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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> | |
733e5e4b | 28 | #include <linux/tracehook.h> |
1da177e4 LT |
29 | #include <asm/ucontext.h> |
30 | #include <asm/rt_sigframe.h> | |
31 | #include <asm/uaccess.h> | |
32 | #include <asm/pgalloc.h> | |
33 | #include <asm/cacheflush.h> | |
0013a854 | 34 | #include <asm/asm-offsets.h> |
1da177e4 LT |
35 | |
36 | #ifdef CONFIG_COMPAT | |
37 | #include <linux/compat.h> | |
38 | #include "signal32.h" | |
39 | #endif | |
40 | ||
41 | #define DEBUG_SIG 0 | |
42 | #define DEBUG_SIG_LEVEL 2 | |
43 | ||
44 | #if DEBUG_SIG | |
45 | #define DBG(LEVEL, ...) \ | |
46 | ((DEBUG_SIG_LEVEL >= LEVEL) \ | |
47 | ? printk(__VA_ARGS__) : (void) 0) | |
48 | #else | |
49 | #define DBG(LEVEL, ...) | |
50 | #endif | |
51 | ||
52 | ||
53 | #define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP))) | |
54 | ||
55 | /* gcc will complain if a pointer is cast to an integer of different | |
56 | * size. If you really need to do this (and we do for an ELF32 user | |
57 | * application in an ELF64 kernel) then you have to do a cast to an | |
58 | * integer of the same size first. The A() macro accomplishes | |
59 | * this. */ | |
60 | #define A(__x) ((unsigned long)(__x)) | |
61 | ||
1da177e4 LT |
62 | /* |
63 | * Atomically swap in the new signal mask, and wait for a signal. | |
64 | */ | |
a8f44e38 | 65 | #ifdef CONFIG_64BIT |
1da177e4 LT |
66 | #include "sys32.h" |
67 | #endif | |
68 | ||
1da177e4 LT |
69 | /* |
70 | * Do a signal return - restore sigcontext. | |
71 | */ | |
72 | ||
73 | /* Trampoline for calling rt_sigreturn() */ | |
74 | #define INSN_LDI_R25_0 0x34190000 /* ldi 0,%r25 (in_syscall=0) */ | |
75 | #define INSN_LDI_R25_1 0x34190002 /* ldi 1,%r25 (in_syscall=1) */ | |
76 | #define INSN_LDI_R20 0x3414015a /* ldi __NR_rt_sigreturn,%r20 */ | |
77 | #define INSN_BLE_SR2_R0 0xe4008200 /* be,l 0x100(%sr2,%r0),%sr0,%r31 */ | |
78 | #define INSN_NOP 0x08000240 /* nop */ | |
79 | /* For debugging */ | |
80 | #define INSN_DIE_HORRIBLY 0x68000ccc /* stw %r0,0x666(%sr0,%r0) */ | |
81 | ||
82 | static long | |
83 | restore_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs) | |
84 | { | |
85 | long err = 0; | |
86 | ||
87 | err |= __copy_from_user(regs->gr, sc->sc_gr, sizeof(regs->gr)); | |
88 | err |= __copy_from_user(regs->fr, sc->sc_fr, sizeof(regs->fr)); | |
89 | err |= __copy_from_user(regs->iaoq, sc->sc_iaoq, sizeof(regs->iaoq)); | |
90 | err |= __copy_from_user(regs->iasq, sc->sc_iasq, sizeof(regs->iasq)); | |
91 | err |= __get_user(regs->sar, &sc->sc_sar); | |
92 | DBG(2,"restore_sigcontext: iaoq is 0x%#lx / 0x%#lx\n", | |
93 | regs->iaoq[0],regs->iaoq[1]); | |
94 | DBG(2,"restore_sigcontext: r28 is %ld\n", regs->gr[28]); | |
95 | return err; | |
96 | } | |
97 | ||
98 | void | |
99 | sys_rt_sigreturn(struct pt_regs *regs, int in_syscall) | |
100 | { | |
101 | struct rt_sigframe __user *frame; | |
102 | struct siginfo si; | |
103 | sigset_t set; | |
104 | unsigned long usp = (regs->gr[30] & ~(0x01UL)); | |
105 | unsigned long sigframe_size = PARISC_RT_SIGFRAME_SIZE; | |
a8f44e38 | 106 | #ifdef CONFIG_64BIT |
1da177e4 LT |
107 | compat_sigset_t compat_set; |
108 | struct compat_rt_sigframe __user * compat_frame; | |
109 | ||
a3ea84fa | 110 | if (is_compat_task()) |
1da177e4 LT |
111 | sigframe_size = PARISC_RT_SIGFRAME_SIZE32; |
112 | #endif | |
113 | ||
114 | ||
115 | /* Unwind the user stack to get the rt_sigframe structure. */ | |
116 | frame = (struct rt_sigframe __user *) | |
117 | (usp - sigframe_size); | |
118 | DBG(2,"sys_rt_sigreturn: frame is %p\n", frame); | |
119 | ||
a8f44e38 | 120 | #ifdef CONFIG_64BIT |
1da177e4 LT |
121 | compat_frame = (struct compat_rt_sigframe __user *)frame; |
122 | ||
a3ea84fa | 123 | if (is_compat_task()) { |
1da177e4 LT |
124 | DBG(2,"sys_rt_sigreturn: ELF32 process.\n"); |
125 | if (__copy_from_user(&compat_set, &compat_frame->uc.uc_sigmask, sizeof(compat_set))) | |
126 | goto give_sigsegv; | |
127 | sigset_32to64(&set,&compat_set); | |
128 | } else | |
129 | #endif | |
130 | { | |
131 | if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set))) | |
132 | goto give_sigsegv; | |
133 | } | |
134 | ||
135 | sigdelsetmask(&set, ~_BLOCKABLE); | |
136 | spin_lock_irq(¤t->sighand->siglock); | |
137 | current->blocked = set; | |
138 | recalc_sigpending(); | |
139 | spin_unlock_irq(¤t->sighand->siglock); | |
140 | ||
141 | /* Good thing we saved the old gr[30], eh? */ | |
a8f44e38 | 142 | #ifdef CONFIG_64BIT |
a3ea84fa | 143 | if (is_compat_task()) { |
1da177e4 LT |
144 | DBG(1,"sys_rt_sigreturn: compat_frame->uc.uc_mcontext 0x%p\n", |
145 | &compat_frame->uc.uc_mcontext); | |
146 | // FIXME: Load upper half from register file | |
147 | if (restore_sigcontext32(&compat_frame->uc.uc_mcontext, | |
148 | &compat_frame->regs, regs)) | |
149 | goto give_sigsegv; | |
150 | DBG(1,"sys_rt_sigreturn: usp %#08lx stack 0x%p\n", | |
151 | usp, &compat_frame->uc.uc_stack); | |
152 | if (do_sigaltstack32(&compat_frame->uc.uc_stack, NULL, usp) == -EFAULT) | |
153 | goto give_sigsegv; | |
154 | } else | |
155 | #endif | |
156 | { | |
157 | DBG(1,"sys_rt_sigreturn: frame->uc.uc_mcontext 0x%p\n", | |
158 | &frame->uc.uc_mcontext); | |
159 | if (restore_sigcontext(&frame->uc.uc_mcontext, regs)) | |
160 | goto give_sigsegv; | |
161 | DBG(1,"sys_rt_sigreturn: usp %#08lx stack 0x%p\n", | |
162 | usp, &frame->uc.uc_stack); | |
163 | if (do_sigaltstack(&frame->uc.uc_stack, NULL, usp) == -EFAULT) | |
164 | goto give_sigsegv; | |
165 | } | |
166 | ||
167 | ||
168 | ||
169 | /* If we are on the syscall path IAOQ will not be restored, and | |
170 | * if we are on the interrupt path we must not corrupt gr31. | |
171 | */ | |
172 | if (in_syscall) | |
173 | regs->gr[31] = regs->iaoq[0]; | |
174 | #if DEBUG_SIG | |
175 | DBG(1,"sys_rt_sigreturn: returning to %#lx, DUMPING REGS:\n", regs->iaoq[0]); | |
176 | show_regs(regs); | |
177 | #endif | |
178 | return; | |
179 | ||
180 | give_sigsegv: | |
181 | DBG(1,"sys_rt_sigreturn: Sending SIGSEGV\n"); | |
182 | si.si_signo = SIGSEGV; | |
183 | si.si_errno = 0; | |
184 | si.si_code = SI_KERNEL; | |
b488893a | 185 | si.si_pid = task_pid_vnr(current); |
25e15731 | 186 | si.si_uid = current_uid(); |
1da177e4 LT |
187 | si.si_addr = &frame->uc; |
188 | force_sig_info(SIGSEGV, &si, current); | |
189 | return; | |
190 | } | |
191 | ||
192 | /* | |
193 | * Set up a signal frame. | |
194 | */ | |
195 | ||
196 | static inline void __user * | |
197 | get_sigframe(struct k_sigaction *ka, unsigned long sp, size_t frame_size) | |
198 | { | |
199 | /*FIXME: ELF32 vs. ELF64 has different frame_size, but since we | |
200 | don't use the parameter it doesn't matter */ | |
201 | ||
202 | DBG(1,"get_sigframe: ka = %#lx, sp = %#lx, frame_size = %#lx\n", | |
203 | (unsigned long)ka, sp, frame_size); | |
204 | ||
d09042da | 205 | if ((ka->sa.sa_flags & SA_ONSTACK) != 0 && ! sas_ss_flags(sp)) |
1da177e4 LT |
206 | sp = current->sas_ss_sp; /* Stacks grow up! */ |
207 | ||
208 | DBG(1,"get_sigframe: Returning sp = %#lx\n", (unsigned long)sp); | |
209 | return (void __user *) sp; /* Stacks grow up. Fun. */ | |
210 | } | |
211 | ||
212 | static long | |
213 | setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs, int in_syscall) | |
214 | ||
215 | { | |
216 | unsigned long flags = 0; | |
217 | long err = 0; | |
218 | ||
219 | if (on_sig_stack((unsigned long) sc)) | |
220 | flags |= PARISC_SC_FLAG_ONSTACK; | |
221 | if (in_syscall) { | |
222 | flags |= PARISC_SC_FLAG_IN_SYSCALL; | |
223 | /* regs->iaoq is undefined in the syscall return path */ | |
224 | err |= __put_user(regs->gr[31], &sc->sc_iaoq[0]); | |
225 | err |= __put_user(regs->gr[31]+4, &sc->sc_iaoq[1]); | |
226 | err |= __put_user(regs->sr[3], &sc->sc_iasq[0]); | |
227 | err |= __put_user(regs->sr[3], &sc->sc_iasq[1]); | |
228 | DBG(1,"setup_sigcontext: iaoq %#lx / %#lx (in syscall)\n", | |
229 | regs->gr[31], regs->gr[31]+4); | |
230 | } else { | |
231 | err |= __copy_to_user(sc->sc_iaoq, regs->iaoq, sizeof(regs->iaoq)); | |
232 | err |= __copy_to_user(sc->sc_iasq, regs->iasq, sizeof(regs->iasq)); | |
233 | DBG(1,"setup_sigcontext: iaoq %#lx / %#lx (not in syscall)\n", | |
234 | regs->iaoq[0], regs->iaoq[1]); | |
235 | } | |
236 | ||
237 | err |= __put_user(flags, &sc->sc_flags); | |
238 | err |= __copy_to_user(sc->sc_gr, regs->gr, sizeof(regs->gr)); | |
239 | err |= __copy_to_user(sc->sc_fr, regs->fr, sizeof(regs->fr)); | |
240 | err |= __put_user(regs->sar, &sc->sc_sar); | |
241 | DBG(1,"setup_sigcontext: r28 is %ld\n", regs->gr[28]); | |
242 | ||
243 | return err; | |
244 | } | |
245 | ||
246 | static long | |
247 | setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info, | |
248 | sigset_t *set, struct pt_regs *regs, int in_syscall) | |
249 | { | |
250 | struct rt_sigframe __user *frame; | |
251 | unsigned long rp, usp; | |
252 | unsigned long haddr, sigframe_size; | |
1da177e4 | 253 | int err = 0; |
a8f44e38 | 254 | #ifdef CONFIG_64BIT |
1da177e4 LT |
255 | compat_int_t compat_val; |
256 | struct compat_rt_sigframe __user * compat_frame; | |
257 | compat_sigset_t compat_set; | |
258 | #endif | |
259 | ||
260 | usp = (regs->gr[30] & ~(0x01UL)); | |
261 | /*FIXME: frame_size parameter is unused, remove it. */ | |
262 | frame = get_sigframe(ka, usp, sizeof(*frame)); | |
263 | ||
264 | DBG(1,"SETUP_RT_FRAME: START\n"); | |
265 | DBG(1,"setup_rt_frame: frame %p info %p\n", frame, info); | |
266 | ||
267 | ||
a8f44e38 | 268 | #ifdef CONFIG_64BIT |
1da177e4 LT |
269 | |
270 | compat_frame = (struct compat_rt_sigframe __user *)frame; | |
271 | ||
a3ea84fa | 272 | if (is_compat_task()) { |
1da177e4 | 273 | DBG(1,"setup_rt_frame: frame->info = 0x%p\n", &compat_frame->info); |
f671c45d | 274 | err |= copy_siginfo_to_user32(&compat_frame->info, info); |
1da177e4 LT |
275 | DBG(1,"SETUP_RT_FRAME: 1\n"); |
276 | compat_val = (compat_int_t)current->sas_ss_sp; | |
277 | err |= __put_user(compat_val, &compat_frame->uc.uc_stack.ss_sp); | |
278 | DBG(1,"SETUP_RT_FRAME: 2\n"); | |
279 | compat_val = (compat_int_t)current->sas_ss_size; | |
280 | err |= __put_user(compat_val, &compat_frame->uc.uc_stack.ss_size); | |
281 | DBG(1,"SETUP_RT_FRAME: 3\n"); | |
282 | compat_val = sas_ss_flags(regs->gr[30]); | |
283 | err |= __put_user(compat_val, &compat_frame->uc.uc_stack.ss_flags); | |
284 | DBG(1,"setup_rt_frame: frame->uc = 0x%p\n", &compat_frame->uc); | |
285 | DBG(1,"setup_rt_frame: frame->uc.uc_mcontext = 0x%p\n", &compat_frame->uc.uc_mcontext); | |
286 | err |= setup_sigcontext32(&compat_frame->uc.uc_mcontext, | |
287 | &compat_frame->regs, regs, in_syscall); | |
288 | sigset_64to32(&compat_set,set); | |
289 | err |= __copy_to_user(&compat_frame->uc.uc_sigmask, &compat_set, sizeof(compat_set)); | |
290 | } else | |
291 | #endif | |
292 | { | |
293 | DBG(1,"setup_rt_frame: frame->info = 0x%p\n", &frame->info); | |
294 | err |= copy_siginfo_to_user(&frame->info, info); | |
295 | err |= __put_user(current->sas_ss_sp, &frame->uc.uc_stack.ss_sp); | |
296 | err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size); | |
297 | err |= __put_user(sas_ss_flags(regs->gr[30]), | |
298 | &frame->uc.uc_stack.ss_flags); | |
299 | DBG(1,"setup_rt_frame: frame->uc = 0x%p\n", &frame->uc); | |
300 | DBG(1,"setup_rt_frame: frame->uc.uc_mcontext = 0x%p\n", &frame->uc.uc_mcontext); | |
301 | err |= setup_sigcontext(&frame->uc.uc_mcontext, regs, in_syscall); | |
302 | /* FIXME: Should probably be converted aswell for the compat case */ | |
303 | err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set)); | |
304 | } | |
305 | ||
306 | if (err) | |
307 | goto give_sigsegv; | |
308 | ||
309 | /* Set up to return from userspace. If provided, use a stub | |
310 | already in userspace. The first words of tramp are used to | |
311 | save the previous sigrestartblock trampoline that might be | |
312 | on the stack. We start the sigreturn trampoline at | |
313 | SIGRESTARTBLOCK_TRAMP+X. */ | |
314 | err |= __put_user(in_syscall ? INSN_LDI_R25_1 : INSN_LDI_R25_0, | |
315 | &frame->tramp[SIGRESTARTBLOCK_TRAMP+0]); | |
316 | err |= __put_user(INSN_LDI_R20, | |
317 | &frame->tramp[SIGRESTARTBLOCK_TRAMP+1]); | |
318 | err |= __put_user(INSN_BLE_SR2_R0, | |
319 | &frame->tramp[SIGRESTARTBLOCK_TRAMP+2]); | |
320 | err |= __put_user(INSN_NOP, &frame->tramp[SIGRESTARTBLOCK_TRAMP+3]); | |
321 | ||
322 | #if DEBUG_SIG | |
323 | /* Assert that we're flushing in the correct space... */ | |
324 | { | |
325 | int sid; | |
326 | asm ("mfsp %%sr3,%0" : "=r" (sid)); | |
327 | DBG(1,"setup_rt_frame: Flushing 64 bytes at space %#x offset %p\n", | |
328 | sid, frame->tramp); | |
329 | } | |
330 | #endif | |
331 | ||
332 | flush_user_dcache_range((unsigned long) &frame->tramp[0], | |
333 | (unsigned long) &frame->tramp[TRAMP_SIZE]); | |
334 | flush_user_icache_range((unsigned long) &frame->tramp[0], | |
335 | (unsigned long) &frame->tramp[TRAMP_SIZE]); | |
336 | ||
efad798b | 337 | /* TRAMP Words 0-4, Length 5 = SIGRESTARTBLOCK_TRAMP |
1da177e4 LT |
338 | * TRAMP Words 5-9, Length 4 = SIGRETURN_TRAMP |
339 | * So the SIGRETURN_TRAMP is at the end of SIGRESTARTBLOCK_TRAMP | |
340 | */ | |
341 | rp = (unsigned long) &frame->tramp[SIGRESTARTBLOCK_TRAMP]; | |
342 | ||
343 | if (err) | |
344 | goto give_sigsegv; | |
345 | ||
346 | haddr = A(ka->sa.sa_handler); | |
347 | /* The sa_handler may be a pointer to a function descriptor */ | |
a8f44e38 | 348 | #ifdef CONFIG_64BIT |
a3ea84fa | 349 | if (is_compat_task()) { |
1da177e4 LT |
350 | #endif |
351 | if (haddr & PA_PLABEL_FDESC) { | |
352 | Elf32_Fdesc fdesc; | |
353 | Elf32_Fdesc __user *ufdesc = (Elf32_Fdesc __user *)A(haddr & ~3); | |
354 | ||
355 | err = __copy_from_user(&fdesc, ufdesc, sizeof(fdesc)); | |
356 | ||
357 | if (err) | |
358 | goto give_sigsegv; | |
359 | ||
360 | haddr = fdesc.addr; | |
361 | regs->gr[19] = fdesc.gp; | |
362 | } | |
a8f44e38 | 363 | #ifdef CONFIG_64BIT |
1da177e4 LT |
364 | } else { |
365 | Elf64_Fdesc fdesc; | |
366 | Elf64_Fdesc __user *ufdesc = (Elf64_Fdesc __user *)A(haddr & ~3); | |
367 | ||
368 | err = __copy_from_user(&fdesc, ufdesc, sizeof(fdesc)); | |
369 | ||
370 | if (err) | |
371 | goto give_sigsegv; | |
372 | ||
373 | haddr = fdesc.addr; | |
374 | regs->gr[19] = fdesc.gp; | |
375 | DBG(1,"setup_rt_frame: 64 bit signal, exe=%#lx, r19=%#lx, in_syscall=%d\n", | |
376 | haddr, regs->gr[19], in_syscall); | |
377 | } | |
378 | #endif | |
379 | ||
380 | /* The syscall return path will create IAOQ values from r31. | |
381 | */ | |
382 | sigframe_size = PARISC_RT_SIGFRAME_SIZE; | |
a8f44e38 | 383 | #ifdef CONFIG_64BIT |
a3ea84fa | 384 | if (is_compat_task()) |
1da177e4 LT |
385 | sigframe_size = PARISC_RT_SIGFRAME_SIZE32; |
386 | #endif | |
387 | if (in_syscall) { | |
388 | regs->gr[31] = haddr; | |
a8f44e38 | 389 | #ifdef CONFIG_64BIT |
df570b9c | 390 | if (!test_thread_flag(TIF_32BIT)) |
1da177e4 LT |
391 | sigframe_size |= 1; |
392 | #endif | |
393 | } else { | |
394 | unsigned long psw = USER_PSW; | |
a8f44e38 | 395 | #ifdef CONFIG_64BIT |
df570b9c | 396 | if (!test_thread_flag(TIF_32BIT)) |
1da177e4 LT |
397 | psw |= PSW_W; |
398 | #endif | |
399 | ||
400 | /* If we are singlestepping, arrange a trap to be delivered | |
401 | when we return to userspace. Note the semantics -- we | |
402 | should trap before the first insn in the handler is | |
403 | executed. Ref: | |
404 | http://sources.redhat.com/ml/gdb/2004-11/msg00245.html | |
405 | */ | |
406 | if (pa_psw(current)->r) { | |
407 | pa_psw(current)->r = 0; | |
408 | psw |= PSW_R; | |
409 | mtctl(-1, 0); | |
410 | } | |
411 | ||
412 | regs->gr[0] = psw; | |
413 | regs->iaoq[0] = haddr | 3; | |
414 | regs->iaoq[1] = regs->iaoq[0] + 4; | |
415 | } | |
416 | ||
417 | regs->gr[2] = rp; /* userland return pointer */ | |
418 | regs->gr[26] = sig; /* signal number */ | |
419 | ||
a8f44e38 | 420 | #ifdef CONFIG_64BIT |
a3ea84fa | 421 | if (is_compat_task()) { |
1da177e4 LT |
422 | regs->gr[25] = A(&compat_frame->info); /* siginfo pointer */ |
423 | regs->gr[24] = A(&compat_frame->uc); /* ucontext pointer */ | |
424 | } else | |
425 | #endif | |
426 | { | |
427 | regs->gr[25] = A(&frame->info); /* siginfo pointer */ | |
428 | regs->gr[24] = A(&frame->uc); /* ucontext pointer */ | |
429 | } | |
430 | ||
431 | DBG(1,"setup_rt_frame: making sigreturn frame: %#lx + %#lx = %#lx\n", | |
432 | regs->gr[30], sigframe_size, | |
433 | regs->gr[30] + sigframe_size); | |
434 | /* Raise the user stack pointer to make a proper call frame. */ | |
435 | regs->gr[30] = (A(frame) + sigframe_size); | |
436 | ||
437 | ||
438 | DBG(1,"setup_rt_frame: sig deliver (%s,%d) frame=0x%p sp=%#lx iaoq=%#lx/%#lx rp=%#lx\n", | |
439 | current->comm, current->pid, frame, regs->gr[30], | |
440 | regs->iaoq[0], regs->iaoq[1], rp); | |
441 | ||
442 | return 1; | |
443 | ||
444 | give_sigsegv: | |
445 | DBG(1,"setup_rt_frame: sending SIGSEGV\n"); | |
40c72f20 | 446 | force_sigsegv(sig, current); |
1da177e4 LT |
447 | return 0; |
448 | } | |
449 | ||
450 | /* | |
451 | * OK, we're invoking a handler. | |
452 | */ | |
453 | ||
454 | static long | |
455 | handle_signal(unsigned long sig, siginfo_t *info, struct k_sigaction *ka, | |
456 | sigset_t *oldset, struct pt_regs *regs, int in_syscall) | |
457 | { | |
458 | DBG(1,"handle_signal: sig=%ld, ka=%p, info=%p, oldset=%p, regs=%p\n", | |
459 | sig, ka, info, oldset, regs); | |
460 | ||
461 | /* Set up the stack frame */ | |
462 | if (!setup_rt_frame(sig, ka, info, oldset, regs, in_syscall)) | |
463 | return 0; | |
464 | ||
69be8f18 SR |
465 | spin_lock_irq(¤t->sighand->siglock); |
466 | sigorsets(¤t->blocked,¤t->blocked,&ka->sa.sa_mask); | |
467 | if (!(ka->sa.sa_flags & SA_NODEFER)) | |
1da177e4 | 468 | sigaddset(¤t->blocked,sig); |
69be8f18 SR |
469 | recalc_sigpending(); |
470 | spin_unlock_irq(¤t->sighand->siglock); | |
1da177e4 LT |
471 | return 1; |
472 | } | |
473 | ||
2b163b71 KM |
474 | static inline void |
475 | syscall_restart(struct pt_regs *regs, struct k_sigaction *ka) | |
476 | { | |
477 | /* Check the return code */ | |
478 | switch (regs->gr[28]) { | |
479 | case -ERESTART_RESTARTBLOCK: | |
480 | current_thread_info()->restart_block.fn = | |
481 | do_no_restart_syscall; | |
482 | case -ERESTARTNOHAND: | |
483 | DBG(1,"ERESTARTNOHAND: returning -EINTR\n"); | |
484 | regs->gr[28] = -EINTR; | |
485 | break; | |
486 | ||
487 | case -ERESTARTSYS: | |
488 | if (!(ka->sa.sa_flags & SA_RESTART)) { | |
489 | DBG(1,"ERESTARTSYS: putting -EINTR\n"); | |
490 | regs->gr[28] = -EINTR; | |
491 | break; | |
492 | } | |
493 | /* fallthrough */ | |
494 | case -ERESTARTNOINTR: | |
495 | /* A syscall is just a branch, so all | |
496 | * we have to do is fiddle the return pointer. | |
497 | */ | |
498 | regs->gr[31] -= 8; /* delayed branching */ | |
499 | /* Preserve original r28. */ | |
500 | regs->gr[28] = regs->orig_r28; | |
501 | break; | |
502 | } | |
503 | } | |
504 | ||
505 | static inline void | |
506 | insert_restart_trampoline(struct pt_regs *regs) | |
507 | { | |
508 | switch(regs->gr[28]) { | |
509 | case -ERESTART_RESTARTBLOCK: { | |
510 | /* Restart the system call - no handlers present */ | |
511 | unsigned int *usp = (unsigned int *)regs->gr[30]; | |
512 | ||
513 | /* Setup a trampoline to restart the syscall | |
514 | * with __NR_restart_syscall | |
515 | * | |
516 | * 0: <return address (orig r31)> | |
517 | * 4: <2nd half for 64-bit> | |
518 | * 8: ldw 0(%sp), %r31 | |
519 | * 12: be 0x100(%sr2, %r0) | |
520 | * 16: ldi __NR_restart_syscall, %r20 | |
521 | */ | |
522 | #ifdef CONFIG_64BIT | |
523 | put_user(regs->gr[31] >> 32, &usp[0]); | |
524 | put_user(regs->gr[31] & 0xffffffff, &usp[1]); | |
525 | put_user(0x0fc010df, &usp[2]); | |
526 | #else | |
527 | put_user(regs->gr[31], &usp[0]); | |
528 | put_user(0x0fc0109f, &usp[2]); | |
529 | #endif | |
530 | put_user(0xe0008200, &usp[3]); | |
531 | put_user(0x34140000, &usp[4]); | |
532 | ||
533 | /* Stack is 64-byte aligned, and we only need | |
534 | * to flush 1 cache line. | |
535 | * Flushing one cacheline is cheap. | |
536 | * "sync" on bigger (> 4 way) boxes is not. | |
537 | */ | |
cf39cc3b KM |
538 | flush_user_dcache_range(regs->gr[30], regs->gr[30] + 4); |
539 | flush_user_icache_range(regs->gr[30], regs->gr[30] + 4); | |
2b163b71 KM |
540 | |
541 | regs->gr[31] = regs->gr[30] + 8; | |
542 | /* Preserve original r28. */ | |
543 | regs->gr[28] = regs->orig_r28; | |
544 | ||
545 | return; | |
546 | } | |
547 | case -ERESTARTNOHAND: | |
548 | case -ERESTARTSYS: | |
549 | case -ERESTARTNOINTR: { | |
550 | /* Hooray for delayed branching. We don't | |
551 | * have to restore %r20 (the system call | |
552 | * number) because it gets loaded in the delay | |
553 | * slot of the branch external instruction. | |
554 | */ | |
555 | regs->gr[31] -= 8; | |
556 | /* Preserve original r28. */ | |
557 | regs->gr[28] = regs->orig_r28; | |
558 | ||
559 | return; | |
560 | } | |
561 | default: | |
562 | break; | |
563 | } | |
564 | } | |
565 | ||
1da177e4 LT |
566 | /* |
567 | * Note that 'init' is a special process: it doesn't get signals it doesn't | |
568 | * want to handle. Thus you cannot kill init even with a SIGKILL even by | |
569 | * mistake. | |
570 | * | |
571 | * We need to be able to restore the syscall arguments (r21-r26) to | |
572 | * restart syscalls. Thus, the syscall path should save them in the | |
573 | * pt_regs structure (it's okay to do so since they are caller-save | |
574 | * registers). As noted below, the syscall number gets restored for | |
575 | * us due to the magic of delayed branching. | |
576 | */ | |
4650f0a5 KM |
577 | asmlinkage void |
578 | do_signal(struct pt_regs *regs, long in_syscall) | |
1da177e4 LT |
579 | { |
580 | siginfo_t info; | |
581 | struct k_sigaction ka; | |
582 | int signr; | |
4650f0a5 | 583 | sigset_t *oldset; |
1da177e4 LT |
584 | |
585 | DBG(1,"\ndo_signal: oldset=0x%p, regs=0x%p, sr7 %#lx, in_syscall=%d\n", | |
586 | oldset, regs, regs->sr[7], in_syscall); | |
587 | ||
588 | /* Everyone else checks to see if they are in kernel mode at | |
589 | this point and exits if that's the case. I'm not sure why | |
590 | we would be called in that case, but for some reason we | |
591 | are. */ | |
592 | ||
4650f0a5 KM |
593 | if (test_thread_flag(TIF_RESTORE_SIGMASK)) |
594 | oldset = ¤t->saved_sigmask; | |
595 | else | |
1da177e4 LT |
596 | oldset = ¤t->blocked; |
597 | ||
598 | DBG(1,"do_signal: oldset %08lx / %08lx\n", | |
599 | oldset->sig[0], oldset->sig[1]); | |
600 | ||
601 | ||
602 | /* May need to force signal if handle_signal failed to deliver */ | |
603 | while (1) { | |
604 | ||
605 | signr = get_signal_to_deliver(&info, &ka, regs, NULL); | |
606 | DBG(3,"do_signal: signr = %d, regs->gr[28] = %ld\n", signr, regs->gr[28]); | |
607 | ||
608 | if (signr <= 0) | |
609 | break; | |
610 | ||
611 | /* Restart a system call if necessary. */ | |
2b163b71 KM |
612 | if (in_syscall) |
613 | syscall_restart(regs, &ka); | |
614 | ||
1da177e4 LT |
615 | /* Whee! Actually deliver the signal. If the |
616 | delivery failed, we need to continue to iterate in | |
617 | this loop so we can deliver the SIGSEGV... */ | |
2b163b71 KM |
618 | if (handle_signal(signr, &info, &ka, oldset, |
619 | regs, in_syscall)) { | |
1da177e4 LT |
620 | DBG(1,KERN_DEBUG "do_signal: Exit (success), regs->gr[28] = %ld\n", |
621 | regs->gr[28]); | |
4650f0a5 KM |
622 | if (test_thread_flag(TIF_RESTORE_SIGMASK)) |
623 | clear_thread_flag(TIF_RESTORE_SIGMASK); | |
624 | return; | |
1da177e4 LT |
625 | } |
626 | } | |
627 | /* end of while(1) looping forever if we can't force a signal */ | |
628 | ||
629 | /* Did we come from a system call? */ | |
2b163b71 KM |
630 | if (in_syscall) |
631 | insert_restart_trampoline(regs); | |
1da177e4 LT |
632 | |
633 | DBG(1,"do_signal: Exit (not delivered), regs->gr[28] = %ld\n", | |
634 | regs->gr[28]); | |
635 | ||
4650f0a5 KM |
636 | if (test_thread_flag(TIF_RESTORE_SIGMASK)) { |
637 | clear_thread_flag(TIF_RESTORE_SIGMASK); | |
638 | sigprocmask(SIG_SETMASK, ¤t->saved_sigmask, NULL); | |
639 | } | |
640 | ||
641 | return; | |
642 | } | |
643 | ||
644 | void do_notify_resume(struct pt_regs *regs, long in_syscall) | |
645 | { | |
646 | if (test_thread_flag(TIF_SIGPENDING) || | |
647 | test_thread_flag(TIF_RESTORE_SIGMASK)) | |
648 | do_signal(regs, in_syscall); | |
d0420c83 DH |
649 | |
650 | if (test_thread_flag(TIF_NOTIFY_RESUME)) { | |
651 | clear_thread_flag(TIF_NOTIFY_RESUME); | |
652 | tracehook_notify_resume(regs); | |
ee18d64c DH |
653 | if (current->replacement_session_keyring) |
654 | key_replace_session_keyring(); | |
d0420c83 | 655 | } |
1da177e4 | 656 | } |