On Mon, Feb 04, 2019 at 08:58:56PM +0100, Daniel Bristot de Oliveira wrote:
> Move the check of the current code, before updating an entry, to specialized
> functions. No changes in the method, only code relocation.
>
> Signed-off-by: Daniel Bristot de Oliveira <bris...@redhat.com>
> Cc: Thomas Gleixner <t...@linutronix.de>
> Cc: Ingo Molnar <mi...@redhat.com>
> Cc: Borislav Petkov <b...@alien8.de>
> Cc: "H. Peter Anvin" <h...@zytor.com>
> Cc: Greg Kroah-Hartman <gre...@linuxfoundation.org>
> Cc: Masami Hiramatsu <mhira...@kernel.org>
> Cc: "Steven Rostedt (VMware)" <rost...@goodmis.org>
> Cc: Jiri Kosina <jkos...@suse.cz>
> Cc: Josh Poimboeuf <jpoim...@redhat.com>
> Cc: "Peter Zijlstra (Intel)" <pet...@infradead.org>
> Cc: Chris von Recklinghausen <creck...@redhat.com>
> Cc: Jason Baron <jba...@akamai.com>
> Cc: Scott Wood <sw...@redhat.com>
> Cc: Marcelo Tosatti <mtosa...@redhat.com>
> Cc: Clark Williams <willi...@redhat.com>
> Cc: x...@kernel.org
> Cc: linux-kernel@vger.kernel.org
> ---
> arch/x86/kernel/jump_label.c | 60 +++++++++++++++++++++++++-----------
> 1 file changed, 42 insertions(+), 18 deletions(-)
>
> diff --git a/arch/x86/kernel/jump_label.c b/arch/x86/kernel/jump_label.c
> index f99bd26bd3f1..e443c43478eb 100644
> --- a/arch/x86/kernel/jump_label.c
> +++ b/arch/x86/kernel/jump_label.c
> @@ -35,16 +35,53 @@ static void bug_at(unsigned char *ip, int line)
> BUG();
> }
>
> +static inline void __jump_label_trans_check_enable(struct jump_entry *entry,
> + enum jump_label_type type,
> + const unsigned char
> *ideal_nop,
> + int init)
> +{
> + const unsigned char default_nop[] = { STATIC_KEY_INIT_NOP };
> + const void *expect;
> + int line;
> +
> + if (init) {
> + expect = default_nop; line = __LINE__;
> + } else {
> + expect = ideal_nop; line = __LINE__;
> + }
> +
> + if (memcmp((void *)jump_entry_code(entry), expect, JUMP_LABEL_NOP_SIZE))
> + bug_at((void *)jump_entry_code(entry), line);
> +}
> +
> +static inline void __jump_label_trans_check_disable(struct jump_entry *entry,
> + enum jump_label_type type,
> + union jump_code_union *jmp,
> + int init)
> +{
> + const unsigned char default_nop[] = { STATIC_KEY_INIT_NOP };
> + const void *expect;
> + int line;
> +
> + if (init) {
> + expect = default_nop; line = __LINE__;
> + } else {
> + expect = jmp->code; line = __LINE__;
> + }
> +
> + if (memcmp((void *)jump_entry_code(entry), expect, JUMP_LABEL_NOP_SIZE))
> + bug_at((void *)jump_entry_code(entry), line);
> +}
Why the carve out?
The next patch is adding __jump_label_set_jump_code() which calls them
so you could just as well keep the functionality all in that function without
having too many helpers which are called only once...
--
Regards/Gruss,
Boris.
Good mailing practices for 400: avoid top-posting and trim the reply.
