| /* |
| * Copyright 2004-2010 Analog Devices Inc. |
| * |
| * Licensed under the GPL-2 or later |
| */ |
| |
| #include <linux/signal.h> |
| #include <linux/syscalls.h> |
| #include <linux/ptrace.h> |
| #include <linux/tty.h> |
| #include <linux/personality.h> |
| #include <linux/binfmts.h> |
| #include <linux/freezer.h> |
| #include <linux/uaccess.h> |
| #include <linux/tracehook.h> |
| |
| #include <asm/cacheflush.h> |
| #include <asm/ucontext.h> |
| #include <asm/fixed_code.h> |
| #include <asm/syscall.h> |
| |
| #define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP))) |
| |
| /* Location of the trace bit in SYSCFG. */ |
| #define TRACE_BITS 0x0001 |
| |
| struct fdpic_func_descriptor { |
| unsigned long text; |
| unsigned long GOT; |
| }; |
| |
| struct rt_sigframe { |
| int sig; |
| struct siginfo *pinfo; |
| void *puc; |
| /* This is no longer needed by the kernel, but unfortunately userspace |
| * code expects it to be there. */ |
| char retcode[8]; |
| struct siginfo info; |
| struct ucontext uc; |
| }; |
| |
| asmlinkage int sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss) |
| { |
| return do_sigaltstack(uss, uoss, rdusp()); |
| } |
| |
| static inline int |
| rt_restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc, int *pr0) |
| { |
| unsigned long usp = 0; |
| int err = 0; |
| |
| /* Always make any pending restarted system calls return -EINTR */ |
| current_thread_info()->restart_block.fn = do_no_restart_syscall; |
| |
| #define RESTORE(x) err |= __get_user(regs->x, &sc->sc_##x) |
| |
| /* restore passed registers */ |
| RESTORE(r0); RESTORE(r1); RESTORE(r2); RESTORE(r3); |
| RESTORE(r4); RESTORE(r5); RESTORE(r6); RESTORE(r7); |
| RESTORE(p0); RESTORE(p1); RESTORE(p2); RESTORE(p3); |
| RESTORE(p4); RESTORE(p5); |
| err |= __get_user(usp, &sc->sc_usp); |
| wrusp(usp); |
| RESTORE(a0w); RESTORE(a1w); |
| RESTORE(a0x); RESTORE(a1x); |
| RESTORE(astat); |
| RESTORE(rets); |
| RESTORE(pc); |
| RESTORE(retx); |
| RESTORE(fp); |
| RESTORE(i0); RESTORE(i1); RESTORE(i2); RESTORE(i3); |
| RESTORE(m0); RESTORE(m1); RESTORE(m2); RESTORE(m3); |
| RESTORE(l0); RESTORE(l1); RESTORE(l2); RESTORE(l3); |
| RESTORE(b0); RESTORE(b1); RESTORE(b2); RESTORE(b3); |
| RESTORE(lc0); RESTORE(lc1); |
| RESTORE(lt0); RESTORE(lt1); |
| RESTORE(lb0); RESTORE(lb1); |
| RESTORE(seqstat); |
| |
| regs->orig_p0 = -1; /* disable syscall checks */ |
| |
| *pr0 = regs->r0; |
| return err; |
| } |
| |
| asmlinkage int do_rt_sigreturn(unsigned long __unused) |
| { |
| struct pt_regs *regs = (struct pt_regs *)__unused; |
| unsigned long usp = rdusp(); |
| struct rt_sigframe *frame = (struct rt_sigframe *)(usp); |
| sigset_t set; |
| int r0; |
| |
| if (!access_ok(VERIFY_READ, frame, sizeof(*frame))) |
| goto badframe; |
| if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set))) |
| goto badframe; |
| |
| sigdelsetmask(&set, ~_BLOCKABLE); |
| spin_lock_irq(¤t->sighand->siglock); |
| current->blocked = set; |
| recalc_sigpending(); |
| spin_unlock_irq(¤t->sighand->siglock); |
| |
| if (rt_restore_sigcontext(regs, &frame->uc.uc_mcontext, &r0)) |
| goto badframe; |
| |
| if (do_sigaltstack(&frame->uc.uc_stack, NULL, regs->usp) == -EFAULT) |
| goto badframe; |
| |
| return r0; |
| |
| badframe: |
| force_sig(SIGSEGV, current); |
| return 0; |
| } |
| |
| static inline int rt_setup_sigcontext(struct sigcontext *sc, struct pt_regs *regs) |
| { |
| int err = 0; |
| |
| #define SETUP(x) err |= __put_user(regs->x, &sc->sc_##x) |
| |
| SETUP(r0); SETUP(r1); SETUP(r2); SETUP(r3); |
| SETUP(r4); SETUP(r5); SETUP(r6); SETUP(r7); |
| SETUP(p0); SETUP(p1); SETUP(p2); SETUP(p3); |
| SETUP(p4); SETUP(p5); |
| err |= __put_user(rdusp(), &sc->sc_usp); |
| SETUP(a0w); SETUP(a1w); |
| SETUP(a0x); SETUP(a1x); |
| SETUP(astat); |
| SETUP(rets); |
| SETUP(pc); |
| SETUP(retx); |
| SETUP(fp); |
| SETUP(i0); SETUP(i1); SETUP(i2); SETUP(i3); |
| SETUP(m0); SETUP(m1); SETUP(m2); SETUP(m3); |
| SETUP(l0); SETUP(l1); SETUP(l2); SETUP(l3); |
| SETUP(b0); SETUP(b1); SETUP(b2); SETUP(b3); |
| SETUP(lc0); SETUP(lc1); |
| SETUP(lt0); SETUP(lt1); |
| SETUP(lb0); SETUP(lb1); |
| SETUP(seqstat); |
| |
| return err; |
| } |
| |
| static inline void *get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, |
| size_t frame_size) |
| { |
| unsigned long usp; |
| |
| /* Default to using normal stack. */ |
| usp = rdusp(); |
| |
| /* This is the X/Open sanctioned signal stack switching. */ |
| if (ka->sa.sa_flags & SA_ONSTACK) { |
| if (!on_sig_stack(usp)) |
| usp = current->sas_ss_sp + current->sas_ss_size; |
| } |
| return (void *)((usp - frame_size) & -8UL); |
| } |
| |
| static int |
| setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t * info, |
| sigset_t * set, struct pt_regs *regs) |
| { |
| struct rt_sigframe *frame; |
| int err = 0; |
| |
| frame = get_sigframe(ka, regs, sizeof(*frame)); |
| |
| err |= __put_user((current_thread_info()->exec_domain |
| && current_thread_info()->exec_domain->signal_invmap |
| && sig < 32 |
| ? current_thread_info()->exec_domain-> |
| signal_invmap[sig] : sig), &frame->sig); |
| |
| err |= __put_user(&frame->info, &frame->pinfo); |
| err |= __put_user(&frame->uc, &frame->puc); |
| err |= copy_siginfo_to_user(&frame->info, info); |
| |
| /* Create the ucontext. */ |
| err |= __put_user(0, &frame->uc.uc_flags); |
| err |= __put_user(0, &frame->uc.uc_link); |
| err |= |
| __put_user((void *)current->sas_ss_sp, &frame->uc.uc_stack.ss_sp); |
| err |= __put_user(sas_ss_flags(rdusp()), &frame->uc.uc_stack.ss_flags); |
| err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size); |
| err |= rt_setup_sigcontext(&frame->uc.uc_mcontext, regs); |
| err |= copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set)); |
| |
| if (err) |
| goto give_sigsegv; |
| |
| /* Set up registers for signal handler */ |
| wrusp((unsigned long)frame); |
| if (current->personality & FDPIC_FUNCPTRS) { |
| struct fdpic_func_descriptor __user *funcptr = |
| (struct fdpic_func_descriptor *) ka->sa.sa_handler; |
| __get_user(regs->pc, &funcptr->text); |
| __get_user(regs->p3, &funcptr->GOT); |
| } else |
| regs->pc = (unsigned long)ka->sa.sa_handler; |
| regs->rets = SIGRETURN_STUB; |
| |
| regs->r0 = frame->sig; |
| regs->r1 = (unsigned long)(&frame->info); |
| regs->r2 = (unsigned long)(&frame->uc); |
| |
| return 0; |
| |
| give_sigsegv: |
| if (sig == SIGSEGV) |
| ka->sa.sa_handler = SIG_DFL; |
| force_sig(SIGSEGV, current); |
| return -EFAULT; |
| } |
| |
| static inline void |
| handle_restart(struct pt_regs *regs, struct k_sigaction *ka, int has_handler) |
| { |
| switch (regs->r0) { |
| case -ERESTARTNOHAND: |
| if (!has_handler) |
| goto do_restart; |
| regs->r0 = -EINTR; |
| break; |
| |
| case -ERESTARTSYS: |
| if (has_handler && !(ka->sa.sa_flags & SA_RESTART)) { |
| regs->r0 = -EINTR; |
| break; |
| } |
| /* fallthrough */ |
| case -ERESTARTNOINTR: |
| do_restart: |
| regs->p0 = regs->orig_p0; |
| regs->r0 = regs->orig_r0; |
| regs->pc -= 2; |
| break; |
| |
| case -ERESTART_RESTARTBLOCK: |
| regs->p0 = __NR_restart_syscall; |
| regs->pc -= 2; |
| break; |
| } |
| } |
| |
| /* |
| * OK, we're invoking a handler |
| */ |
| static int |
| handle_signal(int sig, siginfo_t *info, struct k_sigaction *ka, |
| sigset_t *oldset, struct pt_regs *regs) |
| { |
| int ret; |
| |
| /* are we from a system call? to see pt_regs->orig_p0 */ |
| if (regs->orig_p0 >= 0) |
| /* If so, check system call restarting.. */ |
| handle_restart(regs, ka, 1); |
| |
| /* set up the stack frame */ |
| ret = setup_rt_frame(sig, ka, info, oldset, regs); |
| |
| if (ret == 0) { |
| spin_lock_irq(¤t->sighand->siglock); |
| sigorsets(¤t->blocked, ¤t->blocked, |
| &ka->sa.sa_mask); |
| if (!(ka->sa.sa_flags & SA_NODEFER)) |
| sigaddset(¤t->blocked, sig); |
| recalc_sigpending(); |
| spin_unlock_irq(¤t->sighand->siglock); |
| } |
| return ret; |
| } |
| |
| /* |
| * Note that 'init' is a special process: it doesn't get signals it doesn't |
| * want to handle. Thus you cannot kill init even with a SIGKILL even by |
| * mistake. |
| * |
| * Note that we go through the signals twice: once to check the signals |
| * that the kernel can handle, and then we build all the user-level signal |
| * handling stack-frames in one go after that. |
| */ |
| asmlinkage void do_signal(struct pt_regs *regs) |
| { |
| siginfo_t info; |
| int signr; |
| struct k_sigaction ka; |
| sigset_t *oldset; |
| |
| current->thread.esp0 = (unsigned long)regs; |
| |
| if (try_to_freeze()) |
| goto no_signal; |
| |
| if (test_thread_flag(TIF_RESTORE_SIGMASK)) |
| oldset = ¤t->saved_sigmask; |
| else |
| oldset = ¤t->blocked; |
| |
| signr = get_signal_to_deliver(&info, &ka, regs, NULL); |
| if (signr > 0) { |
| /* Whee! Actually deliver the signal. */ |
| if (handle_signal(signr, &info, &ka, oldset, regs) == 0) { |
| /* a signal was successfully delivered; the saved |
| * sigmask will have been stored in the signal frame, |
| * and will be restored by sigreturn, so we can simply |
| * clear the TIF_RESTORE_SIGMASK flag */ |
| if (test_thread_flag(TIF_RESTORE_SIGMASK)) |
| clear_thread_flag(TIF_RESTORE_SIGMASK); |
| |
| tracehook_signal_handler(signr, &info, &ka, regs, |
| test_thread_flag(TIF_SINGLESTEP)); |
| } |
| |
| return; |
| } |
| |
| no_signal: |
| /* Did we come from a system call? */ |
| if (regs->orig_p0 >= 0) |
| /* Restart the system call - no handlers present */ |
| handle_restart(regs, NULL, 0); |
| |
| /* if there's no signal to deliver, we just put the saved sigmask |
| * back */ |
| if (test_thread_flag(TIF_RESTORE_SIGMASK)) { |
| clear_thread_flag(TIF_RESTORE_SIGMASK); |
| sigprocmask(SIG_SETMASK, ¤t->saved_sigmask, NULL); |
| } |
| } |
| |
| /* |
| * notification of userspace execution resumption |
| */ |
| asmlinkage void do_notify_resume(struct pt_regs *regs) |
| { |
| if (test_thread_flag(TIF_SIGPENDING) || test_thread_flag(TIF_RESTORE_SIGMASK)) |
| do_signal(regs); |
| |
| if (test_thread_flag(TIF_NOTIFY_RESUME)) { |
| clear_thread_flag(TIF_NOTIFY_RESUME); |
| tracehook_notify_resume(regs); |
| if (current->replacement_session_keyring) |
| key_replace_session_keyring(); |
| } |
| } |
| |