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authorKees Cook <keescook@chromium.org>2017-02-14 01:25:26 +0100
committerJens Axboe <axboe@fb.com>2017-02-14 16:29:56 +0100
commit853fe1bf7554155376bb3b231112cdff9ff79177 (patch)
tree7d8b38a77574919d078443cecffcae9dd380a692 /Documentation/cdrom
parentelevator: fix loading wrong elevator type for blk-mq devices (diff)
downloadlinux-853fe1bf7554155376bb3b231112cdff9ff79177.tar.xz
linux-853fe1bf7554155376bb3b231112cdff9ff79177.zip
cdrom: Make device operations read-only
Since function tables are a common target for attackers, it's best to keep them in read-only memory. As such, this makes the CDROM device ops tables const. This drops additionally n_minors, since it isn't used meaningfully, and sets the only user of cdrom_dummy_generic_packet explicitly so the variables can all be const. Inspired by similar changes in grsecurity/PaX. Signed-off-by: Kees Cook <keescook@chromium.org> Acked-by: David S. Miller <davem@davemloft.net> Signed-off-by: Jens Axboe <axboe@fb.com>
Diffstat (limited to 'Documentation/cdrom')
-rw-r--r--Documentation/cdrom/cdrom-standard.tex9
1 files changed, 1 insertions, 8 deletions
diff --git a/Documentation/cdrom/cdrom-standard.tex b/Documentation/cdrom/cdrom-standard.tex
index c06233fe52ac..8f85b0e41046 100644
--- a/Documentation/cdrom/cdrom-standard.tex
+++ b/Documentation/cdrom/cdrom-standard.tex
@@ -249,7 +249,6 @@ struct& cdrom_device_ops\ \{ \hidewidth\cr
unsigned\ long);\cr
\noalign{\medskip}
&const\ int& capability;& capability flags \cr
- &int& n_minors;& number of active minor devices \cr
\};\cr
}
$$
@@ -258,13 +257,7 @@ it should add a function pointer to this $struct$. When a particular
function is not implemented, however, this $struct$ should contain a
NULL instead. The $capability$ flags specify the capabilities of the
\cdrom\ hardware and/or low-level \cdrom\ driver when a \cdrom\ drive
-is registered with the \UCD. The value $n_minors$ should be a positive
-value indicating the number of minor devices that are supported by
-the low-level device driver, normally~1. Although these two variables
-are `informative' rather than `operational,' they are included in
-$cdrom_device_ops$ because they describe the capability of the {\em
-driver\/} rather than the {\em drive}. Nomenclature has always been
-difficult in computer programming.
+is registered with the \UCD.
Note that most functions have fewer parameters than their
$blkdev_fops$ counterparts. This is because very little of the