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SubjectRe: [tip:x86/asmlinkage] x86, asmlinkage: Make kprobes code visible and fix assembler code
(2013/08/07 6:43), tip-bot for Andi Kleen wrote:
> Commit-ID: 04bb591ca74fb8ea06d5ab7fadfb7bf5b11fb28e
> Gitweb: http://git.kernel.org/tip/04bb591ca74fb8ea06d5ab7fadfb7bf5b11fb28e
> Author: Andi Kleen <ak@linux.intel.com>
> AuthorDate: Mon, 5 Aug 2013 15:02:41 -0700
> Committer: H. Peter Anvin <hpa@linux.intel.com>
> CommitDate: Tue, 6 Aug 2013 14:19:48 -0700
>
> x86, asmlinkage: Make kprobes code visible and fix assembler code
>
> - Make all the external assembler template symbols __visible
> - Move the templates inline assembler code into a top level
> assembler statement, not inside a function. This avoids it being
> optimized away or cloned.

Oh, I didn't know that I can use asm() at top level. Thanks!

Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>

> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
> Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
> Cc: "David S. Miller" <davem@davemloft.net>
> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
> Signed-off-by: Andi Kleen <ak@linux.intel.com>
> Link: http://lkml.kernel.org/r/1375740170-7446-8-git-send-email-andi@firstfloor.org
> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
> ---
> arch/x86/include/asm/kprobes.h | 10 +++++-----
> arch/x86/kernel/kprobes/core.c | 2 +-
> arch/x86/kernel/kprobes/opt.c | 5 +----
> 3 files changed, 7 insertions(+), 10 deletions(-)
>
> diff --git a/arch/x86/include/asm/kprobes.h b/arch/x86/include/asm/kprobes.h
> index 5a6d287..9454c16 100644
> --- a/arch/x86/include/asm/kprobes.h
> +++ b/arch/x86/include/asm/kprobes.h
> @@ -49,10 +49,10 @@ typedef u8 kprobe_opcode_t;
> #define flush_insn_slot(p) do { } while (0)
>
> /* optinsn template addresses */
> -extern kprobe_opcode_t optprobe_template_entry;
> -extern kprobe_opcode_t optprobe_template_val;
> -extern kprobe_opcode_t optprobe_template_call;
> -extern kprobe_opcode_t optprobe_template_end;
> +extern __visible kprobe_opcode_t optprobe_template_entry;
> +extern __visible kprobe_opcode_t optprobe_template_val;
> +extern __visible kprobe_opcode_t optprobe_template_call;
> +extern __visible kprobe_opcode_t optprobe_template_end;
> #define MAX_OPTIMIZED_LENGTH (MAX_INSN_SIZE + RELATIVE_ADDR_SIZE)
> #define MAX_OPTINSN_SIZE \
> (((unsigned long)&optprobe_template_end - \
> @@ -62,7 +62,7 @@ extern kprobe_opcode_t optprobe_template_end;
> extern const int kretprobe_blacklist_size;
>
> void arch_remove_kprobe(struct kprobe *p);
> -void kretprobe_trampoline(void);
> +asmlinkage void kretprobe_trampoline(void);
>
> /* Architecture specific copy of original instruction*/
> struct arch_specific_insn {
> diff --git a/arch/x86/kernel/kprobes/core.c b/arch/x86/kernel/kprobes/core.c
> index 211bce4..048852d 100644
> --- a/arch/x86/kernel/kprobes/core.c
> +++ b/arch/x86/kernel/kprobes/core.c
> @@ -661,7 +661,7 @@ static void __used __kprobes kretprobe_trampoline_holder(void)
> /*
> * Called from kretprobe_trampoline
> */
> -static __used __kprobes void *trampoline_handler(struct pt_regs *regs)
> +__visible __used __kprobes void *trampoline_handler(struct pt_regs *regs)
> {
> struct kretprobe_instance *ri = NULL;
> struct hlist_head *head, empty_rp;
> diff --git a/arch/x86/kernel/kprobes/opt.c b/arch/x86/kernel/kprobes/opt.c
> index 76dc6f0..2c1ac28 100644
> --- a/arch/x86/kernel/kprobes/opt.c
> +++ b/arch/x86/kernel/kprobes/opt.c
> @@ -88,9 +88,7 @@ static void __kprobes synthesize_set_arg1(kprobe_opcode_t *addr, unsigned long v
> *(unsigned long *)addr = val;
> }
>
> -static void __used __kprobes kprobes_optinsn_template_holder(void)
> -{
> - asm volatile (
> +asm (
> ".global optprobe_template_entry\n"
> "optprobe_template_entry:\n"
> #ifdef CONFIG_X86_64
> @@ -129,7 +127,6 @@ static void __used __kprobes kprobes_optinsn_template_holder(void)
> #endif
> ".global optprobe_template_end\n"
> "optprobe_template_end:\n");
> -}
>
> #define TMPL_MOVE_IDX \
> ((long)&optprobe_template_val - (long)&optprobe_template_entry)

--
Masami HIRAMATSU
IT Management Research Dept. Linux Technology Center
Hitachi, Ltd., Yokohama Research Laboratory
E-mail: masami.hiramatsu.pt@hitachi.com




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