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authorBreno Leitao <leitao@debian.org>2025-12-22 07:28:55 -0800
committerWill Deacon <will@kernel.org>2026-01-22 11:20:29 +0000
commit53f45f045cbe89024d2b71c145c782bb6a82a602 (patch)
tree22177be51c97c8da40df5b73bed6c0fa43c5d480
parentf22c81bebf8bda6e54dc132df0ed54f6bf8756f9 (diff)
arm64: mm: warn once for ioremap attempts on RAM mappings
Replace WARN_ON with WARN_ONCE when detecting attempts to ioremap RAM. This prevents log spam when a misbehaving driver repeatedly tries to map RAM via ioremap. A single warning is more than enough to show the broken code path, and extra reports don't add extra information. Warning floods have been seen in production environments where broken external drivers hit this code path thousand of times, causing unnecessary messages to be printed and pressure on the serial console. Signed-off-by: Breno Leitao <leitao@debian.org> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Will Deacon <will@kernel.org>
-rw-r--r--arch/arm64/mm/ioremap.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/arch/arm64/mm/ioremap.c b/arch/arm64/mm/ioremap.c
index 10e246f11271..b12cbed9b5ad 100644
--- a/arch/arm64/mm/ioremap.c
+++ b/arch/arm64/mm/ioremap.c
@@ -24,7 +24,8 @@ void __iomem *ioremap_prot(phys_addr_t phys_addr, size_t size,
return NULL;
/* Don't allow RAM to be mapped. */
- if (WARN_ON(pfn_is_map_memory(__phys_to_pfn(phys_addr))))
+ if (WARN_ONCE(pfn_is_map_memory(__phys_to_pfn(phys_addr)),
+ "ioremap attempted on RAM pfn\n"))
return NULL;
/*