| Message ID | 1516874762-12046-1-git-send-email-baijiaju1990@gmail.com (mailing list archive) |
|---|---|
| State | Accepted |
| Delegated to: | Herbert Xu |
| Headers | show |
On Thu, Jan 25, 2018 at 06:06:02PM +0800, Jia-Ju Bai wrote: > After checking all possible call chains to crypto_report here, > my tool finds that crypto_report is never called in atomic context. > And crypto_report calls crypto_alg_match which calls down_read, > thus it proves again that crypto_report can call functions which may sleep. > Thus GFP_ATOMIC is not necessary, and it can be replaced with GFP_KERNEL. > > This is found by a static analysis tool named DCNS written by myself. > > Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com> Patch applied. Thanks.
diff --git a/crypto/crypto_user.c b/crypto/crypto_user.c index 0dbe2be7..23baef1 100644 --- a/crypto/crypto_user.c +++ b/crypto/crypto_user.c @@ -271,7 +271,7 @@ static int crypto_report(struct sk_buff *in_skb, struct nlmsghdr *in_nlh, return -ENOENT; err = -ENOMEM; - skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_ATOMIC); + skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL); if (!skb) goto drop_alg;
After checking all possible call chains to crypto_report here, my tool finds that crypto_report is never called in atomic context. And crypto_report calls crypto_alg_match which calls down_read, thus it proves again that crypto_report can call functions which may sleep. Thus GFP_ATOMIC is not necessary, and it can be replaced with GFP_KERNEL. This is found by a static analysis tool named DCNS written by myself. Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com> --- crypto/crypto_user.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)