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b2441318 | 1 | // SPDX-License-Identifier: GPL-2.0 |
1da177e4 LT |
2 | /* |
3 | * linux/arch/parisc/kernel/signal.c: Architecture-specific signal | |
4 | * handling support. | |
5 | * | |
6 | * Copyright (C) 2000 David Huggins-Daines <dhd@debian.org> | |
7 | * Copyright (C) 2000 Linuxcare, Inc. | |
8 | * | |
9 | * Based on the ia64, i386, and alpha versions. | |
10 | * | |
11 | * Like the IA-64, we are a recent enough port (we are *starting* | |
12 | * with glibc2.2) that we do not need to support the old non-realtime | |
c78c2b7e | 13 | * Linux signals. Therefore we don't. |
1da177e4 LT |
14 | */ |
15 | ||
16 | #include <linux/sched.h> | |
b17b0153 | 17 | #include <linux/sched/debug.h> |
1da177e4 LT |
18 | #include <linux/mm.h> |
19 | #include <linux/smp.h> | |
1da177e4 LT |
20 | #include <linux/kernel.h> |
21 | #include <linux/signal.h> | |
22 | #include <linux/errno.h> | |
23 | #include <linux/wait.h> | |
24 | #include <linux/ptrace.h> | |
ecf02de5 | 25 | #include <linux/tracehook.h> |
1da177e4 LT |
26 | #include <linux/unistd.h> |
27 | #include <linux/stddef.h> | |
28 | #include <linux/compat.h> | |
29 | #include <linux/elf.h> | |
1da177e4 LT |
30 | #include <asm/ucontext.h> |
31 | #include <asm/rt_sigframe.h> | |
7c0f6ba6 | 32 | #include <linux/uaccess.h> |
1da177e4 LT |
33 | #include <asm/pgalloc.h> |
34 | #include <asm/cacheflush.h> | |
0013a854 | 35 | #include <asm/asm-offsets.h> |
1da177e4 LT |
36 | |
37 | #ifdef CONFIG_COMPAT | |
1da177e4 LT |
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 | ||
1da177e4 LT |
52 | /* gcc will complain if a pointer is cast to an integer of different |
53 | * size. If you really need to do this (and we do for an ELF32 user | |
54 | * application in an ELF64 kernel) then you have to do a cast to an | |
55 | * integer of the same size first. The A() macro accomplishes | |
56 | * this. */ | |
57 | #define A(__x) ((unsigned long)(__x)) | |
58 | ||
1da177e4 LT |
59 | /* |
60 | * Do a signal return - restore sigcontext. | |
61 | */ | |
62 | ||
63 | /* Trampoline for calling rt_sigreturn() */ | |
64 | #define INSN_LDI_R25_0 0x34190000 /* ldi 0,%r25 (in_syscall=0) */ | |
65 | #define INSN_LDI_R25_1 0x34190002 /* ldi 1,%r25 (in_syscall=1) */ | |
66 | #define INSN_LDI_R20 0x3414015a /* ldi __NR_rt_sigreturn,%r20 */ | |
67 | #define INSN_BLE_SR2_R0 0xe4008200 /* be,l 0x100(%sr2,%r0),%sr0,%r31 */ | |
68 | #define INSN_NOP 0x08000240 /* nop */ | |
69 | /* For debugging */ | |
70 | #define INSN_DIE_HORRIBLY 0x68000ccc /* stw %r0,0x666(%sr0,%r0) */ | |
71 | ||
72 | static long | |
73 | restore_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs) | |
74 | { | |
75 | long err = 0; | |
76 | ||
77 | err |= __copy_from_user(regs->gr, sc->sc_gr, sizeof(regs->gr)); | |
78 | err |= __copy_from_user(regs->fr, sc->sc_fr, sizeof(regs->fr)); | |
79 | err |= __copy_from_user(regs->iaoq, sc->sc_iaoq, sizeof(regs->iaoq)); | |
80 | err |= __copy_from_user(regs->iasq, sc->sc_iasq, sizeof(regs->iasq)); | |
81 | err |= __get_user(regs->sar, &sc->sc_sar); | |
8e33a52f | 82 | DBG(2,"restore_sigcontext: iaoq is %#lx / %#lx\n", |
1da177e4 LT |
83 | regs->iaoq[0],regs->iaoq[1]); |
84 | DBG(2,"restore_sigcontext: r28 is %ld\n", regs->gr[28]); | |
85 | return err; | |
86 | } | |
87 | ||
88 | void | |
89 | sys_rt_sigreturn(struct pt_regs *regs, int in_syscall) | |
90 | { | |
91 | struct rt_sigframe __user *frame; | |
1da177e4 LT |
92 | sigset_t set; |
93 | unsigned long usp = (regs->gr[30] & ~(0x01UL)); | |
94 | unsigned long sigframe_size = PARISC_RT_SIGFRAME_SIZE; | |
a8f44e38 | 95 | #ifdef CONFIG_64BIT |
1da177e4 LT |
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 | ||
f56141e3 | 102 | current->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 | 115 | DBG(2,"sys_rt_sigreturn: ELF32 process.\n"); |
d74f0f47 | 116 | if (get_compat_sigset(&set, &compat_frame->uc.uc_sigmask)) |
1da177e4 | 117 | goto give_sigsegv; |
1da177e4 LT |
118 | } else |
119 | #endif | |
120 | { | |
121 | if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set))) | |
122 | goto give_sigsegv; | |
123 | } | |
124 | ||
ade7728b | 125 | set_current_blocked(&set); |
1da177e4 LT |
126 | |
127 | /* Good thing we saved the old gr[30], eh? */ | |
a8f44e38 | 128 | #ifdef CONFIG_64BIT |
a3ea84fa | 129 | if (is_compat_task()) { |
1da177e4 LT |
130 | DBG(1,"sys_rt_sigreturn: compat_frame->uc.uc_mcontext 0x%p\n", |
131 | &compat_frame->uc.uc_mcontext); | |
132 | // FIXME: Load upper half from register file | |
133 | if (restore_sigcontext32(&compat_frame->uc.uc_mcontext, | |
134 | &compat_frame->regs, regs)) | |
135 | goto give_sigsegv; | |
136 | DBG(1,"sys_rt_sigreturn: usp %#08lx stack 0x%p\n", | |
137 | usp, &compat_frame->uc.uc_stack); | |
6e26aab9 | 138 | if (compat_restore_altstack(&compat_frame->uc.uc_stack)) |
1da177e4 LT |
139 | goto give_sigsegv; |
140 | } else | |
141 | #endif | |
142 | { | |
143 | DBG(1,"sys_rt_sigreturn: frame->uc.uc_mcontext 0x%p\n", | |
144 | &frame->uc.uc_mcontext); | |
145 | if (restore_sigcontext(&frame->uc.uc_mcontext, regs)) | |
146 | goto give_sigsegv; | |
147 | DBG(1,"sys_rt_sigreturn: usp %#08lx stack 0x%p\n", | |
148 | usp, &frame->uc.uc_stack); | |
6e26aab9 | 149 | if (restore_altstack(&frame->uc.uc_stack)) |
1da177e4 LT |
150 | goto give_sigsegv; |
151 | } | |
152 | ||
153 | ||
154 | ||
155 | /* If we are on the syscall path IAOQ will not be restored, and | |
156 | * if we are on the interrupt path we must not corrupt gr31. | |
157 | */ | |
158 | if (in_syscall) | |
159 | regs->gr[31] = regs->iaoq[0]; | |
160 | #if DEBUG_SIG | |
161 | DBG(1,"sys_rt_sigreturn: returning to %#lx, DUMPING REGS:\n", regs->iaoq[0]); | |
162 | show_regs(regs); | |
163 | #endif | |
164 | return; | |
165 | ||
166 | give_sigsegv: | |
167 | DBG(1,"sys_rt_sigreturn: Sending SIGSEGV\n"); | |
67bace72 | 168 | force_sig(SIGSEGV, current); |
1da177e4 LT |
169 | return; |
170 | } | |
171 | ||
172 | /* | |
173 | * Set up a signal frame. | |
174 | */ | |
175 | ||
176 | static inline void __user * | |
177 | get_sigframe(struct k_sigaction *ka, unsigned long sp, size_t frame_size) | |
178 | { | |
179 | /*FIXME: ELF32 vs. ELF64 has different frame_size, but since we | |
180 | don't use the parameter it doesn't matter */ | |
181 | ||
182 | DBG(1,"get_sigframe: ka = %#lx, sp = %#lx, frame_size = %#lx\n", | |
183 | (unsigned long)ka, sp, frame_size); | |
184 | ||
ad30f3ff JDA |
185 | /* Align alternate stack and reserve 64 bytes for the signal |
186 | handler's frame marker. */ | |
d09042da | 187 | if ((ka->sa.sa_flags & SA_ONSTACK) != 0 && ! sas_ss_flags(sp)) |
ad30f3ff | 188 | sp = (current->sas_ss_sp + 0x7f) & ~0x3f; /* Stacks grow up! */ |
1da177e4 LT |
189 | |
190 | DBG(1,"get_sigframe: Returning sp = %#lx\n", (unsigned long)sp); | |
191 | return (void __user *) sp; /* Stacks grow up. Fun. */ | |
192 | } | |
193 | ||
194 | static long | |
195 | setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs, int in_syscall) | |
196 | ||
197 | { | |
198 | unsigned long flags = 0; | |
199 | long err = 0; | |
200 | ||
201 | if (on_sig_stack((unsigned long) sc)) | |
202 | flags |= PARISC_SC_FLAG_ONSTACK; | |
203 | if (in_syscall) { | |
204 | flags |= PARISC_SC_FLAG_IN_SYSCALL; | |
205 | /* regs->iaoq is undefined in the syscall return path */ | |
206 | err |= __put_user(regs->gr[31], &sc->sc_iaoq[0]); | |
207 | err |= __put_user(regs->gr[31]+4, &sc->sc_iaoq[1]); | |
208 | err |= __put_user(regs->sr[3], &sc->sc_iasq[0]); | |
209 | err |= __put_user(regs->sr[3], &sc->sc_iasq[1]); | |
210 | DBG(1,"setup_sigcontext: iaoq %#lx / %#lx (in syscall)\n", | |
211 | regs->gr[31], regs->gr[31]+4); | |
212 | } else { | |
213 | err |= __copy_to_user(sc->sc_iaoq, regs->iaoq, sizeof(regs->iaoq)); | |
214 | err |= __copy_to_user(sc->sc_iasq, regs->iasq, sizeof(regs->iasq)); | |
215 | DBG(1,"setup_sigcontext: iaoq %#lx / %#lx (not in syscall)\n", | |
216 | regs->iaoq[0], regs->iaoq[1]); | |
217 | } | |
218 | ||
219 | err |= __put_user(flags, &sc->sc_flags); | |
220 | err |= __copy_to_user(sc->sc_gr, regs->gr, sizeof(regs->gr)); | |
221 | err |= __copy_to_user(sc->sc_fr, regs->fr, sizeof(regs->fr)); | |
222 | err |= __put_user(regs->sar, &sc->sc_sar); | |
223 | DBG(1,"setup_sigcontext: r28 is %ld\n", regs->gr[28]); | |
224 | ||
225 | return err; | |
226 | } | |
227 | ||
228 | static long | |
e4dc894b RW |
229 | setup_rt_frame(struct ksignal *ksig, sigset_t *set, struct pt_regs *regs, |
230 | int in_syscall) | |
1da177e4 LT |
231 | { |
232 | struct rt_sigframe __user *frame; | |
233 | unsigned long rp, usp; | |
234 | unsigned long haddr, sigframe_size; | |
ef470a60 | 235 | unsigned long start, end; |
1da177e4 | 236 | int err = 0; |
a8f44e38 | 237 | #ifdef CONFIG_64BIT |
1da177e4 | 238 | struct compat_rt_sigframe __user * compat_frame; |
1da177e4 LT |
239 | #endif |
240 | ||
241 | usp = (regs->gr[30] & ~(0x01UL)); | |
242 | /*FIXME: frame_size parameter is unused, remove it. */ | |
e4dc894b | 243 | frame = get_sigframe(&ksig->ka, usp, sizeof(*frame)); |
1da177e4 LT |
244 | |
245 | DBG(1,"SETUP_RT_FRAME: START\n"); | |
e4dc894b | 246 | DBG(1,"setup_rt_frame: frame %p info %p\n", frame, ksig->info); |
1da177e4 LT |
247 | |
248 | ||
a8f44e38 | 249 | #ifdef CONFIG_64BIT |
1da177e4 LT |
250 | |
251 | compat_frame = (struct compat_rt_sigframe __user *)frame; | |
252 | ||
a3ea84fa | 253 | if (is_compat_task()) { |
1da177e4 | 254 | DBG(1,"setup_rt_frame: frame->info = 0x%p\n", &compat_frame->info); |
e4dc894b | 255 | err |= copy_siginfo_to_user32(&compat_frame->info, &ksig->info); |
6e26aab9 | 256 | err |= __compat_save_altstack( &compat_frame->uc.uc_stack, regs->gr[30]); |
1da177e4 LT |
257 | DBG(1,"setup_rt_frame: frame->uc = 0x%p\n", &compat_frame->uc); |
258 | DBG(1,"setup_rt_frame: frame->uc.uc_mcontext = 0x%p\n", &compat_frame->uc.uc_mcontext); | |
259 | err |= setup_sigcontext32(&compat_frame->uc.uc_mcontext, | |
260 | &compat_frame->regs, regs, in_syscall); | |
d74f0f47 AV |
261 | err |= put_compat_sigset(&compat_frame->uc.uc_sigmask, set, |
262 | sizeof(compat_sigset_t)); | |
1da177e4 LT |
263 | } else |
264 | #endif | |
265 | { | |
266 | DBG(1,"setup_rt_frame: frame->info = 0x%p\n", &frame->info); | |
e4dc894b | 267 | err |= copy_siginfo_to_user(&frame->info, &ksig->info); |
6e26aab9 | 268 | err |= __save_altstack(&frame->uc.uc_stack, regs->gr[30]); |
1da177e4 LT |
269 | DBG(1,"setup_rt_frame: frame->uc = 0x%p\n", &frame->uc); |
270 | DBG(1,"setup_rt_frame: frame->uc.uc_mcontext = 0x%p\n", &frame->uc.uc_mcontext); | |
271 | err |= setup_sigcontext(&frame->uc.uc_mcontext, regs, in_syscall); | |
25985edc | 272 | /* FIXME: Should probably be converted as well for the compat case */ |
1da177e4 LT |
273 | err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set)); |
274 | } | |
275 | ||
276 | if (err) | |
e4dc894b | 277 | return -EFAULT; |
1da177e4 LT |
278 | |
279 | /* Set up to return from userspace. If provided, use a stub | |
280 | already in userspace. The first words of tramp are used to | |
281 | save the previous sigrestartblock trampoline that might be | |
282 | on the stack. We start the sigreturn trampoline at | |
283 | SIGRESTARTBLOCK_TRAMP+X. */ | |
284 | err |= __put_user(in_syscall ? INSN_LDI_R25_1 : INSN_LDI_R25_0, | |
285 | &frame->tramp[SIGRESTARTBLOCK_TRAMP+0]); | |
286 | err |= __put_user(INSN_LDI_R20, | |
287 | &frame->tramp[SIGRESTARTBLOCK_TRAMP+1]); | |
288 | err |= __put_user(INSN_BLE_SR2_R0, | |
289 | &frame->tramp[SIGRESTARTBLOCK_TRAMP+2]); | |
290 | err |= __put_user(INSN_NOP, &frame->tramp[SIGRESTARTBLOCK_TRAMP+3]); | |
291 | ||
292 | #if DEBUG_SIG | |
293 | /* Assert that we're flushing in the correct space... */ | |
294 | { | |
45b6eff2 | 295 | unsigned long sid; |
1da177e4 LT |
296 | asm ("mfsp %%sr3,%0" : "=r" (sid)); |
297 | DBG(1,"setup_rt_frame: Flushing 64 bytes at space %#x offset %p\n", | |
298 | sid, frame->tramp); | |
299 | } | |
300 | #endif | |
301 | ||
ef470a60 JDA |
302 | start = (unsigned long) &frame->tramp[0]; |
303 | end = (unsigned long) &frame->tramp[TRAMP_SIZE]; | |
304 | flush_user_dcache_range_asm(start, end); | |
305 | flush_user_icache_range_asm(start, end); | |
1da177e4 | 306 | |
efad798b | 307 | /* TRAMP Words 0-4, Length 5 = SIGRESTARTBLOCK_TRAMP |
1da177e4 LT |
308 | * TRAMP Words 5-9, Length 4 = SIGRETURN_TRAMP |
309 | * So the SIGRETURN_TRAMP is at the end of SIGRESTARTBLOCK_TRAMP | |
310 | */ | |
311 | rp = (unsigned long) &frame->tramp[SIGRESTARTBLOCK_TRAMP]; | |
312 | ||
313 | if (err) | |
e4dc894b | 314 | return -EFAULT; |
1da177e4 | 315 | |
e4dc894b | 316 | haddr = A(ksig->ka.sa.sa_handler); |
1da177e4 | 317 | /* The sa_handler may be a pointer to a function descriptor */ |
a8f44e38 | 318 | #ifdef CONFIG_64BIT |
a3ea84fa | 319 | if (is_compat_task()) { |
1da177e4 LT |
320 | #endif |
321 | if (haddr & PA_PLABEL_FDESC) { | |
322 | Elf32_Fdesc fdesc; | |
323 | Elf32_Fdesc __user *ufdesc = (Elf32_Fdesc __user *)A(haddr & ~3); | |
324 | ||
325 | err = __copy_from_user(&fdesc, ufdesc, sizeof(fdesc)); | |
326 | ||
327 | if (err) | |
e4dc894b | 328 | return -EFAULT; |
1da177e4 LT |
329 | |
330 | haddr = fdesc.addr; | |
331 | regs->gr[19] = fdesc.gp; | |
332 | } | |
a8f44e38 | 333 | #ifdef CONFIG_64BIT |
1da177e4 LT |
334 | } else { |
335 | Elf64_Fdesc fdesc; | |
336 | Elf64_Fdesc __user *ufdesc = (Elf64_Fdesc __user *)A(haddr & ~3); | |
337 | ||
338 | err = __copy_from_user(&fdesc, ufdesc, sizeof(fdesc)); | |
339 | ||
340 | if (err) | |
e4dc894b | 341 | return -EFAULT; |
1da177e4 LT |
342 | |
343 | haddr = fdesc.addr; | |
344 | regs->gr[19] = fdesc.gp; | |
345 | DBG(1,"setup_rt_frame: 64 bit signal, exe=%#lx, r19=%#lx, in_syscall=%d\n", | |
346 | haddr, regs->gr[19], in_syscall); | |
347 | } | |
348 | #endif | |
349 | ||
350 | /* The syscall return path will create IAOQ values from r31. | |
351 | */ | |
352 | sigframe_size = PARISC_RT_SIGFRAME_SIZE; | |
a8f44e38 | 353 | #ifdef CONFIG_64BIT |
a3ea84fa | 354 | if (is_compat_task()) |
1da177e4 LT |
355 | sigframe_size = PARISC_RT_SIGFRAME_SIZE32; |
356 | #endif | |
357 | if (in_syscall) { | |
358 | regs->gr[31] = haddr; | |
a8f44e38 | 359 | #ifdef CONFIG_64BIT |
df570b9c | 360 | if (!test_thread_flag(TIF_32BIT)) |
1da177e4 LT |
361 | sigframe_size |= 1; |
362 | #endif | |
363 | } else { | |
364 | unsigned long psw = USER_PSW; | |
a8f44e38 | 365 | #ifdef CONFIG_64BIT |
df570b9c | 366 | if (!test_thread_flag(TIF_32BIT)) |
1da177e4 LT |
367 | psw |= PSW_W; |
368 | #endif | |
369 | ||
370 | /* If we are singlestepping, arrange a trap to be delivered | |
371 | when we return to userspace. Note the semantics -- we | |
372 | should trap before the first insn in the handler is | |
373 | executed. Ref: | |
374 | http://sources.redhat.com/ml/gdb/2004-11/msg00245.html | |
375 | */ | |
376 | if (pa_psw(current)->r) { | |
377 | pa_psw(current)->r = 0; | |
378 | psw |= PSW_R; | |
379 | mtctl(-1, 0); | |
380 | } | |
381 | ||
382 | regs->gr[0] = psw; | |
383 | regs->iaoq[0] = haddr | 3; | |
384 | regs->iaoq[1] = regs->iaoq[0] + 4; | |
385 | } | |
386 | ||
387 | regs->gr[2] = rp; /* userland return pointer */ | |
e4dc894b | 388 | regs->gr[26] = ksig->sig; /* signal number */ |
1da177e4 | 389 | |
a8f44e38 | 390 | #ifdef CONFIG_64BIT |
a3ea84fa | 391 | if (is_compat_task()) { |
1da177e4 LT |
392 | regs->gr[25] = A(&compat_frame->info); /* siginfo pointer */ |
393 | regs->gr[24] = A(&compat_frame->uc); /* ucontext pointer */ | |
394 | } else | |
395 | #endif | |
396 | { | |
397 | regs->gr[25] = A(&frame->info); /* siginfo pointer */ | |
398 | regs->gr[24] = A(&frame->uc); /* ucontext pointer */ | |
399 | } | |
400 | ||
401 | DBG(1,"setup_rt_frame: making sigreturn frame: %#lx + %#lx = %#lx\n", | |
402 | regs->gr[30], sigframe_size, | |
403 | regs->gr[30] + sigframe_size); | |
404 | /* Raise the user stack pointer to make a proper call frame. */ | |
405 | regs->gr[30] = (A(frame) + sigframe_size); | |
406 | ||
407 | ||
408 | DBG(1,"setup_rt_frame: sig deliver (%s,%d) frame=0x%p sp=%#lx iaoq=%#lx/%#lx rp=%#lx\n", | |
409 | current->comm, current->pid, frame, regs->gr[30], | |
410 | regs->iaoq[0], regs->iaoq[1], rp); | |
411 | ||
1da177e4 LT |
412 | return 0; |
413 | } | |
414 | ||
415 | /* | |
416 | * OK, we're invoking a handler. | |
417 | */ | |
418 | ||
e3b880c6 | 419 | static void |
e4dc894b | 420 | handle_signal(struct ksignal *ksig, struct pt_regs *regs, int in_syscall) |
1da177e4 | 421 | { |
e4dc894b | 422 | int ret; |
b7f9a11a | 423 | sigset_t *oldset = sigmask_to_save(); |
e4dc894b | 424 | |
1da177e4 | 425 | DBG(1,"handle_signal: sig=%ld, ka=%p, info=%p, oldset=%p, regs=%p\n", |
e4dc894b | 426 | ksig->sig, ksig->ka, ksig->info, oldset, regs); |
1da177e4 LT |
427 | |
428 | /* Set up the stack frame */ | |
e4dc894b | 429 | ret = setup_rt_frame(ksig, oldset, regs, in_syscall); |
1da177e4 | 430 | |
e4dc894b RW |
431 | signal_setup_done(ret, ksig, test_thread_flag(TIF_SINGLESTEP) || |
432 | test_thread_flag(TIF_BLOCKSTEP)); | |
ecf02de5 | 433 | |
a610d6e6 AV |
434 | DBG(1,KERN_DEBUG "do_signal: Exit (success), regs->gr[28] = %ld\n", |
435 | regs->gr[28]); | |
1da177e4 LT |
436 | } |
437 | ||
71a71fb5 HD |
438 | /* |
439 | * Check how the syscall number gets loaded into %r20 within | |
440 | * the delay branch in userspace and adjust as needed. | |
441 | */ | |
442 | ||
443 | static void check_syscallno_in_delay_branch(struct pt_regs *regs) | |
444 | { | |
445 | u32 opcode, source_reg; | |
446 | u32 __user *uaddr; | |
447 | int err; | |
448 | ||
449 | /* Usually we don't have to restore %r20 (the system call number) | |
450 | * because it gets loaded in the delay slot of the branch external | |
451 | * instruction via the ldi instruction. | |
452 | * In some cases a register-to-register copy instruction might have | |
453 | * been used instead, in which case we need to copy the syscall | |
454 | * number into the source register before returning to userspace. | |
455 | */ | |
456 | ||
457 | /* A syscall is just a branch, so all we have to do is fiddle the | |
458 | * return pointer so that the ble instruction gets executed again. | |
459 | */ | |
460 | regs->gr[31] -= 8; /* delayed branching */ | |
461 | ||
462 | /* Get assembler opcode of code in delay branch */ | |
463 | uaddr = (unsigned int *) ((regs->gr[31] & ~3) + 4); | |
464 | err = get_user(opcode, uaddr); | |
465 | if (err) | |
466 | return; | |
467 | ||
468 | /* Check if delay branch uses "ldi int,%r20" */ | |
469 | if ((opcode & 0xffff0000) == 0x34140000) | |
470 | return; /* everything ok, just return */ | |
471 | ||
472 | /* Check if delay branch uses "nop" */ | |
473 | if (opcode == INSN_NOP) | |
474 | return; | |
475 | ||
476 | /* Check if delay branch uses "copy %rX,%r20" */ | |
477 | if ((opcode & 0xffe0ffff) == 0x08000254) { | |
478 | source_reg = (opcode >> 16) & 31; | |
479 | regs->gr[source_reg] = regs->gr[20]; | |
480 | return; | |
481 | } | |
482 | ||
483 | pr_warn("syscall restart: %s (pid %d): unexpected opcode 0x%08x\n", | |
484 | current->comm, task_pid_nr(current), opcode); | |
485 | } | |
486 | ||
2b163b71 KM |
487 | static inline void |
488 | syscall_restart(struct pt_regs *regs, struct k_sigaction *ka) | |
489 | { | |
00df111e AV |
490 | if (regs->orig_r28) |
491 | return; | |
492 | regs->orig_r28 = 1; /* no more restarts */ | |
2b163b71 KM |
493 | /* Check the return code */ |
494 | switch (regs->gr[28]) { | |
495 | case -ERESTART_RESTARTBLOCK: | |
2b163b71 KM |
496 | case -ERESTARTNOHAND: |
497 | DBG(1,"ERESTARTNOHAND: returning -EINTR\n"); | |
498 | regs->gr[28] = -EINTR; | |
499 | break; | |
500 | ||
501 | case -ERESTARTSYS: | |
502 | if (!(ka->sa.sa_flags & SA_RESTART)) { | |
503 | DBG(1,"ERESTARTSYS: putting -EINTR\n"); | |
504 | regs->gr[28] = -EINTR; | |
505 | break; | |
506 | } | |
507 | /* fallthrough */ | |
508 | case -ERESTARTNOINTR: | |
71a71fb5 | 509 | check_syscallno_in_delay_branch(regs); |
2b163b71 KM |
510 | break; |
511 | } | |
512 | } | |
513 | ||
514 | static inline void | |
515 | insert_restart_trampoline(struct pt_regs *regs) | |
516 | { | |
00df111e AV |
517 | if (regs->orig_r28) |
518 | return; | |
519 | regs->orig_r28 = 1; /* no more restarts */ | |
2b163b71 KM |
520 | switch(regs->gr[28]) { |
521 | case -ERESTART_RESTARTBLOCK: { | |
522 | /* Restart the system call - no handlers present */ | |
523 | unsigned int *usp = (unsigned int *)regs->gr[30]; | |
0bd1e94b HD |
524 | unsigned long start = (unsigned long) &usp[2]; |
525 | unsigned long end = (unsigned long) &usp[5]; | |
526 | long err = 0; | |
2b163b71 KM |
527 | |
528 | /* Setup a trampoline to restart the syscall | |
529 | * with __NR_restart_syscall | |
530 | * | |
531 | * 0: <return address (orig r31)> | |
532 | * 4: <2nd half for 64-bit> | |
533 | * 8: ldw 0(%sp), %r31 | |
534 | * 12: be 0x100(%sr2, %r0) | |
535 | * 16: ldi __NR_restart_syscall, %r20 | |
536 | */ | |
537 | #ifdef CONFIG_64BIT | |
0bd1e94b HD |
538 | err |= put_user(regs->gr[31] >> 32, &usp[0]); |
539 | err |= put_user(regs->gr[31] & 0xffffffff, &usp[1]); | |
540 | err |= put_user(0x0fc010df, &usp[2]); | |
2b163b71 | 541 | #else |
0bd1e94b HD |
542 | err |= put_user(regs->gr[31], &usp[0]); |
543 | err |= put_user(0x0fc0109f, &usp[2]); | |
2b163b71 | 544 | #endif |
0bd1e94b HD |
545 | err |= put_user(0xe0008200, &usp[3]); |
546 | err |= put_user(0x34140000, &usp[4]); | |
2b163b71 | 547 | |
0bd1e94b HD |
548 | WARN_ON(err); |
549 | ||
550 | /* flush data/instruction cache for new insns */ | |
ef470a60 JDA |
551 | flush_user_dcache_range_asm(start, end); |
552 | flush_user_icache_range_asm(start, end); | |
2b163b71 KM |
553 | |
554 | regs->gr[31] = regs->gr[30] + 8; | |
2b163b71 KM |
555 | return; |
556 | } | |
557 | case -ERESTARTNOHAND: | |
558 | case -ERESTARTSYS: | |
71a71fb5 HD |
559 | case -ERESTARTNOINTR: |
560 | check_syscallno_in_delay_branch(regs); | |
2b163b71 | 561 | return; |
2b163b71 KM |
562 | default: |
563 | break; | |
564 | } | |
565 | } | |
566 | ||
1da177e4 LT |
567 | /* |
568 | * Note that 'init' is a special process: it doesn't get signals it doesn't | |
569 | * want to handle. Thus you cannot kill init even with a SIGKILL even by | |
570 | * mistake. | |
571 | * | |
572 | * We need to be able to restore the syscall arguments (r21-r26) to | |
573 | * restart syscalls. Thus, the syscall path should save them in the | |
574 | * pt_regs structure (it's okay to do so since they are caller-save | |
575 | * registers). As noted below, the syscall number gets restored for | |
576 | * us due to the magic of delayed branching. | |
577 | */ | |
4650f0a5 KM |
578 | asmlinkage void |
579 | do_signal(struct pt_regs *regs, long in_syscall) | |
1da177e4 | 580 | { |
e4dc894b | 581 | struct ksignal ksig; |
1da177e4 | 582 | |
b7f9a11a AV |
583 | DBG(1,"\ndo_signal: regs=0x%p, sr7 %#lx, in_syscall=%d\n", |
584 | regs, regs->sr[7], in_syscall); | |
1da177e4 | 585 | |
e4dc894b RW |
586 | if (get_signal(&ksig)) { |
587 | DBG(3,"do_signal: signr = %d, regs->gr[28] = %ld\n", signr, regs->gr[28]); | |
1da177e4 | 588 | /* Restart a system call if necessary. */ |
2b163b71 | 589 | if (in_syscall) |
e4dc894b | 590 | syscall_restart(regs, &ksig.ka); |
2b163b71 | 591 | |
e4dc894b | 592 | handle_signal(&ksig, regs, in_syscall); |
e3b880c6 | 593 | return; |
1da177e4 | 594 | } |
1da177e4 LT |
595 | |
596 | /* Did we come from a system call? */ | |
2b163b71 KM |
597 | if (in_syscall) |
598 | insert_restart_trampoline(regs); | |
1da177e4 LT |
599 | |
600 | DBG(1,"do_signal: Exit (not delivered), regs->gr[28] = %ld\n", | |
601 | regs->gr[28]); | |
602 | ||
51a7b448 | 603 | restore_saved_sigmask(); |
4650f0a5 KM |
604 | } |
605 | ||
606 | void do_notify_resume(struct pt_regs *regs, long in_syscall) | |
607 | { | |
6fd84c08 | 608 | if (test_thread_flag(TIF_SIGPENDING)) |
4650f0a5 | 609 | do_signal(regs, in_syscall); |
d0420c83 DH |
610 | |
611 | if (test_thread_flag(TIF_NOTIFY_RESUME)) { | |
612 | clear_thread_flag(TIF_NOTIFY_RESUME); | |
613 | tracehook_notify_resume(regs); | |
614 | } | |
1da177e4 | 615 | } |