> -----Original Message-----
> > Linux 5.7 and later kernels that contain kernel commit <1ad53d9fa3f6>
> > ("slub: improve bit diffusion for freelist ptr obfuscation") changed
> > the calculation formula in the freelist_ptr(), which added a swab()
> > call to mix bits a little more. When kernel is built with the
> > "CONFIG_SLAB_FREELIST_HARDENED=y",the "kmem -s" option fails with the
> > following errors, if there is no such patch.
> >
> > crash> kmem -s
> > CACHE OBJSIZE ALLOCATED TOTAL SLABS SSIZE NAME
> > 82166d00 144 0 0 0 4k fuse_request
> > 82166e00 792 0 0 0 16k fuse_inode
> > 87201e00 528 0 0 0 8k xfs_dqtrx
> > 87201f00 496 0 0 0 8k xfs_dquot
> > kmem: xfs_buf: slab: 37202e6e900 invalid freepointer: b844bab900001d70
> > kmem: xfs_buf: slab: 3720250fd80 invalid freepointer: b8603f9400001370
> > ...
>
> Good catch! And the patch diff looks good to me.
Sorry, I completely misread the code.. Please ignore the comments below.
I will check again next week.
Thanks,
Kazu
>
> But the freelist_ptr() function, which is patched, is called only when
> the error message is NOT printed. So it seems like the patch does not
> stop the message, right?
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