Re: [PATCH] vhost-scsi: Depend on NET for memcpy_fromiovec
From: "Michael S. Tsirkin" <mst@redhat.com>
Date: 2013-05-23 07:31:04
Also in:
kvm, linux-next, lkml, virtualization
On Fri, May 17, 2013 at 09:12:39AM +0930, Rusty Russell wrote:
Joe Perches [off-list ref] writes:quoted
On Thu, 2013-05-16 at 13:04 +0930, Rusty Russell wrote:quoted
Asias He [off-list ref] writes:quoted
On Wed, May 15, 2013 at 02:47:53PM +0930, Rusty Russell wrote:[]quoted
quoted
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.[]quoted
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 + pagFascinating. 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.
Not in 3.10-rc2 yes - still plan to merge for 3.10?
quoted hunk ↗ jump to hunk
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 <redacted> Acked-by: David S. Miller <davem@davemloft.net> Acked-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Rusty Russell <redacted>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); #endifdiff --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. */