Re: [PATCH 3/3] Make jprobes a little safer for users

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On 6/26/07, Michael Ellerman <[email protected]> wrote:

We can then use that in register_jprobe() to check that the entry point
we're passed is actually in the kernel text, rather than just some random
value.

A similar cleanup is possible even for return probes then. I wonder if
there are any kprobe related scenarios where the executable code may
be located outside the core kernel text region (e.g, ITCM?). In that
case would it also be wrong to assume that the jprobe handler may be
situated outside the kernel core text / module  region? Would it then
make sense to move this check from register_jprobe() to the arch
dependent code?

 int __kprobes register_jprobe(struct jprobe *jp)
 {
+       unsigned long addr = arch_deref_entry_point(jp->entry);
+
+       if (!kernel_text_address(addr))
+               return -EINVAL;

Seems like you're checking for the jprobe handler to be within
kernel/module range. Why not narrow this down to just module range
(!module_text_address(addr), say)? Core kernel functions would not be
ending with a 'jprobe_return()' anyway.

--
Abhishek Sagar

-
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/
-
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]
  Powered by Linux