lkml.org 
[lkml]   [2013]   [May]   [16]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
SubjectRe: [PATCH] vhost-scsi: Depend on NET for memcpy_fromiovec
Date
Joe Perches <joe@perches.com> writes:
> On Thu, 2013-05-16 at 13:04 +0930, Rusty Russell wrote:
>> Asias He <asias@redhat.com> writes:
>> > On Wed, May 15, 2013 at 02:47:53PM +0930, Rusty Russell wrote:
> []
>> > Other users are using memcpy_fromiovec and friends outside net. It seems
>> > a good idea to put it in a util library. e.g. crypto/algif_skcipher.c
>> > which also depends on NET for it.
>
> []
>> Subject: Hoist memcpy_fromiovec into lib/
>
> You'll need the "friends" memcpy_toiovec too.
>
> $ git grep -E \bmemcpy\w+iovec\w*"
> crypto/algif_hash.c: err = memcpy_toiovec(msg->msg_iov, ctx->result, len);
> crypto/algif_skcipher.c: err = memcpy_fromiovec(page_address(sg_page(sg)) +
> crypto/algif_skcipher.c: err = memcpy_fromiovec(page_address(sg_page(sg + i)),
> drivers/dma/iovlock.c:#include <net/tcp.h> /* for memcpy_toiovec */
> drivers/dma/iovlock.c: return memcpy_toiovec(iov, kdata, len);
> drivers/dma/iovlock.c: err = memcpy_toiovec(iov, vaddr + offset, len);
> drivers/isdn/mISDN/socket.c: if (memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len)) {
> drivers/misc/vmw_vmci/vmci_queue_pair.c: err = memcpy_fromiovec((u8 *)va + page_o
> drivers/misc/vmw_vmci/vmci_queue_pair.c: err = memcpy_toiovec(iov, (u8 *)va + pag

Fascinating. These all indirectly depend on NET, so there's no problem
at the moment. But it is a bit weird...

crypto/algif_hash.c: depends on CRYPTO_USER_API_HASH -> NET
crypto/algif_skcipher.c: depends on CRYPTO_USER_API_SKCIPHER -> NET
drivers/dma/iovlock.c: depends on NET_DMA -> NET
drivers/isdn/mISDN/socket.c: depends on MISDN -> ISDN -> NET
drivers/misc/vmw_vmci/vmci_queue_pair.c: depends on VMCI -> NET

Patch welcome.

Meanwhile, to avoid more bikeshedding I've put the patch I posted with
all acks in my fixes branch. One cycle through linux-next, then
straight to Linus.

Subject: Hoist memcpy_fromiovec into lib/

ERROR: "memcpy_fromiovec" [drivers/vhost/vhost_scsi.ko] undefined!

That function is only present with CONFIG_NET. Turns out that
crypto/algif_skcipher.c also uses that outside net, but it actually
needs sockets anyway.

socket.h already include uio.h, so no callers need updating.

Reported-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: David S. Miller <davem@davemloft.net>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

diff --git a/include/linux/socket.h b/include/linux/socket.h
index 428c37a..7266775 100644
--- a/include/linux/socket.h
+++ b/include/linux/socket.h
@@ -305,7 +305,6 @@ struct ucred {

extern void cred_to_ucred(struct pid *pid, const struct cred *cred, struct ucred *ucred);

-extern int memcpy_fromiovec(unsigned char *kdata, struct iovec *iov, int len);
extern int memcpy_fromiovecend(unsigned char *kdata, const struct iovec *iov,
int offset, int len);
extern int csum_partial_copy_fromiovecend(unsigned char *kdata,
diff --git a/include/linux/uio.h b/include/linux/uio.h
index 629aaf5..21628d3 100644
--- a/include/linux/uio.h
+++ b/include/linux/uio.h
@@ -35,4 +35,6 @@ static inline size_t iov_length(const struct iovec *iov, unsigned long nr_segs)
}

unsigned long iov_shorten(struct iovec *iov, unsigned long nr_segs, size_t to);
+
+int memcpy_fromiovec(unsigned char *kdata, struct iovec *iov, int len);
#endif
diff --git a/lib/Makefile b/lib/Makefile
index e9c52e1..2377211 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -9,7 +9,7 @@ endif

lib-y := ctype.o string.o vsprintf.o cmdline.o \
rbtree.o radix-tree.o dump_stack.o timerqueue.o\
- idr.o int_sqrt.o extable.o \
+ idr.o int_sqrt.o extable.o iovec.o \
sha1.o md5.o irq_regs.o reciprocal_div.o argv_split.o \
proportions.o flex_proportions.o prio_heap.o ratelimit.o show_mem.o \
is_single_threaded.o plist.o decompress.o kobject_uevent.o \
diff --git a/lib/iovec.c b/lib/iovec.c
new file mode 100644
index 0000000..632c5ea
--- /dev/null
+++ b/lib/iovec.c
@@ -0,0 +1,29 @@
+#include <linux/uaccess.h>
+#include <linux/export.h>
+#include <linux/uio.h>
+
+/*
+ * Copy iovec to kernel. Returns -EFAULT on error.
+ *
+ * Note: this modifies the original iovec.
+ */
+
+int memcpy_fromiovec(unsigned char *kdata, struct iovec *iov, int len)
+{
+ while (len > 0) {
+ if (iov->iov_len) {
+ int copy = min_t(unsigned int, len, iov->iov_len);
+ if (copy_from_user(kdata, iov->iov_base, copy))
+ return -EFAULT;
+ len -= copy;
+ kdata += copy;
+ iov->iov_base += copy;
+ iov->iov_len -= copy;
+ }
+ iov++;
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL(memcpy_fromiovec);
+
diff --git a/net/core/iovec.c b/net/core/iovec.c
index 7e7aeb0..d81257f 100644
--- a/net/core/iovec.c
+++ b/net/core/iovec.c
@@ -125,31 +125,6 @@ int memcpy_toiovecend(const struct iovec *iov, unsigned char *kdata,
EXPORT_SYMBOL(memcpy_toiovecend);

/*
- * Copy iovec to kernel. Returns -EFAULT on error.
- *
- * Note: this modifies the original iovec.
- */
-
-int memcpy_fromiovec(unsigned char *kdata, struct iovec *iov, int len)
-{
- while (len > 0) {
- if (iov->iov_len) {
- int copy = min_t(unsigned int, len, iov->iov_len);
- if (copy_from_user(kdata, iov->iov_base, copy))
- return -EFAULT;
- len -= copy;
- kdata += copy;
- iov->iov_base += copy;
- iov->iov_len -= copy;
- }
- iov++;
- }
-
- return 0;
-}
-EXPORT_SYMBOL(memcpy_fromiovec);
-
-/*
* Copy iovec from kernel. Returns -EFAULT on error.
*/



\
 
 \ /
  Last update: 2013-05-17 03:21    [W:0.364 / U:0.272 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site