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select: switch compat_{get,put}_fd_set() to compat_{get,put}_bitmap()

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Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Al Viro 2017-06-04 03:24:26 -04:00
parent 7668b679c3
commit 464d62421c
1 changed files with 5 additions and 39 deletions
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44
fs/select.c
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@ -1161,59 +1161,25 @@ static
int compat_get_fd_set(unsigned long nr, compat_ulong_t __user *ufdset, int compat_get_fd_set(unsigned long nr, compat_ulong_t __user *ufdset,
unsigned long *fdset) unsigned long *fdset)
{ {
nr = DIV_ROUND_UP(nr, __COMPAT_NFDBITS);
if (ufdset) { if (ufdset) {
unsigned long odd; return compat_get_bitmap(fdset, ufdset, nr);
if (!access_ok(VERIFY_WRITE, ufdset, nr*sizeof(compat_ulong_t)))
return -EFAULT;
odd = nr & 1UL;
nr &= ~1UL;
while (nr) {
unsigned long h, l;
if (__get_user(l, ufdset) || __get_user(h, ufdset+1))
return -EFAULT;
ufdset += 2;
*fdset++ = h << 32 | l;
nr -= 2;
}
if (odd && __get_user(*fdset, ufdset))
return -EFAULT;
} else { } else {
/* Tricky, must clear full unsigned long in the /* Tricky, must clear full unsigned long in the
* kernel fdset at the end, this makes sure that * kernel fdset at the end, ALIGN makes sure that
* actually happens. * actually happens.
*/ */
memset(fdset, 0, ((nr + 1) & ~1)*sizeof(compat_ulong_t)); memset(fdset, 0, ALIGN(nr, BITS_PER_LONG));
}
return 0; return 0;
}
} }
static static
int compat_set_fd_set(unsigned long nr, compat_ulong_t __user *ufdset, int compat_set_fd_set(unsigned long nr, compat_ulong_t __user *ufdset,
unsigned long *fdset) unsigned long *fdset)
{ {
unsigned long odd;
nr = DIV_ROUND_UP(nr, __COMPAT_NFDBITS);
if (!ufdset) if (!ufdset)
return 0; return 0;
return compat_put_bitmap(ufdset, fdset, nr);
odd = nr & 1UL;
nr &= ~1UL;
while (nr) {
unsigned long h, l;
l = *fdset++;
h = l >> 32;
if (__put_user(l, ufdset) || __put_user(h, ufdset+1))
return -EFAULT;
ufdset += 2;
nr -= 2;
}
if (odd && __put_user(*fdset, ufdset))
return -EFAULT;
return 0;
} }