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8513c42edb
When delivering a signal, disable single stepping but call ptrace_notify if it was enabled before. The idea was taken from the x86 port. Signed-off-by: Bernd Schmidt <bernds_cb1@t-online.de> Signed-off-by: Bryan Wu <cooloney@kernel.org>
358 lines
9.4 KiB
C
358 lines
9.4 KiB
C
/*
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* File: arch/blackfin/kernel/signal.c
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* Based on:
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* Author:
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*
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* Created:
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* Description:
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*
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* Modified:
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* Copyright 2004-2006 Analog Devices Inc.
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*
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* Bugs: Enter bugs at http://blackfin.uclinux.org/
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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 as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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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, see the file COPYING, or write
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* to the Free Software Foundation, Inc.,
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* 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
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*/
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#include <linux/signal.h>
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#include <linux/syscalls.h>
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#include <linux/ptrace.h>
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#include <linux/tty.h>
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#include <linux/personality.h>
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#include <linux/binfmts.h>
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#include <linux/freezer.h>
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#include <linux/uaccess.h>
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#include <asm/cacheflush.h>
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#include <asm/ucontext.h>
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#include <asm/fixed_code.h>
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#define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
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/* Location of the trace bit in SYSCFG. */
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#define TRACE_BITS 0x0001
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struct fdpic_func_descriptor {
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unsigned long text;
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unsigned long GOT;
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};
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struct rt_sigframe {
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int sig;
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struct siginfo *pinfo;
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void *puc;
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/* This is no longer needed by the kernel, but unfortunately userspace
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* code expects it to be there. */
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char retcode[8];
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struct siginfo info;
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struct ucontext uc;
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};
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asmlinkage int sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss)
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{
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return do_sigaltstack(uss, uoss, rdusp());
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}
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static inline int
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rt_restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc, int *pr0)
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{
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unsigned long usp = 0;
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int err = 0;
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#define RESTORE(x) err |= __get_user(regs->x, &sc->sc_##x)
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/* restore passed registers */
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RESTORE(r0); RESTORE(r1); RESTORE(r2); RESTORE(r3);
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RESTORE(r4); RESTORE(r5); RESTORE(r6); RESTORE(r7);
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RESTORE(p0); RESTORE(p1); RESTORE(p2); RESTORE(p3);
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RESTORE(p4); RESTORE(p5);
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err |= __get_user(usp, &sc->sc_usp);
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wrusp(usp);
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RESTORE(a0w); RESTORE(a1w);
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RESTORE(a0x); RESTORE(a1x);
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RESTORE(astat);
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RESTORE(rets);
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RESTORE(pc);
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RESTORE(retx);
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RESTORE(fp);
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RESTORE(i0); RESTORE(i1); RESTORE(i2); RESTORE(i3);
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RESTORE(m0); RESTORE(m1); RESTORE(m2); RESTORE(m3);
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RESTORE(l0); RESTORE(l1); RESTORE(l2); RESTORE(l3);
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RESTORE(b0); RESTORE(b1); RESTORE(b2); RESTORE(b3);
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RESTORE(lc0); RESTORE(lc1);
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RESTORE(lt0); RESTORE(lt1);
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RESTORE(lb0); RESTORE(lb1);
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RESTORE(seqstat);
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regs->orig_p0 = -1; /* disable syscall checks */
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*pr0 = regs->r0;
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return err;
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}
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asmlinkage int do_rt_sigreturn(unsigned long __unused)
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{
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struct pt_regs *regs = (struct pt_regs *)__unused;
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unsigned long usp = rdusp();
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struct rt_sigframe *frame = (struct rt_sigframe *)(usp);
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sigset_t set;
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int r0;
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if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
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goto badframe;
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if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
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goto badframe;
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sigdelsetmask(&set, ~_BLOCKABLE);
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spin_lock_irq(¤t->sighand->siglock);
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current->blocked = set;
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recalc_sigpending();
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spin_unlock_irq(¤t->sighand->siglock);
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if (rt_restore_sigcontext(regs, &frame->uc.uc_mcontext, &r0))
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goto badframe;
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if (do_sigaltstack(&frame->uc.uc_stack, NULL, regs->usp) == -EFAULT)
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goto badframe;
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return r0;
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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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static inline int rt_setup_sigcontext(struct sigcontext *sc, struct pt_regs *regs)
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{
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int err = 0;
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#define SETUP(x) err |= __put_user(regs->x, &sc->sc_##x)
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SETUP(r0); SETUP(r1); SETUP(r2); SETUP(r3);
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SETUP(r4); SETUP(r5); SETUP(r6); SETUP(r7);
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SETUP(p0); SETUP(p1); SETUP(p2); SETUP(p3);
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SETUP(p4); SETUP(p5);
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err |= __put_user(rdusp(), &sc->sc_usp);
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SETUP(a0w); SETUP(a1w);
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SETUP(a0x); SETUP(a1x);
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SETUP(astat);
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SETUP(rets);
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SETUP(pc);
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SETUP(retx);
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SETUP(fp);
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SETUP(i0); SETUP(i1); SETUP(i2); SETUP(i3);
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SETUP(m0); SETUP(m1); SETUP(m2); SETUP(m3);
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SETUP(l0); SETUP(l1); SETUP(l2); SETUP(l3);
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SETUP(b0); SETUP(b1); SETUP(b2); SETUP(b3);
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SETUP(lc0); SETUP(lc1);
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SETUP(lt0); SETUP(lt1);
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SETUP(lb0); SETUP(lb1);
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SETUP(seqstat);
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return err;
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}
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static inline void *get_sigframe(struct k_sigaction *ka, struct pt_regs *regs,
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size_t frame_size)
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{
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unsigned long usp;
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/* Default to using normal stack. */
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usp = rdusp();
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/* This is the X/Open sanctioned signal stack switching. */
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if (ka->sa.sa_flags & SA_ONSTACK) {
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if (!on_sig_stack(usp))
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usp = current->sas_ss_sp + current->sas_ss_size;
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}
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return (void *)((usp - frame_size) & -8UL);
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}
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static int
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setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t * info,
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sigset_t * set, struct pt_regs *regs)
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{
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struct rt_sigframe *frame;
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int err = 0;
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frame = get_sigframe(ka, regs, sizeof(*frame));
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err |= __put_user((current_thread_info()->exec_domain
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&& current_thread_info()->exec_domain->signal_invmap
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&& sig < 32
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? current_thread_info()->exec_domain->
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signal_invmap[sig] : sig), &frame->sig);
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err |= __put_user(&frame->info, &frame->pinfo);
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err |= __put_user(&frame->uc, &frame->puc);
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err |= copy_siginfo_to_user(&frame->info, info);
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/* Create the ucontext. */
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err |= __put_user(0, &frame->uc.uc_flags);
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err |= __put_user(0, &frame->uc.uc_link);
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err |=
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__put_user((void *)current->sas_ss_sp, &frame->uc.uc_stack.ss_sp);
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err |= __put_user(sas_ss_flags(rdusp()), &frame->uc.uc_stack.ss_flags);
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err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
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err |= rt_setup_sigcontext(&frame->uc.uc_mcontext, regs);
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err |= copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
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if (err)
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goto give_sigsegv;
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/* Set up registers for signal handler */
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wrusp((unsigned long)frame);
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if (current->personality & FDPIC_FUNCPTRS) {
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struct fdpic_func_descriptor __user *funcptr =
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(struct fdpic_func_descriptor *) ka->sa.sa_handler;
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__get_user(regs->pc, &funcptr->text);
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__get_user(regs->p3, &funcptr->GOT);
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} else
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regs->pc = (unsigned long)ka->sa.sa_handler;
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regs->rets = SIGRETURN_STUB;
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regs->r0 = frame->sig;
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regs->r1 = (unsigned long)(&frame->info);
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regs->r2 = (unsigned long)(&frame->uc);
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/*
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* Clear the trace flag when entering the signal handler, but
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* notify any tracer that was single-stepping it. The tracer
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* may want to single-step inside the handler too.
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*/
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if (regs->syscfg & TRACE_BITS) {
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regs->syscfg &= ~TRACE_BITS;
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ptrace_notify(SIGTRAP);
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}
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return 0;
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give_sigsegv:
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if (sig == SIGSEGV)
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ka->sa.sa_handler = SIG_DFL;
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force_sig(SIGSEGV, current);
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return -EFAULT;
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}
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static inline void
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handle_restart(struct pt_regs *regs, struct k_sigaction *ka, int has_handler)
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{
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switch (regs->r0) {
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case -ERESTARTNOHAND:
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if (!has_handler)
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goto do_restart;
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regs->r0 = -EINTR;
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break;
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case -ERESTARTSYS:
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if (has_handler && !(ka->sa.sa_flags & SA_RESTART)) {
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regs->r0 = -EINTR;
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break;
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}
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/* fallthrough */
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case -ERESTARTNOINTR:
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do_restart:
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regs->p0 = regs->orig_p0;
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regs->r0 = regs->orig_r0;
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regs->pc -= 2;
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break;
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}
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}
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/*
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* OK, we're invoking a handler
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*/
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static int
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handle_signal(int sig, siginfo_t *info, struct k_sigaction *ka,
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sigset_t *oldset, struct pt_regs *regs)
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{
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int ret;
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/* are we from a system call? to see pt_regs->orig_p0 */
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if (regs->orig_p0 >= 0)
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/* If so, check system call restarting.. */
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handle_restart(regs, ka, 1);
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/* set up the stack frame */
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ret = setup_rt_frame(sig, ka, info, oldset, regs);
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if (ret == 0) {
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spin_lock_irq(¤t->sighand->siglock);
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sigorsets(¤t->blocked, ¤t->blocked,
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&ka->sa.sa_mask);
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if (!(ka->sa.sa_flags & SA_NODEFER))
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sigaddset(¤t->blocked, sig);
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recalc_sigpending();
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spin_unlock_irq(¤t->sighand->siglock);
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}
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return ret;
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}
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/*
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* Note that 'init' is a special process: it doesn't get signals it doesn't
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* want to handle. Thus you cannot kill init even with a SIGKILL even by
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* mistake.
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*
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* Note that we go through the signals twice: once to check the signals
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* that the kernel can handle, and then we build all the user-level signal
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* handling stack-frames in one go after that.
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*/
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asmlinkage void do_signal(struct pt_regs *regs)
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{
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siginfo_t info;
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int signr;
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struct k_sigaction ka;
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sigset_t *oldset;
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current->thread.esp0 = (unsigned long)regs;
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if (try_to_freeze())
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goto no_signal;
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if (test_thread_flag(TIF_RESTORE_SIGMASK))
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oldset = ¤t->saved_sigmask;
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else
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oldset = ¤t->blocked;
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signr = get_signal_to_deliver(&info, &ka, regs, NULL);
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if (signr > 0) {
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/* Whee! Actually deliver the signal. */
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if (handle_signal(signr, &info, &ka, oldset, regs) == 0) {
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/* a signal was successfully delivered; the saved
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* sigmask will have been stored in the signal frame,
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* and will be restored by sigreturn, so we can simply
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* clear the TIF_RESTORE_SIGMASK flag */
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if (test_thread_flag(TIF_RESTORE_SIGMASK))
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clear_thread_flag(TIF_RESTORE_SIGMASK);
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}
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return;
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}
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no_signal:
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/* Did we come from a system call? */
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if (regs->orig_p0 >= 0)
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/* Restart the system call - no handlers present */
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handle_restart(regs, NULL, 0);
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/* if there's no signal to deliver, we just put the saved sigmask
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* back */
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if (test_thread_flag(TIF_RESTORE_SIGMASK)) {
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clear_thread_flag(TIF_RESTORE_SIGMASK);
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sigprocmask(SIG_SETMASK, ¤t->saved_sigmask, NULL);
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}
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}
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