2 * Handling of different ABIs (personalities).
4 * We group personalities into execution domains which have their
5 * own handlers for kernel entry points, signal mapping, etc...
7 * 2001-05-06 Complete rewrite, Christoph Hellwig (hch@infradead.org)
10 #include <linux/config.h>
11 #include <linux/init.h>
12 #include <linux/kernel.h>
13 #include <linux/kmod.h>
14 #include <linux/module.h>
15 #include <linux/personality.h>
16 #include <linux/sched.h>
17 #include <linux/sysctl.h>
18 #include <linux/types.h>
21 static void default_handler(int, struct pt_regs
*);
23 static struct exec_domain
*exec_domains
= &default_exec_domain
;
24 static rwlock_t exec_domains_lock
= RW_LOCK_UNLOCKED
;
27 static u_long ident_map
[32] = {
28 0, 1, 2, 3, 4, 5, 6, 7,
29 8, 9, 10, 11, 12, 13, 14, 15,
30 16, 17, 18, 19, 20, 21, 22, 23,
31 24, 25, 26, 27, 28, 29, 30, 31
34 struct exec_domain default_exec_domain
= {
35 .name
= "Linux", /* name */
36 .handler
= default_handler
, /* lcall7 causes a seg fault. */
37 .pers_low
= 0, /* PER_LINUX personality. */
38 .pers_high
= 0, /* PER_LINUX personality. */
39 .signal_map
= ident_map
, /* Identity map signals. */
40 .signal_invmap
= ident_map
, /* - both ways. */
45 default_handler(int segment
, struct pt_regs
*regp
)
50 * This may have been a static linked SVr4 binary, so we would
51 * have the personality set incorrectly. Or it might have been
52 * a Solaris/x86 binary. We can tell which because the former
53 * uses lcall7, while the latter used lcall 0x27.
54 * Try to find or load the appropriate personality, and fall back
55 * to just forcing a SEGV.
57 * XXX: this is IA32-specific and should be moved to the MD-tree.
62 pers
= abi_defhandler_lcall7
;
69 set_personality(pers
);
71 if (current_thread_info()->exec_domain
->handler
!= default_handler
)
72 current_thread_info()->exec_domain
->handler(segment
, regp
);
74 send_sig(SIGSEGV
, current
, 1);
77 static struct exec_domain
*
78 lookup_exec_domain(u_long personality
)
80 struct exec_domain
* ep
;
81 u_long pers
= personality(personality
);
83 read_lock(&exec_domains_lock
);
84 for (ep
= exec_domains
; ep
; ep
= ep
->next
) {
85 if (pers
>= ep
->pers_low
&& pers
<= ep
->pers_high
)
86 if (try_module_get(ep
->module
))
91 read_unlock(&exec_domains_lock
);
92 request_module("personality-%ld", pers
);
93 read_lock(&exec_domains_lock
);
95 for (ep
= exec_domains
; ep
; ep
= ep
->next
) {
96 if (pers
>= ep
->pers_low
&& pers
<= ep
->pers_high
)
97 if (try_module_get(ep
->module
))
102 ep
= &default_exec_domain
;
104 read_unlock(&exec_domains_lock
);
109 register_exec_domain(struct exec_domain
*ep
)
111 struct exec_domain
*tmp
;
117 if (ep
->next
!= NULL
)
120 write_lock(&exec_domains_lock
);
121 for (tmp
= exec_domains
; tmp
; tmp
= tmp
->next
) {
126 ep
->next
= exec_domains
;
131 write_unlock(&exec_domains_lock
);
136 unregister_exec_domain(struct exec_domain
*ep
)
138 struct exec_domain
**epp
;
141 write_lock(&exec_domains_lock
);
142 for (epp
= &exec_domains
; *epp
; epp
= &(*epp
)->next
) {
146 write_unlock(&exec_domains_lock
);
152 write_unlock(&exec_domains_lock
);
157 __set_personality(u_long personality
)
159 struct exec_domain
*ep
, *oep
;
161 ep
= lookup_exec_domain(personality
);
162 if (ep
== current_thread_info()->exec_domain
) {
163 current
->personality
= personality
;
167 if (atomic_read(¤t
->fs
->count
) != 1) {
168 struct fs_struct
*fsp
, *ofsp
;
170 fsp
= copy_fs_struct(current
->fs
);
172 module_put(ep
->module
);
179 task_unlock(current
);
185 * At that point we are guaranteed to be the sole owner of
189 current
->personality
= personality
;
190 oep
= current_thread_info()->exec_domain
;
191 current_thread_info()->exec_domain
= ep
;
194 module_put(oep
->module
);
199 get_exec_domain_list(char *page
)
201 struct exec_domain
*ep
;
204 read_lock(&exec_domains_lock
);
205 for (ep
= exec_domains
; ep
&& len
< PAGE_SIZE
- 80; ep
= ep
->next
)
206 len
+= sprintf(page
+ len
, "%d-%d\t%-16s\t[%s]\n",
207 ep
->pers_low
, ep
->pers_high
, ep
->name
,
208 module_name(ep
->module
));
209 read_unlock(&exec_domains_lock
);
214 sys_personality(u_long personality
)
216 u_long old
= current
->personality
;;
218 if (personality
!= 0xffffffff) {
219 set_personality(personality
);
220 if (current
->personality
!= personality
)
228 EXPORT_SYMBOL(register_exec_domain
);
229 EXPORT_SYMBOL(unregister_exec_domain
);
230 EXPORT_SYMBOL(__set_personality
);
233 * We have to have all sysctl handling for the Linux-ABI
234 * in one place as the dynamic registration of sysctls is
235 * horribly crufty in Linux <= 2.4.
237 * I hope the new sysctl schemes discussed for future versions
238 * will obsolete this.
243 u_long abi_defhandler_coff
= PER_SCOSVR3
;
244 u_long abi_defhandler_elf
= PER_LINUX
;
245 u_long abi_defhandler_lcall7
= PER_SVR4
;
246 u_long abi_defhandler_libcso
= PER_SVR4
;
248 int abi_fake_utsname
;
250 static struct ctl_table abi_table
[] = {
252 .ctl_name
= ABI_DEFHANDLER_COFF
,
253 .procname
= "defhandler_coff",
254 .data
= &abi_defhandler_coff
,
255 .maxlen
= sizeof(int),
257 .proc_handler
= &proc_doulongvec_minmax
,
260 .ctl_name
= ABI_DEFHANDLER_ELF
,
261 .procname
= "defhandler_elf",
262 .data
= &abi_defhandler_elf
,
263 .maxlen
= sizeof(int),
265 .proc_handler
= &proc_doulongvec_minmax
,
268 .ctl_name
= ABI_DEFHANDLER_LCALL7
,
269 .procname
= "defhandler_lcall7",
270 .data
= &abi_defhandler_lcall7
,
271 .maxlen
= sizeof(int),
273 .proc_handler
= &proc_doulongvec_minmax
,
276 .ctl_name
= ABI_DEFHANDLER_LIBCSO
,
277 .procname
= "defhandler_libcso",
278 .data
= &abi_defhandler_libcso
,
279 .maxlen
= sizeof(int),
281 .proc_handler
= &proc_doulongvec_minmax
,
284 .ctl_name
= ABI_TRACE
,
286 .data
= &abi_traceflg
,
287 .maxlen
= sizeof(u_int
),
289 .proc_handler
= &proc_dointvec
,
292 .ctl_name
= ABI_FAKE_UTSNAME
,
293 .procname
= "fake_utsname",
294 .data
= &abi_fake_utsname
,
295 .maxlen
= sizeof(int),
297 .proc_handler
= &proc_dointvec
,
302 static struct ctl_table abi_root_table
[] = {
313 abi_register_sysctl(void)
315 register_sysctl_table(abi_root_table
, 1);
319 __initcall(abi_register_sysctl
);
322 EXPORT_SYMBOL(abi_defhandler_coff
);
323 EXPORT_SYMBOL(abi_defhandler_elf
);
324 EXPORT_SYMBOL(abi_defhandler_lcall7
);
325 EXPORT_SYMBOL(abi_defhandler_libcso
);
326 EXPORT_SYMBOL(abi_traceflg
);
327 EXPORT_SYMBOL(abi_fake_utsname
);