diff options
Diffstat (limited to 'arch/i386/kernel/signal.c')
| -rw-r--r-- | arch/i386/kernel/signal.c | 667 |
1 files changed, 0 insertions, 667 deletions
diff --git a/arch/i386/kernel/signal.c b/arch/i386/kernel/signal.c deleted file mode 100644 index f5dd85656c18..000000000000 --- a/arch/i386/kernel/signal.c +++ /dev/null @@ -1,667 +0,0 @@ -/* - * 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/kernel.h> -#include <linux/signal.h> -#include <linux/errno.h> -#include <linux/wait.h> -#include <linux/unistd.h> -#include <linux/stddef.h> -#include <linux/personality.h> -#include <linux/suspend.h> -#include <linux/ptrace.h> -#include <linux/elf.h> -#include <linux/binfmts.h> -#include <asm/processor.h> -#include <asm/ucontext.h> -#include <asm/uaccess.h> -#include <asm/i387.h> -#include "sigframe.h" - -#define DEBUG_SIG 0 - -#define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP))) - -/* - * Atomically swap in the new signal mask, and wait for a signal. - */ -asmlinkage int -sys_sigsuspend(int history0, int history1, old_sigset_t mask) -{ - mask &= _BLOCKABLE; - spin_lock_irq(¤t->sighand->siglock); - current->saved_sigmask = current->blocked; - siginitset(¤t->blocked, mask); - recalc_sigpending(); - spin_unlock_irq(¤t->sighand->siglock); - - current->state = TASK_INTERRUPTIBLE; - schedule(); - set_thread_flag(TIF_RESTORE_SIGMASK); - return -ERESTARTNOHAND; -} - -asmlinkage int -sys_sigaction(int sig, const struct old_sigaction __user *act, - struct old_sigaction __user *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(unsigned long ebx) -{ - /* This is needed to make gcc realize it doesn't own the "struct pt_regs" */ - struct pt_regs *regs = (struct pt_regs *)&ebx; - const stack_t __user *uss = (const stack_t __user *)ebx; - stack_t __user *uoss = (stack_t __user *)regs->ecx; - - return do_sigaltstack(uss, uoss, regs->esp); -} - - -/* - * Do a signal return; undo the signal stack. - */ - -static int -restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc, int *peax) -{ - unsigned int err = 0; - - /* Always make any pending restarted system calls return -EINTR */ - current_thread_info()->restart_block.fn = do_no_restart_syscall; - -#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); } - -#define FIX_EFLAGS (X86_EFLAGS_AC | X86_EFLAGS_RF | \ - X86_EFLAGS_OF | X86_EFLAGS_DF | \ - X86_EFLAGS_TF | X86_EFLAGS_SF | X86_EFLAGS_ZF | \ - X86_EFLAGS_AF | X86_EFLAGS_PF | X86_EFLAGS_CF) - - GET_SEG(gs); - COPY_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 & ~FIX_EFLAGS) | (tmpflags & FIX_EFLAGS); - regs->orig_eax = -1; /* disable syscall checks */ - } - - { - struct _fpstate __user * buf; - err |= __get_user(buf, &sc->fpstate); - if (buf) { - if (!access_ok(VERIFY_READ, buf, sizeof(*buf))) - goto badframe; - err |= restore_i387(buf); - } else { - struct task_struct *me = current; - if (used_math()) { - clear_fpu(me); - clear_used_math(); - } - } - } - - 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 __user *frame = (struct sigframe __user *)(regs->esp - 8); - sigset_t set; - int eax; - - 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, &eax)) - goto badframe; - return eax; - -badframe: - if (show_unhandled_signals && printk_ratelimit()) - printk("%s%s[%d] bad frame in sigreturn frame:%p eip:%lx" - " esp:%lx oeax:%lx\n", - current->pid > 1 ? KERN_INFO : KERN_EMERG, - current->comm, current->pid, frame, regs->eip, - regs->esp, regs->orig_eax); - - 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 __user *frame = (struct rt_sigframe __user *)(regs->esp - 4); - sigset_t set; - int eax; - - 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, &eax)) - goto badframe; - - if (do_sigaltstack(&frame->uc.uc_stack, NULL, regs->esp) == -EFAULT) - goto badframe; - - return eax; - -badframe: - force_sig(SIGSEGV, current); - return 0; -} - -/* - * Set up a signal frame. - */ - -static int -setup_sigcontext(struct sigcontext __user *sc, struct _fpstate __user *fpstate, - struct pt_regs *regs, unsigned long mask) -{ - int tmp, err = 0; - - err |= __put_user(regs->xfs, (unsigned int __user *)&sc->fs); - savesegment(gs, tmp); - err |= __put_user(tmp, (unsigned int __user *)&sc->gs); - - err |= __put_user(regs->xes, (unsigned int __user *)&sc->es); - err |= __put_user(regs->xds, (unsigned int __user *)&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 __user *)&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 __user *)&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 __user * -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; - } - - esp -= frame_size; - /* Align the stack pointer according to the i386 ABI, - * i.e. so that on function entry ((sp + 4) & 15) == 0. */ - esp = ((esp + 4) & -16ul) - 4; - return (void __user *) esp; -} - -/* These symbols are defined with the addresses in the vsyscall page. - See vsyscall-sigreturn.S. */ -extern void __user __kernel_sigreturn; -extern void __user __kernel_rt_sigreturn; - -static int setup_frame(int sig, struct k_sigaction *ka, - sigset_t *set, struct pt_regs * regs) -{ - void __user *restorer; - struct sigframe __user *frame; - int err = 0; - int usig; - - frame = get_sigframe(ka, regs, sizeof(*frame)); - - if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) - goto give_sigsegv; - - usig = current_thread_info()->exec_domain - && current_thread_info()->exec_domain->signal_invmap - && sig < 32 - ? current_thread_info()->exec_domain->signal_invmap[sig] - : sig; - - err = __put_user(usig, &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; - } - - if (current->binfmt->hasvdso) - restorer = (void *)VDSO_SYM(&__kernel_sigreturn); - else - restorer = (void *)&frame->retcode; - if (ka->sa.sa_flags & SA_RESTORER) - restorer = ka->sa.sa_restorer; - - /* Set up to return from userspace. */ - err |= __put_user(restorer, &frame->pretcode); - - /* - * This is popl %eax ; movl $,%eax ; int $0x80 - * - * WE DO NOT USE IT ANY MORE! It's only left here for historical - * reasons and because gdb uses it as a signature to notice - * signal handler stack frames. - */ - err |= __put_user(0xb858, (short __user *)(frame->retcode+0)); - err |= __put_user(__NR_sigreturn, (int __user *)(frame->retcode+2)); - err |= __put_user(0x80cd, (short __user *)(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; - regs->eax = (unsigned long) sig; - regs->edx = (unsigned long) 0; - regs->ecx = (unsigned long) 0; - - set_fs(USER_DS); - regs->xds = __USER_DS; - regs->xes = __USER_DS; - regs->xss = __USER_DS; - regs->xcs = __USER_CS; - - /* - * Clear TF when entering the signal handler, but - * notify any tracer that was single-stepping it. - * The tracer may want to single-step inside the - * handler too. - */ - regs->eflags &= ~TF_MASK; - if (test_thread_flag(TIF_SINGLESTEP)) - ptrace_notify(SIGTRAP); - -#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 0; - -give_sigsegv: - force_sigsegv(sig, current); - return -EFAULT; -} - -static int setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info, - sigset_t *set, struct pt_regs * regs) -{ - void __user *restorer; - struct rt_sigframe __user *frame; - int err = 0; - int usig; - - frame = get_sigframe(ka, regs, sizeof(*frame)); - - if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) - goto give_sigsegv; - - usig = current_thread_info()->exec_domain - && current_thread_info()->exec_domain->signal_invmap - && sig < 32 - ? current_thread_info()->exec_domain->signal_invmap[sig] - : sig; - - err |= __put_user(usig, &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. */ - restorer = (void *)VDSO_SYM(&__kernel_rt_sigreturn); - if (ka->sa.sa_flags & SA_RESTORER) - restorer = ka->sa.sa_restorer; - err |= __put_user(restorer, &frame->pretcode); - - /* - * This is movl $,%eax ; int $0x80 - * - * WE DO NOT USE IT ANY MORE! It's only left here for historical - * reasons and because gdb uses it as a signature to notice - * signal handler stack frames. - */ - err |= __put_user(0xb8, (char __user *)(frame->retcode+0)); - err |= __put_user(__NR_rt_sigreturn, (int __user *)(frame->retcode+1)); - err |= __put_user(0x80cd, (short __user *)(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; - regs->eax = (unsigned long) usig; - regs->edx = (unsigned long) &frame->info; - regs->ecx = (unsigned long) &frame->uc; - - set_fs(USER_DS); - regs->xds = __USER_DS; - regs->xes = __USER_DS; - regs->xss = __USER_DS; - regs->xcs = __USER_CS; - - /* - * Clear TF when entering the signal handler, but - * notify any tracer that was single-stepping it. - * The tracer may want to single-step inside the - * handler too. - */ - regs->eflags &= ~TF_MASK; - if (test_thread_flag(TIF_SINGLESTEP)) - ptrace_notify(SIGTRAP); - -#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 0; - -give_sigsegv: - force_sigsegv(sig, current); - return -EFAULT; -} - -/* - * OK, we're invoking a handler - */ - -static int -handle_signal(unsigned long sig, siginfo_t *info, struct k_sigaction *ka, - sigset_t *oldset, struct pt_regs * regs) -{ - int ret; - - /* Are we from a system call? */ - if (regs->orig_eax >= 0) { - /* If so, check system call restarting.. */ - switch (regs->eax) { - case -ERESTART_RESTARTBLOCK: - 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; - } - } - - /* - * If TF is set due to a debugger (PT_DTRACE), clear the TF flag so - * that register information in the sigcontext is correct. - */ - if (unlikely(regs->eflags & TF_MASK) - && likely(current->ptrace & PT_DTRACE)) { - current->ptrace &= ~PT_DTRACE; - regs->eflags &= ~TF_MASK; - } - - /* Set up the stack frame */ - if (ka->sa.sa_flags & SA_SIGINFO) - ret = setup_rt_frame(sig, ka, info, oldset, regs); - else - ret = setup_frame(sig, ka, 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. - */ -static void fastcall do_signal(struct pt_regs *regs) -{ - siginfo_t info; - int signr; - struct k_sigaction ka; - sigset_t *oldset; - - /* - * 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. vm86 regs switched out by assembly code - * before reaching here, so testing against kernel - * CS suffices. - */ - if (!user_mode(regs)) - return; - - 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) { - /* 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 (unlikely(current->thread.debugreg[7])) - set_debugreg(current->thread.debugreg[7], 7); - - /* 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); - } - - return; - } - - /* Did we come from a system call? */ - if (regs->orig_eax >= 0) { - /* Restart the system call - no handlers present */ - switch (regs->eax) { - case -ERESTARTNOHAND: - case -ERESTARTSYS: - case -ERESTARTNOINTR: - regs->eax = regs->orig_eax; - regs->eip -= 2; - break; - - case -ERESTART_RESTARTBLOCK: - regs->eax = __NR_restart_syscall; - regs->eip -= 2; - break; - } - } - - /* 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 - * - triggered by the TIF_WORK_MASK flags - */ -__attribute__((regparm(3))) -void do_notify_resume(struct pt_regs *regs, void *_unused, - __u32 thread_info_flags) -{ - /* Pending single-step? */ - if (thread_info_flags & _TIF_SINGLESTEP) { - regs->eflags |= TF_MASK; - clear_thread_flag(TIF_SINGLESTEP); - } - - /* deal with pending signal delivery */ - if (thread_info_flags & (_TIF_SIGPENDING | _TIF_RESTORE_SIGMASK)) - do_signal(regs); - - clear_thread_flag(TIF_IRET); -} |