diff options
Diffstat (limited to 'xenolinux-2.4.25-sparse/arch/xeno/kernel/signal.c')
| -rw-r--r-- | xenolinux-2.4.25-sparse/arch/xeno/kernel/signal.c | 717 |
1 files changed, 717 insertions, 0 deletions
diff --git a/xenolinux-2.4.25-sparse/arch/xeno/kernel/signal.c b/xenolinux-2.4.25-sparse/arch/xeno/kernel/signal.c new file mode 100644 index 0000000000..f646c5c0ca --- /dev/null +++ b/xenolinux-2.4.25-sparse/arch/xeno/kernel/signal.c @@ -0,0 +1,717 @@ +/* + * linux/arch/i386/kernel/signal.c + * + * Copyright (C) 1991, 1992 Linus Torvalds + * + * 1997-11-28 Modified for POSIX.1b signals by Richard Henderson + * 2000-06-20 Pentium III FXSR, SSE support by Gareth Hughes + */ + +#include <linux/sched.h> +#include <linux/mm.h> +#include <linux/smp.h> +#include <linux/smp_lock.h> +#include <linux/kernel.h> +#include <linux/signal.h> +#include <linux/errno.h> +#include <linux/wait.h> +#include <linux/ptrace.h> +#include <linux/unistd.h> +#include <linux/stddef.h> +#include <linux/tty.h> +#include <linux/personality.h> +#include <asm/ucontext.h> +#include <asm/uaccess.h> +#include <asm/i387.h> + +#define DEBUG_SIG 0 + +#define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP))) + +int FASTCALL(do_signal(struct pt_regs *regs, sigset_t *oldset)); + +int copy_siginfo_to_user(siginfo_t *to, siginfo_t *from) +{ + if (!access_ok (VERIFY_WRITE, to, sizeof(siginfo_t))) + return -EFAULT; + if (from->si_code < 0) + return __copy_to_user(to, from, sizeof(siginfo_t)); + else { + int err; + + /* If you change siginfo_t structure, please be sure + this code is fixed accordingly. + It should never copy any pad contained in the structure + to avoid security leaks, but must copy the generic + 3 ints plus the relevant union member. */ + err = __put_user(from->si_signo, &to->si_signo); + err |= __put_user(from->si_errno, &to->si_errno); + err |= __put_user((short)from->si_code, &to->si_code); + /* First 32bits of unions are always present. */ + err |= __put_user(from->si_pid, &to->si_pid); + switch (from->si_code >> 16) { + case __SI_FAULT >> 16: + break; + case __SI_CHLD >> 16: + err |= __put_user(from->si_utime, &to->si_utime); + err |= __put_user(from->si_stime, &to->si_stime); + err |= __put_user(from->si_status, &to->si_status); + default: + err |= __put_user(from->si_uid, &to->si_uid); + break; + /* case __SI_RT: This is not generated by the kernel as of now. */ + } + return err; + } +} + +/* + * Atomically swap in the new signal mask, and wait for a signal. + */ +asmlinkage int +sys_sigsuspend(int history0, int history1, old_sigset_t mask) +{ + struct pt_regs * regs = (struct pt_regs *) &history0; + sigset_t saveset; + + mask &= _BLOCKABLE; + spin_lock_irq(¤t->sigmask_lock); + saveset = current->blocked; + siginitset(¤t->blocked, mask); + recalc_sigpending(current); + spin_unlock_irq(¤t->sigmask_lock); + + regs->eax = -EINTR; + while (1) { + current->state = TASK_INTERRUPTIBLE; + schedule(); + if (do_signal(regs, &saveset)) + return -EINTR; + } +} + +asmlinkage int +sys_rt_sigsuspend(sigset_t *unewset, size_t sigsetsize) +{ + struct pt_regs * regs = (struct pt_regs *) &unewset; + 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->sigmask_lock); + saveset = current->blocked; + current->blocked = newset; + recalc_sigpending(current); + spin_unlock_irq(¤t->sigmask_lock); + + regs->eax = -EINTR; + while (1) { + current->state = TASK_INTERRUPTIBLE; + schedule(); + if (do_signal(regs, &saveset)) + 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 (verify_area(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 (verify_area(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 *uss, stack_t *uoss) +{ + struct pt_regs *regs = (struct pt_regs *) &uss; + return do_sigaltstack(uss, uoss, regs->esp); +} + + +/* + * Do a signal return; undo the signal stack. + */ + +struct sigframe +{ + char *pretcode; + int sig; + struct sigcontext sc; + struct _fpstate fpstate; + unsigned long extramask[_NSIG_WORDS-1]; + char retcode[8]; +}; + +struct rt_sigframe +{ + char *pretcode; + int sig; + struct siginfo *pinfo; + void *puc; + struct siginfo info; + struct ucontext uc; + struct _fpstate fpstate; + char retcode[8]; +}; + +static int +restore_sigcontext(struct pt_regs *regs, struct sigcontext *sc, int *peax) +{ + unsigned int err = 0; + +#define COPY(x) err |= __get_user(regs->x, &sc->x) + +#define COPY_SEG(seg) \ + { unsigned short tmp; \ + err |= __get_user(tmp, &sc->seg); \ + regs->x##seg = tmp; } + +#define COPY_SEG_STRICT(seg) \ + { unsigned short tmp; \ + err |= __get_user(tmp, &sc->seg); \ + regs->x##seg = tmp|3; } + +#define GET_SEG(seg) \ + { unsigned short tmp; \ + err |= __get_user(tmp, &sc->seg); \ + loadsegment(seg,tmp); } + + GET_SEG(gs); + GET_SEG(fs); + COPY_SEG(es); + COPY_SEG(ds); + COPY(edi); + COPY(esi); + COPY(ebp); + COPY(esp); + COPY(ebx); + COPY(edx); + COPY(ecx); + COPY(eip); + COPY_SEG_STRICT(cs); + COPY_SEG_STRICT(ss); + + { + unsigned int tmpflags; + err |= __get_user(tmpflags, &sc->eflags); + regs->eflags = (regs->eflags & ~0x40DD5) | (tmpflags & 0x40DD5); + regs->orig_eax = -1; /* disable syscall checks */ + } + + { + struct _fpstate * buf; + err |= __get_user(buf, &sc->fpstate); + if (buf) { + if (verify_area(VERIFY_READ, buf, sizeof(*buf))) + goto badframe; + err |= restore_i387(buf); + } + } + + err |= __get_user(*peax, &sc->eax); + return err; + +badframe: + return 1; +} + +asmlinkage int sys_sigreturn(unsigned long __unused) +{ + struct pt_regs *regs = (struct pt_regs *) &__unused; + struct sigframe *frame = (struct sigframe *)(regs->esp - 8); + sigset_t set; + int eax; + + if (verify_area(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->sigmask_lock); + current->blocked = set; + recalc_sigpending(current); + spin_unlock_irq(¤t->sigmask_lock); + + if (restore_sigcontext(regs, &frame->sc, &eax)) + goto badframe; + return eax; + +badframe: + force_sig(SIGSEGV, current); + return 0; +} + +asmlinkage int sys_rt_sigreturn(unsigned long __unused) +{ + struct pt_regs *regs = (struct pt_regs *) &__unused; + struct rt_sigframe *frame = (struct rt_sigframe *)(regs->esp - 4); + sigset_t set; + stack_t st; + int eax; + + if (verify_area(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->sigmask_lock); + current->blocked = set; + recalc_sigpending(current); + spin_unlock_irq(¤t->sigmask_lock); + + if (restore_sigcontext(regs, &frame->uc.uc_mcontext, &eax)) + goto badframe; + + if (__copy_from_user(&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->esp); + + return eax; + +badframe: + force_sig(SIGSEGV, current); + return 0; +} + +/* + * Set up a signal frame. + */ + +static int +setup_sigcontext(struct sigcontext *sc, struct _fpstate *fpstate, + struct pt_regs *regs, unsigned long mask) +{ + int tmp, err = 0; + + tmp = 0; + __asm__("movl %%gs,%0" : "=r"(tmp): "0"(tmp)); + err |= __put_user(tmp, (unsigned int *)&sc->gs); + __asm__("movl %%fs,%0" : "=r"(tmp): "0"(tmp)); + err |= __put_user(tmp, (unsigned int *)&sc->fs); + + err |= __put_user(regs->xes, (unsigned int *)&sc->es); + err |= __put_user(regs->xds, (unsigned int *)&sc->ds); + err |= __put_user(regs->edi, &sc->edi); + err |= __put_user(regs->esi, &sc->esi); + err |= __put_user(regs->ebp, &sc->ebp); + err |= __put_user(regs->esp, &sc->esp); + err |= __put_user(regs->ebx, &sc->ebx); + err |= __put_user(regs->edx, &sc->edx); + err |= __put_user(regs->ecx, &sc->ecx); + err |= __put_user(regs->eax, &sc->eax); + err |= __put_user(current->thread.trap_no, &sc->trapno); + err |= __put_user(current->thread.error_code, &sc->err); + err |= __put_user(regs->eip, &sc->eip); + err |= __put_user(regs->xcs, (unsigned int *)&sc->cs); + err |= __put_user(regs->eflags, &sc->eflags); + err |= __put_user(regs->esp, &sc->esp_at_signal); + err |= __put_user(regs->xss, (unsigned int *)&sc->ss); + + tmp = save_i387(fpstate); + if (tmp < 0) + err = 1; + else + err |= __put_user(tmp ? fpstate : NULL, &sc->fpstate); + + /* non-iBCS2 extensions.. */ + err |= __put_user(mask, &sc->oldmask); + err |= __put_user(current->thread.cr2, &sc->cr2); + + return err; +} + +/* + * Determine which stack to use.. + */ +static inline void * +get_sigframe(struct k_sigaction *ka, struct pt_regs * regs, size_t frame_size) +{ + unsigned long esp; + + /* Default to using normal stack */ + esp = regs->esp; + + /* This is the X/Open sanctioned signal stack switching. */ + if (ka->sa.sa_flags & SA_ONSTACK) { + if (sas_ss_flags(esp) == 0) + esp = current->sas_ss_sp + current->sas_ss_size; + } + + /* This is the legacy signal stack switching. */ + else if ((regs->xss & 0xffff) != __USER_DS && + !(ka->sa.sa_flags & SA_RESTORER) && + ka->sa.sa_restorer) { + esp = (unsigned long) ka->sa.sa_restorer; + } + + return (void *)((esp - 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; + + frame = get_sigframe(ka, regs, sizeof(*frame)); + + if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) + goto give_sigsegv; + + err |= __put_user((current->exec_domain + && current->exec_domain->signal_invmap + && sig < 32 + ? current->exec_domain->signal_invmap[sig] + : sig), + &frame->sig); + if (err) + goto give_sigsegv; + + err |= setup_sigcontext(&frame->sc, &frame->fpstate, regs, set->sig[0]); + if (err) + goto give_sigsegv; + + if (_NSIG_WORDS > 1) { + err |= __copy_to_user(frame->extramask, &set->sig[1], + sizeof(frame->extramask)); + } + if (err) + goto give_sigsegv; + + /* Set up to return from userspace. If provided, use a stub + already in userspace. */ + if (ka->sa.sa_flags & SA_RESTORER) { + err |= __put_user(ka->sa.sa_restorer, &frame->pretcode); + } else { + err |= __put_user(frame->retcode, &frame->pretcode); + /* This is popl %eax ; movl $,%eax ; int $0x80 */ + err |= __put_user(0xb858, (short *)(frame->retcode+0)); + err |= __put_user(__NR_sigreturn, (int *)(frame->retcode+2)); + err |= __put_user(0x80cd, (short *)(frame->retcode+6)); + } + + if (err) + goto give_sigsegv; + + /* Set up registers for signal handler */ + regs->esp = (unsigned long) frame; + regs->eip = (unsigned long) ka->sa.sa_handler; + + set_fs(USER_DS); + regs->xds = __USER_DS; + regs->xes = __USER_DS; + regs->xss = __USER_DS; + regs->xcs = __USER_CS; + regs->eflags &= ~TF_MASK; + +#if DEBUG_SIG + printk("SIG deliver (%s:%d): sp=%p pc=%p ra=%p\n", + current->comm, current->pid, frame, regs->eip, frame->pretcode); +#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; + + frame = get_sigframe(ka, regs, sizeof(*frame)); + + if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) + goto give_sigsegv; + + err |= __put_user((current->exec_domain + && current->exec_domain->signal_invmap + && sig < 32 + ? current->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); + if (err) + goto give_sigsegv; + + /* Create the ucontext. */ + err |= __put_user(0, &frame->uc.uc_flags); + err |= __put_user(0, &frame->uc.uc_link); + err |= __put_user(current->sas_ss_sp, &frame->uc.uc_stack.ss_sp); + err |= __put_user(sas_ss_flags(regs->esp), + &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, &frame->fpstate, + regs, set->sig[0]); + err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set)); + if (err) + goto give_sigsegv; + + /* Set up to return from userspace. If provided, use a stub + already in userspace. */ + if (ka->sa.sa_flags & SA_RESTORER) { + err |= __put_user(ka->sa.sa_restorer, &frame->pretcode); + } else { + err |= __put_user(frame->retcode, &frame->pretcode); + /* This is movl $,%eax ; int $0x80 */ + err |= __put_user(0xb8, (char *)(frame->retcode+0)); + err |= __put_user(__NR_rt_sigreturn, (int *)(frame->retcode+1)); + err |= __put_user(0x80cd, (short *)(frame->retcode+5)); + } + + if (err) + goto give_sigsegv; + + /* Set up registers for signal handler */ + regs->esp = (unsigned long) frame; + regs->eip = (unsigned long) ka->sa.sa_handler; + + set_fs(USER_DS); + regs->xds = __USER_DS; + regs->xes = __USER_DS; + regs->xss = __USER_DS; + regs->xcs = __USER_CS; + regs->eflags &= ~TF_MASK; + +#if DEBUG_SIG + printk("SIG deliver (%s:%d): sp=%p pc=%p ra=%p\n", + current->comm, current->pid, frame, regs->eip, frame->pretcode); +#endif + + return; + +give_sigsegv: + if (sig == SIGSEGV) + ka->sa.sa_handler = SIG_DFL; + force_sig(SIGSEGV, current); +} + +/* + * 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) +{ + /* Are we from a system call? */ + if (regs->orig_eax >= 0) { + /* If so, check system call restarting.. */ + switch (regs->eax) { + case -ERESTARTNOHAND: + regs->eax = -EINTR; + break; + + case -ERESTARTSYS: + if (!(ka->sa.sa_flags & SA_RESTART)) { + regs->eax = -EINTR; + break; + } + /* fallthrough */ + case -ERESTARTNOINTR: + regs->eax = regs->orig_eax; + regs->eip -= 2; + } + } + + /* 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->sigmask_lock); + sigorsets(¤t->blocked,¤t->blocked,&ka->sa.sa_mask); + sigaddset(¤t->blocked,sig); + recalc_sigpending(current); + spin_unlock_irq(¤t->sigmask_lock); + } +} + +/* + * 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. + */ +int do_signal(struct pt_regs *regs, sigset_t *oldset) +{ + siginfo_t info; + struct k_sigaction *ka; + + /* + * 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 ((regs->xcs & 2) != 2) + return 1; + + if (!oldset) + oldset = ¤t->blocked; + + for (;;) { + unsigned long signr; + + spin_lock_irq(¤t->sigmask_lock); + signr = dequeue_signal(¤t->blocked, &info); + spin_unlock_irq(¤t->sigmask_lock); + + if (!signr) + break; + + if ((current->ptrace & PT_PTRACED) && signr != SIGKILL) { + /* Let the debugger run. */ + current->exit_code = signr; + current->state = TASK_STOPPED; + notify_parent(current, SIGCHLD); + schedule(); + + /* We're back. Did the debugger cancel the sig? */ + if (!(signr = current->exit_code)) + continue; + current->exit_code = 0; + + /* The debugger continued. Ignore SIGSTOP. */ + if (signr == SIGSTOP) + continue; + + /* Update the siginfo structure. Is this good? */ + if (signr != info.si_signo) { + info.si_signo = signr; + info.si_errno = 0; + info.si_code = SI_USER; + info.si_pid = current->p_pptr->pid; + info.si_uid = current->p_pptr->uid; + } + + /* If the (new) signal is now blocked, requeue it. */ + if (sigismember(¤t->blocked, signr)) { + send_sig_info(signr, &info, current); + continue; + } + } + + ka = ¤t->sig->action[signr-1]; + if (ka->sa.sa_handler == SIG_IGN) { + if (signr != SIGCHLD) + continue; + /* Check for SIGCHLD: it's special. */ + while (sys_wait4(-1, NULL, WNOHANG, NULL) > 0) + /* nothing */; + continue; + } + + if (ka->sa.sa_handler == SIG_DFL) { + int exit_code = signr; + + /* Init gets no signals it doesn't want. */ + if (current->pid == 1) + continue; + + switch (signr) { + case SIGCONT: case SIGCHLD: case SIGWINCH: case SIGURG: + continue; + + case SIGTSTP: case SIGTTIN: case SIGTTOU: + if (is_orphaned_pgrp(current->pgrp)) + continue; + /* FALLTHRU */ + + case SIGSTOP: { + struct signal_struct *sig; + current->state = TASK_STOPPED; + current->exit_code = signr; + sig = current->p_pptr->sig; + if (sig && !(sig->action[SIGCHLD-1].sa.sa_flags & SA_NOCLDSTOP)) + notify_parent(current, SIGCHLD); + schedule(); + continue; + } + + case SIGQUIT: case SIGILL: case SIGTRAP: + case SIGABRT: case SIGFPE: case SIGSEGV: + case SIGBUS: case SIGSYS: case SIGXCPU: case SIGXFSZ: + if (do_coredump(signr, regs)) + exit_code |= 0x80; + /* FALLTHRU */ + + default: + sig_exit(signr, exit_code, &info); + /* NOTREACHED */ + } + } + + /* Reenable any watchpoints before delivering the + * signal to user space. The processor register will + * have been cleared if the watchpoint triggered + * inside the kernel. + */ + if ( current->thread.debugreg[7] != 0 ) + HYPERVISOR_set_debugreg(7, current->thread.debugreg[7]); + + /* Whee! Actually deliver the signal. */ + handle_signal(signr, ka, &info, oldset, regs); + return 1; + } + + /* Did we come from a system call? */ + if (regs->orig_eax >= 0) { + /* Restart the system call - no handlers present */ + if (regs->eax == -ERESTARTNOHAND || + regs->eax == -ERESTARTSYS || + regs->eax == -ERESTARTNOINTR) { + regs->eax = regs->orig_eax; + regs->eip -= 2; + } + } + return 0; +} |