]>
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> | |
68db0cf1 | 10 | #include <linux/sched/task_stack.h> |
262d96b0 JH |
11 | #include <linux/mm.h> |
12 | #include <linux/smp.h> | |
13 | #include <linux/kernel.h> | |
14 | #include <linux/signal.h> | |
15 | #include <linux/errno.h> | |
16 | #include <linux/wait.h> | |
17 | #include <linux/ptrace.h> | |
18 | #include <linux/unistd.h> | |
19 | #include <linux/stddef.h> | |
20 | #include <linux/personality.h> | |
21 | #include <linux/uaccess.h> | |
22 | #include <linux/tracehook.h> | |
23 | ||
24 | #include <asm/ucontext.h> | |
25 | #include <asm/cacheflush.h> | |
26 | #include <asm/switch.h> | |
27 | #include <asm/syscall.h> | |
28 | #include <asm/syscalls.h> | |
29 | ||
30 | #define REG_FLAGS ctx.SaveMask | |
31 | #define REG_RETVAL ctx.DX[0].U0 | |
32 | #define REG_SYSCALL ctx.DX[0].U1 | |
33 | #define REG_SP ctx.AX[0].U0 | |
34 | #define REG_ARG1 ctx.DX[3].U1 | |
35 | #define REG_ARG2 ctx.DX[3].U0 | |
36 | #define REG_ARG3 ctx.DX[2].U1 | |
37 | #define REG_PC ctx.CurrPC | |
38 | #define REG_RTP ctx.DX[4].U1 | |
39 | ||
40 | struct rt_sigframe { | |
41 | struct siginfo info; | |
42 | struct ucontext uc; | |
43 | unsigned long retcode[2]; | |
44 | }; | |
45 | ||
46 | static int restore_sigcontext(struct pt_regs *regs, | |
47 | struct sigcontext __user *sc) | |
48 | { | |
49 | int err; | |
50 | ||
51 | /* Always make any pending restarted system calls return -EINTR */ | |
f56141e3 | 52 | current->restart_block.fn = do_no_restart_syscall; |
262d96b0 JH |
53 | |
54 | err = metag_gp_regs_copyin(regs, 0, sizeof(struct user_gp_regs), NULL, | |
55 | &sc->regs); | |
56 | if (!err) | |
57 | err = metag_cb_regs_copyin(regs, 0, | |
58 | sizeof(struct user_cb_regs), NULL, | |
59 | &sc->cb); | |
60 | if (!err) | |
61 | err = metag_rp_state_copyin(regs, 0, | |
62 | sizeof(struct user_rp_state), NULL, | |
63 | &sc->rp); | |
64 | ||
65 | /* This is a user-mode context. */ | |
66 | regs->REG_FLAGS |= TBICTX_PRIV_BIT; | |
67 | ||
68 | return err; | |
69 | } | |
70 | ||
71 | long sys_rt_sigreturn(void) | |
72 | { | |
73 | /* NOTE - Meta stack goes UPWARDS - so we wind the stack back */ | |
74 | struct pt_regs *regs = current_pt_regs(); | |
75 | struct rt_sigframe __user *frame; | |
76 | sigset_t set; | |
77 | ||
78 | frame = (__force struct rt_sigframe __user *)(regs->REG_SP - | |
79 | sizeof(*frame)); | |
80 | ||
81 | if (!access_ok(VERIFY_READ, frame, sizeof(*frame))) | |
82 | goto badframe; | |
83 | ||
84 | if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set))) | |
85 | goto badframe; | |
86 | ||
87 | set_current_blocked(&set); | |
88 | ||
89 | if (restore_sigcontext(regs, &frame->uc.uc_mcontext)) | |
90 | goto badframe; | |
91 | ||
92 | if (restore_altstack(&frame->uc.uc_stack)) | |
93 | goto badframe; | |
94 | ||
95 | return regs->REG_RETVAL; | |
96 | ||
97 | badframe: | |
98 | force_sig(SIGSEGV, current); | |
99 | ||
100 | return 0; | |
101 | } | |
102 | ||
103 | static int setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs, | |
104 | unsigned long mask) | |
105 | { | |
106 | int err; | |
107 | ||
108 | err = metag_gp_regs_copyout(regs, 0, sizeof(struct user_gp_regs), NULL, | |
109 | &sc->regs); | |
110 | ||
111 | if (!err) | |
112 | err = metag_cb_regs_copyout(regs, 0, | |
113 | sizeof(struct user_cb_regs), NULL, | |
114 | &sc->cb); | |
115 | if (!err) | |
116 | err = metag_rp_state_copyout(regs, 0, | |
117 | sizeof(struct user_rp_state), NULL, | |
118 | &sc->rp); | |
119 | ||
120 | /* OK, clear that cbuf flag in the old context, or our stored | |
121 | * catch buffer will be restored when we go to call the signal | |
122 | * handler. Also clear out the CBRP RA/RD pipe bit incase | |
123 | * that is pending as well! | |
124 | * Note that as we have already stored this context, these | |
125 | * flags will get restored on sigreturn to their original | |
126 | * state. | |
127 | */ | |
128 | regs->REG_FLAGS &= ~(TBICTX_XCBF_BIT | TBICTX_CBUF_BIT | | |
129 | TBICTX_CBRP_BIT); | |
130 | ||
131 | /* Clear out the LSM_STEP bits in case we are in the middle of | |
132 | * and MSET/MGET. | |
133 | */ | |
134 | regs->ctx.Flags &= ~TXSTATUS_LSM_STEP_BITS; | |
135 | ||
136 | err |= __put_user(mask, &sc->oldmask); | |
137 | ||
138 | return err; | |
139 | } | |
140 | ||
141 | /* | |
142 | * Determine which stack to use.. | |
143 | */ | |
d83961b7 | 144 | static void __user *get_sigframe(struct ksignal *ksig, unsigned long sp) |
262d96b0 | 145 | { |
d83961b7 | 146 | sp = sigsp(sp, ksig); |
262d96b0 JH |
147 | sp = (sp + 7) & ~7; /* 8byte align stack */ |
148 | ||
149 | return (void __user *)sp; | |
150 | } | |
151 | ||
d3c7e511 RW |
152 | static int setup_rt_frame(struct ksignal *ksig, sigset_t *set, |
153 | struct pt_regs *regs) | |
262d96b0 JH |
154 | { |
155 | struct rt_sigframe __user *frame; | |
d3c7e511 | 156 | int err; |
262d96b0 JH |
157 | unsigned long code; |
158 | ||
d83961b7 | 159 | frame = get_sigframe(ksig, regs->REG_SP); |
262d96b0 | 160 | if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) |
d3c7e511 | 161 | return -EFAULT; |
262d96b0 | 162 | |
d3c7e511 | 163 | err = copy_siginfo_to_user(&frame->info, &ksig->info); |
262d96b0 JH |
164 | |
165 | /* Create the ucontext. */ | |
166 | err |= __put_user(0, &frame->uc.uc_flags); | |
167 | err |= __put_user(0, (unsigned long __user *)&frame->uc.uc_link); | |
168 | err |= __save_altstack(&frame->uc.uc_stack, regs->REG_SP); | |
169 | err |= setup_sigcontext(&frame->uc.uc_mcontext, | |
170 | regs, set->sig[0]); | |
171 | err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set)); | |
172 | ||
173 | if (err) | |
d3c7e511 | 174 | return -EFAULT; |
262d96b0 JH |
175 | |
176 | /* Set up to return from userspace. */ | |
177 | ||
178 | /* MOV D1Re0 (D1.0), #__NR_rt_sigreturn */ | |
179 | code = 0x03000004 | (__NR_rt_sigreturn << 3); | |
180 | err |= __put_user(code, (unsigned long __user *)(&frame->retcode[0])); | |
181 | ||
182 | /* SWITCH #__METAG_SW_SYS */ | |
183 | code = __METAG_SW_ENCODING(SYS); | |
184 | err |= __put_user(code, (unsigned long __user *)(&frame->retcode[1])); | |
185 | ||
186 | if (err) | |
d3c7e511 | 187 | return -EFAULT; |
262d96b0 JH |
188 | |
189 | /* Set up registers for signal handler */ | |
190 | regs->REG_RTP = (unsigned long) frame->retcode; | |
191 | regs->REG_SP = (unsigned long) frame + sizeof(*frame); | |
d3c7e511 | 192 | regs->REG_ARG1 = ksig->sig; |
262d96b0 JH |
193 | regs->REG_ARG2 = (unsigned long) &frame->info; |
194 | regs->REG_ARG3 = (unsigned long) &frame->uc; | |
d3c7e511 | 195 | regs->REG_PC = (unsigned long) ksig->ka.sa.sa_handler; |
262d96b0 JH |
196 | |
197 | pr_debug("SIG deliver (%s:%d): sp=%p pc=%08x pr=%08x\n", | |
198 | current->comm, current->pid, frame, regs->REG_PC, | |
199 | regs->REG_RTP); | |
200 | ||
201 | /* Now pass size of 'new code' into sigtramp so we can do a more | |
202 | * effective cache flush - directed rather than 'full flush'. | |
203 | */ | |
204 | flush_cache_sigtramp(regs->REG_RTP, sizeof(frame->retcode)); | |
d3c7e511 | 205 | |
262d96b0 JH |
206 | return 0; |
207 | } | |
208 | ||
d3c7e511 | 209 | static void handle_signal(struct ksignal *ksig, struct pt_regs *regs) |
262d96b0 JH |
210 | { |
211 | sigset_t *oldset = sigmask_to_save(); | |
d3c7e511 | 212 | int ret; |
262d96b0 JH |
213 | |
214 | /* Set up the stack frame */ | |
d3c7e511 | 215 | ret = setup_rt_frame(ksig, oldset, regs); |
262d96b0 | 216 | |
d3c7e511 | 217 | signal_setup_done(ret, ksig, test_thread_flag(TIF_SINGLESTEP)); |
262d96b0 JH |
218 | } |
219 | ||
220 | /* | |
221 | * Notes for Meta. | |
222 | * We have moved from the old 2.4.9 SH way of using syscall_nr (in the stored | |
223 | * context) to passing in the syscall flag on the stack. | |
224 | * This is because having syscall_nr in our context does not fit with TBX, and | |
225 | * corrupted the stack. | |
226 | */ | |
227 | static int do_signal(struct pt_regs *regs, int syscall) | |
228 | { | |
229 | unsigned int retval = 0, continue_addr = 0, restart_addr = 0; | |
262d96b0 | 230 | int restart = 0; |
d3c7e511 | 231 | struct ksignal ksig; |
262d96b0 JH |
232 | |
233 | /* | |
234 | * By the end of rt_sigreturn the context describes the point that the | |
235 | * signal was taken (which may happen to be just before a syscall if | |
236 | * it's already been restarted). This should *never* be mistaken for a | |
237 | * system call in need of restarting. | |
238 | */ | |
239 | if (syscall == __NR_rt_sigreturn) | |
240 | syscall = -1; | |
241 | ||
242 | /* Did we come from a system call? */ | |
243 | if (syscall >= 0) { | |
244 | continue_addr = regs->REG_PC; | |
245 | restart_addr = continue_addr - 4; | |
246 | retval = regs->REG_RETVAL; | |
247 | ||
248 | /* | |
249 | * Prepare for system call restart. We do this here so that a | |
250 | * debugger will see the already changed PC. | |
251 | */ | |
252 | switch (retval) { | |
253 | case -ERESTART_RESTARTBLOCK: | |
254 | restart = -2; | |
255 | case -ERESTARTNOHAND: | |
256 | case -ERESTARTSYS: | |
257 | case -ERESTARTNOINTR: | |
258 | ++restart; | |
259 | regs->REG_PC = restart_addr; | |
260 | break; | |
261 | } | |
262 | } | |
263 | ||
264 | /* | |
265 | * Get the signal to deliver. When running under ptrace, at this point | |
266 | * the debugger may change all our registers ... | |
267 | */ | |
d3c7e511 RW |
268 | get_signal(&ksig); |
269 | ||
262d96b0 JH |
270 | /* |
271 | * Depending on the signal settings we may need to revert the decision | |
272 | * to restart the system call. But skip this if a debugger has chosen to | |
273 | * restart at a different PC. | |
274 | */ | |
275 | if (regs->REG_PC != restart_addr) | |
276 | restart = 0; | |
d3c7e511 | 277 | if (ksig.sig > 0) { |
262d96b0 JH |
278 | if (unlikely(restart)) { |
279 | if (retval == -ERESTARTNOHAND | |
280 | || retval == -ERESTART_RESTARTBLOCK | |
281 | || (retval == -ERESTARTSYS | |
d3c7e511 | 282 | && !(ksig.ka.sa.sa_flags & SA_RESTART))) { |
262d96b0 JH |
283 | regs->REG_RETVAL = -EINTR; |
284 | regs->REG_PC = continue_addr; | |
285 | } | |
286 | } | |
287 | ||
288 | /* Whee! Actually deliver the signal. */ | |
d3c7e511 | 289 | handle_signal(&ksig, regs); |
262d96b0 JH |
290 | return 0; |
291 | } | |
292 | ||
293 | /* Handlerless -ERESTART_RESTARTBLOCK re-enters via restart_syscall */ | |
294 | if (unlikely(restart < 0)) | |
295 | regs->REG_SYSCALL = __NR_restart_syscall; | |
296 | ||
297 | /* | |
298 | * If there's no signal to deliver, we just put the saved sigmask back. | |
299 | */ | |
300 | restore_saved_sigmask(); | |
301 | ||
302 | return restart; | |
303 | } | |
304 | ||
305 | int do_work_pending(struct pt_regs *regs, unsigned int thread_flags, | |
306 | int syscall) | |
307 | { | |
308 | do { | |
309 | if (likely(thread_flags & _TIF_NEED_RESCHED)) { | |
310 | schedule(); | |
311 | } else { | |
312 | if (unlikely(!user_mode(regs))) | |
313 | return 0; | |
314 | local_irq_enable(); | |
315 | if (thread_flags & _TIF_SIGPENDING) { | |
316 | int restart = do_signal(regs, syscall); | |
317 | if (unlikely(restart)) { | |
318 | /* | |
319 | * Restart without handlers. | |
320 | * Deal with it without leaving | |
321 | * the kernel space. | |
322 | */ | |
323 | return restart; | |
324 | } | |
325 | syscall = -1; | |
326 | } else { | |
327 | clear_thread_flag(TIF_NOTIFY_RESUME); | |
328 | tracehook_notify_resume(regs); | |
329 | } | |
330 | } | |
331 | local_irq_disable(); | |
332 | thread_flags = current_thread_info()->flags; | |
333 | } while (thread_flags & _TIF_WORK_MASK); | |
334 | return 0; | |
335 | } |