x86/mm: Free sme_early_buffer after init

The contents of sme_early_buffer should be cleared after
__sme_early_enc_dec() because it is used to move encrypted and decrypted
data, but since __sme_early_enc_dec() is __init this buffer simply can be
freed after init.

This saves a page that is otherwise unreferenced after init.

Reported-by: Cfir Cohen <cfir@google.com>
Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/alpine.DEB.2.21.1907101318170.197432@chino.kir.corp.google.com
This commit is contained in:
David Rientjes 2019-07-10 13:19:35 -07:00 committed by Thomas Gleixner
parent e74bd96989
commit ffdb07f312

View File

@ -41,7 +41,7 @@ EXPORT_SYMBOL_GPL(sev_enable_key);
bool sev_enabled __section(.data);
/* Buffer used for early in-place encryption by BSP, no locking needed */
static char sme_early_buffer[PAGE_SIZE] __aligned(PAGE_SIZE);
static char sme_early_buffer[PAGE_SIZE] __initdata __aligned(PAGE_SIZE);
/*
* This routine does not change the underlying encryption setting of the