v4.19.13 snapshot.
diff --git a/arch/ia64/kernel/signal.c b/arch/ia64/kernel/signal.c
new file mode 100644
index 0000000..d1234a5
--- /dev/null
+++ b/arch/ia64/kernel/signal.c
@@ -0,0 +1,446 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * 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/errno.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/ptrace.h>
+#include <linux/tracehook.h>
+#include <linux/sched.h>
+#include <linux/signal.h>
+#include <linux/smp.h>
+#include <linux/stddef.h>
+#include <linux/tty.h>
+#include <linux/binfmts.h>
+#include <linux/unistd.h>
+#include <linux/wait.h>
+
+#include <asm/intrinsics.h>
+#include <linux/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 */
+
+#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
+
+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->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);
+
+ err |= __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;
+}
+
+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;
+
+ set_current_blocked(&set);
+
+ 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
+ if (restore_altstack(&sc->sc_stack))
+ goto give_sigsegv;
+ return retval;
+
+ give_sigsegv:
+ clear_siginfo(&si);
+ si.si_signo = SIGSEGV;
+ si.si_errno = 0;
+ si.si_code = SI_KERNEL;
+ si.si_pid = task_pid_vnr(current);
+ si.si_uid = from_kuid_munged(current_user_ns(), 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 = 0;
+
+ 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;
+ err = __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)) {
+ /* 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;
+
+ clear_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 = task_pid_vnr(current);
+ si.si_uid = from_kuid_munged(current_user_ns(), current_uid());
+ si.si_addr = addr;
+ force_sig_info(SIGSEGV, &si, current);
+ return 1;
+}
+
+static long
+setup_frame(struct ksignal *ksig, sigset_t *set, struct sigscratch *scr)
+{
+ extern char __kernel_sigtramp[];
+ unsigned long tramp_addr, new_rbs = 0, new_sp;
+ struct sigframe __user *frame;
+ long err;
+
+ new_sp = scr->pt.r12;
+ tramp_addr = (unsigned long) __kernel_sigtramp;
+ if (ksig->ka.sa.sa_flags & SA_ONSTACK) {
+ int onstack = sas_ss_flags(new_sp);
+
+ if (onstack == 0) {
+ new_sp = current->sas_ss_sp + current->sas_ss_size;
+ /*
+ * 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 = ALIGN(current->sas_ss_sp,
+ sizeof(long));
+ } else if (onstack == SS_ONSTACK) {
+ unsigned long check_sp;
+
+ /*
+ * If we are on the alternate signal stack and would
+ * overflow it, don't. Return an always-bogus address
+ * instead so we will die with SIGSEGV.
+ */
+ check_sp = (new_sp - sizeof(*frame)) & -STACK_ALIGN;
+ if (!likely(on_sig_stack(check_sp)))
+ return force_sigsegv_info(ksig->sig, (void __user *)
+ check_sp);
+ }
+ }
+ frame = (void __user *) ((new_sp - sizeof(*frame)) & -STACK_ALIGN);
+
+ if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
+ return force_sigsegv_info(ksig->sig, frame);
+
+ err = __put_user(ksig->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(ksig->ka.sa.sa_handler, &frame->handler);
+
+ err |= copy_siginfo_to_user(&frame->info, &ksig->info);
+
+ err |= __save_altstack(&frame->sc.sc_stack, scr->pt.r12);
+ err |= setup_sigcontext(&frame->sc, set, scr);
+
+ if (unlikely(err))
+ return force_sigsegv_info(ksig->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, ksig->sig, scr->pt.r12, frame->sc.sc_ip, frame->handler);
+#endif
+ return 0;
+}
+
+static long
+handle_signal (struct ksignal *ksig, struct sigscratch *scr)
+{
+ int ret = setup_frame(ksig, sigmask_to_save(), scr);
+
+ if (!ret)
+ signal_setup_done(ret, ksig, test_thread_flag(TIF_SINGLESTEP));
+
+ return ret;
+}
+
+/*
+ * 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.
+ */
+void
+ia64_do_signal (struct sigscratch *scr, long in_syscall)
+{
+ long restart = in_syscall;
+ long errno = scr->pt.r8;
+ struct ksignal ksig;
+
+ /*
+ * This only loops in the rare cases of handle_signal() failing, in which case we
+ * need to push through a forced SIGSEGV.
+ */
+ while (1) {
+ get_signal(&ksig);
+
+ /*
+ * 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 ((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 (ksig.sig <= 0)
+ break;
+
+ if (unlikely(restart)) {
+ switch (errno) {
+ case ERESTART_RESTARTBLOCK:
+ case ERESTARTNOHAND:
+ scr->pt.r8 = EINTR;
+ /* note: scr->pt.r10 is already -1 */
+ break;
+
+ case ERESTARTSYS:
+ if ((ksig.ka.sa.sa_flags & SA_RESTART) == 0) {
+ scr->pt.r8 = EINTR;
+ /* note: scr->pt.r10 is already -1 */
+ break;
+ }
+ case ERESTARTNOINTR:
+ 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(&ksig, scr))
+ return;
+ }
+
+ /* 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)
+ {
+ /*
+ * 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;
+ }
+ }
+
+ /* if there's no signal to deliver, we just put the saved sigmask
+ * back */
+ restore_saved_sigmask();
+}