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76381fee7e
Make use of the user_mode macro where it's possible. This is useful for Xen because it will need only to redefine only the macro to a hypervisor call. Signed-off-by: Vincent Hanquez <vincent.hanquez@cl.cam.ac.uk> Cc: Ian Pratt <m+Ian.Pratt@cl.cam.ac.uk> Cc: Andi Kleen <ak@muc.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
496 lines
13 KiB
C
496 lines
13 KiB
C
/*
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* linux/arch/x86_64/kernel/signal.c
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*
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* Copyright (C) 1991, 1992 Linus Torvalds
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* Copyright (C) 2000, 2001, 2002 Andi Kleen SuSE Labs
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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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* 2000-2002 x86-64 support by Andi Kleen
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*
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* $Id: signal.c,v 1.18 2001/10/17 22:30:37 ak Exp $
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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/smp_lock.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/ptrace.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/compiler.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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#include <asm/proto.h>
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#include <asm/ia32_unistd.h>
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/* #define DEBUG_SIG 1 */
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#define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
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int ia32_setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
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sigset_t *set, struct pt_regs * regs);
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int ia32_setup_frame(int sig, struct k_sigaction *ka,
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sigset_t *set, struct pt_regs * regs);
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asmlinkage long
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sys_rt_sigsuspend(sigset_t __user *unewset, size_t sigsetsize, struct pt_regs *regs)
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{
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sigset_t saveset, newset;
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/* XXX: Don't preclude handling different sized sigset_t's. */
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if (sigsetsize != sizeof(sigset_t))
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return -EINVAL;
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if (copy_from_user(&newset, unewset, sizeof(newset)))
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return -EFAULT;
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sigdelsetmask(&newset, ~_BLOCKABLE);
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spin_lock_irq(¤t->sighand->siglock);
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saveset = current->blocked;
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current->blocked = newset;
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recalc_sigpending();
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spin_unlock_irq(¤t->sighand->siglock);
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#ifdef DEBUG_SIG
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printk("rt_sigsuspend savset(%lx) newset(%lx) regs(%p) rip(%lx)\n",
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saveset, newset, regs, regs->rip);
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#endif
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regs->rax = -EINTR;
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while (1) {
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current->state = TASK_INTERRUPTIBLE;
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schedule();
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if (do_signal(regs, &saveset))
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return -EINTR;
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}
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}
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asmlinkage long
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sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss,
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struct pt_regs *regs)
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{
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return do_sigaltstack(uss, uoss, regs->rsp);
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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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struct rt_sigframe
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{
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char __user *pretcode;
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struct ucontext uc;
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struct siginfo info;
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};
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static int
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restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc, unsigned long *prax)
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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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COPY(rdi); COPY(rsi); COPY(rbp); COPY(rsp); COPY(rbx);
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COPY(rdx); COPY(rcx); COPY(rip);
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COPY(r8);
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COPY(r9);
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COPY(r10);
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COPY(r11);
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COPY(r12);
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COPY(r13);
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COPY(r14);
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COPY(r15);
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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 & ~0x40DD5) | (tmpflags & 0x40DD5);
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regs->orig_rax = -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(*prax, &sc->rax);
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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 long sys_rt_sigreturn(struct pt_regs *regs)
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{
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struct rt_sigframe __user *frame;
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sigset_t set;
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unsigned long eax;
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frame = (struct rt_sigframe __user *)(regs->rsp - 8);
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if (!access_ok(VERIFY_READ, frame, sizeof(*frame))) {
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goto badframe;
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}
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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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}
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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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#ifdef DEBUG_SIG
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printk("%d sigreturn rip:%lx rsp:%lx frame:%p rax:%lx\n",current->pid,regs.rip,regs.rsp,frame,eax);
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#endif
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if (do_sigaltstack(&frame->uc.uc_stack, NULL, regs->rsp) == -EFAULT)
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goto badframe;
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return eax;
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badframe:
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signal_fault(regs,frame,"sigreturn");
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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 inline int
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setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs, unsigned long mask, struct task_struct *me)
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{
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int err = 0;
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err |= __put_user(0, &sc->gs);
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err |= __put_user(0, &sc->fs);
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err |= __put_user(regs->rdi, &sc->rdi);
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err |= __put_user(regs->rsi, &sc->rsi);
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err |= __put_user(regs->rbp, &sc->rbp);
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err |= __put_user(regs->rsp, &sc->rsp);
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err |= __put_user(regs->rbx, &sc->rbx);
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err |= __put_user(regs->rdx, &sc->rdx);
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err |= __put_user(regs->rcx, &sc->rcx);
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err |= __put_user(regs->rax, &sc->rax);
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err |= __put_user(regs->r8, &sc->r8);
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err |= __put_user(regs->r9, &sc->r9);
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err |= __put_user(regs->r10, &sc->r10);
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err |= __put_user(regs->r11, &sc->r11);
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err |= __put_user(regs->r12, &sc->r12);
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err |= __put_user(regs->r13, &sc->r13);
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err |= __put_user(regs->r14, &sc->r14);
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err |= __put_user(regs->r15, &sc->r15);
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err |= __put_user(me->thread.trap_no, &sc->trapno);
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err |= __put_user(me->thread.error_code, &sc->err);
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err |= __put_user(regs->rip, &sc->rip);
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err |= __put_user(regs->eflags, &sc->eflags);
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err |= __put_user(mask, &sc->oldmask);
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err |= __put_user(me->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 void __user *
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get_stack(struct k_sigaction *ka, struct pt_regs *regs, unsigned long size)
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{
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unsigned long rsp;
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/* Default to using normal stack - redzone*/
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rsp = regs->rsp - 128;
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/* This is the X/Open sanctioned signal stack switching. */
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/* RED-PEN: redzone on that stack? */
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if (ka->sa.sa_flags & SA_ONSTACK) {
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if (sas_ss_flags(rsp) == 0)
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rsp = current->sas_ss_sp + current->sas_ss_size;
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}
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return (void __user *)round_down(rsp - size, 16);
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}
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static int setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
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sigset_t *set, struct pt_regs * regs)
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{
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struct rt_sigframe __user *frame;
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struct _fpstate __user *fp = NULL;
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int err = 0;
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struct task_struct *me = current;
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if (used_math()) {
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fp = get_stack(ka, regs, sizeof(struct _fpstate));
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frame = (void __user *)round_down(
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(unsigned long)fp - sizeof(struct rt_sigframe), 16) - 8;
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if (!access_ok(VERIFY_WRITE, fp, sizeof(struct _fpstate)))
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goto give_sigsegv;
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if (save_i387(fp) < 0)
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err |= -1;
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} else
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frame = get_stack(ka, regs, sizeof(struct rt_sigframe)) - 8;
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if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
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goto give_sigsegv;
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if (ka->sa.sa_flags & SA_SIGINFO) {
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err |= copy_siginfo_to_user(&frame->info, info);
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if (err)
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goto give_sigsegv;
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}
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/* Create the ucontext. */
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err |= __put_user(0, &frame->uc.uc_flags);
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err |= __put_user(0, &frame->uc.uc_link);
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err |= __put_user(me->sas_ss_sp, &frame->uc.uc_stack.ss_sp);
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err |= __put_user(sas_ss_flags(regs->rsp),
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&frame->uc.uc_stack.ss_flags);
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err |= __put_user(me->sas_ss_size, &frame->uc.uc_stack.ss_size);
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err |= setup_sigcontext(&frame->uc.uc_mcontext, regs, set->sig[0], me);
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err |= __put_user(fp, &frame->uc.uc_mcontext.fpstate);
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if (sizeof(*set) == 16) {
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__put_user(set->sig[0], &frame->uc.uc_sigmask.sig[0]);
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__put_user(set->sig[1], &frame->uc.uc_sigmask.sig[1]);
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} else
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err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
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/* Set up to return from userspace. If provided, use a stub
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already in userspace. */
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/* x86-64 should always use SA_RESTORER. */
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if (ka->sa.sa_flags & SA_RESTORER) {
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err |= __put_user(ka->sa.sa_restorer, &frame->pretcode);
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} else {
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/* could use a vstub here */
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goto give_sigsegv;
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}
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if (err)
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goto give_sigsegv;
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#ifdef DEBUG_SIG
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printk("%d old rip %lx old rsp %lx old rax %lx\n", current->pid,regs->rip,regs->rsp,regs->rax);
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#endif
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/* Set up registers for signal handler */
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{
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struct exec_domain *ed = current_thread_info()->exec_domain;
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if (unlikely(ed && ed->signal_invmap && sig < 32))
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sig = ed->signal_invmap[sig];
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}
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regs->rdi = sig;
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/* In case the signal handler was declared without prototypes */
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regs->rax = 0;
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/* This also works for non SA_SIGINFO handlers because they expect the
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next argument after the signal number on the stack. */
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regs->rsi = (unsigned long)&frame->info;
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regs->rdx = (unsigned long)&frame->uc;
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regs->rip = (unsigned long) ka->sa.sa_handler;
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regs->rsp = (unsigned long)frame;
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set_fs(USER_DS);
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regs->eflags &= ~TF_MASK;
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if (test_thread_flag(TIF_SINGLESTEP))
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ptrace_notify(SIGTRAP);
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#ifdef DEBUG_SIG
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printk("SIG deliver (%s:%d): sp=%p pc=%p ra=%p\n",
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current->comm, current->pid, frame, regs->rip, frame->pretcode);
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#endif
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return 1;
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give_sigsegv:
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force_sigsegv(sig, current);
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return 0;
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}
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/*
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* OK, we're invoking a handler
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*/
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static int
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handle_signal(unsigned long sig, siginfo_t *info, struct k_sigaction *ka,
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sigset_t *oldset, struct pt_regs *regs)
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{
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int ret;
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#ifdef DEBUG_SIG
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printk("handle_signal pid:%d sig:%lu rip:%lx rsp:%lx regs=%p\n",
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current->pid, sig,
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regs->rip, regs->rsp, regs);
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#endif
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/* Are we from a system call? */
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if ((long)regs->orig_rax >= 0) {
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/* If so, check system call restarting.. */
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switch (regs->rax) {
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case -ERESTART_RESTARTBLOCK:
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case -ERESTARTNOHAND:
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regs->rax = -EINTR;
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break;
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case -ERESTARTSYS:
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if (!(ka->sa.sa_flags & SA_RESTART)) {
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regs->rax = -EINTR;
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break;
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}
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/* fallthrough */
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case -ERESTARTNOINTR:
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regs->rax = regs->orig_rax;
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regs->rip -= 2;
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break;
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}
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}
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/*
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* If TF is set due to a debugger (PT_DTRACE), clear the TF
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* flag so that register information in the sigcontext is
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* correct.
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*/
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if (unlikely(regs->eflags & TF_MASK)) {
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if (likely(current->ptrace & PT_DTRACE)) {
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current->ptrace &= ~PT_DTRACE;
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regs->eflags &= ~TF_MASK;
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}
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}
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#ifdef CONFIG_IA32_EMULATION
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if (test_thread_flag(TIF_IA32)) {
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if (ka->sa.sa_flags & SA_SIGINFO)
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ret = ia32_setup_rt_frame(sig, ka, info, oldset, regs);
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else
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ret = ia32_setup_frame(sig, ka, oldset, regs);
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} else
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#endif
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ret = setup_rt_frame(sig, ka, info, oldset, regs);
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if (ret && !(ka->sa.sa_flags & SA_NODEFER)) {
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spin_lock_irq(¤t->sighand->siglock);
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sigorsets(¤t->blocked,¤t->blocked,&ka->sa.sa_mask);
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sigaddset(¤t->blocked,sig);
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recalc_sigpending();
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spin_unlock_irq(¤t->sighand->siglock);
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}
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return ret;
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}
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/*
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* Note that 'init' is a special process: it doesn't get signals it doesn't
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* want to handle. Thus you cannot kill init even with a SIGKILL even by
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* mistake.
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*/
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int do_signal(struct pt_regs *regs, sigset_t *oldset)
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{
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struct k_sigaction ka;
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siginfo_t info;
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int signr;
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/*
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* We want the common case to go fast, which
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* is why we may in certain cases get here from
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* kernel mode. Just return without doing anything
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* if so.
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*/
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if (!user_mode(regs))
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return 1;
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if (try_to_freeze(0))
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goto no_signal;
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if (!oldset)
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oldset = ¤t->blocked;
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signr = get_signal_to_deliver(&info, &ka, regs, NULL);
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if (signr > 0) {
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/* Reenable any watchpoints before delivering the
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* signal to user space. The processor register will
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* have been cleared if the watchpoint triggered
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* inside the kernel.
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*/
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if (current->thread.debugreg7)
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set_debugreg(current->thread.debugreg7, 7);
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/* Whee! Actually deliver the signal. */
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return handle_signal(signr, &info, &ka, oldset, regs);
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}
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no_signal:
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/* Did we come from a system call? */
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if ((long)regs->orig_rax >= 0) {
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/* Restart the system call - no handlers present */
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long res = regs->rax;
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if (res == -ERESTARTNOHAND ||
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res == -ERESTARTSYS ||
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res == -ERESTARTNOINTR) {
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regs->rax = regs->orig_rax;
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regs->rip -= 2;
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}
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if (regs->rax == (unsigned long)-ERESTART_RESTARTBLOCK) {
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regs->rax = test_thread_flag(TIF_IA32) ?
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__NR_ia32_restart_syscall :
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__NR_restart_syscall;
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regs->rip -= 2;
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}
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}
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return 0;
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}
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void do_notify_resume(struct pt_regs *regs, sigset_t *oldset, __u32 thread_info_flags)
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{
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#ifdef DEBUG_SIG
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printk("do_notify_resume flags:%x rip:%lx rsp:%lx caller:%lx pending:%lx\n",
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thread_info_flags, regs->rip, regs->rsp, __builtin_return_address(0),signal_pending(current));
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#endif
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/* Pending single-step? */
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if (thread_info_flags & _TIF_SINGLESTEP) {
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regs->eflags |= TF_MASK;
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clear_thread_flag(TIF_SINGLESTEP);
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}
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/* deal with pending signal delivery */
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if (thread_info_flags & _TIF_SIGPENDING)
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do_signal(regs,oldset);
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}
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void signal_fault(struct pt_regs *regs, void __user *frame, char *where)
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{
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struct task_struct *me = current;
|
|
if (exception_trace)
|
|
printk("%s[%d] bad frame in %s frame:%p rip:%lx rsp:%lx orax:%lx\n",
|
|
me->comm,me->pid,where,frame,regs->rip,regs->rsp,regs->orig_rax);
|
|
|
|
force_sig(SIGSEGV, me);
|
|
}
|