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

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: 3f913fc5f9 ("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>
This commit is contained in:
Qi Zheng
2022-11-18 18:00:11 +08:00
committed by Andrew Morton
parent de1ccfb648
commit ea4452de2a
4 changed files with 28 additions and 11 deletions

View File

@@ -20,7 +20,6 @@ struct fault_attr {
atomic_t space;
unsigned long verbose;
bool task_filter;
bool no_warn;
unsigned long stacktrace_depth;
unsigned long require_start;
unsigned long require_end;
@@ -32,6 +31,10 @@ struct fault_attr {
struct dentry *dname;
};
enum fault_flags {
FAULT_NOWARN = 1 << 0,
};
#define FAULT_ATTR_INITIALIZER { \
.interval = 1, \
.times = ATOMIC_INIT(1), \
@@ -40,11 +43,11 @@ struct fault_attr {
.ratelimit_state = RATELIMIT_STATE_INIT_DISABLED, \
.verbose = 2, \
.dname = NULL, \
.no_warn = false, \
}
#define DECLARE_FAULT_ATTR(name) struct fault_attr name = FAULT_ATTR_INITIALIZER
int setup_fault_attr(struct fault_attr *attr, char *str);
bool should_fail_ex(struct fault_attr *attr, ssize_t size, int flags);
bool should_fail(struct fault_attr *attr, ssize_t size);
#ifdef CONFIG_FAULT_INJECTION_DEBUG_FS