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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /arch/ia64/kernel/signal.c
downloadlinux-stericsson-2.6.12-rc2.tar.gz
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'arch/ia64/kernel/signal.c')
-rw-r--r--arch/ia64/kernel/signal.c691
1 files changed, 691 insertions, 0 deletions
diff --git a/arch/ia64/kernel/signal.c b/arch/ia64/kernel/signal.c
new file mode 100644
index 000000000000..6891d86937d9
--- /dev/null
+++ b/arch/ia64/kernel/signal.c
@@ -0,0 +1,691 @@
+/*
+ * 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(&current->sighand->siglock);
+ {
+ oldset = current->blocked;
+ current->blocked = set;
+ recalc_sigpending();
+ }
+ spin_unlock_irq(&current->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;
+ 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(scr->pt.ar_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);
+
+ /* 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... */
+ 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);
+ }
+ }
+ 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))
+ /*
+ * 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(&current->sighand->siglock);
+ {
+ current->blocked = set;
+ recalc_sigpending();
+ }
+ spin_unlock_irq(&current->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(&current->sighand->siglock, flags);
+ current->sighand->action[sig - 1].sa.sa_handler = SIG_DFL;
+ spin_unlock_irqrestore(&current->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;
+
+ if (!(ka->sa.sa_flags & SA_NODEFER)) {
+ spin_lock_irq(&current->sighand->siglock);
+ {
+ sigorsets(&current->blocked, &current->blocked, &ka->sa.sa_mask);
+ sigaddset(&current->blocked, sig);
+ recalc_sigpending();
+ }
+ spin_unlock_irq(&current->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 = &current->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);
+}