Merge tag 'acpi-4.7-rc1-more' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael...
[linux-2.6-block.git] / arch / microblaze / kernel / signal.c
CommitLineData
2148daa9
MS
1/*
2 * Signal handling
3 *
4 * Copyright (C) 2008-2009 Michal Simek <monstr@monstr.eu>
5 * Copyright (C) 2008-2009 PetaLogix
6 * Copyright (C) 2003,2004 John Williams <jwilliams@itee.uq.edu.au>
7 * Copyright (C) 2001 NEC Corporation
8 * Copyright (C) 2001 Miles Bader <miles@gnu.org>
9 * Copyright (C) 1999,2000 Niibe Yutaka & Kaz Kojima
10 * Copyright (C) 1991,1992 Linus Torvalds
11 *
12 * 1997-11-28 Modified for POSIX.1b signals by Richard Henderson
13 *
14 * This file was was derived from the sh version, arch/sh/kernel/signal.c
15 *
16 * This file is subject to the terms and conditions of the GNU General
17 * Public License. See the file COPYING in the main directory of this
18 * archive for more details.
19 */
20
21#include <linux/sched.h>
22#include <linux/mm.h>
23#include <linux/smp.h>
2148daa9
MS
24#include <linux/kernel.h>
25#include <linux/signal.h>
26#include <linux/errno.h>
27#include <linux/wait.h>
28#include <linux/ptrace.h>
29#include <linux/unistd.h>
30#include <linux/stddef.h>
31#include <linux/personality.h>
32#include <linux/percpu.h>
33#include <linux/linkage.h>
969a9616 34#include <linux/tracehook.h>
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MS
35#include <asm/entry.h>
36#include <asm/ucontext.h>
37#include <linux/uaccess.h>
38#include <asm/pgtable.h>
39#include <asm/pgalloc.h>
2148daa9
MS
40#include <linux/syscalls.h>
41#include <asm/cacheflush.h>
42#include <asm/syscalls.h>
43
2148daa9
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44/*
45 * Do a signal return; undo the signal stack.
46 */
2148daa9
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47struct sigframe {
48 struct sigcontext sc;
49 unsigned long extramask[_NSIG_WORDS-1];
50 unsigned long tramp[2]; /* signal trampoline */
51};
52
53struct rt_sigframe {
54 struct siginfo info;
55 struct ucontext uc;
56 unsigned long tramp[2]; /* signal trampoline */
57};
58
353b431b
AB
59static int restore_sigcontext(struct pt_regs *regs,
60 struct sigcontext __user *sc, int *rval_p)
2148daa9
MS
61{
62 unsigned int err = 0;
63
64#define COPY(x) {err |= __get_user(regs->x, &sc->regs.x); }
65 COPY(r0);
66 COPY(r1);
67 COPY(r2); COPY(r3); COPY(r4); COPY(r5);
68 COPY(r6); COPY(r7); COPY(r8); COPY(r9);
69 COPY(r10); COPY(r11); COPY(r12); COPY(r13);
70 COPY(r14); COPY(r15); COPY(r16); COPY(r17);
71 COPY(r18); COPY(r19); COPY(r20); COPY(r21);
72 COPY(r22); COPY(r23); COPY(r24); COPY(r25);
73 COPY(r26); COPY(r27); COPY(r28); COPY(r29);
74 COPY(r30); COPY(r31);
75 COPY(pc); COPY(ear); COPY(esr); COPY(fsr);
76#undef COPY
77
78 *rval_p = regs->r3;
79
80 return err;
81}
82
3183e068 83asmlinkage long sys_rt_sigreturn(struct pt_regs *regs)
2148daa9 84{
353b431b 85 struct rt_sigframe __user *frame =
6e83557c 86 (struct rt_sigframe __user *)(regs->r1);
2921e2bd 87
2148daa9 88 sigset_t set;
2148daa9
MS
89 int rval;
90
58e4257b 91 /* Always make any pending restarted system calls return -EINTR */
f56141e3 92 current->restart_block.fn = do_no_restart_syscall;
58e4257b 93
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MS
94 if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
95 goto badframe;
96
97 if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
98 goto badframe;
99
60c59751 100 set_current_blocked(&set);
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101
102 if (restore_sigcontext(regs, &frame->uc.uc_mcontext, &rval))
103 goto badframe;
104
4a9d32d3 105 if (restore_altstack(&frame->uc.uc_stack))
353b431b 106 goto badframe;
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107
108 return rval;
109
110badframe:
111 force_sig(SIGSEGV, current);
112 return 0;
113}
114
115/*
116 * Set up a signal frame.
117 */
118
119static int
353b431b 120setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs,
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MS
121 unsigned long mask)
122{
123 int err = 0;
124
125#define COPY(x) {err |= __put_user(regs->x, &sc->regs.x); }
126 COPY(r0);
127 COPY(r1);
128 COPY(r2); COPY(r3); COPY(r4); COPY(r5);
129 COPY(r6); COPY(r7); COPY(r8); COPY(r9);
130 COPY(r10); COPY(r11); COPY(r12); COPY(r13);
131 COPY(r14); COPY(r15); COPY(r16); COPY(r17);
132 COPY(r18); COPY(r19); COPY(r20); COPY(r21);
133 COPY(r22); COPY(r23); COPY(r24); COPY(r25);
134 COPY(r26); COPY(r27); COPY(r28); COPY(r29);
135 COPY(r30); COPY(r31);
136 COPY(pc); COPY(ear); COPY(esr); COPY(fsr);
137#undef COPY
138
139 err |= __put_user(mask, &sc->oldmask);
140
141 return err;
142}
143
144/*
145 * Determine which stack to use..
146 */
353b431b 147static inline void __user *
c001cd21 148get_sigframe(struct ksignal *ksig, struct pt_regs *regs, size_t frame_size)
2148daa9
MS
149{
150 /* Default to using normal stack */
c001cd21 151 unsigned long sp = sigsp(regs->r1, ksig);
2148daa9 152
353b431b 153 return (void __user *)((sp - frame_size) & -8UL);
2148daa9
MS
154}
155
9c53c7ec
RW
156static int setup_rt_frame(struct ksignal *ksig, sigset_t *set,
157 struct pt_regs *regs)
2148daa9 158{
353b431b 159 struct rt_sigframe __user *frame;
9c53c7ec 160 int err = 0, sig = ksig->sig;
2ee2ff87
MS
161 unsigned long address = 0;
162#ifdef CONFIG_MMU
163 pmd_t *pmdp;
164 pte_t *ptep;
165#endif
2148daa9 166
c001cd21 167 frame = get_sigframe(ksig, regs, sizeof(*frame));
2148daa9
MS
168
169 if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
9c53c7ec 170 return -EFAULT;
2148daa9 171
9c53c7ec
RW
172 if (ksig->ka.sa.sa_flags & SA_SIGINFO)
173 err |= copy_siginfo_to_user(&frame->info, &ksig->info);
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MS
174
175 /* Create the ucontext. */
176 err |= __put_user(0, &frame->uc.uc_flags);
2cfedb97 177 err |= __put_user(NULL, &frame->uc.uc_link);
4a9d32d3 178 err |= __save_altstack(&frame->uc.uc_stack, regs->r1);
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179 err |= setup_sigcontext(&frame->uc.uc_mcontext,
180 regs, set->sig[0]);
181 err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
182
183 /* Set up to return from userspace. If provided, use a stub
184 already in userspace. */
185 /* minus 8 is offset to cater for "rtsd r15,8" */
3183e068
AB
186 /* addi r12, r0, __NR_sigreturn */
187 err |= __put_user(0x31800000 | __NR_rt_sigreturn ,
188 frame->tramp + 0);
189 /* brki r14, 0x8 */
190 err |= __put_user(0xb9cc0008, frame->tramp + 1);
191
192 /* Return from sighandler will jump to the tramp.
193 Negative 8 offset because return is rtsd r15, 8 */
194 regs->r15 = ((unsigned long)frame->tramp)-8;
195
2ee2ff87
MS
196 address = ((unsigned long)frame->tramp);
197#ifdef CONFIG_MMU
198 pmdp = pmd_offset(pud_offset(
199 pgd_offset(current->mm, address),
200 address), address);
201
202 preempt_disable();
203 ptep = pte_offset_map(pmdp, address);
204 if (pte_present(*ptep)) {
205 address = (unsigned long) page_address(pte_page(*ptep));
206 /* MS: I need add offset in page */
207 address += ((unsigned long)frame->tramp) & ~PAGE_MASK;
208 /* MS address is virtual */
a66a6265 209 address = __virt_to_phys(address);
2ee2ff87
MS
210 invalidate_icache_range(address, address + 8);
211 flush_dcache_range(address, address + 8);
212 }
213 pte_unmap(ptep);
214 preempt_enable();
215#else
216 flush_icache_range(address, address + 8);
217 flush_dcache_range(address, address + 8);
218#endif
2148daa9 219 if (err)
9c53c7ec 220 return -EFAULT;
2148daa9
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221
222 /* Set up registers for signal handler */
6e83557c 223 regs->r1 = (unsigned long) frame;
2921e2bd 224
2148daa9 225 /* Signal handler args: */
6140de5a 226 regs->r5 = sig; /* arg 0: signum */
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227 regs->r6 = (unsigned long) &frame->info; /* arg 1: siginfo */
228 regs->r7 = (unsigned long) &frame->uc; /* arg2: ucontext */
229 /* Offset to handle microblaze rtid r14, 0 */
9c53c7ec 230 regs->pc = (unsigned long)ksig->ka.sa.sa_handler;
2148daa9 231
2148daa9 232#ifdef DEBUG_SIG
6bd55f0b 233 pr_info("SIG deliver (%s:%d): sp=%p pc=%08lx\n",
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234 current->comm, current->pid, frame, regs->pc);
235#endif
236
bcb8c8d0 237 return 0;
2148daa9
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238}
239
240/* Handle restarting system calls */
241static inline void
242handle_restart(struct pt_regs *regs, struct k_sigaction *ka, int has_handler)
243{
244 switch (regs->r3) {
245 case -ERESTART_RESTARTBLOCK:
246 case -ERESTARTNOHAND:
247 if (!has_handler)
248 goto do_restart;
249 regs->r3 = -EINTR;
250 break;
251 case -ERESTARTSYS:
252 if (has_handler && !(ka->sa.sa_flags & SA_RESTART)) {
253 regs->r3 = -EINTR;
254 break;
255 }
256 /* fallthrough */
257 case -ERESTARTNOINTR:
258do_restart:
259 /* offset of 4 bytes to re-execute trap (brki) instruction */
260 regs->pc -= 4;
261 break;
262 }
263}
264
265/*
266 * OK, we're invoking a handler
267 */
268
a610d6e6 269static void
9c53c7ec 270handle_signal(struct ksignal *ksig, struct pt_regs *regs)
2148daa9 271{
b7f9a11a 272 sigset_t *oldset = sigmask_to_save();
bcb8c8d0
MF
273 int ret;
274
2148daa9 275 /* Set up the stack frame */
9c53c7ec 276 ret = setup_rt_frame(ksig, oldset, regs);
bcb8c8d0 277
9c53c7ec 278 signal_setup_done(ret, ksig, test_thread_flag(TIF_SINGLESTEP));
2148daa9
MS
279}
280
281/*
282 * Note that 'init' is a special process: it doesn't get signals it doesn't
283 * want to handle. Thus you cannot kill init even with a SIGKILL even by
284 * mistake.
285 *
286 * Note that we go through the signals twice: once to check the signals that
287 * the kernel can handle, and then we build all the user-level signal handling
288 * stack-frames in one go after that.
289 */
83140191 290static void do_signal(struct pt_regs *regs, int in_syscall)
2148daa9 291{
9c53c7ec
RW
292 struct ksignal ksig;
293
2148daa9 294#ifdef DEBUG_SIG
6bd55f0b
MS
295 pr_info("do signal: %p %d\n", regs, in_syscall);
296 pr_info("do signal2: %lx %lx %ld [%lx]\n", regs->pc, regs->r1,
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297 regs->r12, current_thread_info()->flags);
298#endif
2148daa9 299
9c53c7ec 300 if (get_signal(&ksig)) {
2148daa9
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301 /* Whee! Actually deliver the signal. */
302 if (in_syscall)
9c53c7ec
RW
303 handle_restart(regs, &ksig.ka, 1);
304 handle_signal(&ksig, regs);
83140191 305 return;
2148daa9
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306 }
307
308 if (in_syscall)
309 handle_restart(regs, NULL, 0);
310
3183e068
AB
311 /*
312 * If there's no signal to deliver, we just put the saved sigmask
313 * back.
314 */
51a7b448 315 restore_saved_sigmask();
2148daa9 316}
969a9616 317
4378bb69 318asmlinkage void do_notify_resume(struct pt_regs *regs, int in_syscall)
969a9616 319{
969a9616 320 if (test_thread_flag(TIF_SIGPENDING))
83140191 321 do_signal(regs, in_syscall);
969a9616 322
a42c6ded 323 if (test_and_clear_thread_flag(TIF_NOTIFY_RESUME))
969a9616 324 tracehook_notify_resume(regs);
969a9616 325}