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x86/jump_label: Add a __jump_label_set_jump_code() helper

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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>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Chris von Recklinghausen <crecklin@redhat.com>
Cc: Clark Williams <williams@redhat.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jason Baron <jbaron@akamai.com>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Scott Wood <swood@redhat.com>
Cc: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/d2f52a0010ecd399cf9b02a65bcf5836571b9e52.1560325897.git.bristot@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Daniel Bristot de Oliveira 2019-06-12 11:57:27 +02:00 committed by Ingo Molnar
parent e1aacb3f4a
commit 4cc6620b5e
1 changed files with 27 additions and 25 deletions
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40
arch/x86/kernel/jump_label.c
View File

@ -35,41 +35,43 @@ static void bug_at(unsigned char *ip, int line)
BUG();
}
static void __ref __jump_label_transform(struct jump_entry *entry,
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) -
code->jump = 0xe9;
code->offset = jump_entry_target(entry) -
(jump_entry_code(entry) + JUMP_LABEL_NOP_SIZE);
if (type == JUMP_LABEL_JMP) {
if (init) {
expect = default_nop; line = __LINE__;
} else {
} else if (type == JUMP_LABEL_JMP) {
expect = ideal_nop; line = __LINE__;
}
code = &jmp.code;
} else {
if (init) {
expect = default_nop; line = __LINE__;
} else {
expect = &jmp.code; line = __LINE__;
}
code = ideal_nop;
expect = code->code; line = __LINE__;
}
if (memcmp((void *)jump_entry_code(entry), expect, JUMP_LABEL_NOP_SIZE))
bug_at((void *)jump_entry_code(entry), line);
if (type == JUMP_LABEL_NOP)
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;
__jump_label_set_jump_code(entry, type, &code, init);
/*
* As long as only a single processor is running and the code is still
* not marked as RO, text_poke_early() can be used; Checking that
@ -82,12 +84,12 @@ 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);
}