Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * linux/arch/parisc/kernel/signal.c: Architecture-specific signal | |
3 | * handling support. | |
4 | * | |
5 | * Copyright (C) 2000 David Huggins-Daines <dhd@debian.org> | |
6 | * Copyright (C) 2000 Linuxcare, Inc. | |
7 | * | |
8 | * Based on the ia64, i386, and alpha versions. | |
9 | * | |
10 | * Like the IA-64, we are a recent enough port (we are *starting* | |
11 | * with glibc2.2) that we do not need to support the old non-realtime | |
12 | * Linux signals. Therefore we don't. HP/UX signals will go in | |
13 | * arch/parisc/hpux/signal.c when we figure out how to do them. | |
14 | */ | |
15 | ||
16 | #include <linux/sched.h> | |
17 | #include <linux/mm.h> | |
18 | #include <linux/smp.h> | |
1da177e4 LT |
19 | #include <linux/kernel.h> |
20 | #include <linux/signal.h> | |
21 | #include <linux/errno.h> | |
22 | #include <linux/wait.h> | |
23 | #include <linux/ptrace.h> | |
24 | #include <linux/unistd.h> | |
25 | #include <linux/stddef.h> | |
26 | #include <linux/compat.h> | |
27 | #include <linux/elf.h> | |
1da177e4 LT |
28 | #include <asm/ucontext.h> |
29 | #include <asm/rt_sigframe.h> | |
30 | #include <asm/uaccess.h> | |
31 | #include <asm/pgalloc.h> | |
32 | #include <asm/cacheflush.h> | |
0013a854 | 33 | #include <asm/asm-offsets.h> |
1da177e4 LT |
34 | |
35 | #ifdef CONFIG_COMPAT | |
36 | #include <linux/compat.h> | |
37 | #include "signal32.h" | |
38 | #endif | |
39 | ||
40 | #define DEBUG_SIG 0 | |
41 | #define DEBUG_SIG_LEVEL 2 | |
42 | ||
43 | #if DEBUG_SIG | |
44 | #define DBG(LEVEL, ...) \ | |
45 | ((DEBUG_SIG_LEVEL >= LEVEL) \ | |
46 | ? printk(__VA_ARGS__) : (void) 0) | |
47 | #else | |
48 | #define DBG(LEVEL, ...) | |
49 | #endif | |
50 | ||
51 | ||
52 | #define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP))) | |
53 | ||
54 | /* gcc will complain if a pointer is cast to an integer of different | |
55 | * size. If you really need to do this (and we do for an ELF32 user | |
56 | * application in an ELF64 kernel) then you have to do a cast to an | |
57 | * integer of the same size first. The A() macro accomplishes | |
58 | * this. */ | |
59 | #define A(__x) ((unsigned long)(__x)) | |
60 | ||
1da177e4 LT |
61 | /* |
62 | * Atomically swap in the new signal mask, and wait for a signal. | |
63 | */ | |
a8f44e38 | 64 | #ifdef CONFIG_64BIT |
1da177e4 LT |
65 | #include "sys32.h" |
66 | #endif | |
67 | ||
1da177e4 LT |
68 | /* |
69 | * Do a signal return - restore sigcontext. | |
70 | */ | |
71 | ||
72 | /* Trampoline for calling rt_sigreturn() */ | |
73 | #define INSN_LDI_R25_0 0x34190000 /* ldi 0,%r25 (in_syscall=0) */ | |
74 | #define INSN_LDI_R25_1 0x34190002 /* ldi 1,%r25 (in_syscall=1) */ | |
75 | #define INSN_LDI_R20 0x3414015a /* ldi __NR_rt_sigreturn,%r20 */ | |
76 | #define INSN_BLE_SR2_R0 0xe4008200 /* be,l 0x100(%sr2,%r0),%sr0,%r31 */ | |
77 | #define INSN_NOP 0x08000240 /* nop */ | |
78 | /* For debugging */ | |
79 | #define INSN_DIE_HORRIBLY 0x68000ccc /* stw %r0,0x666(%sr0,%r0) */ | |
80 | ||
81 | static long | |
82 | restore_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs) | |
83 | { | |
84 | long err = 0; | |
85 | ||
86 | err |= __copy_from_user(regs->gr, sc->sc_gr, sizeof(regs->gr)); | |
87 | err |= __copy_from_user(regs->fr, sc->sc_fr, sizeof(regs->fr)); | |
88 | err |= __copy_from_user(regs->iaoq, sc->sc_iaoq, sizeof(regs->iaoq)); | |
89 | err |= __copy_from_user(regs->iasq, sc->sc_iasq, sizeof(regs->iasq)); | |
90 | err |= __get_user(regs->sar, &sc->sc_sar); | |
91 | DBG(2,"restore_sigcontext: iaoq is 0x%#lx / 0x%#lx\n", | |
92 | regs->iaoq[0],regs->iaoq[1]); | |
93 | DBG(2,"restore_sigcontext: r28 is %ld\n", regs->gr[28]); | |
94 | return err; | |
95 | } | |
96 | ||
97 | void | |
98 | sys_rt_sigreturn(struct pt_regs *regs, int in_syscall) | |
99 | { | |
100 | struct rt_sigframe __user *frame; | |
101 | struct siginfo si; | |
102 | sigset_t set; | |
103 | unsigned long usp = (regs->gr[30] & ~(0x01UL)); | |
104 | unsigned long sigframe_size = PARISC_RT_SIGFRAME_SIZE; | |
a8f44e38 | 105 | #ifdef CONFIG_64BIT |
1da177e4 LT |
106 | compat_sigset_t compat_set; |
107 | struct compat_rt_sigframe __user * compat_frame; | |
108 | ||
a3ea84fa | 109 | if (is_compat_task()) |
1da177e4 LT |
110 | sigframe_size = PARISC_RT_SIGFRAME_SIZE32; |
111 | #endif | |
112 | ||
113 | ||
114 | /* Unwind the user stack to get the rt_sigframe structure. */ | |
115 | frame = (struct rt_sigframe __user *) | |
116 | (usp - sigframe_size); | |
117 | DBG(2,"sys_rt_sigreturn: frame is %p\n", frame); | |
118 | ||
a8f44e38 | 119 | #ifdef CONFIG_64BIT |
1da177e4 LT |
120 | compat_frame = (struct compat_rt_sigframe __user *)frame; |
121 | ||
a3ea84fa | 122 | if (is_compat_task()) { |
1da177e4 LT |
123 | DBG(2,"sys_rt_sigreturn: ELF32 process.\n"); |
124 | if (__copy_from_user(&compat_set, &compat_frame->uc.uc_sigmask, sizeof(compat_set))) | |
125 | goto give_sigsegv; | |
126 | sigset_32to64(&set,&compat_set); | |
127 | } else | |
128 | #endif | |
129 | { | |
130 | if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set))) | |
131 | goto give_sigsegv; | |
132 | } | |
133 | ||
134 | sigdelsetmask(&set, ~_BLOCKABLE); | |
135 | spin_lock_irq(¤t->sighand->siglock); | |
136 | current->blocked = set; | |
137 | recalc_sigpending(); | |
138 | spin_unlock_irq(¤t->sighand->siglock); | |
139 | ||
140 | /* Good thing we saved the old gr[30], eh? */ | |
a8f44e38 | 141 | #ifdef CONFIG_64BIT |
a3ea84fa | 142 | if (is_compat_task()) { |
1da177e4 LT |
143 | DBG(1,"sys_rt_sigreturn: compat_frame->uc.uc_mcontext 0x%p\n", |
144 | &compat_frame->uc.uc_mcontext); | |
145 | // FIXME: Load upper half from register file | |
146 | if (restore_sigcontext32(&compat_frame->uc.uc_mcontext, | |
147 | &compat_frame->regs, regs)) | |
148 | goto give_sigsegv; | |
149 | DBG(1,"sys_rt_sigreturn: usp %#08lx stack 0x%p\n", | |
150 | usp, &compat_frame->uc.uc_stack); | |
151 | if (do_sigaltstack32(&compat_frame->uc.uc_stack, NULL, usp) == -EFAULT) | |
152 | goto give_sigsegv; | |
153 | } else | |
154 | #endif | |
155 | { | |
156 | DBG(1,"sys_rt_sigreturn: frame->uc.uc_mcontext 0x%p\n", | |
157 | &frame->uc.uc_mcontext); | |
158 | if (restore_sigcontext(&frame->uc.uc_mcontext, regs)) | |
159 | goto give_sigsegv; | |
160 | DBG(1,"sys_rt_sigreturn: usp %#08lx stack 0x%p\n", | |
161 | usp, &frame->uc.uc_stack); | |
162 | if (do_sigaltstack(&frame->uc.uc_stack, NULL, usp) == -EFAULT) | |
163 | goto give_sigsegv; | |
164 | } | |
165 | ||
166 | ||
167 | ||
168 | /* If we are on the syscall path IAOQ will not be restored, and | |
169 | * if we are on the interrupt path we must not corrupt gr31. | |
170 | */ | |
171 | if (in_syscall) | |
172 | regs->gr[31] = regs->iaoq[0]; | |
173 | #if DEBUG_SIG | |
174 | DBG(1,"sys_rt_sigreturn: returning to %#lx, DUMPING REGS:\n", regs->iaoq[0]); | |
175 | show_regs(regs); | |
176 | #endif | |
177 | return; | |
178 | ||
179 | give_sigsegv: | |
180 | DBG(1,"sys_rt_sigreturn: Sending SIGSEGV\n"); | |
181 | si.si_signo = SIGSEGV; | |
182 | si.si_errno = 0; | |
183 | si.si_code = SI_KERNEL; | |
b488893a | 184 | si.si_pid = task_pid_vnr(current); |
1da177e4 LT |
185 | si.si_uid = current->uid; |
186 | si.si_addr = &frame->uc; | |
187 | force_sig_info(SIGSEGV, &si, current); | |
188 | return; | |
189 | } | |
190 | ||
191 | /* | |
192 | * Set up a signal frame. | |
193 | */ | |
194 | ||
195 | static inline void __user * | |
196 | get_sigframe(struct k_sigaction *ka, unsigned long sp, size_t frame_size) | |
197 | { | |
198 | /*FIXME: ELF32 vs. ELF64 has different frame_size, but since we | |
199 | don't use the parameter it doesn't matter */ | |
200 | ||
201 | DBG(1,"get_sigframe: ka = %#lx, sp = %#lx, frame_size = %#lx\n", | |
202 | (unsigned long)ka, sp, frame_size); | |
203 | ||
d09042da | 204 | if ((ka->sa.sa_flags & SA_ONSTACK) != 0 && ! sas_ss_flags(sp)) |
1da177e4 LT |
205 | sp = current->sas_ss_sp; /* Stacks grow up! */ |
206 | ||
207 | DBG(1,"get_sigframe: Returning sp = %#lx\n", (unsigned long)sp); | |
208 | return (void __user *) sp; /* Stacks grow up. Fun. */ | |
209 | } | |
210 | ||
211 | static long | |
212 | setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs, int in_syscall) | |
213 | ||
214 | { | |
215 | unsigned long flags = 0; | |
216 | long err = 0; | |
217 | ||
218 | if (on_sig_stack((unsigned long) sc)) | |
219 | flags |= PARISC_SC_FLAG_ONSTACK; | |
220 | if (in_syscall) { | |
221 | flags |= PARISC_SC_FLAG_IN_SYSCALL; | |
222 | /* regs->iaoq is undefined in the syscall return path */ | |
223 | err |= __put_user(regs->gr[31], &sc->sc_iaoq[0]); | |
224 | err |= __put_user(regs->gr[31]+4, &sc->sc_iaoq[1]); | |
225 | err |= __put_user(regs->sr[3], &sc->sc_iasq[0]); | |
226 | err |= __put_user(regs->sr[3], &sc->sc_iasq[1]); | |
227 | DBG(1,"setup_sigcontext: iaoq %#lx / %#lx (in syscall)\n", | |
228 | regs->gr[31], regs->gr[31]+4); | |
229 | } else { | |
230 | err |= __copy_to_user(sc->sc_iaoq, regs->iaoq, sizeof(regs->iaoq)); | |
231 | err |= __copy_to_user(sc->sc_iasq, regs->iasq, sizeof(regs->iasq)); | |
232 | DBG(1,"setup_sigcontext: iaoq %#lx / %#lx (not in syscall)\n", | |
233 | regs->iaoq[0], regs->iaoq[1]); | |
234 | } | |
235 | ||
236 | err |= __put_user(flags, &sc->sc_flags); | |
237 | err |= __copy_to_user(sc->sc_gr, regs->gr, sizeof(regs->gr)); | |
238 | err |= __copy_to_user(sc->sc_fr, regs->fr, sizeof(regs->fr)); | |
239 | err |= __put_user(regs->sar, &sc->sc_sar); | |
240 | DBG(1,"setup_sigcontext: r28 is %ld\n", regs->gr[28]); | |
241 | ||
242 | return err; | |
243 | } | |
244 | ||
245 | static long | |
246 | setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info, | |
247 | sigset_t *set, struct pt_regs *regs, int in_syscall) | |
248 | { | |
249 | struct rt_sigframe __user *frame; | |
250 | unsigned long rp, usp; | |
251 | unsigned long haddr, sigframe_size; | |
1da177e4 | 252 | int err = 0; |
a8f44e38 | 253 | #ifdef CONFIG_64BIT |
1da177e4 LT |
254 | compat_int_t compat_val; |
255 | struct compat_rt_sigframe __user * compat_frame; | |
256 | compat_sigset_t compat_set; | |
257 | #endif | |
258 | ||
259 | usp = (regs->gr[30] & ~(0x01UL)); | |
260 | /*FIXME: frame_size parameter is unused, remove it. */ | |
261 | frame = get_sigframe(ka, usp, sizeof(*frame)); | |
262 | ||
263 | DBG(1,"SETUP_RT_FRAME: START\n"); | |
264 | DBG(1,"setup_rt_frame: frame %p info %p\n", frame, info); | |
265 | ||
266 | ||
a8f44e38 | 267 | #ifdef CONFIG_64BIT |
1da177e4 LT |
268 | |
269 | compat_frame = (struct compat_rt_sigframe __user *)frame; | |
270 | ||
a3ea84fa | 271 | if (is_compat_task()) { |
1da177e4 | 272 | DBG(1,"setup_rt_frame: frame->info = 0x%p\n", &compat_frame->info); |
f671c45d | 273 | err |= copy_siginfo_to_user32(&compat_frame->info, info); |
1da177e4 LT |
274 | DBG(1,"SETUP_RT_FRAME: 1\n"); |
275 | compat_val = (compat_int_t)current->sas_ss_sp; | |
276 | err |= __put_user(compat_val, &compat_frame->uc.uc_stack.ss_sp); | |
277 | DBG(1,"SETUP_RT_FRAME: 2\n"); | |
278 | compat_val = (compat_int_t)current->sas_ss_size; | |
279 | err |= __put_user(compat_val, &compat_frame->uc.uc_stack.ss_size); | |
280 | DBG(1,"SETUP_RT_FRAME: 3\n"); | |
281 | compat_val = sas_ss_flags(regs->gr[30]); | |
282 | err |= __put_user(compat_val, &compat_frame->uc.uc_stack.ss_flags); | |
283 | DBG(1,"setup_rt_frame: frame->uc = 0x%p\n", &compat_frame->uc); | |
284 | DBG(1,"setup_rt_frame: frame->uc.uc_mcontext = 0x%p\n", &compat_frame->uc.uc_mcontext); | |
285 | err |= setup_sigcontext32(&compat_frame->uc.uc_mcontext, | |
286 | &compat_frame->regs, regs, in_syscall); | |
287 | sigset_64to32(&compat_set,set); | |
288 | err |= __copy_to_user(&compat_frame->uc.uc_sigmask, &compat_set, sizeof(compat_set)); | |
289 | } else | |
290 | #endif | |
291 | { | |
292 | DBG(1,"setup_rt_frame: frame->info = 0x%p\n", &frame->info); | |
293 | err |= copy_siginfo_to_user(&frame->info, info); | |
294 | err |= __put_user(current->sas_ss_sp, &frame->uc.uc_stack.ss_sp); | |
295 | err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size); | |
296 | err |= __put_user(sas_ss_flags(regs->gr[30]), | |
297 | &frame->uc.uc_stack.ss_flags); | |
298 | DBG(1,"setup_rt_frame: frame->uc = 0x%p\n", &frame->uc); | |
299 | DBG(1,"setup_rt_frame: frame->uc.uc_mcontext = 0x%p\n", &frame->uc.uc_mcontext); | |
300 | err |= setup_sigcontext(&frame->uc.uc_mcontext, regs, in_syscall); | |
301 | /* FIXME: Should probably be converted aswell for the compat case */ | |
302 | err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set)); | |
303 | } | |
304 | ||
305 | if (err) | |
306 | goto give_sigsegv; | |
307 | ||
308 | /* Set up to return from userspace. If provided, use a stub | |
309 | already in userspace. The first words of tramp are used to | |
310 | save the previous sigrestartblock trampoline that might be | |
311 | on the stack. We start the sigreturn trampoline at | |
312 | SIGRESTARTBLOCK_TRAMP+X. */ | |
313 | err |= __put_user(in_syscall ? INSN_LDI_R25_1 : INSN_LDI_R25_0, | |
314 | &frame->tramp[SIGRESTARTBLOCK_TRAMP+0]); | |
315 | err |= __put_user(INSN_LDI_R20, | |
316 | &frame->tramp[SIGRESTARTBLOCK_TRAMP+1]); | |
317 | err |= __put_user(INSN_BLE_SR2_R0, | |
318 | &frame->tramp[SIGRESTARTBLOCK_TRAMP+2]); | |
319 | err |= __put_user(INSN_NOP, &frame->tramp[SIGRESTARTBLOCK_TRAMP+3]); | |
320 | ||
321 | #if DEBUG_SIG | |
322 | /* Assert that we're flushing in the correct space... */ | |
323 | { | |
324 | int sid; | |
325 | asm ("mfsp %%sr3,%0" : "=r" (sid)); | |
326 | DBG(1,"setup_rt_frame: Flushing 64 bytes at space %#x offset %p\n", | |
327 | sid, frame->tramp); | |
328 | } | |
329 | #endif | |
330 | ||
331 | flush_user_dcache_range((unsigned long) &frame->tramp[0], | |
332 | (unsigned long) &frame->tramp[TRAMP_SIZE]); | |
333 | flush_user_icache_range((unsigned long) &frame->tramp[0], | |
334 | (unsigned long) &frame->tramp[TRAMP_SIZE]); | |
335 | ||
efad798b | 336 | /* TRAMP Words 0-4, Length 5 = SIGRESTARTBLOCK_TRAMP |
1da177e4 LT |
337 | * TRAMP Words 5-9, Length 4 = SIGRETURN_TRAMP |
338 | * So the SIGRETURN_TRAMP is at the end of SIGRESTARTBLOCK_TRAMP | |
339 | */ | |
340 | rp = (unsigned long) &frame->tramp[SIGRESTARTBLOCK_TRAMP]; | |
341 | ||
342 | if (err) | |
343 | goto give_sigsegv; | |
344 | ||
345 | haddr = A(ka->sa.sa_handler); | |
346 | /* The sa_handler may be a pointer to a function descriptor */ | |
a8f44e38 | 347 | #ifdef CONFIG_64BIT |
a3ea84fa | 348 | if (is_compat_task()) { |
1da177e4 LT |
349 | #endif |
350 | if (haddr & PA_PLABEL_FDESC) { | |
351 | Elf32_Fdesc fdesc; | |
352 | Elf32_Fdesc __user *ufdesc = (Elf32_Fdesc __user *)A(haddr & ~3); | |
353 | ||
354 | err = __copy_from_user(&fdesc, ufdesc, sizeof(fdesc)); | |
355 | ||
356 | if (err) | |
357 | goto give_sigsegv; | |
358 | ||
359 | haddr = fdesc.addr; | |
360 | regs->gr[19] = fdesc.gp; | |
361 | } | |
a8f44e38 | 362 | #ifdef CONFIG_64BIT |
1da177e4 LT |
363 | } else { |
364 | Elf64_Fdesc fdesc; | |
365 | Elf64_Fdesc __user *ufdesc = (Elf64_Fdesc __user *)A(haddr & ~3); | |
366 | ||
367 | err = __copy_from_user(&fdesc, ufdesc, sizeof(fdesc)); | |
368 | ||
369 | if (err) | |
370 | goto give_sigsegv; | |
371 | ||
372 | haddr = fdesc.addr; | |
373 | regs->gr[19] = fdesc.gp; | |
374 | DBG(1,"setup_rt_frame: 64 bit signal, exe=%#lx, r19=%#lx, in_syscall=%d\n", | |
375 | haddr, regs->gr[19], in_syscall); | |
376 | } | |
377 | #endif | |
378 | ||
379 | /* The syscall return path will create IAOQ values from r31. | |
380 | */ | |
381 | sigframe_size = PARISC_RT_SIGFRAME_SIZE; | |
a8f44e38 | 382 | #ifdef CONFIG_64BIT |
a3ea84fa | 383 | if (is_compat_task()) |
1da177e4 LT |
384 | sigframe_size = PARISC_RT_SIGFRAME_SIZE32; |
385 | #endif | |
386 | if (in_syscall) { | |
387 | regs->gr[31] = haddr; | |
a8f44e38 | 388 | #ifdef CONFIG_64BIT |
df570b9c | 389 | if (!test_thread_flag(TIF_32BIT)) |
1da177e4 LT |
390 | sigframe_size |= 1; |
391 | #endif | |
392 | } else { | |
393 | unsigned long psw = USER_PSW; | |
a8f44e38 | 394 | #ifdef CONFIG_64BIT |
df570b9c | 395 | if (!test_thread_flag(TIF_32BIT)) |
1da177e4 LT |
396 | psw |= PSW_W; |
397 | #endif | |
398 | ||
399 | /* If we are singlestepping, arrange a trap to be delivered | |
400 | when we return to userspace. Note the semantics -- we | |
401 | should trap before the first insn in the handler is | |
402 | executed. Ref: | |
403 | http://sources.redhat.com/ml/gdb/2004-11/msg00245.html | |
404 | */ | |
405 | if (pa_psw(current)->r) { | |
406 | pa_psw(current)->r = 0; | |
407 | psw |= PSW_R; | |
408 | mtctl(-1, 0); | |
409 | } | |
410 | ||
411 | regs->gr[0] = psw; | |
412 | regs->iaoq[0] = haddr | 3; | |
413 | regs->iaoq[1] = regs->iaoq[0] + 4; | |
414 | } | |
415 | ||
416 | regs->gr[2] = rp; /* userland return pointer */ | |
417 | regs->gr[26] = sig; /* signal number */ | |
418 | ||
a8f44e38 | 419 | #ifdef CONFIG_64BIT |
a3ea84fa | 420 | if (is_compat_task()) { |
1da177e4 LT |
421 | regs->gr[25] = A(&compat_frame->info); /* siginfo pointer */ |
422 | regs->gr[24] = A(&compat_frame->uc); /* ucontext pointer */ | |
423 | } else | |
424 | #endif | |
425 | { | |
426 | regs->gr[25] = A(&frame->info); /* siginfo pointer */ | |
427 | regs->gr[24] = A(&frame->uc); /* ucontext pointer */ | |
428 | } | |
429 | ||
430 | DBG(1,"setup_rt_frame: making sigreturn frame: %#lx + %#lx = %#lx\n", | |
431 | regs->gr[30], sigframe_size, | |
432 | regs->gr[30] + sigframe_size); | |
433 | /* Raise the user stack pointer to make a proper call frame. */ | |
434 | regs->gr[30] = (A(frame) + sigframe_size); | |
435 | ||
436 | ||
437 | DBG(1,"setup_rt_frame: sig deliver (%s,%d) frame=0x%p sp=%#lx iaoq=%#lx/%#lx rp=%#lx\n", | |
438 | current->comm, current->pid, frame, regs->gr[30], | |
439 | regs->iaoq[0], regs->iaoq[1], rp); | |
440 | ||
441 | return 1; | |
442 | ||
443 | give_sigsegv: | |
444 | DBG(1,"setup_rt_frame: sending SIGSEGV\n"); | |
40c72f20 | 445 | force_sigsegv(sig, current); |
1da177e4 LT |
446 | return 0; |
447 | } | |
448 | ||
449 | /* | |
450 | * OK, we're invoking a handler. | |
451 | */ | |
452 | ||
453 | static long | |
454 | handle_signal(unsigned long sig, siginfo_t *info, struct k_sigaction *ka, | |
455 | sigset_t *oldset, struct pt_regs *regs, int in_syscall) | |
456 | { | |
457 | DBG(1,"handle_signal: sig=%ld, ka=%p, info=%p, oldset=%p, regs=%p\n", | |
458 | sig, ka, info, oldset, regs); | |
459 | ||
460 | /* Set up the stack frame */ | |
461 | if (!setup_rt_frame(sig, ka, info, oldset, regs, in_syscall)) | |
462 | return 0; | |
463 | ||
69be8f18 SR |
464 | spin_lock_irq(¤t->sighand->siglock); |
465 | sigorsets(¤t->blocked,¤t->blocked,&ka->sa.sa_mask); | |
466 | if (!(ka->sa.sa_flags & SA_NODEFER)) | |
1da177e4 | 467 | sigaddset(¤t->blocked,sig); |
69be8f18 SR |
468 | recalc_sigpending(); |
469 | spin_unlock_irq(¤t->sighand->siglock); | |
1da177e4 LT |
470 | return 1; |
471 | } | |
472 | ||
2b163b71 KM |
473 | static inline void |
474 | syscall_restart(struct pt_regs *regs, struct k_sigaction *ka) | |
475 | { | |
476 | /* Check the return code */ | |
477 | switch (regs->gr[28]) { | |
478 | case -ERESTART_RESTARTBLOCK: | |
479 | current_thread_info()->restart_block.fn = | |
480 | do_no_restart_syscall; | |
481 | case -ERESTARTNOHAND: | |
482 | DBG(1,"ERESTARTNOHAND: returning -EINTR\n"); | |
483 | regs->gr[28] = -EINTR; | |
484 | break; | |
485 | ||
486 | case -ERESTARTSYS: | |
487 | if (!(ka->sa.sa_flags & SA_RESTART)) { | |
488 | DBG(1,"ERESTARTSYS: putting -EINTR\n"); | |
489 | regs->gr[28] = -EINTR; | |
490 | break; | |
491 | } | |
492 | /* fallthrough */ | |
493 | case -ERESTARTNOINTR: | |
494 | /* A syscall is just a branch, so all | |
495 | * we have to do is fiddle the return pointer. | |
496 | */ | |
497 | regs->gr[31] -= 8; /* delayed branching */ | |
498 | /* Preserve original r28. */ | |
499 | regs->gr[28] = regs->orig_r28; | |
500 | break; | |
501 | } | |
502 | } | |
503 | ||
504 | static inline void | |
505 | insert_restart_trampoline(struct pt_regs *regs) | |
506 | { | |
507 | switch(regs->gr[28]) { | |
508 | case -ERESTART_RESTARTBLOCK: { | |
509 | /* Restart the system call - no handlers present */ | |
510 | unsigned int *usp = (unsigned int *)regs->gr[30]; | |
511 | ||
512 | /* Setup a trampoline to restart the syscall | |
513 | * with __NR_restart_syscall | |
514 | * | |
515 | * 0: <return address (orig r31)> | |
516 | * 4: <2nd half for 64-bit> | |
517 | * 8: ldw 0(%sp), %r31 | |
518 | * 12: be 0x100(%sr2, %r0) | |
519 | * 16: ldi __NR_restart_syscall, %r20 | |
520 | */ | |
521 | #ifdef CONFIG_64BIT | |
522 | put_user(regs->gr[31] >> 32, &usp[0]); | |
523 | put_user(regs->gr[31] & 0xffffffff, &usp[1]); | |
524 | put_user(0x0fc010df, &usp[2]); | |
525 | #else | |
526 | put_user(regs->gr[31], &usp[0]); | |
527 | put_user(0x0fc0109f, &usp[2]); | |
528 | #endif | |
529 | put_user(0xe0008200, &usp[3]); | |
530 | put_user(0x34140000, &usp[4]); | |
531 | ||
532 | /* Stack is 64-byte aligned, and we only need | |
533 | * to flush 1 cache line. | |
534 | * Flushing one cacheline is cheap. | |
535 | * "sync" on bigger (> 4 way) boxes is not. | |
536 | */ | |
cf39cc3b KM |
537 | flush_user_dcache_range(regs->gr[30], regs->gr[30] + 4); |
538 | flush_user_icache_range(regs->gr[30], regs->gr[30] + 4); | |
2b163b71 KM |
539 | |
540 | regs->gr[31] = regs->gr[30] + 8; | |
541 | /* Preserve original r28. */ | |
542 | regs->gr[28] = regs->orig_r28; | |
543 | ||
544 | return; | |
545 | } | |
546 | case -ERESTARTNOHAND: | |
547 | case -ERESTARTSYS: | |
548 | case -ERESTARTNOINTR: { | |
549 | /* Hooray for delayed branching. We don't | |
550 | * have to restore %r20 (the system call | |
551 | * number) because it gets loaded in the delay | |
552 | * slot of the branch external instruction. | |
553 | */ | |
554 | regs->gr[31] -= 8; | |
555 | /* Preserve original r28. */ | |
556 | regs->gr[28] = regs->orig_r28; | |
557 | ||
558 | return; | |
559 | } | |
560 | default: | |
561 | break; | |
562 | } | |
563 | } | |
564 | ||
1da177e4 LT |
565 | /* |
566 | * Note that 'init' is a special process: it doesn't get signals it doesn't | |
567 | * want to handle. Thus you cannot kill init even with a SIGKILL even by | |
568 | * mistake. | |
569 | * | |
570 | * We need to be able to restore the syscall arguments (r21-r26) to | |
571 | * restart syscalls. Thus, the syscall path should save them in the | |
572 | * pt_regs structure (it's okay to do so since they are caller-save | |
573 | * registers). As noted below, the syscall number gets restored for | |
574 | * us due to the magic of delayed branching. | |
575 | */ | |
4650f0a5 KM |
576 | asmlinkage void |
577 | do_signal(struct pt_regs *regs, long in_syscall) | |
1da177e4 LT |
578 | { |
579 | siginfo_t info; | |
580 | struct k_sigaction ka; | |
581 | int signr; | |
4650f0a5 | 582 | sigset_t *oldset; |
1da177e4 LT |
583 | |
584 | DBG(1,"\ndo_signal: oldset=0x%p, regs=0x%p, sr7 %#lx, in_syscall=%d\n", | |
585 | oldset, regs, regs->sr[7], in_syscall); | |
586 | ||
587 | /* Everyone else checks to see if they are in kernel mode at | |
588 | this point and exits if that's the case. I'm not sure why | |
589 | we would be called in that case, but for some reason we | |
590 | are. */ | |
591 | ||
4650f0a5 KM |
592 | if (test_thread_flag(TIF_RESTORE_SIGMASK)) |
593 | oldset = ¤t->saved_sigmask; | |
594 | else | |
1da177e4 LT |
595 | oldset = ¤t->blocked; |
596 | ||
597 | DBG(1,"do_signal: oldset %08lx / %08lx\n", | |
598 | oldset->sig[0], oldset->sig[1]); | |
599 | ||
600 | ||
601 | /* May need to force signal if handle_signal failed to deliver */ | |
602 | while (1) { | |
603 | ||
604 | signr = get_signal_to_deliver(&info, &ka, regs, NULL); | |
605 | DBG(3,"do_signal: signr = %d, regs->gr[28] = %ld\n", signr, regs->gr[28]); | |
606 | ||
607 | if (signr <= 0) | |
608 | break; | |
609 | ||
610 | /* Restart a system call if necessary. */ | |
2b163b71 KM |
611 | if (in_syscall) |
612 | syscall_restart(regs, &ka); | |
613 | ||
1da177e4 LT |
614 | /* Whee! Actually deliver the signal. If the |
615 | delivery failed, we need to continue to iterate in | |
616 | this loop so we can deliver the SIGSEGV... */ | |
2b163b71 KM |
617 | if (handle_signal(signr, &info, &ka, oldset, |
618 | regs, in_syscall)) { | |
1da177e4 LT |
619 | DBG(1,KERN_DEBUG "do_signal: Exit (success), regs->gr[28] = %ld\n", |
620 | regs->gr[28]); | |
4650f0a5 KM |
621 | if (test_thread_flag(TIF_RESTORE_SIGMASK)) |
622 | clear_thread_flag(TIF_RESTORE_SIGMASK); | |
623 | return; | |
1da177e4 LT |
624 | } |
625 | } | |
626 | /* end of while(1) looping forever if we can't force a signal */ | |
627 | ||
628 | /* Did we come from a system call? */ | |
2b163b71 KM |
629 | if (in_syscall) |
630 | insert_restart_trampoline(regs); | |
1da177e4 LT |
631 | |
632 | DBG(1,"do_signal: Exit (not delivered), regs->gr[28] = %ld\n", | |
633 | regs->gr[28]); | |
634 | ||
4650f0a5 KM |
635 | if (test_thread_flag(TIF_RESTORE_SIGMASK)) { |
636 | clear_thread_flag(TIF_RESTORE_SIGMASK); | |
637 | sigprocmask(SIG_SETMASK, ¤t->saved_sigmask, NULL); | |
638 | } | |
639 | ||
640 | return; | |
641 | } | |
642 | ||
643 | void do_notify_resume(struct pt_regs *regs, long in_syscall) | |
644 | { | |
645 | if (test_thread_flag(TIF_SIGPENDING) || | |
646 | test_thread_flag(TIF_RESTORE_SIGMASK)) | |
647 | do_signal(regs, in_syscall); | |
1da177e4 | 648 | } |