From: masami.hiramatsu.pt@hitachi•com (Masami Hiramatsu)
To: linux-arm-kernel@lists•infradead.org
Subject: [RFC PATCH v3 15/26] early kprobes: x86: directly modify code.
Date: Fri, 20 Feb 2015 13:00:50 +0900 [thread overview]
Message-ID: <54E6B172.7080604@hitachi.com> (raw)
In-Reply-To: <1423806053-62111-1-git-send-email-wangnan0@huawei.com>
(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 <wangnan0@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.pt at hitachi.com
next prev parent reply other threads:[~2015-02-20 4:00 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-02-13 5:39 [RFC PATCH v3 00/26] Early kprobe: enable kprobes at very early booting stage Wang Nan
2015-02-13 5:40 ` [RFC PATCH v3 01/26] kprobes: set kprobes_all_disarmed earlier to enable re-optimization Wang Nan
2015-02-13 5:40 ` [RFC PATCH v3 02/26] kprobes: makes kprobes/enabled works correctly for optimized kprobes Wang Nan
2015-02-13 5:40 ` [RFC PATCH v3 03/26] kprobes: x86: mark 2 bytes NOP as boostable Wang Nan
2015-02-13 5:40 ` [RFC PATCH v3 04/26] ftrace: don't update record flags if code modification fail Wang Nan
2015-02-13 5:40 ` [RFC PATCH v3 05/26] ftrace/x86: Ensure rec->flags no change when failure occures Wang Nan
2015-02-13 5:40 ` [RFC PATCH v3 06/26] ftrace: sort ftrace entries earlier Wang Nan
2015-02-13 5:40 ` [RFC PATCH v3 07/26] ftrace: allow search ftrace addr before ftrace fully inited Wang Nan
2015-02-13 5:40 ` [RFC PATCH v3 08/26] ftrace: enable make ftrace nop before ftrace_init() Wang Nan
2015-02-13 5:40 ` [RFC PATCH v3 09/26] ftrace: allow fixing code update failure by notifier chain Wang Nan
2015-02-13 5:40 ` [RFC PATCH v3 10/26] ftrace: x86: try to fix ftrace when ftrace_replace_code Wang Nan
2015-02-13 5:40 ` [RFC PATCH v3 11/26] early kprobes: introduce kprobe_is_early for futher early kprobe use Wang Nan
2015-02-13 5:40 ` [RFC PATCH v3 12/26] early kprobes: Add an KPROBE_FLAG_EARLY for early kprobe Wang Nan
2015-02-13 5:40 ` [RFC PATCH v3 13/26] early kprobes: ARM: directly modify code Wang Nan
2015-02-13 5:40 ` [RFC PATCH v3 14/26] early kprobes: ARM: introduce early kprobes related code area Wang Nan
2015-02-13 5:40 ` [RFC PATCH v3 15/26] early kprobes: x86: directly modify code Wang Nan
2015-02-20 4:00 ` Masami Hiramatsu [this message]
2015-02-13 5:40 ` [RFC PATCH v3 16/26] early kprobes: x86: introduce early kprobes related code area Wang Nan
2015-02-13 5:40 ` [RFC PATCH v3 17/26] early kprobes: introduces macros for allocing early kprobe resources Wang Nan
2015-02-13 5:41 ` [RFC PATCH v3 18/26] early kprobes: allows __alloc_insn_slot() from early kprobes slots Wang Nan
2015-02-13 5:41 ` [RFC PATCH v3 19/26] early kprobes: perhibit probing at early kprobe reserved area Wang Nan
2015-02-13 5:41 ` [RFC PATCH v3 20/26] early kprobes: core logic of eraly kprobes Wang Nan
2015-02-13 5:41 ` [RFC PATCH v3 21/26] early kprobes: add CONFIG_EARLY_KPROBES option Wang Nan
2015-02-13 5:41 ` [RFC PATCH v3 22/26] early kprobes: introduce arch_fix_ftrace_early_kprobe() Wang Nan
2015-02-13 5:41 ` [RFC PATCH v3 23/26] early kprobes: x86: arch_restore_optimized_kprobe() Wang Nan
2015-02-13 5:41 ` [RFC PATCH v3 24/26] early kprobes: core logic to support early kprobe on ftrace Wang Nan
2015-02-13 5:41 ` [RFC PATCH v3 25/26] early kprobes: introduce kconfig option " Wang Nan
2015-02-13 5:41 ` [RFC PATCH v3 26/26] kprobes: enable 'ekprobe=' cmdline option for early kprobes Wang Nan
2015-02-20 3:59 ` [RFC PATCH v3 00/26] Early kprobe: enable kprobes at very early booting stage Masami Hiramatsu
2015-02-25 11:11 ` Wang Nan
2015-02-25 11:46 ` Wang Nan
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