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df561f6688
Replace the existing /* fall through */ comments and its variants with the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary fall-through markings when it is the case. [1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
293 lines
7.3 KiB
C
293 lines
7.3 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* linux/kernel/compat.c
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*
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* Kernel compatibililty routines for e.g. 32 bit syscall support
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* on 64 bit kernels.
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*
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* Copyright (C) 2002-2003 Stephen Rothwell, IBM Corporation
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*/
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#include <linux/linkage.h>
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#include <linux/compat.h>
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#include <linux/errno.h>
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#include <linux/time.h>
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#include <linux/signal.h>
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#include <linux/sched.h> /* for MAX_SCHEDULE_TIMEOUT */
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#include <linux/syscalls.h>
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#include <linux/unistd.h>
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#include <linux/security.h>
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#include <linux/export.h>
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#include <linux/migrate.h>
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#include <linux/posix-timers.h>
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#include <linux/times.h>
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#include <linux/ptrace.h>
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#include <linux/gfp.h>
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#include <linux/uaccess.h>
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#ifdef __ARCH_WANT_SYS_SIGPROCMASK
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/*
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* sys_sigprocmask SIG_SETMASK sets the first (compat) word of the
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* blocked set of signals to the supplied signal set
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*/
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static inline void compat_sig_setmask(sigset_t *blocked, compat_sigset_word set)
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{
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memcpy(blocked->sig, &set, sizeof(set));
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}
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COMPAT_SYSCALL_DEFINE3(sigprocmask, int, how,
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compat_old_sigset_t __user *, nset,
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compat_old_sigset_t __user *, oset)
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{
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old_sigset_t old_set, new_set;
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sigset_t new_blocked;
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old_set = current->blocked.sig[0];
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if (nset) {
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if (get_user(new_set, nset))
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return -EFAULT;
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new_set &= ~(sigmask(SIGKILL) | sigmask(SIGSTOP));
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new_blocked = current->blocked;
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switch (how) {
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case SIG_BLOCK:
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sigaddsetmask(&new_blocked, new_set);
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break;
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case SIG_UNBLOCK:
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sigdelsetmask(&new_blocked, new_set);
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break;
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case SIG_SETMASK:
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compat_sig_setmask(&new_blocked, new_set);
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break;
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default:
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return -EINVAL;
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}
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set_current_blocked(&new_blocked);
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}
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if (oset) {
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if (put_user(old_set, oset))
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return -EFAULT;
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}
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return 0;
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}
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#endif
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int put_compat_rusage(const struct rusage *r, struct compat_rusage __user *ru)
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{
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struct compat_rusage r32;
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memset(&r32, 0, sizeof(r32));
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r32.ru_utime.tv_sec = r->ru_utime.tv_sec;
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r32.ru_utime.tv_usec = r->ru_utime.tv_usec;
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r32.ru_stime.tv_sec = r->ru_stime.tv_sec;
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r32.ru_stime.tv_usec = r->ru_stime.tv_usec;
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r32.ru_maxrss = r->ru_maxrss;
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r32.ru_ixrss = r->ru_ixrss;
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r32.ru_idrss = r->ru_idrss;
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r32.ru_isrss = r->ru_isrss;
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r32.ru_minflt = r->ru_minflt;
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r32.ru_majflt = r->ru_majflt;
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r32.ru_nswap = r->ru_nswap;
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r32.ru_inblock = r->ru_inblock;
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r32.ru_oublock = r->ru_oublock;
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r32.ru_msgsnd = r->ru_msgsnd;
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r32.ru_msgrcv = r->ru_msgrcv;
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r32.ru_nsignals = r->ru_nsignals;
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r32.ru_nvcsw = r->ru_nvcsw;
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r32.ru_nivcsw = r->ru_nivcsw;
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if (copy_to_user(ru, &r32, sizeof(r32)))
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return -EFAULT;
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return 0;
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}
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static int compat_get_user_cpu_mask(compat_ulong_t __user *user_mask_ptr,
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unsigned len, struct cpumask *new_mask)
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{
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unsigned long *k;
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if (len < cpumask_size())
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memset(new_mask, 0, cpumask_size());
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else if (len > cpumask_size())
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len = cpumask_size();
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k = cpumask_bits(new_mask);
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return compat_get_bitmap(k, user_mask_ptr, len * 8);
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}
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COMPAT_SYSCALL_DEFINE3(sched_setaffinity, compat_pid_t, pid,
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unsigned int, len,
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compat_ulong_t __user *, user_mask_ptr)
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{
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cpumask_var_t new_mask;
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int retval;
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if (!alloc_cpumask_var(&new_mask, GFP_KERNEL))
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return -ENOMEM;
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retval = compat_get_user_cpu_mask(user_mask_ptr, len, new_mask);
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if (retval)
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goto out;
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retval = sched_setaffinity(pid, new_mask);
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out:
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free_cpumask_var(new_mask);
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return retval;
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}
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COMPAT_SYSCALL_DEFINE3(sched_getaffinity, compat_pid_t, pid, unsigned int, len,
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compat_ulong_t __user *, user_mask_ptr)
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{
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int ret;
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cpumask_var_t mask;
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if ((len * BITS_PER_BYTE) < nr_cpu_ids)
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return -EINVAL;
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if (len & (sizeof(compat_ulong_t)-1))
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return -EINVAL;
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if (!alloc_cpumask_var(&mask, GFP_KERNEL))
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return -ENOMEM;
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ret = sched_getaffinity(pid, mask);
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if (ret == 0) {
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unsigned int retlen = min(len, cpumask_size());
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if (compat_put_bitmap(user_mask_ptr, cpumask_bits(mask), retlen * 8))
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ret = -EFAULT;
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else
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ret = retlen;
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}
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free_cpumask_var(mask);
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return ret;
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}
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/*
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* We currently only need the following fields from the sigevent
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* structure: sigev_value, sigev_signo, sig_notify and (sometimes
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* sigev_notify_thread_id). The others are handled in user mode.
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* We also assume that copying sigev_value.sival_int is sufficient
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* to keep all the bits of sigev_value.sival_ptr intact.
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*/
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int get_compat_sigevent(struct sigevent *event,
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const struct compat_sigevent __user *u_event)
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{
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memset(event, 0, sizeof(*event));
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return (!access_ok(u_event, sizeof(*u_event)) ||
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__get_user(event->sigev_value.sival_int,
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&u_event->sigev_value.sival_int) ||
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__get_user(event->sigev_signo, &u_event->sigev_signo) ||
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__get_user(event->sigev_notify, &u_event->sigev_notify) ||
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__get_user(event->sigev_notify_thread_id,
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&u_event->sigev_notify_thread_id))
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? -EFAULT : 0;
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}
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long compat_get_bitmap(unsigned long *mask, const compat_ulong_t __user *umask,
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unsigned long bitmap_size)
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{
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unsigned long nr_compat_longs;
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/* align bitmap up to nearest compat_long_t boundary */
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bitmap_size = ALIGN(bitmap_size, BITS_PER_COMPAT_LONG);
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nr_compat_longs = BITS_TO_COMPAT_LONGS(bitmap_size);
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if (!user_read_access_begin(umask, bitmap_size / 8))
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return -EFAULT;
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while (nr_compat_longs > 1) {
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compat_ulong_t l1, l2;
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unsafe_get_user(l1, umask++, Efault);
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unsafe_get_user(l2, umask++, Efault);
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*mask++ = ((unsigned long)l2 << BITS_PER_COMPAT_LONG) | l1;
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nr_compat_longs -= 2;
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}
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if (nr_compat_longs)
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unsafe_get_user(*mask, umask++, Efault);
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user_read_access_end();
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return 0;
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Efault:
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user_read_access_end();
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return -EFAULT;
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}
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long compat_put_bitmap(compat_ulong_t __user *umask, unsigned long *mask,
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unsigned long bitmap_size)
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{
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unsigned long nr_compat_longs;
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/* align bitmap up to nearest compat_long_t boundary */
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bitmap_size = ALIGN(bitmap_size, BITS_PER_COMPAT_LONG);
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nr_compat_longs = BITS_TO_COMPAT_LONGS(bitmap_size);
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if (!user_write_access_begin(umask, bitmap_size / 8))
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return -EFAULT;
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while (nr_compat_longs > 1) {
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unsigned long m = *mask++;
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unsafe_put_user((compat_ulong_t)m, umask++, Efault);
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unsafe_put_user(m >> BITS_PER_COMPAT_LONG, umask++, Efault);
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nr_compat_longs -= 2;
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}
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if (nr_compat_longs)
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unsafe_put_user((compat_ulong_t)*mask, umask++, Efault);
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user_write_access_end();
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return 0;
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Efault:
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user_write_access_end();
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return -EFAULT;
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}
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int
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get_compat_sigset(sigset_t *set, const compat_sigset_t __user *compat)
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{
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#ifdef __BIG_ENDIAN
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compat_sigset_t v;
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if (copy_from_user(&v, compat, sizeof(compat_sigset_t)))
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return -EFAULT;
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switch (_NSIG_WORDS) {
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case 4: set->sig[3] = v.sig[6] | (((long)v.sig[7]) << 32 );
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fallthrough;
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case 3: set->sig[2] = v.sig[4] | (((long)v.sig[5]) << 32 );
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fallthrough;
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case 2: set->sig[1] = v.sig[2] | (((long)v.sig[3]) << 32 );
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fallthrough;
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case 1: set->sig[0] = v.sig[0] | (((long)v.sig[1]) << 32 );
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}
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#else
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if (copy_from_user(set, compat, sizeof(compat_sigset_t)))
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return -EFAULT;
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#endif
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return 0;
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}
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EXPORT_SYMBOL_GPL(get_compat_sigset);
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/*
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* Allocate user-space memory for the duration of a single system call,
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* in order to marshall parameters inside a compat thunk.
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*/
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void __user *compat_alloc_user_space(unsigned long len)
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{
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void __user *ptr;
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/* If len would occupy more than half of the entire compat space... */
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if (unlikely(len > (((compat_uptr_t)~0) >> 1)))
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return NULL;
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ptr = arch_compat_alloc_user_space(len);
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if (unlikely(!access_ok(ptr, len)))
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return NULL;
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return ptr;
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}
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EXPORT_SYMBOL_GPL(compat_alloc_user_space);
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