Re: [PATCH resend] module/decompress: generate sysfs string at compile time

[Dmitry Torokhov <dmitry.torokhov@gmail.com>]

On Tue, Sep 06, 2022 at 10:03:18AM +0200, David Disseldorp wrote:
> compression_show() before (with noinline):
>    0xffffffff810b5ff0 <+0>:     mov    %rdx,%rdi
>    0xffffffff810b5ff3 <+3>:     mov    $0xffffffff81b55629,%rsi
>    0xffffffff810b5ffa <+10>:    mov    $0xffffffff81b0cde2,%rdx
>    0xffffffff810b6001 <+17>:    call   0xffffffff811b8fd0 <sysfs_emit>
>    0xffffffff810b6006 <+22>:    cltq
>    0xffffffff810b6008 <+24>:    ret
> 
> After:
>    0xffffffff810b5ff0 <+0>:     mov    $0xffffffff81b0cde2,%rsi
>    0xffffffff810b5ff7 <+7>:     mov    %rdx,%rdi
>    0xffffffff810b5ffa <+10>:    call   0xffffffff811b8fd0 <sysfs_emit>
>    0xffffffff810b5fff <+15>:    cltq
>    0xffffffff810b6001 <+17>:    ret
> 
> Signed-off-by: David Disseldorp <ddiss@suse.de>
> ---
>  kernel/module/decompress.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> Resend: Maintainer addresses added.
> 
> Feel free to drop the to-be-expected commit message body if desired.
> 
> diff --git a/kernel/module/decompress.c b/kernel/module/decompress.c
> index 4d0bcb3d9e449..c033572d83f0e 100644
> --- a/kernel/module/decompress.c
> +++ b/kernel/module/decompress.c
> @@ -256,7 +256,7 @@ void module_decompress_cleanup(struct load_info *info)
>  static ssize_t compression_show(struct kobject *kobj,
>  				struct kobj_attribute *attr, char *buf)
>  {
> -	return sysfs_emit(buf, "%s\n", __stringify(MODULE_COMPRESSION));
> +	return sysfs_emit(buf, __stringify(MODULE_COMPRESSION) "\n");

I guess we van trust the kernel source not to put garbage into
MODULE_COMPRESSION macro.

Reviewed-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Thanks.

-- 
Dmitry