Commit | Line | Data |
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1394f032 | 1 | /* |
e8f263df | 2 | * Copyright 2004-2010 Analog Devices Inc. |
1394f032 | 3 | * |
96f1050d | 4 | * Licensed under the GPL-2 or later |
1394f032 BW |
5 | */ |
6 | ||
7 | #include <linux/signal.h> | |
8 | #include <linux/syscalls.h> | |
9 | #include <linux/ptrace.h> | |
10 | #include <linux/tty.h> | |
11 | #include <linux/personality.h> | |
12 | #include <linux/binfmts.h> | |
1f83b8f1 | 13 | #include <linux/uaccess.h> |
d1be2e48 | 14 | #include <linux/tracehook.h> |
1394f032 | 15 | |
1394f032 BW |
16 | #include <asm/cacheflush.h> |
17 | #include <asm/ucontext.h> | |
697a9d65 | 18 | #include <asm/fixed_code.h> |
ddaebcab | 19 | #include <asm/syscall.h> |
1394f032 | 20 | |
8513c42e BS |
21 | /* Location of the trace bit in SYSCFG. */ |
22 | #define TRACE_BITS 0x0001 | |
23 | ||
1394f032 BW |
24 | struct fdpic_func_descriptor { |
25 | unsigned long text; | |
26 | unsigned long GOT; | |
27 | }; | |
28 | ||
29 | struct rt_sigframe { | |
30 | int sig; | |
31 | struct siginfo *pinfo; | |
32 | void *puc; | |
697a9d65 BS |
33 | /* This is no longer needed by the kernel, but unfortunately userspace |
34 | * code expects it to be there. */ | |
1394f032 BW |
35 | char retcode[8]; |
36 | struct siginfo info; | |
37 | struct ucontext uc; | |
38 | }; | |
39 | ||
1394f032 | 40 | static inline int |
0ddeeca2 | 41 | rt_restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc, int *pr0) |
1394f032 BW |
42 | { |
43 | unsigned long usp = 0; | |
44 | int err = 0; | |
45 | ||
ddaebcab | 46 | /* Always make any pending restarted system calls return -EINTR */ |
f56141e3 | 47 | current->restart_block.fn = do_no_restart_syscall; |
ddaebcab | 48 | |
1394f032 BW |
49 | #define RESTORE(x) err |= __get_user(regs->x, &sc->sc_##x) |
50 | ||
51 | /* restore passed registers */ | |
52 | RESTORE(r0); RESTORE(r1); RESTORE(r2); RESTORE(r3); | |
53 | RESTORE(r4); RESTORE(r5); RESTORE(r6); RESTORE(r7); | |
54 | RESTORE(p0); RESTORE(p1); RESTORE(p2); RESTORE(p3); | |
55 | RESTORE(p4); RESTORE(p5); | |
56 | err |= __get_user(usp, &sc->sc_usp); | |
57 | wrusp(usp); | |
58 | RESTORE(a0w); RESTORE(a1w); | |
59 | RESTORE(a0x); RESTORE(a1x); | |
60 | RESTORE(astat); | |
61 | RESTORE(rets); | |
62 | RESTORE(pc); | |
63 | RESTORE(retx); | |
64 | RESTORE(fp); | |
65 | RESTORE(i0); RESTORE(i1); RESTORE(i2); RESTORE(i3); | |
66 | RESTORE(m0); RESTORE(m1); RESTORE(m2); RESTORE(m3); | |
67 | RESTORE(l0); RESTORE(l1); RESTORE(l2); RESTORE(l3); | |
68 | RESTORE(b0); RESTORE(b1); RESTORE(b2); RESTORE(b3); | |
69 | RESTORE(lc0); RESTORE(lc1); | |
70 | RESTORE(lt0); RESTORE(lt1); | |
71 | RESTORE(lb0); RESTORE(lb1); | |
72 | RESTORE(seqstat); | |
73 | ||
74 | regs->orig_p0 = -1; /* disable syscall checks */ | |
75 | ||
76 | *pr0 = regs->r0; | |
77 | return err; | |
78 | } | |
79 | ||
135c37b8 | 80 | asmlinkage int sys_rt_sigreturn(void) |
1394f032 | 81 | { |
135c37b8 | 82 | struct pt_regs *regs = current_pt_regs(); |
1394f032 BW |
83 | unsigned long usp = rdusp(); |
84 | struct rt_sigframe *frame = (struct rt_sigframe *)(usp); | |
85 | sigset_t set; | |
86 | int r0; | |
87 | ||
88 | if (!access_ok(VERIFY_READ, frame, sizeof(*frame))) | |
89 | goto badframe; | |
90 | if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set))) | |
91 | goto badframe; | |
92 | ||
8e3f9f65 | 93 | set_current_blocked(&set); |
1394f032 BW |
94 | |
95 | if (rt_restore_sigcontext(regs, &frame->uc.uc_mcontext, &r0)) | |
96 | goto badframe; | |
97 | ||
79d43210 | 98 | if (restore_altstack(&frame->uc.uc_stack)) |
1394f032 BW |
99 | goto badframe; |
100 | ||
101 | return r0; | |
102 | ||
1f83b8f1 | 103 | badframe: |
1394f032 BW |
104 | force_sig(SIGSEGV, current); |
105 | return 0; | |
106 | } | |
107 | ||
108 | static inline int rt_setup_sigcontext(struct sigcontext *sc, struct pt_regs *regs) | |
109 | { | |
110 | int err = 0; | |
111 | ||
112 | #define SETUP(x) err |= __put_user(regs->x, &sc->sc_##x) | |
113 | ||
114 | SETUP(r0); SETUP(r1); SETUP(r2); SETUP(r3); | |
115 | SETUP(r4); SETUP(r5); SETUP(r6); SETUP(r7); | |
116 | SETUP(p0); SETUP(p1); SETUP(p2); SETUP(p3); | |
117 | SETUP(p4); SETUP(p5); | |
118 | err |= __put_user(rdusp(), &sc->sc_usp); | |
119 | SETUP(a0w); SETUP(a1w); | |
120 | SETUP(a0x); SETUP(a1x); | |
121 | SETUP(astat); | |
122 | SETUP(rets); | |
123 | SETUP(pc); | |
124 | SETUP(retx); | |
125 | SETUP(fp); | |
126 | SETUP(i0); SETUP(i1); SETUP(i2); SETUP(i3); | |
127 | SETUP(m0); SETUP(m1); SETUP(m2); SETUP(m3); | |
128 | SETUP(l0); SETUP(l1); SETUP(l2); SETUP(l3); | |
129 | SETUP(b0); SETUP(b1); SETUP(b2); SETUP(b3); | |
130 | SETUP(lc0); SETUP(lc1); | |
131 | SETUP(lt0); SETUP(lt1); | |
132 | SETUP(lb0); SETUP(lb1); | |
133 | SETUP(seqstat); | |
134 | ||
135 | return err; | |
136 | } | |
137 | ||
e90670a9 | 138 | static inline void *get_sigframe(struct ksignal *ksig, |
1394f032 BW |
139 | size_t frame_size) |
140 | { | |
e90670a9 | 141 | unsigned long usp = sigsp(rdusp(), ksig); |
1394f032 | 142 | |
1394f032 BW |
143 | return (void *)((usp - frame_size) & -8UL); |
144 | } | |
145 | ||
146 | static int | |
1270cff1 | 147 | setup_rt_frame(struct ksignal *ksig, sigset_t *set, struct pt_regs *regs) |
1394f032 BW |
148 | { |
149 | struct rt_sigframe *frame; | |
150 | int err = 0; | |
151 | ||
e90670a9 | 152 | frame = get_sigframe(ksig, sizeof(*frame)); |
1394f032 | 153 | |
7bd83010 | 154 | err |= __put_user(ksig->sig, &frame->sig); |
1394f032 BW |
155 | |
156 | err |= __put_user(&frame->info, &frame->pinfo); | |
157 | err |= __put_user(&frame->uc, &frame->puc); | |
1270cff1 | 158 | err |= copy_siginfo_to_user(&frame->info, &ksig->info); |
1394f032 BW |
159 | |
160 | /* Create the ucontext. */ | |
161 | err |= __put_user(0, &frame->uc.uc_flags); | |
162 | err |= __put_user(0, &frame->uc.uc_link); | |
79d43210 | 163 | err |= __save_altstack(&frame->uc.uc_stack, rdusp()); |
1394f032 BW |
164 | err |= rt_setup_sigcontext(&frame->uc.uc_mcontext, regs); |
165 | err |= copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set)); | |
166 | ||
1394f032 | 167 | if (err) |
29bf5dd8 | 168 | return -EFAULT; |
1394f032 | 169 | |
1394f032 | 170 | /* Set up registers for signal handler */ |
ecd0fa98 | 171 | if (current->personality & FDPIC_FUNCPTRS) { |
1394f032 | 172 | struct fdpic_func_descriptor __user *funcptr = |
1270cff1 | 173 | (struct fdpic_func_descriptor *) ksig->ka.sa.sa_handler; |
29bf5dd8 AV |
174 | u32 pc, p3; |
175 | err |= __get_user(pc, &funcptr->text); | |
176 | err |= __get_user(p3, &funcptr->GOT); | |
177 | if (err) | |
178 | return -EFAULT; | |
179 | regs->pc = pc; | |
180 | regs->p3 = p3; | |
1394f032 | 181 | } else |
1270cff1 | 182 | regs->pc = (unsigned long)ksig->ka.sa.sa_handler; |
29bf5dd8 | 183 | wrusp((unsigned long)frame); |
697a9d65 | 184 | regs->rets = SIGRETURN_STUB; |
1394f032 BW |
185 | |
186 | regs->r0 = frame->sig; | |
187 | regs->r1 = (unsigned long)(&frame->info); | |
188 | regs->r2 = (unsigned long)(&frame->uc); | |
189 | ||
190 | return 0; | |
1394f032 BW |
191 | } |
192 | ||
193 | static inline void | |
194 | handle_restart(struct pt_regs *regs, struct k_sigaction *ka, int has_handler) | |
195 | { | |
196 | switch (regs->r0) { | |
197 | case -ERESTARTNOHAND: | |
198 | if (!has_handler) | |
199 | goto do_restart; | |
200 | regs->r0 = -EINTR; | |
201 | break; | |
202 | ||
203 | case -ERESTARTSYS: | |
204 | if (has_handler && !(ka->sa.sa_flags & SA_RESTART)) { | |
205 | regs->r0 = -EINTR; | |
206 | break; | |
207 | } | |
208 | /* fallthrough */ | |
209 | case -ERESTARTNOINTR: | |
1f83b8f1 | 210 | do_restart: |
1394f032 BW |
211 | regs->p0 = regs->orig_p0; |
212 | regs->r0 = regs->orig_r0; | |
213 | regs->pc -= 2; | |
214 | break; | |
ddaebcab MF |
215 | |
216 | case -ERESTART_RESTARTBLOCK: | |
217 | regs->p0 = __NR_restart_syscall; | |
218 | regs->pc -= 2; | |
219 | break; | |
1394f032 BW |
220 | } |
221 | } | |
222 | ||
223 | /* | |
224 | * OK, we're invoking a handler | |
225 | */ | |
a610d6e6 | 226 | static void |
1270cff1 | 227 | handle_signal(struct ksignal *ksig, struct pt_regs *regs) |
1394f032 | 228 | { |
1270cff1 RW |
229 | int ret; |
230 | ||
1394f032 BW |
231 | /* are we from a system call? to see pt_regs->orig_p0 */ |
232 | if (regs->orig_p0 >= 0) | |
233 | /* If so, check system call restarting.. */ | |
1270cff1 | 234 | handle_restart(regs, &ksig->ka, 1); |
1394f032 BW |
235 | |
236 | /* set up the stack frame */ | |
1270cff1 RW |
237 | ret = setup_rt_frame(ksig, sigmask_to_save(), regs); |
238 | ||
239 | signal_setup_done(ret, ksig, test_thread_flag(TIF_SINGLESTEP)); | |
1394f032 BW |
240 | } |
241 | ||
242 | /* | |
243 | * Note that 'init' is a special process: it doesn't get signals it doesn't | |
244 | * want to handle. Thus you cannot kill init even with a SIGKILL even by | |
245 | * mistake. | |
246 | * | |
247 | * Note that we go through the signals twice: once to check the signals | |
248 | * that the kernel can handle, and then we build all the user-level signal | |
249 | * handling stack-frames in one go after that. | |
250 | */ | |
251 | asmlinkage void do_signal(struct pt_regs *regs) | |
252 | { | |
1270cff1 | 253 | struct ksignal ksig; |
1394f032 BW |
254 | |
255 | current->thread.esp0 = (unsigned long)regs; | |
256 | ||
1270cff1 | 257 | if (get_signal(&ksig)) { |
1394f032 | 258 | /* Whee! Actually deliver the signal. */ |
1270cff1 | 259 | handle_signal(&ksig, regs); |
1394f032 BW |
260 | return; |
261 | } | |
262 | ||
1394f032 BW |
263 | /* Did we come from a system call? */ |
264 | if (regs->orig_p0 >= 0) | |
265 | /* Restart the system call - no handlers present */ | |
266 | handle_restart(regs, NULL, 0); | |
267 | ||
268 | /* if there's no signal to deliver, we just put the saved sigmask | |
269 | * back */ | |
51a7b448 | 270 | restore_saved_sigmask(); |
1394f032 | 271 | } |
d1be2e48 BS |
272 | |
273 | /* | |
274 | * notification of userspace execution resumption | |
275 | */ | |
276 | asmlinkage void do_notify_resume(struct pt_regs *regs) | |
277 | { | |
6fd84c08 | 278 | if (test_thread_flag(TIF_SIGPENDING)) |
d1be2e48 BS |
279 | do_signal(regs); |
280 | ||
281 | if (test_thread_flag(TIF_NOTIFY_RESUME)) { | |
282 | clear_thread_flag(TIF_NOTIFY_RESUME); | |
283 | tracehook_notify_resume(regs); | |
d1be2e48 BS |
284 | } |
285 | } | |
286 |