Commit 76b7d646 authored by Ritesh Harjani (IBM)'s avatar Ritesh Harjani (IBM) Committed by Michael Ellerman
Browse files

book3s64/hash: Disable kfence if not early init 



Enable kfence on book3s64 hash only when early init is enabled.
This is because, kfence could cause the kernel linear map to be mapped
at PAGE_SIZE level instead of 16M (which I guess we don't want).

Also currently there is no way to -
1. Make multiple page size entries for the SLB used for kernel linear
   map.
2. No easy way of getting the hash slot details after the page table
   mapping for kernel linear setup. So even if kfence allocate the
   pool in late init, we won't be able to get the hash slot details in
   kfence linear map.

Thus this patch disables kfence on hash if kfence early init is not
enabled.

Signed-off-by: default avatarRitesh Harjani (IBM) <ritesh.list@gmail.com>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
Link: https://patch.msgid.link/4a6eea8cfd1cd28fccfae067026bff30cbec1d4b.1729271995.git.ritesh.list@gmail.com
parent b5fbf7e2

arch/powerpc/mm/book3s64/hash_utils.c

+3 −1
Original line number Diff line number Diff line
@@ -410,6 +410,8 @@ static phys_addr_t kfence_pool; 


static inline void hash_kfence_alloc_pool(void)

{

	if (!kfence_early_init_enabled())

		goto err;



	/* allocate linear map for kfence within RMA region */

	linear_map_kf_hash_count = KFENCE_POOL_SIZE >> PAGE_SHIFT;
@@ -1074,7 +1076,7 @@ static void __init htab_init_page_sizes(void) 
	bool aligned = true;

	init_hpte_page_sizes();



	if (!debug_pagealloc_enabled_or_kfence()) {

	if (!debug_pagealloc_enabled() && !kfence_early_init_enabled()) {

		/*

		 * Pick a size for the linear mapping. Currently, we only

		 * support 16M, 1M and 4K which is the default