Re: [EXT] Re: [PATCH 1/2] mmc: Support kmsg dumper based on pstore/blk

[Kees Cook]

On Tue, Dec 15, 2020 at 12:42:58PM +0100, Ulf Hansson wrote:
> In principle, for non atomic path, I would rather see that the pstore
> file system should be able to be mounted on top of any generic block
> device partition - without requiring the block device driver to
> implement specific pstore ops.
> [...]
> Exactly. That's why I wonder if it's really worth it to support the
> panic writes at all.

pstore/blk already provides the generic hooking -- but it can't do
the panic write part (which that's very device/driver-specific). The
design was for individual backing devices to provide that directly
(which would needed read/write support too). And for those that don't
have panic/read/write support, they could still use the generic hooks
but they wouldn't be able to reliably (or at all?) catch panics (just
console writes, ftrace, pmsg, etc).

-- 
Kees Cook