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https://github.com/AuxXxilium/linux_dsm_epyc7002.git
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96d4f267e4
Nobody has actually used the type (VERIFY_READ vs VERIFY_WRITE) argument
of the user address range verification function since we got rid of the
old racy i386-only code to walk page tables by hand.
It existed because the original 80386 would not honor the write protect
bit when in kernel mode, so you had to do COW by hand before doing any
user access. But we haven't supported that in a long time, and these
days the 'type' argument is a purely historical artifact.
A discussion about extending 'user_access_begin()' to do the range
checking resulted this patch, because there is no way we're going to
move the old VERIFY_xyz interface to that model. And it's best done at
the end of the merge window when I've done most of my merges, so let's
just get this done once and for all.
This patch was mostly done with a sed-script, with manual fix-ups for
the cases that weren't of the trivial 'access_ok(VERIFY_xyz' form.
There were a couple of notable cases:
- csky still had the old "verify_area()" name as an alias.
- the iter_iov code had magical hardcoded knowledge of the actual
values of VERIFY_{READ,WRITE} (not that they mattered, since nothing
really used it)
- microblaze used the type argument for a debug printout
but other than those oddities this should be a total no-op patch.
I tried to fix up all architectures, did fairly extensive grepping for
access_ok() uses, and the changes are trivial, but I may have missed
something. Any missed conversion should be trivially fixable, though.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
271 lines
7.2 KiB
C
271 lines
7.2 KiB
C
/*
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* Signal support for Hexagon processor
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*
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* Copyright (c) 2010-2012, The Linux Foundation. All rights reserved.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 and
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* only version 2 as published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
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* 02110-1301, USA.
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*/
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#include <linux/linkage.h>
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#include <linux/syscalls.h>
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#include <linux/tracehook.h>
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#include <linux/sched/task_stack.h>
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#include <asm/registers.h>
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#include <asm/thread_info.h>
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#include <asm/unistd.h>
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#include <linux/uaccess.h>
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#include <asm/ucontext.h>
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#include <asm/cacheflush.h>
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#include <asm/signal.h>
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#include <asm/vdso.h>
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struct rt_sigframe {
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unsigned long tramp[2];
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struct siginfo info;
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struct ucontext uc;
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};
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static void __user *get_sigframe(struct ksignal *ksig, struct pt_regs *regs,
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size_t frame_size)
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{
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unsigned long sp = sigsp(regs->r29, ksig);
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return (void __user *)((sp - frame_size) & ~(sizeof(long long) - 1));
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}
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static int setup_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc)
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{
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unsigned long tmp;
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int err = 0;
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err |= copy_to_user(&sc->sc_regs.r0, ®s->r00,
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32*sizeof(unsigned long));
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err |= __put_user(regs->sa0, &sc->sc_regs.sa0);
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err |= __put_user(regs->lc0, &sc->sc_regs.lc0);
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err |= __put_user(regs->sa1, &sc->sc_regs.sa1);
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err |= __put_user(regs->lc1, &sc->sc_regs.lc1);
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err |= __put_user(regs->m0, &sc->sc_regs.m0);
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err |= __put_user(regs->m1, &sc->sc_regs.m1);
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err |= __put_user(regs->usr, &sc->sc_regs.usr);
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err |= __put_user(regs->preds, &sc->sc_regs.p3_0);
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err |= __put_user(regs->gp, &sc->sc_regs.gp);
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err |= __put_user(regs->ugp, &sc->sc_regs.ugp);
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#if CONFIG_HEXAGON_ARCH_VERSION >= 4
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err |= __put_user(regs->cs0, &sc->sc_regs.cs0);
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err |= __put_user(regs->cs1, &sc->sc_regs.cs1);
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#endif
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tmp = pt_elr(regs); err |= __put_user(tmp, &sc->sc_regs.pc);
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tmp = pt_cause(regs); err |= __put_user(tmp, &sc->sc_regs.cause);
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tmp = pt_badva(regs); err |= __put_user(tmp, &sc->sc_regs.badva);
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return err;
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}
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static int restore_sigcontext(struct pt_regs *regs,
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struct sigcontext __user *sc)
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{
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unsigned long tmp;
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int err = 0;
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err |= copy_from_user(®s->r00, &sc->sc_regs.r0,
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32 * sizeof(unsigned long));
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err |= __get_user(regs->sa0, &sc->sc_regs.sa0);
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err |= __get_user(regs->lc0, &sc->sc_regs.lc0);
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err |= __get_user(regs->sa1, &sc->sc_regs.sa1);
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err |= __get_user(regs->lc1, &sc->sc_regs.lc1);
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err |= __get_user(regs->m0, &sc->sc_regs.m0);
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err |= __get_user(regs->m1, &sc->sc_regs.m1);
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err |= __get_user(regs->usr, &sc->sc_regs.usr);
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err |= __get_user(regs->preds, &sc->sc_regs.p3_0);
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err |= __get_user(regs->gp, &sc->sc_regs.gp);
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err |= __get_user(regs->ugp, &sc->sc_regs.ugp);
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#if CONFIG_HEXAGON_ARCH_VERSION >= 4
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err |= __get_user(regs->cs0, &sc->sc_regs.cs0);
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err |= __get_user(regs->cs1, &sc->sc_regs.cs1);
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#endif
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err |= __get_user(tmp, &sc->sc_regs.pc); pt_set_elr(regs, tmp);
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return err;
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}
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/*
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* Setup signal stack frame with siginfo structure
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*/
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static int setup_rt_frame(struct ksignal *ksig, sigset_t *set,
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struct pt_regs *regs)
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{
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int err = 0;
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struct rt_sigframe __user *frame;
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struct hexagon_vdso *vdso = current->mm->context.vdso;
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frame = get_sigframe(ksig, regs, sizeof(struct rt_sigframe));
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if (!access_ok(frame, sizeof(struct rt_sigframe)))
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return -EFAULT;
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if (copy_siginfo_to_user(&frame->info, &ksig->info))
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return -EFAULT;
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/* The on-stack signal trampoline is no longer executed;
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* however, the libgcc signal frame unwinding code checks for
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* the presence of these two numeric magic values.
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*/
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err |= __put_user(0x7800d166, &frame->tramp[0]);
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err |= __put_user(0x5400c004, &frame->tramp[1]);
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err |= setup_sigcontext(regs, &frame->uc.uc_mcontext);
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err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
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err |= __save_altstack(&frame->uc.uc_stack, user_stack_pointer(regs));
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if (err)
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return -EFAULT;
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/* Load r0/r1 pair with signumber/siginfo pointer... */
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regs->r0100 = ((unsigned long long)((unsigned long)&frame->info) << 32)
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| (unsigned long long)ksig->sig;
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regs->r02 = (unsigned long) &frame->uc;
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regs->r31 = (unsigned long) vdso->rt_signal_trampoline;
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pt_psp(regs) = (unsigned long) frame;
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pt_set_elr(regs, (unsigned long)ksig->ka.sa.sa_handler);
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return 0;
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}
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/*
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* Setup invocation of signal handler
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*/
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static void handle_signal(struct ksignal *ksig, struct pt_regs *regs)
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{
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int ret;
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/*
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* If we're handling a signal that aborted a system call,
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* set up the error return value before adding the signal
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* frame to the stack.
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*/
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if (regs->syscall_nr >= 0) {
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switch (regs->r00) {
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case -ERESTART_RESTARTBLOCK:
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case -ERESTARTNOHAND:
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regs->r00 = -EINTR;
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break;
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case -ERESTARTSYS:
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if (!(ksig->ka.sa.sa_flags & SA_RESTART)) {
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regs->r00 = -EINTR;
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break;
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}
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/* Fall through */
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case -ERESTARTNOINTR:
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regs->r06 = regs->syscall_nr;
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pt_set_elr(regs, pt_elr(regs) - 4);
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regs->r00 = regs->restart_r0;
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break;
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default:
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break;
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}
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}
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/*
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* Set up the stack frame; not doing the SA_SIGINFO thing. We
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* only set up the rt_frame flavor.
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*/
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/* If there was an error on setup, no signal was delivered. */
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ret = setup_rt_frame(ksig, sigmask_to_save(), regs);
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signal_setup_done(ret, ksig, test_thread_flag(TIF_SINGLESTEP));
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}
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/*
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* Called from return-from-event code.
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*/
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void do_signal(struct pt_regs *regs)
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{
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struct ksignal ksig;
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if (!user_mode(regs))
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return;
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if (get_signal(&ksig)) {
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handle_signal(&ksig, regs);
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return;
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}
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/*
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* No (more) signals; if we came from a system call, handle the restart.
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*/
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if (regs->syscall_nr >= 0) {
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switch (regs->r00) {
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case -ERESTARTNOHAND:
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case -ERESTARTSYS:
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case -ERESTARTNOINTR:
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regs->r06 = regs->syscall_nr;
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break;
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case -ERESTART_RESTARTBLOCK:
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regs->r06 = __NR_restart_syscall;
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break;
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default:
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goto no_restart;
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}
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pt_set_elr(regs, pt_elr(regs) - 4);
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regs->r00 = regs->restart_r0;
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}
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no_restart:
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/* If there's no signal to deliver, put the saved sigmask back */
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restore_saved_sigmask();
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}
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/*
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* Architecture-specific wrappers for signal-related system calls
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*/
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asmlinkage int sys_rt_sigreturn(void)
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{
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struct pt_regs *regs = current_pt_regs();
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struct rt_sigframe __user *frame;
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sigset_t blocked;
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/* Always make any pending restarted system calls return -EINTR */
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current->restart_block.fn = do_no_restart_syscall;
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frame = (struct rt_sigframe __user *)pt_psp(regs);
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if (!access_ok(frame, sizeof(*frame)))
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goto badframe;
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if (__copy_from_user(&blocked, &frame->uc.uc_sigmask, sizeof(blocked)))
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goto badframe;
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set_current_blocked(&blocked);
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if (restore_sigcontext(regs, &frame->uc.uc_mcontext))
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goto badframe;
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/* Restore the user's stack as well */
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pt_psp(regs) = regs->r29;
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regs->syscall_nr = -1;
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if (restore_altstack(&frame->uc.uc_stack))
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goto badframe;
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return regs->r00;
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badframe:
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force_sig(SIGSEGV, current);
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return 0;
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}
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