Jim Keniston wrote:
On Fri, 2009-04-03 at 12:02 -0400, Masami Hiramatsu wrote:
Ensure safeness of inserting kprobes by checking whether the specified
address is at the first byte of a instruction. This is done by decoding
probed function from its head to the probe point.
changes from v4:
- change a comment according to Ananth's suggestion.
Signed-off-by: Masami Hiramatsu mhira...@redhat.com
Cc: Ananth N Mavinakayanahalli ana...@in.ibm.com
Cc: Jim Keniston jkeni...@us.ibm.com
Cc: Ingo Molnar mi...@elte.hu
---
arch/x86/kernel/kprobes.c | 51
+
1 files changed, 51 insertions(+), 0 deletions(-)
diff --git a/arch/x86/kernel/kprobes.c b/arch/x86/kernel/kprobes.c
...
+/* Recover original instruction */
/* Recover the probed instruction at addr for further analysis. */
See below.
Sure.
+static int recover_probed_instruction(kprobe_opcode_t *buf, unsigned long
addr)
+{
+struct kprobe *kp;
+kp = get_kprobe((void *)addr);
+if (!kp)
+return -EINVAL;
+
+/* Don't use p-ainsn.insn; which will be modified by fix_riprel */
fix_riprel doesn't affect the instruction's length, which is what
concerns this patch. But we want this function to be useful for
unforeseen uses as well, so I like the code you have. Just consider the
suggested comment changes.
/*
* Don't use p-ainsn.insn, which could be modified -- e.g.,
* by fix_riprel().
*/
Thanks, I'll update comments then!
+memcpy(buf, kp-addr, MAX_INSN_SIZE * sizeof(kprobe_opcode_t));
+buf[0] = kp-opcode;
+return 0;
+}
Jim Keniston
--
To unsubscribe from this list: send the line unsubscribe linux-kernel in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
--
Masami Hiramatsu
Software Engineer
Hitachi Computer Products (America) Inc.
Software Solutions Division
e-mail: mhira...@redhat.com
--
To unsubscribe from this list: send the line unsubscribe kvm in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
