linux/arch/arm/kernel/jump_label.c
Ard Biesheuvel 7e6b9db27d jump_label: make initial NOP patching the special case
Instead of defaulting to patching NOP opcodes at init time, and leaving
it to the architectures to override this if this is not needed, switch
to a model where doing nothing is the default. This is the common case
by far, as only MIPS requires NOP patching at init time. On all other
architectures, the correct encodings are emitted by the compiler and so
no initial patching is needed.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20220615154142.1574619-4-ardb@kernel.org
2022-06-24 09:48:55 +02:00

30 lines
661 B
C

// SPDX-License-Identifier: GPL-2.0
#include <linux/kernel.h>
#include <linux/jump_label.h>
#include <asm/patch.h>
#include <asm/insn.h>
static void __arch_jump_label_transform(struct jump_entry *entry,
enum jump_label_type type,
bool is_static)
{
void *addr = (void *)entry->code;
unsigned int insn;
if (type == JUMP_LABEL_JMP)
insn = arm_gen_branch(entry->code, entry->target);
else
insn = arm_gen_nop();
if (is_static)
__patch_text_early(addr, insn);
else
patch_text(addr, insn);
}
void arch_jump_label_transform(struct jump_entry *entry,
enum jump_label_type type)
{
__arch_jump_label_transform(entry, type, false);
}