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> | |
ecf02de5 | 24 | #include <linux/tracehook.h> |
1da177e4 LT |
25 | #include <linux/unistd.h> |
26 | #include <linux/stddef.h> | |
27 | #include <linux/compat.h> | |
28 | #include <linux/elf.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 | |
1da177e4 LT |
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 | ||
1da177e4 LT |
51 | /* gcc will complain if a pointer is cast to an integer of different |
52 | * size. If you really need to do this (and we do for an ELF32 user | |
53 | * application in an ELF64 kernel) then you have to do a cast to an | |
54 | * integer of the same size first. The A() macro accomplishes | |
55 | * this. */ | |
56 | #define A(__x) ((unsigned long)(__x)) | |
57 | ||
1da177e4 LT |
58 | /* |
59 | * Do a signal return - restore sigcontext. | |
60 | */ | |
61 | ||
62 | /* Trampoline for calling rt_sigreturn() */ | |
63 | #define INSN_LDI_R25_0 0x34190000 /* ldi 0,%r25 (in_syscall=0) */ | |
64 | #define INSN_LDI_R25_1 0x34190002 /* ldi 1,%r25 (in_syscall=1) */ | |
65 | #define INSN_LDI_R20 0x3414015a /* ldi __NR_rt_sigreturn,%r20 */ | |
66 | #define INSN_BLE_SR2_R0 0xe4008200 /* be,l 0x100(%sr2,%r0),%sr0,%r31 */ | |
67 | #define INSN_NOP 0x08000240 /* nop */ | |
68 | /* For debugging */ | |
69 | #define INSN_DIE_HORRIBLY 0x68000ccc /* stw %r0,0x666(%sr0,%r0) */ | |
70 | ||
71 | static long | |
72 | restore_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs) | |
73 | { | |
74 | long err = 0; | |
75 | ||
76 | err |= __copy_from_user(regs->gr, sc->sc_gr, sizeof(regs->gr)); | |
77 | err |= __copy_from_user(regs->fr, sc->sc_fr, sizeof(regs->fr)); | |
78 | err |= __copy_from_user(regs->iaoq, sc->sc_iaoq, sizeof(regs->iaoq)); | |
79 | err |= __copy_from_user(regs->iasq, sc->sc_iasq, sizeof(regs->iasq)); | |
80 | err |= __get_user(regs->sar, &sc->sc_sar); | |
8e33a52f | 81 | DBG(2,"restore_sigcontext: iaoq is %#lx / %#lx\n", |
1da177e4 LT |
82 | regs->iaoq[0],regs->iaoq[1]); |
83 | DBG(2,"restore_sigcontext: r28 is %ld\n", regs->gr[28]); | |
84 | return err; | |
85 | } | |
86 | ||
87 | void | |
88 | sys_rt_sigreturn(struct pt_regs *regs, int in_syscall) | |
89 | { | |
90 | struct rt_sigframe __user *frame; | |
1da177e4 LT |
91 | sigset_t set; |
92 | unsigned long usp = (regs->gr[30] & ~(0x01UL)); | |
93 | unsigned long sigframe_size = PARISC_RT_SIGFRAME_SIZE; | |
a8f44e38 | 94 | #ifdef CONFIG_64BIT |
1da177e4 LT |
95 | compat_sigset_t compat_set; |
96 | struct compat_rt_sigframe __user * compat_frame; | |
97 | ||
a3ea84fa | 98 | if (is_compat_task()) |
1da177e4 LT |
99 | sigframe_size = PARISC_RT_SIGFRAME_SIZE32; |
100 | #endif | |
101 | ||
85a847ff | 102 | current_thread_info()->restart_block.fn = do_no_restart_syscall; |
1da177e4 LT |
103 | |
104 | /* Unwind the user stack to get the rt_sigframe structure. */ | |
105 | frame = (struct rt_sigframe __user *) | |
106 | (usp - sigframe_size); | |
107 | DBG(2,"sys_rt_sigreturn: frame is %p\n", frame); | |
108 | ||
00df111e AV |
109 | regs->orig_r28 = 1; /* no restarts for sigreturn */ |
110 | ||
a8f44e38 | 111 | #ifdef CONFIG_64BIT |
1da177e4 LT |
112 | compat_frame = (struct compat_rt_sigframe __user *)frame; |
113 | ||
a3ea84fa | 114 | if (is_compat_task()) { |
1da177e4 LT |
115 | DBG(2,"sys_rt_sigreturn: ELF32 process.\n"); |
116 | if (__copy_from_user(&compat_set, &compat_frame->uc.uc_sigmask, sizeof(compat_set))) | |
117 | goto give_sigsegv; | |
118 | sigset_32to64(&set,&compat_set); | |
119 | } else | |
120 | #endif | |
121 | { | |
122 | if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set))) | |
123 | goto give_sigsegv; | |
124 | } | |
125 | ||
ade7728b | 126 | set_current_blocked(&set); |
1da177e4 LT |
127 | |
128 | /* Good thing we saved the old gr[30], eh? */ | |
a8f44e38 | 129 | #ifdef CONFIG_64BIT |
a3ea84fa | 130 | if (is_compat_task()) { |
1da177e4 LT |
131 | DBG(1,"sys_rt_sigreturn: compat_frame->uc.uc_mcontext 0x%p\n", |
132 | &compat_frame->uc.uc_mcontext); | |
133 | // FIXME: Load upper half from register file | |
134 | if (restore_sigcontext32(&compat_frame->uc.uc_mcontext, | |
135 | &compat_frame->regs, regs)) | |
136 | goto give_sigsegv; | |
137 | DBG(1,"sys_rt_sigreturn: usp %#08lx stack 0x%p\n", | |
138 | usp, &compat_frame->uc.uc_stack); | |
6e26aab9 | 139 | if (compat_restore_altstack(&compat_frame->uc.uc_stack)) |
1da177e4 LT |
140 | goto give_sigsegv; |
141 | } else | |
142 | #endif | |
143 | { | |
144 | DBG(1,"sys_rt_sigreturn: frame->uc.uc_mcontext 0x%p\n", | |
145 | &frame->uc.uc_mcontext); | |
146 | if (restore_sigcontext(&frame->uc.uc_mcontext, regs)) | |
147 | goto give_sigsegv; | |
148 | DBG(1,"sys_rt_sigreturn: usp %#08lx stack 0x%p\n", | |
149 | usp, &frame->uc.uc_stack); | |
6e26aab9 | 150 | if (restore_altstack(&frame->uc.uc_stack)) |
1da177e4 LT |
151 | goto give_sigsegv; |
152 | } | |
153 | ||
154 | ||
155 | ||
156 | /* If we are on the syscall path IAOQ will not be restored, and | |
157 | * if we are on the interrupt path we must not corrupt gr31. | |
158 | */ | |
159 | if (in_syscall) | |
160 | regs->gr[31] = regs->iaoq[0]; | |
161 | #if DEBUG_SIG | |
162 | DBG(1,"sys_rt_sigreturn: returning to %#lx, DUMPING REGS:\n", regs->iaoq[0]); | |
163 | show_regs(regs); | |
164 | #endif | |
165 | return; | |
166 | ||
167 | give_sigsegv: | |
168 | DBG(1,"sys_rt_sigreturn: Sending SIGSEGV\n"); | |
67bace72 | 169 | force_sig(SIGSEGV, current); |
1da177e4 LT |
170 | return; |
171 | } | |
172 | ||
173 | /* | |
174 | * Set up a signal frame. | |
175 | */ | |
176 | ||
177 | static inline void __user * | |
178 | get_sigframe(struct k_sigaction *ka, unsigned long sp, size_t frame_size) | |
179 | { | |
180 | /*FIXME: ELF32 vs. ELF64 has different frame_size, but since we | |
181 | don't use the parameter it doesn't matter */ | |
182 | ||
183 | DBG(1,"get_sigframe: ka = %#lx, sp = %#lx, frame_size = %#lx\n", | |
184 | (unsigned long)ka, sp, frame_size); | |
185 | ||
ad30f3ff JDA |
186 | /* Align alternate stack and reserve 64 bytes for the signal |
187 | handler's frame marker. */ | |
d09042da | 188 | if ((ka->sa.sa_flags & SA_ONSTACK) != 0 && ! sas_ss_flags(sp)) |
ad30f3ff | 189 | sp = (current->sas_ss_sp + 0x7f) & ~0x3f; /* Stacks grow up! */ |
1da177e4 LT |
190 | |
191 | DBG(1,"get_sigframe: Returning sp = %#lx\n", (unsigned long)sp); | |
192 | return (void __user *) sp; /* Stacks grow up. Fun. */ | |
193 | } | |
194 | ||
195 | static long | |
196 | setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs, int in_syscall) | |
197 | ||
198 | { | |
199 | unsigned long flags = 0; | |
200 | long err = 0; | |
201 | ||
202 | if (on_sig_stack((unsigned long) sc)) | |
203 | flags |= PARISC_SC_FLAG_ONSTACK; | |
204 | if (in_syscall) { | |
205 | flags |= PARISC_SC_FLAG_IN_SYSCALL; | |
206 | /* regs->iaoq is undefined in the syscall return path */ | |
207 | err |= __put_user(regs->gr[31], &sc->sc_iaoq[0]); | |
208 | err |= __put_user(regs->gr[31]+4, &sc->sc_iaoq[1]); | |
209 | err |= __put_user(regs->sr[3], &sc->sc_iasq[0]); | |
210 | err |= __put_user(regs->sr[3], &sc->sc_iasq[1]); | |
211 | DBG(1,"setup_sigcontext: iaoq %#lx / %#lx (in syscall)\n", | |
212 | regs->gr[31], regs->gr[31]+4); | |
213 | } else { | |
214 | err |= __copy_to_user(sc->sc_iaoq, regs->iaoq, sizeof(regs->iaoq)); | |
215 | err |= __copy_to_user(sc->sc_iasq, regs->iasq, sizeof(regs->iasq)); | |
216 | DBG(1,"setup_sigcontext: iaoq %#lx / %#lx (not in syscall)\n", | |
217 | regs->iaoq[0], regs->iaoq[1]); | |
218 | } | |
219 | ||
220 | err |= __put_user(flags, &sc->sc_flags); | |
221 | err |= __copy_to_user(sc->sc_gr, regs->gr, sizeof(regs->gr)); | |
222 | err |= __copy_to_user(sc->sc_fr, regs->fr, sizeof(regs->fr)); | |
223 | err |= __put_user(regs->sar, &sc->sc_sar); | |
224 | DBG(1,"setup_sigcontext: r28 is %ld\n", regs->gr[28]); | |
225 | ||
226 | return err; | |
227 | } | |
228 | ||
229 | static long | |
230 | setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info, | |
231 | sigset_t *set, struct pt_regs *regs, int in_syscall) | |
232 | { | |
233 | struct rt_sigframe __user *frame; | |
234 | unsigned long rp, usp; | |
235 | unsigned long haddr, sigframe_size; | |
1da177e4 | 236 | int err = 0; |
a8f44e38 | 237 | #ifdef CONFIG_64BIT |
1da177e4 LT |
238 | struct compat_rt_sigframe __user * compat_frame; |
239 | compat_sigset_t compat_set; | |
240 | #endif | |
241 | ||
242 | usp = (regs->gr[30] & ~(0x01UL)); | |
243 | /*FIXME: frame_size parameter is unused, remove it. */ | |
244 | frame = get_sigframe(ka, usp, sizeof(*frame)); | |
245 | ||
246 | DBG(1,"SETUP_RT_FRAME: START\n"); | |
247 | DBG(1,"setup_rt_frame: frame %p info %p\n", frame, info); | |
248 | ||
249 | ||
a8f44e38 | 250 | #ifdef CONFIG_64BIT |
1da177e4 LT |
251 | |
252 | compat_frame = (struct compat_rt_sigframe __user *)frame; | |
253 | ||
a3ea84fa | 254 | if (is_compat_task()) { |
1da177e4 | 255 | DBG(1,"setup_rt_frame: frame->info = 0x%p\n", &compat_frame->info); |
f671c45d | 256 | err |= copy_siginfo_to_user32(&compat_frame->info, info); |
6e26aab9 | 257 | err |= __compat_save_altstack( &compat_frame->uc.uc_stack, regs->gr[30]); |
1da177e4 LT |
258 | DBG(1,"setup_rt_frame: frame->uc = 0x%p\n", &compat_frame->uc); |
259 | DBG(1,"setup_rt_frame: frame->uc.uc_mcontext = 0x%p\n", &compat_frame->uc.uc_mcontext); | |
260 | err |= setup_sigcontext32(&compat_frame->uc.uc_mcontext, | |
261 | &compat_frame->regs, regs, in_syscall); | |
262 | sigset_64to32(&compat_set,set); | |
263 | err |= __copy_to_user(&compat_frame->uc.uc_sigmask, &compat_set, sizeof(compat_set)); | |
264 | } else | |
265 | #endif | |
266 | { | |
267 | DBG(1,"setup_rt_frame: frame->info = 0x%p\n", &frame->info); | |
268 | err |= copy_siginfo_to_user(&frame->info, info); | |
6e26aab9 | 269 | err |= __save_altstack(&frame->uc.uc_stack, regs->gr[30]); |
1da177e4 LT |
270 | DBG(1,"setup_rt_frame: frame->uc = 0x%p\n", &frame->uc); |
271 | DBG(1,"setup_rt_frame: frame->uc.uc_mcontext = 0x%p\n", &frame->uc.uc_mcontext); | |
272 | err |= setup_sigcontext(&frame->uc.uc_mcontext, regs, in_syscall); | |
25985edc | 273 | /* FIXME: Should probably be converted as well for the compat case */ |
1da177e4 LT |
274 | err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set)); |
275 | } | |
276 | ||
277 | if (err) | |
278 | goto give_sigsegv; | |
279 | ||
280 | /* Set up to return from userspace. If provided, use a stub | |
281 | already in userspace. The first words of tramp are used to | |
282 | save the previous sigrestartblock trampoline that might be | |
283 | on the stack. We start the sigreturn trampoline at | |
284 | SIGRESTARTBLOCK_TRAMP+X. */ | |
285 | err |= __put_user(in_syscall ? INSN_LDI_R25_1 : INSN_LDI_R25_0, | |
286 | &frame->tramp[SIGRESTARTBLOCK_TRAMP+0]); | |
287 | err |= __put_user(INSN_LDI_R20, | |
288 | &frame->tramp[SIGRESTARTBLOCK_TRAMP+1]); | |
289 | err |= __put_user(INSN_BLE_SR2_R0, | |
290 | &frame->tramp[SIGRESTARTBLOCK_TRAMP+2]); | |
291 | err |= __put_user(INSN_NOP, &frame->tramp[SIGRESTARTBLOCK_TRAMP+3]); | |
292 | ||
293 | #if DEBUG_SIG | |
294 | /* Assert that we're flushing in the correct space... */ | |
295 | { | |
45b6eff2 | 296 | unsigned long sid; |
1da177e4 LT |
297 | asm ("mfsp %%sr3,%0" : "=r" (sid)); |
298 | DBG(1,"setup_rt_frame: Flushing 64 bytes at space %#x offset %p\n", | |
299 | sid, frame->tramp); | |
300 | } | |
301 | #endif | |
302 | ||
303 | flush_user_dcache_range((unsigned long) &frame->tramp[0], | |
304 | (unsigned long) &frame->tramp[TRAMP_SIZE]); | |
305 | flush_user_icache_range((unsigned long) &frame->tramp[0], | |
306 | (unsigned long) &frame->tramp[TRAMP_SIZE]); | |
307 | ||
efad798b | 308 | /* TRAMP Words 0-4, Length 5 = SIGRESTARTBLOCK_TRAMP |
1da177e4 LT |
309 | * TRAMP Words 5-9, Length 4 = SIGRETURN_TRAMP |
310 | * So the SIGRETURN_TRAMP is at the end of SIGRESTARTBLOCK_TRAMP | |
311 | */ | |
312 | rp = (unsigned long) &frame->tramp[SIGRESTARTBLOCK_TRAMP]; | |
313 | ||
314 | if (err) | |
315 | goto give_sigsegv; | |
316 | ||
317 | haddr = A(ka->sa.sa_handler); | |
318 | /* The sa_handler may be a pointer to a function descriptor */ | |
a8f44e38 | 319 | #ifdef CONFIG_64BIT |
a3ea84fa | 320 | if (is_compat_task()) { |
1da177e4 LT |
321 | #endif |
322 | if (haddr & PA_PLABEL_FDESC) { | |
323 | Elf32_Fdesc fdesc; | |
324 | Elf32_Fdesc __user *ufdesc = (Elf32_Fdesc __user *)A(haddr & ~3); | |
325 | ||
326 | err = __copy_from_user(&fdesc, ufdesc, sizeof(fdesc)); | |
327 | ||
328 | if (err) | |
329 | goto give_sigsegv; | |
330 | ||
331 | haddr = fdesc.addr; | |
332 | regs->gr[19] = fdesc.gp; | |
333 | } | |
a8f44e38 | 334 | #ifdef CONFIG_64BIT |
1da177e4 LT |
335 | } else { |
336 | Elf64_Fdesc fdesc; | |
337 | Elf64_Fdesc __user *ufdesc = (Elf64_Fdesc __user *)A(haddr & ~3); | |
338 | ||
339 | err = __copy_from_user(&fdesc, ufdesc, sizeof(fdesc)); | |
340 | ||
341 | if (err) | |
342 | goto give_sigsegv; | |
343 | ||
344 | haddr = fdesc.addr; | |
345 | regs->gr[19] = fdesc.gp; | |
346 | DBG(1,"setup_rt_frame: 64 bit signal, exe=%#lx, r19=%#lx, in_syscall=%d\n", | |
347 | haddr, regs->gr[19], in_syscall); | |
348 | } | |
349 | #endif | |
350 | ||
351 | /* The syscall return path will create IAOQ values from r31. | |
352 | */ | |
353 | sigframe_size = PARISC_RT_SIGFRAME_SIZE; | |
a8f44e38 | 354 | #ifdef CONFIG_64BIT |
a3ea84fa | 355 | if (is_compat_task()) |
1da177e4 LT |
356 | sigframe_size = PARISC_RT_SIGFRAME_SIZE32; |
357 | #endif | |
358 | if (in_syscall) { | |
359 | regs->gr[31] = haddr; | |
a8f44e38 | 360 | #ifdef CONFIG_64BIT |
df570b9c | 361 | if (!test_thread_flag(TIF_32BIT)) |
1da177e4 LT |
362 | sigframe_size |= 1; |
363 | #endif | |
364 | } else { | |
365 | unsigned long psw = USER_PSW; | |
a8f44e38 | 366 | #ifdef CONFIG_64BIT |
df570b9c | 367 | if (!test_thread_flag(TIF_32BIT)) |
1da177e4 LT |
368 | psw |= PSW_W; |
369 | #endif | |
370 | ||
371 | /* If we are singlestepping, arrange a trap to be delivered | |
372 | when we return to userspace. Note the semantics -- we | |
373 | should trap before the first insn in the handler is | |
374 | executed. Ref: | |
375 | http://sources.redhat.com/ml/gdb/2004-11/msg00245.html | |
376 | */ | |
377 | if (pa_psw(current)->r) { | |
378 | pa_psw(current)->r = 0; | |
379 | psw |= PSW_R; | |
380 | mtctl(-1, 0); | |
381 | } | |
382 | ||
383 | regs->gr[0] = psw; | |
384 | regs->iaoq[0] = haddr | 3; | |
385 | regs->iaoq[1] = regs->iaoq[0] + 4; | |
386 | } | |
387 | ||
388 | regs->gr[2] = rp; /* userland return pointer */ | |
389 | regs->gr[26] = sig; /* signal number */ | |
390 | ||
a8f44e38 | 391 | #ifdef CONFIG_64BIT |
a3ea84fa | 392 | if (is_compat_task()) { |
1da177e4 LT |
393 | regs->gr[25] = A(&compat_frame->info); /* siginfo pointer */ |
394 | regs->gr[24] = A(&compat_frame->uc); /* ucontext pointer */ | |
395 | } else | |
396 | #endif | |
397 | { | |
398 | regs->gr[25] = A(&frame->info); /* siginfo pointer */ | |
399 | regs->gr[24] = A(&frame->uc); /* ucontext pointer */ | |
400 | } | |
401 | ||
402 | DBG(1,"setup_rt_frame: making sigreturn frame: %#lx + %#lx = %#lx\n", | |
403 | regs->gr[30], sigframe_size, | |
404 | regs->gr[30] + sigframe_size); | |
405 | /* Raise the user stack pointer to make a proper call frame. */ | |
406 | regs->gr[30] = (A(frame) + sigframe_size); | |
407 | ||
408 | ||
409 | DBG(1,"setup_rt_frame: sig deliver (%s,%d) frame=0x%p sp=%#lx iaoq=%#lx/%#lx rp=%#lx\n", | |
410 | current->comm, current->pid, frame, regs->gr[30], | |
411 | regs->iaoq[0], regs->iaoq[1], rp); | |
412 | ||
413 | return 1; | |
414 | ||
415 | give_sigsegv: | |
416 | DBG(1,"setup_rt_frame: sending SIGSEGV\n"); | |
40c72f20 | 417 | force_sigsegv(sig, current); |
1da177e4 LT |
418 | return 0; |
419 | } | |
420 | ||
421 | /* | |
422 | * OK, we're invoking a handler. | |
423 | */ | |
424 | ||
e3b880c6 | 425 | static void |
1da177e4 | 426 | handle_signal(unsigned long sig, siginfo_t *info, struct k_sigaction *ka, |
b7f9a11a | 427 | struct pt_regs *regs, int in_syscall) |
1da177e4 | 428 | { |
b7f9a11a | 429 | sigset_t *oldset = sigmask_to_save(); |
1da177e4 LT |
430 | DBG(1,"handle_signal: sig=%ld, ka=%p, info=%p, oldset=%p, regs=%p\n", |
431 | sig, ka, info, oldset, regs); | |
432 | ||
433 | /* Set up the stack frame */ | |
434 | if (!setup_rt_frame(sig, ka, info, oldset, regs, in_syscall)) | |
e3b880c6 | 435 | return; |
1da177e4 | 436 | |
efee984c | 437 | signal_delivered(sig, info, ka, regs, |
22a8cdd6 KM |
438 | test_thread_flag(TIF_SINGLESTEP) || |
439 | test_thread_flag(TIF_BLOCKSTEP)); | |
ecf02de5 | 440 | |
a610d6e6 AV |
441 | DBG(1,KERN_DEBUG "do_signal: Exit (success), regs->gr[28] = %ld\n", |
442 | regs->gr[28]); | |
1da177e4 LT |
443 | } |
444 | ||
2b163b71 KM |
445 | static inline void |
446 | syscall_restart(struct pt_regs *regs, struct k_sigaction *ka) | |
447 | { | |
00df111e AV |
448 | if (regs->orig_r28) |
449 | return; | |
450 | regs->orig_r28 = 1; /* no more restarts */ | |
2b163b71 KM |
451 | /* Check the return code */ |
452 | switch (regs->gr[28]) { | |
453 | case -ERESTART_RESTARTBLOCK: | |
2b163b71 KM |
454 | case -ERESTARTNOHAND: |
455 | DBG(1,"ERESTARTNOHAND: returning -EINTR\n"); | |
456 | regs->gr[28] = -EINTR; | |
457 | break; | |
458 | ||
459 | case -ERESTARTSYS: | |
460 | if (!(ka->sa.sa_flags & SA_RESTART)) { | |
461 | DBG(1,"ERESTARTSYS: putting -EINTR\n"); | |
462 | regs->gr[28] = -EINTR; | |
463 | break; | |
464 | } | |
465 | /* fallthrough */ | |
466 | case -ERESTARTNOINTR: | |
467 | /* A syscall is just a branch, so all | |
468 | * we have to do is fiddle the return pointer. | |
469 | */ | |
470 | regs->gr[31] -= 8; /* delayed branching */ | |
2b163b71 KM |
471 | break; |
472 | } | |
473 | } | |
474 | ||
475 | static inline void | |
476 | insert_restart_trampoline(struct pt_regs *regs) | |
477 | { | |
00df111e AV |
478 | if (regs->orig_r28) |
479 | return; | |
480 | regs->orig_r28 = 1; /* no more restarts */ | |
2b163b71 KM |
481 | switch(regs->gr[28]) { |
482 | case -ERESTART_RESTARTBLOCK: { | |
483 | /* Restart the system call - no handlers present */ | |
484 | unsigned int *usp = (unsigned int *)regs->gr[30]; | |
485 | ||
486 | /* Setup a trampoline to restart the syscall | |
487 | * with __NR_restart_syscall | |
488 | * | |
489 | * 0: <return address (orig r31)> | |
490 | * 4: <2nd half for 64-bit> | |
491 | * 8: ldw 0(%sp), %r31 | |
492 | * 12: be 0x100(%sr2, %r0) | |
493 | * 16: ldi __NR_restart_syscall, %r20 | |
494 | */ | |
495 | #ifdef CONFIG_64BIT | |
496 | put_user(regs->gr[31] >> 32, &usp[0]); | |
497 | put_user(regs->gr[31] & 0xffffffff, &usp[1]); | |
498 | put_user(0x0fc010df, &usp[2]); | |
499 | #else | |
500 | put_user(regs->gr[31], &usp[0]); | |
501 | put_user(0x0fc0109f, &usp[2]); | |
502 | #endif | |
503 | put_user(0xe0008200, &usp[3]); | |
504 | put_user(0x34140000, &usp[4]); | |
505 | ||
506 | /* Stack is 64-byte aligned, and we only need | |
507 | * to flush 1 cache line. | |
508 | * Flushing one cacheline is cheap. | |
509 | * "sync" on bigger (> 4 way) boxes is not. | |
510 | */ | |
cf39cc3b KM |
511 | flush_user_dcache_range(regs->gr[30], regs->gr[30] + 4); |
512 | flush_user_icache_range(regs->gr[30], regs->gr[30] + 4); | |
2b163b71 KM |
513 | |
514 | regs->gr[31] = regs->gr[30] + 8; | |
2b163b71 KM |
515 | return; |
516 | } | |
517 | case -ERESTARTNOHAND: | |
518 | case -ERESTARTSYS: | |
519 | case -ERESTARTNOINTR: { | |
520 | /* Hooray for delayed branching. We don't | |
521 | * have to restore %r20 (the system call | |
522 | * number) because it gets loaded in the delay | |
523 | * slot of the branch external instruction. | |
524 | */ | |
525 | regs->gr[31] -= 8; | |
2b163b71 KM |
526 | return; |
527 | } | |
528 | default: | |
529 | break; | |
530 | } | |
531 | } | |
532 | ||
1da177e4 LT |
533 | /* |
534 | * Note that 'init' is a special process: it doesn't get signals it doesn't | |
535 | * want to handle. Thus you cannot kill init even with a SIGKILL even by | |
536 | * mistake. | |
537 | * | |
538 | * We need to be able to restore the syscall arguments (r21-r26) to | |
539 | * restart syscalls. Thus, the syscall path should save them in the | |
540 | * pt_regs structure (it's okay to do so since they are caller-save | |
541 | * registers). As noted below, the syscall number gets restored for | |
542 | * us due to the magic of delayed branching. | |
543 | */ | |
4650f0a5 KM |
544 | asmlinkage void |
545 | do_signal(struct pt_regs *regs, long in_syscall) | |
1da177e4 LT |
546 | { |
547 | siginfo_t info; | |
548 | struct k_sigaction ka; | |
549 | int signr; | |
550 | ||
b7f9a11a AV |
551 | DBG(1,"\ndo_signal: regs=0x%p, sr7 %#lx, in_syscall=%d\n", |
552 | regs, regs->sr[7], in_syscall); | |
1da177e4 | 553 | |
e3b880c6 AV |
554 | signr = get_signal_to_deliver(&info, &ka, regs, NULL); |
555 | DBG(3,"do_signal: signr = %d, regs->gr[28] = %ld\n", signr, regs->gr[28]); | |
1da177e4 | 556 | |
e3b880c6 | 557 | if (signr > 0) { |
1da177e4 | 558 | /* Restart a system call if necessary. */ |
2b163b71 KM |
559 | if (in_syscall) |
560 | syscall_restart(regs, &ka); | |
561 | ||
e3b880c6 AV |
562 | handle_signal(signr, &info, &ka, regs, in_syscall); |
563 | return; | |
1da177e4 | 564 | } |
1da177e4 LT |
565 | |
566 | /* Did we come from a system call? */ | |
2b163b71 KM |
567 | if (in_syscall) |
568 | insert_restart_trampoline(regs); | |
1da177e4 LT |
569 | |
570 | DBG(1,"do_signal: Exit (not delivered), regs->gr[28] = %ld\n", | |
571 | regs->gr[28]); | |
572 | ||
51a7b448 | 573 | restore_saved_sigmask(); |
4650f0a5 KM |
574 | } |
575 | ||
576 | void do_notify_resume(struct pt_regs *regs, long in_syscall) | |
577 | { | |
6fd84c08 | 578 | if (test_thread_flag(TIF_SIGPENDING)) |
4650f0a5 | 579 | do_signal(regs, in_syscall); |
d0420c83 DH |
580 | |
581 | if (test_thread_flag(TIF_NOTIFY_RESUME)) { | |
582 | clear_thread_flag(TIF_NOTIFY_RESUME); | |
583 | tracehook_notify_resume(regs); | |
584 | } | |
1da177e4 | 585 | } |