1QUERY_MODULE(2) Linux Programmer's Manual QUERY_MODULE(2)
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6 query_module - query the kernel for various bits pertaining to modules
7
9 #include <linux/module.h>
10 int query_module(const char *name, int which, void *buf,
12 size_t bufsize, size_t *ret);
13 Note: No declaration of this system call is provided in glibc headers;
15 see NOTES.
16
18 Note: This system call is present only in kernels before Linux 2.6.
19 query_module() requests information from the kernel about loadable mod‐
21 ules. The returned information is placed in the buffer pointed to by
22 buf. The caller must specify the size of buf in bufsize. The precise
23 nature and format of the returned information depend on the operation
24 specified by which. Some operations require name to identify a cur‐
25 rently loaded module, some allow name to be NULL, indicating the kernel
26 proper.
27 The following values can be specified for which:
29 0 Returns success, if the kernel supports query_module(). Used to
31 probe for availability of the system call.
32 QM_MODULES
34 Returns the names of all loaded modules. The returned buffer
35 consists of a sequence of null-terminated strings; ret is set to
36 the number of modules.
37 QM_DEPS
39 Returns the names of all modules used by the indicated module.
40 The returned buffer consists of a sequence of null-terminated
41 strings; ret is set to the number of modules.
42 QM_REFS
44 Returns the names of all modules using the indicated module.
45 This is the inverse of QM_DEPS. The returned buffer consists of
46 a sequence of null-terminated strings; ret is set to the number
47 of modules.
48 QM_SYMBOLS
50 Returns the symbols and values exported by the kernel or the in‐
51 dicated module. The returned buffer is an array of structures
52 of the following form
53 struct module_symbol {
55 unsigned long value;
56 unsigned long name;
57 };
58 followed by null-terminated strings. The value of name is the
60 character offset of the string relative to the start of buf; ret
61 is set to the number of symbols.
62 QM_INFO
64 Returns miscellaneous information about the indicated module.
65 The output buffer format is:
66 struct module_info {
68 unsigned long address;
69 unsigned long size;
70 unsigned long flags;
71 };
72 where address is the kernel address at which the module resides,
74 size is the size of the module in bytes, and flags is a mask of
75 MOD_RUNNING, MOD_AUTOCLEAN, and so on, that indicates the cur‐
76 rent status of the module (see the Linux kernel source file in‐
77 clude/linux/module.h). ret is set to the size of the mod‐
78 ule_info structure.
79
81 On success, zero is returned. On error, -1 is returned and errno is
82 set appropriately.
83
85 EFAULT At least one of name, buf, or ret was outside the program's ac‐
86 cessible address space.
87 EINVAL Invalid which; or name is NULL (indicating "the kernel"), but
89 this is not permitted with the specified value of which.
90 ENOENT No module by that name exists.
92 ENOSPC The buffer size provided was too small. ret is set to the mini‐
94 mum size needed.
95 ENOSYS query_module() is not supported in this version of the kernel
97 (e.g., the kernel is version 2.6 or later).
98
100 This system call is present on Linux only up until kernel 2.4; it was
101 removed in Linux 2.6.
102
104 query_module() is Linux-specific.
105
107 Some of the information that was formerly available via query_module()
108 can be obtained from /proc/modules, /proc/kallsyms, and the files under
109 the directory /sys/module.
110 The query_module() system call is not supported by glibc. No declara‐
112 tion is provided in glibc headers, but, through a quirk of history,
113 glibc does export an ABI for this system call. Therefore, in order to
114 employ this system call, it is sufficient to manually declare the in‐
115 terface in your code; alternatively, you can invoke the system call us‐
116 ing syscall(2).
117
119 create_module(2), delete_module(2), get_kernel_syms(2), init_module(2),
120 lsmod(8), modinfo(8)
121
123 This page is part of release 5.10 of the Linux man-pages project. A
124 description of the project, information about reporting bugs, and the
125 latest version of this page, can be found at
126 https://www.kernel.org/doc/man-pages/.
127Linux 2017-09-15 QUERY_MODULE(2)