On Mon, Feb 27, 2012 at 04:26:31PM -0800, Andrew Morton wrote: > On Tue, 28 Feb 2012 09:19:28 +0900 > Simon Horman <horms at verge.net.au> wrote: > > > > > --- a/kernel/kexec.c > > > > +++ b/kernel/kexec.c > > > > @@ -1462,7 +1462,9 @@ static int __init crash_save_vmcoreinfo_init(void) > > > > > > > > VMCOREINFO_SYMBOL(init_uts_ns); > > > > VMCOREINFO_SYMBOL(node_online_map); > > > > +#ifdef CONFIG_MMU > > > > VMCOREINFO_SYMBOL(swapper_pg_dir); > > > > +#endif > > > > VMCOREINFO_SYMBOL(_stext); > > > > VMCOREINFO_SYMBOL(vmlist); > > > > > > Well, what might be the effects of this patch? nommu crashfiles will > > > no longer have the swapper_pg_dir string? What are the chances that > > > someone's (badly written!) downstream tool will crash and burn if this > > > is absent? > > > > My understanding is that up until this patch creating a dump > > for nonmmu platform wouldn't work. > > Surprised. From reading the code I expect it would have emitted > > SYMBOL(swapper_pg_dir)=0 Hi Andrew, My understanding from discussion with Will earlier in this thread is that if CONFIG_MMU is not defined then swapper_pg_dir is NULL and the current code doesn't compile. <quote> The only case where it's interesting is when you have CONFIG_MMU enabled - otherwise it's always NULL. If it's #defined as NULL, the current code will fail at build time so simply omitting it from the dump seems like the best bet to me (the alternative being to add a NULL entry explicitly, but I don't see what the gains us). </quote>
