From 5ea081785dde6041eb2f4acc2369abbb9099a981 Mon Sep 17 00:00:00 2001 From: Michal Nazarewicz Date: Thu, 12 Aug 2010 17:43:56 +0200 Subject: init.h: add some more documentation to __ref* tags MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The __ref* tags may have been confusing for new kernel developers (I was confused by them for sure) so adding a few more sentences to comment to clear things up for people who see those for the first time. Signed-off-by: Michal Nazarewicz Acked-by: Uwe Kleine-König Acked-by: Sam Ravnborg Signed-off-by: Greg Kroah-Hartman --- include/linux/init.h | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-) (limited to 'include/linux/init.h') diff --git a/include/linux/init.h b/include/linux/init.h index de994304e0bb..577671c55153 100644 --- a/include/linux/init.h +++ b/include/linux/init.h @@ -46,16 +46,23 @@ #define __exitdata __section(.exit.data) #define __exit_call __used __section(.exitcall.exit) -/* modpost check for section mismatches during the kernel build. +/* + * modpost check for section mismatches during the kernel build. * A section mismatch happens when there are references from a * code or data section to an init section (both code or data). * The init sections are (for most archs) discarded by the kernel * when early init has completed so all such references are potential bugs. * For exit sections the same issue exists. + * * The following markers are used for the cases where the reference to * the *init / *exit section (code or data) is valid and will teach - * modpost not to issue a warning. - * The markers follow same syntax rules as __init / __initdata. */ + * modpost not to issue a warning. Intended semantics is that a code or + * data tagged __ref* can reference code or data from init section without + * producing a warning (of course, no warning does not mean code is + * correct, so optimally document why the __ref is needed and why it's OK). + * + * The markers follow same syntax rules as __init / __initdata. + */ #define __ref __section(.ref.text) noinline #define __refdata __section(.ref.data) #define __refconst __section(.ref.rodata) -- cgit v1.2.3-59-g8ed1b