Re: [PATCH 6/6] vfs: introduce FMODE_NEG_OFFSET for allowingnegative f_pos
From: KAMEZAWA Hiroyuki
Date: Sun Jan 17 2010 - 20:52:45 EST
On Mon, 18 Jan 2010 10:32:49 +0900
OGAWA Hirofumi <hirofumi@xxxxxxxxxxxxxxxxxx> wrote:
> OGAWA Hirofumi <hirofumi@xxxxxxxxxxxxxxxxxx> writes:
> >>> Um... How do lseek() work? It sounds like to violate error code range.
> >> This is for read-write. As far as I know,
> >> - generic_file_llseek,
> >> - default_llseek
> >> - no_llseek
> >> doesn't call this function.
> > It seems to allow to set negative value to ->f_pos, right? So, lseek()
> > returns (uses) it?
> BTW, another concern by negative "pos" value is, the following like code
> pos >> shift_bits
> it will break the above. So, I think it should be checked if not yet.
Where do we check ?
FMODE_NEG_OFFSET is just used by /dev/mem and /proc/<pid>/mem. And I don't
think there are no additonal users. So, I myself don't have has such concerns...
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/