Re: [patch V3 05/11] x86/mm/cpa: Add debug mechanism

[Jordan Glover]

Hello,

The patch  "x86/mm/cpa: Add debug mechanism" (https://lore.kernel.org/lkml/20180917143546.078998733@xxxxxxxxxxxxx/) caused a thousands of messages during boot on my machine.

They look like below:

kernel: CPA  protect    Text RO: 0xffffffff8affc000 - 0xffffffff8affcfff PFN 12cffc req 0000000000000063 prevent 0000000000000002
kernel: CPA  protect    Text RO: 0xffffffff8affd000 - 0xffffffff8affdfff PFN 12cffd req 0000000000000063 prevent 0000000000000002
kernel: CPA  protect    Text RO: 0xffffffff8affe000 - 0xffffffff8affefff PFN 12cffe req 0000000000000063 prevent 0000000000000002
kernel: CPA  protect    Text RO: 0xffffffff8afff000 - 0xffffffff8affffff PFN 12cfff req 0000000000000063 prevent 0000000000000002
kernel: CPA conflict  Rodata RO: 0xffffa2fbece00000 - 0xffffa2fbecffffff PFN 12ce00 req 80000000000000e3 prevent 0000000000000002
kernel: CPA  protect  Rodata RO: 0xffffa2fbece00000 - 0xffffa2fbece00fff PFN 12ce00 req 8000000000000063 prevent 0000000000000002
kernel: CPA  protect  Rodata RO: 0xffffa2fbece01000 - 0xffffa2fbece01fff PFN 12ce01 req 8000000000000063 prevent 0000000000000002
kernel: CPA  protect  Rodata RO: 0xffffa2fbece02000 - 0xffffa2fbece02fff PFN 12ce02 req 8000000000000063 prevent 0000000000000002


The exact reason for those may be related to some out-of-tree patches which I use:

https://github.com/anthraxx/linux-hardened/commit/c492687efa253c32972115a5e110e51614af445e#diff-e1f7e9a10ed7feb8c32493438cff8456

https://github.com/anthraxx/linux-hardened/commit/266d16fc47257b2548e6fcbfafebcc5d84d46389#diff-e1f7e9a10ed7feb8c32493438cff8456

but I wonder if those messages shouldn't be rate-limited or hidden behind 'CONFIG_CPA_DEBUG' in general as there may be a chance that someone will trigger something like that with vanillia kernel.

Jordan