You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
488 lines
12 KiB
488 lines
12 KiB
/*
|
|
* linux/arch/x86_64/kernel/signal.c
|
|
*
|
|
* Copyright (C) 1991, 1992 Linus Torvalds
|
|
* Copyright (C) 2000, 2001, 2002 Andi Kleen SuSE Labs
|
|
*
|
|
* 1997-11-28 Modified for POSIX.1b signals by Richard Henderson
|
|
* 2000-06-20 Pentium III FXSR, SSE support by Gareth Hughes
|
|
* 2000-2002 x86-64 support by Andi Kleen
|
|
*
|
|
* $Id: signal.c,v 1.18 2001/10/17 22:30:37 ak Exp $
|
|
*/
|
|
|
|
#include <linux/sched.h>
|
|
#include <linux/mm.h>
|
|
#include <linux/smp.h>
|
|
#include <linux/smp_lock.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/signal.h>
|
|
#include <linux/errno.h>
|
|
#include <linux/wait.h>
|
|
#include <linux/ptrace.h>
|
|
#include <linux/unistd.h>
|
|
#include <linux/stddef.h>
|
|
#include <linux/personality.h>
|
|
#include <linux/compiler.h>
|
|
#include <asm/ucontext.h>
|
|
#include <asm/uaccess.h>
|
|
#include <asm/i387.h>
|
|
#include <asm/proto.h>
|
|
|
|
/* #define DEBUG_SIG 1 */
|
|
|
|
#define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
|
|
|
|
void ia32_setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
|
|
sigset_t *set, struct pt_regs * regs);
|
|
void ia32_setup_frame(int sig, struct k_sigaction *ka,
|
|
sigset_t *set, struct pt_regs * regs);
|
|
|
|
asmlinkage long
|
|
sys_rt_sigsuspend(sigset_t __user *unewset, size_t sigsetsize, struct pt_regs *regs)
|
|
{
|
|
sigset_t saveset, newset;
|
|
|
|
/* XXX: Don't preclude handling different sized sigset_t's. */
|
|
if (sigsetsize != sizeof(sigset_t))
|
|
return -EINVAL;
|
|
|
|
if (copy_from_user(&newset, unewset, sizeof(newset)))
|
|
return -EFAULT;
|
|
sigdelsetmask(&newset, ~_BLOCKABLE);
|
|
|
|
spin_lock_irq(¤t->sighand->siglock);
|
|
saveset = current->blocked;
|
|
current->blocked = newset;
|
|
recalc_sigpending();
|
|
spin_unlock_irq(¤t->sighand->siglock);
|
|
#ifdef DEBUG_SIG
|
|
printk("rt_sigsuspend savset(%lx) newset(%lx) regs(%p) rip(%lx)\n",
|
|
saveset, newset, regs, regs->rip);
|
|
#endif
|
|
regs->rax = -EINTR;
|
|
while (1) {
|
|
current->state = TASK_INTERRUPTIBLE;
|
|
schedule();
|
|
if (do_signal(regs, &saveset))
|
|
return -EINTR;
|
|
}
|
|
}
|
|
|
|
asmlinkage long
|
|
sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss,
|
|
struct pt_regs *regs)
|
|
{
|
|
return do_sigaltstack(uss, uoss, regs->rsp);
|
|
}
|
|
|
|
|
|
/*
|
|
* Do a signal return; undo the signal stack.
|
|
*/
|
|
|
|
struct rt_sigframe
|
|
{
|
|
char __user *pretcode;
|
|
struct ucontext uc;
|
|
struct siginfo info;
|
|
};
|
|
|
|
static int
|
|
restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc, unsigned long *prax)
|
|
{
|
|
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)
|
|
|
|
COPY(rdi); COPY(rsi); COPY(rbp); COPY(rsp); COPY(rbx);
|
|
COPY(rdx); COPY(rcx); COPY(rip);
|
|
COPY(r8);
|
|
COPY(r9);
|
|
COPY(r10);
|
|
COPY(r11);
|
|
COPY(r12);
|
|
COPY(r13);
|
|
COPY(r14);
|
|
COPY(r15);
|
|
|
|
{
|
|
unsigned int tmpflags;
|
|
err |= __get_user(tmpflags, &sc->eflags);
|
|
regs->eflags = (regs->eflags & ~0x40DD5) | (tmpflags & 0x40DD5);
|
|
regs->orig_rax = -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(*prax, &sc->rax);
|
|
return err;
|
|
|
|
badframe:
|
|
return 1;
|
|
}
|
|
|
|
asmlinkage long sys_rt_sigreturn(struct pt_regs *regs)
|
|
{
|
|
struct rt_sigframe __user *frame;
|
|
sigset_t set;
|
|
unsigned long eax;
|
|
|
|
frame = (struct rt_sigframe __user *)(regs->rsp - 8);
|
|
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;
|
|
|
|
#ifdef DEBUG_SIG
|
|
printk("%d sigreturn rip:%lx rsp:%lx frame:%p rax:%lx\n",current->pid,regs.rip,regs.rsp,frame,eax);
|
|
#endif
|
|
|
|
if (do_sigaltstack(&frame->uc.uc_stack, NULL, regs->rsp) == -EFAULT)
|
|
goto badframe;
|
|
|
|
return eax;
|
|
|
|
badframe:
|
|
signal_fault(regs,frame,"sigreturn");
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Set up a signal frame.
|
|
*/
|
|
|
|
static inline int
|
|
setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs, unsigned long mask, struct task_struct *me)
|
|
{
|
|
int err = 0;
|
|
|
|
err |= __put_user(0, &sc->gs);
|
|
err |= __put_user(0, &sc->fs);
|
|
|
|
err |= __put_user(regs->rdi, &sc->rdi);
|
|
err |= __put_user(regs->rsi, &sc->rsi);
|
|
err |= __put_user(regs->rbp, &sc->rbp);
|
|
err |= __put_user(regs->rsp, &sc->rsp);
|
|
err |= __put_user(regs->rbx, &sc->rbx);
|
|
err |= __put_user(regs->rdx, &sc->rdx);
|
|
err |= __put_user(regs->rcx, &sc->rcx);
|
|
err |= __put_user(regs->rax, &sc->rax);
|
|
err |= __put_user(regs->r8, &sc->r8);
|
|
err |= __put_user(regs->r9, &sc->r9);
|
|
err |= __put_user(regs->r10, &sc->r10);
|
|
err |= __put_user(regs->r11, &sc->r11);
|
|
err |= __put_user(regs->r12, &sc->r12);
|
|
err |= __put_user(regs->r13, &sc->r13);
|
|
err |= __put_user(regs->r14, &sc->r14);
|
|
err |= __put_user(regs->r15, &sc->r15);
|
|
err |= __put_user(me->thread.trap_no, &sc->trapno);
|
|
err |= __put_user(me->thread.error_code, &sc->err);
|
|
err |= __put_user(regs->rip, &sc->rip);
|
|
err |= __put_user(regs->eflags, &sc->eflags);
|
|
err |= __put_user(mask, &sc->oldmask);
|
|
err |= __put_user(me->thread.cr2, &sc->cr2);
|
|
|
|
return err;
|
|
}
|
|
|
|
/*
|
|
* Determine which stack to use..
|
|
*/
|
|
|
|
static void __user *
|
|
get_stack(struct k_sigaction *ka, struct pt_regs *regs, unsigned long size)
|
|
{
|
|
unsigned long rsp;
|
|
|
|
/* Default to using normal stack - redzone*/
|
|
rsp = regs->rsp - 128;
|
|
|
|
/* This is the X/Open sanctioned signal stack switching. */
|
|
/* RED-PEN: redzone on that stack? */
|
|
if (ka->sa.sa_flags & SA_ONSTACK) {
|
|
if (sas_ss_flags(rsp) == 0)
|
|
rsp = current->sas_ss_sp + current->sas_ss_size;
|
|
}
|
|
|
|
return (void __user *)round_down(rsp - size, 16);
|
|
}
|
|
|
|
static void setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
|
|
sigset_t *set, struct pt_regs * regs)
|
|
{
|
|
struct rt_sigframe __user *frame;
|
|
struct _fpstate __user *fp = NULL;
|
|
int err = 0;
|
|
struct task_struct *me = current;
|
|
|
|
if (used_math()) {
|
|
fp = get_stack(ka, regs, sizeof(struct _fpstate));
|
|
frame = (void __user *)round_down(
|
|
(unsigned long)fp - sizeof(struct rt_sigframe), 16) - 8;
|
|
|
|
if (!access_ok(VERIFY_WRITE, fp, sizeof(struct _fpstate)))
|
|
goto give_sigsegv;
|
|
|
|
if (save_i387(fp) < 0)
|
|
err |= -1;
|
|
} else
|
|
frame = get_stack(ka, regs, sizeof(struct rt_sigframe)) - 8;
|
|
|
|
if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
|
|
goto give_sigsegv;
|
|
|
|
if (ka->sa.sa_flags & SA_SIGINFO) {
|
|
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(me->sas_ss_sp, &frame->uc.uc_stack.ss_sp);
|
|
err |= __put_user(sas_ss_flags(regs->rsp),
|
|
&frame->uc.uc_stack.ss_flags);
|
|
err |= __put_user(me->sas_ss_size, &frame->uc.uc_stack.ss_size);
|
|
err |= setup_sigcontext(&frame->uc.uc_mcontext, regs, set->sig[0], me);
|
|
err |= __put_user(fp, &frame->uc.uc_mcontext.fpstate);
|
|
if (sizeof(*set) == 16) {
|
|
__put_user(set->sig[0], &frame->uc.uc_sigmask.sig[0]);
|
|
__put_user(set->sig[1], &frame->uc.uc_sigmask.sig[1]);
|
|
} else
|
|
err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
|
|
|
|
/* Set up to return from userspace. If provided, use a stub
|
|
already in userspace. */
|
|
/* x86-64 should always use SA_RESTORER. */
|
|
if (ka->sa.sa_flags & SA_RESTORER) {
|
|
err |= __put_user(ka->sa.sa_restorer, &frame->pretcode);
|
|
} else {
|
|
/* could use a vstub here */
|
|
goto give_sigsegv;
|
|
}
|
|
|
|
if (err)
|
|
goto give_sigsegv;
|
|
|
|
#ifdef DEBUG_SIG
|
|
printk("%d old rip %lx old rsp %lx old rax %lx\n", current->pid,regs->rip,regs->rsp,regs->rax);
|
|
#endif
|
|
|
|
/* Set up registers for signal handler */
|
|
{
|
|
struct exec_domain *ed = current_thread_info()->exec_domain;
|
|
if (unlikely(ed && ed->signal_invmap && sig < 32))
|
|
sig = ed->signal_invmap[sig];
|
|
}
|
|
regs->rdi = sig;
|
|
/* In case the signal handler was declared without prototypes */
|
|
regs->rax = 0;
|
|
|
|
/* This also works for non SA_SIGINFO handlers because they expect the
|
|
next argument after the signal number on the stack. */
|
|
regs->rsi = (unsigned long)&frame->info;
|
|
regs->rdx = (unsigned long)&frame->uc;
|
|
regs->rip = (unsigned long) ka->sa.sa_handler;
|
|
|
|
regs->rsp = (unsigned long)frame;
|
|
|
|
set_fs(USER_DS);
|
|
regs->eflags &= ~TF_MASK;
|
|
if (test_thread_flag(TIF_SINGLESTEP))
|
|
ptrace_notify(SIGTRAP);
|
|
#ifdef DEBUG_SIG
|
|
printk("SIG deliver (%s:%d): sp=%p pc=%p ra=%p\n",
|
|
current->comm, current->pid, frame, regs->rip, frame->pretcode);
|
|
#endif
|
|
|
|
return;
|
|
|
|
give_sigsegv:
|
|
force_sigsegv(sig, current);
|
|
}
|
|
|
|
/*
|
|
* OK, we're invoking a handler
|
|
*/
|
|
|
|
static void
|
|
handle_signal(unsigned long sig, siginfo_t *info, struct k_sigaction *ka,
|
|
sigset_t *oldset, struct pt_regs *regs)
|
|
{
|
|
#ifdef DEBUG_SIG
|
|
printk("handle_signal pid:%d sig:%lu rip:%lx rsp:%lx regs=%p\n",
|
|
current->pid, sig,
|
|
regs->rip, regs->rsp, regs);
|
|
#endif
|
|
|
|
/* Are we from a system call? */
|
|
if ((long)regs->orig_rax >= 0) {
|
|
/* If so, check system call restarting.. */
|
|
switch (regs->rax) {
|
|
case -ERESTART_RESTARTBLOCK:
|
|
case -ERESTARTNOHAND:
|
|
regs->rax = -EINTR;
|
|
break;
|
|
|
|
case -ERESTARTSYS:
|
|
if (!(ka->sa.sa_flags & SA_RESTART)) {
|
|
regs->rax = -EINTR;
|
|
break;
|
|
}
|
|
/* fallthrough */
|
|
case -ERESTARTNOINTR:
|
|
regs->rax = regs->orig_rax;
|
|
regs->rip -= 2;
|
|
break;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* 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)) {
|
|
if (likely(current->ptrace & PT_DTRACE)) {
|
|
current->ptrace &= ~PT_DTRACE;
|
|
regs->eflags &= ~TF_MASK;
|
|
}
|
|
}
|
|
|
|
#ifdef CONFIG_IA32_EMULATION
|
|
if (test_thread_flag(TIF_IA32)) {
|
|
if (ka->sa.sa_flags & SA_SIGINFO)
|
|
ia32_setup_rt_frame(sig, ka, info, oldset, regs);
|
|
else
|
|
ia32_setup_frame(sig, ka, oldset, regs);
|
|
} else
|
|
#endif
|
|
setup_rt_frame(sig, ka, info, oldset, regs);
|
|
|
|
if (!(ka->sa.sa_flags & SA_NODEFER)) {
|
|
spin_lock_irq(¤t->sighand->siglock);
|
|
sigorsets(¤t->blocked,¤t->blocked,&ka->sa.sa_mask);
|
|
sigaddset(¤t->blocked,sig);
|
|
recalc_sigpending();
|
|
spin_unlock_irq(¤t->sighand->siglock);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Note that 'init' is a special process: it doesn't get signals it doesn't
|
|
* want to handle. Thus you cannot kill init even with a SIGKILL even by
|
|
* mistake.
|
|
*/
|
|
int do_signal(struct pt_regs *regs, sigset_t *oldset)
|
|
{
|
|
struct k_sigaction ka;
|
|
siginfo_t info;
|
|
int signr;
|
|
|
|
/*
|
|
* We want the common case to go fast, which
|
|
* is why we may in certain cases get here from
|
|
* kernel mode. Just return without doing anything
|
|
* if so.
|
|
*/
|
|
if ((regs->cs & 3) != 3)
|
|
return 1;
|
|
|
|
if (try_to_freeze(0))
|
|
goto no_signal;
|
|
|
|
if (!oldset)
|
|
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 (current->thread.debugreg7)
|
|
asm volatile("movq %0,%%db7" : : "r" (current->thread.debugreg7));
|
|
|
|
/* Whee! Actually deliver the signal. */
|
|
handle_signal(signr, &info, &ka, oldset, regs);
|
|
return 1;
|
|
}
|
|
|
|
no_signal:
|
|
/* Did we come from a system call? */
|
|
if ((long)regs->orig_rax >= 0) {
|
|
/* Restart the system call - no handlers present */
|
|
long res = regs->rax;
|
|
if (res == -ERESTARTNOHAND ||
|
|
res == -ERESTARTSYS ||
|
|
res == -ERESTARTNOINTR) {
|
|
regs->rax = regs->orig_rax;
|
|
regs->rip -= 2;
|
|
}
|
|
if (regs->rax == (unsigned long)-ERESTART_RESTARTBLOCK) {
|
|
regs->rax = __NR_restart_syscall;
|
|
regs->rip -= 2;
|
|
}
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
void do_notify_resume(struct pt_regs *regs, sigset_t *oldset, __u32 thread_info_flags)
|
|
{
|
|
#ifdef DEBUG_SIG
|
|
printk("do_notify_resume flags:%x rip:%lx rsp:%lx caller:%lx pending:%lx\n",
|
|
thread_info_flags, regs->rip, regs->rsp, __builtin_return_address(0),signal_pending(current));
|
|
#endif
|
|
|
|
/* 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)
|
|
do_signal(regs,oldset);
|
|
}
|
|
|
|
void signal_fault(struct pt_regs *regs, void __user *frame, char *where)
|
|
{
|
|
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);
|
|
}
|
|
|