On (20/04/14 14:14), Greg KH wrote: > On Tue, Apr 14, 2020 at 09:06:13PM +0900, Sergey Senozhatsky wrote: > > Hello, > > > > Commit ab6f762f0f53162d41 Linus' HEAD. > > > > printk_deferred() does not make sure that it's safe to write to > > per-CPU data, which causes problems when printk_deferred() is > > invoked "too early", before per-CPU areas are initialized. There > > are multiple bug reports, e.g. > > https://bugzilla.kernel.org/show_bug.cgi?id=206847 > > > > -ss > > So where do you want this commit backported to? Well, printk() is affected in all the kernels where printk_deferred() relies on per-CPU data. Which may translate to "pretty much all current stable kernels?" This patch, however, uses printk_safe() bits, so it won't apply on pre-printk_safe() kernels (not sure if we have such -stable kernels though). -ss
