2005-04-17 06:20:36 +08:00
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/*
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* Copyright (C) 1991, 1992 Linus Torvalds
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*
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* 1997-11-28 Modified for POSIX.1b signals by Richard Henderson
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* 2000-06-20 Pentium III FXSR, SSE support by Gareth Hughes
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*/
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#include <linux/sched.h>
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#include <linux/mm.h>
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#include <linux/smp.h>
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#include <linux/kernel.h>
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#include <linux/signal.h>
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#include <linux/errno.h>
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#include <linux/wait.h>
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#include <linux/unistd.h>
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#include <linux/stddef.h>
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#include <linux/personality.h>
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#include <linux/suspend.h>
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#include <linux/ptrace.h>
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#include <linux/elf.h>
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2007-02-13 20:26:26 +08:00
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#include <linux/binfmts.h>
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2005-04-17 06:20:36 +08:00
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#include <asm/processor.h>
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#include <asm/ucontext.h>
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#include <asm/uaccess.h>
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#include <asm/i387.h>
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2007-10-11 17:12:46 +08:00
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#include "sigframe_32.h"
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2005-04-17 06:20:36 +08:00
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#define DEBUG_SIG 0
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#define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
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/*
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* Atomically swap in the new signal mask, and wait for a signal.
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*/
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asmlinkage int
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sys_sigsuspend(int history0, int history1, old_sigset_t mask)
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{
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mask &= _BLOCKABLE;
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spin_lock_irq(¤t->sighand->siglock);
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2006-01-19 09:44:00 +08:00
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current->saved_sigmask = current->blocked;
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2005-04-17 06:20:36 +08:00
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siginitset(¤t->blocked, mask);
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recalc_sigpending();
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spin_unlock_irq(¤t->sighand->siglock);
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2006-01-19 09:44:00 +08:00
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current->state = TASK_INTERRUPTIBLE;
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schedule();
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set_thread_flag(TIF_RESTORE_SIGMASK);
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return -ERESTARTNOHAND;
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2005-04-17 06:20:36 +08:00
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}
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asmlinkage int
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sys_sigaction(int sig, const struct old_sigaction __user *act,
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struct old_sigaction __user *oact)
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{
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struct k_sigaction new_ka, old_ka;
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int ret;
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if (act) {
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old_sigset_t mask;
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if (!access_ok(VERIFY_READ, act, sizeof(*act)) ||
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__get_user(new_ka.sa.sa_handler, &act->sa_handler) ||
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__get_user(new_ka.sa.sa_restorer, &act->sa_restorer))
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return -EFAULT;
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__get_user(new_ka.sa.sa_flags, &act->sa_flags);
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__get_user(mask, &act->sa_mask);
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siginitset(&new_ka.sa.sa_mask, mask);
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}
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ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);
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if (!ret && oact) {
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if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)) ||
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__put_user(old_ka.sa.sa_handler, &oact->sa_handler) ||
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__put_user(old_ka.sa.sa_restorer, &oact->sa_restorer))
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return -EFAULT;
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__put_user(old_ka.sa.sa_flags, &oact->sa_flags);
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__put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask);
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}
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return ret;
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}
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asmlinkage int
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sys_sigaltstack(unsigned long ebx)
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{
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/* This is needed to make gcc realize it doesn't own the "struct pt_regs" */
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struct pt_regs *regs = (struct pt_regs *)&ebx;
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const stack_t __user *uss = (const stack_t __user *)ebx;
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stack_t __user *uoss = (stack_t __user *)regs->ecx;
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return do_sigaltstack(uss, uoss, regs->esp);
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}
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/*
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* Do a signal return; undo the signal stack.
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*/
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static int
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restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc, int *peax)
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{
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unsigned int err = 0;
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/* Always make any pending restarted system calls return -EINTR */
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current_thread_info()->restart_block.fn = do_no_restart_syscall;
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#define COPY(x) err |= __get_user(regs->x, &sc->x)
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#define COPY_SEG(seg) \
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{ unsigned short tmp; \
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err |= __get_user(tmp, &sc->seg); \
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regs->x##seg = tmp; }
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#define COPY_SEG_STRICT(seg) \
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{ unsigned short tmp; \
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err |= __get_user(tmp, &sc->seg); \
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regs->x##seg = tmp|3; }
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#define GET_SEG(seg) \
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{ unsigned short tmp; \
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err |= __get_user(tmp, &sc->seg); \
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loadsegment(seg,tmp); }
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2006-03-23 18:59:40 +08:00
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#define FIX_EFLAGS (X86_EFLAGS_AC | X86_EFLAGS_RF | \
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X86_EFLAGS_OF | X86_EFLAGS_DF | \
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2005-04-17 06:20:36 +08:00
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X86_EFLAGS_TF | X86_EFLAGS_SF | X86_EFLAGS_ZF | \
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X86_EFLAGS_AF | X86_EFLAGS_PF | X86_EFLAGS_CF)
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2007-02-13 20:26:20 +08:00
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GET_SEG(gs);
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COPY_SEG(fs);
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2005-04-17 06:20:36 +08:00
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COPY_SEG(es);
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COPY_SEG(ds);
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COPY(edi);
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COPY(esi);
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COPY(ebp);
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COPY(esp);
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COPY(ebx);
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COPY(edx);
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COPY(ecx);
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COPY(eip);
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COPY_SEG_STRICT(cs);
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COPY_SEG_STRICT(ss);
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{
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unsigned int tmpflags;
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err |= __get_user(tmpflags, &sc->eflags);
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regs->eflags = (regs->eflags & ~FIX_EFLAGS) | (tmpflags & FIX_EFLAGS);
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regs->orig_eax = -1; /* disable syscall checks */
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}
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{
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struct _fpstate __user * buf;
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err |= __get_user(buf, &sc->fpstate);
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if (buf) {
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if (!access_ok(VERIFY_READ, buf, sizeof(*buf)))
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goto badframe;
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err |= restore_i387(buf);
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} else {
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struct task_struct *me = current;
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if (used_math()) {
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clear_fpu(me);
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clear_used_math();
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}
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}
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}
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err |= __get_user(*peax, &sc->eax);
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return err;
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badframe:
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return 1;
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}
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asmlinkage int sys_sigreturn(unsigned long __unused)
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{
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struct pt_regs *regs = (struct pt_regs *) &__unused;
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struct sigframe __user *frame = (struct sigframe __user *)(regs->esp - 8);
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sigset_t set;
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int eax;
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if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
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goto badframe;
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if (__get_user(set.sig[0], &frame->sc.oldmask)
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|| (_NSIG_WORDS > 1
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&& __copy_from_user(&set.sig[1], &frame->extramask,
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sizeof(frame->extramask))))
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goto badframe;
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sigdelsetmask(&set, ~_BLOCKABLE);
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spin_lock_irq(¤t->sighand->siglock);
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current->blocked = set;
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recalc_sigpending();
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spin_unlock_irq(¤t->sighand->siglock);
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if (restore_sigcontext(regs, &frame->sc, &eax))
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goto badframe;
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return eax;
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badframe:
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2007-07-22 17:12:28 +08:00
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if (show_unhandled_signals && printk_ratelimit())
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printk("%s%s[%d] bad frame in sigreturn frame:%p eip:%lx"
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" esp:%lx oeax:%lx\n",
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2007-10-19 14:40:41 +08:00
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task_pid_nr(current) > 1 ? KERN_INFO : KERN_EMERG,
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current->comm, task_pid_nr(current), frame, regs->eip,
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2007-07-22 17:12:28 +08:00
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regs->esp, regs->orig_eax);
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2005-04-17 06:20:36 +08:00
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force_sig(SIGSEGV, current);
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return 0;
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}
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asmlinkage int sys_rt_sigreturn(unsigned long __unused)
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{
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struct pt_regs *regs = (struct pt_regs *) &__unused;
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struct rt_sigframe __user *frame = (struct rt_sigframe __user *)(regs->esp - 4);
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sigset_t set;
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int eax;
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if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
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goto badframe;
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if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
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goto badframe;
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sigdelsetmask(&set, ~_BLOCKABLE);
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spin_lock_irq(¤t->sighand->siglock);
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current->blocked = set;
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recalc_sigpending();
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spin_unlock_irq(¤t->sighand->siglock);
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if (restore_sigcontext(regs, &frame->uc.uc_mcontext, &eax))
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goto badframe;
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if (do_sigaltstack(&frame->uc.uc_stack, NULL, regs->esp) == -EFAULT)
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goto badframe;
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return eax;
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badframe:
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force_sig(SIGSEGV, current);
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return 0;
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}
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/*
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* Set up a signal frame.
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*/
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static int
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setup_sigcontext(struct sigcontext __user *sc, struct _fpstate __user *fpstate,
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struct pt_regs *regs, unsigned long mask)
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{
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int tmp, err = 0;
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2007-02-13 20:26:20 +08:00
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err |= __put_user(regs->xfs, (unsigned int __user *)&sc->fs);
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savesegment(gs, tmp);
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err |= __put_user(tmp, (unsigned int __user *)&sc->gs);
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2005-04-17 06:20:36 +08:00
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err |= __put_user(regs->xes, (unsigned int __user *)&sc->es);
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err |= __put_user(regs->xds, (unsigned int __user *)&sc->ds);
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err |= __put_user(regs->edi, &sc->edi);
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err |= __put_user(regs->esi, &sc->esi);
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err |= __put_user(regs->ebp, &sc->ebp);
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err |= __put_user(regs->esp, &sc->esp);
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err |= __put_user(regs->ebx, &sc->ebx);
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err |= __put_user(regs->edx, &sc->edx);
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err |= __put_user(regs->ecx, &sc->ecx);
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err |= __put_user(regs->eax, &sc->eax);
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err |= __put_user(current->thread.trap_no, &sc->trapno);
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err |= __put_user(current->thread.error_code, &sc->err);
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err |= __put_user(regs->eip, &sc->eip);
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err |= __put_user(regs->xcs, (unsigned int __user *)&sc->cs);
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err |= __put_user(regs->eflags, &sc->eflags);
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err |= __put_user(regs->esp, &sc->esp_at_signal);
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err |= __put_user(regs->xss, (unsigned int __user *)&sc->ss);
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tmp = save_i387(fpstate);
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if (tmp < 0)
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err = 1;
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else
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err |= __put_user(tmp ? fpstate : NULL, &sc->fpstate);
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/* non-iBCS2 extensions.. */
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err |= __put_user(mask, &sc->oldmask);
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err |= __put_user(current->thread.cr2, &sc->cr2);
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return err;
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}
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/*
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* Determine which stack to use..
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*/
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static inline void __user *
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get_sigframe(struct k_sigaction *ka, struct pt_regs * regs, size_t frame_size)
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{
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unsigned long esp;
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/* Default to using normal stack */
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esp = regs->esp;
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/* This is the X/Open sanctioned signal stack switching. */
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if (ka->sa.sa_flags & SA_ONSTACK) {
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if (sas_ss_flags(esp) == 0)
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esp = current->sas_ss_sp + current->sas_ss_size;
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}
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/* This is the legacy signal stack switching. */
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else if ((regs->xss & 0xffff) != __USER_DS &&
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!(ka->sa.sa_flags & SA_RESTORER) &&
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ka->sa.sa_restorer) {
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esp = (unsigned long) ka->sa.sa_restorer;
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}
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2005-10-10 00:54:23 +08:00
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esp -= frame_size;
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/* Align the stack pointer according to the i386 ABI,
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* i.e. so that on function entry ((sp + 4) & 15) == 0. */
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esp = ((esp + 4) & -16ul) - 4;
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return (void __user *) esp;
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2005-04-17 06:20:36 +08:00
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}
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/* These symbols are defined with the addresses in the vsyscall page.
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See vsyscall-sigreturn.S. */
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extern void __user __kernel_sigreturn;
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extern void __user __kernel_rt_sigreturn;
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|
2005-06-23 15:08:21 +08:00
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static int setup_frame(int sig, struct k_sigaction *ka,
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sigset_t *set, struct pt_regs * regs)
|
2005-04-17 06:20:36 +08:00
|
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{
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void __user *restorer;
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struct sigframe __user *frame;
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int err = 0;
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int usig;
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frame = get_sigframe(ka, regs, sizeof(*frame));
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if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
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goto give_sigsegv;
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usig = current_thread_info()->exec_domain
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&& current_thread_info()->exec_domain->signal_invmap
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&& sig < 32
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? current_thread_info()->exec_domain->signal_invmap[sig]
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: sig;
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err = __put_user(usig, &frame->sig);
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if (err)
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goto give_sigsegv;
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|
|
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;
|
|
|
|
}
|
|
|
|
|
2007-02-13 20:26:26 +08:00
|
|
|
if (current->binfmt->hasvdso)
|
|
|
|
restorer = (void *)VDSO_SYM(&__kernel_sigreturn);
|
|
|
|
else
|
|
|
|
restorer = (void *)&frame->retcode;
|
2005-04-17 06:20:36 +08:00
|
|
|
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;
|
|
|
|
|
|
|
|
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
|
|
|
|
|
2006-01-19 09:44:00 +08:00
|
|
|
return 0;
|
2005-04-17 06:20:36 +08:00
|
|
|
|
|
|
|
give_sigsegv:
|
|
|
|
force_sigsegv(sig, current);
|
2006-01-19 09:44:00 +08:00
|
|
|
return -EFAULT;
|
2005-04-17 06:20:36 +08:00
|
|
|
}
|
|
|
|
|
2005-06-23 15:08:21 +08:00
|
|
|
static int setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
|
2005-04-17 06:20:36 +08:00
|
|
|
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. */
|
[PATCH] vdso: randomize the i386 vDSO by moving it into a vma
Move the i386 VDSO down into a vma and thus randomize it.
Besides the security implications, this feature also helps debuggers, which
can COW a vma-backed VDSO just like a normal DSO and can thus do
single-stepping and other debugging features.
It's good for hypervisors (Xen, VMWare) too, which typically live in the same
high-mapped address space as the VDSO, hence whenever the VDSO is used, they
get lots of guest pagefaults and have to fix such guest accesses up - which
slows things down instead of speeding things up (the primary purpose of the
VDSO).
There's a new CONFIG_COMPAT_VDSO (default=y) option, which provides support
for older glibcs that still rely on a prelinked high-mapped VDSO. Newer
distributions (using glibc 2.3.3 or later) can turn this option off. Turning
it off is also recommended for security reasons: attackers cannot use the
predictable high-mapped VDSO page as syscall trampoline anymore.
There is a new vdso=[0|1] boot option as well, and a runtime
/proc/sys/vm/vdso_enabled sysctl switch, that allows the VDSO to be turned
on/off.
(This version of the VDSO-randomization patch also has working ELF
coredumping, the previous patch crashed in the coredumping code.)
This code is a combined work of the exec-shield VDSO randomization
code and Gerd Hoffmann's hypervisor-centric VDSO patch. Rusty Russell
started this patch and i completed it.
[akpm@osdl.org: cleanups]
[akpm@osdl.org: compile fix]
[akpm@osdl.org: compile fix 2]
[akpm@osdl.org: compile fix 3]
[akpm@osdl.org: revernt MAXMEM change]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Arjan van de Ven <arjan@infradead.org>
Cc: Gerd Hoffmann <kraxel@suse.de>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Zachary Amsden <zach@vmware.com>
Cc: Andi Kleen <ak@muc.de>
Cc: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27 17:53:50 +08:00
|
|
|
restorer = (void *)VDSO_SYM(&__kernel_rt_sigreturn);
|
2005-04-17 06:20:36 +08:00
|
|
|
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;
|
|
|
|
|
|
|
|
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
|
|
|
|
|
2006-01-19 09:44:00 +08:00
|
|
|
return 0;
|
2005-04-17 06:20:36 +08:00
|
|
|
|
|
|
|
give_sigsegv:
|
|
|
|
force_sigsegv(sig, current);
|
2006-01-19 09:44:00 +08:00
|
|
|
return -EFAULT;
|
2005-04-17 06:20:36 +08:00
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* OK, we're invoking a handler
|
|
|
|
*/
|
|
|
|
|
2005-06-23 15:08:21 +08:00
|
|
|
static int
|
2005-04-17 06:20:36 +08:00
|
|
|
handle_signal(unsigned long sig, siginfo_t *info, struct k_sigaction *ka,
|
|
|
|
sigset_t *oldset, struct pt_regs * regs)
|
|
|
|
{
|
2005-06-23 15:08:21 +08:00
|
|
|
int ret;
|
|
|
|
|
2005-04-17 06:20:36 +08:00
|
|
|
/* 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)
|
2005-06-23 15:08:21 +08:00
|
|
|
ret = setup_rt_frame(sig, ka, info, oldset, regs);
|
2005-04-17 06:20:36 +08:00
|
|
|
else
|
2005-06-23 15:08:21 +08:00
|
|
|
ret = setup_frame(sig, ka, oldset, regs);
|
2005-04-17 06:20:36 +08:00
|
|
|
|
2006-01-19 09:44:00 +08:00
|
|
|
if (ret == 0) {
|
2005-04-17 06:20:36 +08:00
|
|
|
spin_lock_irq(¤t->sighand->siglock);
|
|
|
|
sigorsets(¤t->blocked,¤t->blocked,&ka->sa.sa_mask);
|
[PATCH] convert signal handling of NODEFER to act like other Unix boxes.
It has been reported that the way Linux handles NODEFER for signals is
not consistent with the way other Unix boxes handle it. I've written a
program to test the behavior of how this flag affects signals and had
several reports from people who ran this on various Unix boxes,
confirming that Linux seems to be unique on the way this is handled.
The way NODEFER affects signals on other Unix boxes is as follows:
1) If NODEFER is set, other signals in sa_mask are still blocked.
2) If NODEFER is set and the signal is in sa_mask, then the signal is
still blocked. (Note: this is the behavior of all tested but Linux _and_
NetBSD 2.0 *).
The way NODEFER affects signals on Linux:
1) If NODEFER is set, other signals are _not_ blocked regardless of
sa_mask (Even NetBSD doesn't do this).
2) If NODEFER is set and the signal is in sa_mask, then the signal being
handled is not blocked.
The patch converts signal handling in all current Linux architectures to
the way most Unix boxes work.
Unix boxes that were tested: DU4, AIX 5.2, Irix 6.5, NetBSD 2.0, SFU
3.5 on WinXP, AIX 5.3, Mac OSX, and of course Linux 2.6.13-rcX.
* NetBSD was the only other Unix to behave like Linux on point #2. The
main concern was brought up by point #1 which even NetBSD isn't like
Linux. So with this patch, we leave NetBSD as the lonely one that
behaves differently here with #2.
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-08-29 23:44:09 +08:00
|
|
|
if (!(ka->sa.sa_flags & SA_NODEFER))
|
|
|
|
sigaddset(¤t->blocked,sig);
|
2005-04-17 06:20:36 +08:00
|
|
|
recalc_sigpending();
|
|
|
|
spin_unlock_irq(¤t->sighand->siglock);
|
|
|
|
}
|
2005-06-23 15:08:21 +08:00
|
|
|
|
|
|
|
return ret;
|
2005-04-17 06:20:36 +08:00
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* 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.
|
|
|
|
*/
|
2006-01-19 09:44:00 +08:00
|
|
|
static void fastcall do_signal(struct pt_regs *regs)
|
2005-04-17 06:20:36 +08:00
|
|
|
{
|
|
|
|
siginfo_t info;
|
|
|
|
int signr;
|
|
|
|
struct k_sigaction ka;
|
2006-01-19 09:44:00 +08:00
|
|
|
sigset_t *oldset;
|
2005-04-17 06:20:36 +08:00
|
|
|
|
|
|
|
/*
|
|
|
|
* 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
|
2005-09-04 06:56:43 +08:00
|
|
|
* if so. vm86 regs switched out by assembly code
|
|
|
|
* before reaching here, so testing against kernel
|
|
|
|
* CS suffices.
|
2005-04-17 06:20:36 +08:00
|
|
|
*/
|
2005-06-23 15:08:45 +08:00
|
|
|
if (!user_mode(regs))
|
2006-01-19 09:44:00 +08:00
|
|
|
return;
|
2005-04-17 06:20:36 +08:00
|
|
|
|
2006-01-19 09:44:00 +08:00
|
|
|
if (test_thread_flag(TIF_RESTORE_SIGMASK))
|
|
|
|
oldset = ¤t->saved_sigmask;
|
|
|
|
else
|
2005-04-17 06:20:36 +08:00
|
|
|
oldset = ¤t->blocked;
|
|
|
|
|
|
|
|
signr = get_signal_to_deliver(&info, &ka, regs, NULL);
|
|
|
|
if (signr > 0) {
|
2007-10-20 07:13:56 +08:00
|
|
|
/* Re-enable any watchpoints before delivering the
|
2005-04-17 06:20:36 +08:00
|
|
|
* signal to user space. The processor register will
|
|
|
|
* have been cleared if the watchpoint triggered
|
|
|
|
* inside the kernel.
|
|
|
|
*/
|
2006-01-19 09:44:00 +08:00
|
|
|
if (unlikely(current->thread.debugreg[7]))
|
2005-06-23 15:08:43 +08:00
|
|
|
set_debugreg(current->thread.debugreg[7], 7);
|
2005-04-17 06:20:36 +08:00
|
|
|
|
|
|
|
/* Whee! Actually deliver the signal. */
|
2006-01-19 09:44:00 +08:00
|
|
|
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;
|
2005-04-17 06:20:36 +08:00
|
|
|
}
|
|
|
|
|
|
|
|
/* Did we come from a system call? */
|
|
|
|
if (regs->orig_eax >= 0) {
|
|
|
|
/* Restart the system call - no handlers present */
|
2006-01-19 09:44:00 +08:00
|
|
|
switch (regs->eax) {
|
|
|
|
case -ERESTARTNOHAND:
|
|
|
|
case -ERESTARTSYS:
|
|
|
|
case -ERESTARTNOINTR:
|
2005-04-17 06:20:36 +08:00
|
|
|
regs->eax = regs->orig_eax;
|
|
|
|
regs->eip -= 2;
|
2006-01-19 09:44:00 +08:00
|
|
|
break;
|
|
|
|
|
|
|
|
case -ERESTART_RESTARTBLOCK:
|
2005-04-17 06:20:36 +08:00
|
|
|
regs->eax = __NR_restart_syscall;
|
|
|
|
regs->eip -= 2;
|
2006-01-19 09:44:00 +08:00
|
|
|
break;
|
2005-04-17 06:20:36 +08:00
|
|
|
}
|
|
|
|
}
|
2006-01-19 09:44:00 +08:00
|
|
|
|
|
|
|
/* 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);
|
|
|
|
}
|
2005-04-17 06:20:36 +08:00
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* notification of userspace execution resumption
|
2006-01-19 09:44:00 +08:00
|
|
|
* - triggered by the TIF_WORK_MASK flags
|
2005-04-17 06:20:36 +08:00
|
|
|
*/
|
|
|
|
__attribute__((regparm(3)))
|
2006-01-19 09:44:00 +08:00
|
|
|
void do_notify_resume(struct pt_regs *regs, void *_unused,
|
2005-04-17 06:20:36 +08:00
|
|
|
__u32 thread_info_flags)
|
|
|
|
{
|
|
|
|
/* Pending single-step? */
|
|
|
|
if (thread_info_flags & _TIF_SINGLESTEP) {
|
|
|
|
regs->eflags |= TF_MASK;
|
|
|
|
clear_thread_flag(TIF_SINGLESTEP);
|
|
|
|
}
|
2006-01-19 09:44:00 +08:00
|
|
|
|
2005-04-17 06:20:36 +08:00
|
|
|
/* deal with pending signal delivery */
|
2006-01-19 09:44:00 +08:00
|
|
|
if (thread_info_flags & (_TIF_SIGPENDING | _TIF_RESTORE_SIGMASK))
|
|
|
|
do_signal(regs);
|
2005-04-17 06:20:36 +08:00
|
|
|
|
|
|
|
clear_thread_flag(TIF_IRET);
|
|
|
|
}
|