mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-12-15 00:16:43 +07:00
dc326fca2b
Clean up and unify the NOP selection infrastructure: - Make the atomic 5-byte NOP a part of the selection system. - Pick NOPs once during early boot and then be done with it. Signed-off-by: H. Peter Anvin <hpa@linux.intel.com> Cc: Tejun Heo <tj@kernel.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Jason Baron <jbaron@redhat.com> Link: http://lkml.kernel.org/r/1303166160-10315-3-git-send-email-hpa@linux.intel.com
52 lines
1.1 KiB
C
52 lines
1.1 KiB
C
/*
|
|
* jump label x86 support
|
|
*
|
|
* Copyright (C) 2009 Jason Baron <jbaron@redhat.com>
|
|
*
|
|
*/
|
|
#include <linux/jump_label.h>
|
|
#include <linux/memory.h>
|
|
#include <linux/uaccess.h>
|
|
#include <linux/module.h>
|
|
#include <linux/list.h>
|
|
#include <linux/jhash.h>
|
|
#include <linux/cpu.h>
|
|
#include <asm/kprobes.h>
|
|
#include <asm/alternative.h>
|
|
|
|
#ifdef HAVE_JUMP_LABEL
|
|
|
|
union jump_code_union {
|
|
char code[JUMP_LABEL_NOP_SIZE];
|
|
struct {
|
|
char jump;
|
|
int offset;
|
|
} __attribute__((packed));
|
|
};
|
|
|
|
void arch_jump_label_transform(struct jump_entry *entry,
|
|
enum jump_label_type type)
|
|
{
|
|
union jump_code_union code;
|
|
|
|
if (type == JUMP_LABEL_ENABLE) {
|
|
code.jump = 0xe9;
|
|
code.offset = entry->target -
|
|
(entry->code + JUMP_LABEL_NOP_SIZE);
|
|
} else
|
|
memcpy(&code, ideal_nops[NOP_ATOMIC5], JUMP_LABEL_NOP_SIZE);
|
|
get_online_cpus();
|
|
mutex_lock(&text_mutex);
|
|
text_poke_smp((void *)entry->code, &code, JUMP_LABEL_NOP_SIZE);
|
|
mutex_unlock(&text_mutex);
|
|
put_online_cpus();
|
|
}
|
|
|
|
void arch_jump_label_text_poke_early(jump_label_t addr)
|
|
{
|
|
text_poke_early((void *)addr, ideal_nops[NOP_ATOMIC5],
|
|
JUMP_LABEL_NOP_SIZE);
|
|
}
|
|
|
|
#endif
|