On Fri, May 29, 2020 at 09:08:56PM +0100, Al Viro wrote: > On Fri, May 29, 2020 at 12:31:04PM -0700, Linus Torvalds wrote: > > On Fri, May 29, 2020 at 9:50 AM Josh Poimboeuf <jpoimboe@xxxxxxxxxx> wrote: > > > > > > From staring at the asm I think the generated code is correct, it's just > > > that the nested likelys with ftrace profiling cause GCC to converge the > > > error/success paths. But objtool doesn't do register value tracking so > > > it's not smart enough to know that it's safe. > > > > I'm surprised that gcc doesn't end up doing the obvious CSE and then > > branch following and folding it all away in the end, but your patch is > > obviously the right thing to do regardless, so ack on that. > > > > Al - I think this had best go into your uaccess cleanup branch with > > that csum-wrapper update, to avoid any unnecessary conflicts or > > dependencies. > > Sure, just let me verify that other branches don't introduce anything > of that sort... ... they don't. OK, folded, rebuild #for-next, pushed both out...