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Commit 61f42183 authored by Jeremy Fitzhardinge's avatar Jeremy Fitzhardinge
Browse files

s390/jump-label: add arch_jump_label_transform_static() 



This allows jump-label entries to be cheaply updated on code which is
not yet live.

Signed-off-by: default avatarJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Acked-by: default avatarJason Baron <jbaron@redhat.com>
Acked-by: default avatarPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Jan Glauber <jang@linux.vnet.ibm.com>
parent 20284aa7

arch/s390/kernel/jump_label.c

+31 −20
Original line number Diff line number Diff line
@@ -18,26 +18,15 @@ struct insn { 
} __packed;



struct insn_args {

	unsigned long *target;

	struct insn *insn;

	ssize_t size;

	struct jump_entry *entry;

	enum jump_label_type type;

};



static int __arch_jump_label_transform(void *data)

{

	struct insn_args *args = data;

	int rc;



	rc = probe_kernel_write(args->target, args->insn, args->size);

	WARN_ON_ONCE(rc < 0);

	return 0;

}



void arch_jump_label_transform(struct jump_entry *entry,

static void __jump_label_transform(struct jump_entry *entry,

				   enum jump_label_type type)

{

	struct insn_args args;

	struct insn insn;

	int rc;



	if (type == JUMP_LABEL_ENABLE) {

		/* brcl 15,offset */
@@ -49,11 +38,33 @@ void arch_jump_label_transform(struct jump_entry *entry, 
		insn.offset = 0;

	}



	args.target = (void *) entry->code;

	args.insn = &insn;

	args.size = JUMP_LABEL_NOP_SIZE;

	rc = probe_kernel_write((void *)entry->code, &insn, JUMP_LABEL_NOP_SIZE);

	WARN_ON_ONCE(rc < 0);

}



	stop_machine(__arch_jump_label_transform, &args, NULL);

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