| /* |
| * Architecture-specific signal handling support. |
| * |
| * Copyright (C) 1999-2004 Hewlett-Packard Co |
| * David Mosberger-Tang <davidm@hpl.hp.com> |
| * |
| * Derived from i386 and Alpha versions. |
| */ |
| |
| #include <linux/config.h> |
| #include <linux/errno.h> |
| #include <linux/kernel.h> |
| #include <linux/mm.h> |
| #include <linux/ptrace.h> |
| #include <linux/sched.h> |
| #include <linux/signal.h> |
| #include <linux/smp.h> |
| #include <linux/smp_lock.h> |
| #include <linux/stddef.h> |
| #include <linux/tty.h> |
| #include <linux/binfmts.h> |
| #include <linux/unistd.h> |
| #include <linux/wait.h> |
| |
| #include <asm/ia32.h> |
| #include <asm/intrinsics.h> |
| #include <asm/uaccess.h> |
| #include <asm/rse.h> |
| #include <asm/sigcontext.h> |
| |
| #include "sigframe.h" |
| |
| #define DEBUG_SIG 0 |
| #define STACK_ALIGN 16 /* minimal alignment for stack pointer */ |
| #define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP))) |
| |
| #if _NSIG_WORDS > 1 |
| # define PUT_SIGSET(k,u) __copy_to_user((u)->sig, (k)->sig, sizeof(sigset_t)) |
| # define GET_SIGSET(k,u) __copy_from_user((k)->sig, (u)->sig, sizeof(sigset_t)) |
| #else |
| # define PUT_SIGSET(k,u) __put_user((k)->sig[0], &(u)->sig[0]) |
| # define GET_SIGSET(k,u) __get_user((k)->sig[0], &(u)->sig[0]) |
| #endif |
| |
| long |
| ia64_rt_sigsuspend (sigset_t __user *uset, size_t sigsetsize, struct sigscratch *scr) |
| { |
| sigset_t oldset, set; |
| |
| /* XXX: Don't preclude handling different sized sigset_t's. */ |
| if (sigsetsize != sizeof(sigset_t)) |
| return -EINVAL; |
| |
| if (!access_ok(VERIFY_READ, uset, sigsetsize)) |
| return -EFAULT; |
| |
| if (GET_SIGSET(&set, uset)) |
| return -EFAULT; |
| |
| sigdelsetmask(&set, ~_BLOCKABLE); |
| |
| spin_lock_irq(¤t->sighand->siglock); |
| { |
| oldset = current->blocked; |
| current->blocked = set; |
| recalc_sigpending(); |
| } |
| spin_unlock_irq(¤t->sighand->siglock); |
| |
| /* |
| * The return below usually returns to the signal handler. We need to |
| * pre-set the correct error code here to ensure that the right values |
| * get saved in sigcontext by ia64_do_signal. |
| */ |
| scr->pt.r8 = EINTR; |
| scr->pt.r10 = -1; |
| |
| while (1) { |
| current->state = TASK_INTERRUPTIBLE; |
| schedule(); |
| if (ia64_do_signal(&oldset, scr, 1)) |
| return -EINTR; |
| } |
| } |
| |
| asmlinkage long |
| sys_sigaltstack (const stack_t __user *uss, stack_t __user *uoss, long arg2, |
| long arg3, long arg4, long arg5, long arg6, long arg7, |
| struct pt_regs regs) |
| { |
| return do_sigaltstack(uss, uoss, regs.r12); |
| } |
| |
| static long |
| restore_sigcontext (struct sigcontext __user *sc, struct sigscratch *scr) |
| { |
| unsigned long ip, flags, nat, um, cfm, rsc; |
| long err; |
| |
| /* Always make any pending restarted system calls return -EINTR */ |
| current_thread_info()->restart_block.fn = do_no_restart_syscall; |
| |
| /* restore scratch that always needs gets updated during signal delivery: */ |
| err = __get_user(flags, &sc->sc_flags); |
| err |= __get_user(nat, &sc->sc_nat); |
| err |= __get_user(ip, &sc->sc_ip); /* instruction pointer */ |
| err |= __get_user(cfm, &sc->sc_cfm); |
| err |= __get_user(um, &sc->sc_um); /* user mask */ |
| err |= __get_user(rsc, &sc->sc_ar_rsc); |
| err |= __get_user(scr->pt.ar_unat, &sc->sc_ar_unat); |
| err |= __get_user(scr->pt.ar_fpsr, &sc->sc_ar_fpsr); |
| err |= __get_user(scr->pt.ar_pfs, &sc->sc_ar_pfs); |
| err |= __get_user(scr->pt.pr, &sc->sc_pr); /* predicates */ |
| err |= __get_user(scr->pt.b0, &sc->sc_br[0]); /* b0 (rp) */ |
| err |= __get_user(scr->pt.b6, &sc->sc_br[6]); /* b6 */ |
| err |= __copy_from_user(&scr->pt.r1, &sc->sc_gr[1], 8); /* r1 */ |
| err |= __copy_from_user(&scr->pt.r8, &sc->sc_gr[8], 4*8); /* r8-r11 */ |
| err |= __copy_from_user(&scr->pt.r12, &sc->sc_gr[12], 2*8); /* r12-r13 */ |
| err |= __copy_from_user(&scr->pt.r15, &sc->sc_gr[15], 8); /* r15 */ |
| |
| scr->pt.cr_ifs = cfm | (1UL << 63); |
| scr->pt.ar_rsc = rsc | (3 << 2); /* force PL3 */ |
| |
| /* establish new instruction pointer: */ |
| scr->pt.cr_iip = ip & ~0x3UL; |
| ia64_psr(&scr->pt)->ri = ip & 0x3; |
| scr->pt.cr_ipsr = (scr->pt.cr_ipsr & ~IA64_PSR_UM) | (um & IA64_PSR_UM); |
| |
| scr->scratch_unat = ia64_put_scratch_nat_bits(&scr->pt, nat); |
| |
| if (!(flags & IA64_SC_FLAG_IN_SYSCALL)) { |
| /* Restore most scratch-state only when not in syscall. */ |
| err |= __get_user(scr->pt.ar_ccv, &sc->sc_ar_ccv); /* ar.ccv */ |
| err |= __get_user(scr->pt.b7, &sc->sc_br[7]); /* b7 */ |
| err |= __get_user(scr->pt.r14, &sc->sc_gr[14]); /* r14 */ |
| err |= __copy_from_user(&scr->pt.ar_csd, &sc->sc_ar25, 2*8); /* ar.csd & ar.ssd */ |
| err |= __copy_from_user(&scr->pt.r2, &sc->sc_gr[2], 2*8); /* r2-r3 */ |
| err |= __copy_from_user(&scr->pt.r16, &sc->sc_gr[16], 16*8); /* r16-r31 */ |
| } |
| |
| if ((flags & IA64_SC_FLAG_FPH_VALID) != 0) { |
| struct ia64_psr *psr = ia64_psr(&scr->pt); |
| |
| __copy_from_user(current->thread.fph, &sc->sc_fr[32], 96*16); |
| psr->mfh = 0; /* drop signal handler's fph contents... */ |
| preempt_disable(); |
| if (psr->dfh) |
| ia64_drop_fpu(current); |
| else { |
| /* We already own the local fph, otherwise psr->dfh wouldn't be 0. */ |
| __ia64_load_fpu(current->thread.fph); |
| ia64_set_local_fpu_owner(current); |
| } |
| preempt_enable(); |
| } |
| return err; |
| } |
| |
| int |
| copy_siginfo_to_user (siginfo_t __user *to, siginfo_t *from) |
| { |
| if (!access_ok(VERIFY_WRITE, to, sizeof(siginfo_t))) |
| return -EFAULT; |
| if (from->si_code < 0) { |
| if (__copy_to_user(to, from, sizeof(siginfo_t))) |
| return -EFAULT; |
| return 0; |
| } else { |
| int err; |
| |
| /* |
| * If you change siginfo_t structure, please be sure this code is fixed |
| * accordingly. It should never copy any pad contained in the structure |
| * to avoid security leaks, but must copy the generic 3 ints plus the |
| * relevant union member. |
| */ |
| err = __put_user(from->si_signo, &to->si_signo); |
| err |= __put_user(from->si_errno, &to->si_errno); |
| err |= __put_user((short)from->si_code, &to->si_code); |
| switch (from->si_code >> 16) { |
| case __SI_FAULT >> 16: |
| err |= __put_user(from->si_flags, &to->si_flags); |
| err |= __put_user(from->si_isr, &to->si_isr); |
| case __SI_POLL >> 16: |
| err |= __put_user(from->si_addr, &to->si_addr); |
| err |= __put_user(from->si_imm, &to->si_imm); |
| break; |
| case __SI_TIMER >> 16: |
| err |= __put_user(from->si_tid, &to->si_tid); |
| err |= __put_user(from->si_overrun, &to->si_overrun); |
| err |= __put_user(from->si_ptr, &to->si_ptr); |
| break; |
| case __SI_RT >> 16: /* Not generated by the kernel as of now. */ |
| case __SI_MESGQ >> 16: |
| err |= __put_user(from->si_uid, &to->si_uid); |
| err |= __put_user(from->si_pid, &to->si_pid); |
| err |= __put_user(from->si_ptr, &to->si_ptr); |
| break; |
| case __SI_CHLD >> 16: |
| err |= __put_user(from->si_utime, &to->si_utime); |
| err |= __put_user(from->si_stime, &to->si_stime); |
| err |= __put_user(from->si_status, &to->si_status); |
| default: |
| err |= __put_user(from->si_uid, &to->si_uid); |
| err |= __put_user(from->si_pid, &to->si_pid); |
| break; |
| } |
| return err; |
| } |
| } |
| |
| long |
| ia64_rt_sigreturn (struct sigscratch *scr) |
| { |
| extern char ia64_strace_leave_kernel, ia64_leave_kernel; |
| struct sigcontext __user *sc; |
| struct siginfo si; |
| sigset_t set; |
| long retval; |
| |
| sc = &((struct sigframe __user *) (scr->pt.r12 + 16))->sc; |
| |
| /* |
| * When we return to the previously executing context, r8 and r10 have already |
| * been setup the way we want them. Indeed, if the signal wasn't delivered while |
| * in a system call, we must not touch r8 or r10 as otherwise user-level state |
| * could be corrupted. |
| */ |
| retval = (long) &ia64_leave_kernel; |
| if (test_thread_flag(TIF_SYSCALL_TRACE) |
| || test_thread_flag(TIF_SYSCALL_AUDIT)) |
| /* |
| * strace expects to be notified after sigreturn returns even though the |
| * context to which we return may not be in the middle of a syscall. |
| * Thus, the return-value that strace displays for sigreturn is |
| * meaningless. |
| */ |
| retval = (long) &ia64_strace_leave_kernel; |
| |
| if (!access_ok(VERIFY_READ, sc, sizeof(*sc))) |
| goto give_sigsegv; |
| |
| if (GET_SIGSET(&set, &sc->sc_mask)) |
| goto give_sigsegv; |
| |
| sigdelsetmask(&set, ~_BLOCKABLE); |
| |
| spin_lock_irq(¤t->sighand->siglock); |
| { |
| current->blocked = set; |
| recalc_sigpending(); |
| } |
| spin_unlock_irq(¤t->sighand->siglock); |
| |
| if (restore_sigcontext(sc, scr)) |
| goto give_sigsegv; |
| |
| #if DEBUG_SIG |
| printk("SIG return (%s:%d): sp=%lx ip=%lx\n", |
| current->comm, current->pid, scr->pt.r12, scr->pt.cr_iip); |
| #endif |
| /* |
| * It is more difficult to avoid calling this function than to |
| * call it and ignore errors. |
| */ |
| do_sigaltstack(&sc->sc_stack, NULL, scr->pt.r12); |
| return retval; |
| |
| give_sigsegv: |
| si.si_signo = SIGSEGV; |
| si.si_errno = 0; |
| si.si_code = SI_KERNEL; |
| si.si_pid = current->pid; |
| si.si_uid = current->uid; |
| si.si_addr = sc; |
| force_sig_info(SIGSEGV, &si, current); |
| return retval; |
| } |
| |
| /* |
| * This does just the minimum required setup of sigcontext. |
| * Specifically, it only installs data that is either not knowable at |
| * the user-level or that gets modified before execution in the |
| * trampoline starts. Everything else is done at the user-level. |
| */ |
| static long |
| setup_sigcontext (struct sigcontext __user *sc, sigset_t *mask, struct sigscratch *scr) |
| { |
| unsigned long flags = 0, ifs, cfm, nat; |
| long err; |
| |
| ifs = scr->pt.cr_ifs; |
| |
| if (on_sig_stack((unsigned long) sc)) |
| flags |= IA64_SC_FLAG_ONSTACK; |
| if ((ifs & (1UL << 63)) == 0) |
| /* if cr_ifs doesn't have the valid bit set, we got here through a syscall */ |
| flags |= IA64_SC_FLAG_IN_SYSCALL; |
| cfm = ifs & ((1UL << 38) - 1); |
| ia64_flush_fph(current); |
| if ((current->thread.flags & IA64_THREAD_FPH_VALID)) { |
| flags |= IA64_SC_FLAG_FPH_VALID; |
| __copy_to_user(&sc->sc_fr[32], current->thread.fph, 96*16); |
| } |
| |
| nat = ia64_get_scratch_nat_bits(&scr->pt, scr->scratch_unat); |
| |
| err = __put_user(flags, &sc->sc_flags); |
| err |= __put_user(nat, &sc->sc_nat); |
| err |= PUT_SIGSET(mask, &sc->sc_mask); |
| err |= __put_user(cfm, &sc->sc_cfm); |
| err |= __put_user(scr->pt.cr_ipsr & IA64_PSR_UM, &sc->sc_um); |
| err |= __put_user(scr->pt.ar_rsc, &sc->sc_ar_rsc); |
| err |= __put_user(scr->pt.ar_unat, &sc->sc_ar_unat); /* ar.unat */ |
| err |= __put_user(scr->pt.ar_fpsr, &sc->sc_ar_fpsr); /* ar.fpsr */ |
| err |= __put_user(scr->pt.ar_pfs, &sc->sc_ar_pfs); |
| err |= __put_user(scr->pt.pr, &sc->sc_pr); /* predicates */ |
| err |= __put_user(scr->pt.b0, &sc->sc_br[0]); /* b0 (rp) */ |
| err |= __put_user(scr->pt.b6, &sc->sc_br[6]); /* b6 */ |
| err |= __copy_to_user(&sc->sc_gr[1], &scr->pt.r1, 8); /* r1 */ |
| err |= __copy_to_user(&sc->sc_gr[8], &scr->pt.r8, 4*8); /* r8-r11 */ |
| err |= __copy_to_user(&sc->sc_gr[12], &scr->pt.r12, 2*8); /* r12-r13 */ |
| err |= __copy_to_user(&sc->sc_gr[15], &scr->pt.r15, 8); /* r15 */ |
| err |= __put_user(scr->pt.cr_iip + ia64_psr(&scr->pt)->ri, &sc->sc_ip); |
| |
| if (flags & IA64_SC_FLAG_IN_SYSCALL) { |
| /* Clear scratch registers if the signal interrupted a system call. */ |
| err |= __put_user(0, &sc->sc_ar_ccv); /* ar.ccv */ |
| err |= __put_user(0, &sc->sc_br[7]); /* b7 */ |
| err |= __put_user(0, &sc->sc_gr[14]); /* r14 */ |
| err |= __clear_user(&sc->sc_ar25, 2*8); /* ar.csd & ar.ssd */ |
| err |= __clear_user(&sc->sc_gr[2], 2*8); /* r2-r3 */ |
| err |= __clear_user(&sc->sc_gr[16], 16*8); /* r16-r31 */ |
| } else { |
| /* Copy scratch regs to sigcontext if the signal didn't interrupt a syscall. */ |
| err |= __put_user(scr->pt.ar_ccv, &sc->sc_ar_ccv); /* ar.ccv */ |
| err |= __put_user(scr->pt.b7, &sc->sc_br[7]); /* b7 */ |
| err |= __put_user(scr->pt.r14, &sc->sc_gr[14]); /* r14 */ |
| err |= __copy_to_user(&sc->sc_ar25, &scr->pt.ar_csd, 2*8); /* ar.csd & ar.ssd */ |
| err |= __copy_to_user(&sc->sc_gr[2], &scr->pt.r2, 2*8); /* r2-r3 */ |
| err |= __copy_to_user(&sc->sc_gr[16], &scr->pt.r16, 16*8); /* r16-r31 */ |
| } |
| return err; |
| } |
| |
| /* |
| * Check whether the register-backing store is already on the signal stack. |
| */ |
| static inline int |
| rbs_on_sig_stack (unsigned long bsp) |
| { |
| return (bsp - current->sas_ss_sp < current->sas_ss_size); |
| } |
| |
| static long |
| force_sigsegv_info (int sig, void __user *addr) |
| { |
| unsigned long flags; |
| struct siginfo si; |
| |
| if (sig == SIGSEGV) { |
| /* |
| * Acquiring siglock around the sa_handler-update is almost |
| * certainly overkill, but this isn't a |
| * performance-critical path and I'd rather play it safe |
| * here than having to debug a nasty race if and when |
| * something changes in kernel/signal.c that would make it |
| * no longer safe to modify sa_handler without holding the |
| * lock. |
| */ |
| spin_lock_irqsave(¤t->sighand->siglock, flags); |
| current->sighand->action[sig - 1].sa.sa_handler = SIG_DFL; |
| spin_unlock_irqrestore(¤t->sighand->siglock, flags); |
| } |
| si.si_signo = SIGSEGV; |
| si.si_errno = 0; |
| si.si_code = SI_KERNEL; |
| si.si_pid = current->pid; |
| si.si_uid = current->uid; |
| si.si_addr = addr; |
| force_sig_info(SIGSEGV, &si, current); |
| return 0; |
| } |
| |
| static long |
| setup_frame (int sig, struct k_sigaction *ka, siginfo_t *info, sigset_t *set, |
| struct sigscratch *scr) |
| { |
| extern char __kernel_sigtramp[]; |
| unsigned long tramp_addr, new_rbs = 0; |
| struct sigframe __user *frame; |
| long err; |
| |
| frame = (void __user *) scr->pt.r12; |
| tramp_addr = (unsigned long) __kernel_sigtramp; |
| if ((ka->sa.sa_flags & SA_ONSTACK) && sas_ss_flags((unsigned long) frame) == 0) { |
| frame = (void __user *) ((current->sas_ss_sp + current->sas_ss_size) |
| & ~(STACK_ALIGN - 1)); |
| /* |
| * We need to check for the register stack being on the signal stack |
| * separately, because it's switched separately (memory stack is switched |
| * in the kernel, register stack is switched in the signal trampoline). |
| */ |
| if (!rbs_on_sig_stack(scr->pt.ar_bspstore)) |
| new_rbs = (current->sas_ss_sp + sizeof(long) - 1) & ~(sizeof(long) - 1); |
| } |
| frame = (void __user *) frame - ((sizeof(*frame) + STACK_ALIGN - 1) & ~(STACK_ALIGN - 1)); |
| |
| if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) |
| return force_sigsegv_info(sig, frame); |
| |
| err = __put_user(sig, &frame->arg0); |
| err |= __put_user(&frame->info, &frame->arg1); |
| err |= __put_user(&frame->sc, &frame->arg2); |
| err |= __put_user(new_rbs, &frame->sc.sc_rbs_base); |
| err |= __put_user(0, &frame->sc.sc_loadrs); /* initialize to zero */ |
| err |= __put_user(ka->sa.sa_handler, &frame->handler); |
| |
| err |= copy_siginfo_to_user(&frame->info, info); |
| |
| err |= __put_user(current->sas_ss_sp, &frame->sc.sc_stack.ss_sp); |
| err |= __put_user(current->sas_ss_size, &frame->sc.sc_stack.ss_size); |
| err |= __put_user(sas_ss_flags(scr->pt.r12), &frame->sc.sc_stack.ss_flags); |
| err |= setup_sigcontext(&frame->sc, set, scr); |
| |
| if (unlikely(err)) |
| return force_sigsegv_info(sig, frame); |
| |
| scr->pt.r12 = (unsigned long) frame - 16; /* new stack pointer */ |
| scr->pt.ar_fpsr = FPSR_DEFAULT; /* reset fpsr for signal handler */ |
| scr->pt.cr_iip = tramp_addr; |
| ia64_psr(&scr->pt)->ri = 0; /* start executing in first slot */ |
| ia64_psr(&scr->pt)->be = 0; /* force little-endian byte-order */ |
| /* |
| * Force the interruption function mask to zero. This has no effect when a |
| * system-call got interrupted by a signal (since, in that case, scr->pt_cr_ifs is |
| * ignored), but it has the desirable effect of making it possible to deliver a |
| * signal with an incomplete register frame (which happens when a mandatory RSE |
| * load faults). Furthermore, it has no negative effect on the getting the user's |
| * dirty partition preserved, because that's governed by scr->pt.loadrs. |
| */ |
| scr->pt.cr_ifs = (1UL << 63); |
| |
| /* |
| * Note: this affects only the NaT bits of the scratch regs (the ones saved in |
| * pt_regs), which is exactly what we want. |
| */ |
| scr->scratch_unat = 0; /* ensure NaT bits of r12 is clear */ |
| |
| #if DEBUG_SIG |
| printk("SIG deliver (%s:%d): sig=%d sp=%lx ip=%lx handler=%p\n", |
| current->comm, current->pid, sig, scr->pt.r12, frame->sc.sc_ip, frame->handler); |
| #endif |
| return 1; |
| } |
| |
| static long |
| handle_signal (unsigned long sig, struct k_sigaction *ka, siginfo_t *info, sigset_t *oldset, |
| struct sigscratch *scr) |
| { |
| if (IS_IA32_PROCESS(&scr->pt)) { |
| /* send signal to IA-32 process */ |
| if (!ia32_setup_frame1(sig, ka, info, oldset, &scr->pt)) |
| return 0; |
| } else |
| /* send signal to IA-64 process */ |
| if (!setup_frame(sig, ka, info, oldset, scr)) |
| return 0; |
| |
| spin_lock_irq(¤t->sighand->siglock); |
| sigorsets(¤t->blocked, ¤t->blocked, &ka->sa.sa_mask); |
| if (!(ka->sa.sa_flags & SA_NODEFER)) |
| sigaddset(¤t->blocked, sig); |
| recalc_sigpending(); |
| spin_unlock_irq(¤t->sighand->siglock); |
| return 1; |
| } |
| |
| /* |
| * 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. |
| */ |
| long |
| ia64_do_signal (sigset_t *oldset, struct sigscratch *scr, long in_syscall) |
| { |
| struct k_sigaction ka; |
| siginfo_t info; |
| long restart = in_syscall; |
| long errno = scr->pt.r8; |
| # define ERR_CODE(c) (IS_IA32_PROCESS(&scr->pt) ? -(c) : (c)) |
| |
| /* |
| * In the ia64_leave_kernel code path, 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 (!user_mode(&scr->pt)) |
| return 0; |
| |
| if (!oldset) |
| oldset = ¤t->blocked; |
| |
| /* |
| * This only loops in the rare cases of handle_signal() failing, in which case we |
| * need to push through a forced SIGSEGV. |
| */ |
| while (1) { |
| int signr = get_signal_to_deliver(&info, &ka, &scr->pt, NULL); |
| |
| /* |
| * get_signal_to_deliver() may have run a debugger (via notify_parent()) |
| * and the debugger may have modified the state (e.g., to arrange for an |
| * inferior call), thus it's important to check for restarting _after_ |
| * get_signal_to_deliver(). |
| */ |
| if (IS_IA32_PROCESS(&scr->pt)) { |
| if (in_syscall) { |
| if (errno >= 0) |
| restart = 0; |
| else |
| errno = -errno; |
| } |
| } else if ((long) scr->pt.r10 != -1) |
| /* |
| * A system calls has to be restarted only if one of the error codes |
| * ERESTARTNOHAND, ERESTARTSYS, or ERESTARTNOINTR is returned. If r10 |
| * isn't -1 then r8 doesn't hold an error code and we don't need to |
| * restart the syscall, so we can clear the "restart" flag here. |
| */ |
| restart = 0; |
| |
| if (signr <= 0) |
| break; |
| |
| if (unlikely(restart)) { |
| switch (errno) { |
| case ERESTART_RESTARTBLOCK: |
| case ERESTARTNOHAND: |
| scr->pt.r8 = ERR_CODE(EINTR); |
| /* note: scr->pt.r10 is already -1 */ |
| break; |
| |
| case ERESTARTSYS: |
| if ((ka.sa.sa_flags & SA_RESTART) == 0) { |
| scr->pt.r8 = ERR_CODE(EINTR); |
| /* note: scr->pt.r10 is already -1 */ |
| break; |
| } |
| case ERESTARTNOINTR: |
| if (IS_IA32_PROCESS(&scr->pt)) { |
| scr->pt.r8 = scr->pt.r1; |
| scr->pt.cr_iip -= 2; |
| } else |
| ia64_decrement_ip(&scr->pt); |
| restart = 0; /* don't restart twice if handle_signal() fails... */ |
| } |
| } |
| |
| /* |
| * Whee! Actually deliver the signal. If the delivery failed, we need to |
| * continue to iterate in this loop so we can deliver the SIGSEGV... |
| */ |
| if (handle_signal(signr, &ka, &info, oldset, scr)) |
| return 1; |
| } |
| |
| /* Did we come from a system call? */ |
| if (restart) { |
| /* Restart the system call - no handlers present */ |
| if (errno == ERESTARTNOHAND || errno == ERESTARTSYS || errno == ERESTARTNOINTR |
| || errno == ERESTART_RESTARTBLOCK) |
| { |
| if (IS_IA32_PROCESS(&scr->pt)) { |
| scr->pt.r8 = scr->pt.r1; |
| scr->pt.cr_iip -= 2; |
| if (errno == ERESTART_RESTARTBLOCK) |
| scr->pt.r8 = 0; /* x86 version of __NR_restart_syscall */ |
| } else { |
| /* |
| * Note: the syscall number is in r15 which is saved in |
| * pt_regs so all we need to do here is adjust ip so that |
| * the "break" instruction gets re-executed. |
| */ |
| ia64_decrement_ip(&scr->pt); |
| if (errno == ERESTART_RESTARTBLOCK) |
| scr->pt.r15 = __NR_restart_syscall; |
| } |
| } |
| } |
| return 0; |
| } |
| |
| /* Set a delayed signal that was detected in MCA/INIT/NMI/PMI context where it |
| * could not be delivered. It is important that the target process is not |
| * allowed to do any more work in user space. Possible cases for the target |
| * process: |
| * |
| * - It is sleeping and will wake up soon. Store the data in the current task, |
| * the signal will be sent when the current task returns from the next |
| * interrupt. |
| * |
| * - It is running in user context. Store the data in the current task, the |
| * signal will be sent when the current task returns from the next interrupt. |
| * |
| * - It is running in kernel context on this or another cpu and will return to |
| * user context. Store the data in the target task, the signal will be sent |
| * to itself when the target task returns to user space. |
| * |
| * - It is running in kernel context on this cpu and will sleep before |
| * returning to user context. Because this is also the current task, the |
| * signal will not get delivered and the task could sleep indefinitely. |
| * Store the data in the idle task for this cpu, the signal will be sent |
| * after the idle task processes its next interrupt. |
| * |
| * To cover all cases, store the data in the target task, the current task and |
| * the idle task on this cpu. Whatever happens, the signal will be delivered |
| * to the target task before it can do any useful user space work. Multiple |
| * deliveries have no unwanted side effects. |
| * |
| * Note: This code is executed in MCA/INIT/NMI/PMI context, with interrupts |
| * disabled. It must not take any locks nor use kernel structures or services |
| * that require locks. |
| */ |
| |
| /* To ensure that we get the right pid, check its start time. To avoid extra |
| * include files in thread_info.h, convert the task start_time to unsigned long, |
| * giving us a cycle time of > 580 years. |
| */ |
| static inline unsigned long |
| start_time_ul(const struct task_struct *t) |
| { |
| return t->start_time.tv_sec * NSEC_PER_SEC + t->start_time.tv_nsec; |
| } |
| |
| void |
| set_sigdelayed(pid_t pid, int signo, int code, void __user *addr) |
| { |
| struct task_struct *t; |
| unsigned long start_time = 0; |
| int i; |
| |
| for (i = 1; i <= 3; ++i) { |
| switch (i) { |
| case 1: |
| t = find_task_by_pid(pid); |
| if (t) |
| start_time = start_time_ul(t); |
| break; |
| case 2: |
| t = current; |
| break; |
| default: |
| t = idle_task(smp_processor_id()); |
| break; |
| } |
| |
| if (!t) |
| return; |
| t->thread_info->sigdelayed.signo = signo; |
| t->thread_info->sigdelayed.code = code; |
| t->thread_info->sigdelayed.addr = addr; |
| t->thread_info->sigdelayed.start_time = start_time; |
| t->thread_info->sigdelayed.pid = pid; |
| wmb(); |
| set_tsk_thread_flag(t, TIF_SIGDELAYED); |
| } |
| } |
| |
| /* Called from entry.S when it detects TIF_SIGDELAYED, a delayed signal that |
| * was detected in MCA/INIT/NMI/PMI context where it could not be delivered. |
| */ |
| |
| void |
| do_sigdelayed(void) |
| { |
| struct siginfo siginfo; |
| pid_t pid; |
| struct task_struct *t; |
| |
| clear_thread_flag(TIF_SIGDELAYED); |
| memset(&siginfo, 0, sizeof(siginfo)); |
| siginfo.si_signo = current_thread_info()->sigdelayed.signo; |
| siginfo.si_code = current_thread_info()->sigdelayed.code; |
| siginfo.si_addr = current_thread_info()->sigdelayed.addr; |
| pid = current_thread_info()->sigdelayed.pid; |
| t = find_task_by_pid(pid); |
| if (!t) |
| return; |
| if (current_thread_info()->sigdelayed.start_time != start_time_ul(t)) |
| return; |
| force_sig_info(siginfo.si_signo, &siginfo, t); |
| } |