| Message ID | 20220614091359.124571-1-dzm91@hust.edu.cn (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | fs: io_uring: remove NULL check before kfree | expand |
On Tue, Jun 14, 2022 at 5:14 PM Dongliang Mu <dzm91@hust.edu.cn> wrote: > > From: mudongliang <mudongliangabcd@gmail.com> > > kfree can handle NULL pointer as its argument. > According to coccinelle isnullfree check, remove NULL check > before kfree operation. > > Signed-off-by: mudongliang <mudongliangabcd@gmail.com> > --- > fs/io_uring.c | 15 +++++---------- > 1 file changed, 5 insertions(+), 10 deletions(-) > > diff --git a/fs/io_uring.c b/fs/io_uring.c > index 3aab4182fd89..bec47eae2a9b 100644 > --- a/fs/io_uring.c > +++ b/fs/io_uring.c > @@ -3159,8 +3159,7 @@ static void io_free_batch_list(struct io_ring_ctx *ctx, > if ((req->flags & REQ_F_POLLED) && req->apoll) { > struct async_poll *apoll = req->apoll; > > - if (apoll->double_poll) > - kfree(apoll->double_poll); > + kfree(apoll->double_poll); > list_add(&apoll->poll.wait.entry, > &ctx->apoll_cache); > req->flags &= ~REQ_F_POLLED; > @@ -4499,8 +4498,7 @@ static int io_read(struct io_kiocb *req, unsigned int issue_flags) > kiocb_done(req, ret, issue_flags); > out_free: > /* it's faster to check here then delegate to kfree */ I am feeling you are not on the right way. See the comment here. Thanks. > - if (iovec) > - kfree(iovec); > + kfree(iovec); > return 0; > } > > @@ -4602,8 +4600,7 @@ static int io_write(struct io_kiocb *req, unsigned int issue_flags) > } > out_free: > /* it's reportedly faster than delegating the null check to kfree() */ See here. > - if (iovec) > - kfree(iovec); > + kfree(iovec); > return ret; > } > > @@ -6227,8 +6224,7 @@ static int io_sendmsg(struct io_kiocb *req, unsigned int issue_flags) > req_set_fail(req); > } > /* fast path, check for non-NULL to avoid function call */ here. > - if (kmsg->free_iov) > - kfree(kmsg->free_iov); > + kfree(kmsg->free_iov); > req->flags &= ~REQ_F_NEED_CLEANUP; > if (ret >= 0) > ret += sr->done_io; > @@ -6481,8 +6477,7 @@ static int io_recvmsg(struct io_kiocb *req, unsigned int issue_flags) > } > > /* fast path, check for non-NULL to avoid function call */ And here. > - if (kmsg->free_iov) > - kfree(kmsg->free_iov); > + kfree(kmsg->free_iov); > req->flags &= ~REQ_F_NEED_CLEANUP; > if (ret >= 0) > ret += sr->done_io; > -- > 2.35.1 >
On Tue, Jun 14, 2022 at 5:26 PM Muchun Song <songmuchun@bytedance.com> wrote: > > On Tue, Jun 14, 2022 at 5:14 PM Dongliang Mu <dzm91@hust.edu.cn> wrote: > > > > From: mudongliang <mudongliangabcd@gmail.com> > > > > kfree can handle NULL pointer as its argument. > > According to coccinelle isnullfree check, remove NULL check > > before kfree operation. > > > > Signed-off-by: mudongliang <mudongliangabcd@gmail.com> > > --- > > fs/io_uring.c | 15 +++++---------- > > 1 file changed, 5 insertions(+), 10 deletions(-) > > > > diff --git a/fs/io_uring.c b/fs/io_uring.c > > index 3aab4182fd89..bec47eae2a9b 100644 > > --- a/fs/io_uring.c > > +++ b/fs/io_uring.c > > @@ -3159,8 +3159,7 @@ static void io_free_batch_list(struct io_ring_ctx *ctx, > > if ((req->flags & REQ_F_POLLED) && req->apoll) { > > struct async_poll *apoll = req->apoll; > > > > - if (apoll->double_poll) > > - kfree(apoll->double_poll); > > + kfree(apoll->double_poll); > > list_add(&apoll->poll.wait.entry, > > &ctx->apoll_cache); > > req->flags &= ~REQ_F_POLLED; > > @@ -4499,8 +4498,7 @@ static int io_read(struct io_kiocb *req, unsigned int issue_flags) > > kiocb_done(req, ret, issue_flags); > > out_free: > > /* it's faster to check here then delegate to kfree */ > > I am feeling you are not on the right way. See the comment > here. Thanks for your reply. I ignore them previously. Any method to make coccicheck ignore such cases? > > Thanks. > > > - if (iovec) > > - kfree(iovec); > > + kfree(iovec); > > return 0; > > } > > > > @@ -4602,8 +4600,7 @@ static int io_write(struct io_kiocb *req, unsigned int issue_flags) > > } > > out_free: > > /* it's reportedly faster than delegating the null check to kfree() */ > > See here. > > > - if (iovec) > > - kfree(iovec); > > + kfree(iovec); > > return ret; > > } > > > > @@ -6227,8 +6224,7 @@ static int io_sendmsg(struct io_kiocb *req, unsigned int issue_flags) > > req_set_fail(req); > > } > > /* fast path, check for non-NULL to avoid function call */ > > here. > > > - if (kmsg->free_iov) > > - kfree(kmsg->free_iov); > > + kfree(kmsg->free_iov); > > req->flags &= ~REQ_F_NEED_CLEANUP; > > if (ret >= 0) > > ret += sr->done_io; > > @@ -6481,8 +6477,7 @@ static int io_recvmsg(struct io_kiocb *req, unsigned int issue_flags) > > } > > > > /* fast path, check for non-NULL to avoid function call */ > > And here. > > > - if (kmsg->free_iov) > > - kfree(kmsg->free_iov); > > + kfree(kmsg->free_iov); > > req->flags &= ~REQ_F_NEED_CLEANUP; > > if (ret >= 0) > > ret += sr->done_io; > > -- > > 2.35.1 > >
diff --git a/fs/io_uring.c b/fs/io_uring.c index 3aab4182fd89..bec47eae2a9b 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -3159,8 +3159,7 @@ static void io_free_batch_list(struct io_ring_ctx *ctx, if ((req->flags & REQ_F_POLLED) && req->apoll) { struct async_poll *apoll = req->apoll; - if (apoll->double_poll) - kfree(apoll->double_poll); + kfree(apoll->double_poll); list_add(&apoll->poll.wait.entry, &ctx->apoll_cache); req->flags &= ~REQ_F_POLLED; @@ -4499,8 +4498,7 @@ static int io_read(struct io_kiocb *req, unsigned int issue_flags) kiocb_done(req, ret, issue_flags); out_free: /* it's faster to check here then delegate to kfree */ - if (iovec) - kfree(iovec); + kfree(iovec); return 0; } @@ -4602,8 +4600,7 @@ static int io_write(struct io_kiocb *req, unsigned int issue_flags) } out_free: /* it's reportedly faster than delegating the null check to kfree() */ - if (iovec) - kfree(iovec); + kfree(iovec); return ret; } @@ -6227,8 +6224,7 @@ static int io_sendmsg(struct io_kiocb *req, unsigned int issue_flags) req_set_fail(req); } /* fast path, check for non-NULL to avoid function call */ - if (kmsg->free_iov) - kfree(kmsg->free_iov); + kfree(kmsg->free_iov); req->flags &= ~REQ_F_NEED_CLEANUP; if (ret >= 0) ret += sr->done_io; @@ -6481,8 +6477,7 @@ static int io_recvmsg(struct io_kiocb *req, unsigned int issue_flags) } /* fast path, check for non-NULL to avoid function call */ - if (kmsg->free_iov) - kfree(kmsg->free_iov); + kfree(kmsg->free_iov); req->flags &= ~REQ_F_NEED_CLEANUP; if (ret >= 0) ret += sr->done_io;