On 2/5/19 8:33 AM, Borislav Petkov wrote: > 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 <[email protected]> >> Cc: Thomas Gleixner <[email protected]> >> Cc: Ingo Molnar <[email protected]> >> Cc: Borislav Petkov <[email protected]> >> Cc: "H. Peter Anvin" <[email protected]> >> Cc: Greg Kroah-Hartman <[email protected]> >> Cc: Masami Hiramatsu <[email protected]> >> Cc: "Steven Rostedt (VMware)" <[email protected]> >> Cc: Jiri Kosina <[email protected]> >> Cc: Josh Poimboeuf <[email protected]> >> Cc: "Peter Zijlstra (Intel)" <[email protected]> >> Cc: Chris von Recklinghausen <[email protected]> >> Cc: Jason Baron <[email protected]> >> Cc: Scott Wood <[email protected]> >> Cc: Marcelo Tosatti <[email protected]> >> Cc: Clark Williams <[email protected]> >> Cc: [email protected] >> Cc: [email protected] >> --- >> 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... >
agreed. Thanks! -- Daniel
