On Mon, Dec 8, 2014 at 5:50 PM, Grant Likely <grant.likely@xxxxxxxxxx> wrote: > On Sat, 6 Dec 2014 14:55:33 +0100 > , Pavel Machek <pavel@xxxxxxx> > wrote: >> Hi! >> >> > > I am accustomed to doing 'echo -n' for most of sysfs anyway. Once in a >> > > while I am a bonehead and forget the '-n' and spend a few minutes >> > > wondering why this thing that worked last week suddenly rejects all >> > > commands. I'm just trying to make my user interface a bit user-friendly. >> > > >> > > I will take out the '\n' stripping and update the documentation. I didn't >> > > realize this would be controversial. >> > >> > Don't. You're doing the right thing by scrubbing your input. Requiring >> > 'echo -n' is just stupid when it is so easy to make work easily. >> >> 'foo\nbar\n' is unusual but valid filename in linux. It is bad idea to >> echo filenames into files in the first place... and arbitrarily >> disallowing certain filenames is not helping. > > Meh. Just because it is a valid linux filename doesn't mean this > interface is forced to accept it. There should be tighter rules about > how the filename can be constructed. Allowing any arbitrary path for any > arbitrary valid linux filename makes for a large attack surface. > > I would like to know, what is the purpose of the interface? Why is it > important to provide the firmware filename in this manor? Are there > going to be a lot of different FPGA bitstreams that may need to be > loaded? How does userspace choose between them, and is there a better > way to do the selection without passing the firmware filename through > the kernel? Is this merely intended to get udev to behave in a certain > way? If so, then maybe there is a better way to go about it. > > We could for example use a UDEV 'PROGRAM=' rule to execute a userspace > app and have that program figure out which firmware file to provide to > the kernel. Correction, a 'RUN+=' rule is actually what I mean here. The PROGRAM= tag is for executing a program to determine if a device matches. g. -- To unsubscribe from this list: send the line "unsubscribe linux-doc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
