From 7946c62e2d866890bbccdbd022087970ac8c36c7 Mon Sep 17 00:00:00 2001 From: =?utf8?q?=E9=BB=84=E6=B6=9B?= Date: Sat, 30 Jul 2011 23:09:43 +0800 Subject: [PATCH] Revert "futex: Restore one of the fast paths eliminated by 38d47c1b7075bd7ec3881141bb3629da58f88dab" This reverts commit 8d4c42afa543eda97ce1bc88f160ac1e0379ec52. --- kernel/futex.c | 32 -------------------------------- 1 file changed, 32 deletions(-) diff --git a/kernel/futex.c b/kernel/futex.c index 546e13300d3b..fb65e822fc41 100644 --- a/kernel/futex.c +++ b/kernel/futex.c @@ -222,7 +222,6 @@ get_futex_key(u32 __user *uaddr, int fshared, union futex_key *key, int rw) struct mm_struct *mm = current->mm; struct page *page; int err; - struct vm_area_struct *vma; /* * The futex address must be "naturally" aligned. @@ -248,37 +247,6 @@ get_futex_key(u32 __user *uaddr, int fshared, union futex_key *key, int rw) return 0; } - /* - * The futex is hashed differently depending on whether - * it's in a shared or private mapping. So check vma first. - */ - vma = find_extend_vma(mm, address); - if (unlikely(!vma)) - return -EFAULT; - - /* - * Permissions. - */ - if (unlikely((vma->vm_flags & (VM_IO|VM_READ)) != VM_READ)) - return (vma->vm_flags & VM_IO) ? -EPERM : -EACCES; - - /* - * Private mappings are handled in a simple way. - * - * NOTE: When userspace waits on a MAP_SHARED mapping, even if - * it's a read-only handle, it's expected that futexes attach to - * the object not the particular process. Therefore we use - * VM_MAYSHARE here, not VM_SHARED which is restricted to shared - * mappings of _writable_ handles. - */ - if (likely(!(vma->vm_flags & VM_MAYSHARE))) { - key->both.offset |= FUT_OFF_MMSHARED; /* reference taken on mm */ - key->private.mm = mm; - key->private.address = address; - get_futex_key_refs(key); - return 0; - } - again: err = get_user_pages_fast(address, 1, rw == VERIFY_WRITE, &page); if (err < 0) -- 2.34.1