428 lines
13 KiB
C
428 lines
13 KiB
C
/*
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* linux/arch/unicore32/kernel/signal.c
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*
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* Code specific to PKUnity SoC and UniCore ISA
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*
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* Copyright (C) 2001-2010 GUAN Xue-tao
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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 as
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* published by the Free Software Foundation.
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*/
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#include <linux/errno.h>
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#include <linux/signal.h>
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#include <linux/personality.h>
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#include <linux/uaccess.h>
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#include <linux/tracehook.h>
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#include <linux/elf.h>
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#include <linux/unistd.h>
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#include <asm/cacheflush.h>
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#include <asm/ucontext.h>
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/*
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* For UniCore syscalls, we encode the syscall number into the instruction.
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*/
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#define SWI_SYS_SIGRETURN (0xff000000) /* error number for new abi */
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#define SWI_SYS_RT_SIGRETURN (0xff000000 | (__NR_rt_sigreturn))
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#define SWI_SYS_RESTART (0xff000000 | (__NR_restart_syscall))
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#define KERN_SIGRETURN_CODE (KUSER_VECPAGE_BASE + 0x00000500)
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#define KERN_RESTART_CODE (KERN_SIGRETURN_CODE + sizeof(sigreturn_codes))
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const unsigned long sigreturn_codes[3] = {
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SWI_SYS_SIGRETURN, SWI_SYS_RT_SIGRETURN,
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};
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const unsigned long syscall_restart_code[2] = {
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SWI_SYS_RESTART, /* swi __NR_restart_syscall */
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0x69efc004, /* ldr pc, [sp], #4 */
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};
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/*
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* Do a signal return; undo the signal stack. These are aligned to 64-bit.
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*/
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struct sigframe {
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struct ucontext uc;
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unsigned long retcode[2];
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};
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struct rt_sigframe {
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struct siginfo info;
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struct sigframe sig;
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};
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static int restore_sigframe(struct pt_regs *regs, struct sigframe __user *sf)
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{
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sigset_t set;
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int err;
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err = __copy_from_user(&set, &sf->uc.uc_sigmask, sizeof(set));
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if (err == 0)
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set_current_blocked(&set);
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err |= __get_user(regs->UCreg_00, &sf->uc.uc_mcontext.regs.UCreg_00);
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err |= __get_user(regs->UCreg_01, &sf->uc.uc_mcontext.regs.UCreg_01);
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err |= __get_user(regs->UCreg_02, &sf->uc.uc_mcontext.regs.UCreg_02);
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err |= __get_user(regs->UCreg_03, &sf->uc.uc_mcontext.regs.UCreg_03);
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err |= __get_user(regs->UCreg_04, &sf->uc.uc_mcontext.regs.UCreg_04);
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err |= __get_user(regs->UCreg_05, &sf->uc.uc_mcontext.regs.UCreg_05);
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err |= __get_user(regs->UCreg_06, &sf->uc.uc_mcontext.regs.UCreg_06);
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err |= __get_user(regs->UCreg_07, &sf->uc.uc_mcontext.regs.UCreg_07);
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err |= __get_user(regs->UCreg_08, &sf->uc.uc_mcontext.regs.UCreg_08);
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err |= __get_user(regs->UCreg_09, &sf->uc.uc_mcontext.regs.UCreg_09);
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err |= __get_user(regs->UCreg_10, &sf->uc.uc_mcontext.regs.UCreg_10);
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err |= __get_user(regs->UCreg_11, &sf->uc.uc_mcontext.regs.UCreg_11);
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err |= __get_user(regs->UCreg_12, &sf->uc.uc_mcontext.regs.UCreg_12);
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err |= __get_user(regs->UCreg_13, &sf->uc.uc_mcontext.regs.UCreg_13);
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err |= __get_user(regs->UCreg_14, &sf->uc.uc_mcontext.regs.UCreg_14);
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err |= __get_user(regs->UCreg_15, &sf->uc.uc_mcontext.regs.UCreg_15);
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err |= __get_user(regs->UCreg_16, &sf->uc.uc_mcontext.regs.UCreg_16);
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err |= __get_user(regs->UCreg_17, &sf->uc.uc_mcontext.regs.UCreg_17);
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err |= __get_user(regs->UCreg_18, &sf->uc.uc_mcontext.regs.UCreg_18);
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err |= __get_user(regs->UCreg_19, &sf->uc.uc_mcontext.regs.UCreg_19);
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err |= __get_user(regs->UCreg_20, &sf->uc.uc_mcontext.regs.UCreg_20);
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err |= __get_user(regs->UCreg_21, &sf->uc.uc_mcontext.regs.UCreg_21);
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err |= __get_user(regs->UCreg_22, &sf->uc.uc_mcontext.regs.UCreg_22);
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err |= __get_user(regs->UCreg_23, &sf->uc.uc_mcontext.regs.UCreg_23);
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err |= __get_user(regs->UCreg_24, &sf->uc.uc_mcontext.regs.UCreg_24);
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err |= __get_user(regs->UCreg_25, &sf->uc.uc_mcontext.regs.UCreg_25);
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err |= __get_user(regs->UCreg_26, &sf->uc.uc_mcontext.regs.UCreg_26);
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err |= __get_user(regs->UCreg_fp, &sf->uc.uc_mcontext.regs.UCreg_fp);
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err |= __get_user(regs->UCreg_ip, &sf->uc.uc_mcontext.regs.UCreg_ip);
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err |= __get_user(regs->UCreg_sp, &sf->uc.uc_mcontext.regs.UCreg_sp);
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err |= __get_user(regs->UCreg_lr, &sf->uc.uc_mcontext.regs.UCreg_lr);
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err |= __get_user(regs->UCreg_pc, &sf->uc.uc_mcontext.regs.UCreg_pc);
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err |= __get_user(regs->UCreg_asr, &sf->uc.uc_mcontext.regs.UCreg_asr);
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err |= !valid_user_regs(regs);
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return err;
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}
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asmlinkage int __sys_rt_sigreturn(struct pt_regs *regs)
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{
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struct rt_sigframe __user *frame;
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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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/*
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* Since we stacked the signal on a 64-bit boundary,
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* then 'sp' should be word aligned here. If it's
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* not, then the user is trying to mess with us.
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*/
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if (regs->UCreg_sp & 7)
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goto badframe;
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frame = (struct rt_sigframe __user *)regs->UCreg_sp;
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if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
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goto badframe;
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if (restore_sigframe(regs, &frame->sig))
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goto badframe;
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if (restore_altstack(&frame->sig.uc.uc_stack))
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goto badframe;
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return regs->UCreg_00;
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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 int setup_sigframe(struct sigframe __user *sf, struct pt_regs *regs,
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sigset_t *set)
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{
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int err = 0;
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err |= __put_user(regs->UCreg_00, &sf->uc.uc_mcontext.regs.UCreg_00);
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err |= __put_user(regs->UCreg_01, &sf->uc.uc_mcontext.regs.UCreg_01);
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err |= __put_user(regs->UCreg_02, &sf->uc.uc_mcontext.regs.UCreg_02);
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err |= __put_user(regs->UCreg_03, &sf->uc.uc_mcontext.regs.UCreg_03);
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err |= __put_user(regs->UCreg_04, &sf->uc.uc_mcontext.regs.UCreg_04);
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err |= __put_user(regs->UCreg_05, &sf->uc.uc_mcontext.regs.UCreg_05);
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err |= __put_user(regs->UCreg_06, &sf->uc.uc_mcontext.regs.UCreg_06);
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err |= __put_user(regs->UCreg_07, &sf->uc.uc_mcontext.regs.UCreg_07);
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err |= __put_user(regs->UCreg_08, &sf->uc.uc_mcontext.regs.UCreg_08);
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err |= __put_user(regs->UCreg_09, &sf->uc.uc_mcontext.regs.UCreg_09);
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err |= __put_user(regs->UCreg_10, &sf->uc.uc_mcontext.regs.UCreg_10);
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err |= __put_user(regs->UCreg_11, &sf->uc.uc_mcontext.regs.UCreg_11);
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err |= __put_user(regs->UCreg_12, &sf->uc.uc_mcontext.regs.UCreg_12);
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err |= __put_user(regs->UCreg_13, &sf->uc.uc_mcontext.regs.UCreg_13);
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err |= __put_user(regs->UCreg_14, &sf->uc.uc_mcontext.regs.UCreg_14);
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err |= __put_user(regs->UCreg_15, &sf->uc.uc_mcontext.regs.UCreg_15);
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err |= __put_user(regs->UCreg_16, &sf->uc.uc_mcontext.regs.UCreg_16);
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err |= __put_user(regs->UCreg_17, &sf->uc.uc_mcontext.regs.UCreg_17);
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err |= __put_user(regs->UCreg_18, &sf->uc.uc_mcontext.regs.UCreg_18);
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err |= __put_user(regs->UCreg_19, &sf->uc.uc_mcontext.regs.UCreg_19);
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err |= __put_user(regs->UCreg_20, &sf->uc.uc_mcontext.regs.UCreg_20);
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err |= __put_user(regs->UCreg_21, &sf->uc.uc_mcontext.regs.UCreg_21);
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err |= __put_user(regs->UCreg_22, &sf->uc.uc_mcontext.regs.UCreg_22);
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err |= __put_user(regs->UCreg_23, &sf->uc.uc_mcontext.regs.UCreg_23);
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err |= __put_user(regs->UCreg_24, &sf->uc.uc_mcontext.regs.UCreg_24);
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err |= __put_user(regs->UCreg_25, &sf->uc.uc_mcontext.regs.UCreg_25);
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err |= __put_user(regs->UCreg_26, &sf->uc.uc_mcontext.regs.UCreg_26);
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err |= __put_user(regs->UCreg_fp, &sf->uc.uc_mcontext.regs.UCreg_fp);
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err |= __put_user(regs->UCreg_ip, &sf->uc.uc_mcontext.regs.UCreg_ip);
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err |= __put_user(regs->UCreg_sp, &sf->uc.uc_mcontext.regs.UCreg_sp);
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err |= __put_user(regs->UCreg_lr, &sf->uc.uc_mcontext.regs.UCreg_lr);
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err |= __put_user(regs->UCreg_pc, &sf->uc.uc_mcontext.regs.UCreg_pc);
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err |= __put_user(regs->UCreg_asr, &sf->uc.uc_mcontext.regs.UCreg_asr);
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err |= __put_user(current->thread.trap_no,
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&sf->uc.uc_mcontext.trap_no);
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err |= __put_user(current->thread.error_code,
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&sf->uc.uc_mcontext.error_code);
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err |= __put_user(current->thread.address,
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&sf->uc.uc_mcontext.fault_address);
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err |= __put_user(set->sig[0], &sf->uc.uc_mcontext.oldmask);
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err |= __copy_to_user(&sf->uc.uc_sigmask, set, sizeof(*set));
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return err;
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}
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static inline void __user *get_sigframe(struct k_sigaction *ka,
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struct pt_regs *regs, int framesize)
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{
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unsigned long sp = regs->UCreg_sp;
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void __user *frame;
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/*
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* This is the X/Open sanctioned signal stack switching.
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*/
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if ((ka->sa.sa_flags & SA_ONSTACK) && !sas_ss_flags(sp))
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sp = current->sas_ss_sp + current->sas_ss_size;
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/*
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* ATPCS B01 mandates 8-byte alignment
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*/
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frame = (void __user *)((sp - framesize) & ~7);
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/*
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* Check that we can actually write to the signal frame.
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*/
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if (!access_ok(VERIFY_WRITE, frame, framesize))
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frame = NULL;
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return frame;
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}
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static int setup_return(struct pt_regs *regs, struct k_sigaction *ka,
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unsigned long __user *rc, void __user *frame, int usig)
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{
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unsigned long handler = (unsigned long)ka->sa.sa_handler;
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unsigned long retcode;
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unsigned long asr = regs->UCreg_asr & ~PSR_f;
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unsigned int idx = 0;
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if (ka->sa.sa_flags & SA_SIGINFO)
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idx += 1;
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if (__put_user(sigreturn_codes[idx], rc) ||
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__put_user(sigreturn_codes[idx+1], rc+1))
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return 1;
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retcode = KERN_SIGRETURN_CODE + (idx << 2);
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regs->UCreg_00 = usig;
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regs->UCreg_sp = (unsigned long)frame;
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regs->UCreg_lr = retcode;
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regs->UCreg_pc = handler;
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regs->UCreg_asr = asr;
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return 0;
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}
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static int setup_frame(struct ksignal *ksig, sigset_t *set,
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struct pt_regs *regs)
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{
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struct sigframe __user *frame = get_sigframe(&ksig->ka, regs, sizeof(*frame));
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int err = 0;
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if (!frame)
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return 1;
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/*
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* Set uc.uc_flags to a value which sc.trap_no would never have.
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*/
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err |= __put_user(0x5ac3c35a, &frame->uc.uc_flags);
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err |= setup_sigframe(frame, regs, set);
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if (err == 0)
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err |= setup_return(regs, &ksig->ka, frame->retcode, frame,
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ksig->sig);
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return err;
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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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struct rt_sigframe __user *frame =
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get_sigframe(&ksig->ka, regs, sizeof(*frame));
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int err = 0;
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if (!frame)
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return 1;
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err |= copy_siginfo_to_user(&frame->info, &ksig->info);
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err |= __put_user(0, &frame->sig.uc.uc_flags);
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err |= __put_user(NULL, &frame->sig.uc.uc_link);
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err |= __save_altstack(&frame->sig.uc.uc_stack, regs->UCreg_sp);
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err |= setup_sigframe(&frame->sig, regs, set);
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if (err == 0)
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err |= setup_return(regs, &ksig->ka, frame->sig.retcode, frame,
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ksig->sig);
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if (err == 0) {
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/*
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* For realtime signals we must also set the second and third
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* arguments for the signal handler.
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*/
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regs->UCreg_01 = (unsigned long)&frame->info;
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regs->UCreg_02 = (unsigned long)&frame->sig.uc;
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}
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return err;
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}
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static inline void setup_syscall_restart(struct pt_regs *regs)
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{
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regs->UCreg_00 = regs->UCreg_ORIG_00;
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regs->UCreg_pc -= 4;
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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 void handle_signal(struct ksignal *ksig, struct pt_regs *regs,
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int syscall)
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{
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struct thread_info *thread = current_thread_info();
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sigset_t *oldset = sigmask_to_save();
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int usig = ksig->sig;
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int ret;
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/*
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* If we were from a system call, check for system call restarting...
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*/
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if (syscall) {
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switch (regs->UCreg_00) {
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case -ERESTART_RESTARTBLOCK:
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case -ERESTARTNOHAND:
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regs->UCreg_00 = -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->UCreg_00 = -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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setup_syscall_restart(regs);
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}
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}
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/*
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* Set up the stack frame
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*/
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if (ksig->ka.sa.sa_flags & SA_SIGINFO)
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ret = setup_rt_frame(ksig, oldset, regs);
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else
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ret = setup_frame(ksig, oldset, regs);
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/*
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* Check that the resulting registers are actually sane.
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*/
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ret |= !valid_user_regs(regs);
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signal_setup_done(ret, ksig, 0);
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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 that
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* the kernel can handle, and then we build all the user-level signal handling
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* stack-frames in one go after that.
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*/
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static void do_signal(struct pt_regs *regs, int syscall)
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{
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struct ksignal ksig;
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/*
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* We want the common case to go fast, which
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* is why we may in certain cases get here from
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* kernel mode. Just return without doing anything
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* if so.
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*/
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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, syscall);
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return;
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}
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/*
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* No signal to deliver to the process - restart the syscall.
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*/
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if (syscall) {
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if (regs->UCreg_00 == -ERESTART_RESTARTBLOCK) {
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u32 __user *usp;
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regs->UCreg_sp -= 4;
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usp = (u32 __user *)regs->UCreg_sp;
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if (put_user(regs->UCreg_pc, usp) == 0) {
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regs->UCreg_pc = KERN_RESTART_CODE;
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} else {
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regs->UCreg_sp += 4;
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force_sigsegv(0, current);
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}
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}
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if (regs->UCreg_00 == -ERESTARTNOHAND ||
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regs->UCreg_00 == -ERESTARTSYS ||
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regs->UCreg_00 == -ERESTARTNOINTR) {
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setup_syscall_restart(regs);
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}
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}
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/* If there's no signal to deliver, we just put the saved
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* sigmask back.
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*/
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restore_saved_sigmask();
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}
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asmlinkage void do_notify_resume(struct pt_regs *regs,
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unsigned int thread_flags, int syscall)
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{
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if (thread_flags & _TIF_SIGPENDING)
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do_signal(regs, syscall);
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if (thread_flags & _TIF_NOTIFY_RESUME) {
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clear_thread_flag(TIF_NOTIFY_RESUME);
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tracehook_notify_resume(regs);
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}
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}
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/*
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* Copy signal return handlers into the vector page, and
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* set sigreturn to be a pointer to these.
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*/
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void __init early_signal_init(void)
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{
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memcpy((void *)kuser_vecpage_to_vectors(KERN_SIGRETURN_CODE),
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sigreturn_codes, sizeof(sigreturn_codes));
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memcpy((void *)kuser_vecpage_to_vectors(KERN_RESTART_CODE),
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syscall_restart_code, sizeof(syscall_restart_code));
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/* Need not to flush icache, since early_trap_init will do it last. */
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}
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