[PATCH] livepatch: Let compiler put module initialized function to section ".init.text"

[PATCH] livepatch: Let compiler put module initialized function to section ".init.text"

[Minfei Huang]

From: Minfei Huang <mnfhuang@gmail.com>

Usually we prefer to let compiler put the module initialized function to
section ".init.text". Thus this text in memory will be freed in future.

Once we add the "__init" preceding function name, we can use following
command to find it in specfied section.

  $ objdump -t -j .init.text built-in.o

  built-in.o:     file format elf64-x86-64

  SYMBOL TABLE:
  0000000000000000 l    d  .init.text	0000000000000000 .init.text
  0000000000000000 l     F .init.text	000000000000004e klp_init

Signed-off-by: Minfei Huang <mnfhuang@gmail.com>
---
 kernel/livepatch/core.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/livepatch/core.c b/kernel/livepatch/core.c
index 284e269..86e40b9 100644
--- a/kernel/livepatch/core.c
+++ b/kernel/livepatch/core.c
@@ -973,7 +973,7 @@ static struct notifier_block klp_module_nb = {
 	.priority = INT_MIN+1, /* called late but before ftrace notifier */
 };
 
-static int klp_init(void)
+static int __init klp_init(void)
 {
 	int ret;
 
-- 
2.2.2

Re: [PATCH] livepatch: Let compiler put module initialized function to section ".init.text"

[Josh Poimboeuf]

On Fri, May 22, 2015 at 02:10:32PM +0800, Minfei Huang wrote:
> From: Minfei Huang <mnfhuang@gmail.com>
> 
> Usually we prefer to let compiler put the module initialized function to
> section ".init.text". Thus this text in memory will be freed in future.
> 
> Once we add the "__init" preceding function name, we can use following
> command to find it in specfied section.
> 
>   $ objdump -t -j .init.text built-in.o
> 
>   built-in.o:     file format elf64-x86-64
> 
>   SYMBOL TABLE:
>   0000000000000000 l    d  .init.text	0000000000000000 .init.text
>   0000000000000000 l     F .init.text	000000000000004e klp_init
> 
> Signed-off-by: Minfei Huang <mnfhuang@gmail.com>

The patch looks good but can you make the subject more concise?  Maybe
something like:

  livepatch: annotate klp_init() with __init

Thanks.

-- 
Josh

Re: [PATCH] livepatch: Let compiler put module initialized function to section ".init.text"

[Minfei Huang]

On 05/22/15 at 08:25P, Josh Poimboeuf wrote:
> On Fri, May 22, 2015 at 02:10:32PM +0800, Minfei Huang wrote:
> > From: Minfei Huang <mnfhuang@gmail.com>
> > 
> > Usually we prefer to let compiler put the module initialized function to
> > section ".init.text". Thus this text in memory will be freed in future.
> > 
> > Once we add the "__init" preceding function name, we can use following
> > command to find it in specfied section.
> > 
> >   $ objdump -t -j .init.text built-in.o
> > 
> >   built-in.o:     file format elf64-x86-64
> > 
> >   SYMBOL TABLE:
> >   0000000000000000 l    d  .init.text	0000000000000000 .init.text
> >   0000000000000000 l     F .init.text	000000000000004e klp_init
> > 
> > Signed-off-by: Minfei Huang <mnfhuang@gmail.com>
> 
> The patch looks good but can you make the subject more concise?  Maybe
> something like:
> 
>   livepatch: annotate klp_init() with __init

Sure. Will modify the subject.

Thanks
Minfei

> 
> Thanks.
> 
> -- 
> Josh