>
> --=-=-=
>
> Hi Linus and Kanoj,
>
> The following patch makes mmap MAP_ANON|MAP_SHARED possible.
>
> I had to change the i_dev input for /dev/zero shared mappings but I
> think this is at least not worse than before. The inode does
> definitely not belong to the block device /dev/zero is located on.
>
> Greetings
> Christoph
>
The patch looks good. I would just ask you to illustrate with a small
program that mmaps /dev/zero MAP_SHARED and then does a "cat /proc/pid/maps"
on itself. I think instead of reporting the root device numbers for the
/dev/zero mapping, it will report the shmfs device numbers.
Ie,
instead of
08048000-0804e000 r-xp 00000000 08:01 XXXXXXXX /dev/zero
it will say something like
08048000-0804e000 r-xp 00000000 AB:CD XXXXXXXX /dev/zero
I can't think of a problem this would cause, unless you claim an
user might be confused to see /dev/zero, but a different device
for the file.
Btw, even for MAP_ANON|MAP_SHARED, the filename reported via
"cat /proc/pid/maps" will show up as /dev/zero (I _think_), did
you want to change that?
Kanoj
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