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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 | 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 */ | |
1da177e4 LT |
67 | /* For debugging */ |
68 | #define INSN_DIE_HORRIBLY 0x68000ccc /* stw %r0,0x666(%sr0,%r0) */ | |
69 | ||
70 | static long | |
71 | restore_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs) | |
72 | { | |
73 | long err = 0; | |
74 | ||
75 | err |= __copy_from_user(regs->gr, sc->sc_gr, sizeof(regs->gr)); | |
76 | err |= __copy_from_user(regs->fr, sc->sc_fr, sizeof(regs->fr)); | |
77 | err |= __copy_from_user(regs->iaoq, sc->sc_iaoq, sizeof(regs->iaoq)); | |
78 | err |= __copy_from_user(regs->iasq, sc->sc_iasq, sizeof(regs->iasq)); | |
79 | err |= __get_user(regs->sar, &sc->sc_sar); | |
8e33a52f | 80 | DBG(2,"restore_sigcontext: iaoq is %#lx / %#lx\n", |
1da177e4 LT |
81 | regs->iaoq[0],regs->iaoq[1]); |
82 | DBG(2,"restore_sigcontext: r28 is %ld\n", regs->gr[28]); | |
83 | return err; | |
84 | } | |
85 | ||
86 | void | |
87 | sys_rt_sigreturn(struct pt_regs *regs, int in_syscall) | |
88 | { | |
89 | struct rt_sigframe __user *frame; | |
1da177e4 LT |
90 | sigset_t set; |
91 | unsigned long usp = (regs->gr[30] & ~(0x01UL)); | |
92 | unsigned long sigframe_size = PARISC_RT_SIGFRAME_SIZE; | |
a8f44e38 | 93 | #ifdef CONFIG_64BIT |
1da177e4 LT |
94 | struct compat_rt_sigframe __user * compat_frame; |
95 | ||
a3ea84fa | 96 | if (is_compat_task()) |
1da177e4 LT |
97 | sigframe_size = PARISC_RT_SIGFRAME_SIZE32; |
98 | #endif | |
99 | ||
f56141e3 | 100 | current->restart_block.fn = do_no_restart_syscall; |
1da177e4 LT |
101 | |
102 | /* Unwind the user stack to get the rt_sigframe structure. */ | |
103 | frame = (struct rt_sigframe __user *) | |
104 | (usp - sigframe_size); | |
105 | DBG(2,"sys_rt_sigreturn: frame is %p\n", frame); | |
106 | ||
00df111e AV |
107 | regs->orig_r28 = 1; /* no restarts for sigreturn */ |
108 | ||
a8f44e38 | 109 | #ifdef CONFIG_64BIT |
1da177e4 LT |
110 | compat_frame = (struct compat_rt_sigframe __user *)frame; |
111 | ||
a3ea84fa | 112 | if (is_compat_task()) { |
1da177e4 | 113 | DBG(2,"sys_rt_sigreturn: ELF32 process.\n"); |
d74f0f47 | 114 | if (get_compat_sigset(&set, &compat_frame->uc.uc_sigmask)) |
1da177e4 | 115 | goto give_sigsegv; |
1da177e4 LT |
116 | } else |
117 | #endif | |
118 | { | |
119 | if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set))) | |
120 | goto give_sigsegv; | |
121 | } | |
122 | ||
ade7728b | 123 | set_current_blocked(&set); |
1da177e4 LT |
124 | |
125 | /* Good thing we saved the old gr[30], eh? */ | |
a8f44e38 | 126 | #ifdef CONFIG_64BIT |
a3ea84fa | 127 | if (is_compat_task()) { |
1da177e4 LT |
128 | DBG(1,"sys_rt_sigreturn: compat_frame->uc.uc_mcontext 0x%p\n", |
129 | &compat_frame->uc.uc_mcontext); | |
130 | // FIXME: Load upper half from register file | |
131 | if (restore_sigcontext32(&compat_frame->uc.uc_mcontext, | |
132 | &compat_frame->regs, regs)) | |
133 | goto give_sigsegv; | |
134 | DBG(1,"sys_rt_sigreturn: usp %#08lx stack 0x%p\n", | |
135 | usp, &compat_frame->uc.uc_stack); | |
6e26aab9 | 136 | if (compat_restore_altstack(&compat_frame->uc.uc_stack)) |
1da177e4 LT |
137 | goto give_sigsegv; |
138 | } else | |
139 | #endif | |
140 | { | |
141 | DBG(1,"sys_rt_sigreturn: frame->uc.uc_mcontext 0x%p\n", | |
142 | &frame->uc.uc_mcontext); | |
143 | if (restore_sigcontext(&frame->uc.uc_mcontext, regs)) | |
144 | goto give_sigsegv; | |
145 | DBG(1,"sys_rt_sigreturn: usp %#08lx stack 0x%p\n", | |
146 | usp, &frame->uc.uc_stack); | |
6e26aab9 | 147 | if (restore_altstack(&frame->uc.uc_stack)) |
1da177e4 LT |
148 | goto give_sigsegv; |
149 | } | |
150 | ||
151 | ||
152 | ||
153 | /* If we are on the syscall path IAOQ will not be restored, and | |
154 | * if we are on the interrupt path we must not corrupt gr31. | |
155 | */ | |
156 | if (in_syscall) | |
157 | regs->gr[31] = regs->iaoq[0]; | |
158 | #if DEBUG_SIG | |
159 | DBG(1,"sys_rt_sigreturn: returning to %#lx, DUMPING REGS:\n", regs->iaoq[0]); | |
160 | show_regs(regs); | |
161 | #endif | |
162 | return; | |
163 | ||
164 | give_sigsegv: | |
165 | DBG(1,"sys_rt_sigreturn: Sending SIGSEGV\n"); | |
3cf5d076 | 166 | force_sig(SIGSEGV); |
1da177e4 LT |
167 | return; |
168 | } | |
169 | ||
170 | /* | |
171 | * Set up a signal frame. | |
172 | */ | |
173 | ||
174 | static inline void __user * | |
175 | get_sigframe(struct k_sigaction *ka, unsigned long sp, size_t frame_size) | |
176 | { | |
177 | /*FIXME: ELF32 vs. ELF64 has different frame_size, but since we | |
178 | don't use the parameter it doesn't matter */ | |
179 | ||
180 | DBG(1,"get_sigframe: ka = %#lx, sp = %#lx, frame_size = %#lx\n", | |
181 | (unsigned long)ka, sp, frame_size); | |
182 | ||
ad30f3ff JDA |
183 | /* Align alternate stack and reserve 64 bytes for the signal |
184 | handler's frame marker. */ | |
d09042da | 185 | if ((ka->sa.sa_flags & SA_ONSTACK) != 0 && ! sas_ss_flags(sp)) |
ad30f3ff | 186 | sp = (current->sas_ss_sp + 0x7f) & ~0x3f; /* Stacks grow up! */ |
1da177e4 LT |
187 | |
188 | DBG(1,"get_sigframe: Returning sp = %#lx\n", (unsigned long)sp); | |
189 | return (void __user *) sp; /* Stacks grow up. Fun. */ | |
190 | } | |
191 | ||
192 | static long | |
193 | setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs, int in_syscall) | |
194 | ||
195 | { | |
196 | unsigned long flags = 0; | |
197 | long err = 0; | |
198 | ||
199 | if (on_sig_stack((unsigned long) sc)) | |
200 | flags |= PARISC_SC_FLAG_ONSTACK; | |
201 | if (in_syscall) { | |
202 | flags |= PARISC_SC_FLAG_IN_SYSCALL; | |
203 | /* regs->iaoq is undefined in the syscall return path */ | |
204 | err |= __put_user(regs->gr[31], &sc->sc_iaoq[0]); | |
205 | err |= __put_user(regs->gr[31]+4, &sc->sc_iaoq[1]); | |
206 | err |= __put_user(regs->sr[3], &sc->sc_iasq[0]); | |
207 | err |= __put_user(regs->sr[3], &sc->sc_iasq[1]); | |
208 | DBG(1,"setup_sigcontext: iaoq %#lx / %#lx (in syscall)\n", | |
209 | regs->gr[31], regs->gr[31]+4); | |
210 | } else { | |
211 | err |= __copy_to_user(sc->sc_iaoq, regs->iaoq, sizeof(regs->iaoq)); | |
212 | err |= __copy_to_user(sc->sc_iasq, regs->iasq, sizeof(regs->iasq)); | |
213 | DBG(1,"setup_sigcontext: iaoq %#lx / %#lx (not in syscall)\n", | |
214 | regs->iaoq[0], regs->iaoq[1]); | |
215 | } | |
216 | ||
217 | err |= __put_user(flags, &sc->sc_flags); | |
218 | err |= __copy_to_user(sc->sc_gr, regs->gr, sizeof(regs->gr)); | |
219 | err |= __copy_to_user(sc->sc_fr, regs->fr, sizeof(regs->fr)); | |
220 | err |= __put_user(regs->sar, &sc->sc_sar); | |
221 | DBG(1,"setup_sigcontext: r28 is %ld\n", regs->gr[28]); | |
222 | ||
223 | return err; | |
224 | } | |
225 | ||
226 | static long | |
e4dc894b RW |
227 | setup_rt_frame(struct ksignal *ksig, sigset_t *set, struct pt_regs *regs, |
228 | int in_syscall) | |
1da177e4 LT |
229 | { |
230 | struct rt_sigframe __user *frame; | |
231 | unsigned long rp, usp; | |
232 | unsigned long haddr, sigframe_size; | |
ef470a60 | 233 | unsigned long start, end; |
1da177e4 | 234 | int err = 0; |
a8f44e38 | 235 | #ifdef CONFIG_64BIT |
1da177e4 | 236 | struct compat_rt_sigframe __user * compat_frame; |
1da177e4 LT |
237 | #endif |
238 | ||
239 | usp = (regs->gr[30] & ~(0x01UL)); | |
240 | /*FIXME: frame_size parameter is unused, remove it. */ | |
e4dc894b | 241 | frame = get_sigframe(&ksig->ka, usp, sizeof(*frame)); |
1da177e4 LT |
242 | |
243 | DBG(1,"SETUP_RT_FRAME: START\n"); | |
e4dc894b | 244 | DBG(1,"setup_rt_frame: frame %p info %p\n", frame, ksig->info); |
1da177e4 LT |
245 | |
246 | ||
a8f44e38 | 247 | #ifdef CONFIG_64BIT |
1da177e4 LT |
248 | |
249 | compat_frame = (struct compat_rt_sigframe __user *)frame; | |
250 | ||
a3ea84fa | 251 | if (is_compat_task()) { |
1da177e4 | 252 | DBG(1,"setup_rt_frame: frame->info = 0x%p\n", &compat_frame->info); |
e4dc894b | 253 | err |= copy_siginfo_to_user32(&compat_frame->info, &ksig->info); |
6e26aab9 | 254 | err |= __compat_save_altstack( &compat_frame->uc.uc_stack, regs->gr[30]); |
1da177e4 LT |
255 | DBG(1,"setup_rt_frame: frame->uc = 0x%p\n", &compat_frame->uc); |
256 | DBG(1,"setup_rt_frame: frame->uc.uc_mcontext = 0x%p\n", &compat_frame->uc.uc_mcontext); | |
257 | err |= setup_sigcontext32(&compat_frame->uc.uc_mcontext, | |
258 | &compat_frame->regs, regs, in_syscall); | |
d74f0f47 AV |
259 | err |= put_compat_sigset(&compat_frame->uc.uc_sigmask, set, |
260 | sizeof(compat_sigset_t)); | |
1da177e4 LT |
261 | } else |
262 | #endif | |
263 | { | |
264 | DBG(1,"setup_rt_frame: frame->info = 0x%p\n", &frame->info); | |
e4dc894b | 265 | err |= copy_siginfo_to_user(&frame->info, &ksig->info); |
6e26aab9 | 266 | err |= __save_altstack(&frame->uc.uc_stack, regs->gr[30]); |
1da177e4 LT |
267 | DBG(1,"setup_rt_frame: frame->uc = 0x%p\n", &frame->uc); |
268 | DBG(1,"setup_rt_frame: frame->uc.uc_mcontext = 0x%p\n", &frame->uc.uc_mcontext); | |
269 | err |= setup_sigcontext(&frame->uc.uc_mcontext, regs, in_syscall); | |
25985edc | 270 | /* FIXME: Should probably be converted as well for the compat case */ |
1da177e4 LT |
271 | err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set)); |
272 | } | |
273 | ||
274 | if (err) | |
e4dc894b | 275 | return -EFAULT; |
1da177e4 LT |
276 | |
277 | /* Set up to return from userspace. If provided, use a stub | |
278 | already in userspace. The first words of tramp are used to | |
279 | save the previous sigrestartblock trampoline that might be | |
280 | on the stack. We start the sigreturn trampoline at | |
281 | SIGRESTARTBLOCK_TRAMP+X. */ | |
282 | err |= __put_user(in_syscall ? INSN_LDI_R25_1 : INSN_LDI_R25_0, | |
283 | &frame->tramp[SIGRESTARTBLOCK_TRAMP+0]); | |
284 | err |= __put_user(INSN_LDI_R20, | |
285 | &frame->tramp[SIGRESTARTBLOCK_TRAMP+1]); | |
286 | err |= __put_user(INSN_BLE_SR2_R0, | |
287 | &frame->tramp[SIGRESTARTBLOCK_TRAMP+2]); | |
288 | err |= __put_user(INSN_NOP, &frame->tramp[SIGRESTARTBLOCK_TRAMP+3]); | |
289 | ||
290 | #if DEBUG_SIG | |
291 | /* Assert that we're flushing in the correct space... */ | |
292 | { | |
45b6eff2 | 293 | unsigned long sid; |
1da177e4 LT |
294 | asm ("mfsp %%sr3,%0" : "=r" (sid)); |
295 | DBG(1,"setup_rt_frame: Flushing 64 bytes at space %#x offset %p\n", | |
296 | sid, frame->tramp); | |
297 | } | |
298 | #endif | |
299 | ||
ef470a60 JDA |
300 | start = (unsigned long) &frame->tramp[0]; |
301 | end = (unsigned long) &frame->tramp[TRAMP_SIZE]; | |
302 | flush_user_dcache_range_asm(start, end); | |
303 | flush_user_icache_range_asm(start, end); | |
1da177e4 | 304 | |
efad798b | 305 | /* TRAMP Words 0-4, Length 5 = SIGRESTARTBLOCK_TRAMP |
1da177e4 LT |
306 | * TRAMP Words 5-9, Length 4 = SIGRETURN_TRAMP |
307 | * So the SIGRETURN_TRAMP is at the end of SIGRESTARTBLOCK_TRAMP | |
308 | */ | |
309 | rp = (unsigned long) &frame->tramp[SIGRESTARTBLOCK_TRAMP]; | |
310 | ||
311 | if (err) | |
e4dc894b | 312 | return -EFAULT; |
1da177e4 | 313 | |
e4dc894b | 314 | haddr = A(ksig->ka.sa.sa_handler); |
1da177e4 | 315 | /* The sa_handler may be a pointer to a function descriptor */ |
a8f44e38 | 316 | #ifdef CONFIG_64BIT |
a3ea84fa | 317 | if (is_compat_task()) { |
1da177e4 LT |
318 | #endif |
319 | if (haddr & PA_PLABEL_FDESC) { | |
320 | Elf32_Fdesc fdesc; | |
321 | Elf32_Fdesc __user *ufdesc = (Elf32_Fdesc __user *)A(haddr & ~3); | |
322 | ||
323 | err = __copy_from_user(&fdesc, ufdesc, sizeof(fdesc)); | |
324 | ||
325 | if (err) | |
e4dc894b | 326 | return -EFAULT; |
1da177e4 LT |
327 | |
328 | haddr = fdesc.addr; | |
329 | regs->gr[19] = fdesc.gp; | |
330 | } | |
a8f44e38 | 331 | #ifdef CONFIG_64BIT |
1da177e4 LT |
332 | } else { |
333 | Elf64_Fdesc fdesc; | |
334 | Elf64_Fdesc __user *ufdesc = (Elf64_Fdesc __user *)A(haddr & ~3); | |
335 | ||
336 | err = __copy_from_user(&fdesc, ufdesc, sizeof(fdesc)); | |
337 | ||
338 | if (err) | |
e4dc894b | 339 | return -EFAULT; |
1da177e4 LT |
340 | |
341 | haddr = fdesc.addr; | |
342 | regs->gr[19] = fdesc.gp; | |
343 | DBG(1,"setup_rt_frame: 64 bit signal, exe=%#lx, r19=%#lx, in_syscall=%d\n", | |
344 | haddr, regs->gr[19], in_syscall); | |
345 | } | |
346 | #endif | |
347 | ||
348 | /* The syscall return path will create IAOQ values from r31. | |
349 | */ | |
350 | sigframe_size = PARISC_RT_SIGFRAME_SIZE; | |
a8f44e38 | 351 | #ifdef CONFIG_64BIT |
a3ea84fa | 352 | if (is_compat_task()) |
1da177e4 LT |
353 | sigframe_size = PARISC_RT_SIGFRAME_SIZE32; |
354 | #endif | |
355 | if (in_syscall) { | |
356 | regs->gr[31] = haddr; | |
a8f44e38 | 357 | #ifdef CONFIG_64BIT |
df570b9c | 358 | if (!test_thread_flag(TIF_32BIT)) |
1da177e4 LT |
359 | sigframe_size |= 1; |
360 | #endif | |
361 | } else { | |
362 | unsigned long psw = USER_PSW; | |
a8f44e38 | 363 | #ifdef CONFIG_64BIT |
df570b9c | 364 | if (!test_thread_flag(TIF_32BIT)) |
1da177e4 LT |
365 | psw |= PSW_W; |
366 | #endif | |
367 | ||
368 | /* If we are singlestepping, arrange a trap to be delivered | |
369 | when we return to userspace. Note the semantics -- we | |
370 | should trap before the first insn in the handler is | |
371 | executed. Ref: | |
372 | http://sources.redhat.com/ml/gdb/2004-11/msg00245.html | |
373 | */ | |
374 | if (pa_psw(current)->r) { | |
375 | pa_psw(current)->r = 0; | |
376 | psw |= PSW_R; | |
377 | mtctl(-1, 0); | |
378 | } | |
379 | ||
380 | regs->gr[0] = psw; | |
381 | regs->iaoq[0] = haddr | 3; | |
382 | regs->iaoq[1] = regs->iaoq[0] + 4; | |
383 | } | |
384 | ||
385 | regs->gr[2] = rp; /* userland return pointer */ | |
e4dc894b | 386 | regs->gr[26] = ksig->sig; /* signal number */ |
1da177e4 | 387 | |
a8f44e38 | 388 | #ifdef CONFIG_64BIT |
a3ea84fa | 389 | if (is_compat_task()) { |
1da177e4 LT |
390 | regs->gr[25] = A(&compat_frame->info); /* siginfo pointer */ |
391 | regs->gr[24] = A(&compat_frame->uc); /* ucontext pointer */ | |
392 | } else | |
393 | #endif | |
394 | { | |
395 | regs->gr[25] = A(&frame->info); /* siginfo pointer */ | |
396 | regs->gr[24] = A(&frame->uc); /* ucontext pointer */ | |
397 | } | |
398 | ||
399 | DBG(1,"setup_rt_frame: making sigreturn frame: %#lx + %#lx = %#lx\n", | |
400 | regs->gr[30], sigframe_size, | |
401 | regs->gr[30] + sigframe_size); | |
402 | /* Raise the user stack pointer to make a proper call frame. */ | |
403 | regs->gr[30] = (A(frame) + sigframe_size); | |
404 | ||
405 | ||
406 | DBG(1,"setup_rt_frame: sig deliver (%s,%d) frame=0x%p sp=%#lx iaoq=%#lx/%#lx rp=%#lx\n", | |
407 | current->comm, current->pid, frame, regs->gr[30], | |
408 | regs->iaoq[0], regs->iaoq[1], rp); | |
409 | ||
1da177e4 LT |
410 | return 0; |
411 | } | |
412 | ||
413 | /* | |
414 | * OK, we're invoking a handler. | |
415 | */ | |
416 | ||
e3b880c6 | 417 | static void |
e4dc894b | 418 | handle_signal(struct ksignal *ksig, struct pt_regs *regs, int in_syscall) |
1da177e4 | 419 | { |
e4dc894b | 420 | int ret; |
b7f9a11a | 421 | sigset_t *oldset = sigmask_to_save(); |
e4dc894b | 422 | |
1da177e4 | 423 | DBG(1,"handle_signal: sig=%ld, ka=%p, info=%p, oldset=%p, regs=%p\n", |
e4dc894b | 424 | ksig->sig, ksig->ka, ksig->info, oldset, regs); |
1da177e4 LT |
425 | |
426 | /* Set up the stack frame */ | |
e4dc894b | 427 | ret = setup_rt_frame(ksig, oldset, regs, in_syscall); |
1da177e4 | 428 | |
e4dc894b RW |
429 | signal_setup_done(ret, ksig, test_thread_flag(TIF_SINGLESTEP) || |
430 | test_thread_flag(TIF_BLOCKSTEP)); | |
ecf02de5 | 431 | |
a610d6e6 AV |
432 | DBG(1,KERN_DEBUG "do_signal: Exit (success), regs->gr[28] = %ld\n", |
433 | regs->gr[28]); | |
1da177e4 LT |
434 | } |
435 | ||
71a71fb5 HD |
436 | /* |
437 | * Check how the syscall number gets loaded into %r20 within | |
438 | * the delay branch in userspace and adjust as needed. | |
439 | */ | |
440 | ||
441 | static void check_syscallno_in_delay_branch(struct pt_regs *regs) | |
442 | { | |
443 | u32 opcode, source_reg; | |
444 | u32 __user *uaddr; | |
445 | int err; | |
446 | ||
447 | /* Usually we don't have to restore %r20 (the system call number) | |
448 | * because it gets loaded in the delay slot of the branch external | |
449 | * instruction via the ldi instruction. | |
450 | * In some cases a register-to-register copy instruction might have | |
451 | * been used instead, in which case we need to copy the syscall | |
452 | * number into the source register before returning to userspace. | |
453 | */ | |
454 | ||
455 | /* A syscall is just a branch, so all we have to do is fiddle the | |
456 | * return pointer so that the ble instruction gets executed again. | |
457 | */ | |
458 | regs->gr[31] -= 8; /* delayed branching */ | |
459 | ||
460 | /* Get assembler opcode of code in delay branch */ | |
461 | uaddr = (unsigned int *) ((regs->gr[31] & ~3) + 4); | |
462 | err = get_user(opcode, uaddr); | |
463 | if (err) | |
464 | return; | |
465 | ||
466 | /* Check if delay branch uses "ldi int,%r20" */ | |
467 | if ((opcode & 0xffff0000) == 0x34140000) | |
468 | return; /* everything ok, just return */ | |
469 | ||
470 | /* Check if delay branch uses "nop" */ | |
471 | if (opcode == INSN_NOP) | |
472 | return; | |
473 | ||
474 | /* Check if delay branch uses "copy %rX,%r20" */ | |
475 | if ((opcode & 0xffe0ffff) == 0x08000254) { | |
476 | source_reg = (opcode >> 16) & 31; | |
477 | regs->gr[source_reg] = regs->gr[20]; | |
478 | return; | |
479 | } | |
480 | ||
481 | pr_warn("syscall restart: %s (pid %d): unexpected opcode 0x%08x\n", | |
482 | current->comm, task_pid_nr(current), opcode); | |
483 | } | |
484 | ||
2b163b71 KM |
485 | static inline void |
486 | syscall_restart(struct pt_regs *regs, struct k_sigaction *ka) | |
487 | { | |
00df111e AV |
488 | if (regs->orig_r28) |
489 | return; | |
490 | regs->orig_r28 = 1; /* no more restarts */ | |
2b163b71 KM |
491 | /* Check the return code */ |
492 | switch (regs->gr[28]) { | |
493 | case -ERESTART_RESTARTBLOCK: | |
2b163b71 KM |
494 | case -ERESTARTNOHAND: |
495 | DBG(1,"ERESTARTNOHAND: returning -EINTR\n"); | |
496 | regs->gr[28] = -EINTR; | |
497 | break; | |
498 | ||
499 | case -ERESTARTSYS: | |
500 | if (!(ka->sa.sa_flags & SA_RESTART)) { | |
501 | DBG(1,"ERESTARTSYS: putting -EINTR\n"); | |
502 | regs->gr[28] = -EINTR; | |
503 | break; | |
504 | } | |
505 | /* fallthrough */ | |
506 | case -ERESTARTNOINTR: | |
71a71fb5 | 507 | check_syscallno_in_delay_branch(regs); |
2b163b71 KM |
508 | break; |
509 | } | |
510 | } | |
511 | ||
512 | static inline void | |
513 | insert_restart_trampoline(struct pt_regs *regs) | |
514 | { | |
00df111e AV |
515 | if (regs->orig_r28) |
516 | return; | |
517 | regs->orig_r28 = 1; /* no more restarts */ | |
2b163b71 KM |
518 | switch(regs->gr[28]) { |
519 | case -ERESTART_RESTARTBLOCK: { | |
520 | /* Restart the system call - no handlers present */ | |
521 | unsigned int *usp = (unsigned int *)regs->gr[30]; | |
0bd1e94b HD |
522 | unsigned long start = (unsigned long) &usp[2]; |
523 | unsigned long end = (unsigned long) &usp[5]; | |
524 | long err = 0; | |
2b163b71 KM |
525 | |
526 | /* Setup a trampoline to restart the syscall | |
527 | * with __NR_restart_syscall | |
528 | * | |
529 | * 0: <return address (orig r31)> | |
530 | * 4: <2nd half for 64-bit> | |
531 | * 8: ldw 0(%sp), %r31 | |
532 | * 12: be 0x100(%sr2, %r0) | |
533 | * 16: ldi __NR_restart_syscall, %r20 | |
534 | */ | |
535 | #ifdef CONFIG_64BIT | |
0bd1e94b HD |
536 | err |= put_user(regs->gr[31] >> 32, &usp[0]); |
537 | err |= put_user(regs->gr[31] & 0xffffffff, &usp[1]); | |
538 | err |= put_user(0x0fc010df, &usp[2]); | |
2b163b71 | 539 | #else |
0bd1e94b HD |
540 | err |= put_user(regs->gr[31], &usp[0]); |
541 | err |= put_user(0x0fc0109f, &usp[2]); | |
2b163b71 | 542 | #endif |
0bd1e94b HD |
543 | err |= put_user(0xe0008200, &usp[3]); |
544 | err |= put_user(0x34140000, &usp[4]); | |
2b163b71 | 545 | |
0bd1e94b HD |
546 | WARN_ON(err); |
547 | ||
548 | /* flush data/instruction cache for new insns */ | |
ef470a60 JDA |
549 | flush_user_dcache_range_asm(start, end); |
550 | flush_user_icache_range_asm(start, end); | |
2b163b71 KM |
551 | |
552 | regs->gr[31] = regs->gr[30] + 8; | |
2b163b71 KM |
553 | return; |
554 | } | |
555 | case -ERESTARTNOHAND: | |
556 | case -ERESTARTSYS: | |
71a71fb5 HD |
557 | case -ERESTARTNOINTR: |
558 | check_syscallno_in_delay_branch(regs); | |
2b163b71 | 559 | return; |
2b163b71 KM |
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 | 578 | { |
e4dc894b | 579 | struct ksignal ksig; |
1da177e4 | 580 | |
b7f9a11a AV |
581 | DBG(1,"\ndo_signal: regs=0x%p, sr7 %#lx, in_syscall=%d\n", |
582 | regs, regs->sr[7], in_syscall); | |
1da177e4 | 583 | |
e4dc894b RW |
584 | if (get_signal(&ksig)) { |
585 | DBG(3,"do_signal: signr = %d, regs->gr[28] = %ld\n", signr, regs->gr[28]); | |
1da177e4 | 586 | /* Restart a system call if necessary. */ |
2b163b71 | 587 | if (in_syscall) |
e4dc894b | 588 | syscall_restart(regs, &ksig.ka); |
2b163b71 | 589 | |
e4dc894b | 590 | handle_signal(&ksig, regs, in_syscall); |
e3b880c6 | 591 | return; |
1da177e4 | 592 | } |
1da177e4 LT |
593 | |
594 | /* Did we come from a system call? */ | |
2b163b71 KM |
595 | if (in_syscall) |
596 | insert_restart_trampoline(regs); | |
1da177e4 LT |
597 | |
598 | DBG(1,"do_signal: Exit (not delivered), regs->gr[28] = %ld\n", | |
599 | regs->gr[28]); | |
600 | ||
51a7b448 | 601 | restore_saved_sigmask(); |
4650f0a5 KM |
602 | } |
603 | ||
604 | void do_notify_resume(struct pt_regs *regs, long in_syscall) | |
605 | { | |
6fd84c08 | 606 | if (test_thread_flag(TIF_SIGPENDING)) |
4650f0a5 | 607 | do_signal(regs, in_syscall); |
d0420c83 DH |
608 | |
609 | if (test_thread_flag(TIF_NOTIFY_RESUME)) { | |
610 | clear_thread_flag(TIF_NOTIFY_RESUME); | |
611 | tracehook_notify_resume(regs); | |
612 | } | |
1da177e4 | 613 | } |