Commit | Line | Data |
---|---|---|
262d96b0 JH |
1 | /* |
2 | * Copyright (C) 1991,1992 Linus Torvalds | |
3 | * Copyright (C) 2005-2012 Imagination Technologies Ltd. | |
4 | * | |
5 | * 1997-11-28 Modified for POSIX.1b signals by Richard Henderson | |
6 | * | |
7 | */ | |
8 | ||
9 | #include <linux/sched.h> | |
10 | #include <linux/mm.h> | |
11 | #include <linux/smp.h> | |
12 | #include <linux/kernel.h> | |
13 | #include <linux/signal.h> | |
14 | #include <linux/errno.h> | |
15 | #include <linux/wait.h> | |
16 | #include <linux/ptrace.h> | |
17 | #include <linux/unistd.h> | |
18 | #include <linux/stddef.h> | |
19 | #include <linux/personality.h> | |
20 | #include <linux/uaccess.h> | |
21 | #include <linux/tracehook.h> | |
22 | ||
23 | #include <asm/ucontext.h> | |
24 | #include <asm/cacheflush.h> | |
25 | #include <asm/switch.h> | |
26 | #include <asm/syscall.h> | |
27 | #include <asm/syscalls.h> | |
28 | ||
29 | #define REG_FLAGS ctx.SaveMask | |
30 | #define REG_RETVAL ctx.DX[0].U0 | |
31 | #define REG_SYSCALL ctx.DX[0].U1 | |
32 | #define REG_SP ctx.AX[0].U0 | |
33 | #define REG_ARG1 ctx.DX[3].U1 | |
34 | #define REG_ARG2 ctx.DX[3].U0 | |
35 | #define REG_ARG3 ctx.DX[2].U1 | |
36 | #define REG_PC ctx.CurrPC | |
37 | #define REG_RTP ctx.DX[4].U1 | |
38 | ||
39 | struct rt_sigframe { | |
40 | struct siginfo info; | |
41 | struct ucontext uc; | |
42 | unsigned long retcode[2]; | |
43 | }; | |
44 | ||
45 | static int restore_sigcontext(struct pt_regs *regs, | |
46 | struct sigcontext __user *sc) | |
47 | { | |
48 | int err; | |
49 | ||
50 | /* Always make any pending restarted system calls return -EINTR */ | |
51 | current_thread_info()->restart_block.fn = do_no_restart_syscall; | |
52 | ||
53 | err = metag_gp_regs_copyin(regs, 0, sizeof(struct user_gp_regs), NULL, | |
54 | &sc->regs); | |
55 | if (!err) | |
56 | err = metag_cb_regs_copyin(regs, 0, | |
57 | sizeof(struct user_cb_regs), NULL, | |
58 | &sc->cb); | |
59 | if (!err) | |
60 | err = metag_rp_state_copyin(regs, 0, | |
61 | sizeof(struct user_rp_state), NULL, | |
62 | &sc->rp); | |
63 | ||
64 | /* This is a user-mode context. */ | |
65 | regs->REG_FLAGS |= TBICTX_PRIV_BIT; | |
66 | ||
67 | return err; | |
68 | } | |
69 | ||
70 | long sys_rt_sigreturn(void) | |
71 | { | |
72 | /* NOTE - Meta stack goes UPWARDS - so we wind the stack back */ | |
73 | struct pt_regs *regs = current_pt_regs(); | |
74 | struct rt_sigframe __user *frame; | |
75 | sigset_t set; | |
76 | ||
77 | frame = (__force struct rt_sigframe __user *)(regs->REG_SP - | |
78 | sizeof(*frame)); | |
79 | ||
80 | if (!access_ok(VERIFY_READ, frame, sizeof(*frame))) | |
81 | goto badframe; | |
82 | ||
83 | if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set))) | |
84 | goto badframe; | |
85 | ||
86 | set_current_blocked(&set); | |
87 | ||
88 | if (restore_sigcontext(regs, &frame->uc.uc_mcontext)) | |
89 | goto badframe; | |
90 | ||
91 | if (restore_altstack(&frame->uc.uc_stack)) | |
92 | goto badframe; | |
93 | ||
94 | return regs->REG_RETVAL; | |
95 | ||
96 | badframe: | |
97 | force_sig(SIGSEGV, current); | |
98 | ||
99 | return 0; | |
100 | } | |
101 | ||
102 | static int setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs, | |
103 | unsigned long mask) | |
104 | { | |
105 | int err; | |
106 | ||
107 | err = metag_gp_regs_copyout(regs, 0, sizeof(struct user_gp_regs), NULL, | |
108 | &sc->regs); | |
109 | ||
110 | if (!err) | |
111 | err = metag_cb_regs_copyout(regs, 0, | |
112 | sizeof(struct user_cb_regs), NULL, | |
113 | &sc->cb); | |
114 | if (!err) | |
115 | err = metag_rp_state_copyout(regs, 0, | |
116 | sizeof(struct user_rp_state), NULL, | |
117 | &sc->rp); | |
118 | ||
119 | /* OK, clear that cbuf flag in the old context, or our stored | |
120 | * catch buffer will be restored when we go to call the signal | |
121 | * handler. Also clear out the CBRP RA/RD pipe bit incase | |
122 | * that is pending as well! | |
123 | * Note that as we have already stored this context, these | |
124 | * flags will get restored on sigreturn to their original | |
125 | * state. | |
126 | */ | |
127 | regs->REG_FLAGS &= ~(TBICTX_XCBF_BIT | TBICTX_CBUF_BIT | | |
128 | TBICTX_CBRP_BIT); | |
129 | ||
130 | /* Clear out the LSM_STEP bits in case we are in the middle of | |
131 | * and MSET/MGET. | |
132 | */ | |
133 | regs->ctx.Flags &= ~TXSTATUS_LSM_STEP_BITS; | |
134 | ||
135 | err |= __put_user(mask, &sc->oldmask); | |
136 | ||
137 | return err; | |
138 | } | |
139 | ||
140 | /* | |
141 | * Determine which stack to use.. | |
142 | */ | |
d83961b7 | 143 | static void __user *get_sigframe(struct ksignal *ksig, unsigned long sp) |
262d96b0 | 144 | { |
d83961b7 | 145 | sp = sigsp(sp, ksig); |
262d96b0 JH |
146 | sp = (sp + 7) & ~7; /* 8byte align stack */ |
147 | ||
148 | return (void __user *)sp; | |
149 | } | |
150 | ||
d3c7e511 RW |
151 | static int setup_rt_frame(struct ksignal *ksig, sigset_t *set, |
152 | struct pt_regs *regs) | |
262d96b0 JH |
153 | { |
154 | struct rt_sigframe __user *frame; | |
d3c7e511 | 155 | int err; |
262d96b0 JH |
156 | unsigned long code; |
157 | ||
d83961b7 | 158 | frame = get_sigframe(ksig, regs->REG_SP); |
262d96b0 | 159 | if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) |
d3c7e511 | 160 | return -EFAULT; |
262d96b0 | 161 | |
d3c7e511 | 162 | err = copy_siginfo_to_user(&frame->info, &ksig->info); |
262d96b0 JH |
163 | |
164 | /* Create the ucontext. */ | |
165 | err |= __put_user(0, &frame->uc.uc_flags); | |
166 | err |= __put_user(0, (unsigned long __user *)&frame->uc.uc_link); | |
167 | err |= __save_altstack(&frame->uc.uc_stack, regs->REG_SP); | |
168 | err |= setup_sigcontext(&frame->uc.uc_mcontext, | |
169 | regs, set->sig[0]); | |
170 | err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set)); | |
171 | ||
172 | if (err) | |
d3c7e511 | 173 | return -EFAULT; |
262d96b0 JH |
174 | |
175 | /* Set up to return from userspace. */ | |
176 | ||
177 | /* MOV D1Re0 (D1.0), #__NR_rt_sigreturn */ | |
178 | code = 0x03000004 | (__NR_rt_sigreturn << 3); | |
179 | err |= __put_user(code, (unsigned long __user *)(&frame->retcode[0])); | |
180 | ||
181 | /* SWITCH #__METAG_SW_SYS */ | |
182 | code = __METAG_SW_ENCODING(SYS); | |
183 | err |= __put_user(code, (unsigned long __user *)(&frame->retcode[1])); | |
184 | ||
185 | if (err) | |
d3c7e511 | 186 | return -EFAULT; |
262d96b0 JH |
187 | |
188 | /* Set up registers for signal handler */ | |
189 | regs->REG_RTP = (unsigned long) frame->retcode; | |
190 | regs->REG_SP = (unsigned long) frame + sizeof(*frame); | |
d3c7e511 | 191 | regs->REG_ARG1 = ksig->sig; |
262d96b0 JH |
192 | regs->REG_ARG2 = (unsigned long) &frame->info; |
193 | regs->REG_ARG3 = (unsigned long) &frame->uc; | |
d3c7e511 | 194 | regs->REG_PC = (unsigned long) ksig->ka.sa.sa_handler; |
262d96b0 JH |
195 | |
196 | pr_debug("SIG deliver (%s:%d): sp=%p pc=%08x pr=%08x\n", | |
197 | current->comm, current->pid, frame, regs->REG_PC, | |
198 | regs->REG_RTP); | |
199 | ||
200 | /* Now pass size of 'new code' into sigtramp so we can do a more | |
201 | * effective cache flush - directed rather than 'full flush'. | |
202 | */ | |
203 | flush_cache_sigtramp(regs->REG_RTP, sizeof(frame->retcode)); | |
d3c7e511 | 204 | |
262d96b0 JH |
205 | return 0; |
206 | } | |
207 | ||
d3c7e511 | 208 | static void handle_signal(struct ksignal *ksig, struct pt_regs *regs) |
262d96b0 JH |
209 | { |
210 | sigset_t *oldset = sigmask_to_save(); | |
d3c7e511 | 211 | int ret; |
262d96b0 JH |
212 | |
213 | /* Set up the stack frame */ | |
d3c7e511 | 214 | ret = setup_rt_frame(ksig, oldset, regs); |
262d96b0 | 215 | |
d3c7e511 | 216 | signal_setup_done(ret, ksig, test_thread_flag(TIF_SINGLESTEP)); |
262d96b0 JH |
217 | } |
218 | ||
219 | /* | |
220 | * Notes for Meta. | |
221 | * We have moved from the old 2.4.9 SH way of using syscall_nr (in the stored | |
222 | * context) to passing in the syscall flag on the stack. | |
223 | * This is because having syscall_nr in our context does not fit with TBX, and | |
224 | * corrupted the stack. | |
225 | */ | |
226 | static int do_signal(struct pt_regs *regs, int syscall) | |
227 | { | |
228 | unsigned int retval = 0, continue_addr = 0, restart_addr = 0; | |
262d96b0 | 229 | int restart = 0; |
d3c7e511 | 230 | struct ksignal ksig; |
262d96b0 JH |
231 | |
232 | /* | |
233 | * By the end of rt_sigreturn the context describes the point that the | |
234 | * signal was taken (which may happen to be just before a syscall if | |
235 | * it's already been restarted). This should *never* be mistaken for a | |
236 | * system call in need of restarting. | |
237 | */ | |
238 | if (syscall == __NR_rt_sigreturn) | |
239 | syscall = -1; | |
240 | ||
241 | /* Did we come from a system call? */ | |
242 | if (syscall >= 0) { | |
243 | continue_addr = regs->REG_PC; | |
244 | restart_addr = continue_addr - 4; | |
245 | retval = regs->REG_RETVAL; | |
246 | ||
247 | /* | |
248 | * Prepare for system call restart. We do this here so that a | |
249 | * debugger will see the already changed PC. | |
250 | */ | |
251 | switch (retval) { | |
252 | case -ERESTART_RESTARTBLOCK: | |
253 | restart = -2; | |
254 | case -ERESTARTNOHAND: | |
255 | case -ERESTARTSYS: | |
256 | case -ERESTARTNOINTR: | |
257 | ++restart; | |
258 | regs->REG_PC = restart_addr; | |
259 | break; | |
260 | } | |
261 | } | |
262 | ||
263 | /* | |
264 | * Get the signal to deliver. When running under ptrace, at this point | |
265 | * the debugger may change all our registers ... | |
266 | */ | |
d3c7e511 RW |
267 | get_signal(&ksig); |
268 | ||
262d96b0 JH |
269 | /* |
270 | * Depending on the signal settings we may need to revert the decision | |
271 | * to restart the system call. But skip this if a debugger has chosen to | |
272 | * restart at a different PC. | |
273 | */ | |
274 | if (regs->REG_PC != restart_addr) | |
275 | restart = 0; | |
d3c7e511 | 276 | if (ksig.sig > 0) { |
262d96b0 JH |
277 | if (unlikely(restart)) { |
278 | if (retval == -ERESTARTNOHAND | |
279 | || retval == -ERESTART_RESTARTBLOCK | |
280 | || (retval == -ERESTARTSYS | |
d3c7e511 | 281 | && !(ksig.ka.sa.sa_flags & SA_RESTART))) { |
262d96b0 JH |
282 | regs->REG_RETVAL = -EINTR; |
283 | regs->REG_PC = continue_addr; | |
284 | } | |
285 | } | |
286 | ||
287 | /* Whee! Actually deliver the signal. */ | |
d3c7e511 | 288 | handle_signal(&ksig, regs); |
262d96b0 JH |
289 | return 0; |
290 | } | |
291 | ||
292 | /* Handlerless -ERESTART_RESTARTBLOCK re-enters via restart_syscall */ | |
293 | if (unlikely(restart < 0)) | |
294 | regs->REG_SYSCALL = __NR_restart_syscall; | |
295 | ||
296 | /* | |
297 | * If there's no signal to deliver, we just put the saved sigmask back. | |
298 | */ | |
299 | restore_saved_sigmask(); | |
300 | ||
301 | return restart; | |
302 | } | |
303 | ||
304 | int do_work_pending(struct pt_regs *regs, unsigned int thread_flags, | |
305 | int syscall) | |
306 | { | |
307 | do { | |
308 | if (likely(thread_flags & _TIF_NEED_RESCHED)) { | |
309 | schedule(); | |
310 | } else { | |
311 | if (unlikely(!user_mode(regs))) | |
312 | return 0; | |
313 | local_irq_enable(); | |
314 | if (thread_flags & _TIF_SIGPENDING) { | |
315 | int restart = do_signal(regs, syscall); | |
316 | if (unlikely(restart)) { | |
317 | /* | |
318 | * Restart without handlers. | |
319 | * Deal with it without leaving | |
320 | * the kernel space. | |
321 | */ | |
322 | return restart; | |
323 | } | |
324 | syscall = -1; | |
325 | } else { | |
326 | clear_thread_flag(TIF_NOTIFY_RESUME); | |
327 | tracehook_notify_resume(regs); | |
328 | } | |
329 | } | |
330 | local_irq_disable(); | |
331 | thread_flags = current_thread_info()->flags; | |
332 | } while (thread_flags & _TIF_WORK_MASK); | |
333 | return 0; | |
334 | } |