Ananth N Mavinakayanahalli wrote:
On Mon, Mar 28, 2005 at 04:10:32PM -0500, William Cohen wrote:
Hi Will,
I found kprobes expects there to be a pre_handler function in the
structure. I was writing a probe that only needed a post_handler
function, no pre_handler function. The probe was tracking the
destinations of indirect calls and jumps, the probe needs to fire after
the instruction single steps to get the target address. The probe
crashed the machine because arch/i386/kernel/kprobe.c:kprobe_handler()
blindly calls p->pre_handler(). There should be a check to verify that
the pointer is non-null. There are cases where the pre_handler is not
needed and it would make sense to set it to NULL. Thus, a check should
be done for pre_handler like post_handler and fault_handler.
You are right. The check for pre_handler is needed and here is a patch
against 2.6.12-rc1-mm3 that does this.
Thanks,
Ananth
Ananth,
Thanks. It looks like it addresses the problem. Could you see about
getting this patch in the upstream kernel?
-Will
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
[Index of Archives]
[Kernel Newbies]
[Netfilter]
[Bugtraq]
[Photo]
[Stuff]
[Gimp]
[Yosemite News]
[MIPS Linux]
[ARM Linux]
[Linux Security]
[Linux RAID]
[Video 4 Linux]
[Linux for the blind]
[Linux Resources]
