Loading...
Note: File does not exist in v6.8.
1/*
2 * Port on Texas Instruments TMS320C6x architecture
3 *
4 * Copyright (C) 2004, 2006, 2009, 2010, 2011 Texas Instruments Incorporated
5 * Author: Aurelien Jacquiot (aurelien.jacquiot@jaluna.com)
6 *
7 * Updated for 2.6.34: Mark Salter <msalter@redhat.com>
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License version 2 as
11 * published by the Free Software Foundation.
12 */
13
14#include <linux/kernel.h>
15#include <linux/uaccess.h>
16#include <linux/syscalls.h>
17#include <linux/tracehook.h>
18
19#include <asm/ucontext.h>
20#include <asm/cacheflush.h>
21
22
23/*
24 * Do a signal return, undo the signal stack.
25 */
26
27#define RETCODE_SIZE (9 << 2) /* 9 instructions = 36 bytes */
28
29struct rt_sigframe {
30 struct siginfo __user *pinfo;
31 void __user *puc;
32 struct siginfo info;
33 struct ucontext uc;
34 unsigned long retcode[RETCODE_SIZE >> 2];
35};
36
37static int restore_sigcontext(struct pt_regs *regs,
38 struct sigcontext __user *sc)
39{
40 int err = 0;
41
42 /* The access_ok check was done by caller, so use __get_user here */
43#define COPY(x) (err |= __get_user(regs->x, &sc->sc_##x))
44
45 COPY(sp); COPY(a4); COPY(b4); COPY(a6); COPY(b6); COPY(a8); COPY(b8);
46 COPY(a0); COPY(a1); COPY(a2); COPY(a3); COPY(a5); COPY(a7); COPY(a9);
47 COPY(b0); COPY(b1); COPY(b2); COPY(b3); COPY(b5); COPY(b7); COPY(b9);
48
49 COPY(a16); COPY(a17); COPY(a18); COPY(a19);
50 COPY(a20); COPY(a21); COPY(a22); COPY(a23);
51 COPY(a24); COPY(a25); COPY(a26); COPY(a27);
52 COPY(a28); COPY(a29); COPY(a30); COPY(a31);
53 COPY(b16); COPY(b17); COPY(b18); COPY(b19);
54 COPY(b20); COPY(b21); COPY(b22); COPY(b23);
55 COPY(b24); COPY(b25); COPY(b26); COPY(b27);
56 COPY(b28); COPY(b29); COPY(b30); COPY(b31);
57
58 COPY(csr); COPY(pc);
59
60#undef COPY
61
62 return err;
63}
64
65asmlinkage int do_rt_sigreturn(struct pt_regs *regs)
66{
67 struct rt_sigframe __user *frame;
68 sigset_t set;
69
70 /* Always make any pending restarted system calls return -EINTR */
71 current_thread_info()->restart_block.fn = do_no_restart_syscall;
72
73 /*
74 * Since we stacked the signal on a dword boundary,
75 * 'sp' should be dword aligned here. If it's
76 * not, then the user is trying to mess with us.
77 */
78 if (regs->sp & 7)
79 goto badframe;
80
81 frame = (struct rt_sigframe __user *) ((unsigned long) regs->sp + 8);
82
83 if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
84 goto badframe;
85 if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
86 goto badframe;
87
88 set_current_blocked(&set);
89
90 if (restore_sigcontext(regs, &frame->uc.uc_mcontext))
91 goto badframe;
92
93 return regs->a4;
94
95badframe:
96 force_sig(SIGSEGV, current);
97 return 0;
98}
99
100static int setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs,
101 unsigned long mask)
102{
103 int err = 0;
104
105 err |= __put_user(mask, &sc->sc_mask);
106
107 /* The access_ok check was done by caller, so use __put_user here */
108#define COPY(x) (err |= __put_user(regs->x, &sc->sc_##x))
109
110 COPY(sp); COPY(a4); COPY(b4); COPY(a6); COPY(b6); COPY(a8); COPY(b8);
111 COPY(a0); COPY(a1); COPY(a2); COPY(a3); COPY(a5); COPY(a7); COPY(a9);
112 COPY(b0); COPY(b1); COPY(b2); COPY(b3); COPY(b5); COPY(b7); COPY(b9);
113
114 COPY(a16); COPY(a17); COPY(a18); COPY(a19);
115 COPY(a20); COPY(a21); COPY(a22); COPY(a23);
116 COPY(a24); COPY(a25); COPY(a26); COPY(a27);
117 COPY(a28); COPY(a29); COPY(a30); COPY(a31);
118 COPY(b16); COPY(b17); COPY(b18); COPY(b19);
119 COPY(b20); COPY(b21); COPY(b22); COPY(b23);
120 COPY(b24); COPY(b25); COPY(b26); COPY(b27);
121 COPY(b28); COPY(b29); COPY(b30); COPY(b31);
122
123 COPY(csr); COPY(pc);
124
125#undef COPY
126
127 return err;
128}
129
130static inline void __user *get_sigframe(struct k_sigaction *ka,
131 struct pt_regs *regs,
132 unsigned long framesize)
133{
134 unsigned long sp = regs->sp;
135
136 /*
137 * This is the X/Open sanctioned signal stack switching.
138 */
139 if ((ka->sa.sa_flags & SA_ONSTACK) && sas_ss_flags(sp) == 0)
140 sp = current->sas_ss_sp + current->sas_ss_size;
141
142 /*
143 * No matter what happens, 'sp' must be dword
144 * aligned. Otherwise, nasty things will happen
145 */
146 return (void __user *)((sp - framesize) & ~7);
147}
148
149static int setup_rt_frame(int signr, struct k_sigaction *ka, siginfo_t *info,
150 sigset_t *set, struct pt_regs *regs)
151{
152 struct rt_sigframe __user *frame;
153 unsigned long __user *retcode;
154 int err = 0;
155
156 frame = get_sigframe(ka, regs, sizeof(*frame));
157
158 if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
159 goto segv_and_exit;
160
161 err |= __put_user(&frame->info, &frame->pinfo);
162 err |= __put_user(&frame->uc, &frame->puc);
163 err |= copy_siginfo_to_user(&frame->info, info);
164
165 /* Clear all the bits of the ucontext we don't use. */
166 err |= __clear_user(&frame->uc, offsetof(struct ucontext, uc_mcontext));
167
168 err |= setup_sigcontext(&frame->uc.uc_mcontext, regs, set->sig[0]);
169 err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
170
171 /* Set up to return from userspace */
172 retcode = (unsigned long __user *) &frame->retcode;
173
174 /* The access_ok check was done above, so use __put_user here */
175#define COPY(x) (err |= __put_user(x, retcode++))
176
177 COPY(0x0000002AUL | (__NR_rt_sigreturn << 7));
178 /* MVK __NR_rt_sigreturn,B0 */
179 COPY(0x10000000UL); /* SWE */
180 COPY(0x00006000UL); /* NOP 4 */
181 COPY(0x00006000UL); /* NOP 4 */
182 COPY(0x00006000UL); /* NOP 4 */
183 COPY(0x00006000UL); /* NOP 4 */
184 COPY(0x00006000UL); /* NOP 4 */
185 COPY(0x00006000UL); /* NOP 4 */
186 COPY(0x00006000UL); /* NOP 4 */
187
188#undef COPY
189
190 if (err)
191 goto segv_and_exit;
192
193 flush_icache_range((unsigned long) &frame->retcode,
194 (unsigned long) &frame->retcode + RETCODE_SIZE);
195
196 retcode = (unsigned long __user *) &frame->retcode;
197
198 /* Change user context to branch to signal handler */
199 regs->sp = (unsigned long) frame - 8;
200 regs->b3 = (unsigned long) retcode;
201 regs->pc = (unsigned long) ka->sa.sa_handler;
202
203 /* Give the signal number to the handler */
204 regs->a4 = signr;
205
206 /*
207 * For realtime signals we must also set the second and third
208 * arguments for the signal handler.
209 * -- Peter Maydell <pmaydell@chiark.greenend.org.uk> 2000-12-06
210 */
211 regs->b4 = (unsigned long)&frame->info;
212 regs->a6 = (unsigned long)&frame->uc;
213
214 return 0;
215
216segv_and_exit:
217 force_sigsegv(signr, current);
218 return -EFAULT;
219}
220
221static inline void
222handle_restart(struct pt_regs *regs, struct k_sigaction *ka, int has_handler)
223{
224 switch (regs->a4) {
225 case -ERESTARTNOHAND:
226 if (!has_handler)
227 goto do_restart;
228 regs->a4 = -EINTR;
229 break;
230
231 case -ERESTARTSYS:
232 if (has_handler && !(ka->sa.sa_flags & SA_RESTART)) {
233 regs->a4 = -EINTR;
234 break;
235 }
236 /* fallthrough */
237 case -ERESTARTNOINTR:
238do_restart:
239 regs->a4 = regs->orig_a4;
240 regs->pc -= 4;
241 break;
242 }
243}
244
245/*
246 * handle the actual delivery of a signal to userspace
247 */
248static void handle_signal(int sig,
249 siginfo_t *info, struct k_sigaction *ka,
250 struct pt_regs *regs, int syscall)
251{
252 int ret;
253
254 /* Are we from a system call? */
255 if (syscall) {
256 /* If so, check system call restarting.. */
257 switch (regs->a4) {
258 case -ERESTART_RESTARTBLOCK:
259 case -ERESTARTNOHAND:
260 regs->a4 = -EINTR;
261 break;
262
263 case -ERESTARTSYS:
264 if (!(ka->sa.sa_flags & SA_RESTART)) {
265 regs->a4 = -EINTR;
266 break;
267 }
268
269 /* fallthrough */
270 case -ERESTARTNOINTR:
271 regs->a4 = regs->orig_a4;
272 regs->pc -= 4;
273 }
274 }
275
276 /* Set up the stack frame */
277 if (setup_rt_frame(sig, ka, info, sigmask_to_save(), regs) < 0)
278 return;
279 signal_delivered(sig, info, ka, regs, 0);
280}
281
282/*
283 * handle a potential signal
284 */
285static void do_signal(struct pt_regs *regs, int syscall)
286{
287 struct k_sigaction ka;
288 siginfo_t info;
289 int signr;
290
291 /* we want the common case to go fast, which is why we may in certain
292 * cases get here from kernel mode */
293 if (!user_mode(regs))
294 return;
295
296 signr = get_signal_to_deliver(&info, &ka, regs, NULL);
297 if (signr > 0) {
298 handle_signal(signr, &info, &ka, regs, syscall);
299 return;
300 }
301
302 /* did we come from a system call? */
303 if (syscall) {
304 /* restart the system call - no handlers present */
305 switch (regs->a4) {
306 case -ERESTARTNOHAND:
307 case -ERESTARTSYS:
308 case -ERESTARTNOINTR:
309 regs->a4 = regs->orig_a4;
310 regs->pc -= 4;
311 break;
312
313 case -ERESTART_RESTARTBLOCK:
314 regs->a4 = regs->orig_a4;
315 regs->b0 = __NR_restart_syscall;
316 regs->pc -= 4;
317 break;
318 }
319 }
320
321 /* if there's no signal to deliver, we just put the saved sigmask
322 * back */
323 restore_saved_sigmask();
324}
325
326/*
327 * notification of userspace execution resumption
328 * - triggered by current->work.notify_resume
329 */
330asmlinkage void do_notify_resume(struct pt_regs *regs, u32 thread_info_flags,
331 int syscall)
332{
333 /* deal with pending signal delivery */
334 if (thread_info_flags & (1 << TIF_SIGPENDING))
335 do_signal(regs, syscall);
336
337 if (thread_info_flags & (1 << TIF_NOTIFY_RESUME)) {
338 clear_thread_flag(TIF_NOTIFY_RESUME);
339 tracehook_notify_resume(regs);
340 }
341}