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authorMichal Nazarewicz <m.nazarewicz@samsung.com>2010-08-12 19:43:56 +0400
committerGreg Kroah-Hartman <gregkh@suse.de>2010-10-22 21:21:26 +0400
commit5ea081785dde6041eb2f4acc2369abbb9099a981 (patch)
treed947b2b297f687a9052207244f730df73994beea /include/linux/init.h
parentc9bfff9c98671ad50e4abbfe1ab606a9957f7539 (diff)
downloadlinux-5ea081785dde6041eb2f4acc2369abbb9099a981.tar.xz
init.h: add some more documentation to __ref* tags
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 <m.nazarewicz@samsung.com> Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Acked-by: Sam Ravnborg <sam@ravnborg.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'include/linux/init.h')
-rw-r--r--include/linux/init.h13
1 files changed, 10 insertions, 3 deletions
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)