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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>
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>
34#include <linux/tracehook.h>
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>
40#include <linux/syscalls.h>
41#include <asm/cacheflush.h>
42#include <asm/syscalls.h>
43
44/*
45 * Do a signal return; undo the signal stack.
46 */
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
59static int restore_sigcontext(struct pt_regs *regs,
60 struct sigcontext __user *sc, int *rval_p)
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
83asmlinkage long sys_rt_sigreturn(struct pt_regs *regs)
84{
85 struct rt_sigframe __user *frame =
86 (struct rt_sigframe __user *)(regs->r1);
87
88 sigset_t set;
89 int rval;
90
91 /* Always make any pending restarted system calls return -EINTR */
92 current->restart_block.fn = do_no_restart_syscall;
93
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
100 set_current_blocked(&set);
101
102 if (restore_sigcontext(regs, &frame->uc.uc_mcontext, &rval))
103 goto badframe;
104
105 if (restore_altstack(&frame->uc.uc_stack))
106 goto badframe;
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
120setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs,
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 */
147static inline void __user *
148get_sigframe(struct ksignal *ksig, struct pt_regs *regs, size_t frame_size)
149{
150 /* Default to using normal stack */
151 unsigned long sp = sigsp(regs->r1, ksig);
152
153 return (void __user *)((sp - frame_size) & -8UL);
154}
155
156static int setup_rt_frame(struct ksignal *ksig, sigset_t *set,
157 struct pt_regs *regs)
158{
159 struct rt_sigframe __user *frame;
160 int err = 0, sig = ksig->sig;
161 unsigned long address = 0;
162#ifdef CONFIG_MMU
163 pmd_t *pmdp;
164 pte_t *ptep;
165#endif
166
167 frame = get_sigframe(ksig, regs, sizeof(*frame));
168
169 if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
170 return -EFAULT;
171
172 if (ksig->ka.sa.sa_flags & SA_SIGINFO)
173 err |= copy_siginfo_to_user(&frame->info, &ksig->info);
174
175 /* Create the ucontext. */
176 err |= __put_user(0, &frame->uc.uc_flags);
177 err |= __put_user(NULL, &frame->uc.uc_link);
178 err |= __save_altstack(&frame->uc.uc_stack, regs->r1);
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" */
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
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 */
209 address = __virt_to_phys(address);
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
219 if (err)
220 return -EFAULT;
221
222 /* Set up registers for signal handler */
223 regs->r1 = (unsigned long) frame;
224
225 /* Signal handler args: */
226 regs->r5 = sig; /* arg 0: signum */
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 */
230 regs->pc = (unsigned long)ksig->ka.sa.sa_handler;
231
232#ifdef DEBUG_SIG
233 pr_info("SIG deliver (%s:%d): sp=%p pc=%08lx\n",
234 current->comm, current->pid, frame, regs->pc);
235#endif
236
237 return 0;
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
269static void
270handle_signal(struct ksignal *ksig, struct pt_regs *regs)
271{
272 sigset_t *oldset = sigmask_to_save();
273 int ret;
274
275 /* Set up the stack frame */
276 ret = setup_rt_frame(ksig, oldset, regs);
277
278 signal_setup_done(ret, ksig, test_thread_flag(TIF_SINGLESTEP));
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 */
290static void do_signal(struct pt_regs *regs, int in_syscall)
291{
292 struct ksignal ksig;
293
294#ifdef DEBUG_SIG
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,
297 regs->r12, current_thread_info()->flags);
298#endif
299
300 if (get_signal(&ksig)) {
301 /* Whee! Actually deliver the signal. */
302 if (in_syscall)
303 handle_restart(regs, &ksig.ka, 1);
304 handle_signal(&ksig, regs);
305 return;
306 }
307
308 if (in_syscall)
309 handle_restart(regs, NULL, 0);
310
311 /*
312 * If there's no signal to deliver, we just put the saved sigmask
313 * back.
314 */
315 restore_saved_sigmask();
316}
317
318asmlinkage void do_notify_resume(struct pt_regs *regs, int in_syscall)
319{
320 if (test_thread_flag(TIF_SIGPENDING))
321 do_signal(regs, in_syscall);
322
323 if (test_and_clear_thread_flag(TIF_NOTIFY_RESUME))
324 tracehook_notify_resume(regs);
325}
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>
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>
34#include <linux/tracehook.h>
35#include <asm/entry.h>
36#include <asm/ucontext.h>
37#include <linux/uaccess.h>
38#include <linux/syscalls.h>
39#include <asm/cacheflush.h>
40#include <asm/syscalls.h>
41
42/*
43 * Do a signal return; undo the signal stack.
44 */
45struct sigframe {
46 struct sigcontext sc;
47 unsigned long extramask[_NSIG_WORDS-1];
48 unsigned long tramp[2]; /* signal trampoline */
49};
50
51struct rt_sigframe {
52 struct siginfo info;
53 struct ucontext uc;
54 unsigned long tramp[2]; /* signal trampoline */
55};
56
57static int restore_sigcontext(struct pt_regs *regs,
58 struct sigcontext __user *sc, int *rval_p)
59{
60 unsigned int err = 0;
61
62#define COPY(x) {err |= __get_user(regs->x, &sc->regs.x); }
63 COPY(r0);
64 COPY(r1);
65 COPY(r2); COPY(r3); COPY(r4); COPY(r5);
66 COPY(r6); COPY(r7); COPY(r8); COPY(r9);
67 COPY(r10); COPY(r11); COPY(r12); COPY(r13);
68 COPY(r14); COPY(r15); COPY(r16); COPY(r17);
69 COPY(r18); COPY(r19); COPY(r20); COPY(r21);
70 COPY(r22); COPY(r23); COPY(r24); COPY(r25);
71 COPY(r26); COPY(r27); COPY(r28); COPY(r29);
72 COPY(r30); COPY(r31);
73 COPY(pc); COPY(ear); COPY(esr); COPY(fsr);
74#undef COPY
75
76 *rval_p = regs->r3;
77
78 return err;
79}
80
81asmlinkage long sys_rt_sigreturn(struct pt_regs *regs)
82{
83 struct rt_sigframe __user *frame =
84 (struct rt_sigframe __user *)(regs->r1);
85
86 sigset_t set;
87 int rval;
88
89 /* Always make any pending restarted system calls return -EINTR */
90 current->restart_block.fn = do_no_restart_syscall;
91
92 if (!access_ok(frame, sizeof(*frame)))
93 goto badframe;
94
95 if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
96 goto badframe;
97
98 set_current_blocked(&set);
99
100 if (restore_sigcontext(regs, &frame->uc.uc_mcontext, &rval))
101 goto badframe;
102
103 if (restore_altstack(&frame->uc.uc_stack))
104 goto badframe;
105
106 return rval;
107
108badframe:
109 force_sig(SIGSEGV);
110 return 0;
111}
112
113/*
114 * Set up a signal frame.
115 */
116
117static int
118setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs,
119 unsigned long mask)
120{
121 int err = 0;
122
123#define COPY(x) {err |= __put_user(regs->x, &sc->regs.x); }
124 COPY(r0);
125 COPY(r1);
126 COPY(r2); COPY(r3); COPY(r4); COPY(r5);
127 COPY(r6); COPY(r7); COPY(r8); COPY(r9);
128 COPY(r10); COPY(r11); COPY(r12); COPY(r13);
129 COPY(r14); COPY(r15); COPY(r16); COPY(r17);
130 COPY(r18); COPY(r19); COPY(r20); COPY(r21);
131 COPY(r22); COPY(r23); COPY(r24); COPY(r25);
132 COPY(r26); COPY(r27); COPY(r28); COPY(r29);
133 COPY(r30); COPY(r31);
134 COPY(pc); COPY(ear); COPY(esr); COPY(fsr);
135#undef COPY
136
137 err |= __put_user(mask, &sc->oldmask);
138
139 return err;
140}
141
142/*
143 * Determine which stack to use..
144 */
145static inline void __user *
146get_sigframe(struct ksignal *ksig, struct pt_regs *regs, size_t frame_size)
147{
148 /* Default to using normal stack */
149 unsigned long sp = sigsp(regs->r1, ksig);
150
151 return (void __user *)((sp - frame_size) & -8UL);
152}
153
154static int setup_rt_frame(struct ksignal *ksig, sigset_t *set,
155 struct pt_regs *regs)
156{
157 struct rt_sigframe __user *frame;
158 int err = 0, sig = ksig->sig;
159 unsigned long address = 0;
160 pmd_t *pmdp;
161 pte_t *ptep;
162
163 frame = get_sigframe(ksig, regs, sizeof(*frame));
164
165 if (!access_ok(frame, sizeof(*frame)))
166 return -EFAULT;
167
168 if (ksig->ka.sa.sa_flags & SA_SIGINFO)
169 err |= copy_siginfo_to_user(&frame->info, &ksig->info);
170
171 /* Create the ucontext. */
172 err |= __put_user(0, &frame->uc.uc_flags);
173 err |= __put_user(NULL, &frame->uc.uc_link);
174 err |= __save_altstack(&frame->uc.uc_stack, regs->r1);
175 err |= setup_sigcontext(&frame->uc.uc_mcontext,
176 regs, set->sig[0]);
177 err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
178
179 /* Set up to return from userspace. If provided, use a stub
180 already in userspace. */
181 /* minus 8 is offset to cater for "rtsd r15,8" */
182 /* addi r12, r0, __NR_sigreturn */
183 err |= __put_user(0x31800000 | __NR_rt_sigreturn ,
184 frame->tramp + 0);
185 /* brki r14, 0x8 */
186 err |= __put_user(0xb9cc0008, frame->tramp + 1);
187
188 /* Return from sighandler will jump to the tramp.
189 Negative 8 offset because return is rtsd r15, 8 */
190 regs->r15 = ((unsigned long)frame->tramp)-8;
191
192 address = ((unsigned long)frame->tramp);
193 pmdp = pmd_off(current->mm, address);
194
195 preempt_disable();
196 ptep = pte_offset_map(pmdp, address);
197 if (pte_present(*ptep)) {
198 address = (unsigned long) page_address(pte_page(*ptep));
199 /* MS: I need add offset in page */
200 address += ((unsigned long)frame->tramp) & ~PAGE_MASK;
201 /* MS address is virtual */
202 address = __virt_to_phys(address);
203 invalidate_icache_range(address, address + 8);
204 flush_dcache_range(address, address + 8);
205 }
206 pte_unmap(ptep);
207 preempt_enable();
208 if (err)
209 return -EFAULT;
210
211 /* Set up registers for signal handler */
212 regs->r1 = (unsigned long) frame;
213
214 /* Signal handler args: */
215 regs->r5 = sig; /* arg 0: signum */
216 regs->r6 = (unsigned long) &frame->info; /* arg 1: siginfo */
217 regs->r7 = (unsigned long) &frame->uc; /* arg2: ucontext */
218 /* Offset to handle microblaze rtid r14, 0 */
219 regs->pc = (unsigned long)ksig->ka.sa.sa_handler;
220
221#ifdef DEBUG_SIG
222 pr_info("SIG deliver (%s:%d): sp=%p pc=%08lx\n",
223 current->comm, current->pid, frame, regs->pc);
224#endif
225
226 return 0;
227}
228
229/* Handle restarting system calls */
230static inline void
231handle_restart(struct pt_regs *regs, struct k_sigaction *ka, int has_handler)
232{
233 switch (regs->r3) {
234 case -ERESTART_RESTARTBLOCK:
235 case -ERESTARTNOHAND:
236 if (!has_handler)
237 goto do_restart;
238 regs->r3 = -EINTR;
239 break;
240 case -ERESTARTSYS:
241 if (has_handler && !(ka->sa.sa_flags & SA_RESTART)) {
242 regs->r3 = -EINTR;
243 break;
244 }
245 fallthrough;
246 case -ERESTARTNOINTR:
247do_restart:
248 /* offset of 4 bytes to re-execute trap (brki) instruction */
249 regs->pc -= 4;
250 break;
251 }
252}
253
254/*
255 * OK, we're invoking a handler
256 */
257
258static void
259handle_signal(struct ksignal *ksig, struct pt_regs *regs)
260{
261 sigset_t *oldset = sigmask_to_save();
262 int ret;
263
264 /* Set up the stack frame */
265 ret = setup_rt_frame(ksig, oldset, regs);
266
267 signal_setup_done(ret, ksig, test_thread_flag(TIF_SINGLESTEP));
268}
269
270/*
271 * Note that 'init' is a special process: it doesn't get signals it doesn't
272 * want to handle. Thus you cannot kill init even with a SIGKILL even by
273 * mistake.
274 *
275 * Note that we go through the signals twice: once to check the signals that
276 * the kernel can handle, and then we build all the user-level signal handling
277 * stack-frames in one go after that.
278 */
279static void do_signal(struct pt_regs *regs, int in_syscall)
280{
281 struct ksignal ksig;
282
283#ifdef DEBUG_SIG
284 pr_info("do signal: %p %d\n", regs, in_syscall);
285 pr_info("do signal2: %lx %lx %ld [%lx]\n", regs->pc, regs->r1,
286 regs->r12, current_thread_info()->flags);
287#endif
288
289 if (get_signal(&ksig)) {
290 /* Whee! Actually deliver the signal. */
291 if (in_syscall)
292 handle_restart(regs, &ksig.ka, 1);
293 handle_signal(&ksig, regs);
294 return;
295 }
296
297 if (in_syscall)
298 handle_restart(regs, NULL, 0);
299
300 /*
301 * If there's no signal to deliver, we just put the saved sigmask
302 * back.
303 */
304 restore_saved_sigmask();
305}
306
307asmlinkage void do_notify_resume(struct pt_regs *regs, int in_syscall)
308{
309 if (test_thread_flag(TIF_SIGPENDING) ||
310 test_thread_flag(TIF_NOTIFY_SIGNAL))
311 do_signal(regs, in_syscall);
312
313 if (test_thread_flag(TIF_NOTIFY_RESUME))
314 tracehook_notify_resume(regs);
315}