On Thu, Feb 28, 2019 at 03:10:44PM +0000, Chris Wilson wrote: > Quoting Peter Zijlstra (2019-02-28 14:54:56) > > drivers/gpu/drm/i915/i915_gem_execbuffer.o: warning: objtool: > > .altinstr_replacement+0x3c: redundant UACCESS disable > > drivers/gpu/drm/i915/i915_gem_execbuffer.o: warning: objtool: > > .altinstr_replacement+0x66: redundant UACCESS disable > > > > AKA. you don't need user_access_end() if user_access_begin() fails. > > Cool, I had no idea if it was required or not. The closest to > instructions on how to use user_access_begin() is in > arch/x86/include/asm/uaccess.h ... which I guess is earlier in this > series!
Ah, I don't think I put the rules in a comment; that would've been useful I suppose ;-) I did teach the rules to objtool though, and that is in the next patch: https://lkml.kernel.org/r/20190228150152.635362...@infradead.org so at least it will yell at you during compile time when you get it wrong. > > Cc: Chris Wilson <ch...@chris-wilson.co.uk> > > Signed-off-by: Peter Zijlstra (Intel) <pet...@infradead.org> > > Reviewed-by: Chris Wilson <ch...@chris-wilson.co.uk> Thanks!
