Messages in this thread Patch in this message | | | From | Daniel Bristot de Oliveira <> | Subject | [PATCH V6 2/6] x86/jump_label: Add a __jump_label_set_jump_code() helper | Date | Wed, 12 Jun 2019 11:57:27 +0200 |
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Move the definition of the code to be written from __jump_label_transform() to a specialized function. No functional change.
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 | 41 +++++++++++++++++++++++------------- 1 file changed, 26 insertions(+), 15 deletions(-)
diff --git a/arch/x86/kernel/jump_label.c b/arch/x86/kernel/jump_label.c index e631c358f7f4..d3328062b8cf 100644 --- a/arch/x86/kernel/jump_label.c +++ b/arch/x86/kernel/jump_label.c @@ -35,19 +35,19 @@ static void bug_at(unsigned char *ip, int line) BUG(); } -static void __ref __jump_label_transform(struct jump_entry *entry, - enum jump_label_type type, - int init) +static void __jump_label_set_jump_code(struct jump_entry *entry, + enum jump_label_type type, + union jump_code_union *code, + 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; + const void *expect; int line; - jmp.jump = 0xe9; - jmp.offset = jump_entry_target(entry) - - (jump_entry_code(entry) + JUMP_LABEL_NOP_SIZE); + code->jump = 0xe9; + code->offset = jump_entry_target(entry) - + (jump_entry_code(entry) + JUMP_LABEL_NOP_SIZE); if (type == JUMP_LABEL_JMP) { if (init) { @@ -56,19 +56,30 @@ static void __ref __jump_label_transform(struct jump_entry *entry, expect = ideal_nop; line = __LINE__; } - code = &jmp.code; + if (memcmp((void *)jump_entry_code(entry), expect, JUMP_LABEL_NOP_SIZE)) + bug_at((void *)jump_entry_code(entry), line); + } else { if (init) { expect = default_nop; line = __LINE__; } else { - expect = &jmp.code; line = __LINE__; + expect = code->code; line = __LINE__; } - code = ideal_nop; + if (memcmp((void *)jump_entry_code(entry), expect, JUMP_LABEL_NOP_SIZE)) + bug_at((void *)jump_entry_code(entry), line); + + memcpy(code, ideal_nop, JUMP_LABEL_NOP_SIZE); } +} + +static void __ref __jump_label_transform(struct jump_entry *entry, + enum jump_label_type type, + int init) +{ + union jump_code_union code; - if (memcmp((void *)jump_entry_code(entry), expect, JUMP_LABEL_NOP_SIZE)) - bug_at((void *)jump_entry_code(entry), line); + __jump_label_set_jump_code(entry, type, &code, init); /* * As long as only a single processor is running and the code is still @@ -82,12 +93,12 @@ static void __ref __jump_label_transform(struct jump_entry *entry, * always nop being the 'currently valid' instruction */ if (init || system_state == SYSTEM_BOOTING) { - text_poke_early((void *)jump_entry_code(entry), code, + text_poke_early((void *)jump_entry_code(entry), &code, JUMP_LABEL_NOP_SIZE); return; } - text_poke_bp((void *)jump_entry_code(entry), code, JUMP_LABEL_NOP_SIZE, + text_poke_bp((void *)jump_entry_code(entry), &code, JUMP_LABEL_NOP_SIZE, (void *)jump_entry_code(entry) + JUMP_LABEL_NOP_SIZE); } -- 2.20.1
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