Messages in this thread Patch in this message | | | From | Daniel Bristot de Oliveira <> | Subject | [PATCH V3 3/9] x86/jump_label: Move checking code away from __jump_label_transform() | Date | Fri, 21 Dec 2018 11:27:28 +0100 |
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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 <bristot@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: "Steven Rostedt (VMware)" <rostedt@goodmis.org> Cc: Jiri Kosina <jkosina@suse.cz> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: "Peter Zijlstra (Intel)" <peterz@infradead.org> Cc: Chris von Recklinghausen <crecklin@redhat.com> Cc: Jason Baron <jbaron@akamai.com> Cc: Scott Wood <swood@redhat.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Clark Williams <williams@redhat.com> Cc: x86@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 aac0c1f7e354..7894080bd02f 100644 --- a/arch/x86/kernel/jump_label.c +++ b/arch/x86/kernel/jump_label.c @@ -37,16 +37,53 @@ 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) - @@ -56,26 +93,13 @@ 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. * -- 2.17.1
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