On Mon, 2025-01-20 at 06:28 +0100, Florian Weimer wrote: > * Xi Ruoyao: > > > On Wed, 2024-12-11 at 11:23 +0100, Christian Brauner wrote: > > > On Tue, Dec 10, 2024 at 07:14:07PM +0100, Florian Weimer wrote: > > > > * Aleksa Sarai: > > > > > > > > > sched_getattr(2) doesn't care about trailing non-zero bytes in the > > > > > (ksize > usize) case, so just use copy_struct_to_user() without checking > > > > > ignored_trailing. > > > > > > > > I think this is what causes glibc's misc/tst-sched_setattr test to fail > > > > on recent kernels. The previous non-modifying behavior was documented > > > > in the manual page: > > > > > > > > If the caller-provided attr buffer is larger than the kernel's > > > > sched_attr structure, the additional bytes in the user-space > > > > structure are not touched. > > > > > > > > I can just drop this part of the test if the kernel deems both behaviors > > > > valid. > > > > > I think in general both behaviors are valid but I would consider zeroing > > > the unknown parts of the provided buffer to be the safer option. And all > > > newer extensible struct system calls do that. > > > > Florian, > > > > So should we drop the test before Glibc-2.41 release? I'm seeing the > > failure during my machine test. > I was waiting for a verdict from the kernel developers. I didn't expect > such a change to happen given the alleged UAPI policy. But 6.13 is already released without reverting the behavior change now... So is this the "final" verdict? -- Xi Ruoyao <xry111@xxxxxxxxxxx> School of Aerospace Science and Technology, Xidian University
