Messages in this thread | | | Subject | Re: [PATCH 2/1] init/Kconfig: Split expert menu into a separate file, init/Kconfig.expert | From | Paul Bolle <> | Date | Thu, 28 May 2015 10:13:11 +0200 |
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[Yes, this patch is superseded by your series starting at https://lkml.org/lkml/2015/5/14/447 . But I wanted to jot this down somewhere.]
On Tue, 2015-05-12 at 00:15 +0200, Paul Bolle wrote: > On Mon, 2015-05-11 at 15:04 -0700, Josh Triplett wrote: > > On Mon, May 11, 2015 at 11:50:21PM +0200, Paul Bolle wrote: > > > On Mon, 2015-05-11 at 13:23 -0700, Josh Triplett wrote: > > > > +config KALLSYMS_ALL > > > > + bool "Include all symbols in kallsyms" > > > > > > (For some reason this entry doesn't have if EXPERT but it seems to > > > behave as expected. Odd.) > > > > Because it depends on KALLSYMS. Magic! > > Welcome to the land of Kconfig!
It's even more subtle (at least currently, ie before this patch is applied).
KALLSYMS_ALL's prompt doesn't depend on EXPERT. KALLSYMS's prompt does. For some reason, perhaps because KALLSYMS_ALL depends on KALLSYMS, this makes both entries visible under EXPERT's menu even if EXPERT is _not_ set.
But, in contrast to BPF_SYSCALL, this doesn't influence the following symbols that do have a prompt that depends on EXPERT.
Adding "if EXPERT" to the prompt of KALLSYMS_ALL does hide that symbol _and_ KALLSYMS (when EXPERT is not set, of course).
(This may be documented, or clearly commented in the code. I didn't check.)
> > > > + depends on DEBUG_KERNEL && KALLSYMS > > > > + help > > > > + Normally kallsyms only contains the symbols of functions for nicer > > > > + OOPS messages and backtraces (i.e., symbols from the text and inittext > > > > + sections). This is sufficient for most cases. And only in very rare > > > > + cases (e.g., when a debugger is used) all symbols are required (e.g., > > > > + names of variables from the data sections, etc). > > > > + > > > > + This option makes sure that all symbols are loaded into the kernel > > > > + image (i.e., symbols from all sections) in cost of increased kernel > > > > + size (depending on the kernel configuration, it may be 300KiB or > > > > + something like this). > > > > + > > > > + Say N unless you really need all symbols.
Thanks,
Paul Bolle
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