562 lines
17 KiB
C
562 lines
17 KiB
C
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// SPDX-License-Identifier: GPL-2.0
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/*
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* arch/sparc64/kernel/signal.c
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*
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* Copyright (C) 1991, 1992 Linus Torvalds
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* Copyright (C) 1995, 2008 David S. Miller (davem@davemloft.net)
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* Copyright (C) 1996 Miguel de Icaza (miguel@nuclecu.unam.mx)
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* Copyright (C) 1997 Eddie C. Dost (ecd@skynet.be)
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* Copyright (C) 1997,1998 Jakub Jelinek (jj@sunsite.mff.cuni.cz)
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*/
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#include <linux/sched.h>
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#include <linux/kernel.h>
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#include <linux/signal.h>
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#include <linux/errno.h>
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#include <linux/wait.h>
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#include <linux/ptrace.h>
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#include <linux/tracehook.h>
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#include <linux/unistd.h>
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#include <linux/mm.h>
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#include <linux/tty.h>
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#include <linux/binfmts.h>
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#include <linux/bitops.h>
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#include <linux/context_tracking.h>
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#include <linux/uaccess.h>
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#include <asm/ptrace.h>
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#include <asm/pgtable.h>
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#include <asm/fpumacro.h>
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#include <asm/uctx.h>
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#include <asm/siginfo.h>
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#include <asm/visasm.h>
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#include <asm/switch_to.h>
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#include <asm/cacheflush.h>
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#include "sigutil.h"
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#include "systbls.h"
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#include "kernel.h"
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#include "entry.h"
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/* {set, get}context() needed for 64-bit SparcLinux userland. */
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asmlinkage void sparc64_set_context(struct pt_regs *regs)
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{
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struct ucontext __user *ucp = (struct ucontext __user *)
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regs->u_regs[UREG_I0];
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enum ctx_state prev_state = exception_enter();
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mc_gregset_t __user *grp;
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unsigned long pc, npc, tstate;
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unsigned long fp, i7;
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unsigned char fenab;
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int err;
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synchronize_user_stack();
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if (get_thread_wsaved() ||
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(((unsigned long)ucp) & (sizeof(unsigned long)-1)) ||
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(!__access_ok(ucp, sizeof(*ucp))))
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goto do_sigsegv;
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grp = &ucp->uc_mcontext.mc_gregs;
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err = __get_user(pc, &((*grp)[MC_PC]));
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err |= __get_user(npc, &((*grp)[MC_NPC]));
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if (err || ((pc | npc) & 3))
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goto do_sigsegv;
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if (regs->u_regs[UREG_I1]) {
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sigset_t set;
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if (_NSIG_WORDS == 1) {
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if (__get_user(set.sig[0], &ucp->uc_sigmask.sig[0]))
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goto do_sigsegv;
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} else {
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if (__copy_from_user(&set, &ucp->uc_sigmask, sizeof(sigset_t)))
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goto do_sigsegv;
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}
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set_current_blocked(&set);
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}
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if (test_thread_flag(TIF_32BIT)) {
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pc &= 0xffffffff;
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npc &= 0xffffffff;
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}
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regs->tpc = pc;
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regs->tnpc = npc;
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err |= __get_user(regs->y, &((*grp)[MC_Y]));
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err |= __get_user(tstate, &((*grp)[MC_TSTATE]));
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regs->tstate &= ~(TSTATE_ASI | TSTATE_ICC | TSTATE_XCC);
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regs->tstate |= (tstate & (TSTATE_ASI | TSTATE_ICC | TSTATE_XCC));
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err |= __get_user(regs->u_regs[UREG_G1], (&(*grp)[MC_G1]));
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err |= __get_user(regs->u_regs[UREG_G2], (&(*grp)[MC_G2]));
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err |= __get_user(regs->u_regs[UREG_G3], (&(*grp)[MC_G3]));
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err |= __get_user(regs->u_regs[UREG_G4], (&(*grp)[MC_G4]));
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err |= __get_user(regs->u_regs[UREG_G5], (&(*grp)[MC_G5]));
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err |= __get_user(regs->u_regs[UREG_G6], (&(*grp)[MC_G6]));
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/* Skip %g7 as that's the thread register in userspace. */
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err |= __get_user(regs->u_regs[UREG_I0], (&(*grp)[MC_O0]));
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err |= __get_user(regs->u_regs[UREG_I1], (&(*grp)[MC_O1]));
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err |= __get_user(regs->u_regs[UREG_I2], (&(*grp)[MC_O2]));
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err |= __get_user(regs->u_regs[UREG_I3], (&(*grp)[MC_O3]));
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err |= __get_user(regs->u_regs[UREG_I4], (&(*grp)[MC_O4]));
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err |= __get_user(regs->u_regs[UREG_I5], (&(*grp)[MC_O5]));
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err |= __get_user(regs->u_regs[UREG_I6], (&(*grp)[MC_O6]));
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err |= __get_user(regs->u_regs[UREG_I7], (&(*grp)[MC_O7]));
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err |= __get_user(fp, &(ucp->uc_mcontext.mc_fp));
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err |= __get_user(i7, &(ucp->uc_mcontext.mc_i7));
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err |= __put_user(fp,
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(&(((struct reg_window __user *)(STACK_BIAS+regs->u_regs[UREG_I6]))->ins[6])));
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err |= __put_user(i7,
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(&(((struct reg_window __user *)(STACK_BIAS+regs->u_regs[UREG_I6]))->ins[7])));
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err |= __get_user(fenab, &(ucp->uc_mcontext.mc_fpregs.mcfpu_enab));
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if (fenab) {
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unsigned long *fpregs = current_thread_info()->fpregs;
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unsigned long fprs;
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fprs_write(0);
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err |= __get_user(fprs, &(ucp->uc_mcontext.mc_fpregs.mcfpu_fprs));
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if (fprs & FPRS_DL)
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err |= copy_from_user(fpregs,
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&(ucp->uc_mcontext.mc_fpregs.mcfpu_fregs),
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(sizeof(unsigned int) * 32));
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if (fprs & FPRS_DU)
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err |= copy_from_user(fpregs+16,
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((unsigned long __user *)&(ucp->uc_mcontext.mc_fpregs.mcfpu_fregs))+16,
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(sizeof(unsigned int) * 32));
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err |= __get_user(current_thread_info()->xfsr[0],
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&(ucp->uc_mcontext.mc_fpregs.mcfpu_fsr));
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err |= __get_user(current_thread_info()->gsr[0],
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&(ucp->uc_mcontext.mc_fpregs.mcfpu_gsr));
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regs->tstate &= ~TSTATE_PEF;
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}
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if (err)
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goto do_sigsegv;
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out:
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exception_exit(prev_state);
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return;
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do_sigsegv:
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force_sig(SIGSEGV);
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goto out;
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}
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asmlinkage void sparc64_get_context(struct pt_regs *regs)
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{
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struct ucontext __user *ucp = (struct ucontext __user *)
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regs->u_regs[UREG_I0];
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enum ctx_state prev_state = exception_enter();
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mc_gregset_t __user *grp;
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mcontext_t __user *mcp;
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unsigned long fp, i7;
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unsigned char fenab;
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int err;
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synchronize_user_stack();
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if (get_thread_wsaved() || clear_user(ucp, sizeof(*ucp)))
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goto do_sigsegv;
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#if 1
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fenab = 0; /* IMO get_context is like any other system call, thus modifies FPU state -jj */
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#else
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fenab = (current_thread_info()->fpsaved[0] & FPRS_FEF);
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#endif
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mcp = &ucp->uc_mcontext;
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grp = &mcp->mc_gregs;
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/* Skip over the trap instruction, first. */
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if (test_thread_flag(TIF_32BIT)) {
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regs->tpc = (regs->tnpc & 0xffffffff);
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regs->tnpc = (regs->tnpc + 4) & 0xffffffff;
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} else {
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regs->tpc = regs->tnpc;
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regs->tnpc += 4;
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}
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err = 0;
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if (_NSIG_WORDS == 1)
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err |= __put_user(current->blocked.sig[0],
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(unsigned long __user *)&ucp->uc_sigmask);
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else
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err |= __copy_to_user(&ucp->uc_sigmask, ¤t->blocked,
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sizeof(sigset_t));
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err |= __put_user(regs->tstate, &((*grp)[MC_TSTATE]));
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err |= __put_user(regs->tpc, &((*grp)[MC_PC]));
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err |= __put_user(regs->tnpc, &((*grp)[MC_NPC]));
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err |= __put_user(regs->y, &((*grp)[MC_Y]));
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err |= __put_user(regs->u_regs[UREG_G1], &((*grp)[MC_G1]));
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err |= __put_user(regs->u_regs[UREG_G2], &((*grp)[MC_G2]));
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err |= __put_user(regs->u_regs[UREG_G3], &((*grp)[MC_G3]));
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err |= __put_user(regs->u_regs[UREG_G4], &((*grp)[MC_G4]));
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err |= __put_user(regs->u_regs[UREG_G5], &((*grp)[MC_G5]));
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err |= __put_user(regs->u_regs[UREG_G6], &((*grp)[MC_G6]));
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err |= __put_user(regs->u_regs[UREG_G7], &((*grp)[MC_G7]));
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err |= __put_user(regs->u_regs[UREG_I0], &((*grp)[MC_O0]));
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err |= __put_user(regs->u_regs[UREG_I1], &((*grp)[MC_O1]));
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err |= __put_user(regs->u_regs[UREG_I2], &((*grp)[MC_O2]));
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err |= __put_user(regs->u_regs[UREG_I3], &((*grp)[MC_O3]));
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err |= __put_user(regs->u_regs[UREG_I4], &((*grp)[MC_O4]));
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err |= __put_user(regs->u_regs[UREG_I5], &((*grp)[MC_O5]));
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err |= __put_user(regs->u_regs[UREG_I6], &((*grp)[MC_O6]));
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err |= __put_user(regs->u_regs[UREG_I7], &((*grp)[MC_O7]));
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err |= __get_user(fp,
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(&(((struct reg_window __user *)(STACK_BIAS+regs->u_regs[UREG_I6]))->ins[6])));
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err |= __get_user(i7,
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(&(((struct reg_window __user *)(STACK_BIAS+regs->u_regs[UREG_I6]))->ins[7])));
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err |= __put_user(fp, &(mcp->mc_fp));
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err |= __put_user(i7, &(mcp->mc_i7));
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err |= __put_user(fenab, &(mcp->mc_fpregs.mcfpu_enab));
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if (fenab) {
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unsigned long *fpregs = current_thread_info()->fpregs;
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unsigned long fprs;
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fprs = current_thread_info()->fpsaved[0];
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if (fprs & FPRS_DL)
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err |= copy_to_user(&(mcp->mc_fpregs.mcfpu_fregs), fpregs,
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(sizeof(unsigned int) * 32));
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if (fprs & FPRS_DU)
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err |= copy_to_user(
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((unsigned long __user *)&(mcp->mc_fpregs.mcfpu_fregs))+16, fpregs+16,
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(sizeof(unsigned int) * 32));
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err |= __put_user(current_thread_info()->xfsr[0], &(mcp->mc_fpregs.mcfpu_fsr));
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err |= __put_user(current_thread_info()->gsr[0], &(mcp->mc_fpregs.mcfpu_gsr));
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err |= __put_user(fprs, &(mcp->mc_fpregs.mcfpu_fprs));
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}
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if (err)
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goto do_sigsegv;
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out:
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exception_exit(prev_state);
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return;
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do_sigsegv:
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force_sig(SIGSEGV);
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goto out;
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}
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/* Checks if the fp is valid. We always build rt signal frames which
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* are 16-byte aligned, therefore we can always enforce that the
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* restore frame has that property as well.
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*/
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static bool invalid_frame_pointer(void __user *fp)
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{
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if (((unsigned long) fp) & 15)
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return true;
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return false;
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}
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struct rt_signal_frame {
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struct sparc_stackf ss;
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siginfo_t info;
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struct pt_regs regs;
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__siginfo_fpu_t __user *fpu_save;
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stack_t stack;
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sigset_t mask;
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__siginfo_rwin_t *rwin_save;
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};
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void do_rt_sigreturn(struct pt_regs *regs)
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{
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unsigned long tpc, tnpc, tstate, ufp;
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struct rt_signal_frame __user *sf;
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__siginfo_fpu_t __user *fpu_save;
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__siginfo_rwin_t __user *rwin_save;
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sigset_t set;
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int err;
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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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synchronize_user_stack ();
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sf = (struct rt_signal_frame __user *)
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(regs->u_regs [UREG_FP] + STACK_BIAS);
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/* 1. Make sure we are not getting garbage from the user */
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if (invalid_frame_pointer(sf))
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goto segv;
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if (get_user(ufp, &sf->regs.u_regs[UREG_FP]))
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goto segv;
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if ((ufp + STACK_BIAS) & 0x7)
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goto segv;
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err = __get_user(tpc, &sf->regs.tpc);
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err |= __get_user(tnpc, &sf->regs.tnpc);
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if (test_thread_flag(TIF_32BIT)) {
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tpc &= 0xffffffff;
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tnpc &= 0xffffffff;
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}
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err |= ((tpc | tnpc) & 3);
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/* 2. Restore the state */
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err |= __get_user(regs->y, &sf->regs.y);
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err |= __get_user(tstate, &sf->regs.tstate);
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err |= copy_from_user(regs->u_regs, sf->regs.u_regs, sizeof(regs->u_regs));
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/* User can only change condition codes and %asi in %tstate. */
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regs->tstate &= ~(TSTATE_ASI | TSTATE_ICC | TSTATE_XCC);
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regs->tstate |= (tstate & (TSTATE_ASI | TSTATE_ICC | TSTATE_XCC));
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err |= __get_user(fpu_save, &sf->fpu_save);
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if (!err && fpu_save)
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err |= restore_fpu_state(regs, fpu_save);
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err |= __copy_from_user(&set, &sf->mask, sizeof(sigset_t));
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err |= restore_altstack(&sf->stack);
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if (err)
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goto segv;
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err |= __get_user(rwin_save, &sf->rwin_save);
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if (!err && rwin_save) {
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if (restore_rwin_state(rwin_save))
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goto segv;
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}
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regs->tpc = tpc;
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regs->tnpc = tnpc;
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/* Prevent syscall restart. */
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pt_regs_clear_syscall(regs);
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set_current_blocked(&set);
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return;
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segv:
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force_sig(SIGSEGV);
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}
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static inline void __user *get_sigframe(struct ksignal *ksig, struct pt_regs *regs, unsigned long framesize)
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{
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unsigned long sp = regs->u_regs[UREG_FP] + STACK_BIAS;
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/*
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* If we are on the alternate signal stack and would overflow it, don't.
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* Return an always-bogus address instead so we will die with SIGSEGV.
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*/
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if (on_sig_stack(sp) && !likely(on_sig_stack(sp - framesize)))
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return (void __user *) -1L;
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/* This is the X/Open sanctioned signal stack switching. */
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sp = sigsp(sp, ksig) - framesize;
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/* Always align the stack frame. This handles two cases. First,
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* sigaltstack need not be mindful of platform specific stack
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* alignment. Second, if we took this signal because the stack
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* is not aligned properly, we'd like to take the signal cleanly
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* and report that.
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*/
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sp &= ~15UL;
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return (void __user *) sp;
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}
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static inline int
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setup_rt_frame(struct ksignal *ksig, struct pt_regs *regs)
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{
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struct rt_signal_frame __user *sf;
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int wsaved, err, sf_size;
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void __user *tail;
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/* 1. Make sure everything is clean */
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synchronize_user_stack();
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save_and_clear_fpu();
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wsaved = get_thread_wsaved();
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||
|
sf_size = sizeof(struct rt_signal_frame);
|
||
|
if (current_thread_info()->fpsaved[0] & FPRS_FEF)
|
||
|
sf_size += sizeof(__siginfo_fpu_t);
|
||
|
if (wsaved)
|
||
|
sf_size += sizeof(__siginfo_rwin_t);
|
||
|
sf = (struct rt_signal_frame __user *)
|
||
|
get_sigframe(ksig, regs, sf_size);
|
||
|
|
||
|
if (invalid_frame_pointer (sf)) {
|
||
|
if (show_unhandled_signals)
|
||
|
pr_info("%s[%d] bad frame in setup_rt_frame: %016lx TPC %016lx O7 %016lx\n",
|
||
|
current->comm, current->pid, (unsigned long)sf,
|
||
|
regs->tpc, regs->u_regs[UREG_I7]);
|
||
|
force_sigsegv(ksig->sig);
|
||
|
return -EINVAL;
|
||
|
}
|
||
|
|
||
|
tail = (sf + 1);
|
||
|
|
||
|
/* 2. Save the current process state */
|
||
|
err = copy_to_user(&sf->regs, regs, sizeof (*regs));
|
||
|
|
||
|
if (current_thread_info()->fpsaved[0] & FPRS_FEF) {
|
||
|
__siginfo_fpu_t __user *fpu_save = tail;
|
||
|
tail += sizeof(__siginfo_fpu_t);
|
||
|
err |= save_fpu_state(regs, fpu_save);
|
||
|
err |= __put_user((u64)fpu_save, &sf->fpu_save);
|
||
|
} else {
|
||
|
err |= __put_user(0, &sf->fpu_save);
|
||
|
}
|
||
|
if (wsaved) {
|
||
|
__siginfo_rwin_t __user *rwin_save = tail;
|
||
|
tail += sizeof(__siginfo_rwin_t);
|
||
|
err |= save_rwin_state(wsaved, rwin_save);
|
||
|
err |= __put_user((u64)rwin_save, &sf->rwin_save);
|
||
|
set_thread_wsaved(0);
|
||
|
} else {
|
||
|
err |= __put_user(0, &sf->rwin_save);
|
||
|
}
|
||
|
|
||
|
/* Setup sigaltstack */
|
||
|
err |= __save_altstack(&sf->stack, regs->u_regs[UREG_FP]);
|
||
|
|
||
|
err |= copy_to_user(&sf->mask, sigmask_to_save(), sizeof(sigset_t));
|
||
|
|
||
|
if (!wsaved) {
|
||
|
err |= copy_in_user((u64 __user *)sf,
|
||
|
(u64 __user *)(regs->u_regs[UREG_FP] +
|
||
|
STACK_BIAS),
|
||
|
sizeof(struct reg_window));
|
||
|
} else {
|
||
|
struct reg_window *rp;
|
||
|
|
||
|
rp = ¤t_thread_info()->reg_window[wsaved - 1];
|
||
|
err |= copy_to_user(sf, rp, sizeof(struct reg_window));
|
||
|
}
|
||
|
if (ksig->ka.sa.sa_flags & SA_SIGINFO)
|
||
|
err |= copy_siginfo_to_user(&sf->info, &ksig->info);
|
||
|
else {
|
||
|
err |= __put_user(ksig->sig, &sf->info.si_signo);
|
||
|
err |= __put_user(SI_NOINFO, &sf->info.si_code);
|
||
|
}
|
||
|
if (err)
|
||
|
return err;
|
||
|
|
||
|
/* 3. signal handler back-trampoline and parameters */
|
||
|
regs->u_regs[UREG_FP] = ((unsigned long) sf) - STACK_BIAS;
|
||
|
regs->u_regs[UREG_I0] = ksig->sig;
|
||
|
regs->u_regs[UREG_I1] = (unsigned long) &sf->info;
|
||
|
|
||
|
/* The sigcontext is passed in this way because of how it
|
||
|
* is defined in GLIBC's /usr/include/bits/sigcontext.h
|
||
|
* for sparc64. It includes the 128 bytes of siginfo_t.
|
||
|
*/
|
||
|
regs->u_regs[UREG_I2] = (unsigned long) &sf->info;
|
||
|
|
||
|
/* 5. signal handler */
|
||
|
regs->tpc = (unsigned long) ksig->ka.sa.sa_handler;
|
||
|
regs->tnpc = (regs->tpc + 4);
|
||
|
if (test_thread_flag(TIF_32BIT)) {
|
||
|
regs->tpc &= 0xffffffff;
|
||
|
regs->tnpc &= 0xffffffff;
|
||
|
}
|
||
|
/* 4. return to kernel instructions */
|
||
|
regs->u_regs[UREG_I7] = (unsigned long)ksig->ka.ka_restorer;
|
||
|
return 0;
|
||
|
}
|
||
|
|
||
|
static inline void syscall_restart(unsigned long orig_i0, struct pt_regs *regs,
|
||
|
struct sigaction *sa)
|
||
|
{
|
||
|
switch (regs->u_regs[UREG_I0]) {
|
||
|
case ERESTART_RESTARTBLOCK:
|
||
|
case ERESTARTNOHAND:
|
||
|
no_system_call_restart:
|
||
|
regs->u_regs[UREG_I0] = EINTR;
|
||
|
regs->tstate |= (TSTATE_ICARRY|TSTATE_XCARRY);
|
||
|
break;
|
||
|
case ERESTARTSYS:
|
||
|
if (!(sa->sa_flags & SA_RESTART))
|
||
|
goto no_system_call_restart;
|
||
|
/* fallthrough */
|
||
|
case ERESTARTNOINTR:
|
||
|
regs->u_regs[UREG_I0] = orig_i0;
|
||
|
regs->tpc -= 4;
|
||
|
regs->tnpc -= 4;
|
||
|
}
|
||
|
}
|
||
|
|
||
|
/* 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.
|
||
|
*/
|
||
|
static void do_signal(struct pt_regs *regs, unsigned long orig_i0)
|
||
|
{
|
||
|
struct ksignal ksig;
|
||
|
int restart_syscall;
|
||
|
bool has_handler;
|
||
|
|
||
|
/* It's a lot of work and synchronization to add a new ptrace
|
||
|
* register for GDB to save and restore in order to get
|
||
|
* orig_i0 correct for syscall restarts when debugging.
|
||
|
*
|
||
|
* Although it should be the case that most of the global
|
||
|
* registers are volatile across a system call, glibc already
|
||
|
* depends upon that fact that we preserve them. So we can't
|
||
|
* just use any global register to save away the orig_i0 value.
|
||
|
*
|
||
|
* In particular %g2, %g3, %g4, and %g5 are all assumed to be
|
||
|
* preserved across a system call trap by various pieces of
|
||
|
* code in glibc.
|
||
|
*
|
||
|
* %g7 is used as the "thread register". %g6 is not used in
|
||
|
* any fixed manner. %g6 is used as a scratch register and
|
||
|
* a compiler temporary, but it's value is never used across
|
||
|
* a system call. Therefore %g6 is usable for orig_i0 storage.
|
||
|
*/
|
||
|
if (pt_regs_is_syscall(regs) &&
|
||
|
(regs->tstate & (TSTATE_XCARRY | TSTATE_ICARRY)))
|
||
|
regs->u_regs[UREG_G6] = orig_i0;
|
||
|
|
||
|
#ifdef CONFIG_COMPAT
|
||
|
if (test_thread_flag(TIF_32BIT)) {
|
||
|
do_signal32(regs);
|
||
|
return;
|
||
|
}
|
||
|
#endif
|
||
|
|
||
|
has_handler = get_signal(&ksig);
|
||
|
|
||
|
restart_syscall = 0;
|
||
|
if (pt_regs_is_syscall(regs) &&
|
||
|
(regs->tstate & (TSTATE_XCARRY | TSTATE_ICARRY))) {
|
||
|
restart_syscall = 1;
|
||
|
orig_i0 = regs->u_regs[UREG_G6];
|
||
|
}
|
||
|
|
||
|
if (has_handler) {
|
||
|
if (restart_syscall)
|
||
|
syscall_restart(orig_i0, regs, &ksig.ka.sa);
|
||
|
signal_setup_done(setup_rt_frame(&ksig, regs), &ksig, 0);
|
||
|
} else {
|
||
|
if (restart_syscall) {
|
||
|
switch (regs->u_regs[UREG_I0]) {
|
||
|
case ERESTARTNOHAND:
|
||
|
case ERESTARTSYS:
|
||
|
case ERESTARTNOINTR:
|
||
|
/* replay the system call when we are done */
|
||
|
regs->u_regs[UREG_I0] = orig_i0;
|
||
|
regs->tpc -= 4;
|
||
|
regs->tnpc -= 4;
|
||
|
pt_regs_clear_syscall(regs);
|
||
|
/* fall through */
|
||
|
case ERESTART_RESTARTBLOCK:
|
||
|
regs->u_regs[UREG_G1] = __NR_restart_syscall;
|
||
|
regs->tpc -= 4;
|
||
|
regs->tnpc -= 4;
|
||
|
pt_regs_clear_syscall(regs);
|
||
|
}
|
||
|
}
|
||
|
restore_saved_sigmask();
|
||
|
}
|
||
|
}
|
||
|
|
||
|
void do_notify_resume(struct pt_regs *regs, unsigned long orig_i0, unsigned long thread_info_flags)
|
||
|
{
|
||
|
user_exit();
|
||
|
if (thread_info_flags & _TIF_UPROBE)
|
||
|
uprobe_notify_resume(regs);
|
||
|
if (thread_info_flags & _TIF_SIGPENDING)
|
||
|
do_signal(regs, orig_i0);
|
||
|
if (thread_info_flags & _TIF_NOTIFY_RESUME) {
|
||
|
clear_thread_flag(TIF_NOTIFY_RESUME);
|
||
|
tracehook_notify_resume(regs);
|
||
|
}
|
||
|
user_enter();
|
||
|
}
|
||
|
|