From 464d62421cb8b2a6812dcb8c45184ff17b1bc5da Mon Sep 17 00:00:00 2001 From: Al Viro Date: Sun, 4 Jun 2017 03:24:26 -0400 Subject: [PATCH] select: switch compat_{get,put}_fd_set() to compat_{get,put}_bitmap() Signed-off-by: Al Viro --- fs/select.c | 44 +++++--------------------------------------- 1 file changed, 5 insertions(+), 39 deletions(-) diff --git a/fs/select.c b/fs/select.c index d6c652a31e99..806d2d92672f 100644 --- a/fs/select.c +++ b/fs/select.c @@ -1161,59 +1161,25 @@ static int compat_get_fd_set(unsigned long nr, compat_ulong_t __user *ufdset, unsigned long *fdset) { - nr = DIV_ROUND_UP(nr, __COMPAT_NFDBITS); if (ufdset) { - unsigned long odd; - - 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; + return compat_get_bitmap(fdset, ufdset, nr); } else { /* 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. */ - memset(fdset, 0, ((nr + 1) & ~1)*sizeof(compat_ulong_t)); + memset(fdset, 0, ALIGN(nr, BITS_PER_LONG)); + return 0; } - return 0; } static int compat_set_fd_set(unsigned long nr, compat_ulong_t __user *ufdset, unsigned long *fdset) { - unsigned long odd; - nr = DIV_ROUND_UP(nr, __COMPAT_NFDBITS); - if (!ufdset) return 0; - - 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; + return compat_put_bitmap(ufdset, fdset, nr); } -- 2.20.1