| 1 | /* SPDX-License-Identifier: (GPL-2.0 or LGPL-2.1) |
| 2 | * |
| 3 | * lttng-syscalls-extractor.c |
| 4 | * |
| 5 | * Dump syscall metadata to console. |
| 6 | * |
| 7 | * Copyright 2011 Mathieu Desnoyers <mathieu.desnoyers@efficios.com> |
| 8 | * Copyright 2011 Julien Desfossez <julien.desfossez@polymtl.ca> |
| 9 | */ |
| 10 | |
| 11 | #include <linux/module.h> |
| 12 | #include <linux/kernel.h> |
| 13 | #include <linux/types.h> |
| 14 | #include <linux/list.h> |
| 15 | #include <linux/err.h> |
| 16 | #include <linux/slab.h> |
| 17 | #include <linux/kallsyms.h> |
| 18 | #include <linux/dcache.h> |
| 19 | #include <linux/trace_events.h> |
| 20 | #include <trace/syscall.h> |
| 21 | #include <asm/syscall.h> |
| 22 | |
| 23 | #ifndef CONFIG_FTRACE_SYSCALLS |
| 24 | #error "You need to set CONFIG_FTRACE_SYSCALLS=y" |
| 25 | #endif |
| 26 | |
| 27 | #ifndef CONFIG_KALLSYMS_ALL |
| 28 | #error "You need to set CONFIG_KALLSYMS_ALL=y" |
| 29 | #endif |
| 30 | |
| 31 | /* |
| 32 | * The 'ident' parameter is prepended to each printk line to help |
| 33 | * extract the proper lines from dmesg. |
| 34 | */ |
| 35 | static char *ident = ""; |
| 36 | module_param(ident, charp, 0); |
| 37 | |
| 38 | static struct syscall_metadata **__start_syscalls_metadata; |
| 39 | static struct syscall_metadata **__stop_syscalls_metadata; |
| 40 | |
| 41 | static __init |
| 42 | struct syscall_metadata *find_syscall_meta(unsigned long syscall) |
| 43 | { |
| 44 | struct syscall_metadata **iter; |
| 45 | |
| 46 | for (iter = __start_syscalls_metadata; |
| 47 | iter < __stop_syscalls_metadata; iter++) { |
| 48 | if ((*iter)->syscall_nr == syscall) |
| 49 | return (*iter); |
| 50 | } |
| 51 | return NULL; |
| 52 | } |
| 53 | |
| 54 | int init_module(void) |
| 55 | { |
| 56 | struct syscall_metadata *meta; |
| 57 | int i; |
| 58 | |
| 59 | __start_syscalls_metadata = (void *) kallsyms_lookup_name("__start_syscalls_metadata"); |
| 60 | __stop_syscalls_metadata = (void *) kallsyms_lookup_name("__stop_syscalls_metadata"); |
| 61 | |
| 62 | printk("%s---START---\n", ident); |
| 63 | for (i = 0; i < NR_syscalls; i++) { |
| 64 | int j; |
| 65 | |
| 66 | meta = find_syscall_meta(i); |
| 67 | if (!meta) |
| 68 | continue; |
| 69 | printk("%ssyscall %s nr %d nbargs %d ", |
| 70 | ident, meta->name, meta->syscall_nr, meta->nb_args); |
| 71 | printk(KERN_CONT "types: ("); |
| 72 | for (j = 0; j < meta->nb_args; j++) { |
| 73 | if (j > 0) |
| 74 | printk(KERN_CONT ", "); |
| 75 | printk(KERN_CONT "%s", meta->types[j]); |
| 76 | } |
| 77 | printk(KERN_CONT ") "); |
| 78 | printk(KERN_CONT "args: ("); |
| 79 | for (j = 0; j < meta->nb_args; j++) { |
| 80 | if (j > 0) |
| 81 | printk(KERN_CONT ", "); |
| 82 | printk(KERN_CONT "%s", meta->args[j]); |
| 83 | } |
| 84 | printk(KERN_CONT ")\n"); |
| 85 | } |
| 86 | printk("%s---END---\n", ident); |
| 87 | |
| 88 | /* |
| 89 | * This module always fails to load. |
| 90 | */ |
| 91 | return -1; |
| 92 | } |
| 93 | |
| 94 | void cleanup_module(void) |
| 95 | { |
| 96 | } |
| 97 | |
| 98 | MODULE_LICENSE("GPL"); |