Commit-ID: ddbefdc167f3d492036e6b0babd11a350c3bd3e3 Gitweb: https://git.kernel.org/tip/ddbefdc167f3d492036e6b0babd11a350c3bd3e3 Author: Daniel Bristot de Oliveira <[email protected]> AuthorDate: Fri, 21 Dec 2018 11:27:28 +0100 Committer: Ingo Molnar <[email protected]> CommitDate: Fri, 19 Apr 2019 19:37:34 +0200
x86/jump_label: Move checking code away from __jump_label_transform() 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: Alexander Shishkin <[email protected]> Cc: Andy Lutomirski <[email protected]> Cc: Arnaldo Carvalho de Melo <[email protected]> Cc: Borislav Petkov <[email protected]> Cc: Brian Gerst <[email protected]> Cc: Chris von Recklinghausen <[email protected]> Cc: Clark Williams <[email protected]> Cc: Denys Vlasenko <[email protected]> Cc: Greg Kroah-Hartman <[email protected]> Cc: H. Peter Anvin <[email protected]> Cc: Jason Baron <[email protected]> Cc: Jiri Kosina <[email protected]> Cc: Jiri Olsa <[email protected]> Cc: Josh Poimboeuf <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Marcelo Tosatti <[email protected]> Cc: Masami Hiramatsu <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Scott Wood <[email protected]> Cc: Steven Rostedt (VMware) <[email protected]> Cc: Thomas Gleixner <[email protected]> Link: http://lkml.kernel.org/r/296d5a75c4aee4a957ee7923127c0604903f9daa.1545228276.git.bris...@redhat.com Signed-off-by: Ingo Molnar <[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); +} + + static void __ref __jump_label_transform(struct jump_entry *entry, enum jump_label_type type, void *(*poker)(void *, const void *, size_t), int init) { union jump_code_union jmp; - const unsigned char default_nop[] = { STATIC_KEY_INIT_NOP }; const unsigned char *ideal_nop = ideal_nops[NOP_ATOMIC5]; - const void *expect, *code; - int line; + const void *code; jmp.jump = 0xe9; jmp.offset = jump_entry_target(entry) - @@ -54,26 +91,13 @@ static void __ref __jump_label_transform(struct jump_entry *entry, poker = text_poke_early; if (type == JUMP_LABEL_JMP) { - if (init) { - expect = default_nop; line = __LINE__; - } else { - expect = ideal_nop; line = __LINE__; - } - + __jump_label_trans_check_enable(entry, type, ideal_nop, init); code = &jmp.code; } else { - if (init) { - expect = default_nop; line = __LINE__; - } else { - expect = &jmp.code; line = __LINE__; - } - + __jump_label_trans_check_disable(entry, type, &jmp, init); code = ideal_nop; } - if (memcmp((void *)jump_entry_code(entry), expect, JUMP_LABEL_NOP_SIZE)) - bug_at((void *)jump_entry_code(entry), line); - /* * Make text_poke_bp() a default fallback poker. *
