Re: [Fastboot] [PATCH] Kdump(x86): add note type NT_KDUMPINFO tokernel core dumps

[ebiederm@xmission.com (Eric W. Biederman)]

Vivek Goyal <vgoyal@in.ibm.com> writes:

> I got a concern here. Are we not breaking the convention. NT_TASKSTRUCT note
> type represents that task_sturct is stored in note data. elf_core_dump()
> and /proc/kcore already do that (That's a different story that it might not 
> be needed at all). Now if we store a null NT_TASKSTURCT, same note type will
> carry two meanings.

My impression is that NT_TASKSTRUCT has failed to define what actually appears
in the note, as the kernel task_struct is not designed to be exported to
user space, and can change without warning.

Hmm.  NT_TASKSTRUCT feels like an information leak although I haven't
a clue what kernel information you could leak that would be interesting
enough that you could compromise the kernel.  It looks like we should
export NT_TASKSTRUCT until we can decide what goes there.

> IMHO, introducing a null NT_KDUMPINFO will help in that sense, at least 
> there are no two interpretations of same note type. Also it provides the
> scope to add more elements to it if need be.

Agreed.  I was trying too hard to reuse what was already there.

Eric