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867e359b CM |
1 | /* |
2 | * Copyright 2010 Tilera Corporation. All Rights Reserved. | |
3 | * | |
4 | * This program is free software; you can redistribute it and/or | |
5 | * modify it under the terms of the GNU General Public License | |
6 | * as published by the Free Software Foundation, version 2. | |
7 | * | |
8 | * This program is distributed in the hope that it will be useful, but | |
9 | * WITHOUT ANY WARRANTY; without even the implied warranty of | |
10 | * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or | |
11 | * NON INFRINGEMENT. See the GNU General Public License for | |
12 | * more details. | |
13 | */ | |
14 | ||
15 | #include <linux/sched.h> | |
16 | #include <linux/mm.h> | |
17 | #include <linux/smp.h> | |
867e359b CM |
18 | #include <linux/kernel.h> |
19 | #include <linux/signal.h> | |
20 | #include <linux/errno.h> | |
21 | #include <linux/wait.h> | |
22 | #include <linux/unistd.h> | |
23 | #include <linux/stddef.h> | |
24 | #include <linux/personality.h> | |
25 | #include <linux/suspend.h> | |
26 | #include <linux/ptrace.h> | |
27 | #include <linux/elf.h> | |
28 | #include <linux/compat.h> | |
29 | #include <linux/syscalls.h> | |
30 | #include <linux/uaccess.h> | |
31 | #include <asm/processor.h> | |
32 | #include <asm/ucontext.h> | |
33 | #include <asm/sigframe.h> | |
0707ad30 | 34 | #include <asm/syscalls.h> |
4a556f4f | 35 | #include <asm/vdso.h> |
867e359b CM |
36 | #include <arch/interrupts.h> |
37 | ||
867e359b CM |
38 | struct compat_ucontext { |
39 | compat_ulong_t uc_flags; | |
40 | compat_uptr_t uc_link; | |
41 | struct compat_sigaltstack uc_stack; | |
42 | struct sigcontext uc_mcontext; | |
43 | sigset_t uc_sigmask; /* mask last for extensibility */ | |
44 | }; | |
45 | ||
867e359b CM |
46 | struct compat_rt_sigframe { |
47 | unsigned char save_area[C_ABI_SAVE_AREA_SIZE]; /* caller save area */ | |
48 | struct compat_siginfo info; | |
49 | struct compat_ucontext uc; | |
50 | }; | |
51 | ||
ce395960 | 52 | int copy_siginfo_to_user32(struct compat_siginfo __user *to, const siginfo_t *from) |
867e359b CM |
53 | { |
54 | int err; | |
55 | ||
56 | if (!access_ok(VERIFY_WRITE, to, sizeof(struct compat_siginfo))) | |
57 | return -EFAULT; | |
58 | ||
59 | /* If you change siginfo_t structure, please make sure that | |
60 | this code is fixed accordingly. | |
61 | It should never copy any pad contained in the structure | |
62 | to avoid security leaks, but must copy the generic | |
63 | 3 ints plus the relevant union member. */ | |
64 | err = __put_user(from->si_signo, &to->si_signo); | |
65 | err |= __put_user(from->si_errno, &to->si_errno); | |
66 | err |= __put_user((short)from->si_code, &to->si_code); | |
67 | ||
68 | if (from->si_code < 0) { | |
69 | err |= __put_user(from->si_pid, &to->si_pid); | |
70 | err |= __put_user(from->si_uid, &to->si_uid); | |
89067c2d | 71 | err |= __put_user(from->si_int, &to->si_int); |
867e359b CM |
72 | } else { |
73 | /* | |
74 | * First 32bits of unions are always present: | |
75 | * si_pid === si_band === si_tid === si_addr(LS half) | |
76 | */ | |
77 | err |= __put_user(from->_sifields._pad[0], | |
78 | &to->_sifields._pad[0]); | |
79 | switch (from->si_code >> 16) { | |
80 | case __SI_FAULT >> 16: | |
81 | break; | |
82 | case __SI_CHLD >> 16: | |
83 | err |= __put_user(from->si_utime, &to->si_utime); | |
84 | err |= __put_user(from->si_stime, &to->si_stime); | |
85 | err |= __put_user(from->si_status, &to->si_status); | |
86 | /* FALL THROUGH */ | |
87 | default: | |
88 | case __SI_KILL >> 16: | |
89 | err |= __put_user(from->si_uid, &to->si_uid); | |
90 | break; | |
91 | case __SI_POLL >> 16: | |
92 | err |= __put_user(from->si_fd, &to->si_fd); | |
93 | break; | |
94 | case __SI_TIMER >> 16: | |
95 | err |= __put_user(from->si_overrun, &to->si_overrun); | |
89067c2d | 96 | err |= __put_user(from->si_int, &to->si_int); |
867e359b CM |
97 | break; |
98 | /* This is not generated by the kernel as of now. */ | |
99 | case __SI_RT >> 16: | |
100 | case __SI_MESGQ >> 16: | |
101 | err |= __put_user(from->si_uid, &to->si_uid); | |
102 | err |= __put_user(from->si_int, &to->si_int); | |
103 | break; | |
104 | } | |
105 | } | |
106 | return err; | |
107 | } | |
108 | ||
109 | int copy_siginfo_from_user32(siginfo_t *to, struct compat_siginfo __user *from) | |
110 | { | |
111 | int err; | |
867e359b CM |
112 | |
113 | if (!access_ok(VERIFY_READ, from, sizeof(struct compat_siginfo))) | |
114 | return -EFAULT; | |
115 | ||
116 | err = __get_user(to->si_signo, &from->si_signo); | |
117 | err |= __get_user(to->si_errno, &from->si_errno); | |
118 | err |= __get_user(to->si_code, &from->si_code); | |
119 | ||
120 | err |= __get_user(to->si_pid, &from->si_pid); | |
121 | err |= __get_user(to->si_uid, &from->si_uid); | |
89067c2d | 122 | err |= __get_user(to->si_int, &from->si_int); |
867e359b CM |
123 | |
124 | return err; | |
125 | } | |
126 | ||
81711cee | 127 | /* The assembly shim for this function arranges to ignore the return value. */ |
6b14e419 | 128 | long compat_sys_rt_sigreturn(void) |
867e359b | 129 | { |
6b14e419 | 130 | struct pt_regs *regs = current_pt_regs(); |
867e359b CM |
131 | struct compat_rt_sigframe __user *frame = |
132 | (struct compat_rt_sigframe __user *) compat_ptr(regs->sp); | |
133 | sigset_t set; | |
867e359b CM |
134 | |
135 | if (!access_ok(VERIFY_READ, frame, sizeof(*frame))) | |
136 | goto badframe; | |
137 | if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set))) | |
138 | goto badframe; | |
139 | ||
ad092338 | 140 | set_current_blocked(&set); |
867e359b | 141 | |
81711cee | 142 | if (restore_sigcontext(regs, &frame->uc.uc_mcontext)) |
867e359b CM |
143 | goto badframe; |
144 | ||
47669ab0 | 145 | if (compat_restore_altstack(&frame->uc.uc_stack)) |
867e359b CM |
146 | goto badframe; |
147 | ||
81711cee | 148 | return 0; |
867e359b CM |
149 | |
150 | badframe: | |
571d76ac | 151 | signal_fault("bad sigreturn frame", regs, frame, 0); |
867e359b CM |
152 | return 0; |
153 | } | |
154 | ||
155 | /* | |
156 | * Determine which stack to use.. | |
157 | */ | |
158 | static inline void __user *compat_get_sigframe(struct k_sigaction *ka, | |
159 | struct pt_regs *regs, | |
160 | size_t frame_size) | |
161 | { | |
162 | unsigned long sp; | |
163 | ||
164 | /* Default to using normal stack */ | |
165 | sp = (unsigned long)compat_ptr(regs->sp); | |
166 | ||
167 | /* | |
168 | * If we are on the alternate signal stack and would overflow | |
169 | * it, don't. Return an always-bogus address instead so we | |
170 | * will die with SIGSEGV. | |
171 | */ | |
172 | if (on_sig_stack(sp) && !likely(on_sig_stack(sp - frame_size))) | |
0707ad30 | 173 | return (void __user __force *)-1UL; |
867e359b CM |
174 | |
175 | /* This is the X/Open sanctioned signal stack switching. */ | |
176 | if (ka->sa.sa_flags & SA_ONSTACK) { | |
177 | if (sas_ss_flags(sp) == 0) | |
178 | sp = current->sas_ss_sp + current->sas_ss_size; | |
179 | } | |
180 | ||
181 | sp -= frame_size; | |
182 | /* | |
183 | * Align the stack pointer according to the TILE ABI, | |
184 | * i.e. so that on function entry (sp & 15) == 0. | |
185 | */ | |
186 | sp &= -16UL; | |
187 | return (void __user *) sp; | |
188 | } | |
189 | ||
b3707c7e RW |
190 | int compat_setup_rt_frame(struct ksignal *ksig, sigset_t *set, |
191 | struct pt_regs *regs) | |
867e359b CM |
192 | { |
193 | unsigned long restorer; | |
194 | struct compat_rt_sigframe __user *frame; | |
b3707c7e | 195 | int err = 0, sig = ksig->sig; |
867e359b | 196 | |
b3707c7e | 197 | frame = compat_get_sigframe(&ksig->ka, regs, sizeof(*frame)); |
867e359b CM |
198 | |
199 | if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) | |
b3707c7e | 200 | goto err; |
867e359b | 201 | |
867e359b | 202 | /* Always write at least the signal number for the stack backtracer. */ |
b3707c7e | 203 | if (ksig->ka.sa.sa_flags & SA_SIGINFO) { |
867e359b | 204 | /* At sigreturn time, restore the callee-save registers too. */ |
b3707c7e | 205 | err |= copy_siginfo_to_user32(&frame->info, &ksig->info); |
867e359b CM |
206 | regs->flags |= PT_FLAGS_RESTORE_REGS; |
207 | } else { | |
b3707c7e | 208 | err |= __put_user(ksig->info.si_signo, &frame->info.si_signo); |
867e359b CM |
209 | } |
210 | ||
211 | /* Create the ucontext. */ | |
212 | err |= __clear_user(&frame->save_area, sizeof(frame->save_area)); | |
213 | err |= __put_user(0, &frame->uc.uc_flags); | |
214 | err |= __put_user(0, &frame->uc.uc_link); | |
47669ab0 | 215 | err |= __compat_save_altstack(&frame->uc.uc_stack, regs->sp); |
867e359b CM |
216 | err |= setup_sigcontext(&frame->uc.uc_mcontext, regs); |
217 | err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set)); | |
218 | if (err) | |
b3707c7e | 219 | goto err; |
867e359b | 220 | |
4a556f4f | 221 | restorer = VDSO_SYM(&__vdso_rt_sigreturn); |
b3707c7e RW |
222 | if (ksig->ka.sa.sa_flags & SA_RESTORER) |
223 | restorer = ptr_to_compat_reg(ksig->ka.sa.sa_restorer); | |
867e359b CM |
224 | |
225 | /* | |
226 | * Set up registers for signal handler. | |
227 | * Registers that we don't modify keep the value they had from | |
228 | * user-space at the time we took the signal. | |
a134d228 CM |
229 | * We always pass siginfo and mcontext, regardless of SA_SIGINFO, |
230 | * since some things rely on this (e.g. glibc's debug/segfault.c). | |
867e359b | 231 | */ |
b3707c7e | 232 | regs->pc = ptr_to_compat_reg(ksig->ka.sa.sa_handler); |
867e359b CM |
233 | regs->ex1 = PL_ICS_EX1(USER_PL, 1); /* set crit sec in handler */ |
234 | regs->sp = ptr_to_compat_reg(frame); | |
235 | regs->lr = restorer; | |
89f191b3 | 236 | regs->regs[0] = (unsigned long) sig; |
a134d228 CM |
237 | regs->regs[1] = ptr_to_compat_reg(&frame->info); |
238 | regs->regs[2] = ptr_to_compat_reg(&frame->uc); | |
239 | regs->flags |= PT_FLAGS_CALLER_SAVES; | |
867e359b CM |
240 | return 0; |
241 | ||
b3707c7e RW |
242 | err: |
243 | trace_unhandled_signal("bad sigreturn frame", regs, | |
244 | (unsigned long)frame, SIGSEGV); | |
867e359b CM |
245 | return -EFAULT; |
246 | } |