mm: fix unexpected changes to {failslab|fail_page_alloc}.attr

mainline inclusion
from mainline-v6.1-rc7
commit ea4452de
category: bugfix
bugzilla: https://gitee.com/src-openeuler/kernel/issues/I69VVC
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=ea4452de2ae987342fadbdd2c044034e6480daad

--------------------------------

When we specify __GFP_NOWARN, we only expect that no warnings will be
issued for current caller.  But in the __should_failslab() and
__should_fail_alloc_page(), the local GFP flags alter the global
{failslab|fail_page_alloc}.attr, which is persistent and shared by all
tasks.  This is not what we expected, let's fix it.

[akpm@linux-foundation.org: unexport should_fail_ex()]
Link: https://lkml.kernel.org/r/20221118100011.2634-1-zhengqi.arch@bytedance.com


Fixes: 3f913fc5 ("mm: fix missing handler for __GFP_NOWARN")
Signed-off-by: Qi Zheng <zhengqi.arch@bytedance.com>
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Reviewed-by: Akinobu Mita <akinobu.mita@gmail.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Cc: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Conflict:
	mm/page_alloc.c

Signed-off-by: Ye Weihua <yeweihua4@huawei.com>
Reviewed-by: tong tiangen <tongtiangen@huawei.com>
Signed-off-by: Yongqiang Liu <liuyongqiang13@huawei.com>