRV |
1 | // SPDX-License-Identifier: GPL-2.0-only |
| 2 | #include <linux/module.h> | |
| 3 | ||
| 4 | #include <linux/sched.h> /* for wake_up_process() */ | |
| 5 | #include <linux/ftrace.h> | |
| 1254cfbc | 6 | #include <asm/asm-offsets.h> |
| b06457c8 | 7 | |
| 0daf5cb2 JO |
8 | extern void my_direct_func(struct task_struct *p); |
| 9 | ||
| b06457c8 SRV |
10 | void my_direct_func(struct task_struct *p) |
| 11 | { | |
| 760f8bc7 | 12 | trace_printk("waking up %s-%d\n", p->comm, p->pid); |
| b06457c8 SRV |
13 | } |
| 14 | ||
| 15 | extern void my_tramp(void *); | |
| 16 | ||
| 1254cfbc HC |
17 | #ifdef CONFIG_X86_64 |
| 18 | ||
| 0aec21cf PZ |
19 | #include <asm/ibt.h> |
| 20 | ||
| b06457c8 SRV |
21 | asm ( |
| 22 | " .pushsection .text, \"ax\", @progbits\n" | |
| 9d907f1a | 23 | " .type my_tramp, @function\n" |
| 983df5f2 | 24 | " .globl my_tramp\n" |
| b06457c8 | 25 | " my_tramp:" |
| 0aec21cf | 26 | ASM_ENDBR |
| b06457c8 SRV |
27 | " pushq %rbp\n" |
| 28 | " movq %rsp, %rbp\n" | |
| 29 | " pushq %rdi\n" | |
| 30 | " call my_direct_func\n" | |
| 31 | " popq %rdi\n" | |
| 32 | " leave\n" | |
| b17c2baa | 33 | ASM_RET |
| 9d907f1a | 34 | " .size my_tramp, .-my_tramp\n" |
| b06457c8 SRV |
35 | " .popsection\n" |
| 36 | ); | |
| 37 | ||
| 1254cfbc HC |
38 | #endif /* CONFIG_X86_64 */ |
| 39 | ||
| 40 | #ifdef CONFIG_S390 | |
| 41 | ||
| 42 | asm ( | |
| 43 | " .pushsection .text, \"ax\", @progbits\n" | |
| 44 | " .type my_tramp, @function\n" | |
| 45 | " .globl my_tramp\n" | |
| 46 | " my_tramp:" | |
| 47 | " lgr %r1,%r15\n" | |
| 48 | " stmg %r0,%r5,"__stringify(__SF_GPRS)"(%r15)\n" | |
| 49 | " stg %r14,"__stringify(__SF_GPRS+8*8)"(%r15)\n" | |
| 50 | " aghi %r15,"__stringify(-STACK_FRAME_OVERHEAD)"\n" | |
| 51 | " stg %r1,"__stringify(__SF_BACKCHAIN)"(%r15)\n" | |
| 52 | " brasl %r14,my_direct_func\n" | |
| 53 | " aghi %r15,"__stringify(STACK_FRAME_OVERHEAD)"\n" | |
| 54 | " lmg %r0,%r5,"__stringify(__SF_GPRS)"(%r15)\n" | |
| 55 | " lg %r14,"__stringify(__SF_GPRS+8*8)"(%r15)\n" | |
| 56 | " lgr %r1,%r0\n" | |
| 57 | " br %r1\n" | |
| 58 | " .size my_tramp, .-my_tramp\n" | |
| 59 | " .popsection\n" | |
| 60 | ); | |
| 61 | ||
| 62 | #endif /* CONFIG_S390 */ | |
| b06457c8 SRV |
63 | |
| 64 | static int __init ftrace_direct_init(void) | |
| 65 | { | |
| 66 | return register_ftrace_direct((unsigned long)wake_up_process, | |
| 67 | (unsigned long)my_tramp); | |
| 68 | } | |
| 69 | ||
| 70 | static void __exit ftrace_direct_exit(void) | |
| 71 | { | |
| 72 | unregister_ftrace_direct((unsigned long)wake_up_process, | |
| 73 | (unsigned long)my_tramp); | |
| 74 | } | |
| 75 | ||
| 76 | module_init(ftrace_direct_init); | |
| 77 | module_exit(ftrace_direct_exit); | |
| 78 | ||
| 79 | MODULE_AUTHOR("Steven Rostedt"); | |
| 80 | MODULE_DESCRIPTION("Example use case of using register_ftrace_direct()"); | |
| 81 | MODULE_LICENSE("GPL"); |