| Message ID | 744974f1-d9b3-9fc1-621d-f4b5d3e806b6@spiers.me (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Fri, Mar 9, 2018 at 9:14 PM, Kyle Spiers <kyle@spiers.me> wrote: > From 4198ebe2e8058ff676d8e2f993d8806d6ca29c11 Mon Sep 17 00:00:00 2001 > From: Kyle Spiers <kyle@spiers.me> > Date: Fri, 9 Mar 2018 12:34:15 -0800 > Subject: [PATCH] rbd: Remove VLA usage > > As part of the effort to remove VLAs from the kernel[1], this moves > the literal values into the stack array calculation instead of using a > variable for the sizing. The resulting size can be found from > sizeof(buf). > > [1] https://lkml.org/lkml/2018/3/7/621 > > Signed-off-by: Kyle Spiers <kyle@spiers.me> Thanks! Reviewed-by: Kees Cook <keescook@chromium.org> -Kees > > --- > drivers/block/rbd.c | 8 ++++---- > 1 file changed, 4 insertions(+), 4 deletions(-) > > diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c > index 8e40da0..0e94e1f 100644 > --- a/drivers/block/rbd.c > +++ b/drivers/block/rbd.c > @@ -3100,8 +3100,8 @@ static int __rbd_notify_op_lock(struct rbd_device > *rbd_dev, > { > struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc; > struct rbd_client_id cid = rbd_get_cid(rbd_dev); > - int buf_size = 4 + 8 + 8 + CEPH_ENCODING_START_BLK_LEN; > - char buf[buf_size]; > + char buf[4 + 4 + 8 + 8 + CEPH_ENCODING_START_BLK_LEN]; > + int buf_size = sizeof(buf); > void *p = buf; > > dout("%s rbd_dev %p notify_op %d\n", __func__, rbd_dev, notify_op); > @@ -3619,8 +3619,8 @@ static void __rbd_acknowledge_notify(struct > rbd_device *rbd_dev, > u64 notify_id, u64 cookie, s32 *result) > { > struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc; > - int buf_size = 4 + CEPH_ENCODING_START_BLK_LEN; > - char buf[buf_size]; > + char buf[4 + CEPH_ENCODING_START_BLK_LEN]; > + int buf_size = sizeof(buf); > int ret; > > if (result) { > -- 2.7.4 >
On Sat, Mar 10, 2018 at 6:14 AM, Kyle Spiers <kyle@spiers.me> wrote: > From 4198ebe2e8058ff676d8e2f993d8806d6ca29c11 Mon Sep 17 00:00:00 2001 > From: Kyle Spiers <kyle@spiers.me> > Date: Fri, 9 Mar 2018 12:34:15 -0800 > Subject: [PATCH] rbd: Remove VLA usage > > As part of the effort to remove VLAs from the kernel[1], this moves > the literal values into the stack array calculation instead of using a > variable for the sizing. The resulting size can be found from > sizeof(buf). > > [1] https://lkml.org/lkml/2018/3/7/621 > > Signed-off-by: Kyle Spiers <kyle@spiers.me> > > --- > drivers/block/rbd.c | 8 ++++---- > 1 file changed, 4 insertions(+), 4 deletions(-) > > diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c > index 8e40da0..0e94e1f 100644 > --- a/drivers/block/rbd.c > +++ b/drivers/block/rbd.c > @@ -3100,8 +3100,8 @@ static int __rbd_notify_op_lock(struct rbd_device > *rbd_dev, > { > struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc; > struct rbd_client_id cid = rbd_get_cid(rbd_dev); > - int buf_size = 4 + 8 + 8 + CEPH_ENCODING_START_BLK_LEN; > - char buf[buf_size]; > + char buf[4 + 4 + 8 + 8 + CEPH_ENCODING_START_BLK_LEN]; > + int buf_size = sizeof(buf); > void *p = buf; > > dout("%s rbd_dev %p notify_op %d\n", __func__, rbd_dev, notify_op); > @@ -3619,8 +3619,8 @@ static void __rbd_acknowledge_notify(struct > rbd_device *rbd_dev, > u64 notify_id, u64 cookie, s32 *result) > { > struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc; > - int buf_size = 4 + CEPH_ENCODING_START_BLK_LEN; > - char buf[buf_size]; > + char buf[4 + CEPH_ENCODING_START_BLK_LEN]; > + int buf_size = sizeof(buf); > int ret; > > if (result) { This patch is mangled -- tabs, etc. See https://www.kernel.org/doc/html/v4.15/process/email-clients.html Thanks, Ilya -- To unsubscribe from this list: send the line "unsubscribe ceph-devel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Sat, 10 Mar 2018, Kees Cook wrote: >> As part of the effort to remove VLAs from the kernel[1], this moves >> the literal values into the stack array calculation instead of using a >> variable for the sizing. The resulting size can be found from >> sizeof(buf). VLAs are also used in a number of places in the Ceph codebase. Unfortunately, g++ enables them in C++ (they aren't part of the standard) by default. They're innocently easy to write and give you no ability to check for errors. Good to see renewed attention drawn to this, and I hope we'll consider removing them from Ceph as well (and/or drawing very close attention to them, where they're truly being useful). -Jesse -- To unsubscribe from this list: send the line "unsubscribe ceph-devel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c index 8e40da0..0e94e1f 100644 --- a/drivers/block/rbd.c +++ b/drivers/block/rbd.c @@ -3100,8 +3100,8 @@ static int __rbd_notify_op_lock(struct rbd_device *rbd_dev, { struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc; struct rbd_client_id cid = rbd_get_cid(rbd_dev); - int buf_size = 4 + 8 + 8 + CEPH_ENCODING_START_BLK_LEN; - char buf[buf_size]; + char buf[4 + 4 + 8 + 8 + CEPH_ENCODING_START_BLK_LEN]; + int buf_size = sizeof(buf); void *p = buf;