(2015/02/13 14:40), Wang Nan wrote:
> When registering early kprobes, SMP should has not been enabled, so
> doesn't require synchronization in text_poke_bp(). Simply memcpy is
> enough.
BTW, we've already have text_poke_early for this purpose.
Thank you,
>
> Signed-off-by: Wang Nan <wangn...@huawei.com>
> ---
> arch/x86/kernel/kprobes/opt.c | 12 ++++++++++--
> 1 file changed, 10 insertions(+), 2 deletions(-)
>
> diff --git a/arch/x86/kernel/kprobes/opt.c b/arch/x86/kernel/kprobes/opt.c
> index 0dd8d08..21847ab 100644
> --- a/arch/x86/kernel/kprobes/opt.c
> +++ b/arch/x86/kernel/kprobes/opt.c
> @@ -36,6 +36,7 @@
> #include <asm/alternative.h>
> #include <asm/insn.h>
> #include <asm/debugreg.h>
> +#include <asm/tlbflush.h>
>
> #include "common.h"
>
> @@ -397,8 +398,15 @@ void arch_optimize_kprobes(struct list_head *oplist)
> insn_buf[0] = RELATIVEJUMP_OPCODE;
> *(s32 *)(&insn_buf[1]) = rel;
>
> - text_poke_bp(op->kp.addr, insn_buf, RELATIVEJUMP_SIZE,
> - op->optinsn.insn);
> + if (unlikely(kprobes_is_early())) {
> + BUG_ON(!(op->kp.flags & KPROBE_FLAG_EARLY));
> + memcpy(op->kp.addr, insn_buf, RELATIVEJUMP_SIZE);
> + local_flush_tlb();
> + sync_core();
> + } else {
> + text_poke_bp(op->kp.addr, insn_buf, RELATIVEJUMP_SIZE,
> + op->optinsn.insn);
> + }
>
> list_del_init(&op->list);
> }
>
--
Masami HIRAMATSU
Software Platform Research Dept. Linux Technology Research Center
Hitachi, Ltd., Yokohama Research Laboratory
E-mail: masami.hiramatsu...@hitachi.com
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