diff options
author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /kernel/exec_domain.c |
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'kernel/exec_domain.c')
-rw-r--r-- | kernel/exec_domain.c | 209 |
1 files changed, 209 insertions, 0 deletions
diff --git a/kernel/exec_domain.c b/kernel/exec_domain.c new file mode 100644 index 000000000000..867d6dbeb574 --- /dev/null +++ b/kernel/exec_domain.c | |||
@@ -0,0 +1,209 @@ | |||
1 | /* | ||
2 | * Handling of different ABIs (personalities). | ||
3 | * | ||
4 | * We group personalities into execution domains which have their | ||
5 | * own handlers for kernel entry points, signal mapping, etc... | ||
6 | * | ||
7 | * 2001-05-06 Complete rewrite, Christoph Hellwig (hch@infradead.org) | ||
8 | */ | ||
9 | |||
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/syscalls.h> | ||
18 | #include <linux/sysctl.h> | ||
19 | #include <linux/types.h> | ||
20 | |||
21 | |||
22 | static void default_handler(int, struct pt_regs *); | ||
23 | |||
24 | static struct exec_domain *exec_domains = &default_exec_domain; | ||
25 | static DEFINE_RWLOCK(exec_domains_lock); | ||
26 | |||
27 | |||
28 | static u_long ident_map[32] = { | ||
29 | 0, 1, 2, 3, 4, 5, 6, 7, | ||
30 | 8, 9, 10, 11, 12, 13, 14, 15, | ||
31 | 16, 17, 18, 19, 20, 21, 22, 23, | ||
32 | 24, 25, 26, 27, 28, 29, 30, 31 | ||
33 | }; | ||
34 | |||
35 | struct exec_domain default_exec_domain = { | ||
36 | .name = "Linux", /* name */ | ||
37 | .handler = default_handler, /* lcall7 causes a seg fault. */ | ||
38 | .pers_low = 0, /* PER_LINUX personality. */ | ||
39 | .pers_high = 0, /* PER_LINUX personality. */ | ||
40 | .signal_map = ident_map, /* Identity map signals. */ | ||
41 | .signal_invmap = ident_map, /* - both ways. */ | ||
42 | }; | ||
43 | |||
44 | |||
45 | static void | ||
46 | default_handler(int segment, struct pt_regs *regp) | ||
47 | { | ||
48 | set_personality(0); | ||
49 | |||
50 | if (current_thread_info()->exec_domain->handler != default_handler) | ||
51 | current_thread_info()->exec_domain->handler(segment, regp); | ||
52 | else | ||
53 | send_sig(SIGSEGV, current, 1); | ||
54 | } | ||
55 | |||
56 | static struct exec_domain * | ||
57 | lookup_exec_domain(u_long personality) | ||
58 | { | ||
59 | struct exec_domain * ep; | ||
60 | u_long pers = personality(personality); | ||
61 | |||
62 | read_lock(&exec_domains_lock); | ||
63 | for (ep = exec_domains; ep; ep = ep->next) { | ||
64 | if (pers >= ep->pers_low && pers <= ep->pers_high) | ||
65 | if (try_module_get(ep->module)) | ||
66 | goto out; | ||
67 | } | ||
68 | |||
69 | #ifdef CONFIG_KMOD | ||
70 | read_unlock(&exec_domains_lock); | ||
71 | request_module("personality-%ld", pers); | ||
72 | read_lock(&exec_domains_lock); | ||
73 | |||
74 | for (ep = exec_domains; ep; ep = ep->next) { | ||
75 | if (pers >= ep->pers_low && pers <= ep->pers_high) | ||
76 | if (try_module_get(ep->module)) | ||
77 | goto out; | ||
78 | } | ||
79 | #endif | ||
80 | |||
81 | ep = &default_exec_domain; | ||
82 | out: | ||
83 | read_unlock(&exec_domains_lock); | ||
84 | return (ep); | ||
85 | } | ||
86 | |||
87 | int | ||
88 | register_exec_domain(struct exec_domain *ep) | ||
89 | { | ||
90 | struct exec_domain *tmp; | ||
91 | int err = -EBUSY; | ||
92 | |||
93 | if (ep == NULL) | ||
94 | return -EINVAL; | ||
95 | |||
96 | if (ep->next != NULL) | ||
97 | return -EBUSY; | ||
98 | |||
99 | write_lock(&exec_domains_lock); | ||
100 | for (tmp = exec_domains; tmp; tmp = tmp->next) { | ||
101 | if (tmp == ep) | ||
102 | goto out; | ||
103 | } | ||
104 | |||
105 | ep->next = exec_domains; | ||
106 | exec_domains = ep; | ||
107 | err = 0; | ||
108 | |||
109 | out: | ||
110 | write_unlock(&exec_domains_lock); | ||
111 | return (err); | ||
112 | } | ||
113 | |||
114 | int | ||
115 | unregister_exec_domain(struct exec_domain *ep) | ||
116 | { | ||
117 | struct exec_domain **epp; | ||
118 | |||
119 | epp = &exec_domains; | ||
120 | write_lock(&exec_domains_lock); | ||
121 | for (epp = &exec_domains; *epp; epp = &(*epp)->next) { | ||
122 | if (ep == *epp) | ||
123 | goto unregister; | ||
124 | } | ||
125 | write_unlock(&exec_domains_lock); | ||
126 | return -EINVAL; | ||
127 | |||
128 | unregister: | ||
129 | *epp = ep->next; | ||
130 | ep->next = NULL; | ||
131 | write_unlock(&exec_domains_lock); | ||
132 | return 0; | ||
133 | } | ||
134 | |||
135 | int | ||
136 | __set_personality(u_long personality) | ||
137 | { | ||
138 | struct exec_domain *ep, *oep; | ||
139 | |||
140 | ep = lookup_exec_domain(personality); | ||
141 | if (ep == current_thread_info()->exec_domain) { | ||
142 | current->personality = personality; | ||
143 | return 0; | ||
144 | } | ||
145 | |||
146 | if (atomic_read(¤t->fs->count) != 1) { | ||
147 | struct fs_struct *fsp, *ofsp; | ||
148 | |||
149 | fsp = copy_fs_struct(current->fs); | ||
150 | if (fsp == NULL) { | ||
151 | module_put(ep->module); | ||
152 | return -ENOMEM; | ||
153 | } | ||
154 | |||
155 | task_lock(current); | ||
156 | ofsp = current->fs; | ||
157 | current->fs = fsp; | ||
158 | task_unlock(current); | ||
159 | |||
160 | put_fs_struct(ofsp); | ||
161 | } | ||
162 | |||
163 | /* | ||
164 | * At that point we are guaranteed to be the sole owner of | ||
165 | * current->fs. | ||
166 | */ | ||
167 | |||
168 | current->personality = personality; | ||
169 | oep = current_thread_info()->exec_domain; | ||
170 | current_thread_info()->exec_domain = ep; | ||
171 | set_fs_altroot(); | ||
172 | |||
173 | module_put(oep->module); | ||
174 | return 0; | ||
175 | } | ||
176 | |||
177 | int | ||
178 | get_exec_domain_list(char *page) | ||
179 | { | ||
180 | struct exec_domain *ep; | ||
181 | int len = 0; | ||
182 | |||
183 | read_lock(&exec_domains_lock); | ||
184 | for (ep = exec_domains; ep && len < PAGE_SIZE - 80; ep = ep->next) | ||
185 | len += sprintf(page + len, "%d-%d\t%-16s\t[%s]\n", | ||
186 | ep->pers_low, ep->pers_high, ep->name, | ||
187 | module_name(ep->module)); | ||
188 | read_unlock(&exec_domains_lock); | ||
189 | return (len); | ||
190 | } | ||
191 | |||
192 | asmlinkage long | ||
193 | sys_personality(u_long personality) | ||
194 | { | ||
195 | u_long old = current->personality; | ||
196 | |||
197 | if (personality != 0xffffffff) { | ||
198 | set_personality(personality); | ||
199 | if (current->personality != personality) | ||
200 | return -EINVAL; | ||
201 | } | ||
202 | |||
203 | return (long)old; | ||
204 | } | ||
205 | |||
206 | |||
207 | EXPORT_SYMBOL(register_exec_domain); | ||
208 | EXPORT_SYMBOL(unregister_exec_domain); | ||
209 | EXPORT_SYMBOL(__set_personality); | ||