From 2148daa9c45ff4f91b5890f2a453e3130288064c Mon Sep 17 00:00:00 2001 From: Michal Simek Date: Fri, 27 Mar 2009 14:25:14 +0100 Subject: microblaze_v8: Signal support Reviewed-by: Ingo Molnar Acked-by: Stephen Neuendorffer Acked-by: John Linn Acked-by: John Williams Signed-off-by: Michal Simek --- arch/microblaze/kernel/signal.c | 538 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 538 insertions(+) create mode 100644 arch/microblaze/kernel/signal.c (limited to 'arch/microblaze/kernel') diff --git a/arch/microblaze/kernel/signal.c b/arch/microblaze/kernel/signal.c new file mode 100644 index 00000000000..ff347b98863 --- /dev/null +++ b/arch/microblaze/kernel/signal.c @@ -0,0 +1,538 @@ +/* + * Signal handling + * + * Copyright (C) 2008-2009 Michal Simek + * Copyright (C) 2008-2009 PetaLogix + * Copyright (C) 2003,2004 John Williams + * Copyright (C) 2001 NEC Corporation + * Copyright (C) 2001 Miles Bader + * Copyright (C) 1999,2000 Niibe Yutaka & Kaz Kojima + * Copyright (C) 1991,1992 Linus Torvalds + * + * 1997-11-28 Modified for POSIX.1b signals by Richard Henderson + * + * This file was was derived from the sh version, arch/sh/kernel/signal.c + * + * This file is subject to the terms and conditions of the GNU General + * Public License. See the file COPYING in the main directory of this + * archive for more details. + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP))) + +asmlinkage int do_signal(struct pt_regs *regs, sigset_t *oldset, int in_sycall); + +/* + * Atomically swap in the new signal mask, and wait for a signal. + */ +asmlinkage int +sys_sigsuspend(old_sigset_t mask, struct pt_regs *regs) +{ + sigset_t saveset; + + mask &= _BLOCKABLE; + spin_lock_irq(¤t->sighand->siglock); + saveset = current->blocked; + siginitset(¤t->blocked, mask); + recalc_sigpending(); + spin_unlock_irq(¤t->sighand->siglock); + + regs->r3 = -EINTR; + while (1) { + current->state = TASK_INTERRUPTIBLE; + schedule(); + if (do_signal(regs, &saveset, 1)) + return -EINTR; + } +} + +asmlinkage int +sys_rt_sigsuspend(sigset_t __user *unewset, size_t sigsetsize, + struct pt_regs *regs) +{ + sigset_t saveset, newset; + + /* XXX: Don't preclude handling different sized sigset_t's. */ + if (sigsetsize != sizeof(sigset_t)) + return -EINVAL; + + if (copy_from_user(&newset, unewset, sizeof(newset))) + return -EFAULT; + sigdelsetmask(&newset, ~_BLOCKABLE); + spin_lock_irq(¤t->sighand->siglock); + saveset = current->blocked; + current->blocked = newset; + recalc_sigpending(); + spin_unlock_irq(¤t->sighand->siglock); + + regs->r3 = -EINTR; + while (1) { + current->state = TASK_INTERRUPTIBLE; + schedule(); + if (do_signal(regs, &saveset, 1)) + return -EINTR; + } +} + +asmlinkage int +sys_sigaction(int sig, const struct old_sigaction *act, + struct old_sigaction *oact) +{ + struct k_sigaction new_ka, old_ka; + int ret; + + if (act) { + old_sigset_t mask; + if (!access_ok(VERIFY_READ, act, sizeof(*act)) || + __get_user(new_ka.sa.sa_handler, &act->sa_handler) || + __get_user(new_ka.sa.sa_restorer, &act->sa_restorer)) + return -EFAULT; + __get_user(new_ka.sa.sa_flags, &act->sa_flags); + __get_user(mask, &act->sa_mask); + siginitset(&new_ka.sa.sa_mask, mask); + } + + ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL); + + if (!ret && oact) { + if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)) || + __put_user(old_ka.sa.sa_handler, &oact->sa_handler) || + __put_user(old_ka.sa.sa_restorer, &oact->sa_restorer)) + return -EFAULT; + __put_user(old_ka.sa.sa_flags, &oact->sa_flags); + __put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask); + } + + return ret; +} + +asmlinkage int +sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss, + struct pt_regs *regs) +{ + return do_sigaltstack(uss, uoss, regs->r1); +} + +/* + * Do a signal return; undo the signal stack. + */ + +struct sigframe { + struct sigcontext sc; + unsigned long extramask[_NSIG_WORDS-1]; + unsigned long tramp[2]; /* signal trampoline */ +}; + +struct rt_sigframe { + struct siginfo info; + struct ucontext uc; + unsigned long tramp[2]; /* signal trampoline */ +}; + +static int +restore_sigcontext(struct pt_regs *regs, struct sigcontext *sc, int *rval_p) +{ + unsigned int err = 0; + +#define COPY(x) {err |= __get_user(regs->x, &sc->regs.x); } + COPY(r0); + COPY(r1); + COPY(r2); COPY(r3); COPY(r4); COPY(r5); + COPY(r6); COPY(r7); COPY(r8); COPY(r9); + COPY(r10); COPY(r11); COPY(r12); COPY(r13); + COPY(r14); COPY(r15); COPY(r16); COPY(r17); + COPY(r18); COPY(r19); COPY(r20); COPY(r21); + COPY(r22); COPY(r23); COPY(r24); COPY(r25); + COPY(r26); COPY(r27); COPY(r28); COPY(r29); + COPY(r30); COPY(r31); + COPY(pc); COPY(ear); COPY(esr); COPY(fsr); +#undef COPY + + *rval_p = regs->r3; + + return err; +} + +asmlinkage int sys_sigreturn(struct pt_regs *regs) +{ + struct sigframe *frame = (struct sigframe *)regs->r1; + sigset_t set; + int rval; + + if (!access_ok(VERIFY_READ, frame, sizeof(*frame))) + goto badframe; + + if (__get_user(set.sig[0], &frame->sc.oldmask) + || (_NSIG_WORDS > 1 + && __copy_from_user(&set.sig[1], &frame->extramask, + sizeof(frame->extramask)))) + goto badframe; + + sigdelsetmask(&set, ~_BLOCKABLE); + + spin_lock_irq(¤t->sighand->siglock); + current->blocked = set; + recalc_sigpending(); + spin_unlock_irq(¤t->sighand->siglock); + + if (restore_sigcontext(regs, &frame->sc, &rval)) + goto badframe; + return rval; + +badframe: + force_sig(SIGSEGV, current); + return 0; +} + +asmlinkage int sys_rt_sigreturn(struct pt_regs *regs) +{ + struct rt_sigframe *frame = (struct rt_sigframe *)regs->r1; + sigset_t set; + stack_t st; + int rval; + + 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 (restore_sigcontext(regs, &frame->uc.uc_mcontext, &rval)) + goto badframe; + + if (__copy_from_user((void *)&st, &frame->uc.uc_stack, sizeof(st))) + goto badframe; + /* It is more difficult to avoid calling this function than to + call it and ignore errors. */ + do_sigaltstack(&st, NULL, regs->r1); + + return rval; + +badframe: + force_sig(SIGSEGV, current); + return 0; +} + +/* + * Set up a signal frame. + */ + +static int +setup_sigcontext(struct sigcontext *sc, struct pt_regs *regs, + unsigned long mask) +{ + int err = 0; + +#define COPY(x) {err |= __put_user(regs->x, &sc->regs.x); } + COPY(r0); + COPY(r1); + COPY(r2); COPY(r3); COPY(r4); COPY(r5); + COPY(r6); COPY(r7); COPY(r8); COPY(r9); + COPY(r10); COPY(r11); COPY(r12); COPY(r13); + COPY(r14); COPY(r15); COPY(r16); COPY(r17); + COPY(r18); COPY(r19); COPY(r20); COPY(r21); + COPY(r22); COPY(r23); COPY(r24); COPY(r25); + COPY(r26); COPY(r27); COPY(r28); COPY(r29); + COPY(r30); COPY(r31); + COPY(pc); COPY(ear); COPY(esr); COPY(fsr); +#undef COPY + + err |= __put_user(mask, &sc->oldmask); + + return err; +} + +/* + * Determine which stack to use.. + */ +static inline void * +get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, size_t frame_size) +{ + /* Default to using normal stack */ + unsigned long sp = regs->r1; + + if ((ka->sa.sa_flags & SA_ONSTACK) != 0 && !on_sig_stack(sp)) + sp = current->sas_ss_sp + current->sas_ss_size; + + return (void *)((sp - frame_size) & -8UL); +} + +static void setup_frame(int sig, struct k_sigaction *ka, + sigset_t *set, struct pt_regs *regs) +{ + struct sigframe *frame; + int err = 0; + int signal; + + frame = get_sigframe(ka, regs, sizeof(*frame)); + + if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) + goto give_sigsegv; + + signal = current_thread_info()->exec_domain + && current_thread_info()->exec_domain->signal_invmap + && sig < 32 + ? current_thread_info()->exec_domain->signal_invmap[sig] + : sig; + + err |= setup_sigcontext(&frame->sc, regs, set->sig[0]); + + if (_NSIG_WORDS > 1) { + err |= __copy_to_user(frame->extramask, &set->sig[1], + sizeof(frame->extramask)); + } + + /* Set up to return from userspace. If provided, use a stub + already in userspace. */ + /* minus 8 is offset to cater for "rtsd r15,8" offset */ + if (ka->sa.sa_flags & SA_RESTORER) { + regs->r15 = ((unsigned long)ka->sa.sa_restorer)-8; + } else { + /* Note, these encodings are _big endian_! */ + + /* addi r12, r0, __NR_sigreturn */ + err |= __put_user(0x31800000 | __NR_sigreturn , + frame->tramp + 0); + /* brki r14, 0x8 */ + err |= __put_user(0xb9cc0008, frame->tramp + 1); + + /* Return from sighandler will jump to the tramp. + Negative 8 offset because return is rtsd r15, 8 */ + regs->r15 = ((unsigned long)frame->tramp)-8; + + __invalidate_cache_sigtramp((unsigned long)frame->tramp); + } + + if (err) + goto give_sigsegv; + + /* Set up registers for signal handler */ + regs->r1 = (unsigned long) frame; + /* Signal handler args: */ + regs->r5 = signal; /* Arg 0: signum */ + regs->r6 = (unsigned long) &frame->sc; /* arg 1: sigcontext */ + + /* Offset of 4 to handle microblaze rtid r14, 0 */ + regs->pc = (unsigned long)ka->sa.sa_handler; + + set_fs(USER_DS); + +#ifdef DEBUG_SIG + printk(KERN_INFO "SIG deliver (%s:%d): sp=%p pc=%08lx\n", + current->comm, current->pid, frame, regs->pc); +#endif + + return; + +give_sigsegv: + if (sig == SIGSEGV) + ka->sa.sa_handler = SIG_DFL; + force_sig(SIGSEGV, current); +} + +static void 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; + int signal; + + frame = get_sigframe(ka, regs, sizeof(*frame)); + + if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) + goto give_sigsegv; + + signal = current_thread_info()->exec_domain + && current_thread_info()->exec_domain->signal_invmap + && sig < 32 + ? current_thread_info()->exec_domain->signal_invmap[sig] + : sig; + + 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(regs->r1), + &frame->uc.uc_stack.ss_flags); + err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size); + err |= setup_sigcontext(&frame->uc.uc_mcontext, + regs, set->sig[0]); + err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set)); + + /* Set up to return from userspace. If provided, use a stub + already in userspace. */ + /* minus 8 is offset to cater for "rtsd r15,8" */ + if (ka->sa.sa_flags & SA_RESTORER) { + regs->r15 = ((unsigned long)ka->sa.sa_restorer)-8; + } else { + /* addi r12, r0, __NR_sigreturn */ + err |= __put_user(0x31800000 | __NR_rt_sigreturn , + frame->tramp + 0); + /* brki r14, 0x8 */ + err |= __put_user(0xb9cc0008, frame->tramp + 1); + + /* Return from sighandler will jump to the tramp. + Negative 8 offset because return is rtsd r15, 8 */ + regs->r15 = ((unsigned long)frame->tramp)-8; + + __invalidate_cache_sigtramp((unsigned long)frame->tramp); + } + + if (err) + goto give_sigsegv; + + /* Set up registers for signal handler */ + regs->r1 = (unsigned long) frame; + /* Signal handler args: */ + regs->r5 = signal; /* arg 0: signum */ + regs->r6 = (unsigned long) &frame->info; /* arg 1: siginfo */ + regs->r7 = (unsigned long) &frame->uc; /* arg2: ucontext */ + /* Offset to handle microblaze rtid r14, 0 */ + regs->pc = (unsigned long)ka->sa.sa_handler; + + set_fs(USER_DS); + +#ifdef DEBUG_SIG + printk(KERN_INFO "SIG deliver (%s:%d): sp=%p pc=%08lx\n", + current->comm, current->pid, frame, regs->pc); +#endif + + return; + +give_sigsegv: + if (sig == SIGSEGV) + ka->sa.sa_handler = SIG_DFL; + force_sig(SIGSEGV, current); +} + +/* Handle restarting system calls */ +static inline void +handle_restart(struct pt_regs *regs, struct k_sigaction *ka, int has_handler) +{ + switch (regs->r3) { + case -ERESTART_RESTARTBLOCK: + case -ERESTARTNOHAND: + if (!has_handler) + goto do_restart; + regs->r3 = -EINTR; + break; + case -ERESTARTSYS: + if (has_handler && !(ka->sa.sa_flags & SA_RESTART)) { + regs->r3 = -EINTR; + break; + } + /* fallthrough */ + case -ERESTARTNOINTR: +do_restart: + /* offset of 4 bytes to re-execute trap (brki) instruction */ + regs->pc -= 4; + break; + } +} + +/* + * OK, we're invoking a handler + */ + +static void +handle_signal(unsigned long sig, struct k_sigaction *ka, + siginfo_t *info, sigset_t *oldset, struct pt_regs *regs) +{ + /* Set up the stack frame */ + if (ka->sa.sa_flags & SA_SIGINFO) + setup_rt_frame(sig, ka, info, oldset, regs); + else + setup_frame(sig, ka, oldset, regs); + + if (ka->sa.sa_flags & SA_ONESHOT) + ka->sa.sa_handler = SIG_DFL; + + if (!(ka->sa.sa_flags & SA_NODEFER)) { + spin_lock_irq(¤t->sighand->siglock); + sigorsets(¤t->blocked, + ¤t->blocked, &ka->sa.sa_mask); + sigaddset(¤t->blocked, sig); + recalc_sigpending(); + spin_unlock_irq(¤t->sighand->siglock); + } +} + +/* + * 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. + */ +int do_signal(struct pt_regs *regs, sigset_t *oldset, int in_syscall) +{ + siginfo_t info; + int signr; + struct k_sigaction ka; +#ifdef DEBUG_SIG + printk(KERN_INFO "do signal: %p %p %d\n", regs, oldset, in_syscall); + printk(KERN_INFO "do signal2: %lx %lx %ld [%lx]\n", regs->pc, regs->r1, + regs->r12, current_thread_info()->flags); +#endif + /* + * We want the common case to go fast, which + * is why we may in certain cases get here from + * kernel mode. Just return without doing anything + * if so. + */ + if (kernel_mode(regs)) + return 1; + + if (!oldset) + oldset = ¤t->blocked; + + signr = get_signal_to_deliver(&info, &ka, regs, NULL); + if (signr > 0) { + /* Whee! Actually deliver the signal. */ + if (in_syscall) + handle_restart(regs, &ka, 1); + handle_signal(signr, &ka, &info, oldset, regs); + return 1; + } + + if (in_syscall) + handle_restart(regs, NULL, 0); + + /* Did we come from a system call? */ + return 0; +} -- cgit