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![Al Viro](/assets/img/avatar_default.png)
Only 3 out of 63 do not. Renamed the current variant to __set_current_blocked(), added set_current_blocked() that will exclude unblockable signals, switched open-coded instances to it. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
428 lines
12 KiB
C
428 lines
12 KiB
C
/*
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* Copyright 2010 Tilera Corporation. All Rights Reserved.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation, version 2.
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*
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* This program is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
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* NON INFRINGEMENT. See the GNU General Public License for
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* more details.
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*/
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#include <linux/sched.h>
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#include <linux/mm.h>
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#include <linux/smp.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/unistd.h>
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#include <linux/stddef.h>
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#include <linux/personality.h>
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#include <linux/suspend.h>
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#include <linux/ptrace.h>
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#include <linux/elf.h>
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#include <linux/compat.h>
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#include <linux/syscalls.h>
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#include <linux/uaccess.h>
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#include <asm/processor.h>
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#include <asm/ucontext.h>
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#include <asm/sigframe.h>
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#include <asm/syscalls.h>
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#include <arch/interrupts.h>
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struct compat_sigaction {
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compat_uptr_t sa_handler;
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compat_ulong_t sa_flags;
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compat_uptr_t sa_restorer;
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sigset_t sa_mask __packed;
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};
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struct compat_sigaltstack {
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compat_uptr_t ss_sp;
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int ss_flags;
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compat_size_t ss_size;
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};
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struct compat_ucontext {
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compat_ulong_t uc_flags;
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compat_uptr_t uc_link;
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struct compat_sigaltstack uc_stack;
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struct sigcontext uc_mcontext;
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sigset_t uc_sigmask; /* mask last for extensibility */
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};
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#define COMPAT_SI_PAD_SIZE ((SI_MAX_SIZE - 3 * sizeof(int)) / sizeof(int))
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struct compat_siginfo {
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int si_signo;
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int si_errno;
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int si_code;
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union {
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int _pad[COMPAT_SI_PAD_SIZE];
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/* kill() */
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struct {
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unsigned int _pid; /* sender's pid */
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unsigned int _uid; /* sender's uid */
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} _kill;
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/* POSIX.1b timers */
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struct {
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compat_timer_t _tid; /* timer id */
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int _overrun; /* overrun count */
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compat_sigval_t _sigval; /* same as below */
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int _sys_private; /* not to be passed to user */
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int _overrun_incr; /* amount to add to overrun */
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} _timer;
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/* POSIX.1b signals */
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struct {
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unsigned int _pid; /* sender's pid */
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unsigned int _uid; /* sender's uid */
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compat_sigval_t _sigval;
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} _rt;
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/* SIGCHLD */
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struct {
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unsigned int _pid; /* which child */
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unsigned int _uid; /* sender's uid */
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int _status; /* exit code */
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compat_clock_t _utime;
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compat_clock_t _stime;
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} _sigchld;
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/* SIGILL, SIGFPE, SIGSEGV, SIGBUS */
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struct {
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unsigned int _addr; /* faulting insn/memory ref. */
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#ifdef __ARCH_SI_TRAPNO
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int _trapno; /* TRAP # which caused the signal */
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#endif
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} _sigfault;
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/* SIGPOLL */
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struct {
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int _band; /* POLL_IN, POLL_OUT, POLL_MSG */
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int _fd;
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} _sigpoll;
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} _sifields;
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};
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struct compat_rt_sigframe {
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unsigned char save_area[C_ABI_SAVE_AREA_SIZE]; /* caller save area */
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struct compat_siginfo info;
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struct compat_ucontext uc;
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};
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long compat_sys_rt_sigaction(int sig, struct compat_sigaction __user *act,
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struct compat_sigaction __user *oact,
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size_t sigsetsize)
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{
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struct k_sigaction new_sa, old_sa;
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int ret = -EINVAL;
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/* XXX: Don't preclude handling different sized sigset_t's. */
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if (sigsetsize != sizeof(sigset_t))
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goto out;
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if (act) {
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compat_uptr_t handler, restorer;
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if (!access_ok(VERIFY_READ, act, sizeof(*act)) ||
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__get_user(handler, &act->sa_handler) ||
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__get_user(new_sa.sa.sa_flags, &act->sa_flags) ||
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__get_user(restorer, &act->sa_restorer) ||
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__copy_from_user(&new_sa.sa.sa_mask, &act->sa_mask,
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sizeof(sigset_t)))
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return -EFAULT;
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new_sa.sa.sa_handler = compat_ptr(handler);
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new_sa.sa.sa_restorer = compat_ptr(restorer);
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}
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ret = do_sigaction(sig, act ? &new_sa : NULL, oact ? &old_sa : NULL);
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if (!ret && oact) {
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if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)) ||
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__put_user(ptr_to_compat(old_sa.sa.sa_handler),
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&oact->sa_handler) ||
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__put_user(ptr_to_compat(old_sa.sa.sa_restorer),
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&oact->sa_restorer) ||
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__put_user(old_sa.sa.sa_flags, &oact->sa_flags) ||
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__copy_to_user(&oact->sa_mask, &old_sa.sa.sa_mask,
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sizeof(sigset_t)))
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return -EFAULT;
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}
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out:
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return ret;
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}
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long compat_sys_rt_sigqueueinfo(int pid, int sig,
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struct compat_siginfo __user *uinfo)
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{
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siginfo_t info;
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int ret;
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mm_segment_t old_fs = get_fs();
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if (copy_siginfo_from_user32(&info, uinfo))
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return -EFAULT;
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set_fs(KERNEL_DS);
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ret = sys_rt_sigqueueinfo(pid, sig, (siginfo_t __force __user *)&info);
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set_fs(old_fs);
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return ret;
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}
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int copy_siginfo_to_user32(struct compat_siginfo __user *to, siginfo_t *from)
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{
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int err;
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if (!access_ok(VERIFY_WRITE, to, sizeof(struct compat_siginfo)))
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return -EFAULT;
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/* If you change siginfo_t structure, please make sure that
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this code is fixed accordingly.
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It should never copy any pad contained in the structure
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to avoid security leaks, but must copy the generic
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3 ints plus the relevant union member. */
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err = __put_user(from->si_signo, &to->si_signo);
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err |= __put_user(from->si_errno, &to->si_errno);
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err |= __put_user((short)from->si_code, &to->si_code);
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if (from->si_code < 0) {
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err |= __put_user(from->si_pid, &to->si_pid);
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err |= __put_user(from->si_uid, &to->si_uid);
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err |= __put_user(ptr_to_compat(from->si_ptr), &to->si_ptr);
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} else {
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/*
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* First 32bits of unions are always present:
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* si_pid === si_band === si_tid === si_addr(LS half)
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*/
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err |= __put_user(from->_sifields._pad[0],
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&to->_sifields._pad[0]);
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switch (from->si_code >> 16) {
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case __SI_FAULT >> 16:
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break;
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case __SI_CHLD >> 16:
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err |= __put_user(from->si_utime, &to->si_utime);
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err |= __put_user(from->si_stime, &to->si_stime);
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err |= __put_user(from->si_status, &to->si_status);
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/* FALL THROUGH */
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default:
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case __SI_KILL >> 16:
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err |= __put_user(from->si_uid, &to->si_uid);
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break;
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case __SI_POLL >> 16:
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err |= __put_user(from->si_fd, &to->si_fd);
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break;
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case __SI_TIMER >> 16:
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err |= __put_user(from->si_overrun, &to->si_overrun);
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err |= __put_user(ptr_to_compat(from->si_ptr),
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&to->si_ptr);
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break;
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/* This is not generated by the kernel as of now. */
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case __SI_RT >> 16:
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case __SI_MESGQ >> 16:
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err |= __put_user(from->si_uid, &to->si_uid);
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err |= __put_user(from->si_int, &to->si_int);
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break;
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}
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}
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return err;
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}
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int copy_siginfo_from_user32(siginfo_t *to, struct compat_siginfo __user *from)
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{
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int err;
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u32 ptr32;
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if (!access_ok(VERIFY_READ, from, sizeof(struct compat_siginfo)))
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return -EFAULT;
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err = __get_user(to->si_signo, &from->si_signo);
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err |= __get_user(to->si_errno, &from->si_errno);
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err |= __get_user(to->si_code, &from->si_code);
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err |= __get_user(to->si_pid, &from->si_pid);
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err |= __get_user(to->si_uid, &from->si_uid);
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err |= __get_user(ptr32, &from->si_ptr);
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to->si_ptr = compat_ptr(ptr32);
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return err;
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}
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long compat_sys_sigaltstack(const struct compat_sigaltstack __user *uss_ptr,
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struct compat_sigaltstack __user *uoss_ptr,
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struct pt_regs *regs)
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{
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stack_t uss, uoss;
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int ret;
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mm_segment_t seg;
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if (uss_ptr) {
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u32 ptr;
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memset(&uss, 0, sizeof(stack_t));
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if (!access_ok(VERIFY_READ, uss_ptr, sizeof(*uss_ptr)) ||
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__get_user(ptr, &uss_ptr->ss_sp) ||
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__get_user(uss.ss_flags, &uss_ptr->ss_flags) ||
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__get_user(uss.ss_size, &uss_ptr->ss_size))
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return -EFAULT;
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uss.ss_sp = compat_ptr(ptr);
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}
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seg = get_fs();
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set_fs(KERNEL_DS);
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ret = do_sigaltstack(uss_ptr ? (stack_t __user __force *)&uss : NULL,
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(stack_t __user __force *)&uoss,
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(unsigned long)compat_ptr(regs->sp));
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set_fs(seg);
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if (ret >= 0 && uoss_ptr) {
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if (!access_ok(VERIFY_WRITE, uoss_ptr, sizeof(*uoss_ptr)) ||
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__put_user(ptr_to_compat(uoss.ss_sp), &uoss_ptr->ss_sp) ||
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__put_user(uoss.ss_flags, &uoss_ptr->ss_flags) ||
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__put_user(uoss.ss_size, &uoss_ptr->ss_size))
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ret = -EFAULT;
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}
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return ret;
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}
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/* The assembly shim for this function arranges to ignore the return value. */
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long compat_sys_rt_sigreturn(struct pt_regs *regs)
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{
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struct compat_rt_sigframe __user *frame =
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(struct compat_rt_sigframe __user *) compat_ptr(regs->sp);
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sigset_t set;
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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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set_current_blocked(&set);
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if (restore_sigcontext(regs, &frame->uc.uc_mcontext))
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goto badframe;
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if (compat_sys_sigaltstack(&frame->uc.uc_stack, NULL, regs) != 0)
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goto badframe;
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return 0;
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badframe:
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signal_fault("bad sigreturn frame", regs, frame, 0);
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return 0;
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}
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/*
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* Determine which stack to use..
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*/
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static inline void __user *compat_get_sigframe(struct k_sigaction *ka,
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struct pt_regs *regs,
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size_t frame_size)
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{
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unsigned long sp;
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/* Default to using normal stack */
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sp = (unsigned long)compat_ptr(regs->sp);
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/*
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* If we are on the alternate signal stack and would overflow
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* it, don't. Return an always-bogus address instead so we
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* will die with SIGSEGV.
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*/
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if (on_sig_stack(sp) && !likely(on_sig_stack(sp - frame_size)))
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return (void __user __force *)-1UL;
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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 (sas_ss_flags(sp) == 0)
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sp = current->sas_ss_sp + current->sas_ss_size;
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}
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sp -= frame_size;
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/*
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* Align the stack pointer according to the TILE ABI,
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* i.e. so that on function entry (sp & 15) == 0.
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*/
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sp &= -16UL;
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return (void __user *) sp;
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}
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int compat_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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unsigned long restorer;
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struct compat_rt_sigframe __user *frame;
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int err = 0;
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int usig;
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frame = compat_get_sigframe(ka, regs, sizeof(*frame));
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if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
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goto give_sigsegv;
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usig = 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->signal_invmap[sig]
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: sig;
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/* Always write at least the signal number for the stack backtracer. */
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if (ka->sa.sa_flags & SA_SIGINFO) {
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/* At sigreturn time, restore the callee-save registers too. */
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err |= copy_siginfo_to_user32(&frame->info, info);
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regs->flags |= PT_FLAGS_RESTORE_REGS;
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} else {
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err |= __put_user(info->si_signo, &frame->info.si_signo);
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}
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/* Create the ucontext. */
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err |= __clear_user(&frame->save_area, sizeof(frame->save_area));
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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 |= __put_user(ptr_to_compat((void *)(current->sas_ss_sp)),
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&frame->uc.uc_stack.ss_sp);
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err |= __put_user(sas_ss_flags(regs->sp),
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&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 |= 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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restorer = VDSO_BASE;
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if (ka->sa.sa_flags & SA_RESTORER)
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restorer = ptr_to_compat_reg(ka->sa.sa_restorer);
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/*
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* Set up registers for signal handler.
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* Registers that we don't modify keep the value they had from
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* user-space at the time we took the signal.
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* We always pass siginfo and mcontext, regardless of SA_SIGINFO,
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* since some things rely on this (e.g. glibc's debug/segfault.c).
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*/
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regs->pc = ptr_to_compat_reg(ka->sa.sa_handler);
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regs->ex1 = PL_ICS_EX1(USER_PL, 1); /* set crit sec in handler */
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regs->sp = ptr_to_compat_reg(frame);
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regs->lr = restorer;
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regs->regs[0] = (unsigned long) usig;
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regs->regs[1] = ptr_to_compat_reg(&frame->info);
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regs->regs[2] = ptr_to_compat_reg(&frame->uc);
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regs->flags |= PT_FLAGS_CALLER_SAVES;
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/*
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* Notify any tracer that was single-stepping it.
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* The tracer may want to single-step inside the
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* handler too.
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*/
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if (test_thread_flag(TIF_SINGLESTEP))
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ptrace_notify(SIGTRAP);
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return 0;
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give_sigsegv:
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signal_fault("bad setup frame", regs, frame, sig);
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return -EFAULT;
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}
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