diff mbox series

[3/4] powerpc/64s: Allow double call of kernel_[un]map_linear_page()

Message ID 20210517061658.194708-4-jniethe5@gmail.com (mailing list archive)
State Changes Requested
Headers show
Series powerpc/64s: Enable KFENCE | expand
Related show

Checks

Context Check Description
snowpatch_ozlabs/apply_patch warning Failed to apply on branch powerpc/merge (3a81c0495fdb91fd9a9b4f617098c283131eeae1)
snowpatch_ozlabs/apply_patch warning Failed to apply on branch powerpc/next (6efb943b8616ec53a5e444193dccf1af9ad627b5)
snowpatch_ozlabs/apply_patch warning Failed to apply on branch linus/master (d07f6ca923ea0927a1024dfccafc5b53b61cfecc)
snowpatch_ozlabs/apply_patch warning Failed to apply on branch powerpc/fixes (c6ac667b07996929835b512de0e9a988977e6abc)
snowpatch_ozlabs/apply_patch warning Failed to apply on branch linux-next (c12a29ed9094b4b9cde8965c12850460b9a79d7c)
snowpatch_ozlabs/apply_patch fail Failed to apply to any branch

Commit Message

Jordan Niethe May 17, 2021, 6:16 a.m. UTC 
From: Christophe Leroy <christophe.leroy@csgroup.eu>

If the page is already mapped resp. already unmapped, bail out.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Jordan Niethe <jniethe5@gmail.com>
---
 arch/powerpc/mm/book3s64/hash_utils.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/arch/powerpc/mm/book3s64/hash_utils.c b/arch/powerpc/mm/book3s64/hash_utils.c
index d74482cce064..fe5cf1cf4dd5 100644
--- a/arch/powerpc/mm/book3s64/hash_utils.c
+++ b/arch/powerpc/mm/book3s64/hash_utils.c
@@ -1953,6 +1953,9 @@  static void kernel_map_linear_page(unsigned long vaddr, unsigned long lmi)
 	if (!vsid)
 		return;
 
+	if (linear_map_hash_slots[lmi] & 0x80)
+		return;
+
 	ret = hpte_insert_repeating(hash, vpn, __pa(vaddr), mode,
 				    HPTE_V_BOLTED,
 				    mmu_linear_psize, mmu_kernel_ssize);
@@ -1972,7 +1975,10 @@  static void kernel_unmap_linear_page(unsigned long vaddr, unsigned long lmi)
 
 	hash = hpt_hash(vpn, PAGE_SHIFT, mmu_kernel_ssize);
 	spin_lock(&linear_map_hash_lock);
-	BUG_ON(!(linear_map_hash_slots[lmi] & 0x80));
+	if (!(linear_map_hash_slots[lmi] & 0x80)) {
+		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);