From mboxrd@z Thu Jan 1 00:00:00 1970 From: wangnan0@huawei.com (Wang Nan) Date: Thu, 12 Feb 2015 20:20:40 +0800 Subject: [RFC PATCH v2 15/26] early kprobes: x86: directly modify code. In-Reply-To: <1423743476-11927-1-git-send-email-wangnan0@huawei.com> References: <1423743476-11927-1-git-send-email-wangnan0@huawei.com> Message-ID: <1423743640-12674-1-git-send-email-wangnan0@huawei.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org When registering early kprobes, SMP should has not been enabled, so doesn't require synchronization in text_poke_bp(). Simply memcpy is enough. Signed-off-by: Wang Nan --- 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 #include #include +#include #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); } -- 1.8.4