Em Mon, 26 Mar 2018 21:47:33 +0300 Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx> escreveu: > Hi Mauro, > > On Monday, 26 March 2018 13:08:16 EEST Mauro Carvalho Chehab wrote: > > Em Fri, 23 Mar 2018 23:53:56 +0200 Sakari Ailus escreveu: > > > On Fri, Mar 23, 2018 at 07:56:54AM -0400, Mauro Carvalho Chehab wrote: > > >> While the code there is right, it produces three false positives: > > >> drivers/media/v4l2-core/v4l2-ioctl.c:2868 video_usercopy() error: > > >> copy_from_user() 'parg' too small (128 vs 16383) > > >> drivers/media/v4l2-core/v4l2-ioctl.c:2868 video_usercopy() error: > > >> copy_from_user() 'parg' too small (128 vs 16383) > > >> drivers/media/v4l2-core/v4l2-ioctl.c:2876 video_usercopy() error: > > >> memset() 'parg' too small (128 vs 16383)> > > > >> Store the ioctl size on a cache var, in order to suppress those. > > > > > > I have to say I'm not a big fan of changing perfectly fine code in order > > > to please static analysers. > > > > Well, there's a side effect of this patch: it allows gcc to better > > optimize the text size, with is good: > > > > text data bss dec hex filename > > 34538 2320 0 36858 > > 8ffa old/drivers/media/v4l2-core/v4l2-ioctl.o 34490 2320 0 > > 36810 8fca new/drivers/media/v4l2-core/v4l2-ioctl.o > > > What's this, smatch? I wonder if it could be fixed > > > instead of changing the code. That'd be presumably a lot more work though. > > > > Yes, the warnings came from smatch. No idea how easy/hard would be to > > change it. > > > > > On naming --- "size" is rather more generic, but it's not a long function > > > either. I'd be a bit more specific, e.g. ioc_size or arg_size. > > > > Agreed. > > > > I'll add the enclosed patch changing it to ioc_size. > > > > > > Thanks, > > Mauro > > > > [PATCH] media: v4l2-ioctl: rename a temp var that stores _IOC_SIZE(cmd) > > > > Instead of just calling it as "size", let's name it as "ioc_size", > > as it reflects better its contents. > > > > As this is constant along the function, also mark it as const. > > > > Signed-off-by: Mauro Carvalho Chehab <mchehab@xxxxxxxxxxxxxxxx> > > I would have expected a v2 of the original patch, but it seems you pushed it > to the public master branch before giving anyone a change to review it > (Sakari's review came 10h after the past was posted). > > Patches need to be reviewed before being applied, and that applies to all > patches, regarding of the author. Please refrain from merging future patches > before they get reviewed. It shouldn't have pushed. It happened due to some script errors, when I was handling a request from Hans to push upstream some fixes for -rc7, as mentioned on IRC: https://linuxtv.org/irc/irclogger_log/v4l?date=2018-03-23,Fri As I said there: "If someone finds an issue on the warning fixes, I can revert or apply a fixup I really hate when things like that happens :-(" Thanks, Mauro
