lkml.org 
[lkml]   [2013]   [Jan]   [21]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH 3/5] kprobes: constify check_kprobe_address_safe and friends
(2013/01/10 8:09), Sasha Levin wrote:
> Constify the parameters of lookup functions.
>
> Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
> ---
> arch/x86/kernel/kprobes-opt.c | 8 ++++----
> kernel/kprobes.c | 2 +-
> 2 files changed, 5 insertions(+), 5 deletions(-)
>
> diff --git a/arch/x86/kernel/kprobes-opt.c b/arch/x86/kernel/kprobes-opt.c
> index c5e410e..5876966 100644
> --- a/arch/x86/kernel/kprobes-opt.c
> +++ b/arch/x86/kernel/kprobes-opt.c
> @@ -192,7 +192,7 @@ static int __kprobes copy_optimized_instructions(u8 *dest, u8 *src)
> }
>
> /* Check whether insn is indirect jump */
> -static int __kprobes insn_is_indirect_jump(struct insn *insn)
> +static int __kprobes insn_is_indirect_jump(const struct insn *insn)
> {
> return ((insn->opcode.bytes[0] == 0xff &&
> (X86_MODRM_REG(insn->modrm.value) & 6) == 4) || /* Jump */
> @@ -200,7 +200,7 @@ static int __kprobes insn_is_indirect_jump(struct insn *insn)
> }
>
> /* Check whether insn jumps into specified address range */
> -static int insn_jump_into_range(struct insn *insn, unsigned long start, int len)
> +static int insn_jump_into_range(const struct insn *insn, unsigned long start, int len)
> {
> unsigned long target = 0;
>

These are OK for me.

> @@ -278,7 +278,7 @@ static int __kprobes can_optimize(unsigned long paddr)
> }
>
> /* Check optimized_kprobe can actually be optimized. */
> -int __kprobes arch_check_optimized_kprobe(struct optimized_kprobe *op)
> +int __kprobes arch_check_optimized_kprobe(const struct optimized_kprobe *op)
> {
> int i;
> struct kprobe *p;

This can be change optimized_kprobe inside, e.g. change flags.
IMHO, I don't like to change this interface.

> @@ -294,7 +294,7 @@ int __kprobes arch_check_optimized_kprobe(struct optimized_kprobe *op)
>
> /* Check the addr is within the optimized instructions. */
> int __kprobes
> -arch_within_optimized_kprobe(struct optimized_kprobe *op, unsigned long addr)
> +arch_within_optimized_kprobe(const struct optimized_kprobe *op, unsigned long addr)
> {
> return ((unsigned long)op->kp.addr <= addr &&
> (unsigned long)op->kp.addr + op->optinsn.size > addr);

This is OK for me. But you need to update the prototype in
include/linux/kprobes.h too.

> diff --git a/kernel/kprobes.c b/kernel/kprobes.c
> index 098f396..7daddb0 100644
> --- a/kernel/kprobes.c
> +++ b/kernel/kprobes.c
> @@ -1402,7 +1402,7 @@ static inline int check_kprobe_rereg(struct kprobe *p)
> return ret;
> }
>
> -static __kprobes int check_kprobe_address_safe(struct kprobe *p,
> +static __kprobes int check_kprobe_address_safe(const struct kprobe *p,
> struct module **probed_mod)
> {
> int ret = 0;
>

No, p is NOT constant in this function. This changes p->flags.

---
#ifdef KPROBES_CAN_USE_FTRACE
/* Given address is not on the instruction boundary */
if ((unsigned long)p->addr != ftrace_addr)
return -EILSEQ;
p->flags |= KPROBE_FLAG_FTRACE;
#else /* !KPROBES_CAN_USE_FTRACE */
---

Thank you,

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




\
 
 \ /
  Last update: 2013-01-21 13:44    [W:0.181 / U:3.708 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site