| /* |
| * 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); |
| } |