From: Anshuman Khandual <anshuman.khandual@arm.com>
Date: Thu, 30 Apr 2026 05:38:59 +0000 (+0100)
Subject: arm64/mm: Replace BUG_ON() with VM_WARN_ON_ONCE()
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=13d0fdc0901614f0d6c9066193bca6fe63a70c6e;p=thirdparty%2Fkernel%2Flinux.git

arm64/mm: Replace BUG_ON() with VM_WARN_ON_ONCE()

Avoid BUG_ON() while checking for inconsistent page table state conditions
and instead replace them with VM_WARN_ON_ONCE().

Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: David Hildenbrand <david@kernel.org>
Cc: linux-kernel@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Suggested-by: David Hildenbrand (Arm) <david@kernel.org>
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
---

diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h
index 4dfa42b7d0535..c9e4e00a9af27 100644
--- a/arch/arm64/include/asm/pgtable.h
+++ b/arch/arm64/include/asm/pgtable.h
@@ -1007,7 +1007,7 @@ static inline pud_t *p4d_pgtable(p4d_t p4d)
 
 static inline phys_addr_t pud_offset_phys(p4d_t *p4dp, unsigned long addr)
 {
-	BUG_ON(!pgtable_l4_enabled());
+	VM_WARN_ON_ONCE(!pgtable_l4_enabled());
 
 	return p4d_page_paddr(READ_ONCE(*p4dp)) + pud_index(addr) * sizeof(pud_t);
 }
@@ -1130,7 +1130,7 @@ static inline p4d_t *pgd_to_folded_p4d(pgd_t *pgdp, unsigned long addr)
 
 static inline phys_addr_t p4d_offset_phys(pgd_t *pgdp, unsigned long addr)
 {
-	BUG_ON(!pgtable_l5_enabled());
+	VM_WARN_ON_ONCE(!pgtable_l5_enabled());
 
 	return pgd_page_paddr(READ_ONCE(*pgdp)) + p4d_index(addr) * sizeof(p4d_t);
 }
diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c
index dd85e093ffdb1..4c8959153ac47 100644
--- a/arch/arm64/mm/mmu.c
+++ b/arch/arm64/mm/mmu.c
@@ -273,8 +273,8 @@ static int init_pmd(pmd_t *pmdp, unsigned long addr, unsigned long end,
 			if (ret)
 				return ret;
 
-			BUG_ON(pmd_val(old_pmd) != 0 &&
-			       pmd_val(old_pmd) != READ_ONCE(pmd_val(*pmdp)));
+			VM_WARN_ON_ONCE(pmd_val(old_pmd) != 0 &&
+					pmd_val(old_pmd) != READ_ONCE(pmd_val(*pmdp)));
 		}
 		phys += next - addr;
 	} while (pmdp++, addr = next, addr != end);
@@ -394,8 +394,8 @@ static int alloc_init_pud(p4d_t *p4dp, unsigned long addr, unsigned long end,
 			if (ret)
 				goto out;
 
-			BUG_ON(pud_val(old_pud) != 0 &&
-			       pud_val(old_pud) != READ_ONCE(pud_val(*pudp)));
+			VM_WARN_ON_ONCE(pud_val(old_pud) != 0 &&
+					pud_val(old_pud) != READ_ONCE(pud_val(*pudp)));
 		}
 		phys += next - addr;
 	} while (pudp++, addr = next, addr != end);
@@ -445,8 +445,8 @@ static int alloc_init_p4d(pgd_t *pgdp, unsigned long addr, unsigned long end,
 		if (ret)
 			goto out;
 
-		BUG_ON(p4d_val(old_p4d) != 0 &&
-		       p4d_val(old_p4d) != READ_ONCE(p4d_val(*p4dp)));
+		VM_WARN_ON_ONCE(p4d_val(old_p4d) != 0 &&
+				p4d_val(old_p4d) != READ_ONCE(p4d_val(*p4dp)));
 
 		phys += next - addr;
 	} while (p4dp++, addr = next, addr != end);