Commit 312b1485 authored by Sam Ravnborg's avatar Sam Ravnborg
Browse files

Introduce new section reference annotations tags: __ref, __refdata, __refconst 



Today we have the following annotations for functions/data
referencing __init/__exit functions / data:

__init_refok     => for init functions
__initdata_refok => for init data
__exit_refok     => for exit functions

There is really no difference between the __init and __exit
versions and simplify it and to introduce a shorter annotation
the following new annotations are introduced:

__ref      => for functions (code) that
              references __*init / __*exit
__refdata  => for variables
__refconst => for const variables

Whit this annotation is it more obvious what the annotation
is for and there is no longer the arbitary division
between __init and __exit code.

The mechanishm is the same as before - a special section
is created which is made part of the usual sections
in the linker script.

We will start to see annotations like this:

-static struct pci_serial_quirk pci_serial_quirks[] = {
+static const struct pci_serial_quirk pci_serial_quirks[] __refconst = {
-----------------
-static struct notifier_block __cpuinitdata cpuid_class_cpu_notifier =
+static struct notifier_block cpuid_class_cpu_notifier __refdata =
----------------
-static int threshold_cpu_callback(struct notifier_block *nfb,
+static int __ref threshold_cpu_callback(struct notifier_block *nfb,

[The above is just random samples].

Note: No modifications were needed in modpost
to support the new sections due to the newly introduced
blacklisting.

Signed-off-by: default avatarSam Ravnborg <sam@ravnborg.org>
parent e241a630

include/asm-generic/vmlinux.lds.h

+3 −0
Original line number Diff line number Diff line
@@ -42,6 +42,7 @@ 
#define DATA_DATA							\

	*(.data)							\

	*(.data.init.refok)						\

	*(.ref.data)							\

	DEV_KEEP(init.data)						\

	DEV_KEEP(exit.data)						\

	CPU_KEEP(init.data)						\
@@ -169,6 +170,7 @@ 
									\

	/* __*init sections */						\

	__init_rodata : AT(ADDR(__init_rodata) - LOAD_OFFSET) {		\

		*(.ref.rodata)						\

		DEV_KEEP(init.rodata)					\

		DEV_KEEP(exit.rodata)					\

		CPU_KEEP(init.rodata)					\
@@ -202,6 +204,7 @@ 
#define TEXT_TEXT							\

		ALIGN_FUNCTION();					\

		*(.text)						\

		*(.ref.text)						\

		*(.text.init.refok)					\

		*(.exit.text.refok)					\

	DEV_KEEP(init.text)						\

include/linux/init.h

+27 −7
Original line number Diff line number Diff line
@@ -52,12 +52,26 @@ 
 * 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 *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. */

#define __init_refok     noinline __section(.text.init.refok)

#define __initdata_refok          __section(.data.init.refok)

#define __exit_refok     noinline __section(.exit.text.refok)

#define __ref            __section(.ref.text) noinline

#define __refdata        __section(.ref.data)

#define __refconst       __section(.ref.rodata)



/* backward compatibility note

 *  A few places hardcode the old section names:

 *  .text.init.refok

 *  .data.init.refok

 *  .exit.text.refok

 *  They should be converted to use the defines from this file

 */



/* compatibility defines */

#define __init_refok     __ref

#define __initdata_refok __refdata

#define __exit_refok     __ref





#ifdef MODULE

#define __exitused
@@ -93,11 +107,9 @@ 


/* For assembly routines */

#define __INIT		.section	".init.text","ax"

#define __INIT_REFOK	.section	".text.init.refok","ax"

#define __FINIT		.previous



#define __INITDATA	.section	".init.data","aw"

#define __INITDATA_REFOK .section	".data.init.refok","aw"



#define __DEVINIT        .section	".devinit.text", "ax"

#define __DEVINITDATA    .section	".devinit.data", "aw"
@@ -108,6 +120,14 @@ 
#define __MEMINIT        .section	".meminit.text", "ax"

#define __MEMINITDATA    .section	".meminit.data", "aw"



/* silence warnings when references are OK */

#define __REF            .section       ".ref.text", "ax"

#define __REFDATA        .section       ".ref.data", "aw"

#define __REFCONST       .section       ".ref.rodata", "aw"

/* backward compatibility */

#define __INIT_REFOK     .section	__REF

#define __INITDATA_REFOK .section	__REFDATA



#ifndef __ASSEMBLY__

/*

 * Used for initialization calls..

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