71 lines
1.3 KiB
C
71 lines
1.3 KiB
C
|
/*
|
||
|
|
* Jump label s390 support
|
||
|
|
*
|
||
|
|
* Copyright IBM Corp. 2011
|
||
|
|
* Author(s): Jan Glauber <jang@linux.vnet.ibm.com>
|
||
|
|
*/
|
||
|
|
#include <linux/module.h>
|
||
|
|
#include <linux/uaccess.h>
|
||
|
|
#include <linux/stop_machine.h>
|
||
|
|
#include <linux/jump_label.h>
|
||
|
|
#include <asm/ipl.h>
|
||
|
|
|
||
|
|
#ifdef HAVE_JUMP_LABEL
|
||
|
|
|
||
|
|
struct insn {
|
||
|
|
u16 opcode;
|
||
|
|
s32 offset;
|
||
|
|
} __packed;
|
||
|
|
|
||
|
|
struct insn_args {
|
||
|
|
struct jump_entry *entry;
|
||
|
|
enum jump_label_type type;
|
||
|
|
};
|
||
|
|
|
||
|
|
static void __jump_label_transform(struct jump_entry *entry,
|
||
|
|
enum jump_label_type type)
|
||
|
|
{
|
||
|
|
struct insn insn;
|
||
|
|
int rc;
|
||
|
|
|
||
|
|
if (type == JUMP_LABEL_ENABLE) {
|
||
|
|
/* brcl 15,offset */
|
||
|
|
insn.opcode = 0xc0f4;
|
||
|
|
insn.offset = (entry->target - entry->code) >> 1;
|
||
|
|
} else {
|
||
|
|
/* brcl 0,0 */
|
||
|
|
insn.opcode = 0xc004;
|
||
|
|
insn.offset = 0;
|
||
|
|
}
|
||
|
|
|
||
|
|
rc = probe_kernel_write((void *)entry->code, &insn, JUMP_LABEL_NOP_SIZE);
|
||
|
|
WARN_ON_ONCE(rc < 0);
|
||
|
|
}
|
||
|
|
|
||
|
|
static int __sm_arch_jump_label_transform(void *data)
|
||
|
|
{
|
||
|
|
struct insn_args *args = data;
|
||
|
|
|
||
|
|
__jump_label_transform(args->entry, args->type);
|
||
|
|
return 0;
|
||
|
|
}
|
||
|
|
|
||
|
|
void arch_jump_label_transform(struct jump_entry *entry,
|
||
|
|
enum jump_label_type type)
|
||
|
|
{
|
||
|
|
struct insn_args args;
|
||
|
|
|
||
|
|
args.entry = entry;
|
||
|
|
args.type = type;
|
||
|
|
|
||
|
|
stop_machine(__sm_arch_jump_label_transform, &args, NULL);
|
||
|
|
}
|
||
|
|
|
||
|
|
void arch_jump_label_transform_static(struct jump_entry *entry,
|
||
|
|
enum jump_label_type type)
|
||
|
|
{
|
||
|
|
__jump_label_transform(entry, type);
|
||
|
|
}
|
||
|
|
|
||
|
|
#endif
|