| 1 | /* SPDX-License-Identifier: (GPL-2.0-only or LGPL-2.1-only) |
| 2 | * |
| 3 | * wrapper/uprobes.h |
| 4 | * |
| 5 | * wrapper around uprobes. Using KALLSYMS to get its address when |
| 6 | * available, else we need to have a kernel that exports this function to GPL |
| 7 | * modules. |
| 8 | * |
| 9 | * Copyright (C) 2013 Yannick Brosseau <yannick.brosseau@gmail.com> |
| 10 | * Copyright (C) 2017 Francis Deslauriers <francis.deslauriers@efficios.com> |
| 11 | * |
| 12 | */ |
| 13 | |
| 14 | #ifndef _LTTNG_WRAPPER_UPROBES_H |
| 15 | #define _LTTNG_WRAPPER_UPROBES_H |
| 16 | |
| 17 | #include <linux/version.h> |
| 18 | |
| 19 | #if (LINUX_VERSION_CODE >= KERNEL_VERSION(3,5,0)) |
| 20 | #include <linux/uprobes.h> |
| 21 | |
| 22 | /* Use kallsym lookup for version before 3.9. */ |
| 23 | #if (LINUX_VERSION_CODE >= KERNEL_VERSION(3,9,0)) |
| 24 | |
| 25 | static inline |
| 26 | int wrapper_uprobe_register(struct inode *inode, loff_t offset, struct uprobe_consumer *uc) |
| 27 | { |
| 28 | return uprobe_register(inode, offset, uc); |
| 29 | } |
| 30 | |
| 31 | static inline |
| 32 | void wrapper_uprobe_unregister(struct inode *inode, loff_t offset, struct uprobe_consumer *uc) |
| 33 | { |
| 34 | uprobe_unregister(inode, offset, uc); |
| 35 | } |
| 36 | |
| 37 | #else /* Version < 3.9, use kallsym lookup. */ |
| 38 | #include "kallsyms.h" |
| 39 | |
| 40 | static inline |
| 41 | int wrapper_uprobe_register(struct inode *inode, loff_t offset, struct uprobe_consumer *uc) |
| 42 | { |
| 43 | int (*uprobe_register_sym)(struct inode *inode, loff_t offset, struct uprobe_consumer *uc); |
| 44 | |
| 45 | uprobe_register_sym = (void *) kallsyms_lookup_funcptr("uprobe_register"); |
| 46 | |
| 47 | if (uprobe_register_sym) { |
| 48 | return uprobe_register_sym(inode, offset, uc); |
| 49 | } else { |
| 50 | printk(KERN_WARNING "LTTng: uprobe_register symbol lookup failed.\n"); |
| 51 | return -EINVAL; |
| 52 | } |
| 53 | } |
| 54 | |
| 55 | /* |
| 56 | * Canary function to check for 'uprobe_register()' at compile time. |
| 57 | * |
| 58 | * From 'include/linux/uprobes.h': |
| 59 | * |
| 60 | * extern int uprobe_register(struct inode *inode, loff_t offset, struct uprobe_consumer *uc); |
| 61 | */ |
| 62 | static inline |
| 63 | int __canary__uprobe_register(struct inode *inode, loff_t offset, struct uprobe_consumer *uc) |
| 64 | { |
| 65 | return uprobe_register(inode, offset, uc); |
| 66 | } |
| 67 | |
| 68 | static inline |
| 69 | void wrapper_uprobe_unregister(struct inode *inode, loff_t offset, struct uprobe_consumer *uc) |
| 70 | { |
| 71 | int (*uprobe_unregister_sym)(struct inode *inode, loff_t offset, struct uprobe_consumer *uc); |
| 72 | |
| 73 | uprobe_unregister_sym = (void *) kallsyms_lookup_funcptr("uprobe_unregister"); |
| 74 | |
| 75 | if (uprobe_unregister_sym) { |
| 76 | uprobe_unregister_sym(inode, offset, uc); |
| 77 | } else { |
| 78 | printk(KERN_WARNING "LTTng: uprobe_unregister symbol lookup failed.\n"); |
| 79 | WARN_ON(1); |
| 80 | } |
| 81 | } |
| 82 | |
| 83 | /* |
| 84 | * Canary function to check for 'uprobe_unregister()' at compile time. |
| 85 | * |
| 86 | * From 'include/linux/uprobes.h': |
| 87 | * |
| 88 | * extern void uprobe_unregister(struct inode *inode, loff_t offset, struct uprobe_consumer *uc); |
| 89 | */ |
| 90 | static inline |
| 91 | void __canary__uprobe_unregister(struct inode *inode, loff_t offset, struct uprobe_consumer *uc) |
| 92 | { |
| 93 | uprobe_unregister(inode, offset, uc); |
| 94 | } |
| 95 | |
| 96 | #endif |
| 97 | #else |
| 98 | /* Version < 3.5, before uprobe was added. */ |
| 99 | struct uprobe_consumer {}; |
| 100 | |
| 101 | #endif |
| 102 | #endif |