Line data Source code
1 : // SPDX-License-Identifier: GPL-2.0
2 : #include <linux/compat.h>
3 : #include <linux/uaccess.h>
4 : #include <linux/ptrace.h>
5 :
6 : /*
7 : * The compat_siginfo_t structure and handing code is very easy
8 : * to break in several ways. It must always be updated when new
9 : * updates are made to the main siginfo_t, and
10 : * copy_siginfo_to_user32() must be updated when the
11 : * (arch-independent) copy_siginfo_to_user() is updated.
12 : *
13 : * It is also easy to put a new member in the compat_siginfo_t
14 : * which has implicit alignment which can move internal structure
15 : * alignment around breaking the ABI. This can happen if you,
16 : * for instance, put a plain 64-bit value in there.
17 : */
18 9309 : static inline void signal_compat_build_tests(void)
19 : {
20 9309 : int _sifields_offset = offsetof(compat_siginfo_t, _sifields);
21 :
22 : /*
23 : * If adding a new si_code, there is probably new data in
24 : * the siginfo. Make sure folks bumping the si_code
25 : * limits also have to look at this code. Make sure any
26 : * new fields are handled in copy_siginfo_to_user32()!
27 : */
28 9309 : BUILD_BUG_ON(NSIGILL != 11);
29 9309 : BUILD_BUG_ON(NSIGFPE != 15);
30 9309 : BUILD_BUG_ON(NSIGSEGV != 9);
31 9309 : BUILD_BUG_ON(NSIGBUS != 5);
32 9309 : BUILD_BUG_ON(NSIGTRAP != 5);
33 9309 : BUILD_BUG_ON(NSIGCHLD != 6);
34 9309 : BUILD_BUG_ON(NSIGSYS != 2);
35 :
36 : /* This is part of the ABI and can never change in size: */
37 9309 : BUILD_BUG_ON(sizeof(compat_siginfo_t) != 128);
38 : /*
39 : * The offsets of all the (unioned) si_fields are fixed
40 : * in the ABI, of course. Make sure none of them ever
41 : * move and are always at the beginning:
42 : */
43 9309 : BUILD_BUG_ON(offsetof(compat_siginfo_t, _sifields) != 3 * sizeof(int));
44 : #define CHECK_CSI_OFFSET(name) BUILD_BUG_ON(_sifields_offset != offsetof(compat_siginfo_t, _sifields.name))
45 :
46 9309 : BUILD_BUG_ON(offsetof(siginfo_t, si_signo) != 0);
47 9309 : BUILD_BUG_ON(offsetof(siginfo_t, si_errno) != 4);
48 9309 : BUILD_BUG_ON(offsetof(siginfo_t, si_code) != 8);
49 :
50 9309 : BUILD_BUG_ON(offsetof(compat_siginfo_t, si_signo) != 0);
51 9309 : BUILD_BUG_ON(offsetof(compat_siginfo_t, si_errno) != 4);
52 9309 : BUILD_BUG_ON(offsetof(compat_siginfo_t, si_code) != 8);
53 : /*
54 : * Ensure that the size of each si_field never changes.
55 : * If it does, it is a sign that the
56 : * copy_siginfo_to_user32() code below needs to updated
57 : * along with the size in the CHECK_SI_SIZE().
58 : *
59 : * We repeat this check for both the generic and compat
60 : * siginfos.
61 : *
62 : * Note: it is OK for these to grow as long as the whole
63 : * structure stays within the padding size (checked
64 : * above).
65 : */
66 : #define CHECK_CSI_SIZE(name, size) BUILD_BUG_ON(size != sizeof(((compat_siginfo_t *)0)->_sifields.name))
67 : #define CHECK_SI_SIZE(name, size) BUILD_BUG_ON(size != sizeof(((siginfo_t *)0)->_sifields.name))
68 :
69 9309 : CHECK_CSI_OFFSET(_kill);
70 9309 : CHECK_CSI_SIZE (_kill, 2*sizeof(int));
71 9309 : CHECK_SI_SIZE (_kill, 2*sizeof(int));
72 :
73 9309 : BUILD_BUG_ON(offsetof(siginfo_t, si_pid) != 0x10);
74 9309 : BUILD_BUG_ON(offsetof(siginfo_t, si_uid) != 0x14);
75 9309 : BUILD_BUG_ON(offsetof(compat_siginfo_t, si_pid) != 0xC);
76 9309 : BUILD_BUG_ON(offsetof(compat_siginfo_t, si_uid) != 0x10);
77 :
78 9309 : CHECK_CSI_OFFSET(_timer);
79 9309 : CHECK_CSI_SIZE (_timer, 3*sizeof(int));
80 9309 : CHECK_SI_SIZE (_timer, 6*sizeof(int));
81 :
82 9309 : BUILD_BUG_ON(offsetof(siginfo_t, si_tid) != 0x10);
83 9309 : BUILD_BUG_ON(offsetof(siginfo_t, si_overrun) != 0x14);
84 9309 : BUILD_BUG_ON(offsetof(siginfo_t, si_value) != 0x18);
85 9309 : BUILD_BUG_ON(offsetof(compat_siginfo_t, si_tid) != 0x0C);
86 9309 : BUILD_BUG_ON(offsetof(compat_siginfo_t, si_overrun) != 0x10);
87 9309 : BUILD_BUG_ON(offsetof(compat_siginfo_t, si_value) != 0x14);
88 :
89 9309 : CHECK_CSI_OFFSET(_rt);
90 9309 : CHECK_CSI_SIZE (_rt, 3*sizeof(int));
91 9309 : CHECK_SI_SIZE (_rt, 4*sizeof(int));
92 :
93 9309 : BUILD_BUG_ON(offsetof(siginfo_t, si_pid) != 0x10);
94 9309 : BUILD_BUG_ON(offsetof(siginfo_t, si_uid) != 0x14);
95 9309 : BUILD_BUG_ON(offsetof(siginfo_t, si_value) != 0x18);
96 9309 : BUILD_BUG_ON(offsetof(compat_siginfo_t, si_pid) != 0x0C);
97 9309 : BUILD_BUG_ON(offsetof(compat_siginfo_t, si_uid) != 0x10);
98 9309 : BUILD_BUG_ON(offsetof(compat_siginfo_t, si_value) != 0x14);
99 :
100 9309 : CHECK_CSI_OFFSET(_sigchld);
101 9309 : CHECK_CSI_SIZE (_sigchld, 5*sizeof(int));
102 9309 : CHECK_SI_SIZE (_sigchld, 8*sizeof(int));
103 :
104 9309 : BUILD_BUG_ON(offsetof(siginfo_t, si_pid) != 0x10);
105 9309 : BUILD_BUG_ON(offsetof(siginfo_t, si_uid) != 0x14);
106 9309 : BUILD_BUG_ON(offsetof(siginfo_t, si_status) != 0x18);
107 9309 : BUILD_BUG_ON(offsetof(siginfo_t, si_utime) != 0x20);
108 9309 : BUILD_BUG_ON(offsetof(siginfo_t, si_stime) != 0x28);
109 9309 : BUILD_BUG_ON(offsetof(compat_siginfo_t, si_pid) != 0x0C);
110 9309 : BUILD_BUG_ON(offsetof(compat_siginfo_t, si_uid) != 0x10);
111 9309 : BUILD_BUG_ON(offsetof(compat_siginfo_t, si_status) != 0x14);
112 9309 : BUILD_BUG_ON(offsetof(compat_siginfo_t, si_utime) != 0x18);
113 9309 : BUILD_BUG_ON(offsetof(compat_siginfo_t, si_stime) != 0x1C);
114 :
115 : #ifdef CONFIG_X86_X32_ABI
116 : CHECK_CSI_OFFSET(_sigchld_x32);
117 : CHECK_CSI_SIZE (_sigchld_x32, 7*sizeof(int));
118 : /* no _sigchld_x32 in the generic siginfo_t */
119 : BUILD_BUG_ON(offsetof(compat_siginfo_t, _sifields._sigchld_x32._utime) != 0x18);
120 : BUILD_BUG_ON(offsetof(compat_siginfo_t, _sifields._sigchld_x32._stime) != 0x20);
121 : #endif
122 :
123 9309 : CHECK_CSI_OFFSET(_sigfault);
124 9309 : CHECK_CSI_SIZE (_sigfault, 4*sizeof(int));
125 9309 : CHECK_SI_SIZE (_sigfault, 8*sizeof(int));
126 :
127 9309 : BUILD_BUG_ON(offsetof(siginfo_t, si_addr) != 0x10);
128 9309 : BUILD_BUG_ON(offsetof(compat_siginfo_t, si_addr) != 0x0C);
129 :
130 9309 : BUILD_BUG_ON(offsetof(siginfo_t, si_addr_lsb) != 0x18);
131 9309 : BUILD_BUG_ON(offsetof(compat_siginfo_t, si_addr_lsb) != 0x10);
132 :
133 9309 : BUILD_BUG_ON(offsetof(siginfo_t, si_lower) != 0x20);
134 9309 : BUILD_BUG_ON(offsetof(siginfo_t, si_upper) != 0x28);
135 9309 : BUILD_BUG_ON(offsetof(compat_siginfo_t, si_lower) != 0x14);
136 9309 : BUILD_BUG_ON(offsetof(compat_siginfo_t, si_upper) != 0x18);
137 :
138 9309 : BUILD_BUG_ON(offsetof(siginfo_t, si_pkey) != 0x20);
139 9309 : BUILD_BUG_ON(offsetof(compat_siginfo_t, si_pkey) != 0x14);
140 :
141 9309 : CHECK_CSI_OFFSET(_sigpoll);
142 9309 : CHECK_CSI_SIZE (_sigpoll, 2*sizeof(int));
143 9309 : CHECK_SI_SIZE (_sigpoll, 4*sizeof(int));
144 :
145 9309 : BUILD_BUG_ON(offsetof(siginfo_t, si_band) != 0x10);
146 9309 : BUILD_BUG_ON(offsetof(siginfo_t, si_fd) != 0x18);
147 9309 : BUILD_BUG_ON(offsetof(compat_siginfo_t, si_band) != 0x0C);
148 9309 : BUILD_BUG_ON(offsetof(compat_siginfo_t, si_fd) != 0x10);
149 :
150 9309 : CHECK_CSI_OFFSET(_sigsys);
151 9309 : CHECK_CSI_SIZE (_sigsys, 3*sizeof(int));
152 9309 : CHECK_SI_SIZE (_sigsys, 4*sizeof(int));
153 :
154 9309 : BUILD_BUG_ON(offsetof(siginfo_t, si_call_addr) != 0x10);
155 9309 : BUILD_BUG_ON(offsetof(siginfo_t, si_syscall) != 0x18);
156 9309 : BUILD_BUG_ON(offsetof(siginfo_t, si_arch) != 0x1C);
157 9309 : BUILD_BUG_ON(offsetof(compat_siginfo_t, si_call_addr) != 0x0C);
158 9309 : BUILD_BUG_ON(offsetof(compat_siginfo_t, si_syscall) != 0x10);
159 9309 : BUILD_BUG_ON(offsetof(compat_siginfo_t, si_arch) != 0x14);
160 :
161 : /* any new si_fields should be added here */
162 : }
163 :
164 9309 : void sigaction_compat_abi(struct k_sigaction *act, struct k_sigaction *oact)
165 : {
166 9309 : signal_compat_build_tests();
167 :
168 9309 : if (!act)
169 : return;
170 :
171 6148 : if (in_ia32_syscall())
172 0 : act->sa.sa_flags |= SA_IA32_ABI;
173 : if (in_x32_syscall())
174 : act->sa.sa_flags |= SA_X32_ABI;
175 : }
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