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| author | Jason Baron <jbaron@redhat.com> | 2010-09-17 11:09:22 -0400 |
|---|---|---|
| committer | Steven Rostedt <rostedt@goodmis.org> | 2010-09-22 16:33:03 -0400 |
| commit | d9f5ab7b1c0a520867af389bab5d5fcdbd0e407e (patch) | |
| tree | 23c9b85999b4340ec03ba0cef075b8ad73c4c994 /arch/x86/kernel/jump_label.c | |
| parent | 52159d98be6f26c48f5e02c7ab3c9848a85979b5 (diff) | |
| download | linux-d9f5ab7b1c0a520867af389bab5d5fcdbd0e407e.tar.bz2 | |
jump label: x86 support
add x86 support for jump label. I'm keeping this patch separate so its clear
to arch maintainers what was required for x86 support this new feature.
Hopefully, it wouldn't be too painful for other archs.
Signed-off-by: Jason Baron <jbaron@redhat.com>
LKML-Reference: <f838f49f40fbea0254036194be66dc48b598dcea.1284733808.git.jbaron@redhat.com>
[ cleaned up some formatting ]
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Diffstat (limited to 'arch/x86/kernel/jump_label.c')
| -rw-r--r-- | arch/x86/kernel/jump_label.c | 50 |
1 files changed, 50 insertions, 0 deletions
diff --git a/arch/x86/kernel/jump_label.c b/arch/x86/kernel/jump_label.c new file mode 100644 index 000000000000..961b6b30ba90 --- /dev/null +++ b/arch/x86/kernel/jump_label.c @@ -0,0 +1,50 @@ +/* + * 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_nop5, 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_nop5, JUMP_LABEL_NOP_SIZE); +} + +#endif |