2 * Copyright 2004-2010 Analog Devices Inc.
4 * Licensed under the GPL-2 or later
7 #include <linux/signal.h>
8 #include <linux/syscalls.h>
9 #include <linux/ptrace.h>
10 #include <linux/tty.h>
11 #include <linux/personality.h>
12 #include <linux/binfmts.h>
13 #include <linux/freezer.h>
14 #include <linux/uaccess.h>
15 #include <linux/tracehook.h>
17 #include <asm/cacheflush.h>
18 #include <asm/ucontext.h>
19 #include <asm/fixed_code.h>
20 #include <asm/syscall.h>
22 /* Location of the trace bit in SYSCFG. */
23 #define TRACE_BITS 0x0001
25 struct fdpic_func_descriptor {
32 struct siginfo *pinfo;
34 /* This is no longer needed by the kernel, but unfortunately userspace
35 * code expects it to be there. */
41 asmlinkage int sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss)
43 return do_sigaltstack(uss, uoss, rdusp());
47 rt_restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc, int *pr0)
49 unsigned long usp = 0;
52 /* Always make any pending restarted system calls return -EINTR */
53 current_thread_info()->restart_block.fn = do_no_restart_syscall;
55 #define RESTORE(x) err |= __get_user(regs->x, &sc->sc_##x)
57 /* restore passed registers */
58 RESTORE(r0); RESTORE(r1); RESTORE(r2); RESTORE(r3);
59 RESTORE(r4); RESTORE(r5); RESTORE(r6); RESTORE(r7);
60 RESTORE(p0); RESTORE(p1); RESTORE(p2); RESTORE(p3);
61 RESTORE(p4); RESTORE(p5);
62 err |= __get_user(usp, &sc->sc_usp);
64 RESTORE(a0w); RESTORE(a1w);
65 RESTORE(a0x); RESTORE(a1x);
71 RESTORE(i0); RESTORE(i1); RESTORE(i2); RESTORE(i3);
72 RESTORE(m0); RESTORE(m1); RESTORE(m2); RESTORE(m3);
73 RESTORE(l0); RESTORE(l1); RESTORE(l2); RESTORE(l3);
74 RESTORE(b0); RESTORE(b1); RESTORE(b2); RESTORE(b3);
75 RESTORE(lc0); RESTORE(lc1);
76 RESTORE(lt0); RESTORE(lt1);
77 RESTORE(lb0); RESTORE(lb1);
80 regs->orig_p0 = -1; /* disable syscall checks */
86 asmlinkage int do_rt_sigreturn(unsigned long __unused)
88 struct pt_regs *regs = (struct pt_regs *)__unused;
89 unsigned long usp = rdusp();
90 struct rt_sigframe *frame = (struct rt_sigframe *)(usp);
94 if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
96 if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
99 set_current_blocked(&set);
101 if (rt_restore_sigcontext(regs, &frame->uc.uc_mcontext, &r0))
104 if (do_sigaltstack(&frame->uc.uc_stack, NULL, regs->usp) == -EFAULT)
110 force_sig(SIGSEGV, current);
114 static inline int rt_setup_sigcontext(struct sigcontext *sc, struct pt_regs *regs)
118 #define SETUP(x) err |= __put_user(regs->x, &sc->sc_##x)
120 SETUP(r0); SETUP(r1); SETUP(r2); SETUP(r3);
121 SETUP(r4); SETUP(r5); SETUP(r6); SETUP(r7);
122 SETUP(p0); SETUP(p1); SETUP(p2); SETUP(p3);
123 SETUP(p4); SETUP(p5);
124 err |= __put_user(rdusp(), &sc->sc_usp);
125 SETUP(a0w); SETUP(a1w);
126 SETUP(a0x); SETUP(a1x);
132 SETUP(i0); SETUP(i1); SETUP(i2); SETUP(i3);
133 SETUP(m0); SETUP(m1); SETUP(m2); SETUP(m3);
134 SETUP(l0); SETUP(l1); SETUP(l2); SETUP(l3);
135 SETUP(b0); SETUP(b1); SETUP(b2); SETUP(b3);
136 SETUP(lc0); SETUP(lc1);
137 SETUP(lt0); SETUP(lt1);
138 SETUP(lb0); SETUP(lb1);
144 static inline void *get_sigframe(struct k_sigaction *ka, struct pt_regs *regs,
149 /* Default to using normal stack. */
152 /* This is the X/Open sanctioned signal stack switching. */
153 if (ka->sa.sa_flags & SA_ONSTACK) {
154 if (!on_sig_stack(usp))
155 usp = current->sas_ss_sp + current->sas_ss_size;
157 return (void *)((usp - frame_size) & -8UL);
161 setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t * info,
162 sigset_t * set, struct pt_regs *regs)
164 struct rt_sigframe *frame;
167 frame = get_sigframe(ka, regs, sizeof(*frame));
169 err |= __put_user((current_thread_info()->exec_domain
170 && current_thread_info()->exec_domain->signal_invmap
172 ? current_thread_info()->exec_domain->
173 signal_invmap[sig] : sig), &frame->sig);
175 err |= __put_user(&frame->info, &frame->pinfo);
176 err |= __put_user(&frame->uc, &frame->puc);
177 err |= copy_siginfo_to_user(&frame->info, info);
179 /* Create the ucontext. */
180 err |= __put_user(0, &frame->uc.uc_flags);
181 err |= __put_user(0, &frame->uc.uc_link);
183 __put_user((void *)current->sas_ss_sp, &frame->uc.uc_stack.ss_sp);
184 err |= __put_user(sas_ss_flags(rdusp()), &frame->uc.uc_stack.ss_flags);
185 err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
186 err |= rt_setup_sigcontext(&frame->uc.uc_mcontext, regs);
187 err |= copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
192 /* Set up registers for signal handler */
193 if (current->personality & FDPIC_FUNCPTRS) {
194 struct fdpic_func_descriptor __user *funcptr =
195 (struct fdpic_func_descriptor *) ka->sa.sa_handler;
197 err |= __get_user(pc, &funcptr->text);
198 err |= __get_user(p3, &funcptr->GOT);
204 regs->pc = (unsigned long)ka->sa.sa_handler;
205 wrusp((unsigned long)frame);
206 regs->rets = SIGRETURN_STUB;
208 regs->r0 = frame->sig;
209 regs->r1 = (unsigned long)(&frame->info);
210 regs->r2 = (unsigned long)(&frame->uc);
216 handle_restart(struct pt_regs *regs, struct k_sigaction *ka, int has_handler)
219 case -ERESTARTNOHAND:
226 if (has_handler && !(ka->sa.sa_flags & SA_RESTART)) {
231 case -ERESTARTNOINTR:
233 regs->p0 = regs->orig_p0;
234 regs->r0 = regs->orig_r0;
238 case -ERESTART_RESTARTBLOCK:
239 regs->p0 = __NR_restart_syscall;
246 * OK, we're invoking a handler
249 handle_signal(int sig, siginfo_t *info, struct k_sigaction *ka,
250 struct pt_regs *regs)
252 /* are we from a system call? to see pt_regs->orig_p0 */
253 if (regs->orig_p0 >= 0)
254 /* If so, check system call restarting.. */
255 handle_restart(regs, ka, 1);
257 /* set up the stack frame */
258 if (setup_rt_frame(sig, ka, info, sigmask_to_save(), regs) < 0)
259 force_sigsegv(sig, current);
261 signal_delivered(sig, info, ka, regs,
262 test_thread_flag(TIF_SINGLESTEP));
266 * Note that 'init' is a special process: it doesn't get signals it doesn't
267 * want to handle. Thus you cannot kill init even with a SIGKILL even by
270 * Note that we go through the signals twice: once to check the signals
271 * that the kernel can handle, and then we build all the user-level signal
272 * handling stack-frames in one go after that.
274 asmlinkage void do_signal(struct pt_regs *regs)
278 struct k_sigaction ka;
280 current->thread.esp0 = (unsigned long)regs;
282 signr = get_signal_to_deliver(&info, &ka, regs, NULL);
284 /* Whee! Actually deliver the signal. */
285 handle_signal(signr, &info, &ka, regs);
289 /* Did we come from a system call? */
290 if (regs->orig_p0 >= 0)
291 /* Restart the system call - no handlers present */
292 handle_restart(regs, NULL, 0);
294 /* if there's no signal to deliver, we just put the saved sigmask
296 restore_saved_sigmask();
300 * notification of userspace execution resumption
302 asmlinkage void do_notify_resume(struct pt_regs *regs)
304 if (test_thread_flag(TIF_SIGPENDING))
307 if (test_thread_flag(TIF_NOTIFY_RESUME)) {
308 clear_thread_flag(TIF_NOTIFY_RESUME);
309 tracehook_notify_resume(regs);