diff options
Diffstat (limited to 'arch/x86/kernel/jump_label.c')
-rw-r--r-- | arch/x86/kernel/jump_label.c | 59 |
1 files changed, 59 insertions, 0 deletions
diff --git a/arch/x86/kernel/jump_label.c b/arch/x86/kernel/jump_label.c new file mode 100644 index 00000000..2889b3d4 --- /dev/null +++ b/arch/x86/kernel/jump_label.c @@ -0,0 +1,59 @@ +/* + * 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)); +}; + +static void __jump_label_transform(struct jump_entry *entry, + enum jump_label_type type, + void *(*poker)(void *, const void *, size_t)) +{ + 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); + + (*poker)((void *)entry->code, &code, JUMP_LABEL_NOP_SIZE); +} + +void arch_jump_label_transform(struct jump_entry *entry, + enum jump_label_type type) +{ + get_online_cpus(); + mutex_lock(&text_mutex); + __jump_label_transform(entry, type, text_poke_smp); + mutex_unlock(&text_mutex); + put_online_cpus(); +} + +__init_or_module void arch_jump_label_transform_static(struct jump_entry *entry, + enum jump_label_type type) +{ + __jump_label_transform(entry, type, text_poke_early); +} + +#endif |