init_once is called when an object doesn't come from the cache, and
hence needs initial clearing of certain members. While the whole
struct could get cleared by memset() in that case, a few of the cache
members are large enough that this may cause unnecessary overhead if
the caches used aren't large enough to satisfy the workload. For those
cases, some churn of kmalloc+kfree is to be expected.
Ensure that the 3 users that need clearing put the members they need
cleared at the start of the struct, and place an empty placeholder
'init' member so that the cache initialization knows how much to
clear.
Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
---
include/linux/io_uring/cmd.h | 3 ++-
include/linux/io_uring_types.h | 3 ++-
io_uring/alloc_cache.h | 30 +++++++++++++++++++++---------
io_uring/futex.c | 4 ++--
io_uring/io_uring.c | 13 ++++++++-----
io_uring/io_uring.h | 5 ++---
io_uring/net.c | 11 +----------
io_uring/net.h | 7 +++++--
io_uring/poll.c | 2 +-
io_uring/rw.c | 10 +---------
io_uring/rw.h | 5 ++++-
io_uring/uring_cmd.c | 10 +---------
12 files changed, 50 insertions(+), 53 deletions(-)
diff --git a/include/linux/io_uring/cmd.h b/include/linux/io_uring/cmd.h
index a3ce553413de..8d7746d9fd23 100644
--- a/include/linux/io_uring/cmd.h
+++ b/include/linux/io_uring/cmd.h
@@ -19,8 +19,9 @@ struct io_uring_cmd {
};
struct io_uring_cmd_data {
- struct io_uring_sqe sqes[2];
void *op_data;
+ int init[0];
+ struct io_uring_sqe sqes[2];
};
static inline const void *io_uring_sqe_cmd(const struct io_uring_sqe *sqe)
diff --git a/include/linux/io_uring_types.h b/include/linux/io_uring_types.h
index 623d8e798a11..3def525a1da3 100644
--- a/include/linux/io_uring_types.h
+++ b/include/linux/io_uring_types.h
@@ -222,7 +222,8 @@ struct io_alloc_cache {
void **entries;
unsigned int nr_cached;
unsigned int max_cached;
- size_t elem_size;
+ unsigned int elem_size;
+ unsigned int init_clear;
};
struct io_ring_ctx {
diff --git a/io_uring/alloc_cache.h b/io_uring/alloc_cache.h
index a3a8cfec32ce..f57d5e13cbbb 100644
--- a/io_uring/alloc_cache.h
+++ b/io_uring/alloc_cache.h
@@ -23,35 +23,47 @@ static inline void *io_alloc_cache_get(struct io_alloc_cache *cache)
if (cache->nr_cached) {
void *entry = cache->entries[--cache->nr_cached];
+ /*
+ * If KASAN is enabled, always clear the initial bytes that
+ * must be zeroed post alloc, in case any of them overlap
+ * with KASAN storage.
+ */
+#if defined(CONFIG_KASAN)
kasan_mempool_unpoison_object(entry, cache->elem_size);
+ if (cache->init_clear)
+ memset(entry, 0, cache->init_clear);
+#endif
return entry;
}
return NULL;
}
-static inline void *io_cache_alloc(struct io_alloc_cache *cache, gfp_t gfp,
- void (*init_once)(void *obj))
+static inline void *io_cache_alloc(struct io_alloc_cache *cache, gfp_t gfp)
{
- if (unlikely(!cache->nr_cached)) {
- void *obj = kmalloc(cache->elem_size, gfp);
+ void *obj;
- if (obj && init_once)
- init_once(obj);
+ obj = io_alloc_cache_get(cache);
+ if (obj)
return obj;
- }
- return io_alloc_cache_get(cache);
+
+ obj = kmalloc(cache->elem_size, gfp);
+ if (obj && cache->init_clear)
+ memset(obj, 0, cache->init_clear);
+ return obj;
}
/* returns false if the cache was initialized properly */
static inline bool io_alloc_cache_init(struct io_alloc_cache *cache,
- unsigned max_nr, size_t size)
+ unsigned max_nr, unsigned int size,
+ unsigned int init_bytes)
{
cache->entries = kvmalloc_array(max_nr, sizeof(void *), GFP_KERNEL);
if (cache->entries) {
cache->nr_cached = 0;
cache->max_cached = max_nr;
cache->elem_size = size;
+ cache->init_clear = init_bytes;
return false;
}
return true;
diff --git a/io_uring/futex.c b/io_uring/futex.c
index 30139cc150f2..3159a2b7eeca 100644
--- a/io_uring/futex.c
+++ b/io_uring/futex.c
@@ -36,7 +36,7 @@ struct io_futex_data {
bool io_futex_cache_init(struct io_ring_ctx *ctx)
{
return io_alloc_cache_init(&ctx->futex_cache, IO_FUTEX_ALLOC_CACHE_MAX,
- sizeof(struct io_futex_data));
+ sizeof(struct io_futex_data), 0);
}
void io_futex_cache_free(struct io_ring_ctx *ctx)
@@ -320,7 +320,7 @@ int io_futex_wait(struct io_kiocb *req, unsigned int issue_flags)
}
io_ring_submit_lock(ctx, issue_flags);
- ifd = io_cache_alloc(&ctx->futex_cache, GFP_NOWAIT, NULL);
+ ifd = io_cache_alloc(&ctx->futex_cache, GFP_NOWAIT);
if (!ifd) {
ret = -ENOMEM;
goto done_unlock;
diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c
index 7bfbc7c22367..7d38bdccbad8 100644
--- a/io_uring/io_uring.c
+++ b/io_uring/io_uring.c
@@ -315,16 +315,19 @@ static __cold struct io_ring_ctx *io_ring_ctx_alloc(struct io_uring_params *p)
INIT_LIST_HEAD(&ctx->cq_overflow_list);
INIT_LIST_HEAD(&ctx->io_buffers_cache);
ret = io_alloc_cache_init(&ctx->apoll_cache, IO_POLL_ALLOC_CACHE_MAX,
- sizeof(struct async_poll));
+ sizeof(struct async_poll), 0);
ret |= io_alloc_cache_init(&ctx->netmsg_cache, IO_ALLOC_CACHE_MAX,
- sizeof(struct io_async_msghdr));
+ sizeof(struct io_async_msghdr),
+ offsetof(struct io_async_msghdr, init));
ret |= io_alloc_cache_init(&ctx->rw_cache, IO_ALLOC_CACHE_MAX,
- sizeof(struct io_async_rw));
+ sizeof(struct io_async_rw),
+ offsetof(struct io_async_rw, init));
ret |= io_alloc_cache_init(&ctx->uring_cache, IO_ALLOC_CACHE_MAX,
- sizeof(struct io_uring_cmd_data));
+ sizeof(struct io_uring_cmd_data),
+ offsetof(struct io_uring_cmd_data, init));
spin_lock_init(&ctx->msg_lock);
ret |= io_alloc_cache_init(&ctx->msg_cache, IO_ALLOC_CACHE_MAX,
- sizeof(struct io_kiocb));
+ sizeof(struct io_kiocb), 0);
ret |= io_futex_cache_init(ctx);
if (ret)
goto free_ref;
diff --git a/io_uring/io_uring.h b/io_uring/io_uring.h
index f65e3f3ede51..67adbb3c1bf5 100644
--- a/io_uring/io_uring.h
+++ b/io_uring/io_uring.h
@@ -226,10 +226,9 @@ static inline void io_req_set_res(struct io_kiocb *req, s32 res, u32 cflags)
}
static inline void *io_uring_alloc_async_data(struct io_alloc_cache *cache,
- struct io_kiocb *req,
- void (*init_once)(void *obj))
+ struct io_kiocb *req)
{
- req->async_data = io_cache_alloc(cache, GFP_KERNEL, init_once);
+ req->async_data = io_cache_alloc(cache, GFP_KERNEL);
if (req->async_data)
req->flags |= REQ_F_ASYNC_DATA;
return req->async_data;
diff --git a/io_uring/net.c b/io_uring/net.c
index 85f55fbc25c9..35bec4680fcc 100644
--- a/io_uring/net.c
+++ b/io_uring/net.c
@@ -155,21 +155,12 @@ static void io_netmsg_recycle(struct io_kiocb *req, unsigned int issue_flags)
}
}
-static void io_msg_async_data_init(void *obj)
-{
- struct io_async_msghdr *hdr = (struct io_async_msghdr *)obj;
-
- hdr->free_iov = NULL;
- hdr->free_iov_nr = 0;
-}
-
static struct io_async_msghdr *io_msg_alloc_async(struct io_kiocb *req)
{
struct io_ring_ctx *ctx = req->ctx;
struct io_async_msghdr *hdr;
- hdr = io_uring_alloc_async_data(&ctx->netmsg_cache, req,
- io_msg_async_data_init);
+ hdr = io_uring_alloc_async_data(&ctx->netmsg_cache, req);
if (!hdr)
return NULL;
diff --git a/io_uring/net.h b/io_uring/net.h
index 52bfee05f06a..22a1a34bca09 100644
--- a/io_uring/net.h
+++ b/io_uring/net.h
@@ -5,16 +5,19 @@
struct io_async_msghdr {
#if defined(CONFIG_NET)
- struct iovec fast_iov;
- /* points to an allocated iov, if NULL we use fast_iov instead */
struct iovec *free_iov;
+ /* points to an allocated iov, if NULL we use fast_iov instead */
int free_iov_nr;
+ int init[0];
int namelen;
+ struct iovec fast_iov;
__kernel_size_t controllen;
__kernel_size_t payloadlen;
struct sockaddr __user *uaddr;
struct msghdr msg;
struct sockaddr_storage addr;
+#else
+ int init[0];
#endif
};
diff --git a/io_uring/poll.c b/io_uring/poll.c
index cc01c40b43d3..356474c66f32 100644
--- a/io_uring/poll.c
+++ b/io_uring/poll.c
@@ -650,7 +650,7 @@ static struct async_poll *io_req_alloc_apoll(struct io_kiocb *req,
kfree(apoll->double_poll);
} else {
if (!(issue_flags & IO_URING_F_UNLOCKED))
- apoll = io_cache_alloc(&ctx->apoll_cache, GFP_ATOMIC, NULL);
+ apoll = io_cache_alloc(&ctx->apoll_cache, GFP_ATOMIC);
else
apoll = kmalloc(sizeof(*apoll), GFP_ATOMIC);
if (!apoll)
diff --git a/io_uring/rw.c b/io_uring/rw.c
index a9a2733be842..0a0ad8a2bc0d 100644
--- a/io_uring/rw.c
+++ b/io_uring/rw.c
@@ -208,20 +208,12 @@ static void io_req_rw_cleanup(struct io_kiocb *req, unsigned int issue_flags)
}
}
-static void io_rw_async_data_init(void *obj)
-{
- struct io_async_rw *rw = (struct io_async_rw *)obj;
-
- rw->free_iovec = NULL;
- rw->bytes_done = 0;
-}
-
static int io_rw_alloc_async(struct io_kiocb *req)
{
struct io_ring_ctx *ctx = req->ctx;
struct io_async_rw *rw;
- rw = io_uring_alloc_async_data(&ctx->rw_cache, req, io_rw_async_data_init);
+ rw = io_uring_alloc_async_data(&ctx->rw_cache, req);
if (!rw)
return -ENOMEM;
if (rw->free_iovec) {
diff --git a/io_uring/rw.h b/io_uring/rw.h
index 2d7656bd268d..ab9e4df2504a 100644
--- a/io_uring/rw.h
+++ b/io_uring/rw.h
@@ -8,11 +8,14 @@ struct io_meta_state {
};
struct io_async_rw {
+ /* these must be cleared on initial alloc */
size_t bytes_done;
+ struct iovec *free_iovec;
+ int init[0];
+ /* rest persists over caching */
struct iov_iter iter;
struct iov_iter_state iter_state;
struct iovec fast_iov;
- struct iovec *free_iovec;
int free_iov_nr;
/* wpq is for buffered io, while meta fields are used with direct io */
union {
diff --git a/io_uring/uring_cmd.c b/io_uring/uring_cmd.c
index 6a63ec4b5445..0da7dc20eca6 100644
--- a/io_uring/uring_cmd.c
+++ b/io_uring/uring_cmd.c
@@ -168,21 +168,13 @@ void io_uring_cmd_done(struct io_uring_cmd *ioucmd, ssize_t ret, u64 res2,
}
EXPORT_SYMBOL_GPL(io_uring_cmd_done);
-static void io_uring_cmd_init_once(void *obj)
-{
- struct io_uring_cmd_data *data = obj;
-
- data->op_data = NULL;
-}
-
static int io_uring_cmd_prep_setup(struct io_kiocb *req,
const struct io_uring_sqe *sqe)
{
struct io_uring_cmd *ioucmd = io_kiocb_to_cmd(req, struct io_uring_cmd);
struct io_uring_cmd_data *cache;
- cache = io_uring_alloc_async_data(&req->ctx->uring_cache, req,
- io_uring_cmd_init_once);
+ cache = io_uring_alloc_async_data(&req->ctx->uring_cache, req);
if (!cache)
return -ENOMEM;
--
2.47.2
