On Thu, Jan 30, 2014 at 09:48:02AM +0100, Petr Tesarik wrote: > The loff_t type may be wider than phys_addr_t (e.g. on 32-bit systems). > Consequently, the file offset may be truncated in the assignment. > Currently, /dev/mem wraps around, which may cause applications to read > or write incorrect regions of memory by accident.
Does that really happen? If so, that's a userspace bug, right? > Let's follow POSIX file semantics here and return 0 when reading from > and -EFBIG when writing to an offset that cannot be represented by a > phys_addr_t. > > Note that the conditional is optimized out by the compiler if loff_t > has the same size as phys_addr_t. > > Signed-off-by: Petr Tesarik <ptesa...@suse.cz> > --- > drivers/char/mem.c | 6 ++++++ > 1 file changed, 6 insertions(+) What is going to break if we apply this patch? :) thanks, greg k-h -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
