Commit b12eb279 authored by Nicholas Piggin's avatar Nicholas Piggin Committed by Michael Ellerman
Browse files

powerpc/64s: make linear_map_hash_lock a raw spinlock 



This lock is taken while the raw kfence_freelist_lock is held, so it
must also be a raw spinlock, as reported by lockdep when raw lock
nesting checking is enabled.

Signed-off-by: default avatarNicholas Piggin <npiggin@gmail.com>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20221013230710.1987253-3-npiggin@gmail.com
parent 35159b57

arch/powerpc/mm/book3s64/hash_utils.c

+6 −6
Original line number Diff line number Diff line
@@ -1981,7 +1981,7 @@ long hpte_insert_repeating(unsigned long hash, unsigned long vpn, 
}



#if defined(CONFIG_DEBUG_PAGEALLOC) || defined(CONFIG_KFENCE)

static DEFINE_SPINLOCK(linear_map_hash_lock);

static DEFINE_RAW_SPINLOCK(linear_map_hash_lock);



static void kernel_map_linear_page(unsigned long vaddr, unsigned long lmi)

{
@@ -2005,10 +2005,10 @@ static void kernel_map_linear_page(unsigned long vaddr, unsigned long lmi) 
				    mmu_linear_psize, mmu_kernel_ssize);



	BUG_ON (ret < 0);

	spin_lock(&linear_map_hash_lock);

	raw_spin_lock(&linear_map_hash_lock);

	BUG_ON(linear_map_hash_slots[lmi] & 0x80);

	linear_map_hash_slots[lmi] = ret | 0x80;

	spin_unlock(&linear_map_hash_lock);

	raw_spin_unlock(&linear_map_hash_lock);

}



static void kernel_unmap_linear_page(unsigned long vaddr, unsigned long lmi)
@@ -2018,14 +2018,14 @@ static void kernel_unmap_linear_page(unsigned long vaddr, unsigned long lmi) 
	unsigned long vpn = hpt_vpn(vaddr, vsid, mmu_kernel_ssize);



	hash = hpt_hash(vpn, PAGE_SHIFT, mmu_kernel_ssize);

	spin_lock(&linear_map_hash_lock);

	raw_spin_lock(&linear_map_hash_lock);

	if (!(linear_map_hash_slots[lmi] & 0x80)) {

		spin_unlock(&linear_map_hash_lock);

		raw_spin_unlock(&linear_map_hash_lock);

		return;

	}

	hidx = linear_map_hash_slots[lmi] & 0x7f;

	linear_map_hash_slots[lmi] = 0;

	spin_unlock(&linear_map_hash_lock);

	raw_spin_unlock(&linear_map_hash_lock);

	if (hidx & _PTEIDX_SECONDARY)

		hash = ~hash;

	slot = (hash & htab_hash_mask) * HPTES_PER_GROUP;