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96a68b14db
Our sigreturn functions make use of a macro named nabi_no_regargs to declare 8 dummy arguments to a function, forcing the compiler to expect a pt_regs structure on the stack rather than in argument registers. This is an ugly hack which unnecessarily causes these sigreturn functions to need to care about the calling convention of the ABI the kernel is built for. Although this is abstracted via nabi_no_regargs, it's still ugly & unnecessary. Remove nabi_no_regargs & the struct pt_regs argument from sigreturn functions, and instead use current_pt_regs() to find the struct pt_regs on the stack, which works cleanly regardless of ABI. Signed-off-by: Paul Burton <paul.burton@mips.com> Patchwork: https://patchwork.linux-mips.org/patch/20106/ Cc: James Hogan <jhogan@kernel.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: linux-mips@linux-mips.org
291 lines
7.4 KiB
C
291 lines
7.4 KiB
C
/*
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* This file is subject to the terms and conditions of the GNU General Public
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* License. See the file "COPYING" in the main directory of this archive
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* for more details.
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*
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* Copyright (C) 1991, 1992 Linus Torvalds
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* Copyright (C) 1994 - 2000, 2006 Ralf Baechle
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* Copyright (C) 1999, 2000 Silicon Graphics, Inc.
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* Copyright (C) 2016, Imagination Technologies Ltd.
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*/
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#include <linux/compiler.h>
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#include <linux/errno.h>
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#include <linux/signal.h>
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#include <linux/sched/signal.h>
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#include <linux/uaccess.h>
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#include <asm/abi.h>
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#include <asm/compat-signal.h>
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#include <asm/dsp.h>
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#include <asm/sim.h>
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#include <asm/unistd.h>
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#include "signal-common.h"
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/*
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* Including <asm/unistd.h> would give use the 64-bit syscall numbers ...
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*/
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#define __NR_O32_restart_syscall 4253
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struct sigframe32 {
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u32 sf_ass[4]; /* argument save space for o32 */
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u32 sf_pad[2]; /* Was: signal trampoline */
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struct sigcontext32 sf_sc;
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compat_sigset_t sf_mask;
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};
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struct ucontext32 {
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u32 uc_flags;
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s32 uc_link;
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compat_stack_t uc_stack;
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struct sigcontext32 uc_mcontext;
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compat_sigset_t uc_sigmask; /* mask last for extensibility */
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};
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struct rt_sigframe32 {
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u32 rs_ass[4]; /* argument save space for o32 */
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u32 rs_pad[2]; /* Was: signal trampoline */
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compat_siginfo_t rs_info;
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struct ucontext32 rs_uc;
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};
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static int setup_sigcontext32(struct pt_regs *regs,
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struct sigcontext32 __user *sc)
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{
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int err = 0;
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int i;
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err |= __put_user(regs->cp0_epc, &sc->sc_pc);
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err |= __put_user(0, &sc->sc_regs[0]);
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for (i = 1; i < 32; i++)
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err |= __put_user(regs->regs[i], &sc->sc_regs[i]);
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err |= __put_user(regs->hi, &sc->sc_mdhi);
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err |= __put_user(regs->lo, &sc->sc_mdlo);
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if (cpu_has_dsp) {
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err |= __put_user(rddsp(DSP_MASK), &sc->sc_dsp);
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err |= __put_user(mfhi1(), &sc->sc_hi1);
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err |= __put_user(mflo1(), &sc->sc_lo1);
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err |= __put_user(mfhi2(), &sc->sc_hi2);
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err |= __put_user(mflo2(), &sc->sc_lo2);
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err |= __put_user(mfhi3(), &sc->sc_hi3);
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err |= __put_user(mflo3(), &sc->sc_lo3);
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}
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/*
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* Save FPU state to signal context. Signal handler
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* will "inherit" current FPU state.
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*/
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err |= protected_save_fp_context(sc);
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return err;
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}
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static int restore_sigcontext32(struct pt_regs *regs,
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struct sigcontext32 __user *sc)
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{
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int err = 0;
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s32 treg;
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int i;
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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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err |= __get_user(regs->cp0_epc, &sc->sc_pc);
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err |= __get_user(regs->hi, &sc->sc_mdhi);
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err |= __get_user(regs->lo, &sc->sc_mdlo);
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if (cpu_has_dsp) {
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err |= __get_user(treg, &sc->sc_hi1); mthi1(treg);
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err |= __get_user(treg, &sc->sc_lo1); mtlo1(treg);
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err |= __get_user(treg, &sc->sc_hi2); mthi2(treg);
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err |= __get_user(treg, &sc->sc_lo2); mtlo2(treg);
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err |= __get_user(treg, &sc->sc_hi3); mthi3(treg);
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err |= __get_user(treg, &sc->sc_lo3); mtlo3(treg);
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err |= __get_user(treg, &sc->sc_dsp); wrdsp(treg, DSP_MASK);
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}
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for (i = 1; i < 32; i++)
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err |= __get_user(regs->regs[i], &sc->sc_regs[i]);
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return err ?: protected_restore_fp_context(sc);
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}
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static int setup_frame_32(void *sig_return, struct ksignal *ksig,
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struct pt_regs *regs, sigset_t *set)
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{
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struct sigframe32 __user *frame;
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int err = 0;
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frame = get_sigframe(ksig, regs, sizeof(*frame));
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if (!access_ok(VERIFY_WRITE, frame, sizeof (*frame)))
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return -EFAULT;
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err |= setup_sigcontext32(regs, &frame->sf_sc);
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err |= __copy_conv_sigset_to_user(&frame->sf_mask, set);
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if (err)
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return -EFAULT;
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/*
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* Arguments to signal handler:
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*
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* a0 = signal number
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* a1 = 0 (should be cause)
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* a2 = pointer to struct sigcontext
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*
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* $25 and c0_epc point to the signal handler, $29 points to the
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* struct sigframe.
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*/
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regs->regs[ 4] = ksig->sig;
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regs->regs[ 5] = 0;
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regs->regs[ 6] = (unsigned long) &frame->sf_sc;
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regs->regs[29] = (unsigned long) frame;
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regs->regs[31] = (unsigned long) sig_return;
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regs->cp0_epc = regs->regs[25] = (unsigned long) ksig->ka.sa.sa_handler;
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DEBUGP("SIG deliver (%s:%d): sp=0x%p pc=0x%lx ra=0x%lx\n",
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current->comm, current->pid,
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frame, regs->cp0_epc, regs->regs[31]);
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return 0;
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}
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asmlinkage void sys32_rt_sigreturn(void)
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{
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struct rt_sigframe32 __user *frame;
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struct pt_regs *regs;
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sigset_t set;
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int sig;
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regs = current_pt_regs();
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frame = (struct rt_sigframe32 __user *)regs->regs[29];
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if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
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goto badframe;
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if (__copy_conv_sigset_from_user(&set, &frame->rs_uc.uc_sigmask))
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goto badframe;
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set_current_blocked(&set);
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sig = restore_sigcontext32(regs, &frame->rs_uc.uc_mcontext);
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if (sig < 0)
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goto badframe;
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else if (sig)
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force_sig(sig, current);
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if (compat_restore_altstack(&frame->rs_uc.uc_stack))
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goto badframe;
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/*
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* Don't let your children do this ...
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*/
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__asm__ __volatile__(
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"move\t$29, %0\n\t"
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"j\tsyscall_exit"
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: /* no outputs */
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: "r" (regs));
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/* Unreached */
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badframe:
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force_sig(SIGSEGV, current);
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}
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static int setup_rt_frame_32(void *sig_return, struct ksignal *ksig,
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struct pt_regs *regs, sigset_t *set)
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{
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struct rt_sigframe32 __user *frame;
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int err = 0;
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frame = get_sigframe(ksig, regs, sizeof(*frame));
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if (!access_ok(VERIFY_WRITE, frame, sizeof (*frame)))
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return -EFAULT;
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/* Convert (siginfo_t -> compat_siginfo_t) and copy to user. */
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err |= copy_siginfo_to_user32(&frame->rs_info, &ksig->info);
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/* Create the ucontext. */
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err |= __put_user(0, &frame->rs_uc.uc_flags);
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err |= __put_user(0, &frame->rs_uc.uc_link);
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err |= __compat_save_altstack(&frame->rs_uc.uc_stack, regs->regs[29]);
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err |= setup_sigcontext32(regs, &frame->rs_uc.uc_mcontext);
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err |= __copy_conv_sigset_to_user(&frame->rs_uc.uc_sigmask, set);
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if (err)
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return -EFAULT;
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/*
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* Arguments to signal handler:
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*
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* a0 = signal number
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* a1 = 0 (should be cause)
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* a2 = pointer to ucontext
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*
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* $25 and c0_epc point to the signal handler, $29 points to
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* the struct rt_sigframe32.
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*/
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regs->regs[ 4] = ksig->sig;
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regs->regs[ 5] = (unsigned long) &frame->rs_info;
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regs->regs[ 6] = (unsigned long) &frame->rs_uc;
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regs->regs[29] = (unsigned long) frame;
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regs->regs[31] = (unsigned long) sig_return;
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regs->cp0_epc = regs->regs[25] = (unsigned long) ksig->ka.sa.sa_handler;
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DEBUGP("SIG deliver (%s:%d): sp=0x%p pc=0x%lx ra=0x%lx\n",
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current->comm, current->pid,
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frame, regs->cp0_epc, regs->regs[31]);
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return 0;
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}
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/*
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* o32 compatibility on 64-bit kernels, without DSP ASE
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*/
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struct mips_abi mips_abi_32 = {
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.setup_frame = setup_frame_32,
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.setup_rt_frame = setup_rt_frame_32,
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.restart = __NR_O32_restart_syscall,
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.off_sc_fpregs = offsetof(struct sigcontext32, sc_fpregs),
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.off_sc_fpc_csr = offsetof(struct sigcontext32, sc_fpc_csr),
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.off_sc_used_math = offsetof(struct sigcontext32, sc_used_math),
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.vdso = &vdso_image_o32,
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};
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asmlinkage void sys32_sigreturn(void)
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{
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struct sigframe32 __user *frame;
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struct pt_regs *regs;
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sigset_t blocked;
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int sig;
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regs = current_pt_regs();
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frame = (struct sigframe32 __user *)regs->regs[29];
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if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
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goto badframe;
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if (__copy_conv_sigset_from_user(&blocked, &frame->sf_mask))
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goto badframe;
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set_current_blocked(&blocked);
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sig = restore_sigcontext32(regs, &frame->sf_sc);
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if (sig < 0)
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goto badframe;
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else if (sig)
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force_sig(sig, current);
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/*
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* Don't let your children do this ...
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*/
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__asm__ __volatile__(
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"move\t$29, %0\n\t"
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"j\tsyscall_exit"
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: /* no outputs */
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: "r" (regs));
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/* Unreached */
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badframe:
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force_sig(SIGSEGV, current);
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}
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