diff options
Diffstat (limited to 'arch/blackfin/kernel/signal.c')
| -rw-r--r-- | arch/blackfin/kernel/signal.c | 354 |
1 files changed, 354 insertions, 0 deletions
diff --git a/arch/blackfin/kernel/signal.c b/arch/blackfin/kernel/signal.c new file mode 100644 index 00000000..d536f35d --- /dev/null +++ b/arch/blackfin/kernel/signal.c @@ -0,0 +1,354 @@ +/* + * 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(); + } +} + |